| Abstract: | In human cutaneous leishmaniasis (CL), the immune response is mainly mediated by
T-cells. The role of CD8+ T-lymphocytes, which are related to healing or
deleterious functions, in affecting clinical outcome is controversial. The aim of
this study was to evaluate T-cell receptor diversity in late-differentiated effector
(LDE) and memory CD8+ T-cell subsets in order to create a profile of
specific clones engaged in deleterious or protective CL immune responses. Healthy
subjects, patients with active disease (PAD) and clinically cured patients were
enrolled in the study. Total CD8+ T-lymphocytes showed a disturbance in
the expression of the Vβ2, Vβ9, Vβ13.2, Vβ18 and Vβ23 families. The analyses of
CD8+T-lymphocyte subsets showed high frequencies of LDE
CD8+T-lymphocytes expressing Vβ12 and Vβ22 in PAD, as well as
effector-memory CD8+ T-cells expressing Vβ22. We also observed low
frequencies of effector and central-memory CD8+ T-cells expressing Vβ2 in
PAD, which correlated with a greater lesion size. Particular Vβ expansions point to
CD8+ T-cell clones that are selected during CL immune responses,
suggesting that CD8+ T-lymphocytes expressing Vβ12 or Vβ22 are involved in
a LDE response and that Vβ2 contractions in memory CD8+T-cells are
associated with larger lesions. |
