Identification of differentially expressed genes between control and PIK3CD GOF human activated transitional B cells

IL-21 induces B cell activation, and differentiation into antibody-secreting plasmblasts in vitro. This process is compromised in transitional B cells to gain of function mutations in PIK3CD We used microarrays to identify genes that are differentiatlly expressed following CD40L/IL-21 stimulation of human transitonal B cells from healthy donors and patients with GOF mutations in PIK3CD Sort-purified transitional B cells from 3 healthy donors and 3 patients with APDS due to heterozygous activating gain of function PIK3CD mutations were cultured for four days with CD40L +/- IL-21 (50ng/ml). RNA was then extracted from the harvested cells and the genetic profile analysed by microarray.