Delézay O, Koch N, Yahi N, Hammache D, Tourres C, Tamalet C, Fantini J
Laboratoire de Biochimie et Biologie de la Nutrition, URA-CNRS 1820, Faculté des Sciences de St Jérôme, Marseille, France.
AIDS. 1997 Sep;11(11):1311-8. doi: 10.1097/00002030-199711000-00004.
To detect the expression CXCR4/fusin in human intestinal epithelial cells and to assess its potential role in the pathway of HIV-1 infection mediated by the alternative gp120 receptor galactosylceramide (GalCer).
GalCer+ (HT-29, HT-29/CD4+) and GalCer- (Caco-2/Cl2, Cl14 and Cl14/CD4+) human intestinal cell lines were analysed for CXCR4/fusin expression using the monoclonal antibody (MAb) 12G5. This MAb was then evaluated for its ability to inhibit HIV-1 infection in permissive cells. HIV-1 infection was measured by detection of p24 antigen, polymerase chain reaction amplification, and cocultivation with CD4+ cells.
CXCR4/fusin was detected on the surface of HT-29 and HT-29/CD4+, but not on Caco-2/Cl2, Cl14 and Cl14/CD4+ cells. Ninety per cent of CXCR4/fusin+ HT-29 and HT-29/CD4+ cells co-expressed GalCer. Infection of HT-29 cells by laboratory isolates of HIV-1 was inhibited by both anti-GalCer and anti-CXCR4/fusin MAbs. Expression of CD4 rendered HT-29 cells sensitive to HIV-1(89.6), a macrophage-tropic isolate that does not recognize GalCer. The 12G5 MAb blocked HIV-1 infection of HT-29/CD4+ cells. In contrast, the expression of HIV-1 receptors, i.e., CD4 GalCer or both, into CXCR4/fusin-negative intestinal cells did not confer sensitivity to HIV-1 infection. The resulting receptor-positive cell lines could, however, bind HIV-1, whereas the original cell lines could not.
HIV-1 entry into human intestinal cells involves both GalCer and CXCR4/fusin. HIV-1 isolates such as 89.6 that are able to use CXCR4/fusin as coreceptor, but do not bind to GalCer, do not infect these cells. These data raise the possibility that CXCR4/fusin may function as a coreceptor for HIV-1 entry into CD4-/GalCer+ intestinal epithelial cells.
检测人肠道上皮细胞中CXCR4/fusin的表达，并评估其在由替代gp120受体半乳糖神经酰胺（GalCer）介导的HIV-1感染途径中的潜在作用。
使用单克隆抗体（MAb）12G5分析GalCer+（HT-29、HT-29/CD4+）和GalCer-（Caco-2/Cl2、Cl14和Cl14/CD4+）人肠道细胞系中CXCR4/fusin的表达。然后评估该单克隆抗体抑制允许性细胞中HIV-1感染的能力。通过检测p24抗原、聚合酶链反应扩增以及与CD4+细胞共培养来测量HIV-1感染。
在HT-29和HT-29/CD4+细胞表面检测到CXCR4/fusin，但在Caco-2/Cl2、Cl14和Cl14/CD4+细胞表面未检测到。90%的CXCR4/fusin+ HT-29和HT-29/CD4+细胞共表达GalCer。抗GalCer和抗CXCR4/fusin单克隆抗体均抑制HIV-1实验室分离株对HT-29细胞的感染。CD4的表达使HT-29细胞对HIV-1（89.6）敏感，HIV-1（89.6）是一种不识别GalCer的巨噬细胞嗜性分离株。12G5单克隆抗体阻断HT-29/CD4+细胞的HIV-1感染。相反，将HIV-1受体，即CD4、GalCer或两者，导入CXCR4/fusin阴性的肠道细胞中并不能使细胞对HIV-1感染敏感。然而，由此产生的受体阳性细胞系能够结合HIV-1，而原始细胞系则不能。
HIV-1进入人肠道细胞涉及GalCer和CXCR4/fusin。能够将CXCR4/fusin用作共受体但不与GalCer结合的HIV-1分离株，如89.6，不会感染这些细胞。这些数据增加了CXCR4/fusin可能作为HIV-1进入CD4-/GalCer+肠道上皮细胞的共受体发挥作用的可能性。
