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.
Applications:Suitable for use in ELISA, Western Blot and Immunohistochemistry.
Other applications not tested.
Recommended Dilution:Western Blot: 1:1000Immunohistochemistry (Paraffin): 1:25Optimal dilutions to be determined by the researcher.
Storage and Stability:May be stored at 4°C for short-term only.
Aliquot to avoid repeated freezing and thawing.
Store at -20°C.
Aliquots are stable for 12 months after receipt.
For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
仕様
Size：200ul
Host：rabbit
Source Antibody：human
Grade：Affinity Purified
Purity：Purified by Protein A and peptide affinity chromatography.
Form：Supplied as a liquid in PBS, 0.09% sodium azide.
Specificity：Recognizes human HLA-DRB1.
Isotype：IgG
Calc Applications Abbrev：E IHC WB
Calc Crossreactivity：Hu
Immunogen：KLH-conjugated synthetic peptide mapping to a fragment of residues within amino acids 103-137 of the Central region of human HLA-DRB1.
