MHC Class II Transactivator Is an In Vivo Regulator of Osteoclast Differentiation and Bone Homeostasis Co-opted From Adaptive Immunity

Deregulated MHC Class II Transactivator

MHC class II enhanceosome: how is the class II transactivator recruited to DNA-bound activators?

MHC class II (MHCII) determinants play a crucial role in the immune response by presenting antigenic peptides to T cells. Their expression is controlled from compact promoters at the transcriptional level. Pre-assembled regulatory factor X (RFX) and nuclear factor Y (NFY) complexes form a platform on DNA. The class II transactivator (CIITA) can then be recruited through multiple protein-protein...

An Isotype-specific Activator of Major Histocompatibility Complex (MHC) Class II Genes That Is Independent of Class II Transactivator

Patients with one type of major histocompatibility complex class II combined immunodeficiency have mutations in a gene termed class II transactivator (CIITA), which coordinately controls the transcription of the three major human class II genes, HLA-DR, -DQ, and -DP. However, the experimentally derived B-lymphoblastoid cell line, clone 13, expresses high levels of HLADQ in the absence of HLA-DR...

Class II Transactivator Modulation of Gene Expression by the MHC

The Smad3 protein is involved in TGF-beta inhibition of class II transactivator and class II MHC expression.

TGF-beta is a immunoregulatory cytokine that inhibits class II MHC expression in a variety of cell types. Previous studies have shown that the class II MHC transactivator (CIITA), a master regulator that controls class II MHC expression, is targeted by TGF-beta for repression of IFN-gamma-induced class II MHC expression in astrocytes. The mechanism(s) underlying the TGF-beta inhibitory effect i...