High frequency and phenotype characteristics of liver CD8+HLA-DR+ Treg cells: potential role of IFN-γ

A MACHICOTE; S BELEN; A BILLORDO; P BAZ; L ARRUVITO; L FAINBOIM

Mar del Plata

Encuentro; LXIV Reunión Anual de la Sociedad Argentina de Inmunología; 2016

Sociedad Argentina de Inmunología

We have shown 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 (CD8+DR+Tregs), acting through cell-cell contact and the participation of CTLA-4. The liver shows a high frequency of CD8+ cells, including those expressing HLA-DR.The aim was to investigate the difference in phenotypes of CD8+ cells from peripheral blood and liver, focusing on their role in the modulation of the hepatic immune response.The differential phenotype of CD8+HLA-DR+ and CD8+HLA-DR- in blood (n=16) and liver perfusion (n=13) was analyzed by flow cytometry with a wide panel of cell membrane markers and receptors for chemokines. IFN-γ secretion was measured in vitro after PMA/Ionomycin stimulation.In comparison with CD8+HLA-DR- cells, an increased phenotype of central memory (CD45RO+CD27+CD28+,p