How T cells identify tuberculosis infected macrophages?

By recognizing Mycobacterium tuberculosis (Mtb) infected macrophages, CD8⁺ T cells defend against the bacterial infection.

The authors investigated how chronic infection affects the diversity of lung parenchymal CD8⁺ T cells. They identify effector and dysfunctional states among lung CD8+ T cells during chronic tuberculosis in C57BL/6 mice.

The most differentially expressed gene between the two states is CD226, which costimulates recognition of infected macrophages.

Loss of CD226 expression correlates with development of CD8+ T cell exhaustion during tuberculosis.

https://www.cell.com/cell-reports/fulltext/S2211-1247(25)00955-6

https://sciencemission.com/CD226-identifies-effector-CD8-T-cells