HUMAN CD4(-)CD8(-) ALPHA-BETA(-CELL RECEPTOR T-CELLS RECOGNIZE DIFFERENT MYCOBACTERIA STRAINS IN THE CONTEXT OF CD1B() T)

Double-negative alpha beta(+) T-cell receptor (TCR) human T cells have been reported to recognize antigen in the context of the HLA class I- like (Ib) CD1 complex. In particular, the CD1b molecule has been shown to act as the element of genetic restriction for antigens derived fro m Mycobacterium tuberculosis. The stenotopic nature of these major his tocompatibility complex (MHC) class Ib molecules raised the question o f whether the antigenic moiety recognized by CD4(-) CD8(-) alpha beta( +) TCR T cells was shared by different mycobacteria. We demonstrate he re that a CD4(-) CD8(-) alpha beta(+) TCR T-cell line and three clones raised against M. tuberculosis proliferated following stimulation wit h soluble extracts from organisms of the M. tuberculosis complex, M. l eprae and 10 out of 16 tested isolates of hi. avium complex; however, four species of weakly or non-pathogenic mycobacteria were not stimula tory. Furthermore, the M. tuberculosis soluble extract (MTSE)-derived, recognized antigenic moiety proved to be proteinase K resistant and t o have a molecular weight greater than 5000 MW, thus it differed from the reported antigenic moiety recognized by CD4(-) CD8(-) gamma delta( +) TCR cells. Our results suggest that a common antigenic moiety, pres ented by CD1b molecules to CD4(-) CD8(-) alpha beta(+) TCR T cells, is shared by many mycobacterial species. Therefore they raise interest i n the question of whether CD4(-) CD8(-) alpha beta(+) TCR T cells, eli cited by M. tuberculosis, may play a role in the natural history of ot her mycobacterial infections.