CD31+ T Cells Represent a Functionally Distinct Vascular T Cell Phenotype

Abstract

CD3+/CD31+ T cells aid in endothelial repair and revascularization. In contrast, CD3+/CD31‐ cells show no vascular effects. There is limited data regarding the functional differences between circulating CD3+/CD31+ and CD3+/CD31‐ cells that may contribute to their divergent cardiovascular effects. The aim of the present study was to characterize functional differences between CD3+/CD31+ and CD3+/CD31‐ cells. To address this aim, migratory capacity, proangiogenic cytokine release and apoptotic tendency of CD31+ and CD31‐ T cells were determined. Human CD31+ and CD31‐ T cells from peripheral blood were isolated using magnetic‐activated cell sorting. CD31+ T cells demonstrated higher (~60%, P<0.01) migratory capacity to the chemokines VEGF (618±99 vs 259±57) and SDF‐1 (655±99 vs 273±54) vs CD31‐ cells. Release of angiogenic cytokines VEGF, interleukin‐8, and matrix metalloprotease‐9 were also ~100% higher (P<0.05) in CD31+ T cells. CD31+ cells exhibited significantly higher intracellular concentrations of active caspase‐3 (2.61±0.60 vs 0.34±0.09 ng/ml) and cytochrome‐c (21.8± 1.4 vs 13.7±0.96 ng/mL). In summary, CD31+ T cells have greater migratory and angiogenic cytokine release capacity but are more susceptible to apoptosis compared with CD31‐ T cells. Enhanced migratory capacity and angiogenic cytokine release may contribute to the vasculogenic properties of this unique T cell subpopulation.