Expression of inhibitory receptors on CD4+ and CD8+ T cells from healthy Colombian donors

T cell activation involves positive cellular signals that promote effector functions and negative signals that contribute to the regulationof these responses. These regulatory signals are generated upon activation of receptors on T cells that include CD160, 2B4, ProgrammedDeath-1 and CTLA-4. Objective. To evaluate the expression of inhibitory receptors like CD160, 2B4, Programmed Death-1 and CTLA-4 on CD4+ and CD8+ T cells from healthy Colombian donors. Materials and methods. Peripheral blood mononuclear cells from 30healthy donors from Bogotá (Colombia) were obtained via Ficoll-Hypaque density gradient and cells were stained with specific conjugatedantibodies previously titrated. Results. The CD160, 2B4, and Programmed Death-1 inhibitory markers were detected on CD4+ T cellswith expression levels of 0.35%, 1.04%, and 1.35%, respectively. On CD8+ T cells, these markers were expressed at higher levels: 16%,8.97%, and 4.3%, respectively. In contrast to the other receptors, CTLA-4 frequency of expression showed no significant differencebetween CD4+ (1.56%) and CD8+ (1.53%) T cells. Frequency of CD160/2B4 and CTLA-4/ Programmed Death-1 coexpression was0.18% and 0.09% on CD4+ cells, and 4.02% and 0.2% on CD8+ T cells. Conclusions. This is the first report showing the frequencyof inhibitory receptors such as CD160, 2B4, Programmed Death-1, and CTLA-4 on CD4+ and CD8+ T cells from healthy Colombiandonors. Our findings serve as a baseline for the analysis and comparison of these receptors in Colombian populations with differentdisease conditions.