WO2021169167A1

WO2021169167A1 - Method for treating coronavirus infections

Info

Publication number: WO2021169167A1
Application number: PCT/CN2020/104579
Authority: WO
Inventors: Fangliang Zhang; Kening Li; Weiming Wang; Ming Zeng; Xian Zhang; Bo Wu; Pei Liu; Lidan DING; Lu Yang; Hui Chen; Yikai QIU; Liusong YIN; Wenshuang JIA; Zhongdao LI; Tongtong HU; Zirui ZHANG; Xijian QIN; Dongming Wu; Zhaoxia CHENG
Original assignee: Nanjing GenScript Biotech Co., Ltd.; Nanjing Legend Biotech Co., Ltd.
Priority date: 2020-02-29
Filing date: 2020-07-24
Publication date: 2021-09-02

Abstract

Provided are viral vectors for the prevention or treatment of COVID-19 infection, wherein the vector comprises a 5' inverted terminal repeat (ITR) of adeno-associated virus (AAV) and a 3' AAV ITR, a promoter, a restriction site downstream of the promoter to allow insertion of a polynucleotide encoding a SARS-CoV-2-neutralizing antibody or an ACE2-Fc fusion protein, and a post-transcriptional regulatory element downstream of the restriction site, wherein the promoter, the restriction site and the post-transcription regulatory element are located downstream of the 5' AAV ITR and upstream of the 3' AAV ITR. Also provided are methods of making the vectors, pharmaceutical compositions comprising the vectors, and methods of preventing or treating SARS-CoV-2 infection.

Description

Method for Treating Coronavirus Infections

RELATED APPLICATIONS AND INCORPORATION BY REFERENCE

This application claims priority to Chinese Patent Application No. CN202010132178.7 filed on February 29, 2020, Chinese Patent Application No. CN202010442784.9 filed on May 22, 2020, Chinese Patent Application No. CN202010451374.0 filed on May 25, 2020, Chinese Patent Application No. CN202010566590. X filed on June 19, 2020, International Patent Application No. PCT/CN2020/092748 filed on May 28, 2020, and International Patent Application No. PCT/CN2020/092934 filed on May 28, 2020.

The foregoing applications, and all documents cited therein or during their prosecution ( “appln cited documents” ) and all documents cited or referenced herein (including without limitation all literature documents, patents, published patent applications cited herein) ( “herein cited documents” ) , and all documents cited or referenced in herein cited documents, together with any manufacturer’s instructions, descriptions, product specifications, and product sheets for any products mentioned herein or in any document incorporated by reference herein, are hereby incorporated herein by reference, and may be employed in the practice of the invention. More specifically, all referenced documents are incorporated by reference to the same extent as if each individual document was specifically and individually indicated to be incorporated by reference. Any Genbank sequences mentioned in this disclosure are incorporated by reference with the Genbank sequence to be that of the earliest effective filing date of this disclosure.

Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.

FIELD OF THE INVENTION

The present disclosure relates to the treatment of viral infection by vector-mediated delivery of antibodies in vivo, including pharmaceutical compositions comprising the vectors, medicinal uses thereof and methods of treatment using the same.

BACKGROUND OF THE INVENTION

The outbreak of COVID-19, caused by the novel coronavirus SARS-Cov-2, has since spread around the globe, infecting millions of people and resulting in tens of thousands of deaths. To date, there is no vaccine, or antiviral medication for COVID-19. Existing treatment is directed at relieving symptoms and may include pain relievers, cough syrup or medication, rest, and fluid intake.

Ongoing research is studying various drugs that may be effective for treating severe COVID-19. For example, Remdesivir, a small antiviral molecule with a high genetic barrier to resistance in coronaviruses, displays potent in vitro activity against SARS-CoV-2, but its compassionate use is only considered for hospitalized patients with polymerase chain reaction (PCR) -confirmed SARS-CoV-2 requiring mechanical ventilation. Even though Remdesivir can be a promising agent for the treatment of COVID-19, we need to wait for trial results and safety data.

Chloroquine and hydroxychloroquine have anti-inflammatory and immunomodulatory activities, with potent in vitro activity of chloroquine against SARS-CoV-2, yet no efficacy data are available for hydroxychloroquine, and cardiovascular toxicity concerns limit the use of chloroquine.

Tocilizumab, a humanized monoclonal antibody that inhibits both membrane-bound and soluble interleukin-6 (IL-6) receptors and is being considered as a treatment option for severe or critical cases of COVID-19, with elevated IL-6 having hyper-inflammatory states and cytokine storming. Two ongoing trials in China are evaluating that safety and efficacy of this therapy; to date, no concerning adverse events have been reported yet.

Nitazoxanide has demonstrated potent in vitro activity against SARS-CoV-2. It interferes with host regulated pathways involved in viral replication, and is, hence, considered broad spectrum. More data are needed too to determine its role in the management of COVID-19.

Corticosteroids have also been used but their risks and benefits need to be carefully weighed on the individual patient level. Large-dose glucocorticoid suppresses the immune system and could delay clearance of SARS-CoV-2.

Convalescent plasma, though used previously for SARS-CoV-1, Middle East respiratory syndrome, Ebola virus disease, and H1N1 influenza with reported success, its safety and efficacy in SARS-CoV-2-infected patients has not been established yet and is still under study.

Despite tremendous efforts, no effective vaccine has been developed so far, and none is expected to be available, if at all, within the next 6 months.

Many newly identified SARS-Cov-2 neutralizing antibodies have been identified and are under or will be under trial for treating CoVid-19. However, using antibodies in the treatment or prevention of SARS-Cov-2 infections pose its own problems, including the development of anti-drug antibody (ADA) by the patient, and the need to repeatedly inject the antibody into the patients.

There is thus a need for novel methods of treatment of COVID-19.

SUMMARY OF THE INVENTION

This present disclosure provides in some embodiments a vector-mediated gene transfer, to express and deliver anti-COVID-19 antibodies into a subject in need thereof, e.g., directly into circulation.

Methods for producing therapeutic proteins in vivo have seen tremendous progress recently, and a clinical trial has shown that an adeno-associated virus (AAV) vector can be engineered to effectively deliver a broadly neutralizing antibody (bNAb) , VRC07, against HIV, without adverse event while achieving high antibody level in vivo at more than 1 year after injection of the vector. Only three of the eight trial participants developed antibodies against VRC07; it is not yet clear whether these anti-drug antibodies (ADA) could reduce VRC07’s ability to neutralize HIV (see e.g. JP Casazza et al. Durable HIV-1 antibody production in humans after AAV8-mediated gene transfer. Oral presentation at the 2020 Conference on Retroviruses and Opportunistic Infections. Presented March 9, 2020; U.S. Pat. No. 9,527,904) .

In one embodiment, the present disclosure provides a viral vector, where the viral vector comprises: a 5' inverted terminal repeat (ITR) of adeno-associated virus (AAV) and a 3' AAV ITR; a promoter; a restriction site downstream of the promoter to allow insertion of a polynucleotide encoding one or more proteins (in particular a SARS-CoV-2-neutralizing antibody or an ACE2-Fc fusion protein) of interest; and a post-transcriptional regulatory element downstream of the restriction site, where the promoter, the restriction site and the post-transcription regulatory element are located downstream of the 5' AAV ITR and upstream of the 3' AAV ITR.

In some embodiments, the viral vector further comprises a polynucleotide inserted at the restriction site and operably linked with the promoter, where the polynucleotide comprises a coding region of an antibody or a variant thereof, or a coding region of an ACE2-Fc fusion protein or a variant thereof.

In some embodiments, the polynucleotide comprises a signal peptide sequence immediately upstream of the coding region of the antibody or variant thereof, or the coding region of the ACE2-Fc fusion protein or a variant thereof. In some embodiments, the signal peptide is selected from the group consisting of a signal peptide of interferon, a signal peptide of human growth hormone, a signal peptide of erythropoietin (EPO) , a signal peptide of granulocyte colony-stimulating factor (G-CSF) , a signal peptide of insulin, and any combination thereof. In some embodiments, the signal peptide sequence comprises a nucleotide sequence having at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%sequence identity, or more to SEQ ID NOs: 11 or 12.

In some embodiments, the viral vector comprises a nucleotide sequence having at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%sequence identity, or more to the Kozak consensus sequence. In some embodiments, the viral vector comprises a nucleotide sequence having at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%sequence identity, or more to SEQ ID NOs: 32 or 33.

In some embodiments, the antibody or variant thereof is selected from the group consisting of full-length antibodies, antibody Fab fragments, antibody scFv fragments, a single chain antibody (sdAb) , bispecific Single-Domain Antibody fused to Monoclonal Antibody (SMAB, as disclosed in WO2018014855A1) , and any variant thereof.

In some embodiments, the antibody or variant thereof is a virus neutralizing antibody. In some embodiments, the virus neutralizing antibody is a neutralizing antibody against a SARS-CoV-2.

In some embodiments, the neutralizing antibody against SARS-CoV-2 is selected from the group consisting of an antibody that is disclosed in Examples 2-6 herein below, or any variant thereof.

In some embodiments, the ACE2-Fc fusion protein is the one disclosed in Example 1, or any variant thereof.

In some embodiments, the promoter comprises cytomegalovirus (CMV) immediate early promoter, chicken beta-actin (CAG) promoter, ubiquitin C (UBC) promoter, or any variant thereof.

In some embodiments, the promoter comprises a splice donor, a splice acceptor, or any variant thereof. In some embodiments, the splice donor comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to SEQ ID NO: 5. In some embodiments, the splice acceptor comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to SEQ ID NO: 6. In some embodiments, the promoter comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to SEQ ID NO: 1. In some embodiments, the promoter comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to any one of SEQ ID NOs: 2-4.

In some embodiments, the post-transcriptional regulatory element is a viral post-transcriptional regulatory element. In some embodiments, the viral post-transcriptional regulatory element is woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) , hepatitis B virus post-transcriptional regulatory element (HBVPRE) , RNA transport element (RTE) , or any variant thereof. In some embodiments, the post-transcriptional regulatory element of the disclosure comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to SEQ ID NO: 7.

In some embodiments, the viral vector further comprises a transcription termination region downstream of the post-transcriptional regulatory element. In some embodiments, the transcription termination region comprises an SV40 late poly (A) sequence, a rabbit beta-globin poly (A) sequence, a bovine growth hormone poly (A) sequence, or any variant thereof.

In some embodiments, the promoter comprises an intron. In some embodiments, the intron is a synthetic intron comprising a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to SEQ ID NO: 8.

In some embodiments, the polynucleotide comprises a first coding region for the heavy chain variable region of an immunoglobulin and a second coding region for the light chain variable region of the immunoglobulin. In some embodiments, the first coding region and the second coding region are separated by a 2A sequence. In some embodiments, the 2A sequence is an F2A sequence, comprising e.g., a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to SEQ ID NO: 9 or 10.

In some embodiments, 5' of the first coding region is fused with a first signal peptide sequence and 5' of the second coding region is fused with a second signal peptide sequence. In some embodiments, the first signal peptide sequence and the second signal peptide sequence are different.

In some embodiments, the region starting from the 5' ITR and ending at the 3' ITR is at least about 2.5 kb.

In some embodiments, the viral vector comprises a nucleotide sequence having at least 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99%sequence identity to any one of SEQ ID NOs: 13 to 31.

Some embodiments herein provide a method for producing an antibody or a variant thereof, or an ACE2-Fc fusion protein or a variant thereof, in vivo, where the method comprises: providing a recombinant adeno-associated virus (AAV) comprising a nucleotide sequence encoding the antibody or a variant thereof or an ACE2-Fc fusion protein or a variant thereof; and administering the recombinant AAV to the subject, whereby the recombinant AAV expresses the antibody or variant thereof, or an ACE2-Fc fusion protein or a variant thereof, in the subject, wherein the nucleotide is at least about 1.4 kb.

In some embodiments, the antibody is a full length antibody. In some embodiments, the antibody is selected from the group consisting of an antibody that is disclosed in Examples 2-6 hereinbelow and any variant thereof. In some embodiments, the ACE2-Fc fusion protein is the one disclosed in Example 1, or any variant thereof.

In some embodiments, the antibody or a variant thereof, or the ACE2 fusion protein or a variant thereof, is expressed in the serum of the subject in the amount of at least about 9 μg/ml. In some embodiments, the antibody or variant thereof, or the ACE2 fusion protein or a variant thereof, is expressed in the serum of the subject in the amount of at least about 100 μg/ml. In some embodiments, the antibody or variant thereof, or the ACE2 fusion protein or a variant thereof, is expressed in the serum of the subject in the amount of at least about 500 μg/ml.

In some embodiments, the recombinant AAV is produced by providing a packaging cell line with a viral vector, helper functions for generating a productive AAV infection, and AAV cap genes, where the viral vector comprises a 5' AAV inverted terminal repeat (ITR) , a 3' AAV ITR and a nucleotide sequence encoding the antibody or variant thereof, or the ACE2 fusion protein or variant thereof, ; and recovering a recombinant AAV virus from the supernatant of the packaging cell line.

In some embodiments, the viral vector is any one of viral vectors disclosed herein.

Some embodiments disclosed herein provide a method for reducing or inhibiting the infection risk of a virus in a subject, where the method comprises: providing a recombinant adeno-associated virus (AAV) comprising a nucleotide sequence encoding a neutralizing antibody or a variant thereof for the virus, or an ACE2 fusion protein or a variant thereof; and administering the recombinant AAV to the subject, whereby the recombinant AAV expresses the antibody or variant thereof, or the ACE2-Fc fusion protein or a variant thereof, in the subject.

In some embodiments, the method further comprises providing a second recombinant AAV comprising a nucleotide sequence encoding a second neutralizing antibody or a variant thereof for the virus.

In some embodiments, the subject is a mammal. In some embodiments, the subject is a human.

In some embodiments, the neutralizing antibody is a full-length antibody.

In some embodiments, the virus is SARS-CoV-2.

In some embodiments, the method reduces the infection risk in the subject by at least about 5 fold as compared to the subjects without the viral vector treatment. In some embodiments, the method reduces the infection risk in the subject by at least about 20 fold as compared to the subjects without the viral vector treatment. In some embodiments, the method inhibits the viral infection in the subject.

In some embodiments, the antibody or variant thereof, or the ACE2-Fc fusion protein or variant thereof, is expressed in the serum of the subject in the amount of at least about 9 μg/ml. In some embodiments, the antibody or variant thereof, or the ACE2-Fc fusion protein or variant thereof, is expressed in the serum of the subject in the amount of at least about 100 μg/ml. In some embodiments, the antibody or variant thereof, or the ACE2-Fc fusion protein or variant thereof, is expressed in the serum of the subject in the amount of at least about 500 μg/ml

In some embodiments, the neutralizing antibody is selected from the group consisting of an antibody that is disclosed in Examples 2-6 hereinbelow, and any variant thereof. In some embodiments, the ACE2-Fc fusion protein is the one disclosed in Example 1, or any variant thereof.

In some embodiments, the recombinant AAV is administered to the subject by intramuscular injection, intravaginal injection, intravenous injection, intraperitoneal injection, subcutaneous injection, epicutaneous administration, intradermal administration, or nasal administration.

In some embodiments, the recombinant AAV is administered to the subject at most once every year. In some embodiments, the recombinant AAV is administered to the subject at most once every 5 years. In some embodiments, the recombinant AAV is administered to the subject at most once every 10 years.

Some embodiments disclosed herein provide a method of producing a recombinant adeno-associated virus (AAV) of the disclosure, where the method comprises: providing a packaging cell line with a viral construct comprising 5' AAV inverted terminal repeat (ITR) and 3' AAV ITR, helper functions for generating a productive AAV infection, and AAV cap genes; and recovering a recombinant AAV virus from the supernatant of the packaging cell line.

In some embodiments, the AAV cap genes encode a capsid from serotype 1, serotype 2, serotype 4, serotype 5, serotype 6, serotype 7, serotype 8, serotype 9, or a variant thereof.

In some embodiments, the viral construct is any of the viral vectors disclosed herein.

In some embodiments, the recombinant AAV is not a self-complementary AAV (scAAV) .

Other features and advantages of the instant disclosure will be apparent from the following detailed description and examples, which should not be construed as limiting. The contents of all references, Genbank entries, patents and published patent applications cited throughout this application are expressly incorporated herein by reference.

Accordingly, it is an object of the invention not to encompass within the invention any previously known product, process of making the product, or method of using the product such that Applicants reserve the right and hereby disclose a disclaimer of any previously known product, process, or method. It is further noted that the invention does not intend to encompass within the scope of the invention any product, process, or making of the product or method of using the product, which does not meet the written description and enablement requirements of the USPTO (35 U.S.C. §112, first paragraph) or the EPO (Article 83 of the EPC) , such that Applicants reserve the right and hereby disclose a disclaimer of any previously described product, process of making the product, or method of using the product. It may be advantageous in the practice of the invention to be in compliance with Art. 53 (c) EPC and Rule 28 (b) and (c) EPC. All rights to explicitly disclaim any embodiments that are the subject of any granted patent (s) of applicant in the lineage of this application or in any other lineage or in any prior filed application of any third party is explicitly reserved. Nothing herein is to be construed as a promise.

It is noted that in this disclosure and particularly in the claims and/or paragraphs, terms such as "comprises" , "comprised" , "comprising" and the like can have the meaning attributed to it in U. S. Patent law; e.g., they can mean "includes" , "included" , "including" , and the like; and that terms such as "consisting essentially of" and "consists essentially of" have the meaning ascribed to them in U.S. Patent law, e.g., they allow for elements not explicitly recited, but exclude elements that are found in the prior art or that affect a basic or novel characteristic of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The illustrative embodiments described in the detailed description, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Examples, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

The present application provides viral vectors useful in producing recombinant adeno-associated viruses (AAVs) , and recombinant AAVs capable of expressing one or more antibodies or variants thereof in an appropriate environment, for example, in a cell, a tissue, an organ, or a subject transfected with the recombinant AAVs. Also disclosed herein are the methods for making and using the recombinant AAVs. For example, the recombinant AAVs can be used to produce an antibody or a variant thereof in vivo, ex vivo, or in vitro. In some embodiments, the expression of the antibody or variant thereof can be used to diagnose, prevent, treat, reduce or inhibit the risk of viral infections.

In some embodiments, the viral vector comprises a 5' inverted terminal repeat (ITR) of AAV and a 3' AAV ITR, a promoter, a restriction site downstream of the promoter to allow insertion of a polynucleotide encoding one or more antibodies or variants thereof, and a post-transcriptional regulatory element downstream of the restriction site, where the promoter, the restriction site and the post-transcription regulatory element are located downstream of the 5' AAV ITR and upstream of the 3' AAV ITR. The viral vector can be used, for example, to express one or more antibodies or variants thereof. For example, the viral vector can include a polynucleotide encoding one or more anti-SARS-CoV-2 antibodies. The viral vector can, for example, be used to produce high level of the antibody or variant thereof in a subject for diagnostic or therapeutic purposes.

Definitions

Unless defined otherwise, 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. See, e.g. Singleton et al., Dictionary of Microbiology and Molecular Biology 2nd ed., J. Wiley&Sons (New York, N.Y. 1994) ; Sambrook et al., Molecular Cloning, A Laboratory Manual, Cold Springs Harbor Press (Cold Springs Harbor, N.Y. 1989) . For purposes of the present disclosure, the following terms are defined below.

As used herein, the term "vector" refers to a polynucleotide construct, typically a plasmid or a virus, used to transmit genetic material to a host cell. Vectors can be, for example, viruses, plasmids, cosmids, or phages. A vector as used herein can be composed of either DNA or RNA. In some embodiments, a vector is composed of DNA. An "expression vector" is a vector that is capable of directing the expression of a protein encoded by one or more genes carried by the vector when it is present in the appropriate environment. Vectors are preferably capable of autonomous replication. Typically, an expression vector comprises a transcription promoter, a gene or its coding region, and a transcription terminator. Gene expression is usually placed under the control of a promoter, and a gene is said to be "operably linked to" the promoter.

As used herein, the term "operably linked" is used to describe the connection between regulatory elements and a gene or its coding region. Typically, gene expression is placed under the control of one or more regulatory elements, for example, without limitation, constitutive or inducible promoters, tissue-specific regulatory elements, and enhancers. A gene or coding region is said to be "operably linked to" or "operatively linked to" or "operably associated with" the regulatory elements, meaning that the gene or coding region is controlled or influenced by the regulatory element. For instance, a promoter is operably linked to a coding sequence ifthe promoter effects transcription or expression of the coding sequence.

The term "construct, " as used herein, refers to a recombinant nucleic acid that has been generated for the purpose of the expression of a specific nucleotide sequence (s) , or that is to be used in the construction of other recombinant nucleotide sequences.

As used herein, the terms "nucleic acid" and "polynucleotide" are interchangeable and refer to any nucleic acid, whether composed of phosphodiester linkages or modified linkages such as phosphotriester, phosphoramidate, siloxane, carbonate, carboxymethylester, acetamidate, carbamate, thioether, bridged phosphoramidate, bridged methylene phosphonate, bridged phosphoramidate, bridged phosphoramidate, bridged methylene phosphonate, phosphorothioate, methylphosphonate, phosphorodithioate, bridged phosphorothioate or sultone linkages, and combinations of such linkages. The terms "nucleic acid" and "polynucleotide" also specifically include nucleic acids comprising or composed of bases other than the five biologically occurring bases (adenine, guanine, thymine, cytosine and uracil) .

The terms "regulatory element" and "expression control element" are used interchangeably and refer to nucleic acid molecules that can influence the expression of an operably linked coding sequence in a particular host organism. These terms are used broadly to cover all elements that promote or regulate transcription, including promoters, core elements required for basic interaction of RNA polymerase and transcription factors, upstream elements, enhancers, and response elements (see, e.g., Lewin, "Genes V" (Oxford University Press, Oxford) pages 847-873) . Exemplary regulatory elements in prokaryotes include promoters, operator sequences and ribosome binding sites. Regulatory elements that are used in eukaryotic cells can include, without limitation, transcriptional and translational control sequences, such as promoters, enhancers, splicing signals, polyadenylation signals, terminators, protein degradation signals, internal ribosome-entry element (IRES) , 2A sequences, and the like, that provide for and/or regulate expression of a coding sequence and/or production of an encoded polypeptide in a host cell.

As used herein, 2A sequences or elements refer to small peptides introduced as a linker between two proteins, allowing autonomous intraribosomal self-processing of polyproteins (See e.g., de Felipe. Genetic Vaccines and Ther. 2: 13 (2004) ; deFelipe et al. Traffic 5: 616-626 (2004) ) . These short peptides allow co-expression of multiple proteins from a single vector. Many 2A elements are known in the art. Examples of 2A sequences that can be used in the methods and system disclosed herein, without limitation, include 2A sequences from the foot-and-mouth disease virus (F2A) , equine rhinitis A virus (E2A) , Thosea asigna virus (T2A) , and porcine teschovirus-1 (P2A) as described in U.S. Patent Publication No. 20070116690.

As used herein, the term "promoter" is a nucleotide sequence that permits binding of a RNA polymerase and directs the transcription of a gene. Typically, a promoter is located in the 5' non-coding region of a gene, proximal to the transcriptional start site of the gene. Sequence elements within promoters that function in the initiation of transcription are often characterized by consensus nucleotide sequences. Examples of promoters include, but are not limited to, promoters from bacteria, yeast, plants, viruses, and mammals (including humans) . A promoter can be inducible, repressible, and/or constitutive. Inducible promoters initiate increased levels of transcription from DNA under their control in response to some change in culture conditions, such as a change in temperature.

As used herein, the term "enhancer" refers to a type of regulatory element that can increase the efficiency of transcription, regardless of the distance or orientation of the enhancer relative to the start site of transcription.

As used herein, the term "antibody" is used in the broadest sense and specifically covers human, non-human (e.g., murine) and humanized monoclonal antibodies (including full-length monoclonal antibodies) , polyclonal antibodies, multi-specific antibodies (e.g., bispecific antibodies) , and antibody fragments so long as they exhibit the desired biological activity. Various antibodies can be expressed using the system and method disclosed herein. "Antibodies" and "immunoglobulins" are usually heterotetrameric glycoproteins, composed of two identical light (L) chains and two identical heavy (H) chains. Each light chain is linked to a heavy chain by a disulfide bond. The number of disulfide linkages varies among the heavy chains of different immunoglobulin isotypes. Each heavy chain comprises a variable domain (VH) followed by a number of constant domains. Each light chain comprises a variable domain (VL) at one end and a constant domain at its other end. The constant domain of the light chain is aligned with the first constant domain of the heavy chain, and the light-chain variable domain is aligned with the variable domain of the heavy chain. While antibodies exhibit binding specificity to a specific antigen, immunoglobulins include both antibodies and other antibody-like molecules with the antigen specificity. Polypeptides of the latter kind are, for example, produced at low levels by the lymph system and at increased levels by myelomas.

As used herein, the term "variant" refers to a polynucleotide (or polypeptide) having a sequence substantially similar to a reference polynucleotide (or polypeptide) . In the case of a polynucleotide, a variant can have deletions, substitutions, additions of one or more nucleotides at the 5' end, 3' end, and/or one or more internal sites in comparison to the reference polynucleotide. Similarities and/or differences in sequences between a variant and the reference polynucleotide can be detected using conventional techniques known in the art, for example polymerase chain reaction (PCR) and hybridization techniques. Variant polynucleotides also include synthetically derived polynucleotides, such as those generated, for example, by using site-directed mutagenesis. Generally, a variant of a polynucleotide, including, but not limited to, a DNA, can have at least about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%or more sequence identity to the reference polynucleotide as determined by sequence alignment programs known by skilled artisans. In the case of a polypeptide, a variant can have deletions, substitutions, additions of one or more amino acids in comparison to the reference polypeptide. Similarities and/or differences in sequences between a variant and the reference polypeptide can be detected using conventional techniques known in the art, for example Western blot. Generally, a variant of a polypeptide, can have at least about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%or more sequence identity to the reference polypeptide as determined by sequence alignment programs known by skilled artisans.

As used herein, the term "transfection" refers to the introduction of a nucleic acid into a host cell, such as by contacting the cell with a recombinant AAV virus as described below.

As used herein, the term "transgene" refers to any nucleotide or DNA sequence that is integrated into one or more chromosomes of a target cell by human intervention. In some embodiment, the transgene comprises a polynucleotide that encodes an antibody or a variant thereof. The protein-encoding polynucleotide is generally operatively linked to other sequences that are useful for obtaining the desired expression of the gene of interest, such as transcriptional regulatory sequences. In some embodiments, the transgene can additionally comprise a nucleic acid or other molecule (s) that is used to mark the chromosome where it has integrated.

As used herein, "treatment" refers to a clinical intervention made in response to a disease, disorder or physiological condition manifested by a patient or to which a patient may be susceptible. The aim of treatment includes, but is not limited to, the alleviation or prevention of symptoms, slowing or stopping the progression or worsening of a disease, disorder, or condition and/or the remission of the disease, disorder or condition. "Treatments" refer to one or both of therapeutic treatment and prophylactic or preventative measures. Subjects in need of treatment include those already affected by a disease or disorder or undesired physiological condition as well as those in which the disease or disorder or undesired physiological condition is to be prevented.

As used herein, the term "effective amount" refers to an amount sufficient to effect beneficial or desirable biological and/or clinical results.

As used herein, a "subject" refers to an animal that is the object of treatment, observation or experiment. "Animal" includes cold-and warm-blooded vertebrates and invertebrates such as fish, shellfish, reptiles, and in particular, mammals. "Mammal, " as used herein, refers to an individual belonging to the class Mammalia and includes, but not limited to, humans, domestic and farm animals, zoo animals, sports and pet animals. Non-limiting examples of mammals include mice; rats; rabbits; guinea pigs; dogs; cats; sheep; goats; cows; horses; primates, such as monkeys, chimpanzees and apes, and, in particular, humans. In some embodiments, the mammal is a human. However, in some embodiments, the mammal is not a human.

Adeno-Associated Virus (AAV) Vector

Adeno-associated virus (AAV) is a replication-deficient parvovirus, the single-stranded DNA genome of which is about 4.7 kb in length including 145 nucleotide inverted terminal repeat (ITRs) . The ITRs play a role in integration of the AAV DNA into the host cell genome. When AAV infects a host cell, the viral genome integrates into the host's chromosome resulting in latent infection of the cell. In a natural system, a helper virus (for example, adenovirus or herpesvirus) provides genes that allow for production of AAV virus in the infected cell. In the case of adenovirus, genes E1A, E1B, E2A, E4 and VA provide helper functions. Upon infection with a helper virus, the AAV provirus is rescued and amplified, and both AAV and adenovirus are produced. In the instances of recombinant AAV vectors having no Rep and/or Cap genes, the AAV can be non-integrating.

AAV vectors that comprise coding regions of one or more antibodies or variants thereof, for example proteins that are more than 500 amino acids in length, are provided. The AAV vector can include a 5' inverted terminal repeat (ITR) of AAV, a 3' AAV ITR, a promoter, and a restriction site downstream of the promoter to allow insertion of a polynucleotide encoding one or more antibodies or variants thereof, wherein the promoter and the restriction site are located downstream of the 5' AAV ITR and upstream of the 3' AAV ITR. In some embodiments, the recombinant AAV vector includes a post-transcriptional regulatory element downstream of the restriction site and upstream of the 3' AAV ITR. In some embodiments, the AAV vectors disclosed herein can be used as AAV transfer vectors carrying a transgene encoding an antibody or variant thereof for producing recombinant AAV viruses that can express the antibody or variant thereof in a host cell.

Generation of the viral vector can be accomplished using any suitable genetic engineering techniques well known in the art, including, without limitation, the standard techniques of restriction endonuclease digestion, ligation, transformation, plasmid purification, and DNA sequencing, for example as described in Sambrook et al. (Molecular Cloning: A Laboratory Manual. Cold Spring Harbor Laboratory Press, N.Y. (1989) ) .

The viral vector can incorporate sequences from the genome of any known organism. The sequences can be incorporated in their native form or can be modified in any way to obtain a desired activity. For example, the sequences can comprise insertions, deletions or substitutions.

Promoters

Various promoters can be operably linked with a nucleic acid comprising the coding region of the antibody or variant thereof in the viral vector disclosed herein. In some embodiments, the promoter can drive the expression of the antibody or variant thereof in a cell infected with a virus derived from the viral vector, such as a target cell. The promoter can be naturally-occurring or non-naturally occurring.

Examples of promoters, include, but are not limited to, viral promoters, plant promoters and mammalian promoters. Examples of viral promoters include, but not limited to, cytomegalovirus (CMV) immediate early promoter, CAG promoter (which is a combination of the CMV early enhancer element and chicken beta-actin promoter, described in Alexopoulou et al. BMC Cell Biology 9: 2, (2008) ) , simian virus 40 (SV40) promoter (the 35S RNA and 19S RNA promoters of cauliflower mosaic virus (CaMV) described in Brisson et al., Nature 1984, 310: 511-514) , the coat protein promoter to tobacco mosaic virus (TMV) , and any variants thereof. Examples of plant promoters include, but are not limited to, heat shock promoters, such as soybean hsp17.5-E or hsp17.3-B described in Gurley et al., Mol. Cell. Biol. 1986, 6: 559-565, and any variants thereof. Examples of mammalian promoters include, but are not limited to, human elongation factor 1. alpha. -subunit (EF1-1. alpha. ) promoter, human ubiquitin C (UCB) promoter, murine phosphoglycerate kinase-1 (PGK) promoter, and any variants thereof.

In some embodiments, the promoter is a synthetic promoter comprising at least a portion of the CAG promoter. The portion of the CAG promoter can comprise a nucleic acid sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 3.

In some embodiments, the promoter comprises a CMV enhancer. In some embodiments, the promoter comprises a UBC enhancer. In some embodiments, the promoter comprises at least a portion of the CMV enhancer. For example, the CMV enhancer can comprise a nucleic acid sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 2. In some embodiments the promoter comprises at least a portion of the UCB enhancer. The UCB enhancer can comprise a nucleic acid sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 4.

In some embodiments, the promoter is a synthetic CASI promoter having a nucleotide sequence of SEQ ID NO: 1. The synthetic CASI promoter contains a portion of the CMV enhancer, a portion of the chicken beta-actin promoter, and a portion of the UBC enhancer. In some embodiments, the promoter can include a nucleic acid sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 1. In some embodiments, the promoter comprises a nucleic acid sequence that is at least about 90%identical to SEQ ID NO: 1. In some embodiments, the promoter comprises a nucleic acid sequence that is at least about 95%identical to SEQ ID NO: 1. In some embodiments, the promoter comprises a nucleic acid sequence of SEQ ID NO: 1.

In some embodiments, the vector can include one or more introns to facilitate processing of the RNA transcript in mammalian host cells. A non-limiting example of such an intron is the rabbit beta-globin intron. In some embodiments, the intron is a synthetic intron. For example, the synthetic intron can include a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 8. The location of the intron in the vector can vary. In some embodiments, the intron is located between the promoter and the restriction site. In some embodiments, the intron is located within the promoter. In some embodiments, the intron includes a UCB enhancer. The UCB enhancer can comprise a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 4.

In some embodiments, the promoter is operably linked with a polynucleotide encoding one or more antibodies or variants thereof. In some embodiments, the promoter is operably linked with a polynucleotide encoding the heavy chain and/or the light chain of an antibody of interest (such as the heavy and light variable region of the antibody) . In some embodiments, the promoter is operably linked with a polynucleotide encoding the heavy chain and the light chain of an antibody of interest to allow multicistronic expression of the heavy and light chain genes. In some embodiments, a 2A sequence or IRES element is located between the coding region of the heavy chain variable region and the coding region of the light chain variable region in the vector to facilitate equivalent expression of each subunit. Alternatively, polynucleotides encoding the heavy and light chains can be introduced separately into the target cell, each in an appropriate viral vector.

The size of the promoter can vary. Because of the limited packaging capacity of AAV, it is preferred to use a promoter that is small in size, but at the same time allows high level production of the protein (s) of interest in host cells. For example, in some embodiments the promoter is at most about 1.5 kb, at most about 1.4 kb, at most about 1.35 kb, at most about 1.3 kb, at most about 1.25 kb, at most about 1.2 kb, at most about 1.15 kb, at most about 1.1 kb, at most about 1.05 kb, at most about 1 kb, at most about 800 base pairs, at most about 600 base pairs, at most about 400 base pairs, at most about 200 base pairs, or at most about 100 base pairs.

The nucleotide sequence of the promoter can also be modified for improving expression efficiency. For example, the promoter can include one or more splice donors, one or more splice acceptors, and/or combination thereof. In some embodiments, the promoter includes a splice donor and a splice acceptor. In some embodiments, the promoter includes one or more splice donors, and no splice acceptor. In some embodiments, the promoter includes no splice donor, and one or more splice acceptors. For example, in some embodiments the splice donor can comprise a nucleic acid sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 5. In some embodiments the splice acceptor can comprise a nucleic acid sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 6.

Regulatory Elements

Various post-transcriptional regulatory elements can be used in the viral vectors, for example to increase expression level of the antibody or variant thereof in a host cell. In some embodiments, the post-transcriptional regulatory element can be a viral post-transcriptional regulatory element. Non-limiting examples of viral post-transcriptional regulatory element include woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) , hepatitis B virus post-transcriptional regulatory element (HBVPRE) , RNA transport element (RTE) , and any variants thereof. The WPRE can comprise a nucleic acid sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 7. The RTE can be a rev response element (RRE) , for example, a lentiviral RRE. A non-limiting example is bovine immunodeficiency virus rev response element (RRE) . In some embodiments, the RTE is a constitutive transport element (CTE) . Examples of CTE include, but are not limited to, Mason-Pfizer Monkey Virus CTE and Avian Leukemia Virus CTE.

The viral vector described herein can include a prokaryotic replicon, that is, aDNA sequence having the ability to direct autonomous replication and maintenance of the recombinant DNA molecule extra-chromosomally in a prokaryotic host cell, such as a bacterial host cell, transformed therewith. Such replicons are well known in the art. In addition, vectors that include a prokaryotic replicon may also include a gene whose expression confers a detectable marker such as a drug resistance. Typical bacterial drug resistance genes are those that confer resistance to ampicillin or tetracycline.

In some embodiments, the AAV vector can include a gene for a selectable marker that is effective in an eukaryotic cell, such as a drug resistance selection marker. This selectable marker gene can encode a factor necessary for the survival or growth of transformed host cells grown in a selective culture medium. Host cells not transformed with the vector containing the selection gene will not survive in the culture medium. Typical selection genes encode proteins that confer resistance to antibiotics or other toxins, e.g., ampicillin, neomycin, methotrexate, kanamycin, gentamycin, Zeocin, or tetracycline, complement auxotrophic deficiencies, or supply critical nutrients withheld from the media.

The viral vectors disclosed herein can include various regulatory elements, such as a transcription initiation region and/or a transcriptional termination region. Examples of the transcription termination region include, but are not limited to, polyadenylation signal sequences. Examples of the polyadenylation signal sequences include, but are not limited to, Bovine growth hormone (BGH) poly (A) , SV40 late poly (A) , rabbit beta-globin (RBG) poly (A) , thymidine kinase (TK) poly (A) sequences, and any variants thereof. In some embodiments, the transcriptional termination region is located downstream of the post-transcriptional regulatory element. In some embodiments, the transcriptional termination region is a polyadenylation signal sequence. In some embodiments, the transcriptional termination region is SV40 late poly (A) sequence.

In some embodiments, the viral vectors can include additional sequences that make the vectors suitable for replication and integration in eukaryotes. In other embodiments, the viral vectors disclosed herein can include a shuttle element that makes the vectors suitable for replication and integration in both prokaryotes and eukaryotes. In some embodiments, the viral vectors can include additional transcription and translation initiation sequences, such as promoters and enhancers; and additional transcription and translation terminators, such as polyadenylation signals.

In some embodiment, the viral vectors can include a regulatory sequence that allows, for example, the translation of multiple proteins from a single mRNA. Non-limiting examples of such regulatory sequences include internal ribosome entry site (IRES) and 2A self-processing sequence. In some embodiments, the 2A sequence is a 2A peptide site from foot-and-mouth disease virus (F2A sequence) . In some embodiments, the F2A sequence has a standard furin cleavage site. For example, the F2A sequence having a standard furin cleavage site can include a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 9. In some embodiments, the F2A sequence has a modified furin cleavage site. For example, the F2A sequence having a modified furin cleavage site can include a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 10.

The viral vectors can also, in some embodiments, have one or more restriction site (s) located near the promoter sequence to provide for the insertion of nucleic acid sequences encoding one or more antibodies or variants thereof and other protein (s) .

Antibody or Variant thereof

As used herein, an "antibody or variant thereof" can be any protein, including naturally-occurring and non-naturally occurring proteins. In some embodiments, a polynucleotide encoding one or more antibodies or variants thereof can be inserted into the viral vectors disclosed herein, wherein the polynucleotide is operably linked with the promoter. In some instances, the promoter can drive the expression of the protein (s) of interest in a host cell (e.g., a human muscle cell) .

Examples of the antibody or variant thereof include, but are not limited to, luciferases; fluorescent proteins (e.g., GFP) ; growth hormones (GHs) and variants thereof; insulin-like growth factors (IGFs) and variants thereof; granulocyte colony-stimulating factors (G-CSFs) and variants thereof; erythropoietin (EPO) and variants thereof; insulin, such as proinsulin, preproinsulin, insulin, insulin analogs, and the like; antibodies and variants thereof, such as hybrid antibodies, chimeric antibodies, humanized antibodies, monoclonal antibodies; antigen binding fragments of an antibody (Fab fragments) , single-chain variable fragments of an antibody (scFV fragments) ; dystrophin and variants thereof; clotting factors and variants thereof; cystic fibrosis transmembrane conductance regulator (CFTR) and variants thereof; and interferons and variants thereof.

In some embodiments, the antibody or variant thereof is a therapeutic protein or variant thereof. Non-limiting examples of therapeutic proteins include blood factors, such as beta-globin, hemoglobin, tissue plasminogen activator, and coagulation factors; colony stimulating factors (CSF) ; interleukins, such as IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, etc.; growth factors, such as keratinocyte growth factor (KGF) , stem cell factor (SCF) , fibroblast growth factor (FGF, such as basic FGF and acidic FGF) , hepatocyte growth factor (HGF) , insulin-like growth factors (IGFs) , bone morphogenetic protein (BMP) , epidermal growth factor (EGF) , growth differentiation factor-9 (GDF-9) , hepatoma derived growth factor (HDGF) , myostatin (GDF-8) , nerve growth factor (NGF) , neurotrophins, platelet-derived growth factor (PDGF) , thrombopoietin (TPO) , transforming growth factor alpha (TGF-alpha) , transforming growth factor beta (TGF-beta) , and the like; soluble receptors, such as soluble TNF-alpha receptors, soluble VEGF receptors, soluble interleukin receptors (e.g., soluble IL-1 receptors and soluble type II IL-1 receptors) , soluble gamma/delta T cell receptors, ligand-binding fragments of a soluble receptor, and the like; enzymes, such as alpha-glucosidase, imiglucarase, beta-glucocerebrosidase, and alglucerase; enzyme activators, such as tissue plasminogen activator; chemokines, such as IP-10, monokine induced by interferon-gamma (Mig) , Gro alpha/IL-8, RANTES, MIP-1 alpha, MIP-1 beta, MCP-1, PF-4, and the like; angiogenic agents, such as vascular endothelial growth factors (VEGFs, e.g., VEGF121, VEGF165, VEGF-C, VEGF-2) , transforming growth factor-beta, basic fibroblast growth factor, glioma-derived growth factor, angiogenin, angiogenin-2; and the like; anti-angiogenic agents, such as a soluble VEGF receptor; protein vaccine; neuroactive peptides, such as nerve growth factor (NGF) , bradykinin, cholecystokinin, gastin, secretin, oxytocin, gonadotropin-releasing hormone, beta-endorphin, enkephalin, substance P, somatostatin, prolactin, galanin, growth hormone-releasing hormone, bombesin, dynorphin, warfarin, neurotensin, motilin, thyrotropin, neuropeptide Y, luteinizing hormone, calcitonin, insulin, glucagons, vasopressin, angiotensin II, thyrotropin-releasing hormone, vasoactive intestinal peptide, a sleep peptide, and the like; thrombolytic agents; atrial natriuretic peptide; relaxin; glial fibrillary acidic protein; follicle stimulating hormone (FSH) ; human alpha-1 antitrypsin; leukemia inhibitory factor (LIF) ; transforming growth factors (TGFs) ; tissue factors, luteinizing hormone; macrophage activating factors; tumor necrosis factor (TNF) ; neutrophil chemotactic factor (NCF) ; nerve growth factor; tissue inhibitors of metalloproteinases; vasoactive intestinal peptide; angiogenin; angiotropin; fibrin; hirudin; IL-1 receptor antagonists; and the like. Some other non-limiting examples of antibody or variant thereof include ciliary neurotrophic factor (CNTF) ; brain-derived neurotrophic factor (BDNF) ; neurotrophins 3 and 4/5 (NT-3 and 4/5) ; glial cell derived neurotrophic factor (GDNF) ; aromatic amino acid decarboxylase (AADC) ; hemophilia related clotting proteins, such as Factor VIII, Factor IX, Factor X; dystrophin or nini-dystrophin; lysosomal acid lipase; phenylalanine hydroxylase (PAH) ; glycogen storage disease-related enzymes, such as glucose-6-phosphatase, acid maltase, glycogen debranching enzyme, muscle glycogen phosphorylase, liver glycogen phosphorylase, muscle phosphofructokinase, phosphorylase kinase (e.g., PHKA2) , glucose transporter (e.g., GLUT2) , aldolase A, beta-enolase, and glycogen synthase; lysosomal enzymes (e.g., beta-N-acetylhexosaminidase A) ; and any variants thereof.

In some embodiments, the antibody or variant thereof is an active fragment of a protein, such as any of the aforementioned proteins. In some embodiments, the antibody or variant thereof is a fusion protein comprising some or all of two or more proteins. In some embodiments a fusion protein can comprise all or a portion of any of the aforementioned proteins.

In some embodiments, the viral vector comprises a polynucleotide comprising coding regions for two or more antibodies or variants thereof. The two or more antibodies or variants thereof can be the same or different from each other. In some embodiments, the two or more antibodies or variants thereof are related polypeptides, for example neutralizing antibodies for the same virus.

In some embodiments, the antibody or variant thereof is a multi-subunit protein. For examples, the antibody or variant thereof can comprise two or more subunits, or two or more independent polypeptide chains. In some embodiments, the antibody or variant thereof can be an antibody. Examples of antibodies include, but are not limited to, antibodies of various isotypes (for example, IgG1, IgG2, IgG3, IgG4, IgA, IgD, IgE, and IgM) ; monoclonal antibodies produced by any means known to those skilled in the art, including an antigen-binding fragment of a monoclonal antibody; humanized antibodies; chimeric antibodies; single-chain antibodies; antibody fragments such as Fv, F (ab') 2, Fab', Fab, Facb, scFv and the like; provided that the antibody is capable of binding to an antigen. In some embodiments, the antibody is a full-length antibody. In some embodiments, the antibody or variant thereof is not an immune-adhesin.

In some embodiments, the antibody is a viral neutralizing antibody. For example, the antibody can be a neutralizing antibody against SARS-CoV-2. In some embodiments, the antibody is a neutralizing anti-SARS-CoV-2 antibody. In some embodiments, a neutralizing anti-SARS-CoV-2 antibody may be, for example, ahuman monoclonal neutralizing antibody that neutralizes SARS-CoV-2.

As described herein, the nucleotide sequence encoding the antibody or variant thereof can be modified to improve expression efficiency of the protein. The methods that can be used to improve the transcription and/or translation of a gene herein are not particularly limited. For example, the nucleotide sequence can be modified to better reflect host codon usage to increase gene expression (e.g., protein production) in the host (e.g., a mammal) . As another non-limiting example for the modification, one or more of the splice donors and/or splice acceptors in the nucleotide sequence of the antibody or variant thereof is modified to reduce the potential for extraneous splicing.

The antibody or variant thereof can be of various lengths. For example, the antibody or variant thereof can be at least about 200 amino acids, at least about 250 amino acids, at least about 300 amino acids, at least about 350 amino acids, at least about 400 amino acids, at least about 450 amino acids, at least about 500 amino acids, at least about 550 amino acids, at least about 600 amino acids, at least about 650 amino acids, at least about 700 amino acids, at least about 750 amino acids, at least about 800 amino acids, or longer in length. In some embodiments, the antibody or variant thereof is at least about 480 amino acids in length. In some embodiments, the antibody or variant thereof is at least about 500 amino acids in length. In some embodiments, the antibody or variant thereof is about 750 amino acids in length.

When it is desired to include coding regions for two or more antibodies or variants thereof, two or more individual polypeptide chains, or two or more subunits of an antibody or variant thereof in one viral vector, each additional coding region beyond the first is preferably linked to an element that facilitates co-expression of the proteins in host cells, such as an internal ribosomal entry sequence (IRES) element (U.S. Pat. No. 4,937,190) , or a 2A element. For example, IRES or 2A elements are preferably used when a single vector comprises sequences encoding each subunit of a multi-subunit protein. In the case of that the antibody or variant thereof is immunoglobulin with a desired specificity, for example, the first coding region (encoding either the heavy or light chain of immunoglobulin) is located downstream from the promoter. The second coding region (encoding the remaining chain of immunoglobulin) can be located downstream from the first coding region, and an IRES or 2A element can be disposed between the two coding regions, preferably immediately preceding the second coding region. The incorporation of an IRES or 2A element between the sequences of a first and second gene (encoding the heavy and light chains, respectively) can allow both chains to be expressed from the same promoter at about the same level in the cell.

In some embodiments, the antibody or variant thereof comprises two or more subunits of, for example an immunoglobulin (Ig) . The viral vector can include a coding region for each of the subunits. For example, the viral vector can include both the coding region for the Ig heavy chain (or the variable region of the Ig heavy chain) and the coding region for the Ig light chain (or the variable region of the Ig light chain) . In some embodiments, the vectors include a first coding region for the heavy chain variable region of an antibody, and a second coding region for the light chain variable region of the antibody. The two coding regions can be separated, for example, by a 2A self-processing sequence to allow multi-cistronic transcription of the two coding regions.

The viral vector can include coding regions for two or more antibodies or variants thereof. For example, the viral vector can include the coding region for a first antibody or variant thereof and the coding region for a second antibody or variant thereof. The first antibody or variant thereof and the second antibody or variant thereof can be the same or different. In some embodiments, the viral vector can include the coding region (s) for a third or a fourth antibody or variant thereof. The third and the fourth antibody or variant thereof can be the same or different. The total length of the two or more antibodies or variants thereof encoded by one viral vector can vary. For example, the total length of the two or more proteins can be at least about 400 amino acids, at least about 450 amino acids, at least about 500 amino acids, at least about 550 amino acids, at least about 600 amino acids, at least about 650 amino acids, at least about 700 amino acids, at least about 750 amino acids, at least about 800 amino acids, or longer.

The Kozak consensus sequence, Kozak consensus or Kozak sequence, is known as a sequence which occurs on eukaryotic mRNA and has the consensus (gcc) gccRccAUGG, where R is a purine (adenine or guanine) three bases upstream of the start codon (AUG) , which is followed by another "G. " In some embodiments, the vector comprises a nucleotide sequence having at least about 70%, at least about 80%, at least about 90%sequence identity, or more to the Kozak consensus sequence. In some embodiments, the vector comprises a Kozak consensus sequence. In some embodiments, the vector includes a Kozak consensus sequence after the polynucleotide encoding one or more antibodies or variants thereof is inserted into the vector, e.g., at the restrict site downstream of the promoter. For example, the vector can include a nucleotide sequence of GCCGCCATG (SEQ ID NO: 32) , where the ATG is the start codon of the antibody or variant thereof. In some embodiments, the vector comprises a nucleotide sequence of GCGGCCGCCATG (SEQ ID NO: 33) , where the ATG is the start codon of the antibody or variant thereof.

The antibody or variant thereof can be isolated and purified, if desired, in accordance with conventional methods known to those skilled in the art. For example, a lysate can be prepared from the expression host cells and the lysate can be purified using HPLC, hydrophobic interaction chromatography (HIC) , anion exchange chromatography, cation exchange chromatography, size exclusion chromatography, ultrafiltration, gel electrophoresis, affinity chromatography, and/or other purification techniques.

Signal Peptide Sequence

Various signal peptide sequences can be used in the viral vector disclosed herein. The signal peptide sequence can be naturally-occurring or non-naturally occurring.

In some embodiments, a signal peptide can provide for secretion from a mammalian cell. Examples of signal peptides include, but are not limited to, the endogenous signal peptide for HGH and variants thereof; the endogenous signal peptide for interferons and variants thereof, including the signal peptide of type I, II and III interferons and variants thereof; and the endogenous signal peptides for known cytokines and variants thereof, such as the signal peptide of erythropoietin (EPO) , insulin, TGF-beta 1, TNF, IL1-alpha, and IL1-beta, and variants thereof. In some embodiments, the signal peptide is a modified HGH signal peptide. In some embodiments, the nucleotide sequence encoding the signal peptide comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 11. In some embodiments, the nucleotide sequence encoding the signal peptide comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 12.

In some embodiments, the signal polypeptide for a protein that is different from the antibody or variant thereof can be used. In some embodiments, the native signal polypeptide for the antibody or variant thereof is used. In some instances, anon-naturally occurring signal peptide can be used.

Typically, the nucleotide sequence of the signal peptide is located immediately upstream of the coding region of the antibody or variant thereof (e.g., fused at the 5' of the coding region of the antibody or variant thereof) in the vector. In the instances where the viral vector includes the coding regions of two or more antibodies or variants thereof, signal peptide sequence can be inserted immediately upstream of one or more of the coding regions. In some embodiments, each of the coding regions has a signal peptide sequence fused at the 5' end. The signal peptide sequence added to each of the coding region can be the same or different. For example, when the antibody or variant thereof has two subunits, the viral vector can include a coding region for one of the subunits and a coding region for the other subunit, and a signal peptide sequence can be inserted immediately upstream of either one of the coding regions, or both of the coding regions. As another non-limiting example, the viral vector can include a coding region for the heavy chain variable region of an immunoglobulin and a coding region for the light chain variable region of the immunoglobulin, and each of the coding regions is fused with a signal peptide sequence at the 5' end. In some embodiments, the two signal peptide sequences are the same. In some embodiments, the two signal peptide sequences are different.

In some embodiments, following protein expression and/or secretion, the signal peptides can be cleaved from the precursor proteins resulting in mature proteins.

AAV Vectors of the Disclosure

In some embodiments, the region in the viral vector starting from the 5' AAV ITR and ending at the 3' AAV ITR can be delivered to a host cell and integrate into the host cell genome. The length of this region can vary. For example, the length of this region can be at least about 2 kb, at least about 2.25 kb, at least about 2.5 kb, at least about 2.75 kb, at least about 3 kb, at least about 3.25 kb, at least about 3.5 kb, at least about 3.75 kb, at least about 4 kb, at least about 4.25 kb, or at least about 4.5 kb. In some embodiments, this region is at least about 2.5 kb. In some embodiments, this region is about 4.5 kb. In some embodiments, the viral vector is not a self-complementary AAV (scAAV) vector.

As disclosed above, the viral vectors can include various elements, for example, but not limited to, a promoter, a transgene encoding the antibody or variant thereof, a signal peptide sequence, a post-transcriptional regulatory element, a transcriptional terminal element, and a regulatory sequence allowing translation of multiple proteins from a single mRNA. A skilled artisan will appreciate that a viral vector can include one of these elements, or any combinations of two or more of these elements.

As described above, the nucleotide sequence of each of the above-listed elements can be modified to increase the expression efficiency of the antibody or variant thereof in a host cell. In some embodiments wherein more than one transgenes are present in the viral vector, a sequence that can facilitate the co-expression of the transgenes can be used. Non-limiting examples of such sequence include IRES, 2A sequence, and variants thereof.

Sequences of non-limiting examples of the AAV vectors are provided in SEQ ID NOs: 13-30. For example, the nucleotide sequence for an AAV vector including the CMV promoter, coding sequences for anti-SARS-CoV-2 antibody and SV40 late poly (A) sequence is set forth in SEQ ID NO: 13.

In some embodiments, the AAV vector comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to any one of SEQ ID NOs: 13-30. In some embodiments, the AAV vector comprises a nucleotide sequence having at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or more, sequence identity to SEQ ID NO: 31.

In some embodiments, the viral vector includes the CMV promoter and SV40 late poly (A) sequence. In some embodiments, the AAV vector includes the CASI synthetic promoter, WPRE and SV40 late poly (A) sequence. In some embodiments, the AAV vector includes the CASI synthetic promoter, WPRE and rabbit beta-globin (RBG) poly (A) sequence. In some embodiments, the AAV vector includes the CASI synthetic promoter, WPRE and bovine growth hormone (BGH) poly (A) sequence. In some embodiments, the viral vector includes the CAG promoter and SV40 late poly (A) sequence. In some embodiments, the viral vector includes the CAG promoter, WPRE and SV40 late poly (A) sequence.

Method for Producing Recombinant AAVs

The present application provides methods and materials for producing recombinant AAVs that can express one or more antibodies or variants thereof in a host cell. As described herein, the methods and materials disclosed herein allow for high production of the antibodies or variants thereof, for example, an antibody, such as a full-length antibody.

In some embodiments, methods for producing a recombinant AAV include providing a packaging cell line with a viral construct comprising a 5' inverted terminal repeat (ITR) of AAV and a 3' AAV ITR, such as described herein, helper functions for generating a productive AAV infection, and AAV cap genes; and recovering a recombinant AAV from the supernatant of the packaging cell line. Various types of cells can be used as the packaging cell line. For example, packaging cell lines that can be used include, but are not limited to, HEK 293 cells, HeLa cells, and Vero cells, for example as disclosed in US Patent Publication No. 20110201088.

In some embodiments, the supernatant of the packaging cell line is treated by PEG precipitation for concentrating the virus. In some embodiments, the precipitation occurs at no more than about 4℃ (for example about 3℃, about 2℃, about 1℃, or about 1℃) for at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 6 hours, at least about 9 hours, at least about 12 hours, or at least about 24 hours. In some embodiments, the recombinant AAV is isolated from the PEG-precipitated supernatant by low-speed centrifugation followed by CsCl gradient. The low-speed centrifugation can be at about 4000 rpm, about 4500 rpm, about 5000 rpm, or about 6000 rpm for about 20 minutes, about 30 minutes, about 40 minutes, about 50 minutes or about 60 minutes. In some embodiments, the recombinant AAV is isolated from the PEG-precipitated supernatant by centrifugation at about 5000 rpm for about 30 minutes followed by CsCl gradient.

In some embodiments, the viral construct further comprises a promoter and a restriction site downstream of the promoter to allow insertion of a polynucleotide encoding one or more antibodies or variants thereof, wherein the promoter and the restriction site are located downstream of the 5' AAV ITR and upstream of the 3' AAV ITR. In some embodiments, the viral construct further comprises a post-transcriptional regulatory element downstream of the restriction site and upstream of the 3' AAV ITR. In some embodiments, the viral construct further comprises a polynucleotide inserted at the restriction site and operably linked with the promoter, where the polynucleotide comprises the coding region of an antibody or variant thereof. As a skilled artisan will appreciate, any one of the AAV vectors disclosed in the present application can be used in the method as the viral construct to produce the recombinant AAV.

In some embodiments, the helper functions are provided by one or more helper plasmids or helper viruses comprising adenoviral helper genes. Non-limiting examples of the adenoviral helper genes include E1A, E1B, E2A, E4 and VA, which can provide helper functions to AAV packaging.

In some embodiments, the AAV cap genes are present in a plasmid. The plasmid can further comprise an AAV rep gene. It is contemplated by the present application that the cap genes and/or rep gene from any AAV serotype (including, but not limited to, AAV1, AAV2, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, and any variants thereof) can be used herein to produce the recombinant AAV disclosed herein to express one or more antibodies or variants thereof, or fusion proteins or variants thereof. In some embodiments, the AAV cap genes encode a capsid from serotype 1, serotype 2, serotype 4, serotype 5, serotype 6, serotype 7, serotype 8, serotype 9, or a variant thereof,

In some embodiments, the packaging cell line can be transfected with the helper plasmid or helper virus, the viral construct and the plasmid encoding the AAV cap genes; and the recombinant AAV virus can be collected at various time points after co-transfection. For example, the recombinant AAV virus can be collected at about 12 hours, about 24 hours, about 36 hours, about 48 hours, about 72 hours, about 96 hours, about 120 hours, or a time between any of these two time points after the co-transfection.

Helper viruses of AAV are known in the art and include, for example, viruses from the family Adenoviridae and the family Herpesviridae. Examples of helper viruses of AAV include, but are not limited to, SAdV-13 helper virus and SAdV-13-like helper virus described in US Publication No. 20110201088, helper vectors pHELP (Applied Viromics) . A skilled artisan will appreciate that any helper virus or helper plasmid of AAV that can provide adequate helper function to AAV can be used herein.

The recombinant AAV viruses disclosed herein can also be produced using any convention methods known in the art suitable for producing infectious recombinant AAV. In some instances, a recombinant AAV can be produced by using a cell line that stably expresses some of the necessary components for AAV particle production. For example, a plasmid (or multiple plasmids) comprising AAV rep and cap genes, and a selectable marker, such as a neomycin resistance gene, can be integrated into the genome of a cell (the packaging cells) . The packaging cell line can then be co-infected with a helper virus (e.g., adenovirus providing the helper functions) and the viral vector comprising the 5' and 3' AAV ITR and the nucleotide sequence encoding the protein (s) of interest. The advantages of this method are that the cells are selectable and are suitable for large-scale production of the recombinant AAV. As another non-limiting example, adenovirus or baculovirus rather than plasmids can be used to introduce rep and cap genes into packaging cells. As yet another non-limiting example, both the viral vector containing the 5' and 3' AAV ITRs and the rep-cap genes can be stably integrated into the DNA of producer cells, and the helper functions can be provided by a wild-type adenovirus to produce the recombinant AAV.

In some embodiments, the recombinant AAV is not a self-complementary AAV(scAAV) .

As will be appreciated with a skilled artisan, any conventional methods suitable for purifying AAV can be used in the embodiments described herein to purify the recombinant AAV. For example, the recombinant AAV can be isolated and purified from packaging cells and/or the supernatant of the packaging cells. In some embodiments, the AAV can be purified by separation method using a CsCl gradient. Also, US Patent Publication No. 20020136710 describes another non-limiting example of method for purifying AAV, in which AAV was isolated and purified from a sample using a solid support that includes a matrix to which an artificial receptor or receptor-like molecule that mediates AAV attachment is immobilized.

Applications of the Viral Vectors and Recombinant AAV

The viral vectors disclosed herein can be used to generate recombinant AAV expressing the protein (s) of interest. The proteins produced by the recombinant AAV generated by the methods and systems described herein have a wide variety of utilities, for example, they can be useful in applications such as diagnostics, therapeutics, research, compound screening and drug discovery.

Production of Proteins In Vitro

As a non-limiting example, the recombinant AAV disclosed herein can be used to produce an antibody or variant thereof in vitro, for example, in a cell culture. As one non-limiting example, in some embodiments, a method for producing an antibody or variant thereof in vitro, includes providing a recombinant AAV comprising a nucleotide sequence encoding the antibody or variant thereof; and contacting the recombinant AAV with a cell in a cell culture, whereby the recombinant AAV expresses the antibody or variant thereof in the cell. The size of the nucleotide sequence encoding the antibody or variant thereof can vary. For example, the nucleotide sequence can be at least about 1.4 kb, at least about 1.5 kb, at least about 1.6 kb, at least about 1.7 kb, at least about 1.8 kb, at least about 2.0 kb, at least about 2.2 kb, at least about 2.4 kb, at least about 2.6 kb, at least about 2.8 kb, at least about 3.0 kb, at least about 3.2 kb, at least about 3.4 kb, or at least about 3.5 kb in length. In some embodiments, the nucleotide is at least about 1.4 kb in length.

As disclosed above, the antibody or variant thereof is not in any way limited. For example, the antibody or variant thereof can be an antibody, for example a viral neutralizing antibody. The recombinant AAV disclosed here can produce high levels of the antibodies or variants thereof in vitro.

In some embodiments, the antibody or variant thereof is luciferase or a fluorescent protein (e.g., GFP) . The recombinant AAV expressing the fluorescent protein can be used for labeling cells with fluorescent allowing visualization of the infected cells, for example muscle cells.

Production of Proteins In Vivo

As a non-limiting example, the recombinant AAV disclosed herein can be used to produce an antibody or variant thereof in vivo, for example in an animal such as a mammal. Some embodiments provide a method for producing an antibody or variant thereof in vivo, where the method includes providing a recombinant AAV comprising a nucleotide sequence encoding the antibody or variant thereof; and administering the recombinant AAV to the subject, whereby the recombinant AAV expresses the antibody or variant thereof in the subject. The subject can be, in some embodiments, a non-human mammal, for example, a monkey, a dog, a cat, a mouse, or a cow. The size of the nucleotide sequence encoding the antibody or variant thereof can vary. For example, the nucleotide sequence can be at least about 1.4 kb, at least about 1.5 kb, at least about 1.6 kb, at least about 1.7 kb, at least about 1.8 kb, at least about 2.0 kb, at least about 2.2 kb, at least about 2.4 kb, at least about 2.6 kb, at least about 2.8 kb, at least about 3.0 kb, at least about 3.2 kb, at least about 3.4 kb, or at least about 3.5 kb in length. In some embodiments, the nucleotide is at least about 1.4 kb in length.

As disclosed above, the antibody or variant thereof is not in any way limited. For example, the antibody or variant thereof can be an antibody, for example a viral neutralizing antibody. The recombinant AAV disclosed herein can produce high levels of the antibodies or variants thereof in vivo. For example, the antibody or variant thereof can be expressed in the serum of the subject in the amount of at least about 9 μg/ml, at least about 10 μg/ml, at least about 50 μg/ml, at least about 100 μg/ml, at least about 200 μg/ml, at least about 300 μg/ml, at least about 400 μg/ml, at least about 500 μg/ml, at least about 600 μg/ml, at least about 700 μg/ml, at least about 800 μg/ml, at least about 900 μg/ml, or at least about 1000 μg/ml. In some embodiments, the antibody or variant thereof is expressed in the serum of the subject in the amount of about 9 μg/ml, about 10 μg/ml, about 50 μg/ml, about 100 μg/ml, about 200 μg/ml, about 300 μg/ml, about 400 μg/ml, about 500 μg/ml, about 600 μg/ml, about 700 μg/ml, about 800 μg/ml, about 900 μg/ml, about 1000 μg/ml, about 1500 μg/ml, about 2000 μg/ml, about 2500 μg/ml, or a range between any two of these values. In some embodiments, the antibody or variant thereof is expressed in the serum of the subject in the amount of at least about 9 μg/ml. In some embodiments, the antibody or variant thereof is expressed in the serum of the subject in the amount of at least about 100 μg/ml. In some embodiments, the antibody or variant thereof is expressed in the serum of the subject in the amount of at least about 500 μg/ml.

Therapeutic Applications

The recombinant AAV and methods described herein can be used to express one or more antibodies or variant thereof to prevent or treat viral infection, especially coronavirus infection in a subject.

The recombinant AAV and methods described herein can be used to inhibit or reduce the risk of various viral infections. Some embodiments disclose a method for reducing or inhibiting the infection risk of a virus in a subject, where the method include providing a recombinant AAV comprising a nucleotide sequence encoding a neutralizing antibody for the virus; and administering the recombinant AAV to the subject, whereby the recombinant AAV expresses the antibody in the subject. The recombinant AAV can produce high level of viral neutralizing antibody. For example, in some embodiments, the recombinant AAV can express in the serum of the subject in the amount of at least about 9 μg/ml, at least about 10 μg/ml, at least about 50 μg/ml, at least about 100 μg/ml, at least about 200 μg/ml, at least about 300 μg/ml, at least about 400 μg/ml, at least about 500 μg/ml, at least about 600 μg/ml, at least about 700 μg/ml, at least about 800 μg/ml, at least about 900 μg/ml, or at least about 1000 μg/ml of the viral neutralizing antibody. In some embodiments, the viral neutralizing antibody is expressed in the serum of the subject in the amount of about 9 μg/ml, about 10 μg/ml, about 50 μg/ml, about 100 μg/ml, about 200 μg/ml, about 300 μg/ml, about 400 μg/ml, about 500 μg/ml, about 600 μg/ml, about 700 μg/ml, about 800 μg/ml, about 900 μg/ml, about 1000 μg/ml, about 1500 μg/ml, about 2000 μg/ml, about 2500 μg/ml, or a range between any two of these values.

The method disclosed herein can, for example, reduce the infection risk in the subject by at least about 2 fold, at least about 3 fold, at least about 4 fold, at least about 5 fold, at least about 8 fold, at least about 10 fold, at least about 15 fold, at least about 20 fold, at least about 25 fold, or at least about 30 fold as compared to the subjects without the viral treatment. In some embodiments, the method can reduce the infection risk in the subject by about 2 fold, about 3 fold, about 4 fold, about 5 fold, about 8 fold, about 10 fold, about 15 fold, about 20 fold, about 25 fold, about 30 fold, or a range between any two of these values as compared to the subjects without the viral treatment. In some embodiments, the method reduces the infection risk in the subject with the viral treatment by at least about 5 fold as compared to the subjects without the viral treatment. In some embodiments, the method reduces the infection risk in the subject with the viral treatment by at least about 20 fold as compared to the subjects without the viral treatment. In some embodiments, the method prevents the viral infection from occurring in the subject. In some embodiments, the method inhibits the viral infection in the subject.

Some embodiments provide a method of reducing the risk of viral infection for a subject who has been exposed to a virus (for example, a subject who has come into contact with another subject infected with a virus) . Some embodiments provide a method of reducing the risk of viral infection for a subject who will be exposed to a virus (for example, a subject who will come into contact with another subject infected with a virus) . In some embodiments, a method of preventing the viral infection is provided.

The amount of the antibody or variant thereof expressed in the subject (e.g., the serum of the subject) can vary. For example, in some embodiments the protein or antibody can be expressed in the serum of the subject in the amount of at least about 9 μg/ml, at least about 10 μg/ml, at least about 50 μg/ml, at least about 100 μg/ml, at least about 200 μg/ml, at least about 300 μg/ml, at least about 400 μg/ml, at least about 500 μg/ml, at least about 600 μg/ml, at least about 700 μg/ml, at least about 800 μg/ml, at least about 900 μg/ml, or at least about 1000 μg/ml. In some embodiments, the antibody or variant thereof is expressed in the serum of the subject in the amount of about 9 μg/ml, about 10 μg/ml, about 50 μg/ml, about 100 μg/ml, about 200 μg/ml, about 300 μg/ml, about 400 μg/ml, about 500 μg/ml, about 600 μg/ml, about 700 μg/ml, about 800 μg/ml, about 900 μg/ml, about 1000 μg/ml, about 1500 μg/ml, about 2000 μg/ml, about 2500 μg/ml, or a range between any two of these values. A skilled artisan will understand that the expression level in which an antibody or variant thereof is needed for the method to be effective can vary depending on non-limiting factors such as the particular antibody or variant thereof and the subject receiving the treatment, and an effective amount of the protein can be readily determined by a skilled artisan using conventional methods known in the art without undue experimentation.

A skilled artisan will appreciate the one or more of the viral vectors and recombinant AAV can be used together in the applications described herein. For example, recombinant AAV viruses expressing different antibodies or variants thereof or different subunits of an antibody or variant thereof can be administered to the same subject for diagnostic and/or therapeutic purposes. In some embodiments, the recombinant viruses are co-administered to the subject. In some embodiments, the recombinant viruses are administered to the subject separately. In some embodiments, the first antibody or variant thereof is an anti-SARS-CoV-2 neutralizing antibody and the second antibody or variant thereof is a different anti-SARS-CoV-2 neutralizing antibody. In some embodiments, a first recombinant AAV expressing a first subunit of the antibody or variant thereof and a second recombinant AAV expressing a second subunit of the antibody or variant thereof can be administered to the subject together or separately.

Pharmaceutical Composition and Method of Administration

Also disclosed herein are pharmaceutical compositions comprising the recombinant AAV viruses disclosed herein and a pharmaceutically acceptable carrier. The compositions can also comprise additional ingredients such as diluents, stabilizers, excipients, and adjuvants. As used herein, "pharmaceutically acceptable" carriers, excipients, diluents, adjuvants, or stabilizers are the ones nontoxic to the cell or subject being exposed thereto (preferably inert) at the dosages and concentrations employed or that have an acceptable level of toxicity as determined by the skilled practitioner.

The carriers, diluents and adjuvants can include buffers such as phosphate, citrate, or other organic acids; antioxidants such as ascorbic acid; low molecular weight polypeptides (e.g., less than about 10 residues) ; proteins such as serum albumin, gelatin or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as Tween ^TM, Pluronics ^TM, or polyethylene glycol (PEG) . In some embodiments, the physiologically acceptable carrier is an aqueous pH buffered solution.

Titers of the recombinant AAV virus to be administered will vary depending, for example, on the particular recombinant AAV virus, the mode of administration, the treatment goal, the individual, and the cell type (s) being targeted, and can be determined by methods standard in the art.

As will be readily apparent to one skilled in the art, the useful in vivo dosage of the recombinant virus to be administered and the particular mode of administration will vary depending upon the age, weight, the severity of the affliction, and animal species treated, the particular recombinant virus expressing the antibody or variant thereof that is used, and the specific use for which the recombinant virus is employed. The determination of effective dosage levels, that is the dosage levels necessary to achieve the desired result, can be accomplished by one skilled in the art using routine pharmacological methods. Typically, human clinical applications of products are commenced at lower dosage levels, with dosage level being increased until the desired effect is achieved. Alternatively, acceptable in vitro studies can be used to establish useful doses and routes of administration of the compositions identified by the present methods using established pharmacological methods.

Although the exact dosage will be determined on a drug-by-drug basis, in most cases, some generalizations regarding the dosage can be made. In some embodiments, the recombinant AAV expressing an antibody or variant thereof can be administered via injection to a subject at a dose of between 1×10 ¹¹ genome copies (GC) of the recombinant virus per kg of the subject and 1×10 ¹³ GC per kg, for example between 1×10 ¹¹ GC/kg and 5×10 ¹² GC/kg.

The recombinant viruses disclosed herein can be administered to a subject (e.g., a human) in need thereof. The route of the administration is not particularly limited. For example, a therapeutically effective amount of the recombinant viruses can be administered to the subject via routes standard in the art. Non-limiting examples of the route include intramuscular, intravaginal, intravenous, intraperitoneal, subcutaneous, epicutaneous, intradermal, rectal, intraocular, pulmonary, intracranial, intraosseous, oral, buccal, or nasal. In some embodiments, the recombinant virus is administered to the subject by intramuscular injection. In some embodiments, the recombinant virus is administered to the subject by intravaginal injection. In some embodiments, the recombinant AAV is administered to the subject by the parenteral route (e.g., by intravenous, intramuscular or subcutaneous injection) , by surface scarification or by inoculation into a body cavity of the subject. Route (s) of administration and serotype (s) of AAV components of the recombinant AAV virus can be readily determined by one skilled in the art taking into account the infection and/or disease state being treated and the target cells/tissue (s) that are to express the antibody or variant thereof. In some embodiments, the recombinant virus is administered to muscle cells.

Actual administration of the recombinant AAV virus can be accomplished by using any physical method that will transport the recombinant AAV virus into the target tissue of the subject. For example, the recombinant AAV virus can be injected into muscle, the bloodstream, and/or directly into the liver. Capsid proteins of the recombinant AAV virus may be modified so that the recombinant AAV virus is targeted to a particular target tissue of interest such as muscle and vagina. Pharmaceutical compositions can be prepared as injectable formulations or as topical formulations to be delivered to the muscles by transdermal transport.

For intramuscular injection, solutions in an adjuvant such as sesame or peanut oil or in aqueous propylene glycol can be employed, as well as sterile aqueous solutions. Such aqueous solutions can be buffered, if desired, and the liquid diluent first rendered isotonic with saline or glucose. Solutions of the recombinant AAV virus as a free acid (DNA contains acidic phosphate groups) or a pharmacologically acceptable salt can be prepared in water suitably mixed with a surfactant such as hydroxpropylcellulose. A dispersion of the recombinant AAV virus can also be prepared in glycerol, liquid polyethylene glycols and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.

The recombinant virus to be used can be utilized in liquid or freeze-dried form (in combination with one or more suitable preservatives and/or protective agents to protect the virus during the freeze-drying process) . For gene therapy (e.g., of neurological disorders which may be ameliorated by a specific gene product) a therapeutically effective dose of the recombinant virus expressing the therapeutic protein is administered to a host in need of such treatment. The use of the recombinant virus disclosed herein in the manufacture of a medicament for inducing immunity in, or providing gene therapy to, a host is within the scope of the present application.

In instances where human dosages for the recombinant AAV viruses have been established for at least some condition, those same dosages, or dosages that are between about 0.1%and 500%, more preferably between about 25%and 250%of the established human dosage can be used. Where no human dosage is established, as will be the case for newly-discovered pharmaceutical compositions, a suitable human dosage can be inferred from ED ₅₀ or ID ₅₀ values, or other appropriate values derived from in vitro or in vivo studies, as qualified by toxicity studies and efficacy studies in animals.

A therapeutically effective amount of the recombinant AAV can be administered to a subject at various points of time. For example, the recombinant AAV can be administered to the subject prior to, during, or after the infection by a virus. The recombinant AAV can also be administered to the subject prior to, during, or after the occurrence of a disease (e.g., COVID-19) . In some embodiments, the recombinant AAV is administered to the subject during COVID-19 remission. In some embodiments, the recombinant AAV is administered prior to infection by the virus for immunoprophylaxis.

The dosing frequency of the recombinant AAV virus can vary. For example, the recombinant AAV virus can be administered to the subject about once every week, about once every two weeks, about once every month, about one every six months, about once every year, about once every two years, about once every three years, about once every four years, about once every five years, about once every six years, about once every seven years, about once every eight years, about once every nine years, about once every ten years, or about once every fifteen years. In some embodiments, the recombinant AAV virus is administered to the subject at most about once every week, at most about once every two weeks, at most about once every month, at most about one every six months, at most about once every year, at most about once every two years, at most about once every three years, at most about once every four years, at most about once every five years, at most about once every six years, at most about once every seven years, at most about once every eight years, at most about once every nine years, at most about once every ten years, or at most about once every fifteen years.

EXAMPLES

Additional embodiments are disclosed in further detail in the following examples, which are not in any way intended to limit the scope of the claims.

Example 1. Production of ACE2-Fc Fusion Protein for Treating SARS-CoV-2

ACE2-Fc fusion proteins and their use for treating SARS-CoV-2 are described in China patent application No. CN202010132178.7, filed on Feb. 29, 2020, the priority of which is claimed herein, and whose entire content is incorporated herein by reference.

Example 2. Production of Rabbit Anti-SARS-CoV-2 Spike Protein Antibodies for Treating SARS-CoV-2

Rabbit anti-SARS-CoV-2 spike protein antibodies and their use for treating SARS-CoV-2 are described in China patent application No. CN202010442784.9, filed on May 22, 2020, the priority of which is claimed herein, and whose entire content is incorporated herein by reference.

Example 3. Production of Mouse Anti-SARS-CoV-2 Spike Protein Monoclonal Antibodies for Treating SARS-CoV-2

Mouse anti-SARS-CoV-2 spike protein monoclonal antibodies and their use for treating SARS-CoV-2 are described in China patent application No. CN202010451374.0, filed on May 25, 2020, the priority of which is claimed herein, and whose entire content is incorporated herein by reference.

Example 4. Production of Human Anti-SARS-CoV-2 Spike Protein Monoclonal Antibodies for Treating SARS-CoV-2

Mouse anti-SARS-CoV-2 spike protein monoclonal antibodies and their use for treating SARS-CoV-2 are described in International patent application No. PCT/CN2020/092748, filed on May 28, 2020, the priority of which is claimed herein, and whose entire content is incorporated herein by reference.

Example 5. Production of Camelid Anti-SARS-CoV-2 Spike Protein Antibodies for Treating SARS-CoV-2

Camelid anti-SARS-CoV-2 spike protein monoclonal antibodies and their use for treating SARS-CoV-2 are described in China patent application No. PCT/CN2020/092934, filed on May 28, 2020, the priority of which is claimed herein, and whose entire content is incorporated herein by reference.

Example 6. Production of Anti-SARS-CoV-2 N Protein Antibodies for Treating SARS-CoV-2

Mouse anti-SARS-CoV-2 N protein monoclonal antibodies and their use for treating SARS-CoV-2 are described in China patent application No. 202010566590. X, filed on June 19, 2020, the priority of which is claimed herein, and whose entire content is incorporated herein by reference.

Example 7. AAV vector construction and production

7.1 AAV packaging vectors

Recombinant AAV vectors were produced from mammalian cells transfected with three plasmids components.

The first plasmid contained the rep and cap genes of AAV genome, where the expression can be driven by AAV native promoters, p5, p19 and p40 in either intact form or truncated form.

The second plasmid containing the nucleic sequence, encoding an ACE2-Fc fusion protein or a variant thereof of Example 1 or an antibody or a variant thereof of Examples 2 to 6, inserted between the 5’ -and 3’ -AAV inverted terminal repeats (ITR) , was packaged into AAV capsids and transferred to the targeted cells. The nucleic sequence encoding an antibody or a variant thereof encoded either the light chain or heavy chain alone, or light and heavy chains connected by a self-cleaving peptide sequence, of one of the antibodies disclosed herein. Regulatory sequences (e.g. promoters, enhancers, introns, polyadenylation signals) were inserted between 5’ -and 3’-ITRs, downstream and/or upstream of the fusion protein/antibody coding sequence.

The third plasmid contained adenovirus genes that are essential for AAV genome replication and packaging.

7.2 Production of AAV

For production of AAV vectors in adherent HEK293T cells, low passage number (P6-9) cells were sub-cultured at a density of 7.0 x 10 ⁴ cells/cm ² in DMEM with 5%FBS 1 day before transfection. The three plasmids were co-transfected at a 1: 1: 1 molar ratio with PEI at a mass ratio of DNA: PEI=1: 2. Culture medium was replaced by fresh one 6 hrs after the transfection. The cells were maintained for another 2 days before harvest and further purification.

Cells were detached with 0.05%Trypsin-EDTA, pelleted by centrifugation at 800 x g for 4 min at 4℃ and lysed with 100μL of 0.01 M PBS plus 1.0 mM MgCl ₂, 2.5 mM KCl and 0.1% (v/v) Triton-X 100 per 5.0 x10 ⁶ cells at 37℃ for 30 min. Cell debris were removed by centrifugation at 14,000 x g at 4℃ for 15 min. The AAV vectors in the supernatant were precipitated with PEG8000 and NaCl at a concentration of 8% (w/v) and 1.0 M, respectively, at 4℃ overnight and then centrifuged at 2,000 x g at 4℃ for 30 min. The precipitate was re-suspended with PBS-MK 1/2 of the lysis volume and incubated with 50 U/mL benzonase at 37℃ for 30 min. Two volumes of chloroform was added and vortexed vigorously for 2 min to extract proteins. After centrifugation at<1,000 x g for 5 min, the aqueous phase was subjected to chloroform extraction for one more time. The aqueous phase from the 2nd chloroform extraction was weighed and subjected to phase separation with PEG and (NH ₄) ₂SO ₄ at a final concentration of 10% (w/v) and 13.3% (w/w) , respectively, at pH 8.0. The mixture was vigorously vortexed and kept still for 30 min at room temperature. After centrifugation at 2,500 x g for 15 min at RT, the clear bottom phase was collected and subjected to ultracentrifugation.

Four concentrations of iodixanol solutions were placed in the ultracentrifugal tube from bottom to top in the following order, 5 mL 60%, 5 mL 40%, 6 mL 25%and 9 mL 15%. The AAV-containing solution from the previous step was overlaid on the top of the iodixanol solution. After ultracentrifugation at 350,000 x g for 2 hrs at 18℃, the solution in the 40%layer was collected and subjected to ultrafiltration with 100 kDa filter to remove iodixanol and sterilization. The concentrated vectors were stored in 0.01M PBS with 0.01%Pluronic F68.

Example 8. AAV Quantification and Functional Validation in Vitro

8.1 DDPCR to quantify AAV

Frozen aliquots of AAV were thawed and diluted tenfold in digestion buffer containing 10 U/mL of Benzonase (Merck) and incubated at 37℃ for 30 minutes to digest cell-free DNA fragments. AAV-containing samples were further diluted so that a 20-μL reaction system contained 2E+04～1E+05 copies of complete genomic DNAs. Dilution factor needed to be pre-determined. The reaction system also contained 18μM of forward (WPRE-F: 5′-ATGAGGAGTTGTGGCCCGTT-3′ (SEQ ID NO: 34) ) and reverse primers (5′-CTCCTTTCCGGGACTTTCGC-3′ (SEQ ID NO: 35) ) respectively and 5 μM of Taqman probe (5′-6FAM-CACCACGCCACGTTGCCTGA-BHQ1-3′ (SEQ ID NO: 36) ) . Host cell genomic DNA without AAV genomic DNA was used for negative control and packaging plasmid with GOI for AAV packaging as positive control. Droplets were generated with droplet generator and transferred to a 96-well PCR plate and heat-sealed. The following cycling conditions were used: one cycle of 95℃ for 10 minutes, 40 cycles of 94℃ for 30 seconds and 60℃ for 60 seconds, one cycle of 98℃ for 10 minutes, and hold at 4℃. The plate was then loaded on QX200 Droplet Reader to measure fluorescent signal of droplet stream in each well. Mass concentration and copy numbers can be interconverted by the following equation:

Copies/μL= (6.02×10 ²³) × (ng/μL×10 ^-9) / (DNA length×660)

8.2 Purification of Antibodies or fusion proteins from AAV-Transduced Cells

To validate the functional activity of each lot of the titrated virus, in vitro infection assays were performed using 293F cells and the concentration of the antibodies/fusion proteins in the cell supernatant was measured. Antibodies/fusion proteins in the culture supernatant were loaded on protein A affinity chromatography column and washed with 0.02 M sodium phosphate, pH 7.0. The column was washed with 0.02 M sodium phosphate, pH 7.0 and bounded antibodies/fusion proteins were eluted with 0.1 M sodium citrate, pH 3.0.

8.3 Pseudotype virus neutralizing activity

Purified antibodies/fusion proteins from AAV transduced cells were diluted with OptiMEM to 25μl and mixed with 25μl pseudo SARS-CoV-2 viruses. The antibodies/fusion proteins and viruses were incubated at room temperature for 1 hour and mixed with 100μl HEK293FT-ACE cell suspension and added into one well of a 96-well plate. The infected HEK293FT-ACE cells were lysated at 48 hour after infection with 50 cell lysis buffer. After a freeze-and-thaw, 30μl cell lysis was transferred to a luciferase detection plate and mixed with 30μl Luciferase substrate. The luminescence was measured by plate reader and recorded.

8.4 Live virus neutralizing activity

Vero-E6 cells were seeded in 24 wells plate at 160,000 cells/well in 24 wells in 1 ml complete DMEM medium. After 24 hours, purified antibodies/fusion proteins from AAV transduced cells were diluted with PBS to 50μl and mixed with 150 FFU SARS-CoV-2 viruses. The antibodies/fusion proteins and viruses were incubated at room temperature for 1 hour and added into Vero-E6 cells. The uninfected virions were washed out 1 hour later and methyl cellulose was added onto infected Vero-E6 cells. After 24 hours, methyl cellulose was peeled off and cells were stained with 0.1%crystal violet. The colored cell plaques were counted to calculate infection inhibition rate.

Infection inhibition rate = 1 – (Average plaques number in wells without antibody/fusion protein treatment –Average plaque number in wells with antibody/fusion protein treatment) /Average plaques number in wells without antibody/fusion protein treatment x 100%.

Example 9. Antibody/Fusion protein pharmacokinetics in AAV transduced mice

Balb/c mice at 4 weeks of age were anaesthetized with a mixture of 70 mg/kg of body weight ketamine and 7 mg/kg of body weight xylazine by intraperitoneal (IP) injection for all intramuscular (IM) injections. Vectors were diluted in phosphate buffered saline (PBS) with P-F68, and IM injections were performed using a Hamilton syringe. Sera were collected weekly from mice administered with vectors expressing secreted antibodies/fusion proteins by retro-orbital bleeds into serum collection tubes. Collected sera were diluted in PBS and incubated with anti-idiotype antibody A coated 96-well plate and washed with PBS for three times. PBS with HRP labeled anti-idiotype antibody B was added to detect bound anti-SARS-CoV-2 antibodies/fusion proteins. Unbound anti-idiotype antibody was washed out with PBS, and HRP activity was measured by OD450 after adding HRP substrate. Anti-SARS2-antibody/fusion protein concentration was calculated by fitting the OD450 value to protein standard curve.

Example 10. Live virus challenge in AAV transduced mice

Balb/c mice at 4 weeks of age were anaesthetized with a mixture of 70 mg/kg of body weight ketamine and 7 mg/kg of body weight xylazine by intraperitoneal (IP) injection for all intramuscular (IM) injections. AVVs were diluted in phosphate buffered saline (PBS) with P-F68 and IM injections were performed using a Hamilton syringe. Four weeks after AAV injection, Balb/c mice were lightly anesthetized with isoflurane and transduced intranasally with 2.5×10 ⁸ FFU of Ad5-ACE2 in 75μl DMEM. Five days post transduction, mice were infected intranasally with SARS-CoV-2 (1×10 ⁵ PFU) in a total volume of 50μl DMEM. Mice were monitored and weighted daily. On day 1 and day 3 post infection, lungs of 3 infected mice were collected and the SARS-CoV-2 infectious titer in the lung were measured. On day 4 post infection, the lung of 1 infected mouse was collected for H&E staining.

Example 11. Prevention of SARS-CoV-2 Virus Infection

This example illustrates immunoprophylaxis of a patient at risk of having SARS-CoV-2 virus infection.

A recombinant AAV was produced using an AAV transfer vector comprising a polynucleotide encoding an anti-SARS-CoV-2 neutralizing antibody disclosed above. Any known anti-SARS-CoV-2 neutralizing antibody can be used, and an ACE-Fc fusion protein may also be used.

A subject was identified as being at risk of developing SARS-CoV-2 infection and administered an effective amount of the recombinant AAVs. The recombinant AAV was administered to the subject by intramuscular injection. The recombinant AAV expressed anti-SARS-CoV-2 antibody in the subject, thereby reducing the risk for the subject to develop SARS-CoV-2 virus injection. The appropriate dosage (i.e., the expression level of the anti-SARS-CoV-2 neutralizing antibody) and treatment regimen can be readily determined by skilled artisans based on a number of factors including, but not limited to, the route of administration and the extent of SARS-CoV-2 virus exposure for the subject. The SARS-CoV-2 viral load in the subject can be determined at various time points after the patient being administered with the recombinant AAV. The immunoprophylaxis efficacy is evaluated by observing reduced risk of SARS-CoV-2 infection as compared to the subject receiving no AAV administration.

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In at least some of the previously described embodiments, one or more elements used in an embodiment can interchangeably be used in another embodiment unless such a replacement is not technically feasible. It will be appreciated by those skilled in the art that various other omissions, additions and modifications may be made to the methods and structures described above without departing from the scope of the claimed subject matter. All such modifications and changes are intended to fall within the scope of the subject matter, as defined by the appended claims.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to, " the term "having" should be interpreted as "having at least, " the term "includes" should be interpreted as "includes but is not limited to, " etc. ) . It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more" ) ; the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations, " without other modifiers, means at least two recitations, or two or more recitations) . Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc. " is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. ) . In those instances where a convention analogous to "at least one of A, B, or C, etc. " is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc. ) . It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or" A and B. "

In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to, " "at least, " "greater than, " "less than, " and the like include the number recited and refer to ranges which can be subsequently broken down into sub-ranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 articles refers to groups having 1, 2, or 3 articles. Similarly, a group having 1-5 articles refers to groups having 1, 2, 3, 4, or 5 articles, and so forth.

While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims

A viral vector, where the viral vector comprises: a 5' inverted terminal repeat (ITR) of adeno-associated virus (AAV) and a 3' AAV ITR, a promoter, a restriction site downstream of the promoter to allow insertion of a polynucleotide encoding a SARS-CoV-2-neutralizing antibody or a variant thereof, or an ACE2-Fc fusion protein or a variant thereof, and a post-transcriptional regulatory element downstream of the restriction site, where the promoter, the restriction site and the post-transcription regulatory element are located downstream of the 5' AAV ITR and upstream of the 3' AAV ITR.
The vector of claim 1, wherein the viral vector further comprises a polynucleotide inserted at the restriction site and operably linked with the promoter, where the polynucleotide comprises a coding region of an SARS-CoV-2 neutralizing antibody or a variant thereof, or a coding region of anACE2-Fc fusion protein or a variant thereof.
The vector of claim 2, wherein the viral vector further comprises a signal peptide sequence immediately upstream of the coding region of the antibody or variant thereof, or the coding region of the ACE2-Fc fusion protein or variant thereof.
The vector of claim 3, wherein the signal peptide is selected from the group consisting of a signal peptide of interferon, a signal peptide of human growth hormone, a signal peptide of erythropoietin (EPO) , a signal peptide of granulocyte colony-stimulating factor (G-CSF) , a signal peptide of insulin, and any combination thereof.
The vector of claim 1, which further comprises a nucleotide sequence having at least about 90%sequence identity to the Kozak consensus sequence.
The vector of claim 1, wherein the antibody or variant thereof is selected from the group consisting of a full-length antibody, an antibody Fab fragment, an antibody scFv fragment, a single chain antibody (sdAb) , a bispecific single-domain antibody fused to a monoclonal antibody (SMAB) , and any variant thereof.
The vector of claim 1, wherein promoter comprises a splice donor, a splice acceptor, or any variant thereof.
The vector of claim 7, wherein the splice donor comprises a nucleotide sequence having at least 90%sequence identity to SEQ ID NO: 5.
The vector of claim 7, wherein the splice acceptor comprises a nucleotide sequence having at least 90%sequence identity to SEQ ID NO: 6.
The vector of claim 1, wherein the promoter comprises a nucleotide sequence having at least 90%sequence identity to SEQ ID NO: 1.
The vector of claim 1, wherein the promoter comprises a nucleotide sequence having at least 90%sequence identity to any one of SEQ ID NOs: 2-4.
The vector of claim 1, wherein the post-transcriptional regulatory element is a viral post-transcriptional regulatory element.
The vector of claim 12, wherein the viral post-transcriptional regulatory element is woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) , hepatitis B virus post-transcriptional regulatory element (HBVPRE) , RNA transport element (RTE) , or any variant thereof.
The vector of claim 1, wherein the viral vector further comprises a transcription termination region downstream of the post-transcriptional regulatory element.
The vector of claim 14, wherein the transcription termination region comprises an SV40 late poly (A) sequence, a rabbit beta-globin poly (A) sequence, a bovine growth hormone poly (A) sequence, or any variant thereof.
The vector of claim 1, wherein the promoter comprises an intron, wherein the intron is a synthetic intron comprising a nucleotide sequence having at least 90%sequence identity to SEQ ID NO: 8.
The vector of claim 2, wherein the polynucleotide comprises a first coding region for the heavy chain variable region of an immunoglobulin and a second coding region for the light chain variable region of the immunoglobulin, wherein the first coding region and the second coding region are separatedby a 2A sequence.
The vector of claim 17, wherein the 2A sequence is an F2A sequence.
The vector of claim 17, wherein 5' of the first coding region is fused with a first signal peptide sequence and 5' of the second coding region is fused with a second signal peptide sequence.
The vector of claim 19, wherein the first signal peptide sequence and the second signal peptide sequence are different.
The vector of claim 1, wherein the antibody is selected from the group consisting of an antibody of Examples 2-6, or any variant thereof.
A method for reducing or inhibiting the infection risk of a virus in a subject, where the method comprises: providing a recombinant adeno-associated virus (AAV) comprising a nucleotide sequence encoding a neutralizing antibody or a variant thereof for the virus, or an ACE2-Fc fusion protein; and administering the recombinant AAV to the subject, whereby the recombinant AAV expresses the antibody, or variant thereofor the ACE2-Fc fusion protein in the subject.
The method of claim 22, wherein the method further comprises providing a second recombinant AAV comprising a nucleotide sequence encoding a second neutralizing antibody or a variant thereof for the virus.
The method of claim 22, wherein the virus is SARS-CoV-2.