Mukasa R, Homma T, Ohtsuki T, Hosono O, Souta A, Kitamura T, Fukuda M, Watanabe S, Morimoto C
Department of Clinical Immunology and AIDS Research Center, Institute of Medical Science, University of Tokyo, Japan.
Int Immunol. 1999 Feb;11(2):259-68. doi: 10.1093/intimm/11.2.259.
Human CD4 T cells can be divided into two functionally distinct subsets: a CD45RO+ memory subset and a CD45RA+ naive subset. In an attempt to identify novel cell surface molecules on these cells, we have developed a mAb, anti-1D4. The antigen defined by anti-1D4 was preferentially expressed on the memory subset of freshly isolated peripheral CD4 T cells and 1D4+ CD4 T cells functionally corresponded to memory T cells. Retrovirus-mediated expression cloning revealed that the 1 D4 antigen is human CD43. Transfection of CHO-leu cells, which stably express human CD43, with core 2 beta-1,6-N-acetylglucosaminyltransferase (C2GnT) conferred expression of the 1D4 antigen and mRNA of C2GnT was detected by RT-PCR only in 1D4+ T cells but not in 1D4- T cells, implying that the 1 D4 antigen is composed of core 2-containing O-glycans on CD43. Reactivity with anti-1 D4 was completely abolished when cells were treated with neuraminidase, while them remained weak binding of anti-T305, a previously described mAb which also reacts with CD43 modified with core 2-containing O-glycans. Moreover, anti-1D4 markedly reacted with NIH-3T3 cells expressing human CD43 and low levels of endogenous C2GnT, whereas anti-T305 reacted slightly. These results indicate that the 1D4 antigen is distinct from the epitope defined by anti-T305 and anti-1D4 is a more sensitive probe to detect core 2-containing O-glycans than anti-T305. Taken together, our results indicate that core 2-containing O-glycans, whose expression can easily be detected with anti-1D4, are preferentially expressed in the CD45RO+ memory subset of CD4 T cells.
人CD4 T细胞可分为两个功能不同的亚群：CD45RO +记忆亚群和CD45RA +初始亚群。为了鉴定这些细胞上的新型细胞表面分子，我们制备了一种单克隆抗体，抗-1D4。抗-1D4所定义的抗原优先表达于新鲜分离的外周血CD4 T细胞的记忆亚群上，且1D4 + CD4 T细胞在功能上与记忆T细胞相对应。逆转录病毒介导的表达克隆显示，1D4抗原是人CD43。用核心2β-1,6-N-乙酰葡糖胺基转移酶（C2GnT）转染稳定表达人CD43的CHO-leu细胞，可使1D4抗原表达，且仅在1D4 + T细胞中通过RT-PCR检测到C2GnT的mRNA，而在1D4 - T细胞中未检测到，这意味着1D4抗原由CD43上含核心2的O-聚糖组成。当细胞用神经氨酸酶处理时，与抗-1D4的反应性完全消失，而抗-T305（一种先前描述的也与含核心2的O-聚糖修饰的CD43反应的单克隆抗体）仍保持弱结合。此外，抗-1D4与表达人CD43和低水平内源性C2GnT的NIH-3T3细胞有明显反应，而抗-T305反应较弱。这些结果表明，1D4抗原与抗-T305所定义的表位不同，且抗-1D4是比抗-T305更敏感的检测含核心2的O-聚糖的探针。综上所述，我们的结果表明，其表达可用抗-1D4轻易检测到的含核心2的O-聚糖优先表达于CD4 T细胞的CD45RO +记忆亚群中。
