Wentworth P A, Steimer K S
Chiron Corporation, Emeryville, CA 94608.
Vaccine. 1994 Aug;12(10):885-94. doi: 10.1016/0264-410x(94)90030-2.
We have described previously the generation of seven HIV-SF2 Nef-specific, CD4+ T-cell clones, identification of epitopes within which are recognized by these clones, and the MHC alleles that restrict their responses. In this study, we have extended this characterization to include evaluation of antigen-processing and presentation requirements and cytotoxic activity. Clones were generated from five HIV-1 uninfected donors by in vitro stimulation of peripheral blood mononuclear cells with purified recombinant Nef1. In experiments with fixed cells, with the exception of two clones, recognition of Nef, but not Nef peptides, required processing. Also, at higher concentrations of antigen, the clones themselves were capable of presenting Nef peptides, but not soluble Nef. All clones had the ability to specifically lyse autologous, Epstein-Barr virus-transformed lines sensitized with Nef synthetic peptides, or, in some cases, soluble Nef. The cytotoxic activity mapped to the same epitopes identified for the proliferative response (a.a. 14-22, 47-53, 68-77, 70-77, 195-203 and 185-192) and was restricted by the same HLA class II molecules (DRw6, DQw7, DRw15(2), DR1 and DP5). Sensitization of the cytolytic clones with specific Nef peptides, but not soluble Nef, resulted in autolysis.
我们之前已经描述了7个HIV-SF2 Nef特异性CD4+ T细胞克隆的产生、这些克隆所识别的表位的鉴定以及限制其反应的MHC等位基因。在本研究中，我们扩展了这一特征描述，包括对抗原加工和呈递要求以及细胞毒性活性的评估。通过用纯化的重组Nef1体外刺激外周血单核细胞，从5名未感染HIV-1的供体中产生克隆。在固定细胞的实验中，除了两个克隆外，对Nef的识别（而非对Nef肽的识别）需要加工。此外，在较高抗原浓度下，这些克隆自身能够呈递Nef肽，但不能呈递可溶性Nef。所有克隆都有能力特异性裂解用Nef合成肽或在某些情况下用可溶性Nef致敏的自体EB病毒转化细胞系。细胞毒性活性映射到为增殖反应所确定的相同表位（氨基酸14 - 22、47 - 53、68 - 77、70 - 77、195 - 203和185 - 192），并受到相同的HLA - II类分子（DRw6、DQw7、DRw15(2)、DR1和DP5）的限制。用特异性Nef肽而非可溶性Nef致敏溶细胞克隆会导致自溶。
