CN118421571A - Chimeric VSV recombinant virus for expressing nipah virus envelope glycoprotein and application thereof - Google Patents

Abstract

The invention belongs to the field of viruses, and particularly relates to a chimeric VSV recombinant virus and application thereof; specifically discloses a chimeric VSV recombinant virus strain for coexpression of NiV G and F proteins, wherein the chimeric VSV recombinant virus strain is rVSV delta G/NiVMYGF and rVSV delta G/NiVBDGF; based on the complete virus structure, higher immunogenicity and better safety, the virus can be used as an important virus reserve resource for effective prevention and control, diagnosis and detection, vaccine preparation and antiviral treatment products in future.

Description

Chimeric VSV recombinant virus expressing Nipah virus envelope glycoprotein and its application

Technical Field

The present invention belongs to the field of viruses, and in particular relates to a chimeric VSV recombinant virus expressing Nipah virus envelope glycoprotein and an application thereof.

Background technique

Nipah disease is a serious zoonosis caused by Nipah virus (NiV). Its natural host is fruit bats, which can infect livestock such as pigs, horses, cattle and sheep, as well as pets such as dogs and cats. Pigs are the intermediate amplification hosts of NiV. NiV is listed as a biosafety level IV pathogen and a key pathogen for bioterrorism prevention. The WHO lists it as a priority pathogen in the blueprint for responding to potential pandemic risks. my country lists it as a Class I animal disease for key prevention. The mortality rate of Nipah disease is 40%-100%, causing severe respiratory failure and neurological symptoms. Pigs are extremely susceptible, with no obvious symptoms, but can excrete a large amount of toxins, which is one of the key risk factors for the spread of the disease. The disease is not pathogenic to the natural host fruit bats, but can excrete toxins outwards and spread to humans through contamination of food by body fluids and excrement. This is the main way NiV has spread in the South Asian subcontinent in recent years. It can also be transmitted between people through close contact. Since its discovery, Nipah disease has broken out almost every year in our neighboring countries such as India and Bangladesh. my country is the world's largest pig-raising country and is located on the migration route of fruit bats. Therefore, my country faces a serious threat of Nipah disease: first, there is a very high risk of imported infection, mainly due to migrating bats carrying the virus or smuggling of goods across the border; second, there is a primary risk. Studies have reported that bat sera in many provinces in my country are serologically positive for Nipah (like) viruses; two new types of henipaviruses (Mojiang virus MjoV and Langya virus LayV) have been discovered in Yunnan and Shandong, my country. The above evidence shows that henipaviruses exist in my country's natural environment, which may cause potential illness and epidemics.

NiV belongs to the Henipavirus genus of the Paramyxoviridae family. NiV is a member of the Paramyxovirinae subfamily of the Paramyxoviridae family and together with Hendra virus (HeV) constitutes the Henipavirus genus. Nipah virus contains a single-stranded RNA of about 18,000 nucleotides, which is bound to viral proteins of the replication complex (nucleoprotein (N), phosphoprotein (P), and polymerase (L)). The single-stranded RNA is surrounded by a lipid bilayer membrane containing attachment protein (G) and fusion protein (F) (Chua, 2000, Science. 288: 1432-5; Wang, et al 2001, Microbes and Infection 3, 279-287; Chan, et al 2001, J Gen Virol. 82: 2151-5).

NiV virus particles are polymorphic and have an envelope. Most of the virus particles are irregular spherical, with a diameter of about 150-200nm. A few virus particles are filamentous and can reach 10,000nm in length. NiV has two main genetic lineages: NiV Malaysia (NiV Malaysia, NiV-MY) and NiV Bangladesh (NiV Bangladesh, NiV-BD). The genome of the NiV-MY strain is 18,246 nucleotides, while the genome of the NiV-BD strain is 18,252 nucleotides. The current prevalent strain is mainly the Malaysian strain, which has 12 more bases than the HeV of the same genus, encoding at least 6 proteins such as N (nucleoprotein), P (phosphoprotein), M (matrix protein), F (fusion protein), G (receptor binding protein), and L (polymerase). Among them, the N protein, P protein, and L polymerase are collectively called the replication complex, which is bound to the viral RNA and is related to the transcription and replication of the viral genome; the M protein is involved in maintaining the morphology of the viral envelope; the F protein and G protein are involved in the fusion and adsorption of proteins and are related to viral invasion. NiV contains two membrane-anchored glycoproteins in its envelope, G protein and F protein; the G protein is 602 amino acids in total and is a type II transmembrane glycoprotein. Its N-terminus is located inside the membrane, the intramembrane part is extremely short, the hydrophobic transmembrane domain is close to the N-terminus, and the C-terminus is located outside the membrane. It consists of a "globular" head region and a longer "external stem" region. The G protein can bind to the host cell membrane proteins ephrin-B2 and ephrin-B3; the F protein is a type I transmembrane glycoprotein located on the surface of the virus particle, and its main function is to mediate the fusion of the viral envelope and the host cell membrane, thereby allowing the viral genome to enter the cell; like the G protein, the F protein is also the main immune protective antigen of the Nipah virus, which enables the immunized animals to produce neutralizing antibodies; neutralizing antibodies against the G and F proteins are the most important immune mechanism for protection against Nipah disease. When NiV invades host cells, the virus surface glycoprotein G binds to the receptor ephrin-B2/B3, which causes the G protein to activate the fusion protein F in the receptor binding region and stem region to change its conformation, thereby activating the F protein to fuse with the cell membrane, and finally the virus invades the cell. These two proteins are highly conserved on the surface of host cells, so F and G are currently the main targets for antiviral and vaccine research.

Guillaume et al. immunized hamsters with recombinant poxvirus expressing Nipah virus G or F protein and prepared hyperimmune serum. Passive immunization of hamsters with hyperimmune serum can protect them against lethal doses of Nipah virus (Guillaume V, Contamin H, Loth P, Georges-Courbot MC, Lefeuvre A, Marianneau P, Chua KB, Lam SK, Buckland R, Deubel V et al: Nipah virus: vaccination and passive protection studies in a hamster model. J Virol 2004, 78(2): 834-840.), indicating that neutralizing antibodies play an important role in the body's resistance to and elimination of Nipah virus. Kaku et al. compared the serum dilution titers of neutralization tests using Nipah virus G and F protein envelope chimeric vesicular stomatitis pseudovirions and Nipah live virus, and found that there was a positive correlation between the serum neutralization titers obtained by the two methods (Kaku Y, Noguchi A, Marsh GA, McEachern JA, OkutaniA, Hotta K, Bazartseren B, Fukushi S, Broder CC, Yamada A et al: A neutralization test for specific detection of Nipah virus antibodies using pseudotyped vesicular s tomatitis virus expressing green fluorescent protein. J Virol Methods 2009, 160(1-2): 7-13.). Patent "CN113372454B" discloses that Nipah virus receptor binding glycoprotein (G) is used as the research object, and mammalian cells are used to express it soluble, purify it, and prepare specific serum by immunizing mice. The results show that Nipah virus G protein is soluble in Expi293F cells, and the purified target protein is of the correct size and has a purity of more than 99%; the prepared antiserum can specifically bind to the target protein. Patent "HK1096431A" confirms that Nipah virus G glycoprotein causes attachment to cell receptors, while F glycoprotein induces fusion between the virus and cell membranes. G and F act synergistically to cause fusion, that is, vaccines expressing Nipah virus proteins only induce fusion when co-infected (i.e., G+F). Patent "CN102533675A" discloses a recombinant Newcastle disease virus LaSota vaccine strain expressing Nipah encephalitis virus F protein, and its preparation method and application; the Nipah virus F gene was inserted into the LaSota genome as an independent transcription unit, and the recombinant Newcastle disease virus rLa-NiVF expressing Nipah virus F protein was successfully constructed and rescued. The experimental results show that rLa-NiVF can correctly express Nipah virus F protein, and the recombinant virus maintains the high chicken embryo growth titer and high safety for mammals consistent with the LaSota vaccine strain. Patent "CN102559612B" provides a recombinant Newcastle disease virus LaSota vaccine strain expressing Nipah encephalitis virus G protein, and its preparation method and application; specifically, it discloses that the Newcastle disease virus LaSota attenuated strain was used as a vector, and reverse genetic manipulation technology was used to successfully construct a recombinant Newcastle disease virus live vector vaccine - rLa-NiVG expressing Nipah virus G protein, proving that rLa-NiVG can correctly express Nipah virus G protein, and the recombinant virus maintains the high chicken embryo growth titer consistent with LaSota and a high safety for mammals.

This application uses vesicular stomatitis virus (VSV) as a vector to construct a chimeric virus strain that co-expresses G protein and F protein, providing a new approach for the effective prevention and control, diagnosis and detection, vaccine preparation, and preparation of antiviral therapeutic products for Nipah disease.

Summary of the invention

In this study, vesicular stomatitis virus (VSV) lacking VSV G protein was used as a vector to construct chimeric virus strains co-expressing G protein and F protein of NiV Malaysian strain (NiV-Malaysia, NiVMY) and NiV-Bangladesh strain (NiVBD), respectively. The constructed strains are rVSV△G/NiVMYGF and rVSV△G/NiVBDGF; the virus can fully express the F and G proteins of Nipah virus on the surface of vesicular stomatitis virus (VSV) particles lacking VSV G protein, ensuring the integrity of the virus and making it replicable. At the same time, the virus has better biosafety and can be used for routine testing and preparation of its products.

On this basis, the present invention has been completed.

In the first aspect, the present invention provides a chimeric VSV recombinant virus strain that co-expresses NiV G and F proteins, wherein the chimeric VSV recombinant virus strains are rVSV△G/NiVMYGF and rVSV△G/NiVBDGF; vesicular stomatitis virus rVSV△G/NiVMYGF, deposit number: CCTCC NO: V2023110, deposit date: 2023.12.18, name of depository unit: China Center for Type Culture Collection; vesicular stomatitis virus rVSV△G/NiVBDGF, deposit number: CCTCC NO: V2023111, deposit date: 2023.12.18; name of depository unit: China Center for Type Culture Collection.

In a second aspect, the present invention provides a composition comprising chimeric VSV recombinant virus strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF.

Furthermore, the chimeric VSV recombinant virus strain may also be its nucleotide or its protein.

Furthermore, the protein also includes its fusions and derivatives.

Furthermore, the composition includes but is not limited to pharmaceutical compositions and immune preparations.

In a third aspect, the present invention provides a use of chimeric VSV recombinant virus strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF in the preparation of a preparation for preventing or treating diseases caused by Nipah virus infection.

Furthermore, the preparation may also be a vaccine and a vaccine composition thereof.

Furthermore, the vaccine composition also contains an adjuvant.

Furthermore, the adjuvant is selected from oil-in-water adjuvants, polymer and water adjuvants, water-in-oil adjuvants, aluminum hydroxide adjuvants, vitamin E adjuvants and combinations thereof.

Furthermore, the vaccine composition further comprises at least one additional antigen.

Furthermore, the administration route of the preparation is selected from: oral administration, sublingual administration, gastric or intestinal administration, topical administration, injection, intravenous injection, subcutaneous injection, intramuscular injection, transdermal administration, and/or inhalation administration.

Furthermore, the preparation can be: tablet capsule, powder, injection, syrup, solution, sustained release agent, rapid release agent, controlled release agent, emulsion, microemulsion, nano preparation, targeted preparation, suppository, ointment, gel, solid dispersion, inclusion compound and/or patch.

In a fourth aspect, the present invention provides an anti-Nipah virus antibody, wherein the antibody is prepared from chimeric VSV recombinant virus strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF.

Furthermore, the chimeric VSV recombinant viruses are rVSV△G/NiVMYGF and rVSV△G/NiVBDGF; vesicular stomatitis virus rVSV△G/NiVMYGF, deposit number: CCTCCNO: V2023110, deposit date: 2023.12.18, name of the depository: China Center for Type Culture Collection; vesicular stomatitis virus rVSV△G/NiVBDGF, deposit number: CCTCC NO: V2023111, deposit date: 2023.12.18; name of the depository: China Center for Type Culture Collection.

Furthermore, the antibody also includes its primers: the primers are as follows:

NiVMY-F-F:

GGACGAGCTGTACAAGTAAGCTAGCTATGAAAAAAACTAACAGATATCACGACGC GTACAACCATGGTAGTTATACTTGACAAGAGATG; (SEQ ID NO. 1)

NiVMY-F-R:

AGAGGCTGGAATTAGGAGACTGAGTAAACCGGGGATTGTTCAGAAGCTAGAAGTT AGGGGATTGTTCAGAAGCTAGAAGTTAGACAGCCTATGTCCCAATGTAGTAGAGATCC CC; (SEQ ID NO. 2)

NiVMY-G-F:

GTCTCCTAATTCCAGCCTCTCGAACAACTAATATCCTGTCTTTTCTATCCCTATGAA AAAAACTAACAGAGATCGATCTGTTTACGCGTACAACCATGCCGGCAGAAAACAAGA AAGTTAG; (SEQ ID NO. 3)

NiVMY-G-R:

GTCCAAACATGAAGAATCTGGCTAGCTTATGTACATTGCTCTGGTATCTTAACC; (SEQ ID NO. 4)

NiVBD-F-F:

TGGACGAGCTGTACAAGTAAGCTAGCTATGAAAAAAACTAACAGATATCACGACG CGTACAACCATGGCAGTTATACTTAACAAGAGATA; (SEQ ID NO.5)

NiVBD-F-R:

AGAGGCTGGAATTAGGAGACTGAGTAAACCGGGGATTGTTCAGAAGCTAGAAGTT AGGGGATTGTTCAGAAGCTAGAAGTTAGACTAGCCTATGTCCCAATGTAATAGAGATCC CC; (SEQ ID NO. 6)

NiVBD-G-F:

GTCTCCTAATTCCAGCCTCTCGAACAACTAATATCCTGTCTTTTCTATCCCTATGAA AAAAACTAACAGAGATCGATCTGTTTACGCGTACAACCATGCCGACAGAAAGCAAGA AAGTTAG; (SEQ ID NO. 7)

NIVBD-G-R:

GTCCAAACATGAAGAATCTGGCTAGCTTATGTACATTGCTCTGGTATCTTAAC; (SEQ ID NO. 8)

In a fifth aspect, the present invention provides a preparation for diagnosing a disease caused by Nipah virus infection; the preparation contains the anti-Nipah virus antibody as described in the fourth aspect.

Furthermore, the preparation may be a reagent or a kit for diagnostic testing.

In a sixth aspect, the present invention provides a chimeric VSV recombinant virus, a composition, and use of the composition in preparing anti-Nipah virus antibodies.

Furthermore, the antibodies include but are not limited to monoclonal antibodies, genetically engineered antibodies, multifunctional antibodies and antibodies prepared by phage technology.

Furthermore, the antibodies include but are not limited to diagnostic reagents and antibody therapeutic preparations.

Furthermore, the antibody also includes its primer: the primer is shown in SEQ ID NO.1-SEQ ID NO.8.

Beneficial Effects

1. This application uses VSV as a live virus vector, which has many advantages: such as ① the F protein and G protein of Nipah virus are efficiently and stably expressed on the surface of the viral envelope, which is helpful for studying pathogens with high biosafety requirements; ② the replication and assembly of the viral genome are completed in the cytoplasm, without the risk of host gene recombination, and as a vaccine vector, there is no risk of reverse transcription activity and integration into the host genome, and it is highly safe; ③ the genome is simple and easy to modify, and can express the G protein and F protein of Nipah virus at the same time; ④ the human body has low pre-existing immunity, and there is no pre-existing immunity problem against viral vectors, which has a certain self-limiting property; ⑤ inducing strong humoral and cellular immune responses; ⑥ VSV can obtain very high titer viruses when proliferating in most mammalian cells.

2. The chimeric VSV recombinant virus strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF constructed in the present application have good immunogenicity and biological activity; they can be detected under conventional experimental conditions, especially they can detect Nipah virus in samples without the need for special experimental conditions, they are highly safe and have no risk of infection.

3. The chimeric viruses rVSV△G/NiVMYGF and rVSV△G/NiVBDGF lacking VSV G protein constructed in this application have good immunogenicity and biological activity, and immunoelectron microscopy shows that they can be embedded in the surface of virus particles; inactivated chimeric viruses can induce high levels of neutralizing antibodies in mice immunized with them, and the dilution multiples of neutralizing antibody titers can reach 640 times and 512 times, respectively. Therefore, the two strains of viruses have high growth titers, good immunogenicity, good safety, can improve the efficiency of large-scale production, are conducive to safe production management, and are ideal strains for NiV inactivated vaccines.

4. The chimeric viruses rVSV△G/NiVMYGF and rVSV△G/NiVBDGF lacking VSV G protein constructed in this application can serve as an important viral resource for the effective prevention and control, diagnostic testing, vaccine preparation and antiviral treatment products of Nipah disease in the future based on their complete viral structure, higher immunogenicity and better safety.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 Immunofluorescence results of rVSV△G/NiVMYGF and rVSV△G/NiVBDGF.

Figure 2 Transmission electron microscopy and immunoelectron microscopy results of rVSV△G/NiVMYGF and rVSV△G/NiVBDGF.

Fig. 3 Virus growth curve.

Figure 4 Virus safety evaluation

Figure 5 The results of neutralizing antibody detection using rVSV△G/NiVMYGF and rVSV△G/GFP/NiVMYGF and rVSV△G/GFP/NiVBDGF respectively.

Figure 6 The results of neutralizing antibody detection using rVSV△G/NiVBDGF and rVSV△G/GFP/NiVBDGF respectively.

Detailed ways

The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the embodiments described below can be combined with each other as long as they do not conflict with each other.

The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

Vesicular stomatitis virus (VSV) is a representative model virus of the Rhabdoviridae family. It has a simple structure, strong replication ability, and can quickly induce disease. It is widely used as a research model for the invasion, replication, and assembly mechanisms of RNA enveloped viruses. VSV can efficiently insert foreign genes and stably express foreign target proteins, and can be used as a viral vector in the study of other virus families. Vesicular stomatitis virus belongs to the Rhabdoviridae family, a non-segmented single-negative-strand RNA virus, including the New Jersey type and the Indiana type. The virus is bullet-shaped or cylindrical, with an envelope, and the genome is about 11Kb long, encoding five structural proteins: nucleoprotein N, phosphoprotein P, matrix protein M, glycoprotein G and RNA polymerase protein L; wherein the G protein mediates the binding of the virus to the host cell and activates the immune response. In the present application, the G protein and F protein co-expressing Nipah disease chimeric virus strain of the present application are constructed by deleting its own glycoprotein G; the constructed strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF have good immunogenicity and biological activity; it can be clearly detected that the F and G proteins of the Nipah virus are fully expressed on the surface of the particles of VSV lacking G protein, which ensures the integrity of the cystovirus and realizes the replicability of the virus; wherein the vesicular stomatitis virus rVSV△G/NiVMYGF, the deposit number is: CCTCC NO:V2023110, preservation date: 2023.12.18, name of the preservation unit: China Center for Type Culture Collection; Vesicular Stomatitis Virus rVSV△G/NiVBDGF, preservation number: CCTCCNO:V2023111, preservation date: 2023.12.18; name of the preservation unit: China Center for Type Culture Collection.

Example 1

1.1 Synthesis of chimeric VSV virus expressing NiV G and F proteins

The G and F proteins of NiV-Malaysia (NiVMY) and Bangladesh (NiV-Bangladesh, NiVBD) were artificially synthesized. Primers were designed to introduce the start, stop and Kozak sequences of VSV gene before the start codon ATG of the upstream primer.

Table 1 Primers for constructing recombinant VSV full-length cDNA expressing NiV F protein or G protein

The target fragment was amplified by PCR, and the PCR product was recovered by 1% agarose gel electrophoresis, and the concentration of the recovered product was measured and stored at -20°C. The PCR product was homologously recombined with the enzyme digestion recovery product (Nhe I) of the vector pCI-Rz-VSVΔG-eGFP-FL to obtain the recombinant plasmids pCI-RzVSV△G-NiVMYGF and pCI-RzVSV△G-NiVBDGF expressing NiVMY G and F proteins and NiVBD G and F proteins. The above two recombinant plasmids were co-transfected into BHK-21 cells with the auxiliary plasmids pBS-VSV-N, pBS-VSV-P, and pBS-VSV-L expressing the N gene, P gene, and L gene of VSV by calcium phosphate transfection method. The transfection system is as follows:

Table 2 Transfection system

Mix the reaction components in tube A and add them to tube B. After mixing, let it stand for 20 minutes and then add it dropwise to the culture medium of BHK-21 cells and place it in an incubator at 37°C and 5% _CO2 .

72 hours after transfection, the cell supernatant was harvested and serially passaged in Vero-E6 cells until obvious cytopathic effect (CPE) was formed. The chimeric viruses were collected and named rVSV△G/NiVMYGF and rVSV△G/NiVBDGF, respectively.

1.2 Identification of recombinant chimeric VSV

Vero-E6 cells were infected with chimeric viruses rVSV△G/NiVMYGF and rVSV△G/NiVBDGF and wild-type VSV at MOI = 0.01, and the cells were collected 36 hours after infection. After cell lysis, immunofluorescence identification was performed using mouse anti-NiV-G and NiV-F serum (1:100) as primary antibody.

The analysis results showed that the chimeric viruses rVSV△G/NiVMYGF and rVSV△G/NiVBDGF could correctly express NiVF and G proteins (as shown in Figure 1).

1.3 Observation of chimeric virus morphology

The supernatant of virus-infected cells was collected, cell debris was removed, and samples were prepared by phosphotungstic acid negative staining method, and the virus morphology was observed under an electron microscope. To observe the chimeric virus envelope fibers, the virus samples were labeled with G and F protein specific antibodies respectively.

Electron microscopy showed that the two chimeric viruses were in the shape of bullets, and the virus particles and glycoproteins on their surface could be observed. Immunoelectron microscopy negative staining results showed that the surface of the virus particles could be attached by specific gold particles (as shown in Figure 2).

1.4 Chimeric virus growth kinetics

The two chimeric viruses were inoculated into Vero-E6 cells at MOI=0.01, and the cell supernatants were collected at 12h, 24h, 36h, 48h, 60h, and 72h after infection, and _TCID50 was determined.

Construct vsv chimeric viruses rVSV△G/NiVMYG and rVSV△G/NiVMYF that only express NiVMY G protein or NiVMY F protein; construct vsv chimeric viruses rVSV△G/NiVBDG and rVSV△G/NiVBDF that only express NiVBD G protein or NiVBD F protein. Mix rVSV△G/NiVMYG and rVSV△G/NiVMYF in equal proportions, and mix rVSV△G/NiVBDG and rVSV△G/NiVBDF in equal proportions, inoculate Vero-E6 cells at MOI=0.01, collect cell supernatants at 12h, 24h, 36h, 48h, 60h, and 72h after infection, and determine _TCID50 .

As shown in Figure 3, the growth trends of the two chimeric viruses were basically consistent with those of wild-type VSV, reaching a peak at 36-48 hours. The titers of rVSV△G/NiVMYGF and rVSV△G/NiVBDGF were 10 ^8.28 TCID ₅₀ /mL and 10 ^8.58 TCID ₅₀ /mL, respectively. These were higher than the virus titers after mixed infection with rVSV△G/NiVMYG+rVSV△G/NiVMYF and rVSV△G/NiVBDG+rVSV△G/NiVBDF.

Example 2 Chimeric virus mouse safety test

Chimeric virus rVSV△G/NiVMYGF and rVSV△G/NiVBDGF virus solution 5×10 ⁵ TCID ₅₀ /0.1ml were injected intramuscularly into 10 6-week-old female BALB/c mice, and 10 mice were inoculated with the same volume of PBS as control. The health status of mice was observed daily and the weight changes were recorded for two consecutive weeks.

As shown in Figure 4, all mice inoculated with the chimeric virus survived without any clinical symptoms. The weight growth curve of mice in the experimental group was consistent with that in the PBS group, indicating that the chimeric virus was not pathogenic to mice.

Example 3 Chimeric virus mouse immunization test

Chimeric viruses rVSV△G/NiVMYGF and rVSV△G/NiVBDGF were inactivated and injected intramuscularly into 6 6-week-old female BALB/c mice, and then boosted once 3 weeks later with an immunization dose of 1×10 ⁶ TCID ₅₀ /0.1ml. Blood was collected at 2, 3, 4, 5, and 6 weeks after the first immunization to prepare serum.

The neutralization test was performed using chimeric viruses rVSV△G/GFP/NiVMYGF and rVSV△G/GFP/NiVMYGF to detect the level of neutralizing antibodies against NiV G and F in serum. The serum to be tested was diluted 2-fold using the fixed virus dilution serum method and mixed with 1×10 ³ TCID ₅₀ of chimeric virus rVSV△G/GFP/NiVGF, with 5 parallel controls for each dilution. After the serum and virus mixture was exposed to 37℃ for 1h, it was inoculated into Vero-E6 cells in a 96-well plate and observed under an inverted fluorescence microscope 24h after infection. The highest dilution that could inhibit 50% of the fluorescence was taken as its neutralization titer.

The results are shown in Figure 5. The mouse serum 2 weeks after the first immunization with rVSV△G/NiVMYGF can effectively block the infection of rVSV△G/GFP/NiVMYGF and rVSV△G/GFP/NiVBDGF. After booster immunization, the neutralizing antibody titer was further increased, reaching the highest 5 weeks after the first immunization, with dilution multiples reaching 640 times and 512 times, respectively.

As shown in Figure 6: Mouse serum 2 weeks after the first immunization with rVSV△G/NiVBDGF can effectively block rVSV△G/GFP/NiVMYGF and rVSV△G/GFP/NiVBDGF infection. After booster immunization, the neutralizing antibody titer was further increased, reaching the highest 5 weeks after the first immunization, and the dilution multiple could reach 512 times.

Claims (10)

1. A chimeric VSV recombinant virus strain that co-expresses NiV G and F proteins, wherein the chimeric VSV recombinant virus strains are rVSV△G/NiVMYGF and rVSV△G/NiVBDGF; wherein the vesicular stomatitis virus rVSV△G/NiVMYGF, the deposit number: CCTCC NO: V2023110, the deposit date: 2023.12.18, the name of the depository: China Center for Type Culture Collection; the vesicular stomatitis virus rVSV△G/NiVBDGF, the deposit number: CCTCC NO: V2023111, the deposit date: 2023.12.18, the name of the depository: China Center for Type Culture Collection. 2. A composition comprising chimeric VSV recombinant virus strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF. 3. A composition as described in claim 2, characterized in that the chimeric VSV recombinant virus strain can also be its nucleotide or its protein. 4. Use of chimeric VSV recombinant virus strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF in the preparation of preparations for preventing or treating diseases caused by Nipah virus infection. 5. The use according to claim 4, characterized in that the preparation can also be a vaccine and a vaccine composition thereof. 6. An antibody against Nipah virus, the antibody being prepared from chimeric VSV recombinant virus strains rVSV△G/NiVMYGF and rVSV△G/NiVBDGF, wherein the chimeric VSV recombinant viruses are rVSV△G/NiVMYGF and rVSV△G/NiVBDGF; wherein the vesicular stomatitis virus rVSV△G/NiVMYGF, the deposit number: CCTCC NO: V2023110, the deposit date: 2023.12.18, the name of the depository: China Center for Type Culture Collection; the vesicular stomatitis virus rVSV△G/NiVBDGF, the deposit number: CCTCC NO: V2023111, the deposit date: 2023.12.18, the name of the depository: China Center for Type Culture Collection. 7. The antibody according to claim 5, characterized in that the antibody further comprises a primer thereof: the primer SEQ ID NO.1-SEQ ID NO.8. 8. A preparation for diagnosing a disease caused by Nipah virus infection; the preparation contains the anti-Nipah virus antibody according to claim 5. 9. A chimeric VSV recombinant virus, a composition and use of the composition in preparing antibodies against Nipah virus. 10. The use according to claim 9, characterized in that the antibodies include but are not limited to monoclonal antibodies, genetically engineered antibodies, multifunctional antibodies and antibodies prepared by phage technology.