Dichotomy of the Human T cell response to Leishmania Antigens. I. Thl-like Response to Leishmania major Promastigote Antigens in Individuals Recovered from Cutaneous Leishmaniasis

Abstract

The T ceil response to antigens from Lei.shtnania major promastigoles was investigated in peripheral biood mononuclear cells from Sudanese individuals with a history of cutaneous leishmaniasis (CL), Sudanese individuals with positive DTH reaction in the leishmanin skin test but wilh no history of skin lesions, and in Danes without known exposure to Leishmania parasites. Proliferation and production of interferon-gamma (IF''N-7) and IL-4 in aniigen-stimulaied eultures was measured. Lymphocytes from individuals with a history of CL proliferated vigorously and produced IFN-7 afler stimulation with either a crude preparation of L. major antigens or the major surface protease gp63. These cullures produced no or onty little IL-4. Also celis from leishmanin skin test-positive donors wilh no history of CL produced IFN-7 and no lL-4 in response to /,. major antigens. Cells from the unexposed Danes were nol activated by gp63. The cells from Danish donors produced either IFN-7 or IL-4, but not bolh cytokines after incubation with the crude preparation of L. major antigens. The dala show that the T cell response to Leishmania antigens in humans who have had uncomplicated CL or subelinical L. major infection is an IFN-7-producing Thl-like response.