Role of CD8(+) T cells in mycobacterial infections

The interaction between IFN-gamma-secreting CD4(+) T cells and macrophages has long been established as integral in the protective immune response aga inst tuberculosis. More recently, evidence from murine experiments and huma n studies has begun to demonstrate an essential role for MHC class I restri cted CD8(+) T cells in this immune response. CD8(+) T cells can produce the protective cytokines IFN-gamma and TNF-alpha in addition to their classica l cytolytic functions. However, the exact protective mechanisms and antigen s recognized by these important cells remain poorly characterized.