Identification and Clinical Relevance of Naturally Occurring Human CD8+HLA-DR+ Regulatory T Cells.

ARRUVITO, L; PASYASLIAN, F.; BAZ, P; PODHORZER, A; BILLORDO, A.; PANDOLFI, J; SEMENIUK, G.; ARRIBALZAGA, E.; FAINBOIM, L.

JOURNAL OF IMMUNOLOGY

AMER ASSOC IMMUNOLOGISTS

Lugar: Bethesda; Año: 2014 vol. 4049 p. 4469 - 4476

0022-1767

The lack of responsiveness to self and non-self Ags is normally maintained by multiple mechanisms, including the suppressive activities of several T cell subsets. In this study, we show that CD8(+) T cells from both adult peripheral blood and umbilical cord blood mononuclear cells constitutively expressing HLA-DR represent a natural human CD8(+) regulatory T cell subset. Their suppressive effect appears to be cell-to-cell contact dependent and may involve CTLA-4 signaling between neighboring T cells. These regulatory T cells can be expanded in vitro and exhibit a suppressive capacity similar to that observed in ex vivo CD8(+)HLA-DR(+) T cells. The high frequency of CD8(+)HLA-DR(+) T cells that we detected in patients with non-small cell lung cancer deserves further work to confirm their putative suppressor effect within the tumor.