Immunologic unresponsiveness in leprosy is mediated by modulation of E-receptor

Abstract

By using an indirect immunofluorescence technique with OKT₃ and OKT₁₁ monoclonal antibodies, the percentage of CD₂ positive cells was found to be reduced in the peripheral blood of bacterial index positive lepromatous leprosy patients; however, in these patients, CD₃ positive cells were at the normal level. Further, CD₂ positive cells attained the normal proportion in lepromatous patients when mycobacterial load was reduced. Both CD₂ and CD₃ receptors were expressed at the normal level in tuberculoid leprosy patients. Prior treatment of peripheral blood mononuclear cells from healthy controls with Mycobacterium leprae significantly decreased the percentage of CD₂ but not CD₃ positive cells. Such a modulation of CD₂ on T cells also resulted in blocking the lymphoproliferative response induced by mitogen and antigen. These results suggest that there is a strong correlation between CD₂ modulation and immunologic unresponsiveness in leprosy.