Inoue M, Hoshino T, Fukuma T, Niwa Y, Kido H
Department of Parasitology, Kurume University School of Medicine, Fukuoka, Japan.
Biochem Biophys Res Commun. 1994 Jun 30;201(3):1390-5. doi: 10.1006/bbrc.1994.1857.
Tryptase TL2, a serine esterase in the membrane of human monocytoid and CD4+ lymphoid cells, specifically binds to the V3 domain of HIV-1 gp120. Here we report that monoclonal antibodies against CD4 that recognize the epitope interacting with gp120 specifically blocked the immunostaining of cell-surface tryptase TL2, although the antibody does not cross-react with tryptase TL2. Down-regulation of cell-surface CD4 induced by HIV-1 Nef prevented this blocking effect. These data suggest that CD4 is closely co-localized with tryptase TL2 on the cell surface and that regulation of the expression of tryptase TL2 is not associated with that of CD4.
类胰蛋白酶TL2是一种存在于人类单核细胞样细胞和CD4 + 淋巴细胞细胞膜中的丝氨酸酯酶，它能特异性结合HIV-1 gp120的V3结构域。在此我们报告，识别与gp120相互作用表位的抗CD4单克隆抗体可特异性阻断细胞表面类胰蛋白酶TL2的免疫染色，尽管该抗体与类胰蛋白酶TL2无交叉反应。HIV-1 Nef诱导的细胞表面CD4下调可阻止这种阻断作用。这些数据表明，CD4在细胞表面与类胰蛋白酶TL2紧密共定位，且类胰蛋白酶TL2表达的调节与CD4的调节无关。
