Project description:Mouse splenic dendritic cells are divided into different subsets based on their phynotype. CD8α+ and CD8α- dendritic cells play different roles against pathogens. Cross-presentation is essential for immune defense against viruses, tumors and intracellular bacteria and CD8α+ DCs are more potent in cross-presentation compared to CD8α- DCs. We used microarrays to detail the global gene expression to analyze the underlying mechanism in CD8α+ dendritic cells cross-presentation Splenic CD8α+ and CD8α- dendritic cells were sorted by flow-cytometer for RNA extraction and hybridization on Affymetrix microarrays. Thirty C57BL/6J mice were sacrified for the splenic cells, splenic DCs were enriched by negtive selection, then CD8α+ and CD8α- dendritic cells were seprated based on CD11c and CD8α markers.
Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.