CD40LG : CD40 ligand
Description
The CD40LG (CD40 ligand) is a protein-coding gene located on chromosome X.
The CD40LG gene provides instructions for making a protein called CD40 ligand, which is found on the surface of immune system cells known as T cells. CD40 ligand attaches like a key in a lock to its receptor protein, CD40, which is located on the surface of immune system cells known as B cells. B cells are involved in the production of proteins called antibodies or immunoglobulins that help protect the body against infection. There are several classes of antibodies, and each one has a different function in the immune system. B cells are able to mature into the cells that produce immunoglobulin M (IgM) without any signals from other cells. In order for B cells to mature into the cells that produce antibodies of a different class, the CD40 receptor must interact with CD40 ligand. When these two proteins are connected, they trigger a series of chemical signals that instruct the B cell to start making immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin E (IgE).CD40 ligand is also necessary for T cells to interact with other cells of the immune system, and it plays a key role in T cell differentiation (the process by which cells mature to carry out specific functions).
CD40LG is a cytokine that acts as a ligand to CD40/TNFRSF5. It costimulates T-cell proliferation and cytokine production. Cross-linking of CD40LG on T-cells generates a costimulatory signal that enhances the production of IL4 and IL10. CD40LG induces the activation of NF-kappa-B, MAPK8 and PAK2 kinases in T-cells. It also induces tyrosine phosphorylation of CD28 isoform 3. CD40LG mediates B-cell proliferation in the absence of co-stimulus and IgE production in the presence of IL4. It is involved in immunoglobulin class switching.
CD40LG is also known as CD154, CD40L, HIGM1, IGM, IMD3, T-BAM, TNFSF5, TRAP, gp39, hCD40L.
