Willey Samantha J, Reeves Jacqueline D, Hudson Richard, Miyake Koichi, Dejucq Nathalie, Schols Dominique, De Clercq Erik, Bell Jeanne, McKnight Aine, Clapham Paul R
Center for AIDS Research, Program in Molecular Medicine, Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester 01605, USA.
J Virol. 2003 Jun;77(11):6138-52. doi: 10.1128/jvi.77.11.6138-6152.2003.
The chemokine receptors CCR5 and CXCR4 are the major coreceptors for human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). At least 12 other chemokine receptors or close relatives support infection by particular HIV and SIV strains on CD4(+) transformed indicator cell lines in vitro. However, the role of these alternative coreceptors in vivo is presently thought to be insignificant. Infection of cell lines expressing high levels of recombinant CD4 and coreceptors thus does not provide a true indication of coreceptor use in vivo. We therefore tested primary untransformed cell cultures that lack CCR5 and CXCR4, including astrocytes and brain microvascular endothelial cells (BMVECs), for naturally expressed alternative coreceptors functional for HIV and SIV infection. An adenovirus vector (Ad-CD4) was used to express CD4 in CD4(-) astrocytes and thus confer efficient infection if a functional coreceptor is present. Using a large panel of viruses with well-defined coreceptor usage, we identified a subset of HIV and SIV strains able to infect two astrocyte cultures derived from adult brain tissue. Astrocyte infection was partially inhibited by several chemokines, indicating a role for the chemokine receptor family in the observed infection. BMVECs were weakly positive for CD4 but negative for CCR5 and CXCR4 and were susceptible to infection by the same subset of isolates that infected astrocytes. BMVEC infection was efficiently inhibited by the chemokine vMIP-I, implicating one of its receptors as an alternative coreceptor for HIV and SIV infection. Furthermore, we tested whether the HIV type 1 and type 2 strains identified were able to infect peripheral blood mononuclear cells (PBMCs) via an alternative coreceptor. Several strains replicated in Delta32/Delta32 CCR5 PBMCs with CXCR4 blocked by AMD3100. This AMD3100-resistant replication was also sensitive to vMIP-I inhibition. The nature and potential role of this alternative coreceptor(s) in HIV infection in vivo is discussed.
趋化因子受体CCR5和CXCR4是人类免疫缺陷病毒（HIV）和猿猴免疫缺陷病毒（SIV）的主要共受体。至少还有12种其他趋化因子受体或其近亲在体外能支持特定HIV和SIV毒株对CD4(+)转化指示细胞系的感染。然而，目前认为这些替代共受体在体内的作用微不足道。因此，在表达高水平重组CD4和共受体的细胞系上进行感染，并不能真实反映体内共受体的使用情况。我们因此检测了缺乏CCR5和CXCR4的原代未转化细胞培养物，包括星形胶质细胞和脑微血管内皮细胞（BMVEC），以寻找对HIV和SIV感染具有功能的天然表达的替代共受体。使用腺病毒载体（Ad-CD4）在CD4(-)星形胶质细胞中表达CD4，因此如果存在功能性共受体，就能实现高效感染。我们使用了一大组具有明确共受体使用情况的病毒，鉴定出了能够感染源自成体脑组织的两种星形胶质细胞培养物的HIV和SIV毒株子集。几种趋化因子部分抑制了星形胶质细胞的感染，表明趋化因子受体家族在观察到的感染中发挥了作用。BMVEC的CD4呈弱阳性，但CCR5和CXCR4呈阴性，并且对感染星形胶质细胞的同一毒株子集敏感。趋化因子vMIP-I有效抑制了BMVEC的感染，表明其一种受体是HIV和SIV感染的替代共受体。此外，我们检测了鉴定出的1型和2型HIV毒株是否能够通过替代共受体感染外周血单核细胞（PBMC）。几种毒株在Delta32/Delta32 CCR5 PBMC中复制，其中CXCR4被AMD3100阻断。这种对AMD3100耐药的复制也对vMIP-I抑制敏感。本文讨论了这种替代共受体在体内HIV感染中的性质和潜在作用。
