Immune system involvement in TB

Tuberculosis is one of the diseases eliminated from occidental countries, even if few cases are reported every year. Granuloma formation into lung is the fundamental characteristics of this disease and the involvement of our immune system in this process is argued since long time. In advance of publication number of Cellular and Molecular Immunology an important paper illustrates how our immune system has a consistent role in granuloma formation and which kind of T cell are involved.

The comparison between blood samples derived from Tuberculosis patients or healthy donors demonstrated that the presence of a special group of T cells – namely the IL 17 producing γδ T cells- in peripheral blood was significantly higher in patients than in healthy donors. In vitro re-stimulation with tuberculosis mycobacterium antigen generated an increase in IFNγ producing T cells ratio in patients than in healthy donors, while the ration of IL17 producing cells was similar within two groups. These data were consistent with other results obtained in mouse model and confirmed the role of IL17 in granuloma formation. The identification of γδ T cells as major IL17 producer may arise some advantages for possible pharmaceutical treatment, but further elucidations are required to better understand all the mechanism at the basis of this complex disease.