HLA-DR-restricted peptides identified in the Nef protein can induce HIV type 1-specific IL-2/FN-γ-secreting CD4+ and CD4+/CD8+ T cells in humans after lipopeptide vaccination
HLA-DR-restricted peptides identified in the Nef protein can induce HIV type 1-specific IL-2/FN-γ-secreting CD4+ and CD4+/CD8+ T cells in humans after lipopeptide vaccination
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DOI：
10.1089/aid.2006.0075
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发表时间：
2007-03-01
影响因子：
1.5
通讯作者：
Maillere, Bernard
中科院分区：
文献类型：
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作者：
Gahery, Hanne;Figueiredo, Suzanne;Maillere, Bernard
我们筛选了Neflai蛋白来识别新的HLA-DR限制性表位，因为这种小蛋白在感染的早期表达，而特定的CD4(+)T细胞对于HIV-1感染的有效免疫至关重要。我们合成了一组覆盖Nef蛋白序列的多肽，并用10个常见的HLA-DR分子进行了结合分析。我们在这个蛋白质中定义了四个大区域，能够非常有效地与八个HLADR分子结合。我们利用健康志愿者接种了HIV-1脂肽疫苗，该疫苗包含四个HLADR限制性区域中的三个，以调查他们刺激T细胞的能力。在11名接种疫苗的志愿者中，根据他们的II类分子进行分型，我们能够将疫苗序列与特定的人类白细胞抗原-DR分子结合活性和诱导CD4(+)T细胞增殖联系起来。为了确定潜在的HLA-DR表位，我们合成了31个15聚体的多肽，发现其中26个与一个或多个HLA-DR分子结合。有趣的是，在鉴定的26个15聚体多肽中，有12个包含在脂肽序列中。我们使用干扰素-伽马ELISPOT和流式细胞仪分析来研究这些潜在的CD4(+)T细胞表位诱导特异性T细胞反应的能力。我们发现，这些多肽中的7个能够刺激6名受试志愿者中的5名产生HIV特异性T细胞反应。这些细胞是Nef特异性的CD4(+)和CD4(+)CD8(+)T细胞，单独分泌IL-2/INF-γ或IL-2。总之，这26个Nef人类白细胞抗原-DR限制性多肽可能有助于更好地评估HIV感染中的CD4(+)缺陷，并有助于新的疫苗设计。
We screened the Neflai protein to identify new HLA-DR-restricted epitopes, because this small protein is expressed early during infection, and specific CD4(+) T cells are critical for effective immunity in HIV-1 infection. We synthesized a set of peptides that covers the sequence of the Nef protein, and performed binding assays using 10 common HLA-DR molecules. We defined four large regions in this protein able to bind very efficiently to eight HLADR molecules. We took advantage of healthy volunteers immunized with an HIV-1 lipopeptide vaccine that contains three of the four HLA DR-restricted regions to investigate their capacities to stimulate T cells. In 11 vaccinated volunteers, typed for their class II molecules, we were able to correlate sequences of the vaccine displaying binding activities to specific HLA-DR molecules and the induction of CD4(+) T cell proliferation. To identify potential HLA-DR epitopes, we synthesized 31 15-mer peptides and showed that 26 bound to one or more HLA- DR molecules. Interestingly, 12 of the 26 15-mer peptides identified are included in the sequence of lipopeptides. We used IFN-gamma ELISPOT and flow cytometer assays to investigate the capacity of these potential CD4(+) T cell epitopes to induce specific T cell responses. We showed that seven of these peptides were able to stimulate HIV-specific T cell responses in five of six tested volunteers. These cells are Nef-specific CD4(+) and CD4(+) CD8(+) Tcells secreting IL-2/INF-gamma or IL-2 alone. To conclude, these 26 Nef HLA- DR-restricted peptides could be helpful to better evaluate CD4(+) deficiencies in HIV infection and, for new vaccine designs.