Claudin 18.2/CD3 Antibodies

Target Information

The Claudin 18.2 gene is a member of the claudin family and has an integral role in tight junctions, which are critical for maintaining cell polarity and the barrier function of epithelial cells. It is located on the long arm of chromosome 3 at position 24.1 (3q24.1). The protein encoded by this gene is involved in mediating and regulating paracellular transport and contributing to the selective permeability of cellular barriers. Claudin 18.2 is known for its specific expression in gastric epithelial cells and is upregulated in certain cancers, making it a promising target for immunotherapy.

The CD3 complex, composed of gamma, delta, epsilon, and zeta subunits, is essential for the assembly, trafficking, and surface expression of the T cell receptor (TCR) complex. These subunits are structurally related members of the immunoglobulin superfamily and are encoded by closely linked genes on human chromosome 11. CD3 is expressed by thymocytes in a developmentally regulated manner and by all mature T cells, but not on B or NK cells. The CD3 subunits play a crucial role in transducing antigen-recognition signals into the cytoplasm of T cells. The cytoplasmic tails of CD3 subunits contain a double tyrosine-based motif that associates with cytoplasmic signal transduction molecules, mediating T cell activation through the TCR. Crosslinking of the TCR initiates intracellular biochemical pathways that result in cellular activation, proliferation, and potentially growth arrest and cell survival. CD3 is present on 68-82% of normal peripheral blood lymphocytes, 65-85% of thymocytes, and Purkinje cells in the cerebellum. Decreased percentages of T lymphocytes may be observed in some autoimmune diseases. Defects in the CD3 gene are associated with CD3 immunodeficiency, highlighting its importance in immune function and regulation.