Trypanosoma cruzi modulates the profile of memory CD8+ T cells in chronic Chagas’ disease patients. Int. Immunol

We present a cross-sectional analysis of the maturation and migratory properties of the memory CD81 T cell compartment, in relation to the severity of heart disease in individuals with chronic Trypanosoma cruzi infection removed from endemic areas for longer than 20 years. Subjects with none or mild heart involvement were more likely to mount T. cruzi-specific memory IFN-c responses than subjects with more advanced cardiac disease, and the T. cruzi-specific CD81 T cell population was enriched in early-differentiated (CD271CD281) cells in responding individuals. In contrast, the frequency of CD271CD281CD81 T cells in the total memory CD81 T cell population decreases, as disease becomes more severe, while the proportion of fully differentiated memory (CD27CD28) CD81 T cells increases. The analysis of CCR7 expression revealed a significant increase in total effector/memory CD81 T cells (CD45RACCR7) in subjects with mild heart disease as compared with uninfected controls. Altogether, these results are consistent with the hypothesis of a gradual clonal exhaustion in the CD81 T cell population, perhaps as a result of continuous antigenic stimulation by persistent parasites