Expression in wild type and TgDREAM mouse B cells unstimulated or 2 days after LPS+IL4 stimulation

DREAM/KChIP-3 is a calcium-dependent transcriptional repressor highly expressed in immune cells. Transgenic mice expressing a dominant active DREAM mutant show reduced serum immunoglobulin levels. In vitro assays show that reduced immunoglobulin secretion is an intrinsic defect of transgenic B cells that occurs without impairment in plasma cell differentiation but with an accelerated entry in cell division and an increase in class switch recombination. B cells from DREAM knockout mice did not show any phenotype, due to compensation by endogenous KChIP-2. Expression arrays revealed modified expression of Edem1 and Derlin3, two proteins related to the ER-associated degradation pathway and of Klf9, a cell-cycle regulator. Our results disclose a function of DREAM and KChIP-2 in Ig subclass production in B lymphocytes. We used Affymetrix microarrays (GeneChip Mouse Genome 430 2.0) to compare global gene expression in wild type (WT) versus transgenic B cells (Tg), unstimulated and 2 days after LPS + IL4 stimulation. For ech type of sample three hybridizations were carried-out (independent biological replicates).