CCR5 promotes the migration of pathological CD8+ T cells to the leishmanial lesions.

Cytolytic CD8+ T cells mediate immunopathology in cutaneous leishmaniasis without controlling parasites. Here, we identify factors involved in CD8+ T cell migration to the lesion that could be targeted to ameliorate disease severity. CCR5 was the most highly expressed chemokine receptor in patient lesions, and the high expression of CCL3 and CCL4, CCR5 ligands, was associated with delayed healing of lesions. To test the requirement for CCR5, Leishmania-infected Rag1-/- mice were reconstituted with CCR5-/- CD8+ T cells. We found that these mice developed smaller lesions accompanied by a reduction in CD8+ T cell numbers compared to controls. We confirmed these findings by showing that the inhibition of CCR5 with maraviroc, a selective inhibitor of CCR5, reduced lesion development without affecting the parasite burden. Together, these results reveal that CD8+ T cells migrate to leishmanial lesions in a CCR5-dependent manner and that blocking CCR5 prevents CD8+ T cell-mediated pathology.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2024 Amorim Sacramento et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)