Study on phenotype and function of antigen-specific CD8+ cytotoxic T cells induced by HPV 16 E7 peptide in vitro / 中华皮肤科杂志

ABSTRACT

Objective To investigate the phenotype and function of antigen-specific CD8+ cytotoxic T cells (CTL) from HLA-A2+ healthy human donors induced by high-carcinogenic HPV 16 E7 peptide in vitro.Methods Peripheral blood T cells from 26 HLA-A2+ healthy human donors were incubated with HPV 16E711-20 peptide (HLA-A*0201/YMLDLQPETT), recombinant human interleukin 7 (IL-7) and IL-2 for 7 days to yield antigen-specific CD8+ CTL. Then, four-color flow cytometric analysis was performed to detect the percentage of antigen-specific CD8+ CTL expressing different surface markers including CD45 and CD27. The expression of three intracellular cytokines including perforin, granzyme-B and FasL in the antigen-specific CD8+ CTL was also measured by intracellular flow cytometry. A wrong peptide, HBVcoxe18-27 (FLPSDFFPSV),was used as an isotype control. Results A significant increase was observed in the percentage of antigen-specific CD8+ CTL in peripheral T cells stimulated with HPV 16 E7-peptide compared with the non-stimulated T cells (0.73% ± 0.33% vs 0.02% ± 0.03%, P ＜ 0.01). The percentage of CD45RA+CD27- effector T cells,CD45RA-CD27- effector memory T (TEM) cells, CD45RA-CD27+ central memory T (TCM) cells, and CD45RA+CD27+ naive T cells in antigen-specific CD8+ CTL was 26.07% ± 13.46%, 7.97% ± 7.11%, 33.25% ± 19.68%and 32.73% ± 13.89%, respectively in HPV 16 E7-stimulated group, significantly higher than that in nonstimulated group (0.02% ± 0.03%, 0.02% ± 0.03%, 0.02% ± 0.03% and 0.02% ± 0.05%, all P ＜ 0.01 ). Elevated proportions of perforin-, granzyme-B- and FasL-expressing antigen specific CTL were observed in HPV 16 E7-stimulated group compared with non-stimulated group (47.01% ± 18.69% vs 0.38% ± 0.55%, 80.53% ±13.32% vs 0.34% ± 0.22%, 26.48% ± 7.81% vs 0.16% ± 0.16%, all P ＜ 0.01 ). Conclusions HPV 16 E7peptide could induce the clonal proliferation of CD8+ T cells, generation of antigen-specific CD8+ CTL and secretion of toxic cytokines, finally lead to a highly efficient and specific killing of virus-infected target cells through different mechanisms, hence, it might play a crucial role in antiviral immune responses.