Mathew Stephen O, Vaidya Swapnil V, Kim Jong R, Mathew Porunelloor A
Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
Biochem Biophys Res Commun. 2007 Apr 6;355(2):483-7. doi: 10.1016/j.bbrc.2007.01.176. Epub 2007 Feb 7.
2B4 (CD244), a member of the CD2 subset of the immunoglobulin superfamily, is important for stimulating human natural killer (NK) cell cytotoxicity and cytokine production. It is expressed on all NK cells, a subpopulation of T cells, monocytes, basophils and eosinophils. 2B4 interaction with its ligand CD48 regulates NK, T and B lymphocyte functions and thus plays a central role in various immune responses. Previous study indicated a role for AP-1 and Ets in the transcription of the 2B4 gene. In this study we report that stimulation of NK cells through surface 2B4 down-regulates its own expression due to a reduction in the promoter activity at the Ets element. The down-regulation of 2B4 could be a mechanism to attenuate the co-stimulatory signal from 2B4--CD48 interactions.
2B4（CD244）是免疫球蛋白超家族CD2亚群的成员，对刺激人类自然杀伤（NK）细胞的细胞毒性和细胞因子产生具有重要作用。它在所有NK细胞、T细胞亚群、单核细胞、嗜碱性粒细胞和嗜酸性粒细胞上表达。2B4与其配体CD48的相互作用调节NK、T和B淋巴细胞的功能，因此在各种免疫反应中起核心作用。先前的研究表明AP-1和Ets在2B4基因的转录中起作用。在本研究中，我们报告通过表面2B4刺激NK细胞会下调其自身表达，这是由于Ets元件处的启动子活性降低所致。2B4的下调可能是减弱来自2B4 - CD48相互作用的共刺激信号的一种机制。
