MHC Class I, H-2K Antibody

Major Histocompatibility Complex (MHC) molecules are essential components of the immune system, playing a crucial role in antigen presentation and immune response. In mice, the MHC class I molecules are encoded by the H-2 complex, which is located on chromosome 17. The H-2K molecule is one of the classical MHC class I molecules in mice, and it is involved in presenting endogenous antigens to CD8+ T cells.

MHC class I molecules are composed of a highly glycosylated 45 kDa alpha chain and a 12 kDa beta-2 microglobulin (β2-MG) chain. The alpha chain is a transmembrane glycoprotein encoded by polymorphic genes located in the H-2 complex. The alpha chain consists of three extracellular domains (α1, α2, and α3), a transmembrane domain, and a cytoplasmic tail. The β2-MG chain is non-covalently associated with the alpha chain and is encoded by a separate gene .

MHC class I molecules are expressed on the surface of almost all nucleated cells. Their primary function is to present peptide antigens derived from intracellular proteins to CD8+ cytotoxic T lymphocytes (CTLs). This process is crucial for the immune system to recognize and eliminate infected or malignant cells. The peptides presented by MHC class I molecules are typically 8-10 amino acids long and are generated by the proteasome in the cytoplasm. These peptides are then transported into the endoplasmic reticulum (ER) by the transporter associated with antigen processing (TAP) and loaded onto MHC class I molecules .

The H-2K molecule is one of the classical MHC class I molecules in mice, along with H-2D and H-2L. These molecules are highly polymorphic, meaning they have multiple alleles that encode different versions of the molecule. This polymorphism is essential for the immune system to recognize a wide variety of antigens. The H-2K molecule is involved in presenting endogenous antigens to CD8+ T cells, which is critical for the immune response against intracellular pathogens and tumors .

The expression of MHC class I molecules is regulated by various cytokines and transcription factors. Interferons (IFNs) such as IFN-α, IFN-β, and IFN-γ can upregulate the expression of MHC class I molecules. IFN-γ, in particular, induces the formation of a specific transcription factor that binds to the promoter region of MHC class I genes, enhancing their transcription. Additionally, tumor necrosis factor (TNF) can also increase the expression of MHC class I molecules .

Antibodies against H-2K molecules are widely used in immunological research. These antibodies can be used to study the expression and function of MHC class I molecules in various cell types and tissues. They are also used in flow cytometry, immunohistochemistry, and other immunoassays to detect and quantify MHC class I molecules on the cell surface. Furthermore, H-2K antibodies can be used to investigate the role of MHC class I molecules in immune responses, including their involvement in antigen presentation, T cell activation, and immune surveillance .