Mouse Lymphotoxin-alpha /TNF-beta Alexa Fluor® 647-conjugated Antibody

Tumor necrosis factor-beta (TNF-beta), also known as lymphotoxin-alpha (LT-alpha), is a secreted homotrimeric glycoprotein belonging to the TNF superfamily and is designated TNFSF1B. It is produced by NK, T, and B cells. TNF-beta was originally identified as protein that kills tumor cells in cell culture supernatants of a lymphoblastoid cell line. The TNF-beta subunit also associates with the type II transmembrane TNF superfamily protein lymphotoxin beta (LT beta) to generate two types of heterotrimers designated as LT alpha1 beta2 (a single TNF-beta chain non-covalently associated with two chains of LT beta), and LT alpha2 beta1 (1, 2). TNF-alpha, TNF-beta, and LT beta form a subfamily of the TNF related ligands. Their genes are genetically linked within a compact cluster inside the major histocompatibility complex locus (2, 3). The soluble TNF-beta binds and signals through TNF R1 and TNF R2. In contrast, the membrane-bound LT alpha1 beta2 interacts specifically with the LT beta receptor (LT betaR), which does not bind TNF-beta or TNF-alpha. Both TNFR1 and TNFR2 bind LT alpha2 beta1, which is recognized weakly by LT beta R (4, 5). TNF R1 and 2 express very broadly, while expression of LT beta R is restricted to stromal cells of lymphoid tissues. Herpesvirus entry mediator binds TNF-beta in vitro (6). The physiological importance of such interaction, if it occurs in vivo, is unclear. Distinct functions attributed to TNF-beta from transgenic knock-out mice include, loss of lymph node development, change in splenic architecture, impaired germinal center formation, and susceptibility to pulmonary tuberculosis (7, 8). TNF-beta also has overlapping physiological functions with LT beta and TNF-alpha in lymphoid organogenesis (7). Mouse and human TNF-beta share approximately 74% homology in their amino acid sequence.