CN117466994A

CN117466994A - Monkey pox virus monoclonal neutralizing antibody and application thereof

Info

Publication number: CN117466994A
Application number: CN202310889094.1A
Authority: CN
Inventors: 王奇慧; 高福; 仵丽丽; 赵润初; 刘德志
Original assignee: Institute of Microbiology of CAS
Current assignee: Institute of Microbiology of CAS
Priority date: 2023-07-19
Filing date: 2023-07-19
Publication date: 2024-01-30

Abstract

The invention belongs to the field of biological medicine, and in particular relates to a monoclonal neutralizing antibody for monkey pox virus B6 and M1 antigens and application thereof. The invention provides two monoclonal neutralizing antibodies targeting the B6 antigen and two monoclonal neutralizing antibodies targeting the M1 antigen of the monkey pox virus, which can be widely combined with proteins homologous to B6 or M1 in the B6 or M1 antigen of the monkey pox virus, vaccinia virus, smallpox virus and vaccinia virus, can neutralize orthopoxvirus infection represented by the vaccinia virus, can be used for preventing and treating orthopoxvirus infection including but not limited to the monkey pox virus, the vaccinia virus, the smallpox virus, the vaccinia virus and the like, and has a great application prospect.

Description

Monkey pox virus monoclonal neutralizing antibody and application thereof

Technical Field

The invention belongs to the field of biological medicine, and in particular relates to a monoclonal neutralizing antibody for monkey pox virus B6 and M1 antigens and application thereof.

Background

Monkey Poxviruses (MPXV) belong to the genus orthopoxvirus, which also includes Variola virus (VARV), vaccinia virus (vaccina virus, VACV), and Vaccinia virus (cowpoxvirus, CPXV), and the like, and infections in humans can cause diseases of varying severity, jeopardizing human health.

Monkey pox (Mpox) belongs to zoonotic disease, and the first time a human infection case was found in 1970, and then spread locally in the middle and western regions of Africa for a long time, but since the diagnosis of monkey pox cases in the United kingdom in month 5 of 2022, the diagnosis of monkey pox cases was confirmed in multiple countries worldwide, indicating that the epidemic situation of monkey pox has assumed a global epidemic situation. Studies show that although smallpox vaccine has a certain immunity protection effect on smallpox, most of people (birth after 1980) lack resistance to orthopoxviruses such as smallpox virus and smallpox virus along with the elimination of smallpox and the stop of vaccination. Currently, although chemicals such as Tecovirimat, brincidofovir have been approved for the treatment of smallpox and vaccinia immunoglobulins (vaccinia immunoglobulin, VIG) have been approved for complications resulting from smallpox vaccination, and also for infection with orthopoxviruses such as monkey pox, their efficacy in other orthopoxviruses such as monkey pox has been limited. Currently, no effective drug against monkey poxvirus is used for the treatment of diseases.

Orthopoxviruses such as monkey pox virus belong to double stranded DNA viruses, have a genome size of about 200kb, encode up to 200 proteins, and have two different forms of infectious viral particles, intracellular mature particles (Intracellular mature virion, IMV) and extracellular capsular particles (Extracellular enveloped virion, EEV), respectively, with different capsular structures, modes of infection and surface antigens. M1, H3, A29, E8 on the surface of IMV and B6, A35 on the surface of EEV are shown to induce the generation of neutralizing antibodies, and thus become important targets for research of therapeutic antibodies, vaccines and the like.

The invention aims at screening monoclonal antibodies with neutralizing activity against the B6 antigen on the EEV surface and the M1 antigen on the IMV surface of the monkey pox virus.

Disclosure of Invention

The invention takes MPXV B6 expressed by mammalian cells as antigen, screens memory B cells which can specifically bind to the MPXV B6 antigen from PBMCs of smallpox vaccine vaccinated population by flow sorting, then carries out reverse transcription PCR and nested PCR on the sorted single B cells, amplifies the variable region sequence of the antibody by using specific primers, and is further connected with an antibody constant region into an expression vector. Through expressing and purifying the antibody by mammalian cells, a series of functional tests including binding capacity, neutralizing activity and the like are carried out, so that two human monoclonal antibodies D21 and D68 which have broad-spectrum binding MPXV, VACV, VARV, CPXV and can neutralize VACV infection are obtained. Meanwhile, the invention takes MPXV M1 expressed by mammalian cells as an antigen, screens B cells which can specifically bind to the MPXV M1 antigen from a surviving mouse lymph node inoculated with a monkey pox virus mRNA vaccine and protected by virus attack through flow separation, and then carries out 10 Xgenomic sequencing on the screened B cells to obtain an antibody variable region sequence, further synthesizes the variable region sequence and links the variable region sequence with an antibody constant region into an expression vector. Through expressing and purifying the antibody by mammal cells, a series of functional tests including binding capacity, neutralizing activity and the like are carried out, so that two strains of mouse monoclonal antibodies 39# and 40# which have broad-spectrum binding MPXV, VACV, VARV, CPXV and can neutralize VACV infection are obtained. Thus, the present invention has been completed.

The invention provides neutralizing antibodies and antigen binding fragments thereof against the B6 and M1 antigens of the monkey pox virus, in particular neutralizing antibodies D21, D68 or antigen binding fragments thereof against the B6 antigen of the monkey pox virus, or neutralizing antibodies 39#,40# or antigen binding fragments thereof against the M1 antigen of the monkey pox virus,

the three complementarity determining region CDRs of the D21 heavy chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 1,

CDR2 as shown in SEQ ID NO. 2, and

CDR3 as shown in SEQ ID NO. 3;

the three complementarity determining region CDRs of the D21 light chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 4,

CDR2 as shown in SEQ ID NO. 5, and

CDR3 as shown in SEQ ID NO. 6.

The three complementarity determining region CDRs of the D68 heavy chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 7,

CDR2 as shown in SEQ ID NO. 8, and

CDR3 as shown in SEQ ID NO 9;

the three complementarity determining region CDRs of the D68 light chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 10,

CDR2 as shown in SEQ ID NO. 11, and

CDR3 as shown in SEQ ID NO. 12.

The three complementarity determining region CDRs of the 39# heavy chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 13,

CDR2 as shown in SEQ ID NO. 14, and

CDR3 as shown in SEQ ID NO. 15;

the three complementarity determining region CDRs of the 39# light chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 16,

CDR2 as shown in SEQ ID NO 17, and

CDR3 as shown in SEQ ID NO. 18.

The three complementarity determining region CDRs of the 40# heavy chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 19,

CDR2 as shown in SEQ ID NO. 20, and

CDR3 as shown in SEQ ID NO. 21;

the three complementarity determining region CDRs of the 40# light chain variable region thereof have amino acid sequences selected from the group consisting of:

CDR1 as shown in SEQ ID NO. 22,

CDR2 as shown in SEQ ID NO. 23, and

CDR3 as shown in SEQ ID NO. 24.

Where "antigen binding fragment" refers to antigen binding fragments of antibodies and antibody analogs, it generally includes at least a portion of the antigen binding or variable regions of the parent antibody, e.g., one or more CDRs. Fragments of the antibodies retain at least some of the binding specificity of the parent antibody.

In one embodiment, the D21 antibody or antigen binding fragment thereof comprises:

a heavy chain variable region as shown in SEQ ID NO. 25, and

the light chain variable region as shown in SEQ ID NO. 26.

In one embodiment, the D68 antibody or antigen binding fragment thereof comprises:

a heavy chain variable region as shown in SEQ ID NO 27, and

the light chain variable region as shown in SEQ ID NO. 28.

In one embodiment, the 39# antibody or antigen binding fragment thereof comprises:

a heavy chain variable region as shown in SEQ ID NO. 29, and

the light chain variable region as shown in SEQ ID NO. 30.

In one embodiment, the 40# antibody or antigen binding fragment thereof comprises:

a heavy chain variable region as shown in SEQ ID NO. 31, and

the light chain variable region as shown in SEQ ID NO. 32.

In one embodiment, the antibody or antigen binding fragment thereof comprises:

a heavy chain constant region as shown in SEQ ID NO. 33, and

the light chain constant region as shown in SEQ ID NO. 34.

In one embodiment, wherein the antigen binding fragment is selected from the group consisting of Fab, fab '-SH, fv, scFv, F (ab') 2, diabodies, antibody compositions.

Wherein "Fab" consists of one light chain and one heavy chain variable region and CH 1.

"Fab' fragment" containsOne light chain and a portion of one heavy chain comprising a variable region and a region between CH1 or CH1 and CH2 domains, an interchain disulfide bond being formed between the two heavy chains of the two Fab 'fragments to form F (ab') ₂ A molecule.

“F(ab′) ₂ The fragment "comprises two light chains and two heavy chains comprising portions of the constant region between the CH1 and CH2 domains, thereby forming an interchain disulfide bond between the two heavy chains. Thus, F (ab') ₂ Fragments consist of two Fab' fragments held together by disulfide bonds between the two heavy chains.

The "Fv region" comprises variable regions from both the heavy and light chains, but lacks constant regions.

"Single chain Fv antibody (scFv antibody)" refers to an antigen-binding fragment comprising the variable regions of an antibody, which domains are contained in a single polypeptide chain. In general, scfvs comprise a polypeptide linker between the heavy and light chain variable regions that enables the scFv to form the desired structure for antigen binding.

A "diabody" is an antigen-binding fragment having two antigen-binding sites. The fragments comprise a VH (VH-VL or VL-VH) linked to a VL in the same polypeptide chain. By using a linker that is so short that it is not possible to pair between two domains of the same strand, the domains pair with complementary domains of the other strand and form two antigen binding sites.

An "antibody composition" comprises a mixture of antibodies.

The present invention provides a polynucleotide encoding a neutralizing antibody or antigen binding fragment or polypeptide thereof of any one of the preceding claims.

The present invention provides an expression vector comprising the polynucleotide described above.

The present invention provides a host cell comprising the above expression vector.

The invention provides the use of a neutralizing antibody or antigen binding fragment thereof of any of the above in the manufacture of a medicament for the treatment and prevention of orthopoxvirus infections including, but not limited to, monkey pox virus, vaccinia virus, smallpox virus, vaccinia virus, and the like.

The present invention provides a pharmaceutical composition comprising a neutralizing antibody or antigen binding fragment thereof of any one of the preceding claims and a pharmaceutically acceptable carrier.

The invention also provides pharmaceutical compositions comprising the monkey poxvirus neutralizing antibodies or antigen binding fragments thereof of the invention. For the preparation of pharmaceutical compositions, the antibodies or antigen-binding fragments thereof may be formulated into various desired dosage forms by mixing with pharmaceutically acceptable carriers or excipients. Examples of the type of the dosage form of the pharmaceutical composition of the present invention include tablets, powders, pills, powders, granules, fine granules, soft/hard capsules, film-coated agents, pellets, sublingual tablets, ointments and the like, which are oral preparations, and non-oral preparations include injections, suppositories, transdermal preparations, ointments, plasters, external solutions and the like, and those skilled in the art can select an appropriate dosage form depending on the route of administration, the administration subject and the like.

The amount of the active ingredient to be administered of the pharmaceutical composition of the present invention varies depending on the administration subject, the organ to be administered, the symptoms, the administration method, etc., and can be determined by considering the type of the dosage form, the administration method, the age and weight of the patient, the symptoms of the patient, etc., and the judgment of the doctor.

The invention has the beneficial effects that:

the screening of the invention obtains two target monkey pox virus B6 antigens and two target M1 antigen monoclonal neutralizing antibodies, which can be widely combined with the monkey pox virus B6 or M1 antigen and proteins homologous to B6 or M1 in vaccinia virus, smallpox virus and vaccinia virus, and can neutralize orthopoxvirus infection represented by vaccinia virus, and has the potential of treating and preventing orthopoxvirus infection including but not limited to monkey pox virus, vaccinia virus, smallpox virus, vaccinia virus and the like.

Drawings

Fig. 1: a kinetic profile of broad-spectrum binding of the D21 antibody to the B6-homologous antigen in MPXV B6 and VACV, VARV, CPXV;

fig. 2: kinetics curves for broad-spectrum binding of the D68 antibody to B6-homologous antigen in MPXV B6 and VACV, VARV, CPXV;

fig. 3: the # 39 antibody broad-spectrum binds to the kinetics profile of the M1-homologous antigen in MPXV M1 and VACV, VARV, CPXV;

fig. 4: a kinetic profile of broad-spectrum binding of antibody 40 to M1 homologous antigen in MPXV M1 and VACV, VARV, CPXV;

fig. 5: d21 and D68 neutralize the effect of orthopoxvirus infection typified by VACV.

Fig. 6: neutralization of the effects of the orthopoxvirus infection represented by VACV in # 39 and # 40.

The specific information of each sequence of the invention is as follows:

SEQ ID NO:1：GFSISTYP

SEQ ID NO:2：ISHDGRNK

SEQ ID NO:3：ARAYPYAFDVSEQ ID NO:4：QSVRND

SEQ ID NO:5：GAS

SEQ ID NO:6：QQYKDWPPWT

SEQ ID NO:7：GGTFSDYA

SEQ ID NO:8：ILPIVGVP

SEQ ID NO:9：ARRSGINGHGLDV

SEQ ID NO:10：QSLLNTNGYNY

SEQ ID NO:11：LGS

SEQ ID NO:12：MQTLQTQGYT

SEQ ID NO:13：GYTFTSYW

SEQ ID NO:14：INPSTGYT

SEQ ID NO:15：TRSDSTNYLFVY

SEQ ID NO:16：QSLLNSRTRKNH

SEQ ID NO:17：WAS

SEQ ID NO:18：KQSYNLMYT

SEQ ID NO:19：GYIFTRYW

SEQ ID NO:20：INPSTGYT

SEQ ID NO:21：ARSDYTNYVFEY

SEQ ID NO:22：QSLVHSNGNTY

SEQ ID NO:23：KVS

SEQ ID NO:24：SQSTHVPYT

SEQ ID NO:25：QVQLVQSGGGVVQPGRSLRLSCVASGFSISTYPLHWVRQAPGKGLE WVAVISHDGRNKYYADSVKGRFSISRDNSKNTVYLQMNSLRVEDTAVYYCARAYPYAFDV WGQGTLVTVSS

SEQ ID NO:26：EIVLTQSPATLSVSPGETATLSCRASQSVRNDLAWYQQKPGQAPRLLI YGASTRASGIPARFSGSGSGTEFTLTISSLQSEDFAIYYCQQYKDWPPWTFGQGTKVEIK

SEQ ID NO:27：QVQLVQSGAEVKKPGSSVKVSCKSSGGTFSDYAINWVRQAPGQGL EWMGRILPIVGVPNYAQKFQGRVTITADKSSSTAYKEVSGLRSEDTAVYYCARRSGINGHGL DVWGQGTTVIVSS

SEQ ID NO:28：DIVMTQSPLSLPVTPGEPASISCRSSQSLLNTNGYNYLEWYLHKPGQ SPQLLIYLGSHRASGVPDRFSGSGSGTDFTLKISRAEPEDVGVYYCMQTLQTQGYTFGQGT KLEIK

SEQ ID NO:29：QVQLQQSGAELAKPGASVKMSCKASGYTFTSYWMHWVKQRPGQG LEWIGYINPSTGYTEYNQKFKDKATLTADKSSSTAYMQLSSLTSEDSAVYYCTRSDSTNYLF VYWGQGTLVTVSS

SEQ ID NO:30：DIVMSQSPSSLAVSAGEKVTMRCKSSQSLLNSRTRKNHLAWYQQKP GQSPTLLIYWASTRESGVPDRFTGSGSGTDFTLTISSVQAEDLAVYYCKQSYNLMYTFGGG TKLEIK

SEQ ID NO:31：QVQLQQSGAEVAKPGASVRMSCKASGYIFTRYWMHWVKQRPGQG LEWIGYINPSTGYTEYNQKFKDKAALTADKSSGTAYMQLSSLTSEDSAVYYCARSDYTNYV FEYWGQGTLVTVSS

SEQ ID NO:32：DVVMTQTPLSLPVSLGDHASISCRSSQSLVHSNGNTYLHWSLQKPG QSPKLLIFKVSNRFSGVPDRFSGSGSGTDFTLKISRVEAEDLGVYFCSQSTHVPYTFGGGTEL EIK

SEQ ID NO:33：ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALT SGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKRVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK

SEQ ID NO:34：RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNA LQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGECS。

Detailed Description

The present invention will be further described in detail below with reference to specific embodiments and with reference to the accompanying drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent.

Example 1: isolation of MPXV B6 protein-specific memory B cells

In volunteersWith informed consent, approximately 15mL of blood was collected and PBMCs were isolated by centrifugation using lymphocyte separation tubes (available from Daidae). Isolated PBMCs were incubated with MPXV B6 protein (400 nM final concentration) on ice for 30min, then washed 2 times with PBS, and incubated with the following antibodies (from BD or Miltenyi): anti-human CD3/PE-Cy5, anti-human CD16/PE-Cy5, anti-human CD235a/PE-Cy5, anti-human CD19/APC-Cy7, anti-human CD27/Pacific Blue, anti-human IgG/FITC, and anti-His/PE. After incubation with antibody on ice for 30min, wash with PBS 2 times and transfer into flow tubes. Sorting by FACSAria III, collecting PE-Cy5 ^- APC-Cy7 ⁺ Pacific Blue ⁺ FITC ⁺ PE ⁺ I.e. antigen-specific binding memory B cells, were collected directly into 96-well plates, 1 cell per well.

Example 2: single memory B cell BCR sequence amplification and IgG total antibody expression vector construction

The memory B cells obtained in example 1 were reverse transcribed by thermostable M-MVL reverse transcriptase (purchased from Beijing Jialan) while template switching and ligation were performed by TSO primers at 42℃for 90min; then 50 ℃,2min,42 ℃,2min and 10 cycles; 70 ℃ for 15min; cDNA was obtained.

The reverse transcription product cDNA was used as a template for enrichment by dsDNA amplification using the HotStar Tap Plus enzyme (QIAgen). The reaction conditions were as follows: 95 ℃ for 5min;95 ℃,30s,60 ℃,30s,72 ℃ and 90s;30 cycles; 72℃for 10min.

Using the PCR product as a template, the variable region sequence of the antibody was amplified specifically by nested PCR, and the first round of PCR (PCRa) reaction conditions were as follows: 95 ℃ for 5min;95 ℃,30s,55 ℃ (H chain/kappa chain) or 50 ℃ (lambda chain), 30s,72 ℃,90s,35 cycles; 72℃for 7min. This product was used as template and subjected to a second round of PCR (PCRb) under the following reaction conditions: 95 ℃ for 5min;95 ℃,30s,58 ℃ (H chain) or 60 ℃ (kappa chain) or 64 ℃ (lambda chain), 30s,72 ℃,90s,35 cycles; PCR products were obtained at 72℃for 7min.

The PCR products were separated by electrophoresis on a 1.2% agarose gel, and the cut gel with a band size of 400bp was recovered and sequenced. The sequences measured were analyzed using IgBlast or IMGT online websites.

And (3) connecting the variable region sequence of the antibody obtained by analysis with the constant region of the corresponding heavy chain/light chain through homologous recombination, and cloning the variable region sequence into an expression vector pCAGGS (laboratory preservation) to obtain the IgG full-antibody light and heavy chain recombinant expression plasmid. And (3) carrying out cotransfection of the antibody light and heavy chain plasmids on HEK293T cells to express the antibody, purifying the protein by a protein A affinity chromatography column and a molecular sieve chromatography column in sequence, and carrying out SDS-PAGE identification to obtain the high-purity antibody protein.

Wherein, the amino acid sequence of the D21 heavy chain variable region is shown as SEQ ID NO. 25, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 26 after sequencing; the amino acid sequence of the heavy chain variable region of D68 is shown as SEQ ID NO. 27, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 28.

The three complementarity determining regions CDRs of the D21 heavy chain variable region were analyzed to have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 1, CDR2 as shown in SEQ ID NO. 2, and CDR3 as shown in SEQ ID NO. 3; the three complementarity determining region CDRs of the D21 light chain variable region have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 4, CDR2 as shown in SEQ ID NO. 5, and CDR3 as shown in SEQ ID NO. 6.

The three complementarity determining region CDRs of the D68 heavy chain variable region have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 7, CDR2 as shown in SEQ ID NO. 8, and CDR3 as shown in SEQ ID NO. 9; the three complementarity determining region CDRs of the D68 light chain variable region have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 10, CDR2 as shown in SEQ ID NO. 11, and CDR3 as shown in SEQ ID NO. 12.

Example 3: isolation of MPXV M1 protein-specific B cells, 10 Xgenomic sequencing and construction of IgG full-antibody expression vector

The lymph nodes of the vaccinated monkey pox mRNA vaccine and the surviving challenge mice were collected, ground to form a single cell suspension, added with the monkey pox virus M1 antigen protein at a final concentration of 400nM for incubation with the cells, placed on ice for 30min, washed twice with PBS, stained with antibodies including Anti-mouse CD138/APC, anti-mouse CD93/APC, anti-mouse CD38/PE-Cy7, anti-mouse IgD/BV510, anti-mouse GL-7/FITC, anti-mouse B220/BV421 and Anti-His/PE, incubated for 30min on ice in the absence of light, and after washing twice with PBS, the cells were transferred to the flow tube. Cell populations of CD93-CD138-CD38-/+ IgD-GL-7+ B220+ His+ cell populations were sorted into flow tubes using a flow sorter BDAria III, and immediately after sorting, a 10 XGenomics single cell sequencing procedure (completed by Co.). After obtaining the antibody sequences, the variable region locus characteristics of the antibody were first analyzed, the variable region sequences of the antibody were synthesized and ligated to the constant regions of IgG1/igκ/igλ to form the complete antibody expression plasmid (pCAGGS vector). And (3) carrying out cotransfection of the antibody light and heavy chain plasmids on HEK293T cells to express the antibody, purifying the protein by a protein A affinity chromatography column and a molecular sieve chromatography column in sequence, and carrying out SDS-PAGE identification to obtain the high-purity antibody protein.

Wherein, the amino acid sequence of the 39# heavy chain variable region is shown as SEQ ID NO. 29, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 30 after sequencing; the amino acid sequence of the 40# heavy chain variable region is shown as SEQ ID NO. 31, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 32.

The three complementarity determining region CDRs of the 39# heavy chain variable region were analyzed to have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 13, CDR2 as shown in SEQ ID NO. 14, and CDR3 as shown in SEQ ID NO. 15; the three complementarity determining region CDRs of the 39# light chain variable region have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 16, CDR2 as shown in SEQ ID NO. 17, and CDR3 as shown in SEQ ID NO. 18.

The three complementarity determining region CDRs of the 40# heavy chain variable region have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 19, CDR2 as shown in SEQ ID NO. 20, and CDR3 as shown in SEQ ID NO. 21; the three complementarity determining region CDRs of the 40# light chain variable region have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 22, CDR2 as shown in SEQ ID NO. 23, and CDR3 as shown in SEQ ID NO. 24.

Example 4: surface Plasmon Resonance (SPR) technology for detecting ability of antibody to bind antigen

Surface plasmon resonance analysis was performed using Biacore 8K (GE Healthcare). The method comprises the following specific steps:

protein A chip (GE Healthcare) is selected, antibody protein is fixed on the chip through combination of protein A and antibody Fc, the fixed amount of the antibody is about 500RU, the antigen protein is diluted by the ratio of PBST solution (pH 7.4), the sample flows through the surface of the chip, and the change of the response value is recorded. Kinetic profile analysis of antibody binding antigen was performed using BIAevaluation software 8K (GE Healthcare) software, as shown in fig. 1-4, and the kinetic constants of antibody binding antigen are shown in tables 1 and 2 below. The results show that the D21 and D68 antibodies have higher affinity with MPXV B6, 1.9nM and 6.2nM respectively, and that D21 is able to bind to VACV, VARV and CPXV homologous proteins in a broad spectrum with comparable ability to MPXV B6, and that D68 binds to VACV homologous proteins with comparable ability to it to MPXV B6, but with slightly reduced ability to bind to VARV and CPXV homologous proteins; the 39# antibody has a higher affinity with MPXV M1 of 1.2nM and binds VACV, VARV and CPXV with comparable or slightly higher affinity; the 40# antibody bound VACV and CPXV with higher affinity than 39#, 0.36nM and 0.17nM, respectively, and bound MPXV and CPXV without dissociation (kd <1.0 e-5). In conclusion, all four antibodies bind to the antigen with high affinity and have good broad spectrum.

Kinetic constants of binding of antibodies D21 and D68 to homologous proteins of orthopoxviruses such as MPXV B6 in Table 1

Note that: the data in the table are the mean ± standard deviation of three independent experiments.

Table 2, kinetic constants of binding of # 39 and # 40 antibodies to homologous proteins of orthopoxviruses such as MPXV M1

Example 5: plaque assay to detect neutralizing effect of antibodies on VACV virus

VACV EEV neutralization: d21 and D68 antibodies were raised from 100. Mu.g/mLStarting 3-fold ratio dilution, and diluting 10 gradients altogether; adding complement to each diluted antibody dilution; adding an antibody for blocking IMV to each antibody dilution; adding diluted virus solution (about 120 PFU/well) to each well; placing the mixed solution in a 37 ℃ incubator for incubation for 2 hours; adding the incubated antibody and virus mixed solution into cells, and infecting the cells for 1h at 37 ℃; the mixture was discarded, cells were washed once with PBS per well, then 1mL (2 XDMEM/carboxymethylcellulose 1:1 mixture) was added, and incubation was continued for 48h; adding 4% paraformaldehyde fixing solution into each hole, and fixing for more than 2 hours; removing paraformaldehyde, adding crystal violet dye liquor into each hole, and observing a result after dyeing for 2 hours; the neutralization activity value (PRNT) of the antibody was calculated based on the number of plaques ₅₀ ). As shown in FIG. 5, the antibodies D21 and D68 can efficiently neutralize VACV virus infection, the activities are respectively 0.075 mug/mL and 0.06 mug/mL, and the broad spectrum characteristics of the antibodies indicate that the antibodies can well neutralize other orthopoxvirus infection such as monkey pox virus.

VACV IMV neutralization: the 39# and 40# antibodies were diluted 2-fold from 100 μg/mL for 10 gradients total; adding diluted virus solution (about 120 PFU/well) to each well; placing the mixed solution in a 37 ℃ incubator for incubation for 2 hours; adding the incubated antibody and virus mixed solution into cells, and infecting the cells for 1h at 37 ℃; the mixture was discarded, cells were washed once with PBS per well, then 1mL (2 XDMEM/carboxymethylcellulose 1:1 mixture) was added, and incubation was continued for 48h; adding 4% paraformaldehyde fixing solution into each hole, and fixing for more than 2 hours; removing paraformaldehyde, adding crystal violet dye liquor into each hole, and observing a result after dyeing for 2 hours; the neutralization activity value (PRNT) of the antibody was calculated based on the number of plaques ₅₀ ). As shown in FIG. 6, it was found that antibodies 39# and 40# were able to neutralize VACV virus infection with high efficiency, the activities were 0.075. Mu.g/mL and 0.06. Mu.g/mL, respectively, and according to the broad-spectrum properties of the antibodies, they were also able to neutralize other orthopoxviruses such as monkey pox virus.

Claims

1. A neutralizing antibody against the B6 antigen (a) or the M1 antigen (B) of the monkey pox virus,

(a) Neutralizing antibodies against the monkey poxvirus B6 antigen, preferably, the three complementarity determining region CDRs of the heavy chain variable region thereof have an amino acid sequence selected from the group consisting of: CDR1 as shown in SEQ ID NO. 1, CDR2 as shown in SEQ ID NO. 2, and CDR3 as shown in SEQ ID NO. 3; the three complementarity determining region CDRs of the light chain variable region thereof have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 4, CDR2 as shown in SEQ ID NO. 5, and CDR3 as shown in SEQ ID NO. 6;

alternatively, the three complementarity determining region CDRs of the heavy chain variable region thereof have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 7, CDR2 as shown in SEQ ID NO. 8, and CDR3 as shown in SEQ ID NO. 9; the three complementarity determining region CDRs of the light chain variable region thereof have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 10, CDR2 as shown in SEQ ID NO. 11, and CDR3 as shown in SEQ ID NO. 12;

(b) Neutralizing antibodies against the monkey poxvirus M1 antigen, preferably, the three complementarity determining region CDRs of the heavy chain variable region thereof have an amino acid sequence selected from the group consisting of: CDR1 as shown in SEQ ID NO. 13, CDR2 as shown in SEQ ID NO. 14, and CDR3 as shown in SEQ ID NO. 15; the three complementarity determining region CDRs of the light chain variable region thereof have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 16, CDR2 as shown in SEQ ID NO. 17, and CDR3 as shown in SEQ ID NO. 18;

alternatively, the three complementarity determining region CDRs of the heavy chain variable region thereof have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 19, CDR2 as shown in SEQ ID NO. 20, and CDR3 as shown in SEQ ID NO. 21; the three complementarity determining region CDRs of the light chain variable region thereof have amino acid sequences selected from the group consisting of: CDR1 as shown in SEQ ID NO. 22, CDR2 as shown in SEQ ID NO. 23, and CDR3 as shown in SEQ ID NO. 24.

2. The monkey poxvirus neutralizing antibody or antigen-binding fragment thereof according to claim 1, wherein the antibody against the monkey poxvirus B6 antigen comprises a heavy chain variable region as shown in SEQ ID No. 25 and a light chain variable region as shown in SEQ ID No. 26;

alternatively, it comprises a heavy chain variable region as set forth in SEQ ID NO. 27 and a light chain variable region as set forth in SEQ ID NO. 28;

the antibody against the monkey pox virus M1 antigen comprises a heavy chain variable region as shown in SEQ ID NO. 29 and a light chain variable region as shown in SEQ ID NO. 30;

alternatively, it contains a heavy chain variable region as shown in SEQ ID NO. 31 and a light chain variable region as shown in SEQ ID NO. 32.

3. The monkey poxvirus neutralizing antibody or antigen binding fragment thereof according to claim 1 or 2, wherein the antibody type is IgG1, igG2, igG3, igG4, igA, igM, igE or IgD;

preferably, the antibody or antigen binding fragment thereof removes CDR regions, and the remaining sequence-derived species include, but are not limited to, one or more of mouse, rat, guinea pig, hamster, rabbit, ferret, cat, dog, goat, sheep, cow, pig, horse, monkey, and human;

preferably, the antibody further comprises a heavy chain constant region and a light chain constant region;

preferably, the antibody comprises the sequence of the constant region of one of the human antibodies IgG1, igG2, igG3, igG4, igA, igM, igE or IgD;

preferably, the amino acid sequence of the heavy chain constant region of the antibody is shown in SEQ ID NO. 33;

preferably, the amino acid sequence of the light chain constant region of the antibody is shown in SEQ ID NO. 34.

4. A monkey poxvirus neutralizing antibody or antigen binding fragment thereof according to any one of claims 1 to 3, characterised in that it is a Fab, fab '-SH, fv, scFv, F (ab') 2, diabody, antibody composition.

5. A polynucleotide encoding the monkey poxvirus neutralizing antibody or antigen binding fragment thereof of any one of claims 1 to 4.

6. An expression vector comprising the polynucleotide of claim 5.

7. A host cell comprising the expression vector of claim 6.

8. Use of a monkey poxvirus neutralizing antibody or antigen binding fragment thereof according to any one of claims 1 to 4 in the manufacture of a medicament for the treatment and prevention of an orthopoxvirus infection, in particular an orthopoxvirus including but not limited to a monkey poxvirus, a vaccinia virus, a smallpox virus, a vaccinia virus.

9. A pharmaceutical composition comprising the monkey poxvirus neutralizing antibody or antigen binding fragment thereof according to any one of claims 1 to 4 and a pharmaceutically acceptable carrier, optionally further comprising excipients.

10. The pharmaceutical composition of claim 9, wherein the pharmaceutical composition is in a dosage form that is an oral or non-oral dosage form; more specifically, the oral agent is a tablet, a powder, a pill, a powder, a granule, a fine granule, a soft/hard capsule, a film coating agent, a pellet, a sublingual tablet, a paste, or the like; the non-oral preparation is injection, suppository, transdermal preparation, ointment, plaster, topical liquid, etc.