Lymphotoxin beta

Lymphotoxin-beta (LTB) is a type II membrane protein belonging to the TNF family. It forms heterotrimers with lymphotoxin-alpha, anchoring it to the cell surface. The predominant complex found on the surface of lymphocytes is the lymphotoxin-alpha 1/beta 2 complex (i.e., one molecule of alpha and two molecules of beta), which serves as the primary ligand for the lymphotoxin-beta receptor. A less common form is the lymphotoxin-alpha 2/beta 1 complex. Additionally, alternative splicing of the LTB gene results in multiple transcript variants encoding different isoforms. Notably, the lymphotoxin-beta isoform b cannot form a complex with lymphotoxin-alpha, indicating it may have functions independent of lymphotoxin-alpha. == Function ==

LTB plays a critical role in immune system regulation. It is an inducer of the inflammatory response and is essential for the normal development of lymphoid tissues. The membrane-bound lymphotoxin complexes mediate signaling through the lymphotoxin-beta receptor, influencing immune cell differentiation and tissue organization. == Clinical significance ==

The membrane-bound form of lymphotoxin has been implicated in tumorigenesis. Mice engineered to overexpress LTα or LTβ exhibit increased tumor growth and metastasis in several cancer models. However, earlier studies were limited by the use of mice lacking the entire LTα gene, making it difficult to distinguish the effects of soluble versus membrane-associated lymphotoxins. == Interactions ==

LTB has been shown to interact with Lymphotoxin alpha. == References ==