DeGrendele H C, Kosfiszer M, Estess P, Siegelman M H
Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235, USA.
J Immunol. 1997 Sep 15;159(6):2549-53.
A defining juncture in the life of a T cell is its encounter with its cognate Ag, resulting finally in effector and/or memory T cells known to express, among other characteristics, increased surface levels of CD44. The requirements for the "activation" of CD44 to bind its major ligand, hyaluronan (HA), and the in vivo role of this interaction remain unresolved. We have recently proposed that the CD44/HA interaction is involved in primary lymphocyte adhesion, leading to extravasation at inflammatory sites. We show here that activation of CD44 and ability to engage in rolling occurs directly through polyclonal as well as Ag-specific TCR-initiated signaling. Using a superantigen, it is primarily the Ag-specific activated Vbeta-bearing cells that are induced to bind HA. In addition, this CD44 activation does not appear to be the result of overt changes in glycosylation. These results connect activation of CD44 on T cells with the initiation of immune responses and suggest potential roles for the CD44/HA interaction.
T细胞生命历程中的一个决定性时刻是其与同源抗原的相遇，最终产生效应性和/或记忆性T细胞，这些细胞除了具有其他特征外，还表现出CD44表面水平升高。CD44“激活”以结合其主要配体透明质酸（HA）的要求以及这种相互作用在体内的作用仍未明确。我们最近提出，CD44/HA相互作用参与初始淋巴细胞黏附，导致在炎症部位渗出。我们在此表明，CD44的激活和进行滚动的能力直接通过多克隆以及抗原特异性TCR启动的信号传导发生。使用超抗原时，主要是抗原特异性激活的携带Vβ的细胞被诱导结合HA。此外，这种CD44激活似乎不是糖基化明显变化的结果。这些结果将T细胞上CD44的激活与免疫反应的启动联系起来，并提示了CD44/HA相互作用的潜在作用。
