Description
Product Usage Information
Immunohistochemistry (Paraffin): 1:100 - 1:400
Storage
Supplied in PBS (pH 7.2), less than 0.1% sodium azide, and 2 mg/mL BSA. Store at 4°C. Do not aliquot the antibody. Protect from light. Do not freeze.
Protocol
Available protocols: Immunohistochemistry (Paraffin)
Specificity / Sensitivity
CD74 (F3R3L) Rabbit Monoclonal Antibody (Alexa Fluor
Species Reactivity: Mouse
Source / Purification
Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Pro138 of mouse CD74 protein.
Background
CD74, which is also known as the MHC Class II-associated invariant chain (Ii), is a type II transmembrane glycoprotein that plays a critical role in the antigen presentation process as a chaperone of MHC Class II proteins. It is expressed at high levels on B cells and to a lesser extent on numerous antigen presenting cell (APC) types including dendritic cells, Langerhans cells, monocytes, and macrophages as well as non-traditional APCs such as epithelial cells (1,2). CD74 was initially identified for its ability to regulate the folding and intracellular trafficking of newly synthesized MHC Class II molecules. Following expression, CD74 self-assembles as a trimer that serves as a scaffold for the assembly of MHC Class II molecules. Through this interaction, CD74 blocks the peptide binding cleft of MHC Class II molecules and prevents their premature association with endogenous polypeptides (3). Binding to CD74 also facilitates the translocation of MHC Class II molecules from the endoplasmic reticulum to the endocytic compartments during antigen presentation (4). In addition to its role as an MHC Class II chaperone, CD74 is also the receptor for macrophage migration-inhibitory factor (MIF). Binding to CD74 and its co-receptor, CD44, has been shown to induce the activation of the NFkB and ERK pathways to promote cell proliferation and survival signals (5,6). Recent studies have identified CXCR2 and CXCR4 as co-receptors for CD74 where MIF binding to CD74 complexes contributes to MIF-mediated monocyte chemotaxis and the induction of Akt signaling, respectively (7,8). Increased CD74 surface expression has been reported under inflammatory conditions and in certain types of cancer cells implying a potential role in tumorigenesis (9).
Alternate Names
Cd74; CD74 antigen (invariant polypeptide of major histocompatibility complex, class II antigen-associated); class II-associated invariant chain peptide; Class-II-associated invariant chain peptide; CLIP; DHLAG; dinucleotide microsatellite; H-2 class II histocompatibility antigen gamma chain; HG2A; histocompatibility: class II antigens, gamma chain of; HLA-DR-GAMMA; HLADG; Ia antigen-associated invariant chain; Ia-associated invariant chain; Ia-GAMMA; invariant polypeptide of major histocompatibility complex, class II antigen-associated; MHC class II-associated invariant chain
