Aminooxypentane-RANTES induces CCR5 internalization but inhibits recycling: a novel inhibitory mechanism of HIV infectivity.
Aminooxypentane-RANTES induces CCR5 internalization but inhibits recycling: a novel inhibitory mechanism of HIV infectivity.
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DOI：
10.1084/jem.187.8.1215
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发表时间：
1998-04-20
期刊：
影响因子：
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通讯作者：
Proudfoot AE
中科院分区：
文献类型：
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作者：
Mack M;Luckow B;Nelson PJ;Cihak J;Simmons G;Clapham PR;Signoret N;Marsh M;Stangassinger M;Borlat F;Wells TN;Schlöndorff D;Proudfoot AE
CCR5是一种在T细胞和巨噬细胞上表达的趋化因子受体，是嗜m型HIV-1毒株的主要辅助受体。最近，我们描述了一种nh2末端修饰CCR5配体的激活调节，正常T细胞表达和分泌（RANTES），氨基氧戊烷-RANTES (AOP-RANTES)，在RANTES几乎不起作用的情况下，显示出对巨噬细胞感染HIV-1的有效抑制。为了研究AOP-RANTES抑制HIV感染的机制，我们使用单克隆抗CCR5抗体MC-1检测CCR5的表面表达。我们证明AOP-RANTES能迅速导致CCR5在淋巴细胞、单核/巨噬细胞和CCR5转染的中国仓鼠卵巢（CHO）细胞上的细胞表面表达降低约90%。RANTES也引起细胞表面CCR5的丢失，尽管其影响小于AOP-RANTES。值得注意的是，AOP-RANTES抑制内化CCR5再循环到细胞表面，而RANTES则没有。当外周血单核细胞在RANTES存在下长时间培养时，CCR5的表达与对照培养基处理的细胞相当，而在AOP-RANTES存在下培养的细胞上没有CCR5表面表达。免疫荧光显示，AOP-RANTES和RANTES均诱导细胞表面CCR5下调，并将受体重新分布到含有转铁蛋白受体的内吞细胞器中。当RANTES被移除时，内化受体被循环到细胞表面；然而，在AOP-RANTES存在下内化的受体保留在核内体中。在人骨肉瘤（GHOST） 34/CCR5细胞中，AOP-RANTES和RANTES抑制嗜m型HIV-1毒株SF 162感染的效力与两种趋化因子诱导CCR5下调的程度相关。AOP-RANTES和RANTES在受体下调和再循环作用上的这些差异提示了AOP-RANTES有效抑制HIV感染的机制。此外，这些结果支持了受体内化和受体循环抑制为治疗药物预防HIV感染提供新靶点的观点。
CCR5, a chemokine receptor expressed on T cells and macrophages, is the principal coreceptor for M-tropic HIV-1 strains. Recently, we described an NH2-terminal modification of the CCR5 ligand regulated on activation, normal T cell expressed and secreted (RANTES), aminooxypentane-RANTES (AOP-RANTES), that showed potent inhibition of macrophage infection by HIV-1 under conditions where RANTES was barely effective. To investigate the mechanism of AOP-RANTES inhibition of HIV infectivity we examined the surface expression of CCR5 using a monoclonal anti-CCR5 antibody, MC-1. We demonstrate that AOP-RANTES rapidly caused >90% decrease in cell surface expression of CCR5 on lymphocytes, monocytes/ macrophages, and CCR5 transfected Chinese hamster ovary (CHO) cells. RANTES also caused a loss of cell surface CCR5, although its effect was less than with AOP-RANTES. Significantly, AOP-RANTES inhibited recycling of internalized CCR5 to the cell surface, whereas RANTES did not. When peripheral blood mononuclear cells are cultured for prolonged periods of time in the presence of RANTES, CCR5 expression is comparable to that seen on cells treated with control medium, whereas there is no CCR5 surface expression on cells cultured in the presence of AOP-RANTES. Immunofluorescence indicated that both AOP-RANTES and RANTES induced downmodulation of cell surface CCR5, and that the receptor was redistributed into endocytic organelles containing the transferrin receptor. When RANTES was removed, the internalized receptor was recycled to the cell surface; however, the receptor internalized in the presence of AOP-RANTES was retained in endosomes. Using human osteosarcoma (GHOST) 34/CCR5 cells, the potency of AOP-RANTES and RANTES to inhibit infection by the M-tropic HIV-1 strain, SF 162, correlated with the degree of downregulation of CCR5 induced by the two chemokines. These differences between AOP-RANTES and RANTES in their effect on receptor downregulation and recycling suggest a mechanism for the potent inhibition of HIV infection by AOP-RANTES. Moreover, these results support the notion that receptor internalization and inhibition of receptor recycling present new targets for therapeutic agents to prevent HIV infection.