01510nas a2200229   4500000000100000008004100001260001300042653002100055653003700076653002500113653001600138653002500154653001800179100001300197700001400210245009000224300001100314490000700325050001300332520092100345022001401266       1988                            d  c1988 Aug10aImmune Tolerance10aImmunologic Deficiency Syndromes10aLeprosy, lepromatous10aMacrophages10aMycobacterium leprae10aT-Lymphocytes1 aBach M A1 aLaunois P00aMechanisms of Mycobacterium leprae-specific T-cell deficiency in lepromatous leprosy.  a1013-80 v70  aBACH19883 a<p>Patients suffering from lepromatous leprosy fail to develop an efficient cell-mediated immunity towards Mycobacterium leprae, the causative agent. The mechanism of such a specific T-cell tolerance to the bacillus remains a key question in the pathophysiology of leprosy. Macrophages do not show any intrinsic defect in phagocytizing and killing M. leprae or in presenting antigen to helper T-cells. On the other hand, M. leprae-reactive helper T-cells do persist in lepromatous patients, but their activation appears to prevented by active suppressor mechanisms, involving both suppressor T-cells and macrophages. The target of this specific suppression could be the interleukin 2-producing T-cell subset. A better molecular definition of M. leprae antigens, both by monoclonal antibodies and T-cell clones, should open new perspectives for further analysis of the regulation of immune responses to M. leprae.</p>  a0300-9084