Detection of primary target cells for HIV-1 in skin explant model and the functional role of HIV infected DC

我们使用皮肤外植体模型系统研究了用于获得HIV感染的相关宿主分子靶点。将HIV&lt；Bal&gt；涂抹在皮肤外植体磨损的表皮表面。3天后，取皮肤外植体的移植物细胞与同种异体T细胞共培养。用酶联免疫吸附试验检测培养上清液中HIV p24的水平。有趣的是，皮肤外植体与PSC-RANTES预先孵育后，完全阻止了随后艾滋病毒从移居细胞向T细胞的传播，而甘露聚糖则没有。值得注意的是，当确定单个LC或DC在迁移细胞中的感染水平时，仅在LC中检测到HIV p24细胞，而在DC中未检测到。为了测试HIV是否可以在LC中复制，皮肤外植体暴露在HIV变种中，这些变种被设计成在细胞生产性感染期间表达GFP。当使用CCR5的HIV分离株而不是使用CXCR4的HIV分离株应用于皮肤时，在LC-T细胞结合物中检测到HL A-DR/Langerin/GFP迁移细胞。因此，CCR5介导的产生性HIV对LC的感染，而不是C型凝集素介导的DC对病毒的捕获，可能为了解人类对使用CCR5的HIV毒株初始感染的易感性提供了生物学基础。

We studied relevant host molecular targets utilized for acquisition of HIV infection using a skin explant model system. HIV_<BaL> was applied to the abraded epidermal surface of skin explants. After 3 days, emigrant cells from skin explants were co-cultured with allogeneic T cells. HIV p24 levels in culture supernatants were monitored by ELISA. Interestingly, preincubation of skin explants with PSC-RANTES completely blocked subsequent HIV transmission from emigrant cells to T cells, whereas mannan did not. Strikingly, when infection levels of single LC or DC within emigrant cells were determined, HIV p24+ cells were detected only in LC, but not in DC. To test whether HIV could replicate within LC, skin explants were exposed to HIV variants that were engineered to express GFP during productive infection of cells. HLA-DR+/ Langerin+/ GFP+ emigrated cells were detected in LC-T cell conjugates, when a CCR5-using HIV isolate, but not a CXCR4-using HIV isolate, was applied to skin. Thus, CCR5-mediated productive HIV infection of LC, and not C-type lectin-mediated capture of virus by DC, may provide a biologic basis for understanding susceptibility to initial infection by CCR5-using strains of HIV in humans.