Enhanced induction of SARS-CoV nucleocapsid protein-specific immune response using DNA vaccination followed by adenovirus boosting in BALB/c mice.
OBJECTIVE
To investigate immunogenicity in the induction of humoral and cellular immune responses to genetic vaccines of the recombinant severe acute respiratory syndrome-associated coronavirus (SARS-CoV)-N gene expressing the same protein plasmid, pcDNA3.1-N, and replication-defective adenoviral vector, rAd-N, in a pcDNA3.1-N prime-rAd-N boost regimen and the reverse sequence in a rAd-N prime-pcDNA3.1-N boost regimen.


METHODS
After the mice had been immunized intramuscularly and/or intraperitoneally with pcDNA3.1-N and rAd-N in prime-triple boost immunization, humoral and cellular immune responses were detected.


RESULTS
After detection, different levels of anti-N humoral and cellular responses are shown compared to controls. The humoral immune response was induced more effectively by the DNA priming and recombinant adenovirus boosting regimen and the reverse sequence of heterogeneous combinations. There is a significant difference between heterogeneous and homologous vaccinations. However, the cytotoxic T lymphocyte (CTL) response was not significantly altered by the different prime-boost immunizations or the recombinant adenovirus of pcDNA3.1-N prime-rAd-N boost regimen alone, but lymphoproliferation and interferon-gamma (IFN-gamma) secretion were all enhanced by heterologous combination immunizations compared to homologous combinations. For the reverse sequence immunization regimen, lymphoproliferation, IFN-gamma and CTL responses were all significantly weaker compared with pcDNA3.1-N prime-rAd-N boost regimen.


CONCLUSIONS
Taken together, of all the combinations, the prime-triple boost immunization of pcDNA3.1-N/pcDNA3.1-N/pcDNA3.1-N/rAd-N can effectively induce SARS-CoV-N-specific and strong humoral and cellular immune responses in mice. The present results suggest that DNA immunization followed by recombinant adenovirus boosting could be used as a potential SARS-CoV vaccine in the induction of an enhanced humoral and cellular immune response.
Chunling
Ma
M
Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, PR China.
Kun
Yao
Y
Jian
Xu
X
Jian
Qin
Q
Hua
Sun
S
Minsheng
Zhu
Z
D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D000086462:Coronavirus Nucleocapsid Proteins; D003602:Cytotoxicity, Immunologic; D005260:Female; D005822:Genetic Vectors; D007114:Immunization; D007115:Immunization Schedule; D007273:Injections, Intramuscular; D007274:Injections, Intraperitoneal; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D019590:Nucleocapsid Proteins / Q000276:immunology* / Q000378:metabolism; D016865:Reassortant Viruses; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology*; D045169:Severe Acute Respiratory Syndrome / Q000097:blood / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
D000914:Antibodies, Viral; D000086462:Coronavirus Nucleocapsid Proteins; D019590:Nucleocapsid Proteins; D019444:Vaccines, DNA; D014765:Viral Vaccines