Increased activation and expansion of a CD57+ subset within peripheral CD8+ T lymphocytes in Mycobacterium tuberculosis-infected patients.

Background: Mycobacterium tuberculosis-specific CD8+ and CD4+ T lymphocyte responses restrict the spread of extracellular pathogens by limiting M.tuberculosis replication. Alterations in cytolytic function, inappropriate maturation/differentiation, and limited proliferation could reduce their ability to control M.