Reactivation of tuberculosis is associated with a shift from type 1 to type 2 cytokines

The pattern of cytokines produced by T cells from mice with latent tubercul osis and during reactivation of tuberculosis was determined. A type 1 cytok ine pattern was observed in T cells isolated from the lung of mice with lat ent disease. Reactivation of mycobacterial growth, by activation of the hyp othalamic-pituitary-adrenal (HPA) axis, resulted in a shift from a type 1 t o a type 2 cytokine pattern in both CD4 and CD8 T cells. Classification of the T cells based on their differential expression of CD45 and CD44 showed that the phenotypically different populations of CD4 and CD8 cells exhibite d a type 1 cytokine pattern at latency and that reactivation of latent tube rculosis was associated with a shift in cytokines produced by these populat ions to a type 2 cytokine response. Control of mycobacterial growth resulte d in a return to the type 1 cytokine pattern found during latent disease.