|Application ||WB, IHC|
|Calculated MW||28607 Da|
|Other Names||HLA class II histocompatibility antigen, DR alpha chain, MHC class II antigen DRA, HLA-DRA, HLA-DRA1|
|Target/Specificity||A synthetic peptide corresponding to residues in human HLA-Dra was used as an immunogen.|
|Format||50 mM Tris-Glycine (pH 7.4), 0.15 M NaCl, 40% Glycerol, 0.01% sodium azide and 0.05% BSA.|
|Storage||Maintain refrigerated at 2-8°C for up to 6 months. For long term storage store at -20°C in small aliquots to prevent freeze-thaw cycles.|
|Precautions||HLA-Dra Antibody is for research use only and not for use in diagnostic or therapeutic procedures.|
|Function||Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal microenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.|
|Cellular Location||Cell membrane; Single-pass type I membrane protein. Endoplasmic reticulum membrane; Single-pass type I membrane protein. Golgi apparatus, trans-Golgi network membrane; Single-pass type I membrane protein. Endosome membrane; Single- pass type I membrane protein. Lysosome membrane; Single-pass type I membrane protein. Late endosome membrane; Single-pass type I membrane protein. Note=The MHC class II complex transits through a number of intracellular compartments in the endocytic pathway until it reaches the cell membrane for antigen presentation|
Thousands of laboratories across the world have published research that depended on the performance of antibodies from Abgent to advance their research. Check out links to articles that cite our products in major peer-reviewed journals, organized by research category.
firstname.lastname@example.org, and receive a free "I Love Antibodies" mug.
Provided below are standard protocols that you may find useful for product applications.
Human class II major histocompatibility complex (MHC) products are essential initiators of cellular immune responses. Their cell surface expression demonstrates aspects of tissue-restriction, inducibility, differentiation-dependence, and coordinate regulation indicative of complex molecular controls mediated primarily at the level of transcription (1). There are three major isotypes of human class II MHC molecules; HLA-DR, HLA-DP, and HLA-DQ, each of which consists of an alpha and beta chain (2). HLA-DR alpha is a polymorphic cell surface glycoprotein that is crucial for the cellular interaction in immune response. Class II molecules have limited tissue distribution and are predominantly expressed on B lymphocytes and macrophage and present peptides derived from extracellular proteins to T cells (3).
1. Cogswell JP, et al. Crit Rev Immunol. 11(2):97-112, 1991 2. Hasegawa SL, et al. Nucleic Acids Res. 19(22):6269-76, 1991 3. Hriday et al., Biochemistry 1983; 80:3543-3547.
If you have used an Abgent product and would like to share how it has performed, please click on the "Submit Review" button and provide the requested information. Our staff will examine and post your review and contact you if needed.
If you have any additional inquiries please email technical services at email@example.com.