Enhanced immune response and protection efficacy of a DNA vaccine constructed by linkage of the Mycobacterium tuberculosis Ag85B-encoding gene with the BVP22-encoding gene.
Plasmid DNA vaccines have been widely explored for use in tuberculosis immunization but their immunogenicity needs improvement. In the present study, we incorporated the bovine herpesvirus 1 VP22 (BVP22)-encoding gene, which encodes a protein that demonstrates a capability for disseminating the expressed antigen to neighbouring cells, into a DNA vector in which it was fused to the Ag85B-encoding gene of Mycobacterium tuberculosis (Mtb), and investigated whether this linkage could enhance immune response and protective efficacy in C57BL/6 mice compared to plasmid DNA encoding Ag85B alone. After immunization in mice, Ag85B-specific ELISA antibodies and spleen lymphocyte proliferative responses induced by DNA co-expressing BVP22 and Ag85B were significantly higher than those obtained in mice immunized with Ag85B-encoding DNA alone, except for the number of gamma interferon secreting cells. In addition, based on histopathological examination and bacterial-load determination in lung and spleen, protection against intravenous Mtb H37Rv challenge evoked by the BVP22-Ag85B DNA immunization exceeded the response elicited by Ag85B DNA alone, which was not significantly different from that provided by Bacillus Calmette-Guérin (BCG). These results suggested that DNA vaccine consisting of BVP22 and Ag85B-encoding DNA enhanced immune response and protection against intravenous Mtb H37Rv challenge in mice, indicating that BVP22-encoding DNA might be a promising tool to enhance TB DNA vaccine efficacy.
Yao
Wanhong
W
Department of Microbiology and Parasitology, School of Medicine, Wuhan University, Wuhan, PR China.
Liu
Shengwu
S
Department of Immunology, School of Medicine, Wuhan University, Wuhan, PR China.
Qu
Xueju
X
Department of Immunology, School of Medicine, Wuhan University, Wuhan, PR China.
Xiao
Shaobo
S
National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430071, Hubei, PR China.|Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430071, Hubei, PR China.
Liu
Yan
Y
Department of Immunology, School of Medicine, Wuhan University, Wuhan, PR China.
Liu
Junyan
J
Animal Center of Wuhan University, Wuhan University, Wuhan, PR China.|Department of Immunology, School of Medicine, Wuhan University, Wuhan, PR China.
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000235:genetics* / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology; D049109:Cell Proliferation; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics* / Q000276:immunology; D006367:HeLa Cells; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D008168:Lung / Q000473:pathology; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000276:immunology*; D011897:Random Allocation; D013154:Spleen / Q000166:cytology; D014376:Tuberculosis / Q000276:immunology / Q000517:prevention & control; D032581:Tuberculosis Vaccines / Q000276:immunology* / Q000592:standards; D019444:Vaccines, DNA / Q000276:immunology* / Q000592:standards
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; D032581:Tuberculosis Vaccines; D019444:Vaccines, DNA; D007371:Interferon-gamma