CD74 Monoclonal Antibody (VIC-Y1), eBioscience™, Invitrogen™

Description

Description: This VIC-Y1 monoclonal antibody recognizes human CD74, also known as the MHC Class II-associated invariant chain. A 33-43 kDa nonpolymorphic type II membrane protein, CD74 is highly expressed on B cells and subsets of activated T cells, Langerhans cells, dendritic cells, and epithelial cells. Monocytes and macrophages also express CD74, but at lower levels. CD74 acts as a chaperone of MHC Class II (HLA-DR) proteins, promoting their translocation from the ER to endocytic compartments during antigen presentation. Activation of NFkB and ERK has been shown following CD74 interaction with CD44 and binding to the proinflammatory cytokine macrophage migration-inhibitory factor (MIF). CD74 also plays a role in the maturation of follicular B-cells and accumulation of marginal zone B-cells. CD74 has also been demonstrated to interact with CXCR2 and CXCR4. The VIC-Y1 monoclonal antibody binds to a cytoplasmic region of human CD74 and thus cannot be used to detect cell surface expression of this molecule. Applications Reported: This VIC-Y1 antibody has been reported for use in immunohistochemical staining of formalin-fixed paraffin embedded tissue sections. Applications Tested: This VIC-Y1 antibody has been tested by immunohistochemistry on formalin-fixed paraffin embedded human tonsil tissue using low pH antigen retrieval. This antibody can be used at less than or equal to 5 μg/mL.

HLA-DR, like other MHC class II molecules, is a transmembrane glycoprotein composed of a 36 kDa alpha chain (DRA) and 27 kDa beta chain (DRB). The alpha chain gene contains 5 exons. Exon 1 encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, and exon 4 encodes the transmembrane domain and the cytoplasmic tail. DRA does not have polymorphisms in the peptide binding part and acts as the sole alpha chain for DRB1, DRB3, DRB4 and DRB5. Within the DR molecule the beta chain contains all the polymorphisms specifying the peptide binding specificities. Hundreds of DRB1 alleles have been described and typing for these polymorphisms is routinely done for bone marrow and kidney transplantation. HLA-DR is expressed primarily on antigen presenting cells such as B lymphocytes, monocytes, macrophages, thymic epithelial cells and activated T lymphocytes. Three loci, DR, DQ and DP, encode the major expressed products of the human class II region. The human MHC class II molecules bind intracellularly processed peptides, present them to T-helper cells, and have a critical role in the initiation of the immune response.