Transcriptomic signature of the CD24hiCD38hi transitional B cells associated with an immunoregulatory phenotype in renal transplant recipient.

The role of B cells after transplant regarding allograft rejection or tolerance has become a topic of major interest. Recently, in renal transplant recipients, a B cell signature characterized by the overexpression of CD19+CD38hiCD24hi transitional B cells has been observed in operationally tolerant patients and in Belatacept treated patients with significant lower incidence of donor specific antibodies. The phenotypic and functional characterization of these transitional B cells is far to be exhaustive. We present the first transcriptomic and phenotypic analysis associated with this phenotype. Three populations were studied and compared: (i) transitional CD24hiCD38hi (ii) CD24+CD38- and (iii) CD24intCD38int populations. Peripheral blood mononuclear cells were isolated from 5 healthy donors and CD20+ B cells were isolated by magnetic beads. Three B cells populations were then sorted by flow cytometry: CD19+CD24hiCD38hi (test), CD19+CD24+CD38- (control 1) and CD19+CD24intCD38int (control 2)