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

我们使用皮肤移植模型系统研究了用于获得HIV感染的相关宿主分子靶标。将HIV_<BaL>应用于皮肤外植体的磨损的表皮表面。3天后，将来自皮肤外植体的移出细胞与同种异体T细胞共培养。通过ELISA监测培养上清液中的HIV p24水平。有趣的是，用PSC-RANTES预孵育皮肤外植体完全阻断了随后的HIV从迁移细胞到T细胞的传播，而甘露聚糖没有。引人注目的是，当确定单个LC或DC在迁移细胞内的感染水平时，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内复制，将皮肤外植体暴露于经工程改造以在细胞的生产性感染期间表达GFP的HIV变体。当将使用CCR 5的HIV分离株而不是使用CXCR 4的HIV分离株应用于皮肤时，在LC-T细胞缀合物中检测到HLA-DR+/ Langerin+/ GFP+迁移细胞。因此，CCR 5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，可能为理解人类中使用CCR 5的HIV株对初始感染的易感性提供生物学基础。

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.