WO2023109844A1

WO2023109844A1 - Antibodies and uses thereof

Info

Publication number: WO2023109844A1
Application number: PCT/CN2022/138877
Authority: WO
Inventors: Ting MAO; Shensen WANG; Huiyun DA
Original assignee: Doma Biopharmaceutical (Suzhou) Co., Ltd.
Priority date: 2021-12-14
Filing date: 2022-12-14
Publication date: 2023-06-22

Abstract

Provided are antibodies that bind to F protein or G protein of Nipah virus, compositions comprising the antibodies and methods of use.

Description

ANTIBODIES AND USES THEREOF

CLAIM OF PRIORITY

This application claims the benefit of PCT Patent Application No. PCT/CN2021/137683, filed on December 14, 2021. The entire contents of the foregoing application are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to anti-F protein and anti-G protein antibodies and uses thereof.

BACKGROUND

Nipah virus (NiV) is a highly pathogenic new infectious disease pathogen that has emerged in South Asia in recent years (Diederich et al. Molecular characteristics of the Nipah virus glycoproteins. Ann N Y Acad Sci. 2007 Apr; 1102: 39-50) . It is closely related to Cedar virus (CedPV) and Hendra virus (HeV) and all three belong to the family Paramyxoviridae (genus Henipavirus) . From 2015 to 2018, the World Health Organization listed it together with pathogens such as Ebola virus and Marburg virus as the most powerful pathogens that are most likely to cause severe epidemics and are difficult to deal with for four consecutive years. Nipah virus disease is highly contagious, has a high mortality rate, and has a wide distribution of natural hosts. It seriously affects global public health and threatens human life and health. There is an urgent need for treatment of NiV infection.

SUMMARY

This disclosure relates to anti-F protein and anti-G protein antibodies, antigen-binding fragment thereof, and the uses thereof.

In one aspect, the disclosure is related to an anti-F protein antibody or antigen-binding fragment thereof, comprising: a heavy chain variable region (VH) comprising complementarity determining regions (CDRs) 1, 2, and 3, wherein the VH CDR1 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR1 amino acid sequence, the VH CDR2 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR2 amino acid sequence, and the VH CDR3 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR3 amino acid sequence; and a light chain variable region (VL) comprising

CDRs

1, 2, and 3, wherein the VL CDR1 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR1 amino acid sequence, the VL CDR2 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR2 amino acid sequence, and the VL CDR3 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR3 amino acid sequence, wherein the selected

VH CDRs

1, 2, and 3 amino acid sequences and the selected VL CDRs, 1, 2, and 3 amino acid sequences are one of the following:

(1) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 1, 2, 3, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 4, 5, 6, respectively;

(2) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 7, 8, 9, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 10, 11, 12, respectively;

(3) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 13, 14, 15, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 16, 17, 18, respectively.

(4) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 19, 20, 21, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 22, 23, 24, respectively;

(5) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 25, 26, 27, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 28, 29, 30, respectively; or

(6) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 31, 32, 33, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 34, 35, 36, respectively.

In one aspect, the disclosure is related to an anti-G protein antibody or antigen-binding fragment thereof, comprising: a heavy chain variable region (VH) comprising complementarity determining regions (CDRs) 1, 2, and 3, wherein the VH CDR1 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR1 amino acid sequence, the VH CDR2 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR2 amino acid sequence, and the VH CDR3 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR3 amino acid sequence; and a light chain variable region (VL) comprising

CDRs

VH CDRs

(1) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 37, 38, 39, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 40, 41, 42, respectively.

(2) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 43, 44, 45, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 46, 47, 48, respectively;

(3) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 49, 50, 51, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 52, 53, 54, respectively; or

(4) the selected

VH CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 55, 56, 57, respectively, and the selected

VL CDRs

1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 58, 59, 60, respectively.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 1, 2, and 3 respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively according to Kabat numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 7, 8, and 9, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 10, 11, and 12, respectively according to Chothia numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 13, 14, and 15, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 16, 17, and 18, respectively according to Kabat numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 19, 20, and 21, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 22, 23, and 24, respectively according to Chothia numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 25, 26, and 27, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 28, 29, and 30, respectively according to Kabat numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 31, 32, and 33, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 34, 35, and 36, respectively according to Chothia numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 37, 38, and 39, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 40, 41, and 42, respectively according to Kabat numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 43, 44, and 45, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 46, 47, and 48, respectively according to Chothia numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 49, 50, and 51, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 52, 53, and 54, respectively according to Kabat numbering scheme.

In some embodiments, the VH comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 55, 56, and 57, respectively, and the VL comprises

CDRs

1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 58, 59, and 60, respectively according to Chothia numbering scheme.

In some embodiments, the antibody or antigen-binding fragment specifically binds to Nipah virus F protein and/or Hendra virus F protein.

In some embodiments, the antibody or antigen-binding fragment specifically binds to Nipah virus G protein and/or Hendra virus G protein.

In some embodiments, the antibody or antigen-binding fragment is a humanized antibody or antigen-binding fragment thereof (e.g., a human IgG1 antibody) .

In some embodiments, the antibody or antigen-binding fragment is a single-chain variable fragment (scFV) .

In one aspect, the disclosure is related to a nucleic acid comprising a polynucleotide encoding a polypeptide comprising:

(1) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising complementarity determining regions (CDRs) 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 1, 2, and 3, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 62 binds to F protein;

(2) an immunoglobulin light chain or a fragment thereof comprising a

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 61 binds to F protein;

(3) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising

CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 13, 14 and 15, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 64 binds to F protein;

(4) an immunoglobulin light chain or a fragment thereof comprising a

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 16, 17 and 18, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 63 binds to F protein;

(5) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising

CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 25, 26 and 27, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 66 binds to F protein; or

(6) an immunoglobulin light chain or a fragment thereof comprising a

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 28, 29 and 30, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 65 binds to F protein.

(1) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising

CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 37, 38 and 39, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 68 binds to G protein;

(2) an immunoglobulin light chain or a fragment thereof comprising a

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 40, 41 and 42, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 67 binds to G protein;

CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 49, 50 and 51, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 70 binds to G protein; or

(4) an immunoglobulin light chain or a fragment thereof comprising a

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 52, 53 and 54, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 69 binds to G protein.

In some embodiments, the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or a fragment thereof comprising a

VH comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 1, 2, and 3, respectively.

In some embodiments, the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin light chain or a fragment thereof comprising a

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively.

VH comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 13, 14 and 15, respectively.

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 16, 17 and 18, respectively.

VH comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 25, 26 and 27, respectively.

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 28, 29 and 30, respectively.

VH comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 37, 38 and 39, respectively.

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 40, 41 and 42, respectively.

VH comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 49, 50 and 51, respectively.

VL comprising CDRs

1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 52, 53 and 54, respectively.

In some embodiments, the VH when paired with a VL specifically binds to Nipah virus F protein and/or Hendra virus F protein, or the VL when paired with a VH specifically binds to Nipah virus F protein and/or Hendra virus F protein.

In some embodiments, the VH when paired with a VL specifically binds to Nipah virus G protein and/or Hendra virus G protein, or the VL when paired with a VH specifically binds to Nipah virus G protein and/or Hendra virus G protein.

In some embodiments, the immunoglobulin heavy chain or the fragment thereof is a humanized immunoglobulin heavy chain or a fragment thereof, and the immunoglobulin light chain or the fragment thereof is a humanized immunoglobulin light chain or a fragment thereof.

In some embodiments, the nucleic acid encodes a single-chain variable fragment (scFv) .

In some embodiments, the nucleic acid is cDNA.

In one aspect, the disclosure is related to a vector comprising one or more of the nucleic acids described herein.

In one aspect, the disclosure is related to a vector comprising two of the nucleic acids described herein, wherein the vector encodes the VH region and the VL region that together bind to a F protein. In some embodiments, each vector comprises one of the nucleic acids described herein, wherein together the pair of vectors encodes the VH region and the VL region that together bind to a F protein.

In some embodiments, the vector encodes the VH region and the VL region that together bind to a G protein. In some embodiments, each vector comprises one of the nucleic acids described herein, wherein together the pair of vectors encodes the VH region and the VL region that together bind to a G protein.

In one aspect, the disclosure is related to a cell comprising the vector described herein, or the pair of vectors described herein. In some embodiments, the cell is a CHO cell.

In one aspect, the disclosure is related to a cell comprising one or more of the nucleic acids described herein.

In one aspect, the disclosure is related to a cell comprising two of the nucleic acids described herein. In some embodiments, the two nucleic acids together encode the VH region and the VL region that together bind to a F protein or a G protein.

In one aspect, the disclosure is related to a method of producing an antibody or an antigen-binding fragment thereof, the method comprising (a) culturing the cell described herein under conditions sufficient for the cell to produce the antibody or the antigen-binding fragment; and (b) collecting the antibody or the antigen-binding fragment produced by the cell.

In one aspect, the disclosure is related to an anti-F protein antibody or antigen-binding fragment thereof comprising a heavy chain variable region (VH) comprising an amino acid sequence that is at least 80%identical to a selected VH sequence, and a light chain variable region (VL) comprising an amino acid sequence that is at least 80%identical to a selected VL sequence, wherein the selected VH sequence and the selected VL sequence are one of the following:

(1) the selected VH sequence is SEQ ID NO: 61, and the selected VL sequence is SEQ ID NO: 62;

(2) the selected VH sequence is SEQ ID NO: 63, and the selected VL sequence is SEQ ID NO: 64; or

(3) the selected VH sequence is SEQ ID NO: 65, and the selected VL sequence is SEQ ID NO: 66.

In one aspect, the disclosure is related to an anti-G protein antibody or antigen-binding fragment thereof comprising a heavy chain variable region (VH) comprising an amino acid sequence that is at least 80%identical to a selected VH sequence, and a light chain variable region (VL) comprising an amino acid sequence that is at least 80%identical to a selected VL sequence, wherein the selected VH sequence and the selected VL sequence are one of the following:

(1) the selected VH sequence is SEQ ID NO: 67, and the selected VL sequence is SEQ ID NO: 68; or

(2) the selected VH sequence is SEQ ID NO: 69, and the selected VL sequence is SEQ ID NO: 70.

In some embodiments, the VH comprises the sequence of SEQ ID NO: 61 and the VL comprises the sequence of SEQ ID NO: 62.

In some embodiments, the VH comprises the sequence of SEQ ID NO: 63 and the VL comprises the sequence of SEQ ID NO: 64.

In some embodiments, the VH comprises the sequence of SEQ ID NO: 65 and the VL comprises the sequence of SEQ ID NO: 66.

In some embodiments, the VH comprises the sequence of SEQ ID NO: 67 and the VL comprises the sequence of SEQ ID NO: 68.

In some embodiments, the VH comprises the sequence of SEQ ID NO: 69 and the VL comprises the sequence of SEQ ID NO: 70.

In some embodiments, the antibody or antigen-binding fragment is a humanized antibody or antigen-binding fragment thereof.

In one aspect, the disclosure is related to an antibody-drug conjugate comprising the antibody or antigen-binding fragment thereof described herein covalently bound to a therapeutic agent.

In one aspect, the disclosure is related to an antibody or antigen-binding fragment thereof that cross-competes with the antibody or antigen-binding fragment thereof described herein.

In one aspect, the disclosure is related to an antibody or antigen-binding fragment thereof comprising: a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 61; and a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 62.

In one aspect, the disclosure is related to an antibody or antigen-binding fragment thereof comprising: a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 63; and a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 64.

In one aspect, the disclosure is related to an antibody or antigen-binding fragment thereof comprising: a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 65; and a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 66.

In one aspect, the disclosure is related to an antibody or antigen-binding fragment thereof comprising: a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 67; and a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 68.

In one aspect, the disclosure is related to an antibody or antigen-binding fragment thereof comprising: a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 69; and a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 70.

In one aspect, the disclosure is related to a method for reducing the risk of Nipah virus (NiV) infection or treating NiV infection, or at least one symptom associated with the NiV infection in a subject, the method comprising administering a therapeutically effective amount of a composition comprising the antibody or antigen-binding fragment thereof described herein, or the antibody-drug conjugate described herein, to the subject in need thereof.

In some embodiments, the subject has exposure to NiV, NiV infection, or at least one symptom associated with NiV infection.

In some embodiments, the at least one symptom associated with NiV infection is selected from the group consisting of fever, headache, cough, sore throat, difficulty breathing, vomiting, disorientation, drowsiness, confusion, seizures, coma and brain swelling (encephalitis) .

In some embodiments, the at least one symptom associated with NiV infection is fever, headache, cough, sore throat, difficulty breathing or vomiting.

In one aspect, the disclosure is related to a method for reducing the risk of Hendra virus (HeV) infection or treating HeV infection, or at least one symptom associated with HeV infection in a subject, the method comprising administering an effective amount of a composition comprising an antibody or antigen-binding fragment thereof described herein, or the antibody-drag conjugate described herein, to the subject in need thereof.

In some embodiments, the subject has exposure to HeV, HeV infection, or at least one symptom associated with HeV infection.

In some embodiments, the at least one symptom associated with HeV infection is selected from the group consisting of fever, headache, cough, sore throat, difficulty breathing, vomiting, disorientation, drowsiness, confusion, seizures, coma and brain swelling (encephalitis) .

In some embodiments, the at least one symptom associated with HeV infection is fever, headache, cough, sore throat, difficulty breathing or vomiting.

In one aspect, the disclosure is related to a pharmaceutical composition comprising the antibody or antigen-binding fragment thereof described herein, and a pharmaceutically acceptable carrier.

In one aspect, the disclosure is related to a pharmaceutical composition comprising the antibody drug conjugate described herein, and a pharmaceutically acceptable carrier.

The disclosure further provides isolated fully human monoclonal antibodies and antigen-binding fragments thereof that bind specifically to Nipah virus F protein (NiV-F) or Nipah virus G protein (Niv-G) . Given the role that the F protein and G protein play in fusion of the virus with the cell and in cell to cell transmission of the virus, the antibodies described herein provide a method of inhibiting that process and as such, can be used for preventing infection of a subject exposed to, or at risk for acquiring an infection with NiV, or for treating and/or ameliorating one or more symptoms associated with NiV infection in a subject exposed to, or at risk for acquiring an infection with NiV, or suffering from infection with NiV. The antibodies described herein can also be used to prevent or to treat NiV infection in a patient who may experience a more severe form of the NiV infection due to an underlying or pre-existing medical condition.

As used herein, the term “antibody” refers to any antigen-binding molecule that contains at least one (e.g., one, two, three, four, five, or six) complementary determining region (CDR) (e.g., any of the three CDRs from an immunoglobulin light chain or any of the three CDRs from an immunoglobulin heavy chain) and is capable of specifically binding to an epitope. Non-limiting examples of antibodies include: monoclonal antibodies, polyclonal antibodies, multi-specific antibodies (e.g., bi-specific antibodies) , single-chain antibodies, chimeric antibodies, nanobodies, human antibodies, and humanized antibodies. In some embodiments, an antibody can contain an Fc region of a human antibody. The term antibody also includes derivatives, e.g., bi-specific antibodies, single-chain antibodies, diabodies, linear antibodies, and multi-specific antibodies formed from antibody fragments.

As used herein, the term “antigen-binding fragment” refers to a portion of a full-length antibody, wherein the portion of the antibody is capable of specifically binding to an antigen. In some embodiments, the antigen-binding fragment contains at least one variable domain (e.g., a variable domain of a heavy chain or a variable domain of light chain) . Non-limiting examples of antibody fragments include, e.g., Fab, Fab', F (ab') ₂, and Fv fragments.

As used herein, the term “human antibody” refers to an antibody that is encoded by an endogenous nucleic acid (e.g., rearranged human immunoglobulin heavy or light chain locus) derived from a human. In some embodiments, a human antibody is collected from a human or produced in a human cell culture (e.g., human hybridoma cells) . In some embodiments, a human antibody is produced in a non-human cell (e.g., a mouse or hamster cell line) . In some embodiments, a human antibody is produced in a bacterial or yeast cell. In some embodiments, a human antibody is produced in a transgenic non-human animal (e.g., a bovine) containing an unrearranged or rearranged human immunoglobulin locus (e.g., heavy or light chain human immunoglobulin locus) .

As used herein, the term “chimeric antibody” refers to an antibody that contains a sequence present in at least two different species (e.g., antibodies from two different mammalian species such as a human and a mouse antibody) . A non-limiting example of a chimeric antibody is an antibody containing the variable domain sequences (e.g., all or part of a light chain and/or heavy chain variable domain sequence) of a non-human (e.g., mouse) antibody and the constant domains of a human antibody. Additional examples of chimeric antibodies are described herein and are known in the art.

As used herein, the term “humanized antibody” refers to a non-human antibody which contains minimal sequence derived from a non-human (e.g., mouse) immunoglobulin and contains sequences derived from a human immunoglobulin. In non-limiting examples, humanized antibodies are human antibodies (recipient antibody) in which hypervariable (e.g., CDR) region residues of the recipient antibody are replaced by hypervariable (e.g., CDR) region residues from a non-human antibody (e.g., a donor antibody) , e.g., a mouse, rat, or rabbit antibody, having the desired specificity, affinity, and capacity. In some embodiments, the Fv framework residues of the human immunoglobulin are replaced by corresponding non-human (e.g., mouse) immunoglobulin residues. In some embodiments, humanized antibodies may contain residues which are not found in the recipient antibody or in the donor antibody. These modifications can be made to further refine antibody performance. In some embodiments, the humanized antibody contains substantially all of at least one, and typically two, variable domains, in which all or substantially all of the hypervariable loops (CDRs) correspond to those of a non-human (e.g., mouse) immunoglobulin and all or substantially all of the framework regions are those of a human immunoglobulin. The humanized antibody can also contain at least a portion of an immunoglobulin constant region (Fc) , typically, that of a human immunoglobulin. Humanized antibodies can be produced using molecular biology methods known in the art. Non-limiting examples of methods for generating humanized antibodies are described herein.

As used herein, the term “single-chain antibody” refers to a single polypeptide that contains at least two immunoglobulin variable domains (e.g., a variable domain of a mammalian immunoglobulin heavy chain or light chain) that is capable of specifically binding to an antigen. Non-limiting examples of single-chain antibodies are described herein.

As used herein, the term “multimeric antibody” refers to an antibody that contains four or more (e.g., six, eight, or ten) immunoglobulin variable domains.

As used herein, the terms “subject” and “patient” are used interchangeably throughout the specification and describe an animal, human or non-human, to whom treatment according to the methods of the present invention is provided. Veterinary and non-veterinary applications are contemplated in the present disclosure. Human patients can be adult humans or juvenile humans (e.g., humans below the age of 18 years old) . In addition to humans, patients include but are not limited to mice, rats, hamsters, guinea-pigs, rabbits, ferrets, cats, dogs, and primates. Included are, for example, non-human primates (e.g., monkey, chimpanzee, gorilla, and the like) , rodents (e.g., rats, mice, gerbils, hamsters, ferrets, rabbits) , lagomorphs, swine (e.g., pig, miniature pig) , equine, canine, feline, bovine, and other domestic, farm, and zoo animals.

As used herein, when referring to an antibody, the phrases “specifically binding” and “specifically binds” mean that the antibody interacts with its target molecule (e.g., F protein or G protein) preferably to other molecules, because the interaction is dependent upon the presence of a particular structure (i.e., the antigenic determinant or epitope) on the target molecule; in other words, the reagent is recognizing and binding to molecules that include a specific structure rather than to all molecules in general. An antibody that specifically binds to the target molecule may be referred to as a target-specific antibody. For example, an antibody that specifically binds to F protein may be referred to as an F protein specific antibody, an anti-F protein antibody, or an anti-F antibody.

As used herein, the term “F protein” is a fusion protein that mediates cell entry for Paramyxoviridae virus (e.g., Hendra virus and Nipah virus) . In some embodiments, the F protein is Henipavirus F protein. In some embodiments, the F protein is Hendra virus F protein or Nipah virus F protein.

As used herein, the term “Nipah virus F protein, ” also referred to as “NiV-F” is a type I transmembrane protein. After synthesis and cotranslational glycosylation in the ER, the F0 precursor protein oligomerizes into trimers. The F trimers are then transported through the Golgi apparatus to the plasma membrane. Before incorporation into new virions, the F0 precursor is cleaved into the two disulfide-linked subunits F 1 and F2. The F 1 cleavage product derived from the C terminus ofF0 contains several functional domains. The cytoplasmic tail located at the very C terminus has a length of 28 amino acids and has recently been shown to contain a tyrosine-based amino acid motif, which mediates constitutive endocytosis of the NiV F protein. The cytoplasmic domain is followed by the transmembrane domain, which is responsible for anchoring the F protein in lipid membranes. The N terminus of the F 1 subunit is formed by a stretch of about 20 hydrophobic amino acids, the so-called fusion peptide. The fusion peptide is highly conserved among all paramyxoviruses and is indispensable for the biological activity of the F protein. Its role is to insert into the target membrane thereby initiating the fusion process.

As used herein, the term “Hendra virus F protein, ” also referred to as “HeV-F, ” is the fusion protein of Hendra virus.

As used herein, the term “G protein” is an attachment glycoprotein that mediates cell entry for Paramyxoviridae virus (e.g., Hendra virus and Nipah virus) . The G proteins of NiV and HeV bind to the receptor molecule, Ephrin-B2, which is expressed on neurons, smooth muscle, and endothelial cells surrounding small arteries (Ksiazek, Thomas G., et al. “A review of Nipah and Hendra viruses with an historical aside. ” Virus research 162.1-2 (2011) : 173-183) . In some embodiments, the G protein is Henipavirus G protein. In some embodiments, the G protein is Hendra virus G protein or Nipah virus G protein.

As used herein, the term “Nipah virus G protein, ” also referred to as “NiV-G” is the attachment glycoprotein (G) of Nipah virus.

As used herein, the term “Hendra virus G protein, ” also referred to as “HeV-G, ” is the attachment glycoprotein (G) of Hendra virus.

As used herein, the terms “polypeptide, ” “peptide, ” and “protein” are used interchangeably to refer to polymers of amino acids of any length of at least two amino acids.

As used herein, the terms “polynucleotide, ” “nucleic acid molecule, ” and “nucleic acid sequence” are used interchangeably herein to refer to polymers of nucleotides of any length of at least two nucleotides, and include, without limitation, DNA, RNA, DNA/RNA hybrids, and modifications thereof.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Methods and materials are described herein for use in the present invention; other, suitable methods and materials known in the art can also be used. The materials, methods, and examples are illustrative only and not intended to be limiting. All publications, patent applications, patents, sequences, database entries, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control.

Other features and advantages of the invention will be apparent from the following detailed description and figures, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic illustration of an exemplary method to generate mouse anti-F protein and anti-G protein antibodies.

FIG. 2 is a schematic illustration of an exemplary method to generate mouse anti-F protein and anti-G protein antibodies. The method in FIG. 2 is a continuation of the method in FIG. 1.

FIG. 3 lists CDR sequences of anti-F protein antibodies 03-2F6, 03-3C9 and 05-4H8, and anti-G protein antibodies NiG-3D8 and NiG-1G9 as defined by Kabat numbering scheme.

FIG. 4 lists CDR sequences of anti-F protein antibodies 03-2F6, 03-3C9 and 05-4H8, and anti-G protein antibodies NiG-3D8 and NiG-1 G9 as defined by Chothia numbering scheme.

FIG. 5 lists amino acid sequences of heavy chain variable regions and light chain variable regions of antibodies 03-2F6, 03-3C9, 05-4H8, NiG-3D8, NiG-1G9, m102.3, and m5B3.

FIG. 6 shows the sequence alignment of F proteins of different strains of Nipah virus, including NiV-M1 (SEQ ID NO: 71) , NiV-IN1 (SEQ ID NO: 72) , NiV-IN2 (SEQ ID NO: 73) , NiV-B1 (SEQ ID NO: 74) , NiV-B3 (SEQ ID NO: 75) , and NiV-C1 (SEQ ID NO: 76) .

FIG. 7 shows the sequence alignment of F proteins of different strains of Hendra virus, including HeV-A2 (SEQ ID NO: 77) , HeV-A3 (SEQ ID NO: 78) , HeV-A4 (SEQ ID NO: 79) , HeV-A5 (SEQ ID NO: 80) , HeV-A6 (SEQ ID NO: 81) , HeV-A7 (SEQ ID NO: 82) and HeV-A8 (SEQ ID NO: 83) .

FIG. 8 shows data on the interaction of the anti-F protein antibodies to recombinant His-tagged NiV-F protein, as measured by the Biolayer Interferometry (BLI) binding assay.

FIG. 9 shows data on the interaction of the anti-F protein antibodies to recombinant His-tagged HeV-F protein, as measured by the Biolayer Interferometry (BLI) binding assay.

FIG. 10 is a schematic diagram showing the method of calculating inhibition rate.

FIG. 11 shows the sequence alignment of G proteins of different strains of Nipah virus, including NiV-M1 (SEQ ID NO: 88) , NiV-IN1 (SEQ ID NO: 89) , NiV-IN2 (SEQ ID NO: 90) , NiV-B1 (SEQ ID NO: 91) , NiV-B3 (SEQ ID NO: 92) , and NiV-C1 (SEQ ID NO: 93) .

FIG. 12 shows the sequence alignment of G proteins of different strains of Hendra virus, including HeV-A2 (SEQ ID NO: 94) , HeV-A3 (SEQ ID NO: 95) , HeV-A4 (SEQ ID NO: 96) , HeV-A5 (SEQ ID NO: 97) , HeV-A6 (SEQ ID NO: 98) , HeV-A7 (SEQ ID NO: 99) and HeV-A8 (SEQ ID NO: 100) .

DETAILED DESCRIPTION

Nipah virus is a negative-sense, single-stranded, unsegmented, enveloped RNA virus with helical symmetry. Its RNA genome contains a continuous arrangement of six genes from 3'-5', nucleoprotein (N) , phosphoprotein (P) , matrix protein (M) , fusion protein (F) , attachment glycoprotein (G) , and the large protein or RNA polymerase protein (L) . N, P, and L are linked to viral RNA to form viral ribonucleoprotein (vRNP) . M protein mediates virus morphogenesis and budding. F and G proteins are responsible for virus cell attachment and subsequent host cell entry. When Nipah virus infects cells, the G protein first binds to the ephrin receptor on the cell membrane, and then triggers the conformational change of the F protein to form spikes, which mediate the fusion of the viral envelope with the cell membrane, resulting in the delivery of the viral nucleocapsid to the cytoplasm.

F protein is a trimeric type I fusion protein, composed of three domains (DI, DII, and DIII) of a spherical head, a C-terminal domain, a transmembrane (TM) region, and a cytoplasmic tail. At the same time, there are two heptapeptide repeats (HR) , HRA in DIII and HRB in C-terminal domain. The cathepsin cleavage site and the hydrophobic fusion peptide are located in the DIII domain. The F protein has pre-fusion and post-fusion conformations. The precursor protein F0 is cleaved by cathepsin L during the endocytic recycling process to produce mature, disulfide-linked F 1 and F2 subunits. The F 1 subunit contains a viral fusion peptide to drive the fusion of the virus and the host cell membrane for the virus to enter. G protein is a type II homotetrameric transmembrane protein with an ectodomain comprising a stalk and a C-terminal β-propeller head, and the latter domain is responsible for binding to ephrinB2 or ephrinB3 (ephrinB2/B3) receptors (Dang et al. An antibody against the F glycoprotein inhibits Nipah and Hendra virus infections. Nat Struct Mol Biol 26, 980-987 (2019) ) . Nipah virus is closely related to Cedar virus (CedPV) and Hendra virus (HeV) and all three belong to the family Paramyxoviridae (genus Henipavirus) . The sequence homology between different strains of NiV F protein is 99%. The sequence homology ofNiV F protein and HeV F protein is 88%.

In the Henipaviruses, G proteins form tetramers and bind the ubiquitous cellular receptor ephrinB2 or ephrinB3 before undergoing a series of conformational changes, ultimately resulting in the triggering of the metastable F trimer to execute membrane fusion (Bradel-Tretheway, Birgit G., et al. "Nipah and Hendra virus glycoproteins induce comparable homologous but distinct heterologous fusion phenotypes. " Journal of virology 93.13 (2019) : e00577-19) .

According to the information provided in the Clarivate Analytics database, the current NiV drugs are mainly vaccines and monoclonal antibodies. Among them, all except m102.4 are in an inactive state. Among the drugs that target the F protein, the monoclonal antibody h5B3.1 will be combined with ml02.4Ab to treat Nipah virus infection. Among the drags that target the G protein, the monoclonal antibody m102.4 is currently in Phase I.

The present disclosure provides examples of antibodies, antigen-binding fragment thereof, that bind to F protein and/or G protein (e.g., Nipah virus F protein and/or G protein) . In addition, the antibodies as described herein can bind to F proteins and/or G proteins from Nipah virus and Hendra virus (both belong to Henipavirus) . Thus, the antibodies as described herein can provide a broad-spectrum treatment for Henipavirus.

Anti-F protein Antibodies and Antigen-Binding Fragments

The disclosure provides antibodies and antigen-binding fragments thereof that specifically bind to F protein (e.g., NiV-F or HeV-F) . The antibodies and antigen-binding fragments described herein are capable of binding to F protein of Henipavirus.

The disclosure provides e.g., mouse anti-F protein antibodies 03-2F6, 03-3C9 and 05-4H8, the chimeric antibodies thereof, and the humanized antibodies thereof.

The CDR sequences for 03-2F6, and 03-2F6 derived antibodies (e.g., humanized antibodies) include CDRs of the heavy chain variable domain, SEQ ID NOs: 1, 2, 3, and CDRs of the light chain variable domain, SEQ ID NOs: 4, 5, 6 as defined by Kabat numbering. The CDRs can also be defined by Chothia system. Under the Chothia numbering, the CDR sequences of the heavy chain variable domain are set forth in SEQ ID NOs: 7, 8, 9, and CDR sequences of the light chain variable domain are set forth in SEQ ID NOs: 10, 11, 12.

Similarly, the CDR sequences for 03-3C9, and 03-3C9 derived antibodies include CDRs of the heavy chain variable domain, SEQ ID NOs: 13, 14, 15, and CDRs of the light chain variable domain, SEQ ID NOs: 16, 17, 18, as defined by Kabat numbering. Under Chothia numbering, the CDR sequences of the heavy chain variable domain are set forth in SEQ ID NOs: 19, 20, 21, and CDRs of the light chain variable domain are set forth in SEQ ID NOs: 22, 23, 24.

Similarly, the CDR sequences for 05-4H8, and 05-4H8 derived antibodies include CDRs of the heavy chain variable domain, SEQ ID NOs: 25, 26, 27, and CDRs of the light chain variable domain, SEQ ID NOs: 28, 29, 30, as defined by Kabat numbering. Under Chothia numbering, the CDR sequences of the heavy chain variable domain are set forth in SEQ ID NOs: 31, 32, 33, and CDRs of the light chain variable domain are set forth in SEQ ID NOs: 34, 35, 36.

The amino acid sequence for the heavy chain variable region of 03-2F6 antibody is set forth in SEQ ID NO: 61. The amino acid sequence for the light chain variable region of 03-2F6 antibody is set forth in SEQ ID NO: 62. The amino acid sequence for the heavy chain variable region of 03-3C9 antibody is set forth in SEQ ID NO: 63. The amino acid sequence for the light chain variable region of 03-3C9 antibody is set forth in SEQ ID NO: 64. The amino acid sequence for the heavy chain variable region of 05-4H8 antibody is set forth in SEQ ID NO: 65. The amino acid sequence for the light chain variable region of 05-4H8 antibody is set forth in SEQ ID NO: 66.

The amino acid sequences for heavy chain variable regions and light variable regions of the humanized antibodies are also provided. As there are different ways to humanize a mouse antibody (e.g., a sequence can be modified with different amino acid substitutions) , the heavy chain and the light chain of an antibody can have more than one version of humanized sequences. In some embodiments, the humanized heavy chain variable region is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%identical to SEQ ID NO: 61, 63 or 65. In some embodiments, the humanized light chain variable region is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%identical to SEQ ID NO: 62, 64 or 66. The heavy chain variable region sequence can be paired with the corresponding light chain variable region sequence, and together they bind to F protein (e.g., NiV-F or HeV-F) .

Humanization percentage means the percentage identity of the heavy chain or light chain variable region sequence as compared to human antibody sequences in International Immunogenetics Information System (IMGT) database. The top hit means that the heavy chain or light chain variable region sequence is closer to a particular species than to other species. For example, top hit to human means that the sequence is closer to human than to other species. Top hit to human and Macacafascicularis means that the sequence has the same percentage identity to the human sequence and the Macacafascicularis sequence, and these percentages identities are highest as compared to the sequences of other species. In some embodiments, humanization percentage is greater than 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, or 95%. A detailed description regarding how to determine humanization percentage and how to determine top hits is known in the art, and is described, e.g., in Jones, et al. "The INNs and outs of antibody nonproprietary names. " MAbs. Vol. 8. No. 1. Taylor &Francis, 2016, which is incorporated herein by reference in its entirety. A high humanization percentage often has various advantages, e.g., more safe and more effective in humans, more likely to be tolerated by a human subject, and/or less likely to have side effects.

Furthermore, in some embodiments, the antibodies or antigen-binding fragments thereof described herein can also contain one, two, or three heavy chain variable region CDRs selected from the group of SEQ ID NOs: 1-3, SEQ ID NOs: 7-9, SEQ ID NOs: 13-15, SEQ ID NOs: 19-21, SEQ ID NOs: 25-27, and SEQ ID NOs: 31-33; and/or one, two, or three light chain variable region CDRs selected from the group of SEQ ID NOs: 4-6, SEQ ID NOs: 10-12, SEQ ID NOs: 16-18, SEQ ID NOs: 22-24, SEQ ID NOs: 28-30 and SEQ ID NOs: 34-36.

In some embodiments, the antibodies can have a heavy chain variable region (VH) comprising complementarity determining regions (CDRs) 1, 2, 3, wherein the CDR1 region comprises or consists of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VH CDR1 amino acid sequence, the CDR2 region comprises or consists of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VH CDR2 amino acid sequence, and the CDR3 region comprises or consists of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VH CDR3 amino acid sequence. In some embodiments, the antibodies can have a light chain variable region (VL) comprising

CDRs

1, 2, 3, wherein the CDR1 region comprises or consists of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VL CDR1 amino acid sequence, the CDR2 region comprises or consists of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VL CDR2 amino acid sequence, and the CDR3 region comprises or consists of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VL CDR3 amino acid sequence. The selected

VH CDRs

1, 2, 3 amino acid sequences and the selected VL CDRs, 1, 2, 3 amino acid sequences are shown in FIG. 3 (Kabat CDR) and FIG. 4 (Chothia CDR) .

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 1 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 2 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 3 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 7 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 8 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 9 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 13 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 14 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 15 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 19 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 20 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 21 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 25 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 26 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 27 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 31 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 32 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 33 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 4 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 5 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 6 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 10 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 11 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 12 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 16 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 17 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 18 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 22 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 23 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 24 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 28 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 29 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 30 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 34 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 35 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 36 with zero, one or two amino acid insertions, deletions, or substitutions.

The insertions, deletions, and substitutions can be within the CDR sequence, or at one or both terminal ends of the CDR sequence. In some embodiments, the CDR is determined based on Kabat numbering scheme. In some embodiments, the CDR is determined based on Chothia numbering scheme.

The disclosure also provides antibodies or antigen-binding fragments thereof that bind to F protein (e.g., NiV-F or HeV-F) . The antibodies or antigen-binding fragments thereof contain a heavy chain variable region (VH) comprising or consisting of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VH sequence, and a light chain variable region (VL) comprising or consisting of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VL sequence. In some embodiments, the selected VH sequence is SEQ ID NO: 61, and the selected VL sequence is SEQ ID NO: 62. In some embodiments, the selected VH sequence is SEQ ID NO: 63 and the selected VL sequence is SEQ ID NO: 64. In some embodiments, the selected VH sequence is SEQ ID NO: 65 and the selected VL sequence is SEQ ID NO: 66.

To determine the percent identity of two amino acid sequences, or of two nucleic acid sequences, the sequences are aligned for optimal comparison purposes (e.g., gaps can be introduced in one or both of a first and a second amino acid or nucleic acid sequence for optimal alignment and non-homologous sequences can be disregarded for comparison purposes) . The length of a reference sequence aligned for comparison purposes is at least 80%of the length of the reference sequence, and in some embodiments is at least 90%, 95%, or 100%. The amino acid residues or nucleotides at corresponding amino acid positions or nucleotide positions are then compared. When a position in the first sequence is occupied by the same amino acid residue or nucleotide as the corresponding position in the second sequence, then the molecules are identical at that position. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences, taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences. For purposes of illustration, the comparison of sequences and determination of percent identity between two sequences can be accomplished using a Blossum 62 scoring matrix with a gap penalty of 12, a gap extend penalty of 4, and a frameshift gap penalty of 5.

The disclosure also provides nucleic acid comprising a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or an immunoglobulin light chain. The immunoglobulin heavy chain or immunoglobulin light chain comprises CDRs as shown in FIG. 3 or FIG. 4, or have sequences as shown in FIG. 5. When the polypeptides are paired with corresponding polypeptide (e.g., a corresponding heavy chain variable region or a corresponding light chain variable region) , the paired polypeptides bind to F protein (e.g., NiV-F or HeV-F) .

Anti-G protein Antibodies and Antigen-Binding Fragments

The disclosure provides antibodies and antigen-binding fragments thereof that specifically bind to G protein (e.g., NiV-G or HeV-G) . The antibodies and antigen-binding fragments described herein are capable of binding to G protein of Henipaviruses.

The disclosure provides e.g., mouse anti-G protein antibodies NiG-3D8 and NiG-1G9, the chimeric antibodies thereof, and the humanized antibodies thereof.

The CDR sequences for NiG-3D8, and NiG-3D8 derived antibodies (e.g., humanized antibodies) include CDRs of the heavy chain variable domain, SEQ ID NOs: 37, 38, 39, and CDRs of the light chain variable domain, SEQ ID NOs: 40, 41, 42 as defined by Kabat numbering. The CDRs can also be defined by Chothia system. Under the Chothia numbering, the CDR sequences of the heavy chain variable domain are set forth in SEQ ID NOs: 43, 44, 45, and CDR sequences of the light chain variable domain are set forth in SEQ ID NOs: 46, 47, 48.

Similarly, the CDR sequences for NiG-1G9, and NiG-1G9 derived antibodies include CDRs of the heavy chain variable domain, SEQ ID NOs: 49, 50, 51, and CDRs of the light chain variable domain, SEQ ID NOs: 52, 53, 54, as defined by Kabat numbering. Under Chothia numbering, the CDR sequences of the heavy chain variable domain are set forth in SEQ ID NOs: 55, 56, 57, and CDRs of the light chain variable domain are set forth in SEQ ID NOs: 58, 59, 60.

The amino acid sequence for the heavy chain variable region of NiG-3D8 antibody is set forth in SEQ ID NO: 67. The amino acid sequence for the light chain variable region of NiG-3D8 antibody is set forth in SEQ ID NO: 68. The amino acid sequence for the heavy chain variable region of NiG-1G9 antibody is set forth in SEQ ID NO: 69. The amino acid sequence for the light chain variable region of NiG-1G9 antibody is set forth in SEQ ID NO: 70.

The amino acid sequences for heavy chain variable regions and light variable regions of the humanized antibodies are also provided. As there are different ways to humanize a mouse antibody (e.g., a sequence can be modified with different amino acid substitutions) , the heavy chain and the light chain of an antibody can have more than one version of humanized sequences. In some embodiments, the humanized heavy chain variable region is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%identical to SEQ ID NO: 67 or 69. In some embodiments, the humanized light chain variable region is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%identical to SEQ ID NO: 68 or 70. The heavy chain variable region sequence can be paired with the corresponding light chain variable region sequence, and together they bind to G protein (e.g., NiV-G or HeV-G) .

Furthermore, in some embodiments, the antibodies or antigen-binding fragments thereof described herein can also contain one, two, or three heavy chain variable region CDRs selected from the group of SEQ ID NOs: 37-39, SEQ ID NOs: 43-45, SEQ ID NOs: 49-51, and SEQ ID NOs: 55-57; and/or one, two, or three light chain variable region CDRs selected from the group of SEQ ID NOs: 40-42, SEQ ID NOs: 46-48, SEQ ID NOs: 52-54, and SEQ ID Nos: 58-60.

CDRs

VH CDRs

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 37 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 38 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 39 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 43 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 44 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 45 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 49 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 50 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 51 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a heavy chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 55 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 56 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 57 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 40 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 41 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 42 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 46 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 47 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 48 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 52 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 53 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 54 with zero, one or two amino acid insertions, deletions, or substitutions.

In some embodiments, the antibody or an antigen-binding fragment described herein can contain a light chain variable domain containing one, two, or three of the CDRs of SEQ ID NO: 58 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 59 with zero, one or two amino acid insertions, deletions, or substitutions; SEQ ID NO: 60 with zero, one or two amino acid insertions, deletions, or substitutions.

The disclosure also provides antibodies or antigen-binding fragments thereof that bind to G protein (e.g., NiV-G or HeV-G) . The antibodies or antigen-binding fragments thereof contain a heavy chain variable region (VH) comprising or consisting of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VH sequence, and a light chain variable region (VL) comprising or consisting of an amino acid sequence that is at least 80%, 85%, 90%, or 95%identical to a selected VL sequence. In some embodiments, the selected VH sequence is SEQ ID NO: 67 and the selected VL sequence is SEQ ID NO: 68. In some embodiments, the selected VH sequence is SEQ ID NO: 69 and the selected VL sequence is SEQ ID NO: 70.

The disclosure also provides nucleic acid comprising a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or an immunoglobulin light chain. The immunoglobulin heavy chain or immunoglobulin light chain comprises CDRs as shown in FIG. 3 or FIG. 4, or have sequences as shown in FIG. 5. When the polypeptides are paired with corresponding polypeptide (e.g., a corresponding heavy chain variable region or a corresponding light chain variable region) , the paired polypeptides bind to G protein (e.g., NiV-G or HeV-G) .

Antibodies and Antigen Binding Fragments

The present disclosure provides various antibodies and antigen-binding fragments thereof derived from anti-F protein and/or anti-G protein antibodies described herein. In general, antibodies (also called immunoglobulins) are made up of two classes of polypeptide chains, light chains and heavy chains. A non-limiting examples of antibody of the present disclosure can be an intact, four immunoglobulin chain antibody comprising two heavy chains and two light chains. The heavy chain of the antibody can be of any isotype including IgM, IgG, IgE, IgA, or IgD or sub-isotype including IgG1, IgG2, IgG2a, IgG2b, IgG3, IgG4, IgE1, IgE2, etc. The light chain can be a kappa light chain or a lambda light chain. An antibody can comprise two identical copies of a light chain and two identical copies of a heavy chain. The heavy chains, which each contain one variable domain (or variable region, V _H) and multiple constant domains (or constant regions) , bind to one another via disulfide bonding within their constant domains to form the “stem” of the antibody. The light chains, which each contain one variable domain (or variable region, VL) and one constant domain (or constant region) , each bind to one heavy chain via disulfide binding. The variable region of each light chain is aligned with the variable region of the heavy chain to which it is bound. The variable regions of both the light chains and heavy chains contain three hypervariable regions sandwiched between more conserved framework regions (FR) .

These hypervariable regions, known as the complementary determining regions (CDRs) , form loops that comprise the antigen binding surface of the antibody. The four framework regions largely adopt a beta-sheet conformation and the CDRs form loops connecting the beta-sheet structure, and in some cases forming part of, the beta-sheet structure. The CDRs in each chain are held in close proximity by the framework regions and, with the CDRs from the other chain, contribute to the formation of the antigen-binding region.

Methods for identifying the CDR regions of an antibody by analyzing the amino acid sequence of the antibody are well known, and a number of definitions of the CDRs are commonly used. The Kabat definition is based on sequence variability, and the Chothia definition is based on the location of the structural loop regions. These methods and definitions are described in, e.g., Martin, "Protein sequence and structure analysis of antibody variable domains, " Antibody engineering, Springer Berlin Heidelberg, 2001.422-439; Abhinandan, et al. "Analysis and improvements to Kabat and structurally correct numbering of antibody variable domains, " Molecular immunology 45.14 (2008) : 3832-3839; Wu, T.T. and Kabat, E.A. (1970) J. Exp. Med. 132: 211-250; Martin et al., Methods Enzymol. 203: 121-53 (1991) ; Morea et al., Biophys Chem. 68 (1-3) : 9-16 (Oct. 1997) ; Morea et al., J Mol Biol. 275 (2) : 269-94 (Jan. 1998) ; Chothia et al., Nature 342 (6252) : 877-83 (Dec. 1989) ; Ponomarenko and Bourne, BMC Structural Biology 7: 64 (2007) ; each of which is incorporated herein by reference in its entirety.

The CDRs are important for recognizing an epitope of an antigen. As used herein, an “epitope” is the smallest portion of a target molecule capable of being specifically bound by the antigen binding domain of an antibody. The minimal size of an epitope may be about three, four, five, six, or seven amino acids, but these amino acids need not be in a consecutive linear sequence of the antigen's primary structure, as the epitope may depend on an antigen's three-dimensional configuration based on the antigen's secondary and tertiary structure.

In some embodiments, the antibody is an intact immunoglobulin molecule (e.g., IgG1, IgG2a, IgG2b, IgG3, IgM, IgD, IgE, IgA) . The IgG subclasses (IgG1, IgG2, IgG3, and IgG4) are highly conserved, differ in their constant region, particularly in their hinges and upper CH2 domains. The sequences and differences of the IgG subclasses are known in the art, and are described, e.g., in Vidarsson, et al, "IgG subclasses and allotypes: from structure to effector functions. " Frontiers in immunology 5 (2014) ; Irani, et al. "Molecular properties of human IgG subclasses and their implications for designing therapeutic monoclonal antibodies against infectious diseases. " Molecular immunology 67.2 (2015) : 171-182; Shakib, Farouk, ed. The human IgG subclasses: molecular analysis of structure, function and regulation. Elsevier, 2016; each of which is incorporated herein by reference in its entirety.

The antibody can also be an immunoglobulin molecule that is derived from any species (e.g., human, rodent, mouse, camelid) . Antibodies disclosed herein also include, but are not limited to, polyclonal, monoclonal, monospecific, polyspecific antibodies, and chimeric antibodies that include an immunoglobulin binding domain fused to another polypeptide. The term “antigen binding domain” or “antigen binding fragment” is a portion of an antibody that retains specific binding activity of the intact antibody, i.e., any portion of an antibody that is capable of specific binding to an epitope on the intact antibody's target molecule. It includes, e.g., Fab, Fab', F (ab') 2, and variants of these fragments. Thus, in some embodiments, an antibody or an antigen binding fragment thereof can be, e.g., a scFv, a Fv, a Fd, a dAb, a bispecific antibody, a bispecific scFv, a diabody, a linear antibody, a single-chain antibody molecule, a multi-specific antibody formed from antibody fragments, and any polypeptide that includes a binding domain which is, or is homologous to, an antibody binding domain. Non-limiting examples of antigen binding domains include, e.g., the heavy chain and/or light chain CDRs of an intact antibody, the heavy and/or light chain variable regions of an intact antibody, full length heavy or light chains of an intact antibody, or an individual CDR from either the heavy chain or the light chain of an intact antibody.

The antibodies and antigen-binding fragments can also be antibody variants (including derivatives and conjugates) of antibodies or antibody fragments and multi-specific (e.g., bi-specific) antibodies or antibody fragments. Additional antibodies provided herein are polyclonal, monoclonal, multimeric, multi-specific (e.g., bi-specific) , human antibodies, chimeric antibodies (e.g., human-mouse chimera) , single-chain antibodies, intracellularly-made antibodies (i.e., intrabodies) , and antigen-binding fragments thereof. The antibodies or antigen-binding fragments thereof can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, and IgY) , class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2) , or subclass. In some embodiments, the antibody or antigen-binding fragment thereof is an IgG antibody or antigen-binding fragment thereof.

Fragments of antibodies are suitable for use in the methods provided so long as they retain the desired affinity and specificity of the full-length antibody. Thus, a fragment of an antibody that binds to F protein and/or G protein will retain an ability to bind to F protein and/or G protein. An Fv fragment is an antibody fragment which contains a complete antigen recognition and binding site. This region consists of a dimer of one heavy and one light chain variable domain in tight association, which can be covalent in nature, for example in scFv. It is in this configuration that the three CDRs of each variable domain interact to define an antigen binding site on the surface of the VH-VL dimer. Collectively, the six CDRs or a subset thereof confer antigen binding specificity to the antibody. However, even a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) can have the ability to recognize and bind antigen, although usually at a lower affinity than the entire binding site. Single-chain Fv or (scFv) antibody fragments comprise the VH and VL domains (or regions) of antibody, wherein these domains are present in a single polypeptide chain. Generally, the scFv polypeptide further comprises a polypeptide linker between the VH and VL domains, which enables the scFv to form the desired structure for antigen binding.

The present disclosure also provides an antibody or antigen-binding fragment thereof that cross-competes with any antibody or antigen-binding fragment as described herein. The cross-competing assay is known in the art, and is described e.g., in Moore et al., "Antibody cross-competition analysis of the human immunodeficiency virus type 1 gp 120 exterior envelope glycoprotein. " Journal of virology 70.3 (1996) : 1863-1872, which is incorporated herein reference in its entirety. In one aspect, the present disclosure also provides an antibody or antigen-binding fragment thereof that binds to the same epitope or region as any antibody or antigen-binding fragment as described herein. The epitope binning assay is known in the art, and is described e.g., in Estep et al. "High throughput solution-based measurement of antibody-antigen affinity and epitope binning. " MAbs. Vol. 5. No. 2. Taylor &Francis, 2013, which is incorporated herein reference in its entirety.

Fragments of antibodies are suitable for use in the methods described herein are also provided. The Fab fragment contains a variable and constant domain of the light chain and a variable domain and the first constant domain (CH1) of the heavy chain. F (ab') 2 antibody fragments comprise a pair of Fab fragments which are generally covalently linked near their carboxy termini by hinge cysteines between them. Other chemical couplings of antibody fragments are also known in the art.

Diabodies are small antibody fragments with two antigen-binding sites, which fragments comprise a VH connected to a VL in the same polypeptide chain (VH and VL) . By using a linker that is too short to allow pairing between the two domains on the same chain, the domains are forced to pair with the complementary domains of another chain and create two antigen-binding sites.

Linear antibodies comprise a pair of tandem Fd segments (VH-CH1-VH-CH1) which, together with complementary light chain polypeptides, form a pair of antigen binding regions. Linear antibodies can be bispecific or monospecific.

Antibodies and antibody fragments of the present disclosure can be modified in the Fc region to provide desired effector functions or serum half-life.

Multimerization of antibodies may be accomplished through natural aggregation of antibodies or through chemical or recombinant linking techniques known in the art. For example, some percentage of purified antibody preparations (e.g., purified IgG1 molecules) spontaneously form protein aggregates containing antibody homodimers and other higher-order antibody multimers.

Alternatively, antibody homodimers may be formed through chemical linkage techniques known in the art. For example, heterobifunctional crosslinking agents including, but not limited to SMCC (succinimidyl 4- (maleimidomethyl) cyclohexane-1-carboxylate) and SATA (N-succinimidyl S-acethylthio-acetate) can be used to form antibody multimers. An exemplary protocol for the formation of antibody homodimers is described in Ghetie et al. (Proc. Natl. Acad. Sci. U.S.A. 94: 7509-7514, 1997) . Antibody homodimers can be converted to Fab' ₂ homodimers through digestion with pepsin. Another way to form antibody homodimers is through the use of the autophilic T15 peptide described in Zhao et al. (J. Immunol. 25: 396-404, 2002) .

In some embodiments, the multi-specific antibody is a bi-specific antibody. Bi-specific antibodies can be made by engineering the interface between a pair of antibody molecules to maximize the percentage ofheterodimers that are recovered from recombinant cell culture. For example, the interface can contain at least a part of the CH3 domain of an antibody constant domain. In this method, one or more small amino acid side chains from the interface of the first antibody molecule are replaced with larger side chains (e.g., tyrosine or tryptophan) . Compensatory “cavities” of identical or similar size to the large side chain (s) are created on the interface of the second antibody molecule by replacing large amino acid side chains with smaller ones (e.g., alanine or threonine) . This provides a mechanism for increasing the yield of the heterodimer over other unwanted end-products such as homodimers. This method is described, e.g., in WO 96/27011, which is incorporated by reference in its entirety.

Bi-specific antibodies include cross-linked or “heteroconjugate” antibodies. For example, one of the antibodies in the heteroconjugate can be coupled to avidin and the other to biotin. Heteroconjugate antibodies can also be made using any convenient cross-linking methods. Suitable cross-linking agents and cross-linking techniques are well known in the art and are disclosed in U.S. Patent No. 4,676,980, which is incorporated herein by reference in its entirety.

Any of the antibodies or antigen-binding fragments described herein may be conjugated to a stabilizing molecule (e.g., a molecule that increases the half-life of the antibody or antigen-binding fragment thereof in a subject or in solution) . Non-limiting examples of stabilizing molecules include: a polymer (e.g., a polyethylene glycol) or a protein (e.g., serum albumin, such as human serum albumin) . The conjugation of a stabilizing molecule can increase the half-life or extend the biological activity of an antibody or an antigen-binding fragment in vitro (e.g., in tissue culture or when stored as a pharmaceutical composition) or in vivo (e.g., in a human) .

In some embodiments, the antibodies or antigen-binding fragments described herein can be conjugated to a therapeutic agent. The antibody-drug conjugate comprising the antibody or antigen-binding fragment thereof can covalently or non-covalently bind to a therapeutic agent. In some embodiments, the therapeutic agent is a cytotoxic or cytostatic agent (e.g., cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicin, doxorubicin, daunorubicin, dihydroxy anthracin, maytansinoids such as DM-1 and DM-4, dione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, puromycin, epirubicin, and cyclophosphamide and analogs) . In some embodiments, the therapeutic agent is an antiviral agent, a vaccine specific for Nipah virus (NiV) , a vaccine specific for influenza virus, a vaccine specific for Hendra virus (HeV) , an siRNA specific for an NiV RNA or a HeV RNA, a second antibody specific for an NiV antigen or a HeV antigen, an anti-IL4R antibody, an antibody specific for an influenza virus antigen, an anti-NiV-G antibody, or a NSAID.

In some embodiments, the scFV has one heavy chain variable domain, and one light chain variable domain. In some embodiments, the scFV has two heavy chain variable domains, and two light chain variable domains.

Antibody Characteristics

In some embodiments, the antibodies or antigen-binding fragments thereof described herein can inhibit F protein mediated cell entry of virus. In some embodiments, by binding to F protein, the antibody can inhibit F protein mediated membrane fusion. Thus, in some cases, the antibodies or antigen-binding fragments thereof described herein can inhibit virus replication or virus infection and reduce virus load.

In some implementations, the anti-F protein antibody (or antigen-binding fragments thereof) specifically binds to F protein (e.g., NiV-F or HeV-F) with a dissociation rate (koff) of less than 0.1 s ^-1, less than 0.01 s ^-1, less than 0.001 s ^-1, less than 0.0001 s ^-1, or less than 0.00001 s ^-1. In some embodiments, the dissociation rate (koff) is greater than 0.01 s ^-1, greater than 0.001 s ^-1, greater than 0.0001 s ^-1, greater than 0.00001 s ^-1, or greater than 0.000001 s ^-1.

In some embodiments, the antibodies or antigen-binding fragments thereof described herein can inhibit G protein mediated cell entry of virus. In some embodiments, by binding to G protein, the antibody can inhibit G protein mediated membrane fusion. Thus, in some cases, the antibodies or antigen-binding fragments thereof described herein can inhibit virus replication or virus infection and reduce virus load.

In some implementations, the anti-G protein antibody (or antigen-binding fragments thereof) specifically binds to G protein (e.g., NiV-G or HeV-G) with a dissociation rate (koff) of less than 0.1 s ^-1, less than 0.01 s ^-1, less than 0.001 s ^-1, less than 0.0001 s ^-1, or less than 0.00001 s ^-1. In some embodiments, the dissociation rate (koff) is greater than 0.01 s ^-1, greater than 0.001 s ^-1, greater than 0.0001 s ^-1, greater than 0.00001 s ^-1, or greater than 0.000001 s ^-1.

In some embodiments, kinetic association rates (kon) is greater than 1 x 102/Ms, greater than 1 x 10 ³/Ms, greater than 1 x 10 ⁴/Ms, greater than 1 x 10 ⁵/Ms, or greater than 1 x 10 ⁶/Ms. In some embodiments, kinetic association rates (kon) is less than 1 x 10 ⁵/Ms, less than 1 x 10 ⁶/Ms, or less than 1 x 10 ⁷/Ms.

Affinities can be deduced from the quotient of the kinetic rate constants (KD=koff/kon) . In some embodiments, KD is less than 1 x 10 ^-6M, less than 1 x 10 ^-7 M, less than 1 x 10 ^-8 M, less than 1 x 10 ^-9 M, or less than 1 x 10 ^-10 M. In some embodiments, the KD is less than 50nM, 30 nM, 20 nM, 15 nM, 10 nM, 9 nM, 8 nM, 7 nM, 6 nM, 5 nM, 4 nM, 3 nM, 2 nM, or 1 nM. In some embodiments, KD is greater than 1 x 10 ^-7 M, greater than 1 x 10 ^-8 M, greater than 1 x 10 ^-9 M, greater than 1 x 10 ^-10 M, greater than 1 x 10 ^-11 M, or greater than 1 x 10 ^-12 M.

General techniques for measuring the affinity of an antibody for an antigen include, e.g., ELISA, RIA, Biolayer Interferometry (BLI) and surface plasmon resonance (SPR) .

In some embodiments, the antibodies or antigen binding fragments thereof can bind to the extracellular region, the C-terminal domain, or the transmembrane (TM) region of the F protein. In some embodiments, the antibodies or antigen binding fragments thereof can bind to DI, DII, or DIII of the spherical head of the F protein. In some embodiments, the antibodies or antigen binding fragments thereof can bind to the F protein in either or both of the pre-fusion and post-fusion conformations. In some embodiments, the antibodies or antigen binding fragments thereof can bind to the Fl subunit or F2 subunit.

In some embodiments, the Fc region is human IgG1, human IgG2, human IgG3, or human IgG4. In some embodiments, the antibody is a human IgG1 antibody.

In some embodiments, the antibodies or antigen binding fragments do not have a functional Fc region. For example, the antibodies or antigen binding fragments are Fab, Fab', F (ab') 2, and Fv fragments. In some embodiments, the Fc region has LALA mutations (L234A and L235A mutations in EU numbering) , or LALA-PG mutations (L234A, L235A, P329G mutations in EU numbering) .

In some embodiments, the antibodies or antigen binding fragments thereof can effectively neutralize NiV or HeV. In some embodiments, the EC50 for neutralization is less than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 ng/mL. In some embodiments, the virus is a specific NiV virus strain, NiV-M1, NiV-IN1, NiV-IN2, NiV-B1, or NiV-B3. In some embodiments, the virus is a specific HeV virus strain, e.g., HeV-A2, HeV-A3, HeV-A4, HeV-A5, HeV-A6, HeV-A7, or HeV-A8. In some embodiments, for all NiV virus strain (e.g., NiV-M1, NiV-IN1, NiV-IN2, NiV-B 1, and/or NiV-B3) , the EC50 for neutralization is less than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 ng/mL. In some embodiments, for all HeV virus strain (e.g., HeV-A2, HeV-A3, HeV-A4, HeV-A5, HeV-A6, HeV-A7, and/or HeV-A8) , the EC50 for neutralization is less than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 ng/mL.

Methods of Making Antibodies

An isolated fragment of F protein (e.g., NiV-F or HeV-F) or G protein (e.g., NiV-G or HeV-G) can be used as an immunogen to generate antibodies using standard techniques for polyclonal and monoclonal antibody preparation. Polyclonal antibodies can be raised in animals by multiple injections (e.g., subcutaneous or intraperitoneal injections) of an antigenic peptide or protein. In some embodiments, the antigenic peptide or protein is injected with at least one adjuvant. In some embodiments, the antigenic peptide or protein can be conjugated to an agent that is immunogenic in the species to be immunized. Animals can be injected with the antigenic peptide or protein more than one time (e.g., twice, three times, or four times) .

The full-length polypeptide or protein can be used or, alternatively, antigenic peptide fragments thereof can be used as immunogens. The antigenic peptide of a protein comprises at least 8 (e.g., at least 10, 15, 20, or 30) amino acid residues of the amino acid sequence ofFF protein or G protein, and encompasses an epitope of the protein such that an antibody raised against the peptide forms a specific immune complex with the protein. In some embodiments, the full length sequence ofFF protein is selected from SEQ ID NOs: 71-83. In some embodiments, the full length sequence of G protein is selected from SEQ ID NOs: 88-100.

An immunogen typically is used to prepare antibodies by immunizing a suitable subject (e.g., human or transgenic animal expressing at least one human immunoglobulin locus) . An appropriate immunogenic preparation can contain, for example, a recombinantly-expressed or a chemically-synthesized polypeptide (e.g., a fragment of F protein or G protein) . The preparation can further include an adjuvant, such as Freund's complete or incomplete adjuvant, or a similar immunostimulatory agent.

Polyclonal antibodies can be prepared as described above by immunizing a suitable subject with F protein or G protein, or an antigenic peptide thereof (e.g., part of F protein or G protein) as an immunogen. The antibody titer in the immunized subject can be monitored over time by standard techniques, such as with an enzyme-linked immunosorbent assay (ELISA) using the immobilized F protein or G protein. If desired, the antibody molecules can be isolated from the mammal (e.g., from the blood) and further purified by well-known techniques, such as protein A of protein G chromatography to obtain the IgG fraction. At an appropriate time after immunization, e.g., when the specific antibody titers are highest, antibody-producing cells can be obtained from the subject and used to prepare monoclonal antibodies by standard techniques, such as the hybridoma technique originally described by Kohler et al. (Nature 256: 495-497, 1975) , the human B cell hybridoma technique (Kozbor et al., Immunol. Today 4: 72, 1983) , the EBV-hybridoma technique (Cole et al., Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp. 77-96, 1985) , or trioma techniques. The technology for producing hybridomas is well known (see, generally, Current Protocols in Immunology, 1994, Coligan et al. (Eds. ) , John Wiley &Sons, Inc., New York, NY) . Hybridoma cells producing a monoclonal antibody are detected by screening the hybridoma culture supernatants for antibodies that bind the polypeptide or epitope of interest, e.g., using a standard ELISA or FACS assay.

Variants of the antibodies or antigen-binding fragments described herein can be prepared by introducing appropriate nucleotide changes into the DNA encoding a human, humanized, or chimeric antibody, or antigen-binding fragment thereof described herein, or by peptide synthesis. Such variants include, for example, deletions, insertions, or substitutions of residues within the amino acids sequences that make-up the antigen-binding site of the antibody or an antigen-binding domain. In a population of such variants, some antibodies or antigen-binding fragments will have increased affinity for the target protein, e.g., F protein or G protein. Any combination of deletions, insertions, and/or combinations can be made to arrive at an antibody or antigen-binding fragment thereof that has increased binding affinity for the target. The amino acid changes introduced into the antibody or antigen-binding fragment can also alter or introduce new post-translational modifications into the antibody or antigen-binding fragment, such as changing (e.g., increasing or decreasing) the number of glycosylation sites, changing the type of glycosylation site (e.g., changing the amino acid sequence such that a different sugar is attached by enzymes present in a cell) , or introducing new glycosylation sites.

Antibodies disclosed herein can be derived from any species of animal, including mammals. Non-limiting examples of native antibodies include antibodies derived from humans, primates, e.g., monkeys and apes, cows, pigs, horses, sheep, camelids (e.g., camels and llamas) , chicken, goats, and rodents (e.g., rats, mice, hamsters and rabbits) , including transgenic rodents genetically engineered to produce human antibodies.

Human and humanized antibodies include antibodies having variable and constant regions derived from (or having the same amino acid sequence as those derived from) human germline immunoglobulin sequences. Human antibodies may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo) , for example in the CDRs.

A humanized antibody, typically has a human framework (FR) grafted with non-human CDRs. Thus, a humanized antibody has one or more amino acid sequence introduced into it from a source which is non-human. These non-human amino acid residues are often referred to as “import” residues, which are typically taken from an “import” variable domain. Humanization can be essentially performed by e.g., substituting rodent CDRs or CDR sequences for the corresponding sequences of a human antibody. These methods are described in e.g., Jones et al. "Replacing the complementarity-determining regions in a human antibody with those from a mouse. " Nature 321.6069 (1986) : 522; Riechmann et al. "Reshaping human antibodies for therapy. " Nature 332.6162 (1988) : 323; Dall'Acqua et al. "Antibody humanization by framework shuffling. " Methods 36.1 (2005) : 43-60; each of which is incorporated by reference herein in its entirety. Accordingly, “humanized” antibodies are chimeric antibodies wherein substantially less than an intact human V domain has been substituted by the corresponding sequence from a non-human species. In practice, humanized antibodies are typically mouse antibodies in which some CDR residues and some FR residues are substituted by residues from analogous sites in human antibodies.

The choice of human VH and VL domains to be used in making the humanized antibodies is very important for reducing immunogenicity. According to the so-called “best-fit” method, the sequence of the V domain of a mouse antibody is screened against the entire library of known human-domain sequences. The human sequence which is closest to that of the mouse is then accepted as the human FR for the humanized antibody (Sims et al. "A humanized CD 18 antibody can block function without cell destruction. " The Journal of Immunology 151.4 (1993) : 2296-2308; Chothia, et al., "Canonical structures for the hypervariable regions of immunoglobulins. " Journal of molecular biology 196.4 (1987) : 901-917) .

It is further important that antibodies be humanized with retention of high specificity and affinity for the antigen and other favorable biological properties. To achieve this goal, humanized antibodies can be prepared by a process of analysis of the parental sequences and various conceptual humanized products using three-dimensional models of the parental and humanized sequences. Three-dimensional immunoglobulin models are commonly available and are familiar to those skilled in the art. Computer programs are available which illustrate and display probable three-dimensional conformational structures of selected candidate immunoglobulin sequences. Inspection of these displays permits analysis of the likely role of the residues in the functioning of the candidate immunoglobulin sequence, i.e., the analysis of residues that influence the ability of the candidate immunoglobulin to bind its antigen. In this way, FR residues can be selected and combined from the recipient and import sequences so that the desired antibody characteristic, such as increased affinity for the target antigen (s) , is achieved.

Ordinarily, amino acid sequence variants of the human, humanized, or chimeric antibody will contain an amino acid sequence having at least 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99%percent identity with a sequence present in the light or heavy chain of the original antibody.

Identity or homology with respect to an original sequence is usually the percentage of amino acid residues present within the candidate sequence that are identical with a sequence present within the human, humanized, or chimeric antibody or fragment, after aligning the sequences and introducing gaps, ifnecessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity.

Additional modifications to the antibodies or antigen-binding fragments can be made. For example, a cysteine residue (s) can be introduced into the Fc region, thereby allowing interchain disulfide bond formation in this region. The homodimeric antibody thus generated may have any increased half-life in vitro and/or in vivo. Homodimeric antibodies with increased half-life in vitro and/or in vivo can also be prepared using heterobifunctional cross-linkers as described, for example, in Wolff et al. Wolff et al. ( "Monoclonal antibody homodimers: enhanced antitumor activity in nude mice. " Cancer research 53.11 (1993) : 2560-2565) . Alternatively, an antibody can be engineered which has dual Fc regions.

In some embodiments, a covalent modification can be made to the antibody or antigen-binding fragment thereof. These covalent modifications can be made by chemical or enzymatic synthesis, or by enzymatic or chemical cleavage. Other types of covalent modifications of the antibody or antibody fragment are introduced into the molecule by reacting targeted amino acid residues of the antibody or fragment with an organic derivatization agent that is capable of reacting with selected side chains or the N-or C-terminal residues.

In some embodiments, antibody variants are provided having a carbohydrate structure that lacks fucose attached (directly or indirectly) to an Fc region. For example, the amount of fucose in such antibody composition may be from 1%to 80%, from 1%to 65%, from 5%to 65%or from 20%to 40%. The amount of fucose is determined by calculating the average amount of fucose within the sugar chain at Ash297, relative to the sum of all glycostructures attached to Asn 297 (e.g. complex, hybrid and high mannose structures) as measured by MALDI-TOF mass spectrometry, as described in WO 2008/077546, for example. Asn297 refers to the asparagine residue located at about position 297 in the Fc region (Eu numbering of Fc region residues; or position 314 in Kabat numbering) ; however, Asn297 may also be located about ±3 amino acids upstream or downstream of position 297, i.e., between positions 294 and 300, due to minor sequence variations in antibodies. Such fucosylation variants may have improved ADCC function. In some embodiments, to reduce glycan heterogeneity, the Fc region of the antibody can be further engineered to replace the Asparagine at position 297 with Alanine (N297A) .

In some embodiments, to facilitate production efficiency by avoiding Fab-arm exchange, the Fc region of the antibodies was further engineered to replace the serine at position 228 (EU numbering) of IgG4 with proline (S228P) . A detailed description regarding S228 mutation is described, e.g., in Silva et al. "The S228P mutation prevents in vivo and in vitro IgG4 Fab-arm exchange as demonstrated using a combination of novel quantitative immunoassays and physiological matrix preparation. " Journal of Biological Chemistry 290.9 (2015) : 5462-5469, which is incorporated by reference in its entirety.

Recombinant Vectors

The present disclosure also provides recombinant vectors (e.g., an expression vectors) that include an isolated polynucleotide disclosed herein (e.g., a polynucleotide that encodes a polypeptide disclosed herein) , host cells into which are introduced the recombinant vectors (i.e., such that the host cells contain the polynucleotide and/or a vector comprising the polynucleotide) , and the production of recombinant antibody polypeptides or fragments thereof by recombinant techniques.

As used herein, a “vector” is any construct capable of delivering one or more polynucleotide (s) of interest to a host cell when the vector is introduced to the host cell. An “expression vector” is capable of delivering and expressing the one or more polynucleotide (s) of interest as an encoded polypeptide in a host cell into which the expression vector has been introduced. Thus, in an expression vector, the polynucleotide of interest is positioned for expression in the vector by being operably linked with regulatory elements such as a promoter, enhancer, and/or a poly-Atail, either within the vector or in the genome of the host cell at or near or flanking the integration site of the polynucleotide of interest such that the polynucleotide of interest will be translated in the host cell introduced with the expression vector.

A vector can be introduced into the host cell by methods known in the art, e.g., electroporation, chemical transfection (e.g., DEAE-dextran) , transformation, transfection, and infection and/or transduction (e.g., with recombinant virus) . Thus, non-limiting examples of vectors include viral vectors (which can be used to generate recombinant virus) , naked DNA or RNA, plasmids, cosmids, phage vectors, and DNA or RNA expression vectors associated with cationic condensing agents.

In some implementations, a polynucleotide disclosed herein (e.g., a polynucleotide that encodes a polypeptide disclosed herein) is introduced using a viral expression system (e.g., vaccinia or other pox virus, retrovirus, or adenovirus) , which may involve the use of a non-pathogenic (defective) , replication competent virus, or may use a replication defective virus. In the latter case, viral propagation generally will occur only in complementing virus packaging cells. Suitable systems are disclosed, for example, in Fisher-Hoch et al., 1989, Proc. Natl. Acad. Sci. USA 86: 317-321; Flexner et al., 1989, Ann. N.Y. Acad Sci. 569: 86-103; Flexner et al., 1990, Vaccine, 8: 17-21; U.S. Pat. Nos. 4,603,112, 4,769,330, and 5,017,487; WO 89/01973; U.S. Pat. No. 4,777,127; GB 2,200,651; EP 0,345,242; WO 91/02805; Berkner-Biotechniques, 6: 616-627, 1988; Rosenfeld et al., 1991, Science, 252: 431-434; Kolls et al., 1994, Proc. Natl. Acad. Sci. USA, 91: 215-219; Kass-Eisler et al., 1993, Proc. Natl. Acad. Sci. USA, 90: 11498-11502; Guzman et al., 1993, Circulation, 88: 2838-2848; and Guzman et al., 1993, Cir. Res., 73: 1202-1207. Techniques for incorporating DNA into such expression systems are well known to those of ordinary skill in the art. The DNA may also be “naked, ” as described, for example, in Ulmer et al., 1993, Science, 259: 1745-1749, and Cohen, 1993, Science, 259: 1691-1692. The uptake of naked DNA may be increased by coating the DNA onto biodegradable beads that are efficiently transported into the cells.

For expression, the DNA insert comprising an antibody-encoding or polypeptide-encoding polynucleotide disclosed herein can be operatively linked to an appropriate promoter (e.g., a heterologous promoter) , such as the phage lambda PL promoter, the E. coli lac, trp and tac promoters, the SV40 early and late promoters and promoters of retroviral LTRs, to name a few. Other suitable promoters are known to the skilled artisan. In some embodiments, the promoter is a cytomegalovirus (CMV) promoter. The expression constructs can further contain sites for transcription initiation, termination and, in the transcribed region, a ribosome binding site for translation. The coding portion of the mature transcripts expressed by the constructs may include a translation initiating at the beginning and a termination codon (UAA, UGA, or UAG) appropriately positioned at the end of the polypeptide to be translated.

As indicated, the expression vectors can include at least one selectable marker. Such markers include dihydrofolate reductase or neomycin resistance for eukaryotic cell culture and tetracycline or ampicillin resistance genes for culturing in E. coli and other bacteria. Representative examples of appropriate hosts include, but are not limited to, bacterial cells, such as E. coli, Streptomyces, and Salmonella typhimurium cells; fungal cells, such as yeast cells; insect cells such as Drosophila S2 and Spodoptera Sf9 cells; animal cells such as CHO, COS, Bowes melanoma, and HK 293 cells; and plant cells. Appropriate culture mediums and conditions for the host cells described herein are known in the art.

Non-limiting vectors for use in bacteria include pQE70, pQE60 and pQE-9, available from Qiagen; pBS vectors, Phagescript vectors, Bluescript vectors, pNH8A, pNH16a, pNH18A, pNH46A, available from Stratagene; and ptrc99a, pKK223-3, pKK233-3, pDR540, pRIT5 available from Pharmacia. Non-limiting eukaryotic vectors include pWLNEO, pSV2CAT, pOG44, pXT1 and pSG available from Stratagene; and pSVK3, pBPV, pMSG and pSVL available from Pharmacia. Other suitable vectors will be readily apparent to the skilled artisan.

Non-limiting bacterial promoters suitable for use include the E. coli lacI and lacZ promoters, the T3 and T7 promoters, the gpt promoter, the lambda PR and PL promoters and the trp promoter. Suitable eukaryotic promoters include the CMV immediate early promoter, the HSV thymidine kinase promoter, the early and late SV40 promoters, the promoters of retroviral LTRs, such as those of the Rous sarcoma virus (RSV) , and metallothionein promoters, such as the mouse metallothionein-I promoter.

In the yeast Saccharomyces cerevisiae, a number of vectors containing constitutive or inducible promoters such as alpha factor, alcohol oxidase, and PGH can be used.

Introduction of the construct into the host cell can be effected by calcium phosphate transfection, DEAE-dextran mediated transfection, cationic lipid-mediated transfection, electroporation, transduction, infection or other methods. Such methods are described in many standard laboratory manuals, such as Davis et al., Basic Methods in Molecular Biology (1986) , which is incorporated herein by reference in its entirety.

Transcription of DNA encoding an antibody of the present disclosure by higher eukaryotes may be increased by inserting an enhancer sequence into the vector. Enhancers are cis-acting elements of DNA, usually about from 10 to 300 bp that act to increase transcriptional activity of a promoter in a given host cell-type. Examples of enhancers include the SV40 enhancer, which is located on the late side of the replication origin at base pairs 100 to 270, the cytomegalovirus early promoter enhancer, the polyoma enhancer on the late side of the replication origin, and adenovirus enhancers.

For secretion of the translated protein into the lumen of the endoplasmic reticulum, into the periplasmic space or into the extracellular environment, appropriate secretion signals may be incorporated into the expressed polypeptide. The signals may be endogenous to the polypeptide or they may be heterologous signals.

The polypeptide (e.g., antibody) can be expressed in a modified form, such as a fusion protein (e.g., a GST-fusion) or with a histidine-tag, and may include not only secretion signals, but also additional heterologous functional regions. For instance, a region of additional amino acids, particularly charged amino acids, may be added to the N-terminus of the polypeptide to improve stability and persistence in the host cell, during purification, or during subsequent handling and storage. Also, peptide moieties can be added to the polypeptide to facilitate purification. Such regions can be removed prior to final preparation of the polypeptide. The addition ofpeptide moieties to polypeptides to engender secretion or excretion, to improve stability and to facilitate purification, among others, are familiar and routine techniques in the art.

Methods of Treatment

The antibodies or antigen-binding fragments thereof of the present disclosure can be used for various therapeutic purposes.

As used herein, the terms “treat, ” “treatment” and “treating” refer to the reduction or amelioration of the progression, severity, and/or duration of a disease (e.g., virus infection, or an upper and/or lower respiratory tract virus infection) , or a symptom or condition (e.g., fever, headache, cough, sore throat, difficulty breathing or vomiting) associated with the disease. In some embodiments, such terms refer to the reduction or inhibition of the replication of the virus, the inhibition or reduction in the spread of the virus to other tissues or subjects (e.g., the spread to the lower respiratory tract) , the inhibition or reduction of infection of a cell with a virus, or the amelioration of one or more symptoms associated with the virus (e.g., an upper and/or lower respiratory tract NiV infection or otitis media) .

As used herein, the terms “prevent, ” “preventing, ” and “prevention” refer to the prevention or inhibition of the development or onset of a disease (e.g., virus infection, or an upper and/or lower respiratory tract virus infection or a respiratory condition related thereto) in a subject, or reducing the likelihood of developing a disease.

Due to their binding to/interaction with the F protein (e.g., NiV-F or HeV-F) and/or G protein (e.g., NiV-G or HeV-G) , the antibodies or antigen-binding fragments thereof as described herein are useful for preventing fusion of the virus with the host cell membrane, for preventing cell to cell virus spread, and for inhibition of syncytia formation. As such, the antibodies or antigen-binding fragments thereof as described herein are useful for preventing an infection of a subject with Paramyxoviridae virus or Henipavirus (e.g., Hendra virus or Nipah virus) when administered prophylactically. In addition, the antibodies or antigen-binding fragments thereof as described herein can be useful for ameliorating at least one symptom associated with the virus infection, such as coughing, fever, pneumonia, or for lessening the severity, duration, and/or frequency of the infection. The antibodies or antigen-binding fragments thereof as described herein are also contemplated for prophylactic use in patients at risk for developing or acquiring a virus infection. These patients include pre-term infants, the elderly (for example, in anyone 65 years of age or older) , or patients immunocompromised due to illness or treatment with immunosuppressive therapeutics, or patients who may have an underlying medical condition that predisposes them to a virus infection. It is contemplated that the antibodies or antigen-binding fragments thereof as described herein can be used alone, or in conjunction with a second agent (e.g., an anti-G protein antibody or antigen binding fragment thereof) , or a third agent for treating virus infection, or for alleviating at least one symptom or complication associated with the infection, such as the fever, coughing, bronchiolitis, or pneumonia associated with, or resulting from such an infection. The second or third agents can be delivered concurrently with the antibodies of the invention, or they may be administered separately, either before or after the antibodies or antigen binding fragment thereof as described herein. The second or third agent can be an anti-viral such as ribavirin, an NSAID or other agents to reduce fever or pain, an antibody that specifically binds virus, an agent (e.g. an antibody) that binds to another antigen, such as G protein, a vaccine against the virus, an siRNA specific for a virus protein.

In some embodiments, the antibodies or antigen binding fragments thereof as described herein are more effective at neutralization of Paramyxoviridae virus or Henipavirus (e.g., Hendra virus or Nipah virus) compared to some known antibodies (e.g., 5B3) . Thus, in some embodiments, the antibodies or antigen binding fragments thereof as described herein with lower doses can have a greater level of protection against infection with Paramyxoviridae virus or Henipavirus (e.g., Hendra virus or Nipah virus) , and more effective treatment and/or amelioration of symptoms associated with the virus infection. The use of lower doses of antibodies or fragments thereof which immunospecifically bind to the antigen can result in fewer or less severe adverse events. Likewise, the use of more effective neutralizing antibodies can result in a diminished need for frequent administration of the antibodies or antibody fragments than previously envisioned as necessary for the prevention of infection, or for virus neutralization, or for treatment or amelioration of one or more symptoms associated with the virus infection. In addition, such antibodies or antigen binding fragments thereof can be useful when administered prophylactically (prior to exposure to the virus and infection with the virus) to lessen the severity, or duration of a primary infection with Paramyxoviridae virus or Henipavirus (e.g., Hendra virus or Nipah virus) , or ameliorate at least one symptom associated with the infection.

In some embodiments, the antibodies or antigen binding fragment thereof as described herein can be used for the preparation or manufacturing of a pharmaceutical composition for treating patients suffering from a virus infection (e.g., Paramyxoviridae virus or Henipavirus such as Hendra virus or Nipah virus) . In some embodiments, the antibodies or antigen binding fragment thereof as described herein can be used for the preparation of a pharmaceutical composition for reducing the severity of a primary infection with the virus, or for reducing the duration of the infection, or for reducing at least one symptom associated with the virus infection. In some embodiments, the antibodies or antigen binding fragment thereof as described herein can be used as adjunct therapy with any other agent useful for treating a virus infection, including an antiviral, a toxoid, a vaccine, a second anti-F protein or anti-G protein antibody, or any other antibody specific for a virus antigen, or any other palliative therapy known to those skilled in the art.

Thus, in one aspect, the disclosure provides methods for treating the virus infection in a subject, methods of reducing the rate of virus replication in a subject over time, methods of reducing the risk of being hospitalized or death, or methods of reducing the risk of infecting another subject. In some embodiments, the treatment can halt, slow, retard, or inhibit progression of the disease. In some embodiments, the treatment can result in the reduction of in the number, severity, and/or duration of one or more symptoms of the virus infection in a subject. In some embodiments, the virus infection is Paramyxoviridae virus infection or Henipavirus (e.g., Hendra virus or Nipah virus) infection.

In one aspect, the disclosure provides methods for treating, preventing, or reducing the risk of developing symptoms or disorders associated with virus infection.

As used herein, by an “effective amount” is meant an amount or dosage sufficient to effect beneficial or desired results including halting, slowing, retarding, or inhibiting progression of a disease, e.g., a virus infection. An effective amount will vary depending upon, e.g., an age and a body weight of a subject to which the antibody, antigen binding fragment, antibody-encoding polynucleotide, vector comprising the polynucleotide, and/or compositions thereof is to be administered, a severity of symptoms and a route of administration, and thus administration can be determined on an individual basis. An effective amount can be administered in one or more administrations. By way of example, an effective amount of an antibody or an antigen binding fragment is an amount sufficient to ameliorate, stop, stabilize, reverse, inhibit, slow and/or delay progression of virus infection in a patient. As is understood in the art, an effective amount of an antibody or antigen binding fragment may vary, depending on, inter alia, patient history as well as other factors such as the type (and/or dosage) of antibody used.

Effective amounts and schedules for administering the antibodies, antibody-encoding polynucleotides, and/or compositions disclosed herein may be determined empirically, and making such determinations is within the skill in the art. Those skilled in the art will understand that the dosage that must be administered will vary depending on, for example, the mammal that will receive the antibodies, antibody-encoding polynucleotides, and/or compositions disclosed herein, the route of administration, the particular type of antibodies, antibody-encoding polynucleotides, antigen binding fragments, and/or compositions disclosed herein used and other drags being administered to the mammal.

A typical daily dosage of an effective amount of an antibody is 0.01 mg/kg to 100 mg/kg (mg per kg of patient weight) . In some embodiments, the dosage can be less than 100 mg/kg, 50 mg/kg, 40 mg/kg, 30 mg/kg, 20 mg/kg, 10 mg/kg, 9 mg/kg, 8 mg/kg, 7 mg/kg, 6 mg/kg, 5 mg/kg, 4 mg/kg, 3 mg/kg, 2 mg/kg, 1 mg/kg, 0.5 mg/kg, or 0.1 mg/kg. In some embodiments, the dosage can be greater than 50 mg/kg, 40 mg/kg, 30 mg/kg, 20 mg/kg, 10 mg/kg, 9 mg/kg, 8 mg/kg, 7 mg/kg, 6 mg/kg, 5 mg/kg, 4 mg/kg, 3 mg/kg, 2 mg/kg, 1 mg/kg, 0.5 mg/kg, 0.1 mg/kg, 0.05 mg/kg, or 0.01 mg/kg. In some embodiments, the dosage is about 50 mg/kg, 40 rmg/kg, 30 mg/kg, 20 mg/kg, 10 mg/kg, 10 mg/kg, 9 rmg/kg, 8 mg/kg, 7 mg/kg, 6 mg/kg, 5 mg/kg, 4 mg/kg, 3 mg/kg, 2 mg/kg, or 1 mg/kg.

In any of the methods described herein, the at least one antibody, antigen-binding fragment thereof, or pharmaceutical composition (e.g., any of the antibodies, antigen-binding fragments, or pharmaceutical compositions described herein) and, optionally, at least one additional therapeutic agent can be administered to the subject at least once a week (e.g., once a week, twice a week, three times a week, four times a week, once a day, twice a day, or three times a day) . In some embodiments, at least two different antibodies and/or antigen-binding fragments are administered in the same composition (e.g., a liquid composition) . In some embodiments, at least one antibody or antigen-binding fragment and at least one additional therapeutic agent are administered in the same composition (e.g., a liquid composition) . In some embodiments, the at least one antibody or antigen-binding fragment and the at least one additional therapeutic agent are administered in two different compositions (e.g., a liquid composition containing at least one antibody or antigen-binding fragment and a solid oral composition containing at least one additional therapeutic agent) . In some embodiments, the at least one additional therapeutic agent is administered as a pill, tablet, or capsule. In some embodiments, the at least one additional therapeutic agent is administered in a sustained-release oral formulation.

In some embodiments, the one or more additional therapeutic agents can be administered to the subject prior to, or after administering the at least one antibody, antigen-binding antibody fragment, or pharmaceutical composition (e.g., any of the antibodies, antigen-binding antibody fragments, or pharmaceutical compositions described herein) . In some embodiments, the one or more additional therapeutic agents and the at least one antibody, antigen-binding antibody fragment, or pharmaceutical composition (e.g., any of the antibodies, antigen-binding antibody fragments, or pharmaceutical compositions described herein) are administered to the subject such that there is an overlap in the bioactive period of the one or more additional therapeutic agents and the at least one antibody or antigen-binding fragment (e.g., any of the antibodies or antigen-binding fragments described herein) in the subject.

In some embodiments, the subject can be administered the at least one antibody, antigen-binding antibody fragment, or pharmaceutical composition (e.g., any of the antibodies, antigen-binding antibody fragments, or pharmaceutical compositions described herein) over an extended period of time (e.g., over a period of at least 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 1 year, 2 years, 3 years, 4 years, or 5 years) . A skilled medical professional may determine the length of the treatment period using any of the methods described herein for diagnosing or following the effectiveness of treatment (e.g., the observation of at least one symptom of virus infection) . As described herein, a skilled medical professional can also change the identity and number (e.g., increase or decrease) of antibodies or antigen-binding antibody fragments (and/or one or more additional therapeutic agents) administered to the subject and can also adjust (e.g., increase or decrease) the dosage or frequency of administration of at least one antibody or antigen-binding antibody fragment (and/or one or more additional therapeutic agents) to the subject based on an assessment of the effectiveness of the treatment (e.g., using any of the methods described herein and known in the art) .

In some embodiments, the additional therapeutic agent is an antiviral agent, a toxoid, a vaccine, a second anti-F protein or anti-G protein antibody, or any other antibody specific for a virus antigen, an antibiotics, an agent for ameliorating symptoms, or any other palliative therapy known to those skilled in the art.

Pharmaceutical Compositions and Routes of Administration

Also provided herein are pharmaceutical compositions that contain at least one (e.g., one, two, three, or four) of the antibodies or antigen-binding fragments described herein. Two or more (e.g., two, three, or four) of any of the antibodies or antigen-binding fragments described herein can be present in a pharmaceutical composition in any combination. The pharmaceutical compositions may be formulated in any manner known in the art.

Pharmaceutical compositions are formulated to be compatible with their intended route of administration (e.g., intravenous, intraarterial, intramuscular, intradermal, subcutaneous, or intraperitoneal) . The compositions can include a sterile diluent (e.g., sterile water or saline) , a fixed oil, polyethylene glycol, glycerine, propylene glycol or other synthetic solvents, antibacterial or antifungal agents, such as benzyl alcohol or methyl parabens, chlorobutanol, phenol, ascorbic acid, thimerosal, and the like, antioxidants, such as ascorbic acid or sodium bisulfite, chelating agents, such as ethylenediaminetetraacetic acid, buffers, such as acetates, citrates, or phosphates, and isotonic agents, such as sugars (e.g., dextrose) , polyalcohols (e.g., mannitol or sorbitol) , or salts (e.g., sodium chloride) , or any combination thereof. Liposomal suspensions can also be used as pharmaceutically acceptable carriers. Preparations of the compositions can be formulated and enclosed in ampules, disposable syringes, or multiple dose vials. Where required (as in, for example, injectable formulations) , proper fluidity can be maintained by, for example, the use of a coating, such as lecithin, or a surfactant. Absorption of the antibody or antigen-binding fragment thereof can be prolonged by including an agent that delays absorption (e.g., aluminum monostearate and gelatin) . Alternatively, controlled release can be achieved by implants and microencapsulated delivery systems, which can include biodegradable, biocompatible polymers (e.g., ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid) .

Compositions containing one or more of any of the antibodies or antigen-binding fragments described herein can be formulated for parenteral (e.g., intravenous, intraarterial, intramuscular, intradermal, subcutaneous, or intraperitoneal) administration in dosage unit form (i.e., physically discrete units containing a predetermined quantity of active compound for ease of administration and uniformity of dosage) .

Pharmaceutical compositions for parenteral administration are preferably sterile and substantially isotonic and manufactured under Good Manufacturing Practice (GMP) conditions. Pharmaceutical compositions can be provided in unit dosage form (i.e., the dosage for a single administration) . Pharmaceutical compositions can be formulated using one or more physiologically acceptable carriers, diluents, excipients or auxiliaries. The formulation depends on the route of administration chosen. For injection, antibodies can be formulated in aqueous solutions, preferably in physiologically-compatible buffers to reduce discomfort at the site of injection. The solution can contain formulatory agents such as suspending, stabilizing and/or dispersing agents. Alternatively antibodies can be in lyophilized form for constitution with a suitable vehicle, e.g., sterile pyrogen-free water, before use.

Toxicity and therapeutic efficacy of compositions can be determined by standard pharmaceutical procedures in cell cultures or experimental animals (e.g., monkeys) . One can, for example, determine the LD50 (the dose lethal to 50%of the population) and the ED50 (the dose therapeutically effective in 50%of the population) : the therapeutic index being the ratio of LD50: ED50. Agents that exhibit high therapeutic indices are preferred. Where an agent exhibits an undesirable side effect, care should be taken to minimize potential damage (i.e., reduce unwanted side effects) . Toxicity and therapeutic efficacy can be determined by other standard pharmaceutical procedures.

Data obtained from cell culture assays and animal studies can be used in formulating an appropriate dosage of any given agent for use in a subject (e.g., a human) . A therapeutically effective amount of the one or more (e.g., one, two, three, or four) antibodies or antigen-binding fragments thereof (e.g., any of the antibodies or antibody fragments described herein) will be an amount that treats the disease in a subject (e.g., virus infection) in a subject (e.g., a human subject identified as having virus infection) , or a subject identified as being at risk of developing the disease (e.g., a subject at high risk of acquiring a virus infection) , decreases the severity, frequency, and/or duration of one or more symptoms of a disease in a subject (e.g., a human) . The effectiveness and dosing of any of the antibodies or antigen-binding fragments described herein can be determined by a health care professional or veterinary professional using methods known in the art, as well as by the observation of one or more symptoms of disease in a subject (e.g., a human) . Certain factors may influence the dosage and timing required to effectively treat a subject (e.g., the severity of the disease or disorder, previous treatments, the general health and/or age of the subject, and the presence of other diseases) .

Exemplary doses include milligram or microgram amounts of any of the antibodies or antigen-binding fragments described herein per kilogram of the subject's weight (e.g., about 1 μg/kg to about 500 mg/kg; about 100 μg/kg to about 500 mg/kg; about 100 μg/kg to about 50 mg/kg; about 10 μg/kg to about 5 mg/kg; about 10 μg/kg to about 0.5 mg/kg; about 1 μg/kg to about 50 μg/kg; about 1 mg/kg to about 50 mg/kg; about 10 mg/kg to about 50 mg/kg; about 10 mg/kg to about 40 mg/kg; or about 1 mg/kg to about 5 mg/kg) . While these doses cover a broad range, one of ordinary skill in the art will understand that therapeutic agents, including antibodies and antigen-binding fragments thereof, vary in their potency, and effective amounts can be determined by methods known in the art. Typically, relatively low doses are administered at first, and the attending health care professional or veterinary professional (in the case of therapeutic application) or a researcher (when still working at the development stage) can subsequently and gradually increase the dose until an appropriate response is obtained. In addition, it is understood that the specific dose level for any particular subject will depend upon a variety of factors including the activity of the specific compound employed, the age, body weight, general health, gender, and diet of the subject, the time of administration, the route of administration, the rate of excretion, and the half-life of the antibody or antibody fragment in vivo.

The pharmaceutical compositions can be included in a container, pack, or dispenser together with instructions for administration. The disclosure also provides methods of manufacturing the antibodies or antigen binding fragments thereof for various uses as described herein.

Diagnostic Uses

The anti-F protein or anti-G protein antibodies or antigen binding fragments thereof as described herein can also be used to detect and/or measure Paramyxoviridae virus or Henipavirus (e.g., Hendra virus or Nipah virus) in a sample, e.g., for diagnostic purposes. The virus infection can be determined by the presence of the virus through use of any one or more of the anti-F protein or anti-G protein antibodies or antigen binding fragments thereof as described herein. In some embodiments, the methods can involve, e.g., contacting a sample, obtained from a patient, with an anti-F protein and/or anti-G protein antibodies or antigen binding fragments thereof as described herein, wherein the anti-F protein and/or anti-G protein antibodies or antigen binding fragments thereof is labeled with a detectable label or reporter molecule or used as a capture ligand to selectively isolate the virus containing the F protein and/or G protein from patient samples. In some embodiments, an unlabeled anti-F protein or anti-G protein antibody or antigen binding fragment thereof can be used in diagnostic applications in combination with a secondary antibody which is itself detectably labeled. The detectable label or reporter molecule can be a radioisotope, a fluorescent or chemiluminescent moiety such as fluorescein isothiocyanate, or rhodamine, or an enzyme such as alkaline phosphatase, β-galactosidase, horseradish peroxidase, or luciferase. Specific exemplary assays that can be used to detect or measure virus containing the F protein or G protein in a sample include enzyme-linked immunosorbent assay (ELISA) , radioimmunoassay (RIA) , and fluorescence-activated cell sorting (FACS) .

Samples that can be used in virus diagnostic assays include e.g., any tissue or fluid sample obtainable from a patient, which contains detectable quantities of F protein and/or G protein, or fragments thereof, under normal or pathological conditions. Generally, levels of F protein or G protein in a particular sample obtained from a healthy patient (e.g., a patient not afflicted with a disease or condition associated with the presence of F protein or G protein) will be measured to initially establish a baseline. This baseline level of F protein or G protein can then be compared against the levels of F protein or G protein measured in samples obtained from individuals suspected of having a virus infection, or symptoms associated with such infection.

EXAMPLES

The invention is further described in the following examples, which do not limit the scope of the invention described in the claims.

Example 1. Generating Mouse Anti-F Protein and Anti-G Protein Antibodies

The anti-F protein and anti-G protein antibodies were collected by the methods as described below. To generate mouse antibodies against F protein or G protein, 6-8 weeks old female BALB/c mice were immunized with Nipah virus F protein (Niv-F or F; SEQ ID NO: 71) or Nipah virus G protein (Niv-G or G; SEQ ID NO: 88) . Anti-F protein or anti-G protein antibodies were collected by the methods as described below and shown in FIG. 1 and FIG. 2.

Immunization of mice

6-8 weeks old female BALB/c mice were immunized with His-tagged NiV-F proteins or G proteins at 20 μg/mouse at a concentration of 100 μg/ml. The His-tagged NiV-F proteins or G proteins were emulsified with adjuvant and injected at four positions on the back of the mice. For the first subcutaneous (s. c. ) injection, the diluted antigen was emulsified with Complete Freund's Adjuvant (CFA) in equal volume. In the following subcutaneous injections, the protein was emulsified with Incomplete Freund's Adjuvant (IFA) in equal volume. Three days after the third injection or the booster immunization, blood (serum) was collected and analyzed for antibody titer using Fluorescence-Activated Cell Sorting (FACS) .

In another experiment, 6-8 weeks old female BALB/c mice were immunized by injecting the expression plasmid encoding NiV-F protein or G protein into the mice. The plasmids encoding the antigen were injected into the tibialis anterior muscle (intramuscular injection; i. m. injection) of the mice by using gene guns at the concentration of 1000 μg/ul at 60 μg per mouse. At least four injections were performed with at least 14 days between two injections. Blood (serum) was collected seven days after the last immunization and the serum was tested for antibody titer by FACS.

Procedures to enhance immunization were also performed at least fourteen days after the previous immunization (either by injecting the plasmid or by injecting the proteins) . Chinese hamster ovary (CHO) cells expressing F proteins or G proteins were intravenously injected into the mice through tail veins. Spleen was then collected four days after the injection.

Fusion of SP2/0 cells and spleen cells

Spleen tissues were grinded. Spleen cells were first selected by CD3e Microbeads and Anti-Mouse IgM Microbeads, and then fused with SP2/0 cells. The cells were then plated in 96-well plates with hypoxanthine-aminopterin-thymidine (HAT) medium.

Primary screening of hybridoma

Primary screening of the hybridoma supematant in the 96-well plates was performed using FACS pursuant to standard procedures. CHO cells were added to 96-well plates (2 × 10 ⁴ cells per well) before the screening. 50 μl of supematant was used. The antibody used in experiments was Fluorescein (FITC) -conjugated AffiniPure F (ab) ₂ Fragment Goat Anti-Mouse IgG, Fcγ Fragment Specific.

Sub-cloning

Sub-cloning was performed using ClonePix2. In short, the positive wells identified during the primary screening were transferred to semisolid medium, and IgG positive clones were identified and tested. FITC labeled anti-mouse IgG Fc antibody was used.

Ascites fluid antibodies

1 × 10 ⁶ positive hybridoma cells were injected intraperitoneally to

mice (Biocytogen Pharmaceuticals (Beijing) , Beijing, China; Catalog number: B-CM-002) . Monoclonal antibodies were produced by growing hybridoma cells within the peritoneal cavity of the mouse. The hybridoma cells multiplied and produced ascites fluid in the abdomens of the mice. The fluid contained a high concentration of antibody which was harvested for later use.

Purification of antibodies

Antibodies in ascites fluid were purified using GE AKTA protein chromatography (GE Healthcare, Chicago, Illinois, United States) . At least 10 murine antibodies were produced. A few antibodies were selected because of the desired properties. These selected murine antibodies produced by the methods described above including e.g., 03-3C9 ( “3C9” ) , 09-3G8 ( “3G8” ) , 09-5C10 ( “5C10” ) , 07-4D6 ( “4D6” ) , 09-4D2 ( “4D2” ) , 09-1E6 ( “1E6” ) , 01-2H5 ( “2H5” ) , 05-4H8 ( “4H8” ) , 09-1H10 ( “1H10” ) , 03-2F6 ( “2F6” ) , NiG-3D8 ( “3D8” ) , NiG-1G9 ( “1G9” ) , etc.

The VH, VL and CDR regions for some of the antibodies were determined. The heavy chain CDR1, CDR2, CDR3, and light chain CDR1, CDR2, and CDR3 amino acid sequences of 2F6, 3C9, 4H8, 3D8 and 1G9 are shown in FIG. 3 (Kabat numbering) or FIG. 4 (Chothia numbering) .

Example 2. Generating Chimeric Anti-F Protein and Anti-G Protein antibodies

Chimeric antibodies were constructed with the variable region of mouse antibody and the constant domain of human IgG1. The amino acid sequences for the heavy chain variable region (VH) and the light chain variable region (VL) of mouse antibodies 2F6, 3C9, 4H8, 3D8 and 1G9 were determined.

2F6-mHvKv-hIgG1 is a chimeric antibody having the heavy chain variable region (SEQ ID NO: 61) and the light chain variable region (SEQ ID NO: 62) of mouse antibody 2F6, each connected with human IgG1 constant domains.

3C9-mHvKv-hIgG1 is another chimeric antibody having the heavy chain variable region (SEQ ID NO: 63) and the light chain variable region (SEQ ID NO: 64) of mouse antibody 3C9.

4H8-mHvKv-hIgG1 is a chimeric antibody having the heavy chain variable region (SEQ ID NO: 65) and the light chain variable region (SEQ ID NO: 66) of mouse antibody 4H8.

NiG-3D8-mHvKv-hIgG1 is a chimeric antibody having the heavy chain variable region (SEQ ID NO: 67) and the light chain variable region (SEQ ID NO: 68) of mouse antibody 3D8.

NiG-1G9-mHvKv-hIgG1 is a chimeric antibody having the heavy chain variable region (SEQ ID NO: 69) and the light chain variable region (SEQ ID NO: 70) of mouse antibody 1G9.

The VH and VL amino acid sequences of these antibodies are shown in FIG. 5.

Chimeric antibodies are also purified using GE AKTA protein chromatography (GE Healthcare, Chicago, Illinois, United States) .

Example 3. Humanization of Mouse Anti-F Protein and Anti-G Protein Antibodies

The starting point for humanization is the mouse antibodies (e.g., 3C9) . The amino acid sequences for the heavy chain variable region and the light chain variable region of these mouse antibodies are determined.

Humanized heavy chain variable region variants and humanized light chain variable region variants are constructed, containing different modifications or substitutions.

These humanized heavy chain variable region variants can be combined with any of the light chain variable region variants derived from the same mouse antibody.

Each humanized heavy chain variable region variant can be connected with a human heavy chain constant region to generate a complete humanized antibody heavy chain, and each humanized light chain variable region variant can be connected with a human light chain constant region to generate a complete humanized antibody light chain. Mutations can also be introduced within the constant regions of the antibody.

Example 4. EC50 determination for neutralizing Nipah and Hendra pseudovirus

Nipah Pseudovirus Neutralization Assay

Vectors encoding the NiV-F proteins or NiV-G proteins from 6 NiV strains were used. Specifically, the NiV strains and the corresponding full-length NiV-F proteins or NiV-G proteins are as follows:

(1) AF212302.2, Nipah virus ( “NiV-M1” ) having a NiV-F protein with the amino acid sequence of SEQ ID NO: 71 and a NiV-G protein with the amino acid sequence of SEQ ID NO: 88;

(2) F J513078.1, Nipah virus isolate Ind-Nipah-07-FG from India ( “NiV-IN1” ) having a NiV-F protein with the amino acid sequence of SEQ ID NO: 72 and a NiV-G protein with the amino acid sequence of SEQ ID NO: 89;

(3) MH396625.1, Nipah henipavirus strain MCL-18-H-1088 ( “NiV-IN2” ) , having a NiV-F protein with the amino acid sequence of SEQ ID NO: 73 and a NiV-G protein with the amino acid sequence of SEQ ID NO: 90;

(4) JN808864.1, Nipah virus isolate NIVBGD2010FARIDPUR ( “NiV-B 1” ) , having a NiV-F protein with the amino acid sequence of SEQ ID NO: 74 and a NiV-G protein with the amino acid sequence of SEQ ID NO: 91;

(5) JN808863.1, Nipah virus isolate NIVBGD2008RAJBARI ( “NiV-B3” ) , having a NiV-F protein with the amino acid sequence of SEQ ID NO: 75 and a NiV-G protein with the amino acid sequence of SEQ ID NO: 92;

(6) MK801755.1, Nipah henipavirus isolate C SUR381 ( “NiV-C1” ) , having a NiV-F protein with the amino acid sequence of SEQ ID NO: 76 and a NiV-G protein with the amino acid sequence of SEQ ID NO: 93.

The sequence alignment of F proteins from NiV-M1, NiV-IN1, NiV-IN2, NiV-B 1 and NiV-B3 are shown in FIG. 6. As shown in FIG. 6, these NiV-F proteins are not identical. The difference in certain amino acid residues may impact the binding of the antibodies to NiV-F proteins. Thus, it is advantageous if an antibody can bind to NiV-F proteins from different strains with high affinities.

The sequence alignment of G proteins from NiV-M1, NiV-IN1, NiV-IN2, NiV-B 1 and NiV-B3 are shown in FIG. 11. As shown in FIG. 11, these NiV-G proteins are not identical. The difference in certain amino acid residues may impact the binding of the antibodies to NiV-G proteins. Thus, it is advantageous if an antibody can bind to NiV-G proteins from different strains with high affinities.

Purified chimeric anti-F protein or anti-G antibodies were subject to serial dilution in a 96-well plate. Then, the Nipah Pseudovirus was diluted to 1-2 × 10 ⁴ TCID ₅₀/ml and mixed with the antibodies. Next, 100μL Vero cells (5 × 10 ⁵ cells/well) were added to the corresponding wells, and the plate was incubated at 37℃, 5%CO ₂ for 48 hours. After the incubation, 100 μl supernatant was discarded by pipetting, and 100 μl luciferase detection reagent was added to each well. The plate was then incubated at room temperature in dark for 2 minutes. Afterwards, 150 μl solution in each well was transferred to a new plate, which was placed in a plate reader to measure chemiluminescence signals. The neutralization inhibition ratio was calculated as follows:

Inhibition rate = [1- (Ab-CC) / (VC-CC) ] × 100%

wherein Ab is the average signal of the antibody wells; CC is the average signal of the cell control wells (culture medium only) ; VC is the average signal of the virus control wells (culture medium with the recombinant NiV virus added) . According to the inhibition rate, EC50 can be calculated by the Reed-Muench algorithm. Details of this method can be found, e.g., in Reed et al. “A simple method of estimating fifty per cent endpoints. ” American Journal of Epidemiology 27.3 (1938) : 493-497; which is incorporated herein by reference in the entirety. The EC50 of anti-F protein or anti-G protein antibodies were determined and the results are listed in the table below.

Table 1

Hendra Pseudovirus Neutralization Assay

Vectors encoding HeV-F proteins or HeV-G proteins from 7 HeV strains were used. Specifically, the HeV strains and the corresponding full-length HeV-F proteins and HeV-G proteins are as follows:

(1) HeV-A2 having a HeV-F protein with the amino acid sequence of SEQ ID NO: 77 and a HeV-G protein with the amino acid sequence of SEQ ID NO: 94;

(2) HeV-A3 having a HeV-F protein with the amino acid sequence of SEQ ID NO: 78 and a HeV-G protein with the amino acid sequence of SEQ ID NO: 95;

(3) HeV-A4 having a HeV-F protein with the amino acid sequence of SEQ ID NO: 79 and a HeV-G protein with the amino acid sequence of SEQ ID NO: 96;

(4) HeV-A5 having a HeV-F protein with the amino acid sequence of SEQ ID NO: 80 and a HeV-G protein with the amino acid sequence of SEQ ID NO: 97;

(5) HeV-A6 having a HeV-F protein with the amino acid sequence of SEQ ID NO: 81 and a HeV-G protein with the amino acid sequence of SEQ ID NO: 98;

(6) HeV-A7 having a HeV-F protein with the amino acid sequence of SEQ ID NO: 82 and a HeV-G protein with the amino acid sequence of SEQ ID NO: 99;

(7) HeV-A8 having a HeV-F protein with the amino acid sequence of SEQ ID NO: 83 and a HeV-G protein with the amino acid sequence of SEQ ID NO: 100.

The sequence alignment ofFF proteins from HeV-A2, HeV-A3, HeV-A4, HeV-A5, HeV-A6, HeV-A7 and HeV-A8 are shown in FIG. 7. As shown in FIG. 7, these HeV-F proteins are not identical. The difference in certain amino acid residues may impact the binding of the antibodies to HeV-F proteins. Thus, it is advantageous if an antibody can bind to HeV-F proteins from different strains with high affinities.

The sequence alignment of G proteins from HeV-A2, HeV-A3, HeV-A4, HeV-A5, HeV-A6, HeV-A7 and HeV-A8 are shown in FIG. 12. As shown in FIG. 12, these HeV-G proteins are not identical. The difference in certain amino acid residues may impact the binding of the antibodies to HeV-G proteins. Thus, it is advantageous if an antibody can bind to HeV-G proteins from different strains with high affinities.

Chimeric anti-F protein or anti-G protein antibodies were serial diluted in a 96-well plate. Then, the Hendra Pseudovirus was diluted to 1-2 × 10 ⁴ TCID ₅₀/ml and mixed with the antibodies. Next, 100μL Vero cells (5 × 10 ⁵ cells/well) were added to the corresponding wells, and the plate was incubated at 37℃, 5%CO ₂ for 48 hours. After the incubation, 100 μl supernatant was discarded by pipetting, and 100 μl luciferase detection reagent was added to each well. The plate was then incubated at room temperature in dark for 2 minutes. Afterwards, 150 μl solution in each well was transferred to a new plate, which was placed in a plate reader to measure chemiluminescence signals. The neutralization inhibition ratio was calculated as follows:

Inhibition rate = [1- (Ab-CC) / (VC-CC) ] × 100%

wherein Ab is the average signal of the antibody wells; CC is the average signal of the cell control wells (culture medium only) ; VC is the average signal of the virus control wells (culture medium with the recombinant NiV virus added) . According to the inhibition rate, EC50 can be calculated by the Reed-Muench algorithm. The EC50 of anti-F protein or anti-G protein antibodies were determined and the results are listed in the table below.

Table 2

ND: Not Detected

The results showed that 3C9-mHvKv-hIgG1 and 2F6-mHvKv-hIgG1 can both neutralize multiple strains of HeV virus. 3C9-mHvKv-hIgG1 showed a better neutralization effect comparing to 2F6-mHvKv-hIgG1.

Based on the above results, we analyzed the EC50 against NiV-M1 and HeV-A2 for antibodies including 2F 6-mHvKv-hIgG1, 3 C9-mHvKv-hIgG1, m 102.3 and m5B 3. The results are shown in Table 3 below, m5B3 is a monoclonal antibody targeting the F glycoprotein of Hendra virus and Nipah virus, with a VH sequence of SEQ ID NO: 84 and a VL sequence of SEQ ID NO: 85 (see PCT/US2015/012641) . m102.3 is a monoclonal antibody targeting the G glycoprotein of Hendra virus and Nipah virus, with a VH sequence of SEQ ID NO: 86 and a VL sequence of SEQ ID NO: 87 (see US 2015/0071854A1) .

Table 3

As shown in Table 3, all four antibodies can neutralize both NiV-M1 and HeV-A2. 3C9-mHvKv-hIgG1 showed a better neutralization effect comparing to m 102.3 and m5B3.

Example 5. Anti-F Protien Antibody Epitope Binding by BLI Assay

NiV virus Affinity

The interaction of the anti-F protein antibodies to recombinant His-tagged NiV-F protein was measured by Biolayer Interferometry (BLI) using ForteBio Octet system at 30℃. A total of 10 monoclonal antibodies were used: 3C9-mHvkV-IgG1, 3G8-mHvKv-IgG1, 5C10-mHvKv-IgG1, 4D6-mHvKv-IgG1, 4D2-mHvKv-IgG1, 1E6-mHvKv-IgG1, 2H5-mHvKv-IgG1, 4H8-mHvKv-IgG1, 1H10-mHvKv-IgG1 and 2F6-mHvKv-IgG1.

Anti-F protein antibodies were loaded onto AHC biosensor (ForteBio, 18-5060) at 10 ug/mL to yield a response of 1.0nm. Kinetic measurements were performed at the concentrations 12.5 nM, 25 nM, 50 nM, 100 nM, 200 nM, and 400 nM of the recombinant His-tagged NiV-F protein. The association phase lasted for 150 s and the dissociation phase 300 s followed by a regeneration step with 10 mM Glycine-HCl, pH1.5. Data analysis was performed using the Octet data analysis program (DataAnalysis11) and a standard 1: 1 binding model. Affinity values were deduced from the quotient of the kinetic rate constants (KD=koff/kon) .

As a person of ordinary skill in the art would understand, the same method with appropriate adjustments for parameters (e.g., antibody concentration) was performed for each tested antibody. The results for the tested antibodies are summarized in the table below.

Table 4

Antibody	KD (M)	kon (1/Ms)	koff (1/s)
3C9-mHvkV-IgG1	4.97E-09	8.38E+04	4.17E-04
3G8-mHvKv-IgG1	5.21E-09	6.46E+04	3.36E-04
5C10-mHvKv-IgG1	6.94E-09	5.82E+04	4.04E-04
4D6-mHvKv-IgG1	9.72E-09	4.50E+04	4.37E-04

4D2-mHvKv-IgG1	1.28E-08	3.78E+04	4.83E-04
1E6-mHvKv-IgG1	1.09E-08	4.62E+04	5.02E-04
2H5-mHvKv-IgG1	1.27E-08	4.48E+04	5.71E-04
4H8-mHvKv-IgG1	8.82E-09	5.39E+04	4.76E-04
1H10-mHvKv-IgG1	2.48E-08	2.63E+04	6.51E-04
2F6-mHvKv-IgG1	8.11E-09	6.40E+04	5.19E-04

To further characterize the binding epitopes, anti-F protein antibodies were tested for their binding reactivity to NiV-F protein. Anti-F protein antibodies at concentrations of 200 nM were used. The results are shown in FIG. 8.

The numeric values in FIG. 8 represent the inhibition rate calculated from the below formula: Inhibition rate = Rc/R0, where Rc represents the amount of Ab2 captured by Ab1, and R0 represents the amount of Ab2 not captured by Ab1. FIG. 10 is a visual presentation of this formula, where Ag represents the antigen and the Y axis represents signal intensity (unit: nm) . A closer to 100%inhibition rate means that the two antibodies recognize very different regions in the antigen. A closer to 0 inhibition rate means that the two antibodies recognize very similar regions in the antigen. Sometimes the inhibition rate may have a negative value due to non-specific binding.

In binding characterization, 3C9-mHvkV-IgG1 and 2F6-mHvKv-IgG1 bind with high affinity to NiV-F protein as measured by BLI (KD are 4.97× 10 ^-9 M and 8.11 × 10 ^-9 M respectively) . The epitope binding assay results suggest that 3C9-mHvkV-IgG1 and 2F6-mHvKv-IgG1 recognize same epitope.

HeV virus Affinity

The interaction of the anti-F protein antibodies to recombinant His-tagged HeV-F protein was measured by Biolayer Interferometry (BLI) using the ForteBio Octet system at 30℃. A total of 10 monoclonal antibodies were used: 3C9-mHvkV-IgG1, 3G8-mHvKv-IgG1, 5C10-mHvKv-IgG1, 4D6-mHvKv-IgG1, 4D2-mHvKv-IgG1, 1E6-mHvKv-IgG1, 2H5-mHvKv-IgG1, 4H8-mHvKv-IgG1, 1H10-mHvKv-IgG1 and 2F6-mHvKv-IgG1.

Anti-F protein antibodies were loaded onto AHC biosensor (ForteBio, 18-5060) at 10 ug/mL to yield a response of 1.0nm. Kinetic measurements were performed at the concentrations 12.5 nM, 25 nM, 50 nM, 100 nM, 200 nM, and 400 nM of the recombinant His-tagged HeV-F protein. The association phase lasted for 150 s and the dissociation phase 300 s followed by a regeneration step with 10 mM Glycine-HCl, pH1.5. Data analysis was performed using the Octet data analysis program (DataAnalysis11) and a standard 1: 1 binding model. Affinity values were deduced from the quotient of the kinetic rate constants (KD=koff/kon) .

Table 5

Antibody	KD (M)	kon (1/Ms)	koff (1/s)
3C9-mHvkV-IgG1	3.85E-09	7.80E+04	3.00E-04
3G8-mHvKv-IgG1	1.51E-08	8.35E+04	1.26E-03
5C10-mHvKv-IgG1	1.87E-08	8.46E+04	1.58E-03
4D6-mHvKv-IgG1	2.60E-08	4.09E+04	1.06E-03
4D2-mHvKv-IgG1	2.14E-08	4.29E+04	9.18E-04
1E6-mHvKv-IgG1	1.85E-08	7.55E+04	1.40E-03
2H5-mHvKv-IgG1	2.71E-08	5.03E+04	1.37E-03
4H8-mHvKv-IgG1	2.96E-08	7.86E+04	2.33E-03
1H10-mHvKv-IgG1	2.67E-08	5.43E+04	1.45E-03
2F6-mHvKv-IgG1	6.30E-09	7.72E+04	4.87E-04

To further characterize the binding epitopes, anti-F protein antibodies were tested for their binding reactivity to HeV-F protein. The results are shown in FIG. 9.

In a different experiment, anti-F protein antibodies at concentrations of 200 nM were used. Similar to the experiment results regarding NiV virus, in binding characterization, 3C9-mHvkV-IgG1 and 2F6-mHvKv-IgG1 bind with high affinity to HeV-F protein as measured by BLI (KD are 3.85 × 10 ^-9 M and 6.30 × 10 ^-9 M respectively) . The epitope binning as say results suggest that 3C9-mHvkV-IgG1 and 2F6-mHvKv-IgG1 recognize the same epitope.

Example 6. In vivo testing of antibodies

Experimental animals:

Twenty female ferrets weighing 0.75-1 kg are selected, 4 in each group.

Preventive effects:

The animals are divided into 2 groups, the administration group and the negative control group. The anti-F protein or anti-G protein antibody is administered to the ferret by intraperitoneal administration at a dose of 20 mg/kg on the day before exposure to the virus. The negative control group is given an equal volume of phosphate buffered saline (PBS) .

On day 0, 5× 10 ³ PFU of Nipah recombinant virus or Hendra recombinant virus are administered intranasally. From day 1, the weight and body temperature of the ferret are measured, and the health status of the ferret is recorded (observed for at least 10 days) . 4 animals are sacrificed on day 5 (2 in each group) , and lung tissue and trachea tissue are collected for pathology analysis. At the same time, the viral load in the trachea and the lungs is analyzed by PCR.

Treatment effects:

The animals are divided into 3 groups: 2 administration groups and 1 negative control group. On day 0, 5× 10 ³ PFU of Nipah recombinant virus or Hendra recombinant virus are administered intranasally. On day 1, the anti-F protein or anti-G protein antibody is administered to the ferret by intraperitoneal administration at doses of 20 mg/kg for the first administration group and 30 mg/kg for the second administration group. The negative control group is given an equal volume of PBS. From day 1, the weight and body temperature of the ferret are measured, and the health status of the ferret is recorded (observed for 10 days) . 4 animals are sacrificed on day 5 (2 in each group) , and lung tissue and trachea tissue are collected for pathology analysis. At the same time, the viral load in the trachea and the lungs is analyzed by PCR.

OTHER EMBODIMENTS

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.

Claims

An anti-F protein antibody or antigen-binding fragment thereof, comprising:

a heavy chain variable region (VH) comprising complementarity determining regions (CDRs) 1, 2, and 3, wherein the VH CDR1 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR1 amino acid sequence, the VH CDR2 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR2 amino acid sequence, and the VH CDR3 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR3 amino acid sequence; and

a light chain variable region (VL) comprising CDRs 1, 2, and 3, wherein the VL CDR1 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR1 amino acid sequence, the VL CDR2 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR2 amino acid sequence, and the VL CDR3 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR3 amino acid sequence,

wherein the selected VH CDRs 1, 2, and 3 amino acid sequences and the selected VL CDRs, 1, 2, and 3 amino acid sequences are one of the following:

(1) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 1, 2, 3, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 4, 5, 6, respectively;

(2) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 7, 8, 9, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 10, 11, 12, respectively;

(3) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 13, 14, 15, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 16, 17, 18, respectively.

(4) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 19, 20, 21, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 22, 23, 24, respectively;

(5) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 25, 26, 27, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 28, 29, 30, respectively; or

(6) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 31, 32, 33, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 34, 35, 36, respectively.
An anti-G protein antibody or antigen-binding fragment thereof, comprising:

a heavy chain variable region (VH) comprising complementarity determining regions (CDRs) 1, 2, and 3, wherein the VH CDR1 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR1 amino acid sequence, the VH CDR2 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR2 amino acid sequence, and the VH CDR3 region comprises an amino acid sequence that is at least 80%identical to a selected VH CDR3 amino acid sequence; and

a light chain variable region (VL) comprising CDRs 1, 2, and 3, wherein the VL CDR1 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR1 amino acid sequence, the VL CDR2 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR2 amino acid sequence, and the VL CDR3 region comprises an amino acid sequence that is at least 80%identical to a selected VL CDR3 amino acid sequence,

wherein the selected VH CDRs 1, 2, and 3 amino acid sequences and the selected VL CDRs, 1, 2, and 3 amino acid sequences are one of the following:

(1) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 37, 38, 39, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 40, 41, 42, respectively.

(2) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 43, 44, 45, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 46, 47, 48, respectively;

(3) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 49, 50, 51, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 52, 53, 54, respectively; or

(4) the selected VH CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 55, 56, 57, respectively, and the selected VL CDRs 1, 2, 3 amino acid sequences are set forth in SEQ ID NOs: 58, 59, 60, respectively.
The antibody or antigen-binding fragment thereof of claim 1, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 1, 2, and 3 respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively according to Kabat numbering scheme.
The antibody or antigen-binding fragment thereof of claim 1, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 7, 8, and 9, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 10, 11, and 12, respectively according to Chothia numbering scheme.
The antibody or antigen-binding fragment thereof of claim 1, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 13, 14, and 15, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 16, 17, and 18, respectively according to Kabat numbering scheme.
The antibody or antigen-binding fragment thereof of claim 1, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 19, 20, and 21, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 22, 23, and 24, respectively according to Chothia numbering scheme.
The antibody or antigen-binding fragment thereof of claim 1, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 25, 26, and 27, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 28, 29, and 30, respectively according to Kabat numbering scheme.
The antibody or antigen-binding fragment thereof of claim 1, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 31, 32, and 33, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 34, 35, and 36, respectively according to Chothia numbering scheme.
The antibody or antigen-binding fragment thereof of claim 2, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 37, 38, and 39, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 40, 41, and 42, respectively according to Kabat numbering scheme.
The antibody or antigen-binding fragment thereof of claim 2, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 43, 44, and 45, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 46, 47, and 48, respectively according to Chothia numbering scheme.
The antibody or antigen-binding fragment thereof of claim 2, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 49, 50, and 51, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 52, 53, and 54, respectively according to Kabat numbering scheme.
The antibody or antigen-binding fragment thereof of claim 2, wherein the VH comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 55, 56, and 57, respectively, and the VL comprises CDRs 1, 2, 3 with the amino acid sequences set forth in SEQ ID NOs: 58, 59, and 60, respectively according to Chothia numbering scheme.
The antibody or antigen-binding fragment thereof of any one of claims 1 and 3-8, wherein the antibody or antigen-binding fragment specifically binds to Nipah virus F protein and/or Hendra virus F protein.
The antibody or antigen-binding fragment thereof of any one of claims 2 and 9-12, wherein the antibody or antigen-binding fragment specifically binds to Nipah virus G protein and/or Hendra virus G protein.
The antibody or antigen-binding fragment thereof of any one of claims 1-14, wherein the antibody or antigen-binding fragment is a humanized antibody or antigen-binding fragment thereof (e.g., a human IgG1 antibody) .
The antibody or antigen-binding fragment thereof of any one of claims 1-15, wherein the antibody or antigen-binding fragment is a single-chain variable fragment (scFV) .
A nucleic acid comprising a polynucleotide encoding a polypeptide comprising:

(1) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising complementarity determining regions (CDRs) 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 1, 2, and 3, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 62 binds to F protein;

(2) an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 61 binds to F protein;

(3) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 13, 14 and 15, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 64 binds to F protein;

(4) an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 16, 17 and 18, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 63 binds to F protein;

(5) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 25, 26 and 27, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 66 binds to F protein; or

(6) an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 28, 29 and 30, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 65 binds to F protein.
A nucleic acid comprising a polynucleotide encoding a polypeptide comprising:

(1) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 37, 38 and 39, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 68 binds to G protein;

(2) an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 40, 41 and 42, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 67 binds to G protein;

(3) an immunoglobulin heavy chain or a fragment thereof comprising a heavy chain variable region (VH) comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 49, 50 and 51, respectively, and wherein the VH, when paired with a light chain variable region (VL) comprising the amino acid sequence set forth in SEQ ID NO: 70 binds to G protein; or

(4) an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 52, 53 and 54, respectively, and wherein the VL, when paired with a VH comprising the amino acid sequence set forth in SEQ ID NO: 69 binds to G protein.
The nucleic acid of claim 17, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or a fragment thereof comprising a VH comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 1, 2, and 3, respectively.
The nucleic acid of claim 17, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 4, 5, and 6, respectively.
The nucleic acid of claim 17, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or a fragment thereof comprising a VH comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 13, 14 and 15, respectively.
The nucleic acid of claim 17, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 16, 17 and 18, respectively.
The nucleic acid of claim 17, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or a fragment thereof comprising a VH comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 25, 26 and 27, respectively.
The nucleic acid of claim 17, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 28, 29 and 30, respectively.
The nucleic acid of claim 18, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or a fragment thereof comprising a VH comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 37, 38 and 39, respectively.
The nucleic acid of claim 18, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 40, 41 and 42, respectively.
The nucleic acid of claim 18, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin heavy chain or a fragment thereof comprising a VH comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 49, 50 and 51, respectively.
The nucleic acid of claim 18, wherein the nucleic acid comprises a polynucleotide encoding a polypeptide comprising an immunoglobulin light chain or a fragment thereof comprising a VL comprising CDRs 1, 2, and 3 comprising the amino acid sequences set forth in SEQ ID NOs: 52, 53 and 54, respectively.
The nucleic acid of any one of claims 17 and 19-24, wherein the VH when paired with a VL specifically binds to Nipah virus F protein and/or Hendra virus F protein, or the VL when paired with a VH specifically binds to Nipah virus F protein and/or Hendra virus F protein.
The nucleic acid of any one of claims 18 and 25-28, wherein the VH when paired with a VL specifically binds to Nipah virus G protein and/or Hendra virus G protein, or the VL when paired with a VH specifically binds to Nipah virus G protein and/or Hendra virus G protein.
The nucleic acid of any one of claims 17-30, wherein the immunoglobulin heavy chain or the fragment thereof is a humanized immunoglobulin heavy chain or a fragment thereof, and the immunoglobulin light chain or the fragment thereof is a humanized immunoglobulin light chain or a fragment thereof.
The nucleic acid of any one of claims 17-31, wherein the nucleic acid encodes a single-chain variable fragment (scFv) .
The nucleic acid of any one of claims 17-32, wherein the nucleic acid is cDNA.
A vector comprising one or more of the nucleic acids of any one of claims 17-33.
A vector comprising two of the nucleic acids of any one of claims 17 and 19-24, wherein the vector encodes the VH region and the VL region that together bind to a F protein.
A pair of vectors, wherein each vector comprises one of the nucleic acids of any one of claims 17 and 19-24, wherein together the pair of vectors encodes the VH region and the VL region that together bind to a F protein.
A vector comprising two of the nucleic acids of any one of claims 18 and 25-28, wherein the vector encodes the VH region and the VL region that together bind to a G protein.
A pair of vectors, wherein each vector comprises one of the nucleic acids of any one of claims 18 and 25-28, wherein together the pair of vectors encodes the VH region and the VL region that together bind to a G protein.
A cell comprising the vector of claim 34, 35 or 37, or the pair of vectors of claim 36 or 38.
The cell of claim 39, wherein the cell is a CHO cell.
A cell comprising one or more of the nucleic acids of any one of claims 17-33.
A cell comprising two of the nucleic acids of any one of claims 17-33.
The cell of claim 42, wherein the two nucleic acids together encode the VH region and the VL region that together bind to a F protein or a G protein.
A method of producing an antibody or an antigen-binding fragment thereof, the method comprising

(a) culturing the cell of any one of claims 39-43 under conditions sufficient for the cell to produce the antibody or the antigen-binding fragment; and

(b) collecting the antibody or the antigen-binding fragment produced by the cell.
An anti-F protein antibody or antigen-binding fragment thereof comprising

a heavy chain variable region (VH) comprising an amino acid sequence that is at least 80%identical to a selected VH sequence, and a light chain variable region (VL) comprising an amino acid sequence that is at least 80%identical to a selected VL sequence, wherein the selected VH sequence and the selected VL sequence are one of the following:

(1) the selected VH sequence is SEQ ID NO: 61, and the selected VL sequence is SEQ ID NO: 62;

(2) the selected VH sequence is SEQ ID NO: 63, and the selected VL sequence is SEQ ID NO: 64; or

(3) the selected VH sequence is SEQ ID NO: 65, and the selected VL sequence is SEQ ID NO: 66.
An anti-G protein antibody or antigen-binding fragment thereof comprising

a heavy chain variable region (VH) comprising an amino acid sequence that is at least 80%identical to a selected VH sequence, and a light chain variable region (VL) comprising an amino acid sequence that is at least 80%identical to a selected VL sequence, wherein the selected VH sequence and the selected VL sequence are one of the following:

(1) the selected VH sequence is SEQ ID NO: 67, and the selected VL sequence is SEQ ID NO: 68; or

(2) the selected VH sequence is SEQ ID NO: 69, and the selected VL sequence is SEQ ID NO: 70.
The antibody or antigen-binding fragment thereof of claim 45, wherein the VH comprises the sequence of SEQ ID NO: 61 and the VL comprises the sequence of SEQ ID NO: 62.
The antibody or antigen-binding fragment thereof of claim 45, wherein the VH comprises the sequence of SEQ ID NO: 63 and the VL comprises the sequence of SEQ ID NO: 64.
The antibody or antigen-binding fragment thereof of claim 45, wherein the VH comprises the sequence of SEQ ID NO: 65 and the VL comprises the sequence of SEQ ID NO: 66.
The antibody or antigen-binding fragment thereof of claim 46, wherein the VH comprises the sequence of SEQ ID NO: 67 and the VL comprises the sequence of SEQ ID NO: 68.
The antibody or antigen-binding fragment thereof of claim 46, wherein the VH comprises the sequence of SEQ ID NO: 69 and the VL comprises the sequence of SEQ ID NO: 70.
The antibody or antigen-binding fragment thereof of any one of claims 45 and 47-49, wherein the antibody or antigen-binding fragment specifically binds to Nipah virus F protein and/or Hendra virus F protein.
The antibody or antigen-binding fragment thereof of any one of claims 46, 50 and 51, wherein the antibody or antigen-binding fragment specifically binds to Nipah virus G protein and/or Hendra virus G protein.
The antibody or antigen-binding fragment thereof of any one of claims 45-53, wherein the antibody or antigen-binding fragment is a humanized antibody or antigen-binding fragment thereof.
The antibody or antigen-binding fragment thereof of any one of claims 45-54, wherein the antibody or antigen-binding fragment is a single-chain variable fragment (scFV) .
An antibody-drug conjugate comprising the antibody or antigen-binding fragment thereof of any one of claims 1-16 and 45-55 covalently bound to a therapeutic agent.
An antibody or antigen-binding fragment thereof that cross-competes with the antibody or antigen-binding fragment thereof of any one of claims 1-16 and 45-55.
An antibody or antigen-binding fragment thereof comprising:

a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 61; and

a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 62.
An antibody or antigen-binding fragment thereof comprising:

a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 63; and

a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 64.
An antibody or antigen-binding fragment thereof comprising:

a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 65; and

a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 66.
An antibody or antigen-binding fragment thereof comprising:

a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 67; and

a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 68.
An antibody or antigen-binding fragment thereof comprising:

a heavy chain variable region (VH) comprising VH CDR1, VH CDR2, and VH CDR3 that are identical to VH CDR1, VH CDR2, and VH CDR3 of SEQ ID NO: 69; and

a light chain variable region (VL) comprising VL CDR1, VL CDR2, and VL CDR3 that are identical to VL CDR1, VL CDR2, and VL CDR3 of SEQ ID NO: 70.
A method for reducing the risk of Nipah virus (NiV) infection or treating NiV infection, or at least one symptom associated with the NiV infection in a subject, the method comprising administering a therapeutically effective amount of a composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1-16, 45-55 and 58-62, or the antibody-drug conjugate of claim 56, to the subject in need thereof.
The method of claim 63, wherein the subject has exposure to NiV, NiV infection, or at least one symptom associated with NiV infection.
The method of claim 63, wherein the at least one symptom associated with NiV infection is selected from the group consisting of fever, headache, cough, sore throat, difficulty breathing, vomiting, disorientation, drowsiness, confusion, seizures, coma and brain swelling (encephalitis) .
The method of claim 63, wherein the at least one symptom associated with NiV infection is fever, headache, cough, sore throat, difficulty breathing or vomiting.
A method for reducing the risk of Hendra virus (HeV) infection or treating HeV infection, or at least one symptom associated with HeV infection in a subject, the method comprising administering an effective amount of a composition comprising an antibody or antigen-binding fragment thereof of any one of claims 1-16, 45-55 and 58-62, or the antibody-drug conjugate of claim 56, to the subject in need thereof.
The method of claim 67, wherein the subject has exposure to HeV, HeV infection, or at least one symptom associated with HeV infection.
The method of claim 67, wherein the at least one symptom associated with HeV infection is selected from the group consisting of fever, headache, cough, sore throat, difficulty breathing, vomiting, disorientation, drowsiness, confusion, seizures, coma and brain swelling (encephalitis) .
The method of claim 67, wherein the at least one symptom associated with HeV infection is fever, headache, cough, sore throat, difficulty breathing or vomiting.
A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1-16, 45-55 and 58-62, and a pharmaceutically acceptable carrier.
A pharmaceutical composition comprising the antibody drug conjugate of claim 56, and a pharmaceutically acceptable carrier.