Transcriptional regulation of germinal center B and plasma cell fates by dynamical control of IRF4 (expression)

ABSTRACT: Temporal analysis of B cell activation in vitro using CD40L and IL-2/4/5 cytokines in wild type Irf4+/+ B cells or in mutant Irf4-/- B cells harboring a tet-inducible allele of Irf4. IRF4 expression was restored, or not, in the Irf4-/- background by culturing in the presence of low or high concentrations of doxycycline. The results provide insight in the role of IRF4 expression levels in coordinating different programs of B cell differentiation. Resting mature peripheral primary B cells were enriched from the spleens of Irf4+/+ or Irf4-inducible mice on the Irf4-/- background. We sought to compare gene expression profiles of wild type and Irf4 mutant B cells in response to mitogens that promote the differentiation of the B cells into plasma cells and cells that have undergone class switch recombination. Day 0 samples represent RNA analysis of unstimulated cells, whereas Day 1 and Day 3 samples represent analysis of stimulated cells in culture. For stimulation, cells were cultured with insect cell purified CD40L and IL-2/4/5 cytokines for the indicated days. In the case of doxycycline-mediated rescue of IRF4 expression, doxycycline was added at predefined low and high concentrations that yield low or high numbers of plasma cells, respectively (see Molecular Systems Biology 7:495). Each replicate represents analysis of B cells from an individual mouse. Of the three replicates in each group, two were performed in parallel and one was performed at a different time. All cells were lysed using Trizol and total RNA was purified according to manufacturer's suggestions. The high quality of the RNA was confirmed using Agilent Bioanalyzer 2100 system. 250ng of RNA was then processed into biotinylated cRNA according to standard procedures and used to hybridize to Affymetrix 430 2.0 arrays. Signal intensities were normalized using the D-Chip algorithm (PM-only model) and the output was used to quantify differential gene expression between groups.

ORGANISM(S): Mus musculus

SUBMITTER: Mark Maienschein-Cline 

PROVIDER: E-GEOD-46606 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress