The Human (HLA-DPA1) Hla Class 2 Histocompatibility Antigen, Dp Alpha 1 Chain ELISA Kit measures Hla Class 2 Histocompatibility Antigen, Dp Alpha 1 Chain in samples. The plate has been pre-coated with Human HLA-DPA1 antibody. HLA-DPA1 present in the sample is added and binds to antibodies coated on the wells. And then biotinylated Human HLA-DPA1 Antibody is added and binds to HLA-DPA1 in the sample. Then Streptavidin-HRP is added and binds to the Biotinylated HLA- DPA1 antibody. After incubation unbound Streptavidin-HRP is washed away during a washing step. Substrate solution is then added and color develops in proportion to the amount of Human HLA-DPA1. The reaction is terminated by addition of acidic stop solution and absorbance is measured at 450 nm.
BackgroundBinds 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. Source: UniProt Consortium (2025)
Shipping ConditionShipped on cold gel packs.
Storage Condition and Shelf Life
2-8C
AnalyteHla Class 2 Histocompatibility Antigen, Dp Alpha 1 Chain
