V3 CTL epitope density in a single recombinant molecule antigen differentially affects the number and activity of primary and memory CD8+ T cells.
Previous studies have found the close correlation between epitope density and epitope-specific response, which have shown that high epitope density in a single recombinant protein molecule significantly enhances the humoral response and protective immunity. However, it has not been determined whether this kind of high epitope density could also significantly influence T cell response. Based on this, a series of recombinant DNA and proteins were designed and prepared. Each molecule consists of various copy numbers of the V3 CTL epitope on HIV-1 gp120 (one, two, four and eight copies). Our results show clearly that different V3-epitope densities in just one single DNA or protein molecules have respectively different effects on the number and activity of both primary and memory T cells. Interestingly, this effect is more complex than that on the B cells: epitope density in one plasmid or protein antigen affects the number, not the cytotoxic avidity, of primary CD8+ T cells, but affects both the number and cytotoxic avidity of memory CD8+ T cells. It indicates epitope density in the antigen is an important consideration to optimize T cell response induction and may facilitate the development of effective T cell-based anti-virus vaccines.
Lu
Lu
L
Laboratory of Immunology, Department of Biology and Institute of Biomedical Science, Tsinghua University, Protein Science Laboratory of the MOE, Beijing 100084, PR China. chenyh@mail.tsinghua.edu.cn
Zhu
Yun
Y
Diao
Junchen
J
Wang
Zuguang
Z
Chen
Ying-Hua
YH
D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D003601:Cytotoxicity Tests, Immunologic; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D007156:Immunologic Memory / Q000276:immunology*; D018655:Lymphocyte Count; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology
D016915:AIDS Vaccines; D018984:Epitopes, T-Lymphocyte; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D019444:Vaccines, DNA