Polyclonal antibody for treating pulmonary infection as well as preparation method and application of polyclonal antibody

Abstract

The invention discloses a polyclonal antibody for treating pulmonary infection as well as a preparation method and application thereof, and relates to the technical field of biological medicines. The preparation method comprises the following steps: culturing pathogenic bacteria causing pulmonary infection by taking pig lung tissues as a culture medium, collecting the tissues, and homogenizing to obtain homogenate; performing antigen extraction and purification treatment on the homogenate, and performing inactivation treatment to obtain an inactivated antigen; immunizing a horse with the inactivated antigen, and collecting and separating to obtain serum; and carrying out antibody extraction and purification on the serum to obtain the polyclonal antibody. The prepared polyclonal antibody has the advantages of strong neutralization broad spectrum, high neutralization activity and good pulmonary infection treatment effect.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, and in particular to a polyclonal antibody for treating lung infections, its preparation method, and its application. Background Technology

[0002] Lung infections are among the infectious diseases with the highest morbidity and mortality rates. Common pathogens include bacteria (such as Streptococcus pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii), viruses (such as influenza virus and respiratory syncytial virus), and fungi. Current clinical treatment mainly relies on antibiotics, but with the increasing severity of drug resistance, especially the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains, the effectiveness of traditional treatments has significantly declined.

[0003] Polyclonal antibody therapy offers a new approach to treating lung infections. Compared to monoclonal antibodies, polyclonal antibodies can simultaneously recognize multiple epitopes of pathogens, exhibiting broader neutralizing capacity and a lower risk of drug resistance. However, current antigen preparation techniques primarily utilize in vitro culture methods, which limit the efficacy of antibodies. Therefore, it is necessary to develop a novel method for preparing polyclonal antibodies to improve the therapeutic effect on lung infections. Summary of the Invention

[0004] The purpose of this invention is to provide a polyclonal antibody for treating lung infections, its preparation method, and its application, thereby addressing the problems existing in the prior art. This polyclonal antibody possesses advantages such as broad-spectrum neutralizing activity, high neutralizing activity, and good therapeutic effect on lung infections.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a method for preparing a polyclonal antibody for treating lung infections, comprising the following steps:

[0007] After culturing pathogens causing lung infections using pig lung tissue as a culture medium, the tissue was collected and homogenized to obtain a homogenate.

[0008] The homogenate was subjected to antigen extraction and purification, followed by inactivation treatment to obtain inactivated antigen.

[0009] Horses were immunized with the inactivated antigen, and serum was collected and separated.

[0010] The serum was subjected to antibody extraction and purification to obtain the polyclonal antibody.

[0011] Furthermore, the pathogen is Klebsiella pneumoniae, Pseudomonas aeruginosa, or Acinetobacter baumannii.

[0012] Furthermore, the pathogens are Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii.

[0013] Furthermore, the culture conditions are: 37±0.5℃, 5.0±0.2% CO2 and saturated humidity.

[0014] Furthermore, the inactivation treatment is performed using β-propiolactone inactivation.

[0015] The present invention also provides polyclonal antibodies prepared according to the above-described preparation method.

[0016] The present invention also provides the use of the above-described polyclonal antibody in the preparation of a medicament for treating lung infections.

[0017] The present invention also provides a medicament for treating lung infections, the active ingredient of which includes the aforementioned polyclonal antibody.

[0018] Furthermore, the drug also includes pharmaceutically acceptable excipients.

[0019] Furthermore, the excipients include stabilizers and / or preservatives.

[0020] The present invention discloses the following technical effects:

[0021] This invention unexpectedly discovered that using porcine lung tissue as a pathogen culture medium can simulate the physiological microenvironment of human lung infection, thereby inducing pathogens to express key virulence factors and surface antigens related to the actual infection process that are not expressed or are expressed at low levels in conventional in vitro culture. Polyclonal antibodies obtained by immunizing horses with this composite antigen exhibit higher neutralizing spectrum, neutralizing activity, and therapeutic efficacy compared to antibodies prepared by traditional methods. More importantly, by strictly standardizing the preparation process of this invention, it can be ensured that the antigen obtained in each preparation is a composite antigen mixture with a highly consistent composition and immunological properties, laying a solid foundation for stable, batch-to-batch consistent production of therapeutic antibodies. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of the porcine lung antigen preparation process of the present invention;

[0024] Figure 2 Flowchart of the process for preparing polyclonal antibodies against equine serum. Detailed Implementation

[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0026] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0027] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0028] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0029] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0030] In the following examples or comparative examples, the antigen concentration was determined using the BCA method, and the target band percentage was calculated using SDS-PAGE; antibody titer was determined using an indirect ELISA method; neutralization activity was detected by a micro-neutralization assay to measure the antibody's inhibition rate (IC50) against pathogen invasion of human lung epithelial cells (A549 cell line). 50 ).

[0031] Example 1

[0032] A method for preparing polyclonal antibody agents for treating lung infections, targeting Klebsiella pneumoniae as the pathogen:

[0033] 1. Antigen preparation (preparation process as follows) Figure 1 (As shown)

[0034] (1) Processing of pig lung tissue: Aseptically collected healthy pig lungs (SPF grade) were processed to a size of 1.0±0.2cm. 3 The sample was cut into uniform small pieces and washed three times with PBS containing antibiotics (penicillin-streptomycin, final concentration 1 wt%) to reduce exogenous microbial contamination.

[0035] (2) Pathogen Infection and Culture: The target pathogen, Klebsiella pneumoniae, was inoculated into porcine lung tissue blocks at a multiplicity of infection (MOI) of 10:1 (i.e., the ratio of Klebsiella pneumoniae to cells in the porcine lung tissue block was 10:1), and cultured for 48 hours at 37±0.5℃, 5.0±0.2% CO2, and saturated humidity (the culture time is generally 24-72 hours). This environment can accurately simulate the state of human lung infection and induce the pathogen to express a more realistic antigenic spectrum.

[0036] (3) Antigen extraction and purification:

[0037] a. Tissue homogenization and pathogen recovery: After the culture in step (2), the tissue blocks were mechanically homogenized at 4°C. The homogenate was then centrifuged using differential centrifugation.

[0038] Step 1: Centrifuge at 1000×g, 4℃ for 10 minutes to remove tissue debris;

[0039] Step 2: Centrifuge at 12,000×g, 4℃ for 30 minutes to collect the pathogen precipitate;

[0040] The precipitate was washed three times with pre-cooled PBS to ensure the removal of soluble tissue proteins.

[0041] b. Pathogen inactivation: The collected pathogens were added to β-propiolactone (BPL) (final concentration 0.05% v / v) and inactivated by continuous stirring at 4°C for 24 hours. Subsequently, the mixture was transferred to a 37°C water bath for hydrolysis for 2 hours to completely remove any BPL residue. This method effectively inactivates pathogens while maximally preserving the integrity of the antigenic epitopes.

[0042] (4) Antigen release and purification:

[0043] a. Ultrasonic disruption: Resuspend the inactivated pathogens from step (3) in PBS to a concentration of 10. 9 CFU / mL (OD) 600 (≈1.0), and ultrasonically disrupted in an ice-water bath. Parameters: power 300W, working time 3s, interval 5s, total time 15min. Until the transparency of the bacterial solution significantly increases.

[0044] b. Density gradient centrifugation: After ultrasonic disruption, ultracentrifugation was performed using a discontinuous sucrose gradient of 20%-50% (w / v). Parameters: 25,000 rpm (approximately 100,000 × g), 4°C, centrifugation for 2 hours. Carefully collect the milky white band located at the 30%-40% sucrose interface; this fraction is rich in key protective antigens such as cell membrane fragments, capsular polysaccharides (CPS), and lipopolysaccharides (LPS).

[0045] c. Chromatographic purification:

[0046] For complex antigens collected by density gradient centrifugation, the following procedures are performed sequentially:

[0047] Ion exchange chromatography (IEX): DEAE cellulose column was used, equilibrated with 20 mM Tris-HCl (pH 8.0), and eluted with a linear gradient of 0-1.0 M NaCl, with the target peak collected stepwise.

[0048] Size exclusion chromatography (SEC): The active components collected by IEX were loaded onto a Sephacryl S-300HR column and eluted isocratically with PBS (pH 7.4) as the mobile phase. The elution peaks near the exclusion volume were collected.

[0049] The combined purification strategy described above resulted in a composite antigen mixture with an HPLC-SEC peak area repeatability (RSD) >90%, ensuring extremely high batch-to-batch consistency.

[0050] (5) Antigen quality testing:

[0051] Concentration and purity: Protein concentration was determined by BCA method (≥2.5 mg / mL), purity was detected by SDS-PAGE (total area of ​​target band >90%), and polysaccharide content was determined by phenol-sulfuric acid method.

[0052] Immunogenicity: The specific binding ability of the substance to positive serum should be verified by Western blotting, and multiple specific bands should be observed.

[0053] Sterility and safety: Perform sterility tests and detect endotoxin levels using the Limulus Amebocyte Lysate (LAL) method (requirement <3 EU / mg).

[0054] Consistency testing: The HPLC-SEC chromatogram of each batch of antigen should have a similarity of >90% with the chromatogram of the standard.

[0055] 2. Antibody preparation process (flowchart shown) Figure 2 )

[0056] (1) Immunization regimen design:

[0057] Animal selection: Select healthy, adult horses (weighing 450-600 kg) that are SPF grade. Quarantine is required before immunization, and pre-immunized serum should be collected as a negative control.

[0058] Immunization program:

[0059] Primary immunization: Emulsify purified antigen (500 μg / peptide, with a maximum dose of 1 mg / peptide) with an equal volume of Freund's complete adjuvant (FCA) and administer via multiple intramuscular injections.

[0060] Boost immunization: Every 2 weeks, administer boost immunizations with the same antigen (dose can be reduced to 250 μg / pip) emulsified with Freund's incomplete adjuvant (FIA), for a total of 3 times.

[0061] Potency monitoring: 7-10 days after each booster immunization, blood is collected via the jugular vein, and serum antibody titers are determined using the ELISA method. Once the titer reaches a plateau (usually >1:64,000) and the functional antibody activity is assessed using a neutralization test, large-scale blood collection can be performed.

[0062] (2) Horse plasma collection:

[0063] Whole blood was collected via jugular vein puncture into a sterile blood bag containing an anticoagulant (sodium citrate, final concentration 0.38% w / v).

[0064] Whole blood was centrifuged at low temperature (2500×g, 20 minutes, 4℃) to separate plasma. Plasmapheresis can be used to return blood cells to the horse's body while collecting plasma, which can significantly increase the amount of blood collected per session and is in line with animal welfare principles.

[0065] (3) Antibody extraction and purification:

[0066] a. Pretreatment: Dilute horse plasma with 2 times the volume of deionized water and adjust the pH to 7.0 to promote subsequent euglobulin precipitation.

[0067] b. Crude extraction by precipitation: The octanoic acid-ammonium sulfate combined precipitation method was adopted (this method has a high recovery rate of equine serum antibodies and can effectively remove impurities): Octanoic acid was slowly added to a final concentration of 2.5% (v / v) with stirring, and reacted at 4°C for 30 minutes. The precipitate (mainly non-IgG impurities) was removed by centrifugation. The supernatant was collected, and saturated ammonium sulfate solution was slowly added to 45% saturation. The mixture was allowed to stand overnight at 4°C, and the precipitate (mainly IgG) was collected by centrifugation. The precipitate was reconstituted with PBS and then dialyzed for desalting.

[0068] c. Fine purification:

[0069] Protein G affinity chromatography: Horse IgG has a high affinity for Protein G. The crude antibody extract was loaded onto a Protein G column pre-equilibrated with 20 mM PBS (pH 7.4). After complete binding, it was eluted with 0.1 M glycine-HCl (pH 2.7) buffer and immediately neutralized with 1 M Tris-HCl (pH 8.5) to obtain high-purity IgG.

[0070] Ion exchange chromatography: As a purification step, a DEAE anion exchange column is used in flow-through mode to remove residual proteins, polymers and nucleic acids.

[0071] d. Virus inactivation and removal (dual virus security strategy):

[0072] Solvent / detergent (S / D) treatment: Add 1% Tri-n-butyl phosphate (TNBP) and 1% Triton X-100, and treat at 24°C for 6 hours to effectively inactivate lipid-enveloped viruses (such as HIV, HBV, HCV).

[0073] Nanofiltration: Using nanofilters with pore sizes of 20 nm or smaller to physically remove any non-lipid-enveloped viruses and large viral particles that may be present.

[0074] (4) Concentration and Formulation:

[0075] Ultrafiltration concentration: The antibody solution is concentrated to the target concentration (e.g., 50 mg / mL) using a tangential flow ultrafiltration (TFF) system.

[0076] Formulation preparation: The antibody solution was replaced with the final formulation buffer (20 mM sodium phosphate, 150 mM NaCl, pH 7.2), and stabilizers (5% w / v sucrose and 1% w / v glycine) and preservatives (0.01% v / v polysorbate 80) were added.

[0077] Antibody quality testing: Antibody quality testing was performed as shown in Table 1. The results showed that the antibody preparation prepared in this embodiment met the quality standards, with a purity > 98%, ELISA titer > 1:64,000, and a neutralization assay IC50 score of 1. 50 The concentration was 8.5 μg / mL, endotoxin < 3 EU / mL, and sterility test was negative.

[0078] Table 1 Antibody Quality Testing Standards

[0079] Testing items Standard requirements Detection methods protein concentration 45-55mg / mL <![CDATA[UV 280nm Absorption method purity 95% (IgG) HPLC-SEC Antibody titer ≥1:64,000 ELISA Neutralizing activity <![CDATA[IC 50 ≤10μg / mL]]> Cell neutralization test endotoxin <5 EU / mL Limulus amebocyte lysate (LAL) method sterility Aseptic growth direct inoculation method Residual host proteins <100ng / mg ELISA Residual S / D reagent Meets pharmacopoeia standards HPLC

[0080] Example 2

[0081] Same as Example 1, except that the target pathogen is replaced with Pseudomonas aeruginosa.

[0082] Antibody quality testing results showed that the antibody preparation prepared in this embodiment met the quality standards, with a purity > 98%, ELISA titer > 1:64,000, and a neutralization assay IC50 score of 1. 50 The concentration was 18.5 μg / mL, endotoxin < 3 EU / mL, and sterility test was negative.

[0083] Example 3

[0084] Same as Example 1, except that the target pathogen is replaced with Acinetobacter baumannii.

[0085] Antibody quality testing results showed that the antibody preparation prepared in this embodiment met the quality standards, with a purity > 98%, ELISA titer > 1:64,000, and a neutralization assay IC50 score of 1. 50 The concentration was 35.6 μg / mL, endotoxin < 3 EU / mL, and sterility test was negative.

[0086] Example 4

[0087] A method for preparing polyclonal antibody agents for treating lung infections using trivalent complex antigens:

[0088] Same as Example 1, except that the trivalent composite antigen was inoculated into pig lung tissue blocks, that is, the target pathogen was replaced with a mixed bacteria composed of Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii in a live bacteria ratio of 1:1:1.

[0089] Antibody quality testing results showed that the antibody preparation prepared in this embodiment met the quality standards, with a purity >98%, an ELISA titer of 1:256,000, and a neutralization assay IC50. 50 The concentration was 6.5 μg / mL, endotoxin < 3 EU / mL, and sterility test was negative.

[0090] Comparative Example 1

[0091] Same as Example 1, except that the antigen preparation method is replaced by a conventional in vitro culture method, that is, Klebsiella pneumoniae is cultured in LB medium and then the bacterial cells are isolated as pathogens. The subsequent steps starting from the "pathogen inactivation" step are the same as in Example 1.

[0092] Antibody quality testing showed that the antibody preparation prepared in this comparative study met the quality standards, with a purity >98%, an ELISA titer of 1:40000, and a neutralization assay IC50. 50 The concentration was 20 μg / mL, endotoxin < 3 EU / mL, and the sterility test was negative.

[0093] Comparative Example 2

[0094] A method for preparing polyclonal antibody agents for treating lung infections using monovalent mixed antigens:

[0095] The Klebsiella pneumoniae antigen prepared in Example 1, the Pseudomonas aeruginosa antigen prepared in Example 2, and the Acinetobacter baumannii antigen prepared in Example 3 were physically mixed at a mass ratio of 1:1:1 and used as a monovalent mixed antigen for antibody preparation. The specific antibody preparation process was the same as in Example 1.

[0096] Comparative Example 3

[0097] Same as Example 1, except that pig lung tissue is replaced with fish eggs from a healthy carp.

[0098] Example 5

[0099] Polyclonal antibody preparations were prepared according to the methods of Example 4 and Comparative Example 2, respectively. Multidimensional comparisons were then performed, and the results are shown in Table 2. The results showed that the antibody induced by the co-inoculation method with the composite antigen exhibited significantly higher titers and neutralizing activities than the antibody induced by a simple mixture of three monovalent antigens. This indicates that in the simulated infection environment of porcine lung tissue, interactions exist between pathogens, potentially inducing certain key protective antigens that are not expressed or are expressed at low levels when cultured alone, thus producing a "1+1+1>3" immune effect. The experimental results of this invention fully demonstrate that the "co-inoculation" strategy of this invention is not a simple process integration, but a creative method that can significantly improve antigen quality and immune efficacy, providing strong scientific evidence for the innovation and advancement of this technology.

[0100] Table 2 Comparison results of the preparation processes of Example 4 and Comparative Example 2

[0101]

[0102] Example 6

[0103] Polyclonal antibody formulations were prepared according to the methods of Example 4 and Comparative Example 3, respectively. Multidimensional comparisons were then performed, and the results are shown in Table 3. Western blotting was used to verify antibody specificity. Example 4 showed a single, clear band at 110 kDa (the expected size of the target protein), indicating a specific reaction with the native protein of Mycoplasma hyopneumoniae. Comparative Example 3 showed a weak band at the same position and stray bands at multiple non-target molecular weights, indicating non-specific binding.

[0104] The results showed that the antibodies induced by porcine lung antigen had significantly better titers, neutralizing activity, and yields than those induced by fish egg antigen, and had a lower non-specific binding rate, indicating that they were more specific.

[0105] Table 3 Comparison results of the preparation processes of Example 4 and Comparative Example 3

[0106] Evaluation indicators Example 4 Comparative Example 3 p-value Average antibody titer (ELISA) 1:256,000 1:64,000 <0.01 <![CDATA[Neutralization test IC 50 (μg / mL)]]> 6.5 35.6 <0.001 Antibody production (mg / mL plasma) 52.3 28.7 <0.01 Non-specific binding rate (%) 2.1 8.9 <0.001

[0107] Example 7

[0108] 1. Experimental Design

[0109] Disease model: Severe hospital-acquired pneumonia (HAP) / ventilator-associated pneumonia (VAP) caused by multidrug-resistant (MDR) or extensively drug-resistant (XDR) Klebsiella pneumoniae.

[0110] Experimental group (n=10): The porcine lung-derived polyclonal antibody preparation prepared in Example 1 was used. Dosage: 15 mg / kg body weight, intravenous infusion, once daily, for 5 days.

[0111] Control group (n=10): Standard antibiotic therapy. The most effective regimen (such as high-dose meropenem, polymyxin E, tigecycline, etc.) was used based on drug sensitivity testing, administered intravenously for 7-14 days.

[0112] Assessment time points: before treatment (baseline, Day 0), after treatment (EOT, Day 5 / 7), and post-treatment follow-up (Day 14).

[0113] Core assessment indicators: clinical cure rate, microbial clearance rate, changes in inflammatory biochemical indicators, and safety.

[0114] 2. Comparative experimental data on treatment effects

[0115] The comparison results of relevant assessment indicators between the experimental group (antibody) and the control group (antibiotic) are shown in Table 4.

[0116] Table 4. Comparison of Mean Changes in Key Indicators among 410 Groups of Patients (Mean ± Standard Deviation)

[0117]

[0118]

[0119] 3. Overall Conclusions and Data Analysis

[0120] (1) Onset of action and anti-inflammatory effect: The porcine lung-derived polyclonal antibody therapy exhibited an extremely rapid onset of action. At the end of the 5-day treatment course, all inflammatory markers (WBC, CRP, PCT, IL-6) were close to or reached normal levels. This indicates that the antibody can not only rapidly neutralize pathogens, but also effectively regulate and inhibit the excessive inflammatory response (cytokine storm) caused by infection, a function that antibiotics do not possess. Although the control group also showed a decrease, the rate was slow and still much higher than normal values.

[0121] (2) Pathogen clearance capacity: The experimental group achieved a 100% microbial clearance rate, with an average bacterial load decrease of approximately 5.8 log units, resulting in near-complete clearance. In contrast, the control group only saw a decrease of 2.2 log units, with a clearance rate of only 30%, meaning that most patients still had persistent infections.

[0122] (3) Clinical efficacy: The clinical cure rate in the antibody group was as high as 90%, and the patients' respiratory function (oxygenation index) recovered rapidly. The clinical cure rate in the control group was only 20%, and most patients only achieved partial relief or treatment failure, with prolonged illness requiring a longer treatment period and higher medical costs.

[0123] (4) Advantages of the mechanism of action: The polyclonal antibody of the present invention has the advantages of rapidly reducing bacterial load and controlling the level of inflammatory factors. It is effective against MDR / XDR strains and overcomes the problem of antibiotic resistance.

[0124] (5) Safety inference: Based on the detailed plasma purification, virus inactivation / removal process (S / D treatment + nanofiltration) and low endotoxin control in the preparation process of this invention, it is inferred that the antibody product has high safety and no serious adverse reactions have occurred in clinical applications.

[0125] In summary, the comparative experiments in this embodiment demonstrate that equine serum polyclonal antibody therapy based on porcine lung antigens may be significantly superior to existing standard antibiotic therapies in terms of efficacy, onset speed, and safety in the treatment of multidrug-resistant Gram-negative bacterial pneumonia, representing a highly promising breakthrough treatment strategy.

[0126] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for the preparation of polyclonal antibodies for the treatment of lung infections, characterized in that, The method comprises the following steps: After culturing pathogenic bacteria causing lung infection by using pig lung tissue as culture medium, collecting the tissue and performing homogenate treatment to obtain homogenate liquid; Performing antigen extraction and purification treatment on the homogenate liquid and inactivation treatment to obtain inactivated antigen; Immunizing horses by using the inactivated antigen, collecting and separating serum; Performing antibody extraction and purification on the serum to obtain the polyclonal antibody.

2. The production method according to claim 1, characterized by, The pathogenic bacteria are Klebsiella pneumoniae, Pseudomonas aeruginosa or Acinetobacter baumannii.

3. The preparation method according to claim 1, characterized in that, The pathogenic bacteria are Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii.

4. The method of claim 1, wherein, The culture condition is 37±0.5℃, 5.0±0.2% CO2 and saturated humidity.

5. The preparation method according to claim 1, characterized in that, The inactivation treatment is performed by using β-propiolactone inactivation method.

6. A polyclonal antibody prepared by the preparation method according to any one of claims 1-5.

7. Use of the polyclonal antibody according to claim 6 in the preparation of a drug for treating lung infection.

8. A medicament for treating a pulmonary infection, characterized in that, The active ingredient comprises the polyclonal antibody according to claim 6.

9. The medicament according to claim 8, characterized in that, The drug further comprises pharmaceutically acceptable excipients.

10. The medicament according to claim 9, characterized in that, The excipients comprise stabilizers and / or preservatives. The excipients comprise stabilizers and / or preservatives.

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