01577nas a2200313   4500000000100000008004100001260001300042653002700055653004400082653001700126653001600143653001100159653002100170653002400191653001200215653002600227653002500253653003100278653002700309653001800336100002100354700001900375700001800394245008700412300000900499490000700508520073400515022001401249       1988                            d  c1988 Sep10aAntibodies, Monoclonal10aAntigens, Differentiation, T-Lymphocyte10aCD2 Antigens10aCD3 Complex10aHumans10aImmune Tolerance10aIn Vitro Techniques10aleprosy10aLymphocyte Activation10aMycobacterium leprae10aReceptors, Antigen, T-Cell10aReceptors, Immunologic10aT-Lymphocytes1 aMuthukkaruppan V1 aChakkalath H R1 aMalarkannan S00aThe classical and alternate pathways of T cell activation are impaired in leprosy.  a55-80 v193 a<p>The proliferative response of circulating T lymphocytes from bacterial index-positive lepromatous patients to mitogenic anti-CD3 and pairs of anti-CD2 monoclonal antibodies was significantly reduced. In these patients, the CD2 but not CD3 receptor expression was down-regulated. Further, the CD2 modulation and the associated suppression of proliferative response to monoclonals was brought about in T cells of healthy subjects by prior incubation of mononuclear cells in vitro with Mycobacterium leprae. Thus, the T cell activation pathways through the CD3 and CD2 receptors are impaired in lepromatous leprosy patients and the impairment appears to be due to the modulation of the CD2 receptor specifically by M. leprae.</p>  a0165-2478