Distribution of CD31 on CD4 T-Cells from Cord Blood, Peripheral Blood and Tonsil at Different Stages of Differentiation

CD31+ is a marker for recent thymic emigrants. Nevertheless it is present in a proportion of memory cells. We looked at the distribution of CD31 on CD4 T-cell subpopulations. In cord blood, CD31 was present in the majority of the CD45RA high and 60% of the CD45RA low cells, and in adults over 70% of “true” naïve and in 5–10% of all memory subpopulations (central memory, effector memory, follicular helper and T regulatory cells). No major differences were seen in the distribution of chemokine receptors between CD31+ and CD31– populations within the naïve cells nor the memory populations except for CCR3 and CCR9, which were preferentially expressed in the CD31+ memory cells. The CD31 distribution and cytokine receptors was similar between HIV negative and positive individuals, and between adult blood and tonsils. There was a correlation between the levels of TRECs and the percentages of CD31 in all samples studied.