Functional characterization of a T‐cell receptor BV6 + T‐cell clone derived from a leprosy lesion

Summary Human infection with Mycobacterium leprae , an intracellular bacterium, presents as a clinical and immunological spectrum; thus leprosy provides an opportunity to investigate mechanisms of T‐cell responsiveness to a microbial pathogen. Analysis of the T‐cell receptor (TCR) repertoire in leprosy lesions revealed that TCR BV6 + T cells containing a conserved CDR3 motif are over‐represented in lesions from patients with the localized form of the disease. Here, we derived a T‐cell clone from a leprosy lesion that expressed TCR BV6 and the conserved CDR3 sequence L‐S‐G. This T‐cell clone produced a T helper type 1 cytokine pattern, directly lysed M. leprae ‐pulsed antigen‐presenting cells by the granule exocytosis pathway, and expressed the antimicrobial protein granulysin. BV6 + T cells may therefore functionally contribute to the cell‐mediated immune response against M. leprae .