Recombinant herpesvirus turkey for co-expressing Newcastle disease virus F gene and infectious bursal disease virus VP2 gene and application of recombinant herpesvirus turkey

Abstract

The invention provides a recombinant herpesvirus turkey for co-expressing a Newcastle disease virus F gene and an infectious bursal disease virus VP2 gene as well as a construction method and application of the recombinant herpesvirus turkey. The recombinant clone technology is utilized, an expression framework containing a Newcastle disease virus gene VII type strain F gene and an infectious bursal disease virus super virulent strain VP2 gene is inserted between 95322-95323 nucleotides of a turkey herpesvirus FC126 strain, and the recombinant clone with the F gene and the VP2 gene expression framework inserted into a turkey herpesvirus genome is constructed and obtained. And the recombinant herpesvirus turkey vaccine strain H20101 for co-expressing the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene is rescued and obtained by the recombinant herpesvirus turkey vaccine strain H20101. The vaccine prepared from the recombinant turkey herpesvirus provided by the invention can provide dual protection against super virulent Newcastle disease virus and infectious bursal disease virus, overcomes the defect that the existing vaccine is difficult to prevent two diseases by one injection, and has a good market application prospect.

Description

Technical Field

[0001] The invention belongs to the field of genetic engineering vaccines, and specifically relates to a recombinant turkey herpes virus that co-expresses a Newcastle disease virus F gene and an infectious bursal disease virus VP2 gene and an application thereof. Background Art

[0002] Herpesvirus of turkeys (HVT) is a herpesvirus that is non-pathogenic to chickens. It has a large genome and many replication-non-essential genes that can be inserted or replaced by exogenous genes. It is an ideal viral vector for constructing recombinant live vector vaccines. Compared with other viral vectors, HVT has many advantages as a viral vector. It is non-pathogenic to chickens and other animals and is safe to use; the immune effect of HVT vaccine is not interfered by maternal antibodies and is suitable for early immunization of one-day-old chicks in hatcheries; after vaccination, HVT exists in the chicken body for a long time, stimulating the body to produce high antibody levels and maintain them for life, and lifelong immunity can be obtained with one vaccination; HVT vaccine not only has low production costs, but can also be freeze-dried, making it easy to store and transport.

[0003] Researchers at home and abroad have developed a series of recombinant virus vector vaccine strains based on turkey herpes virus HVT vector, such as Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), H9 subtype avian influenza virus (AIV), infectious laryngotracheitis virus (ILTV), etc. These vector vaccines effectively overcome the defects of inactivated vaccines and attenuated live vaccines that the immune effects are easily interfered by maternal antibodies, and effectively solve the current situation that the virus is easy to infect early chicks. When recombinant turkey herpes viruses expressing different exogenous genes are inoculated into one-day-old chickens at the same time, there will be a problem of two or more recombinant virus vector vaccines competing with each other in the chicken, resulting in immune failure. Moreover, when different types of exogenous genes are inserted into the same turkey herpes virus vector at the same time, there will be a problem of only having a good immune effect on one of the diseases, or the immune effect on all diseases is not ideal. Therefore, there is an urgent need for a recombinant HVT vector vaccine that can simultaneously express multiple exogenous antigen genes and stably propagate, and provide good immune protection effects. Summary of the invention

[0004] The object of the present invention is to provide a recombinant turkey herpes virus which co-expresses the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene.

[0005] The present invention also aims to provide a method for constructing a recombinant turkey herpes virus that co-expresses the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene.

[0006] The present invention also aims to provide an application of a recombinant turkey herpes virus that co-expresses the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] A recombinant turkey herpesvirus that co-expresses the Newcastle disease virus F gene and the infectious bursal virus VP2 gene. The recombinant turkey herpesvirus is obtained by inserting an expression framework CAGW-F2AV2 comprising a chicken β-actin promoter, the coding sequence F2AV2 of the Newcastle disease virus F gene and the infectious bursal virus VP2 gene, a woodchuck hepatitis virus post-transcriptional regulatory sequence, and a rabbit β-globulin polyadenylation sequence into the turkey herpesvirus genome.

[0009] Furthermore, the coding sequence F2AV2 is obtained by connecting the Newcastle disease virus F gene coding sequence and the infectious bursal virus VP2 gene coding sequence with the porcine teschovirus 2A self-cleaving peptide coding sequence, and the nucleotide sequence of the coding sequence F2AV2 is shown in SEQ ID NO.1.

[0010] Furthermore, the expression frame CAGW-F2AV2 is obtained by cloning F2AV2 into the chicken β-actin promoter and the rabbit β-globulin polyadenylic acid sequence of the pCAGGS vector, and inserting the woodchuck hepatitis virus post-transcriptional regulatory sequence between the F2AV2 sequence and the rabbit β-globulin polyadenylic acid sequence. The nucleotide sequence of the expression frame CAGW-F2AV2 is shown in SEQ ID NO.2.

[0011] Furthermore, the recombinant turkey herpes virus is obtained by co-transfecting CEF cells with recombinant cosmids HVT01, HVT02, HVT03, HVT05, HVT06 containing HVT genomic DNA fragments and recombinant cosmids HVT04-53-F2AV2 containing CAGW-F2AV2 expression framework, and then rescuing the virus; the recombinant cosmids HVT01, HVT02, HVT03, HVT05, HVT06 contain turkey herpes virus FC126, respectively. The nucleotide fragments of the strain genome are positions 1-30189, 21572-61476, 50871-90478, 96776-135815, and 129602-159160; the recombinant cosmid HVT04-53-F2AV2 is obtained by inserting the expression framework CAGW-F2AV2 on the basis of HVT04; the recombinant cosmid HVT04 contains the nucleotide fragment of positions 73762-108139 of the FC126 strain genome.

[0012] Furthermore, the recombinant turkey herpes virus is obtained by inserting the expression frame CAGW-F2AV2 into the 95322-95323 nucleotides of the turkey herpes virus FC126 strain genome.

[0013] The invention discloses a recombinant turkey herpes virus which co-expresses the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene in the preparation of Newcastle disease and infectious bursal disease vaccines.

[0014] The invention utilizes the recombinant cloning technology to insert the expression frame containing the Newcastle disease virus gene type VII strain F gene and the infectious bursal disease virus super virulent strain VP2 gene into the 95322-95323 nucleotides of the turkey herpes virus FC126 strain genome, and constructs the recombinant turkey herpes virus vaccine strain H20101 which co-expresses the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene. After the recombinant virus vaccine strain is used to immunize specific pathogen-free (SPF) chickens, the SPF chickens can obtain immune protection against the Newcastle disease virus gene type VII virulent strain and the infectious bursal disease super virulent strain, and can be used for the preparation of Newcastle disease and chicken infectious bursal disease vaccines.

[0015] The vaccine prepared from the recombinant turkey herpes virus provided by the present invention can simultaneously provide multiple protections against Newcastle disease virus and infectious bursal disease virus virulent infections, and has good market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which constitute part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention. In the accompanying drawings:

[0017] Figure 1 The figure shows the PCR identification result of the recombinant cosmid HVT04-53-F2AV2 expressing the F gene and the VP2 gene, where M is the DL5000 Marker, 1 is HVT04-53-F2AV2, and 2 is HVT04;

[0018] Figure 2 This is a picture of plaque lesions produced by the recombinant virus H20101 on CEF;

[0019] Figure 3 The figure shows the PCR identification result of the recombinant virus H20101 genomic DNA, where M is DL5000 Marker, 1 is H20101, and 2 is FC126;

[0020] Figure 4 The indirect immunofluorescence assay was used to detect the expression of F and VP2 proteins in CEF infected with the recombinant virus H20101;

[0021] Figure 5 This is a graph showing the replication kinetics of the recombinant virus H20101 on CEF cells;

[0022] Figure 6The figure is the result of PCR test of genetic stability of recombinant virus H20101, where M is DL5000 Marker, 1 is H20101-F5, 2 is H20101-F10, 3 is H20101-F15, 4 is H20101-F20, and 5 is FC126;

[0023] Figure 7 This is the result of indirect immunofluorescence test of the 20th generation recombinant virus expressing F and VP2 proteins;

[0024] Figure 8 This is the survival curve of chickens inoculated with the recombinant virus H20101 after being challenged with the strong NDV virus;

[0025] Fig. 9 This is the survival curve of chickens inoculated with the recombinant virus H20101 after being challenged with super-virulent IBDV. DETAILED DESCRIPTION

[0026] The following specific descriptions are exemplary and are intended to provide further explanation of the present invention. It should be understood by those skilled in the art that the details and forms of the technical solution of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements fall within the protection scope of the present invention.

[0027] Unless otherwise specified, the test methods used in the following experimental examples are conventional methods.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0029] Example 1: Construction and identification of recombinant HVT expressing NDV F and IBDV VP2 genes

[0030] 1.1 Establishment of the reverse genetics system of HVT FC126 strain

[0031] The genomic DNA of HVT FC126 strain (GenBank accession number AF291866) was extracted and cloned into the pCC1Fos vector in segments according to the instructions of the CopyControlFosmidLibraryProductionKit. The constructed recombinant cosmids were terminally sequenced using primers pCC1F and pCC1R (see Table 1 for details). According to the sequencing results, six recombinant cosmids HVT01, HVT02, HVT03, HVT04, HVT05, and HVT06 that cloned the genomic DNA fragments of FC126 strain and could be spliced ​​to cover the complete HVT genome were selected. Among them, HVT01 contains the nucleotide fragment of 1-30189 position of FC126 genome, HVT02 contains the nucleotide fragment of 21572-61476 position of FC126 genome, HVT03 contains the nucleotide fragment of 50871-90478 position of FC126 genome, HVT04 contains the nucleotide fragment of 73762-108139 position of FC126 genome, HVT05 contains the nucleotide fragment of 96776-135815 position of FC126 genome, and HVT06 contains the nucleotide fragment of 129602-159160 position of FC126 genome. The above-mentioned 6 recombinant clays cloned with FC126 genomic DNA fragments were extracted, and the 6 recombinant clays were co-transfected into chicken embryo fibroblasts (CEF) by calcium phosphate transfection method. The appearance of cytopathic effect can be observed after 4-5 days of transfection, that is, the parental virus strain FC126 was rescued.

[0032] 1.2 Construction and identification of recombinant cosmids expressing NDV F and IBDV VP2 genes

[0033] According to the F gene coding region sequence of NDV genotype VII strain GM strain (GenBank accession number DQ486859), the target gene NDF was synthesized by chicken codon optimization design, and the porcine Teschen virus 2A (P2A) self-cleavage peptide sequence was added to its C-terminus. According to the VP2 gene sequence of IBDV super strain (vvIBDV) UPM766 strain (GenBank accession number MT505341), the target gene IBDV2 was synthesized after chicken codon optimization design. The target gene F2AV2 (SEQ ID NO.1) containing the F gene and VP2 gene coding sequences was obtained by fusion PCR amplification using primers NDFP1F, NDV2P1R, NDA2P2F and A2P2R, wherein the F gene and VP2 gene coding regions are connected by the self-cleavage peptide P2A coding sequence. The purified PCR product was cloned into the downstream of the chicken β-actin promoter of the pCAGGS vector through the EcoRI and ClaI restriction sites; at the same time, in order to enhance the transcription and translation efficiency of the target gene, the woodchuck hepatitis virus post-transcriptional regulatory sequence was inserted between the target gene F2AV2 and the rabbit β-globulin polyadenylation sequence to obtain the recombinant plasmid pCAGW-F2AV2 that co-expresses the NDV F gene and the IBDV VP2 gene. The recombinant plasmid was sequenced using primers CAGF and CAGR, and it was found that the cloned target gene expression cassette sequence was correct.

[0034] According to the instructions of the Counter Selection BAC Modification Kit, the F2AV2 gene expression framework CAGW-F2AV2 (SEQ ID NO.2) was inserted into the 95322-95323 nucleotides of the FC126 genome in the recombinant cosmid HVT04 using the Red / ET recombination method to construct the recombinant cosmid HVT04-53-F2AV2 that co-expresses the NDV F gene and the vvIBDV VP2 gene. The target gene primer vvIBDVP2F and the target gene downstream homology arm primer HVT54R were used to identify whether the recombinant cosmid HVT04-53-F2AV2 was inserted into the target gene expression framework by PCR, and the PCR product was sequenced and identified. The results showed that a PCR fragment of about 2800 bp was obtained ( Figure 1 ), the size was consistent with expectations. The sequencing results showed that the PCR product contained the VP2 gene sequence and the downstream homology arm sequence of the target gene expression cassette, and the sequence was correct. However, the negative control sample (parental cosmid HVT04) had no target gene insertion sequence, and the PCR result was negative. The above results indicate that the recombinant cosmid HVT04-53-F2AV2 was constructed correctly.

[0035] Table 1 PCR primers used to construct and identify recombinant cosmids of F gene and VP2 gene

[0036] Primer name Primer nucleotide sequence number pCC1F SEQ ID NO.3 pCC1R SEQ ID NO.4 NDFP1F SEQ ID NO.5 NDV2P1R SEQ ID NO.6 NDV2P2F SEQ ID NO.7 V2P2R SEQ ID NO.8 vVvV SEQ ID NO.9 HVT54R SEQ ID NO.10 CAGF SEQ ID NO.11 CAGR SEQ ID NO.12

[0037] 1.3 Rescue and identification of recombinant HVT expressing NDV F and IBDV VP2 genes

[0038] The recombinant cosmid HVT04-53-F2AV2 and other parental cosmids cloned with HVTFC126 strain genome fragments were extracted using a plasmid extraction kit. The recombinant cosmid HVT04-53-F2AV2 and parental cosmids HVT01, HVT02, HVT03, HVT05, and HVT06 were co-transfected into CEF cells using the calcium phosphate transfection method. The virus was harvested after plaque lesions appeared after 4-5 days of culture, and was continuously passaged and preserved in CEF cells. The recombinant virus with the F2AV2 expression frame inserted between nucleotides 95322-95323 of the HVT genome was rescued and named H20101. The plaque lesions produced by the recombinant virus on CEF were as follows: Figure 2 shown.

[0039] The recombinant virus genomic DNA was extracted, and the parent virus FC126 strain genomic DNA was used as a control. The recombinant virus was identified by PCR using the target gene specific primer vvIBDVP2F and the target gene downstream homology arm primer HVT54R, and the PCR product was further sequenced and analyzed. The PCR results showed that the PCR product obtained by recombinant virus amplification was about 2800 bp in length, which was consistent with the expected size. Figure 3 As shown. The sequencing results showed that the PCR product contained the VP2 gene sequence and the downstream homology arm sequence of the target gene expression cassette, and the sequence was correct. However, the parent virus FC126 had no target gene inserted, and the PCR result was negative. The above results showed that the target gene F2AV2 was correctly inserted into the genome of the HVT FC126 strain, and the recombinant virus H20101 was correctly constructed.

[0040] Example 2: In vitro biological characteristics analysis of recombinant HVT expressing NDV F and IBDV VP2 genes

[0041] 2.1 Detection of F protein and VP2 protein expressed by recombinant virus H20101

[0042] The recombinant virus H20101 and the parent virus FC126 were inoculated into CEF cells, and after plaque lesions appeared after 3-4 days of culture, the cells were fixed with anhydrous ethanol, and the expression of F protein and VP2 protein was detected by indirect immunofluorescence test using NDV positive serum and VP2 protein monoclonal antibody as primary antibodies, FITC-labeled rabbit anti-chicken IgG and FITC-labeled goat anti-mouse IgG as secondary antibodies, respectively. CEF infected with the parent virus FC126 was used as a negative control. The results showed that the cells infected with the recombinant virus H20101 were able to react with NDV positive serum and VP2 protein monoclonal antibody, showing green fluorescence signals ( Figure 4 ). No fluorescence was observed in cells infected with the parental virus FC126 strain and in control cells that were not infected. The above results indicate that the recombinant virus H20101 can co-express F protein and VP2 protein in infected cells.

[0043] 2.2 Analysis of in vitro replication characteristics of recombinant virus H20101

[0044] The recombinant virus H20101 and the parental virus FC126 were inoculated on CEF in a 6-well plate at a dose of 100 plaque-forming units (PFU). After infection, the virus-containing cells were collected every 24 hours until 144 hours after infection. The viruses collected at each time point were inoculated into CEF, the number of plaques in the virus solution at each time point was determined, and the in vitro replication kinetic curve of the virus was drawn to analyze the in vitro replication characteristics of the recombinant virus H20101 and the parental virus in CEF. The results showed that the replication titers of the recombinant virus H20101 and the parental virus FC126 reached the highest peak at 120 hours after infection, which were 1.82×10 5 PFU / ml and 2.01×10 5 PFU / ml, the titer of the recombinant virus at each time point after infection of CEF was not significantly different from that of the parental virus (P>0.05)( Figure 5 ). The above results show that the replication characteristics of the recombinant virus H20101 in CEF are consistent with those of the parent virus FC126 strain.

[0045] 2.3 Genetic stability test of recombinant virus H20101

[0046] The 5th generation recombinant virus H20101 was continuously passaged on CEF to the 20th generation. The 5th, 10th, 15th and 20th generation cytotoxic cells were selected, and the viral genomic DNA was extracted for PCR identification and sequencing to detect the genetic stability of the target gene sequence in the recombinant viral genome. At the same time, the above-mentioned 20th generation recombinant virus was inoculated into CEF cells, and an indirect immunofluorescence test was performed with NDV positive serum and VP2 monoclonal antibody to detect the expression stability of the target genes F and VP2. The PCR identification results showed that the target genes F and VP2 were stably present in the HVT genome, and the 5th, 10th, 15th and 20th generation recombinant viruses could be amplified to obtain a target gene band of about 2800bp in size ( Figure 6 ), which was consistent with expectations. The sequencing results showed that the target gene sequence did not undergo any mutation during the passage process and the sequence was correct. The above-mentioned 20th generation recombinant virus was taken for indirect immunofluorescence test to detect the expression of the target genes F and VP2 during the passage process. The results showed that after the recombinant virus H20101 was continuously passed on CEF cells to the 20th generation, the target genes F and VP2 could still be stably expressed ( Figure 7 ). The above results show that the recombinant virus H20101 has good genetic stability.

[0047] Example 3: Safety and immunogenicity testing of recombinant virus H20101

[0048] 3.1 Safety testing of recombinant virus H20101

[0049] The fifth generation recombinant virus H20101 was inoculated into one-day-old SPF chickens at a dose of 4000 PFU / chicken, and the clinical symptoms of each group of chickens were observed every day after inoculation. 28 days after inoculation, 5 test chickens were randomly selected from each group, and their weights were weighed to evaluate the effect of the recombinant virus H20101 on the growth and development of the test chickens; the 5 chickens selected from each group were killed, and the bursa of Fabricius, thymus, spleen, liver and other organs were collected, weighed, and observed for atrophy or swelling symptoms. The results showed that the recombinant virus H20101 did not cause adverse clinical reactions in the test chickens after inoculation of SPF chickens, and the feeding and drinking of the immunized chickens were normal. 28 days after inoculation, the weighing and autopsy results showed that the weight of the chickens in the recombinant virus H20101 inoculation group was not significantly different from that of the normal uninoculated control group; the test chickens were autopsied, and the bursa of Fabricius, thymus, spleen, liver and other organs were collected. The results showed that the above organs were normal and no obvious clinical lesions were found. The above results show that the recombinant virus H20101 is safe for SPF chickens.

[0050] 3.2 Immunogenicity test of recombinant virus H20101

[0051] 60 one-day-old SPF chicks were randomly divided into 3 groups, 20 in each group; Group 1 was subcutaneously inoculated with the recombinant virus H20101 at a dose of 4000 PFU / chicken, Group 2 was inoculated with the parent virus FC126 at the same dose, and Group 3 was not immunized as a blank control group. 28 days after immunization, 10 chickens in Group 1 and Group 2 were respectively challenged with the virulent NDV of gene type VII, and observed for 14 days after the challenge, the clinical symptoms of the test chickens were recorded, and the survival of the chickens in each group was counted. The remaining 10 chickens in Group 1 and Group 2 were respectively challenged with the super-strong IBDV, and observed for 7 days after the challenge, the clinical symptoms of the test chickens were recorded, and the survival was counted; 7 days after the challenge, the test chickens were dissected and the lesions of the bursal follicle were observed. Group 3 was not challenged and served as a healthy control group.

[0052] The results showed that all 10 chickens vaccinated with the recombinant virus H20101 survived the NDV challenge during the observation period; all 10 chickens in the parental virus FC126 immunization group died after NDV challenge ( Figure 8 ). All 10 chickens vaccinated with the recombinant virus H20101 survived the observation period after being challenged with IBDV super-virulent virus, and there was no obvious lesion in the bursa of Fabricius; 8 of the 10 chickens vaccinated with the parental virus FC126 died after being challenged with IBDV super-virulent virus ( Fig. 9 ), the bursa of Fabricius showed atrophy, strip-like hemorrhage or yellow jelly-like infiltration lesions. The above results show that the recombinant virus H20101 has a good immune protection effect against NDV strong virus and IBDV super strong virus attack.

Claims

1. A recombinant turkey herpes virus that co-expresses the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene, characterized in that: The recombinant turkey herpes virus is obtained by inserting the expression frame CAGW-F2AV2 containing chicken beta-actin promoter, Newcastle disease virus F gene and infectious bursal disease virus VP2 gene coding sequence F2AV2, woodchuck hepatitis virus post-transcriptional regulatory sequence and rabbit beta-globulin polyadenylic acid sequence into the turkey herpes virus genome.

2. The recombinant turkey herpes virus co-expressing the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene according to claim 1, characterized in that: The coding sequence F2AV2 is obtained by connecting the Newcastle disease virus F gene coding sequence and the infectious bursal disease virus VP2 gene coding sequence with the porcine teschovirus 2A self-cleaving peptide coding sequence. The nucleotide sequence of the coding sequence F2AV2 is shown in SEQ ID NO.

1.

3. The recombinant turkey herpes virus co-expressing the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene according to claim 1, characterized in that: The expression frame CAGW-F2AV2 is obtained by cloning F2AV2 into the chicken β-actin promoter and the rabbit β-globulin polyadenylic acid sequence of the pCAGGS vector, and inserting the woodchuck hepatitis virus post-transcriptional regulatory sequence between the F2AV2 sequence and the rabbit β-globulin polyadenylic acid sequence. The nucleotide sequence of the expression frame CAGW-F2AV2 is shown in SEQ ID NO.

2.

4. The recombinant turkey herpes virus co-expressing the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene according to claim 1, characterized in that: The recombinant turkey herpes virus is obtained by co-transfecting chicken embryo fibroblasts with recombinant cosmids HVT01, HVT02, HVT03, HVT05, HVT06 containing genomic DNA fragments of turkey herpes virus FC126 strain and recombinant cosmid HVT04-53-F2AV2 containing CAGW-F2AV2 expression frame, and then rescuing the virus; the recombinant cosmids HVT01, HVT02, HVT03, HVT05, HVT06 respectively contain genomic DNA fragments of turkey herpes virus FC126 strain Nucleotide fragments at positions 1-30189, 21572-61476, 50871-90478, 96776-135815, and 129602-159160; the recombinant cosmid HVT04-53-F2AV2 is obtained by inserting the expression framework CAGW-F2AV2 described in claim 1 on the basis of HVT04; the recombinant cosmid HVT04 contains the nucleotide fragment at positions 73762-108139 of the genome of turkey herpesvirus FC126 strain.

5. The recombinant turkey herpes virus co-expressing the Newcastle disease virus F gene and the infectious bursal disease virus VP2 gene according to claim 1, characterized in that: The expression framework CAGW-F2AV2 according to claim 1 is inserted into the 95322-95323 nucleotides of the genome of the turkey herpesvirus FC126 strain.

6. Use of the recombinant turkey herpes virus co-expressing Newcastle disease virus F gene and infectious bursal disease virus VP2 gene as claimed in claim 1 in the preparation of Newcastle disease and infectious bursal disease vaccines.

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