Immunogenicity analysis of HIV vaccine based on replicating vaccinia virus Tiantan vector / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the immunogenicity of HIV vaccine vTKgpe based on Vaccinia Virus Tiantan vector in mice and rabbits.</p><p><b>METHODS</b>Mice were inoculated with HIV vaccine vTKgpe by intramuscular (i.m.), intradermal (i.d.) or subcutaneous (s.c.) injections. Blood sample were collected every week, and then antibodies against HIV and vaccinia virus vector were detected. At week 4, some mice were killed and cellular immune responses were examined by flow cytometer. Additionally two rabbits were vaccinated subcutaneously, blood sample were tested as done with mice.</p><p><b>RESULTS</b>In mice i.m. and s.c. groups, HIV specific antibodies emerged at week 2 and declined at week 4. Antibodies against vector elevated rapidly at week 4, and potentially affected HIV specific antibody detection. Cellular immune responses were only detected in s.c. group. Serum of rabbit showed that anti-HIV antibody appeared at week 2 and maintained for several weeks.</p><p><b>CONCLUSION</b>Vaccine vTKgpe innoculated by i.m. and s.c routes inclined to induce humoral immune responses in mice, but in i.d. group, inclined to induce cellular immune responses. Response to the recombinant vaccinia virus was more sensitive in rabbit than in mice.</p>

The construction of attenuated Tiantan recombinant vaccinia virus vector with IFN-gamma receptor gene deletion / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>B8R gene encodes a secreted protein with homology to IFN-gamma receptor, which neutralizes the antiviral and immunological regulation activities of IFN-gamma. To improve the safety of vaccinia virus vector, an attenuated recombinant vaccinia virus with the B8R gene deletion from Tiantan vaccine strain (VTT) was constructed.</p><p><b>METHODS</b>The transfer vectors were generated by joining B8R left flank, B8R right flank, vv promoter, LacZ, multicloning site and pBRSK fragments. The recombinant viruses VTTdeltaB8RLacZ (VTT with B8R deletion and LacZ insertion) were constructed by homologous recombination.</p><p><b>RESULTS</b>The B8R deletion mutants were confirmed by dot blot with B8R gene probe and PCR amplification. The replication ability of VTTdeltaB8RLacZ strain in vitro was similar to that of the VTT. The skin lesions formed by VTTdeltaB8RLacZ (10(6) pfu) were significantly smaller and healed faster than those formed by VTT when injected intradermally to the rabbits,and no visible ulceration occurred. Meanwhile LacZ in VTKgpedeltaB8RLacZ was expressed stably.</p><p><b>CONCLUSIONS</b>The attenuated vector with B8R gene deletion improves the safety of recombinant vaccinia virus vaccine B8R locus may be used as a new site for insertion of foreign genes in vaccinia virus vector.</p>