An alpha chain of antigen-presenting major histocompatibility complex class II (MHCII) molecule. In complex with the beta chain HLA-DRB, displays antigenic peptides on professional antigen presenting cells (APCs) for recognition by alpha-beta T cell receptor (TCR) on HLA-DR-restricted CD4-positive T cells. This guides antigen-specific T-helper effector functions, both antibody-mediated immune response and macrophage activation, to ultimately eliminate the infectious agents and transformed cells . Typically presents extracellular peptide antigens of 10 to 30 amino acids that arise from proteolysis of endocytosed antigens in lysosomes . In the tumor microenvironment, presents antigenic peptides that are primarily generated in tumor-resident APCs likely via phagocytosis of apoptotic tumor cells or macropinocytosis of secreted tumor proteins . Presents peptides derived from intracellular proteins that are trapped in autolysosomes after macroautophagy, a mechanism especially relevant for T cell selection in the thymus and central immune tolerance . The selection of the immunodominant epitopes follows two processing modes: ''bind first, cut/trim later'' for pathogen-derived antigenic peptides and ''cut first, bind later'' for autoantigens/self-peptides . The anchor residue at position 1 of the peptide N-terminus, usually a large hydrophobic residue, is essential for high affinity interaction with MHCII molecules . .

P01903

HLA class II histocompatibility antigen, DR alpha chain (MHC class II antigen DRA),HLA-DRA HLA-DRA1,HLA-DRA1, MHC class II antigen DRA, HLA-DRA, HLA class II histocompatibility antigen, DR alpha chain

Human

FC

FC 1:50-1:200

29kD

PE

Mouse

Monoclonal

DC339

IgG1, kappa

0.01M PBS, pH 7.4, 0.2% BSA, 0.05% Proclin 300.

0.5 mg/ml

Store at 4℃ for 12 months. Protect from light. Do not freeze.