Exploring genome-wide datasets of MHC class II antigen presentation.

MHC class II molecules (MHCII) are critical for presenting antigens to CD4(+) T-cells. They control ignition of CD4(+) T cells and are as such involved in most auto-immune diseases. To define proteins and pathways controlling MHCII antigen presentation and expression, we performed a genome-wide flow cytometry based RNAi screen. Hits were subsequently classified by two screens that monitored the intracellular distribution and transcription of MHCII. This multi-dimensional approach allowed subclassification of hits into functional groups as a first step to defining new pathways controlling MHCII antigen presentation. The datasets from this screen are used as a template for several follow-up studies. This overview focuses on how data from genome-wide screens can be used for target-lead finding, data mining, systems biology and systematic cell biology.