HLA-DR-restricted antigen-induced proliferation and cytotoxicity mediated by CD4+ T-cell clones from subjects vaccinated with killed M. leprae.

Thirteen CD4+ T-cell clones raised against Mycobacterium leprae from three M. leprae-vaccinated subjects were studied for major histocompatibility complex (MHC) restriction in proliferative and cytotoxicity assays. These T-cell clones recognized at least nine different epitopes, ranging from M. leprae-specific to broadly crossreactive. Restriction studies with a panel of antigen-presenting cells (APCs) suggest that all of the T-cell clones recognized antigens in the context of the DR locus. Three T-cell clones with three different reactivities from a DR1, 2-positive subject responded to M. leprae in proliferation and cytotoxicity when the antigen was presented in the context of DR1-positive APCs. Four T-cell clones responding to M. leprae-specific or crossreactive epitopes from the second donor, who was DR4,DW4; DR4,Dw14-positive, and a single M. leprae-specific T-cell clone from the third subject, who was DR3,4:Dw4, recognized the antigens in the presence of Dw4 APCs. Four crossreactive T-cell clones from the second subject responded in the presence of Dw14-positive APCs, and one limited crossreactive clone recognized the antigen in the context of DR4 and DR7-positive cells, suggesting that its response was restricted by a common determinant. The T-cell clones that recognize the 65-kDa, 18-kDa, and 13B3 recombinant M. leprae antigens in proliferative assays were cytotoxic for autologous adherent cells pulsed with the respective antigens.(ABSTRACT TRUNCATED AT 250 WORDS)