Btn2a2, a T cell immunomodulatory molecule coregulated with MHC class II genes.

Evidence has recently emerged that butyrophilins, which are members of the extended B7 family of co-stimulatory molecules, have diverse functions in the immune system. We found that the human and mouse genes encoding butyrophilin-2A2 (BTN2A2) are regulated by the class II trans-activator and regulatory factor X, two transcription factors dedicated to major histocompatibility complex class II expression, suggesting a role in T cell immunity. To address this, we generated Btn2a2-deficient mice.

Rapid, sensitive and real-time multiplexing platform for the analysis of protein and nucleic-acid biomarkers.

We describe a multiplexing technology, named Evalution, based on novel digitally encoded microparticles in microfluidic channels. Quantitative multiplexing is becoming increasingly important for research and routine clinical diagnostics, but fast, easy-to-use, flexible and highly reproducible technologies are needed to leverage the advantages of multiplexing. The presented technology has been tailored to ensure (i) short assay times and high reproducibility thanks to reaction-limited binding regime, (ii) dynamic control of assay conditions and real-time binding monitoring allowing optimization of multiple parameters within a single assay run, (iii) compatibility with various immunoassay formats such as coflowing the samples and detection antibodies simultaneously and hence simplifying workflows, (iv) analyte quantification based on initial binding rates leading to increased system dynamic range and (v) high sensitivity via enhanced fluorescence collection.

The transcription factor RFX protects MHC class II genes against epigenetic silencing by DNA methylation.

Classical and nonclassical MHC class II (MHCII) genes are coregulated by the transcription factor RFX (regulatory factor X) and the transcriptional coactivator CIITA. RFX coordinates the assembly of a multiprotein "enhanceosome" complex on MHCII promoters. This enhanceosome serves as a docking site for the binding of CIITA.

Nucleosome eviction from MHC class II promoters controls positioning of the transcription start site.

Nucleosome depletion at transcription start sites (TSS) has been documented genome-wide in multiple eukaryotic organisms. However, the mechanisms that mediate this nucleosome depletion and its functional impact on transcription remain largely unknown. We have studied these issues at human MHC class II (MHCII) genes.

Identification of CIITA regulated genetic module dedicated for antigen presentation.

The class II trans-activator CIITA is a transcriptional co-activator required for the expression of Major Histocompatibility Complex (MHC) genes. Although the latter function is well established, the global target-gene specificity of CIITA had not been defined. We therefore generated a comprehensive list of its target genes by performing genome-wide scans employing four different approaches designed to identify promoters that are occupied by CIITA in two key antigen presenting cells, B cells and dendritic cells.

The dual control of TFIIB recruitment by NC2 is gene specific.

Negative co-factor 2 (NC2) is a conserved eukaryotic complex composed of two subunits, NC2alpha (Drap1) and NC2beta (Dr1) that associate through a histone-fold motif. In this work, we generated mutants of NC2, characterized target genes for these mutants and studied the assembly of NC2 and general transcription factors on target promoters. We determined that the two NC2 subunits mostly function together to be recruited to DNA and regulate gene expression.

Transcription-coupled deposition of histone modifications during MHC class II gene activation.

Posttranslational histone modifications associated with actively expressed genes are generally believed to be introduced primarily by histone-modifying enzymes that are recruited by transcription factors or their associated co-activators. We have performed a comprehensive spatial and temporal analyses of the histone modifications that are deposited upon activation of the MHC class II gene HLA-DRA by the co-activator CIITA. We find that transcription-associated histone modifications are introduced during two sequential phases.

Expression of RAB4B, a protein governing endocytic recycling, is co-regulated with MHC class II genes.

The small GTPase RAB4 regulates endocytic recycling, a process that contributes to Major Histocompatibility Complex (MHC)-mediated antigen presentation by specialized antigen presenting cells (APC) of the immune system. The gene encoding the RAB4B isoform of RAB4 was singled out by two complementary genome-wide screens. One of these consisted of a computer scan to identify genes containing characteristic MHC class II-related regulatory sequences.