Fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin and its application

Abstract

The present invention discloses a fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin and its application. The amino acid sequences of the variable regions CDR1, CDR2, and CDR3 of the antibody heavy chain are shown as SEQ ID NO.1, SEQ ID NO.2, and SEQ ID NO.3; the amino acid sequences of the CDR1, CDR2, and CDR3 of the light chain variable region are shown as SEQ ID NO.4, SNN, and SEQ ID NO.6. The antibody can specifically bind to Staphylococcus aureus α-hemolysin or free α-hemolysin, and can be used for treating, preventing, or diagnosing Staphylococcus aureus infections, etc., and will become an important research direction in the field of "non-antibiotic" treatment of methicillin-resistant Staphylococcus aureus infections and controlling the development of drug resistance.

Description

Technical Field

[0001] The present invention relates to the field of antibodies, in particular to a fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin, and also to applications of the antibody. Background Art

[0002] Staphylococcus aureus is a versatile pathogen and a common cause of hospital-acquired and community-acquired infections. While most S. aureus infections manifest as skin and soft tissue infections, the pathogen can also cause more invasive and life-threatening conditions such as sepsis, endocarditis, and pneumonia. The emergence and spread of multidrug-resistant strains, particularly methicillin-resistant S. aureus (MRSA), in hospitals and the community has made therapeutic intervention increasingly difficult and expensive. Currently, MRSA infection has become one of the most common nosocomial pathogens worldwide, affecting ICU wards, postoperative infections, burns, and combat trauma. Given the scarcity of newly developed antibiotics, considerable interest and effort has been devoted to exploring active and passive immune-mediated therapies to prevent and treat S. aureus infections.

[0003] Staphylococcus aureus possesses a robust arsenal of virulence factors, representing potential targets for both active and passive immunotherapy. Alpha-toxin is one of the earliest identified and best-studied pore-forming toxins in S. aureus. At low concentrations, the toxin induces the production of proinflammatory mediators and promotes epithelial barrier disruption, at least in part by binding and activating ADAM10, leading to cleavage of E-cadherin and disruption of intercellular adherens junctions. At high concentrations, alpha-toxin forms complexes that form pores in susceptible host cell membranes, leading to disruption of ion gradients, loss of membrane integrity, and direct lysis. Fully assembled alpha-toxin forms a heptameric pore, with each monomer donating two β-strands to form a transmembrane β-barrel.

[0004] Currently, there is no specific drug treatment for α-toxin-related symptoms. Research has proposed a variety of treatments, including small molecule inhibitors targeting its receptor, vaccines, or monoclonal or polyclonal antibodies targeting α-toxin. The antibodies of the present invention were evaluated for their protective effects in lethal models of Staphylococcus aureus sepsis and Staphylococcus aureus pneumonia. The experimental results showed that in the sepsis model, 800 μg of the antibody protected 70% of mice, and 400 μg protected 40% of mice. In the pneumonia model, 800 μg of the antibody protected 80% of mice, and 400 μg protected 50% of mice. These results indicate that fully human anti-Staphylococcus aureus α-toxin antibodies can inhibit disease progression, enhance clearance, and inhibit the systemic spread of bacteria or related toxins, effectively protecting BALB / C mice from sepsis and pneumonia caused by MRSA infection. Therefore, passive immunotherapy for MRSA infection, centered around antibody drugs, has great potential for development and application, and may become a new immunotherapy approach for the "non-antibiotic" treatment of MRSA infection and the control of drug resistance. Summary of the Invention

[0005] In view of this, one of the objects of the present invention is to provide a fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin; a second object of the present invention is to provide a nucleotide sequence encoding the fully human Hla monoclonal antibody; a third object of the present invention is to provide a vector or host cell containing the nucleotide sequence; a fourth object of the present invention is to provide a method for producing a fully human Hla monoclonal antibody; a fifth object of the present invention is to provide the use of the fully human Hla monoclonal antibody in the preparation of a reagent that specifically binds to Staphylococcus aureus α-hemolysin or free α-hemolysin; and a sixth object of the present invention is to provide the use of the fully human Hla monoclonal antibody in the preparation of a drug for treating, preventing or diagnosing Staphylococcus aureus infection.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] 1. A fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin, the fully human Hla monoclonal antibody comprising a heavy chain and a light chain, the amino acid sequences of the variable regions CDR1, CDR2, and CDR3 of the heavy chain being shown in SEQ ID NO.1, SEQ ID NO.2, and SEQ ID NO.3; the amino acid sequences of the variable regions CDR1, CDR2, and CDR3 of the light chain being shown in SEQ ID NO.4, SNN, and SEQ ID NO.5.

[0008] Preferably, the constant region of the antibody of the present invention includes any one of the human IgA, IgD, IgE, IgG or IgM constant regions, preferably IgG1 in IgG; and or, an antibody comprising but not limited to or consisting of a VL / VH region pair and an antibody constant domain, such as scFv, Fab, F(ab′)2 or Fv specific antibodies, etc.

[0009] Preferably, the amino acid sequence of the heavy chain is shown in SEQ ID NO.6; the amino acid sequence of the light chain is shown in SEQ ID NO.7.

[0010] Preferably, the fully human Hla monoclonal antibody specifically binds to Staphylococcus aureus α-hemolysin or a Staphylococcus aureus α-hemolysin mutant; the amino acid sequence of the Staphylococcus aureus α-hemolysin is shown in SEQ ID NO.10; and the sequence of the Staphylococcus aureus α-hemolysin mutant is shown in SEQ ID NO.11.

[0011] Preferably, the equilibrium dissociation constant of the fully human Hla monoclonal antibody binding to α-hemolysin is no more than 1×10 -8 M, such as 1×10 -9 M, 1×10 -10 M, 1×10 -11 M or dissociates from Staphylococcus aureus α-hemolysin with a smaller KD. The term "KD" refers to the equilibrium dissociation constant of a specific antigen-antibody interaction, indicating the degree of dissociation between the antibody and antigen at equilibrium. A smaller KD indicates less dissociation, indicating a stronger affinity between the antibody and antigen.

[0012] In the present invention, humanized monoclonal antibodies are produced from blood lymphocytes severely infected with Staphylococcus aureus, and thus naturally purified and selected antibodies with high affinity are generated to achieve neutralization and effective protection against infection.

[0013] 2. The nucleotide sequence encoding the fully human Hla monoclonal antibody.

[0014] 3. A vector or host cell containing the nucleotide sequence; the host cell may be yeast cells, sf9 insect cells, CHO cells, HEK293 cells, etc., and a human production cell line is particularly preferred, preferably HEK293F cells.

[0015] 4. A method for producing a fully human Hla monoclonal antibody, wherein the antibody comprises a heavy chain and a light chain, and is obtained by culturing a host cell containing a nucleotide sequence encoding the antibody, collecting the expressed antibody, and isolating and purifying the antibody using Protein A / G; the nucleotide sequence encoding the antibody is shown in SEQ ID NO. 11.

[0016] 5. Use of the fully human Hla monoclonal antibody in the preparation of a reagent that specifically binds to Staphylococcus aureus α-hemolysin or free α-hemolysin.

[0017] 6. Use of the fully human Hla monoclonal antibody in the preparation of a medicament for treating, preventing or diagnosing Staphylococcus aureus infection.

[0018] The beneficial effects of the present invention are as follows: the present invention discloses a fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin, the antibody is produced by culturing a host cell into which an expression vector having a signal sequence is transferred, the produced monoclonal antibody is secreted into the supernatant, and can be separated and purified by applying conventional chromatography technology, preferably using Protein A / G for separation and purification, the prepared antibody can be used for diagnosis or determination of α-hemolysin, and is effective, and the antibody can also prevent or treat sepsis and pneumonia caused by MRSA infection, and is of great significance for the prevention, treatment and detection of Staphylococcus aureus. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration:

[0020] Figure 1 This is a diagram of single plasma cell sorting.

[0021] Figure 2 This is the SDS-PAGE test result of fully human anti-Hla antibody.

[0022] Figure 3 This is an analysis of the binding activity of the fully human anti-Hla antibody M0399 to wHla.

[0023] Figure 4 The results of antigen-antibody interaction analysis were analyzed using biomembrane interferometry technology.

[0024] Figure 5 This is the result of Western Blot on Hla denatured gel.

[0025] Figure 6 Evaluation of experimental results for alpha-toxin animal models.

[0026] Figure 7 To establish and protect the lethal model of MRSA sepsis infection.

[0027] Figure 8 To establish a lethal model of MRSA pneumonia infection and its protectiveness. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0029] Example 1, wild-type Staphylococcus aureus α-toxin (wHla) and mutant Staphylococcus aureus α-toxin (Hla H35L ) expression and purification

[0030] The wHla gene was amplified by PCR from genomic DNA of Staphylococcus aureus strain (ATCC accession number BAA-1556). The H35L variant was then generated by site-directed mutagenesis of the wild-type gene using the QuickChange II XL site-directed mutagenesis kit. After confirmation by DNA sequencing, it was expressed in Escherichia coli, cultured overnight at 37°C in LB medium containing ampicillin, and the cells were harvested by centrifugation. The wHla protein and Hla were purified using Ni-NTA. H35L Protein, the amino acid sequence of wHla protein is shown in SEQ ID NO.10, Hla H35L The amino acid sequence of the protein is shown in SEQ ID NO.11.

[0031] Example 2: Isolation of peripheral blood mononuclear cells (PBMC)

[0032] Healthy volunteers and volunteers who recovered from severe Staphylococcus aureus infection were recruited, and venous blood samples were collected in anticoagulant tubes containing heparin. PBMC cells were isolated by density centrifugation as follows: venous blood was collected and centrifuged at 22°C, 400×g for 15 minutes; the upper transparent plasma layer after centrifugation was aspirated and frozen at -80°C; the supernatant was aspirated and thoroughly mixed with an equal amount of RPMI1640 (Gibco), and then slowly added to a sterile centrifuge tube containing lymphocyte separation medium, keeping the liquid surface layer intact, and centrifuged at 2000rpm for 20 minutes. The mononuclear cells in the cloud layer were aspirated into a sterile centrifuge tube, and more than 5 times the volume of RPMI1640 was added, and the cells were centrifuged at 1500rpm for 10 minutes. The cells were washed twice and resuspended in an appropriate amount of RPMI1640 at a concentration of 1×10 7 / Stay frozen in liquid nitrogen until use.

[0033] Example 3: Flow cytometry sorting of single plasma cells

[0034] Flow cytometry sorting of single plasma cells: Using Hla protective antigen protein (HPLC purity> 95%) as the antigen, the serum was tested by ELISA to determine the antibody titer of the sample. Samples with high antibody titers were selected and single plasma cells were sorted by flow cytometry. Plasma cell populations at different time points were separated by gate sorting based on CD3 / CD14 / CD16 / CD235a-CD19+CD20+ / -CD38hiCD27hi. Through serological experiments and B lymphocyte phenotype analysis, we can ensure that we can obtain a large number of single plasma cells from > 3% of the plasma cell population and isolate the gene sequence of the fully human monoclonal antibody against Hla from them. The heavy chain nucleotide sequence is shown in SEQ ID NO.8, and the light chain nucleotide sequence is shown in SEQ ID NO.9. The number of cells sorted is large and in good condition ( Figure 1 ).

[0035] Example 4. Cloning of anti-Hla antibodies and expression of fully human antibodies

[0036] The first strand of cDNA was synthesized using Superscript V reverse transcriptase (Invitrogen, Carlsbad, CA) and random primers. Human Ig V was amplified by PCR using an Ig primer set (heavy chain constant region primer sequence: 5'-gcggccctgggctgcctggtcaag-3'; light chain constant region primer sequence: 5'-aggagagtgtcacagagcaggacag-3'). H and V K / L , the amplified V H and V K / L The product was cloned into a TOPO TA vector and sequenced. The amplified product was then re-amplified by PCR and identified by electrophoresis on a 1.2% agarose gel.

[0037] Antibody gene sequence determination and bioinformatics analysis: Antibody gene PCR products that were positive by gel electrophoresis and had matching heavy and light chains were purified using the Qiagen PCR product purification kit and sequenced from both the forward and reverse directions. The antibody gene family, mutation rate, subtype, and CDR region were analyzed using the IMGT online server (http: / / imgt.cines.fr / ). New antibody genes were entered into the antibody gene library.

[0038] The PCR products of the antibody variable region genes that were positive by gel electrophoresis and whose heavy and light chains could be matched were ligated to the pcDNA3.3 vector using the TA cloning method to construct an expression vector for a fully human anti-Hla antibody. The expression vector was then transformed into DH5α competent cells and cultured overnight at 37°C on a plate containing ampicillin resistance. Ten single colonies were picked and PCR was performed using specific primers. The reaction conditions were as follows: pre-denaturation at 94°C for 3 minutes; denaturation at 94°C for 30 seconds, annealing at 55°C for 30 seconds, and extension at 72°C for 100 seconds, for 28 cycles; extension at 72°C for 5 minutes, and 5 μL of PCR product was detected by 1% agarose gel electrophoresis.

[0039] The results showed that transformants containing antibody heavy and light chain genes were identified among the positive transformants.

[0040] Example 5. Expression and purification of fully human anti-Hla antibodies

[0041] The vector plasmid in the positive transformant obtained in Example 4 was transformed into DH5α competent cells and amplified in large quantities. After a large amount of recombinant plasmid was extracted, Ig V H 、V K / L HEK293F cells were co-transfected with the transfection reagent polyethyleneimine (PEI) and cultured in OPM medium at 37°C in a 5% CO2 incubator for 120 h. The transfection supernatant was collected by centrifugation at 4°C and 3000×g for 30 minutes and purified by Protein A affinity chromatography. The expression and purification of the antibody were verified by SDS-PAGE. Figure 2 ) showed that the transfected cells successfully expressed the antibody, which was named fully human Hla monoclonal antibody M0399, abbreviated as M0399 antibody or M0399 monoclonal antibody, and the relative molecular weight of the antibody was approximately 150-180KD, the heavy chain was approximately 52KD, and the light chain was approximately 25KD; the heavy chain amino acid sequence was shown in SEQ ID NO.6, wherein the amino acid sequences of the heavy chain variable region CDR1, CDR2, and CDR3 were shown in SEQ ID NO.1, SEQ ID NO.2, and SEQ ID NO.3; the light chain amino acid sequence was shown in SEQ ID NO.7, and the light chain variable region CDR1, CDR2, and CDR3 amino acid sequences were shown in SEQ ID NO.4, SNN, and SEQ ID NO.5.

[0042] Example 6. Binding activity detection of expressed antibodies

[0043] ELISA plates were coated with wild-type wHla as the antigen at 100 μL / well, incubated at 4°C overnight, and blocked with blocking buffer at 37°C for 2 h. A stock solution of the antibody (primary antibody) expressed by overlapping PCR transfection was added. Positive controls included a stock solution of a positive plasma sample (1:50 dilution) and the M0399 antibody (1:1000 dilution). Negative controls included a stock solution of a negative plasma sample (1:50 dilution) and an irrelevant negative control antibody, IgG1, at 0.5 μg / mL. Blank plates were then incubated with blocking buffer at 100 μL per well in triplicate at 37°C for 1 h.

[0044] Wash the plate once with PBST buffer (4 cycles), add 1:5000 diluted Anti-Human HRP-IgG secondary antibody, 100 μL / well, and incubate at 37°C for 40 min. Wash the plate once with PBST buffer (4 cycles), protect from light, add TMB color development solution 100 μL / well, develop at 37°C in the dark for 5 min, add 2M stop solution 50 μL / well to terminate the reaction, and the OD 450nm Detect the absorbance value at 400 nm. Calculate the mean of the negative control irrelevant antibody IgG1 and the threshold value (3 times the mean value). A value greater than the threshold value is considered positive.

[0045] The experiment showed that the fully human Hla monoclonal antibody M0399 can bind to wHla ( Figure 3 ), and EC50 were 0.00609 μg / mL (Table 1).

[0046] Table 1. EC50 of M0399 and wHla

[0047]

[0048]

[0049] Example 7: Determination of Antibody-Antigen Affinity by Biofilm Interferometry (BLI)

[0050] The kinetic parameters of M0399 and wHla were measured using biofilm interferometry. 50 nM of the isolated M0399 monoclonal antibody was immobilized on the AHC sensor. Two-fold serial dilutions of wHla (31.3 nM to 500 nM) were loaded according to the sample plate arrangement. The procedure was performed according to the "baseline test - loading test - quenching - quenching - plate washing - baseline test - binding test - dissociation test" setting. The association rate constant (kon), dissociation rate constant (kdis), and equilibrium dissociation constant (KD) were calculated. The results are shown in Table 2. The KD of M0399 and wHla was 5.34×10 -9 M( Figure 4 ).

[0051] Table 2. Binding kinetics data of M0399 and wHla

[0052] Ag KD(M) Kon(1 / Ms) Kdis(1 / s) wHl <![CDATA[5.34×10 -9 ]]> <![CDATA[2.15×10 5 ]]> <![CDATA[1.15×10 -3 ]]>

[0053] Example 8: Determination of M0399 Antibody Epitope Type

[0054] Protein sample preparation: Add 10 μg of wHla sample to 5 μL of reducing loading buffer and boil in a boiling water bath for 5 minutes. Assemble the electrophoresis tank and precast gel, add running buffer, and remove the comb before loading the sample. Set the electrophoresis instrument voltage to 120 V and run the electrophoresis. Terminate the electrophoresis when the bromophenol blue reaches 1 cm from the bottom edge. Remove the electrophoresis gel and rinse it with clean water. Transfer the gel to a semi-dry electroporator and set the voltage to 22 V for 23 minutes. After transfer, block the PVDF membrane in TBST containing 5% skim milk powder overnight at 4°C. Wash the membrane three times with TBST for 5 minutes each time. Add 1 μg / mL M0399 solution and incubate at 37°C for 1 hour. After washing the membrane three times, add a 1:5000 dilution of anti-human HRP-IgG (secondary antibody) and incubate at 37°C for 40 minutes.

[0055] The film was washed three times with TBST solution, each time for 5 min; the film was placed in a clean dish, and about 1 mL of DAB color developing solution was added dropwise in the dark. When the band was obvious, the reaction was terminated by washing with water. Figure 5 It was shown that M0399 could bind to the denatured wHla, thus judging that the epitope of the M0399 antibody was a linear epitope.

[0056] Example 9: Establishment of α-toxin lethal model and treatment evaluation

[0057] 20 mice were divided into 4 groups, 5 in each group. 100 μL of each of 2 μg wHla, 3 μg wHla, 4 μg wHla and 8 μg wHla were injected into the tail vein of each group of mice. The survival time of the mice was observed. The results are shown in the figure. Figure 6 As shown in A, 2 μg wHla can cause 100% death of mice within 72 hours, and the death trend is relatively slow. Therefore, this dose is selected as the lethal dose of the toxin model.

[0058] Twelve mice were divided into two groups, with 6 mice in each group. 2 μg wHla (100 μL / mouse) was injected into the tail vein of each group. 0.5 h later, one group was given 4 μg M0399 (100 μL / mouse) through the tail vein, and the other group was given PBS through the tail vein as a negative control. The mice were observed for 72 h and their survival was recorded. Figure 6As shown in Figure B, the protective efficacy of the M0399 antibody was 100%, meaning that within 72 hours, 4 μg of the M0399 antibody completely neutralized the toxin response elicited by 2 μg of wHla. Overall, these results demonstrate the critical role of α-toxin in S. aureus pathogenesis and provide evidence for the use of antibodies to treat diseases caused by S. aureus α-toxin, thereby limiting the severity and even death associated with S. aureus infection.

[0059] Example 10: Establishment of a lethal MRSA sepsis infection model and evaluation of protective efficacy

[0060] 25 mice were divided into 5 groups, 5 mice in each group, and 1×10 8 CFU USA300, 1.5×10 8 CFU USA300, 2.0×10 8 CFU USA300, 2.5×10 8 CFU USA300, 3.0×10 8 CFU USA300 was injected into the tail vein of each group of mice at a dose of 100 μL / mouse, and the mice were observed for 7 days and their survival was recorded. Figure 7 As shown in A, 2.0×10 8 The mortality rate of mice challenged with CFU USA300 via tail vein was 100% within 7 days, so this dose was selected as the optimal dose for the MRSA sepsis model.

[0061] Thirty mice were divided into three groups, with 10 mice in each group. The first group was administered with 800 μg of M0399 antibody through the tail vein, the second group was administered with 400 μg of M0399 antibody through the tail vein, and the third group was injected with PBS through the tail vein as a negative control. The dosage of each group was 100 μL / mouse. After 24 h, the tail vein was challenged with 2.0×10 8 CFU USA300, and observed for 7 days and recorded the survival of the mice. Figure 7 As shown in Figure B, 800 μg of M0399 antibody was able to protect 70% of mice, and 400 μg of M0399 antibody was able to protect 40% of mice. This result indicates that the M0399 antibody can resist sepsis caused by MRSA infection to a certain extent, and prevent or delay the progression of the disease to a certain extent.

[0062] Example 11: Establishment of a lethal MRSA pneumonia infection model and protective evaluation

[0063] 25 mice were divided into 5 groups, 5 mice in each group, and 1.0×10 8 CFU USA300, 2.0×10 8 CFU USA300, 4.0×108 CFU USA300, 5.0×10 8 CFU USA300, 6.0×10 8 The mice were challenged with CFU USA300 at 20 μL / mouse by tracheal intubation and observed for 7 days and the survival of the mice was recorded. Figure 8 As shown in A, 5.0×10 8 The mortality rate of mice challenged with CFU USA300 through tracheal intubation was 100% within 7 days, so this dose was selected as the optimal dose for the MRSA pneumonia model.

[0064] Thirty mice were divided into three groups, with 10 mice in each group. The first group was administered with 800 μg of M0399 antibody via tail vein, the second group was administered with 400 μg of M0399 antibody via tail vein, and the third group was injected with PBS via tail vein as a negative control. The dosage of each group was 100 μL / mouse. After 24 h, the mice were intubated and challenged with 5.0×10 8 CFU USA300, and observed for 7 days and recorded the survival of the mice. Figure 8 As shown in Figure B, 800ugM0399 antibody can protect 100% of mice, and 400ugM0399 antibody can protect 60% of mice. This result shows that M0399 antibody can resist pneumonia caused by MRSA infection to a large extent, and to a certain extent can enhance the body's clearance of invaders and inhibit their systemic spread.

[0065] The above embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin, characterized by: The fully human Hla monoclonal antibody includes a heavy chain and a light chain, and the amino acid sequences of the variable regions CDR1, CDR2, and CDR3 of the heavy chain are shown as SEQ ID NO.1, SEQ ID NO.2, and SEQ ID NO.3, respectively; the amino acid sequences of the variable regions CDR1, CDR2, and CDR3 of the light chain are shown as SEQ ID NO.4, SNN, and SEQ ID NO.5, respectively.

2. The fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin according to claim 1, characterized in that: The constant region of the antibody includes any one of human IgA, IgD, IgE, IgG or IgM constant regions.

3. The fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin according to claim 1, characterized in that: The amino acid sequence of the heavy chain is shown in SEQ ID NO.6; the amino acid sequence of the light chain is shown in SEQ ID NO.

7.

4. The fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin according to claim 1, characterized in that: The fully human Hla monoclonal antibody specifically binds to Staphylococcus aureus α-hemolysin or a mutant of Staphylococcus aureus α-hemolysin; the amino acid sequence of the Staphylococcus aureus α-hemolysin is shown in SEQ ID NO.10; The sequence of the Staphylococcus aureus α-hemolysin mutant is shown in SEQ ID NO.

11.

5. The fully human Hla monoclonal antibody against Staphylococcus aureus α-hemolysin according to claim 1, characterized in that: The equilibrium dissociation constant of the fully human Hla monoclonal antibody binding to α-hemolysin is no more than 1×10 -8 M.

6. A nucleic acid encoding the fully human Hla monoclonal antibody according to any one of claims 1 to 5.

7. A vector or host cell containing the nucleic acid according to claim 6.

8. A method for producing a fully human Hla monoclonal antibody comprising a heavy chain and a light chain, characterized in that: The host cells containing the nucleic acid sequence encoding claim 6 are cultured, the expressed antibodies are collected, and the antibodies are separated and purified by Protein A / G.

9. Use of the fully human Hla monoclonal antibody according to any one of claims 1 to 5 in the preparation of a medicament for treating or diagnosing Staphylococcus aureus infection.

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