T-cell receptor Vβ repertoire of CD8⁺ T-lymphocyte subpopulations in cutaneous leishmaniasis patients from the state of Rio de Janeiro, Brazil

• Main Authors: Raquel Ferraz, Clarissa Ferreira Cunha, Maria Inês Pimentel, Marcelo Rosandiski Lyra, Armando Oliveira Schubach, Sérgio Coutinho Furtado de Mendonça, Alda Maria Da-Cruz, Alvaro Luiz Bertho
• Format: Article
• Language: English
• Published: Instituto Oswaldo Cruz, Ministério da Saúde 2015-08-01
• Series: Memórias do Instituto Oswaldo Cruz.
• Subjects: Vβ repertoire; human cutaneous leishmaniasis; flow cytometry; CD8⁺ T-lymphocyte - TCR; Leishmania braziliensis
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762015000500596&lng=en&tlng=en

<p>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.</p>