Granulysin-dependent killing of intracellular and extracellular Mycobacterium tuberculosis by V-γ9/Vδ2 T lymphocytes

Abstract

Contribution of Vγ9/Vδ2 T lymphocytes to immune protection against Mycobacterium tuberculosis is still a matter of debate. It was reported earlier that Vγ9/Vδ2 T lymphocytes kill macrophages harboring live M. tuberculosis through a granule-dependent mechanism that results in killing of intracellular bacilli. This study found that Vγ9/Vδ2 T lymphocytes reduce the viability of both extracellular and intracellular M. tuberculosis. Granulysin and perforin, both detected in Vγ9/Vδ2 T lymphocytes, play a major role, which indicates that Vγ9/Vδ2 T lymphocytes directly contribute to a protective host response against M. tuberculosis infection.