Identification and clinical relevance of naturally occurring human CD8+HLA-DR+ regulatory T cells

LOURDES ARRUVITO; FLORENCIA PAYASLIAN; PLÁCIDA BAZ; ARIEL PODHORZER; ANDRÉS MACHICOTE; ARIEL BILLORDO; JULIETA PANDOLFI; GUILLERMO SEMENIUK; EDUARDO ARRIBALZAGA; LEONARDO FAINBOIM

Mar del Plata

Congreso; LXII Reunión Anual del la Sociedad Argentina de Inmunología - LIX Reunión Científica Anual de la Sociedad Argentina de Investigación Clinica; 2014

Sociedad Argentina de Inmunología y Sociedad Argentina de Investigación Clínica

In 1980, it was reported that a T cell subset induced after T cell activation had very strong suppressor activity, and this function was restricted to T cells expressing HLA-class II- DR antigens. Subsequently, we confirmed that these suppressor cells were CD8+ T cells.Although MHC is known to play a pivotal role in the cellular and humoral immune response by its presentation of peptides to T cells, the expression of HLA-DR on human T cells has been regarded primarily simply as a marker of ?activated? T cells. Recently, HLA-DR expression by human CD4+CD25high T cells was shown to identify a functionally distinct population of mature Tregs. In spite of their previously described potent suppressor T cell capacity, researchers have been reluctant to re-explore the role of CD8+ T cells as Tregs.A high level of tumor-infiltrating CD4+FOXP3+ Tregs was correlated with a shorter time to recurrence in non-small-cell lung cancer (NSCLC). It is also possible that Treg populations other than CD4+FOXP3+ Tregs mediate the suppression of antitumor responses.