Institute of Virology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
Virology. 2012 Nov 10;433(1):73-84. doi: 10.1016/j.virol.2012.07.012. Epub 2012 Aug 5.
Many SIV isolates can employ the orphan receptor GPR15 as coreceptor for efficient entry into transfected cell lines, but the role of endogenously expressed GPR15 in SIV cell tropism is largely unclear. Here, we show that several human B and T cell lines express GPR15 on the cell surface, including the T/B cell hybrid cell line CEMx174, and that GPR15 expression is essential for SIV infection of CEMx174 cells. In addition, GPR15 expression was detected on subsets of primary human CD4(+), CD8(+) and CD19(+) peripheral blood mononuclear cells (PBMCs), respectively. However, GPR15(+) PBMCs were not efficiently infected by HIV and SIV, including cells from individuals homozygous for the defective Δ32 ccr5 allele. These results suggest that GPR15 is coexpressed with CD4 on PBMCs but that infection of CD4(+), GPR15(+) cells is not responsible for the well documented ability of SIV to infect CCR5(-) blood cells.
许多 SIV 分离株可以利用孤儿受体 GPR15 作为辅助受体，有效地进入转染的细胞系，但内源性表达的 GPR15 在 SIV 细胞嗜性中的作用在很大程度上尚不清楚。在这里，我们表明，几种人 B 和 T 细胞系在细胞表面表达 GPR15，包括 T/B 细胞杂交细胞系 CEMx174，并且 GPR15 表达对于 SIV 感染 CEMx174 细胞是必需的。此外，在人外周血单核细胞（PBMC）的亚群中检测到 GPR15 的表达，分别为 CD4(+)、CD8(+)和 CD19(+)。然而，GPR15(+) PBMC 不能有效地被 HIV 和 SIV 感染，包括来自纯合缺陷 Δ32 ccr5 等位基因个体的细胞。这些结果表明，GPR15 与 PBMC 上的 CD4 共同表达，但 GPR15(+)细胞的感染并不是 SIV 感染 CCR5(-)血细胞的公认能力的原因。
