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

我们利用皮肤外植体模型系统研究了获得HIV感染的相关宿主分子靶点。将HIV_< bal>应用于皮肤外植体擦伤的表皮表面。3天后，将皮肤外植体的移行细胞与异体T细胞共培养。ELISA法检测培养上清液中HIV p24水平。有趣的是，用PSC-RANTES预孵育的皮肤外植体完全阻断了随后HIV从迁移细胞向T细胞的传播，而甘露聚糖则没有。引人注目的是，当确定迁移细胞内单个LC或DC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，皮肤外植体暴露于在细胞生产感染期间表达GFP的HIV变体中。当将使用ccr5的HIV分离物而不是使用cxcr4的HIV分离物应用于皮肤时，在LC-T细胞偶联物中检测到HLA-DR+/ Langerin+/ GFP+迁移细胞。因此，ccr5介导的LC的生产性HIV感染，而不是c型凝集素介导的DC对病毒的捕获，可能为理解使用ccr5的人类HIV毒株对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.