Monoclonal antibody clone Tx83 recognizes mouse allergy inhibitory receptor-1 (Allergin-1; also known as mast cell antigen AG-32). It is an immune regulatory molecule predominantly expressed on mast cells, but also found on other myeloid cells like macrophages, dendritic cells and neutrophils. The receptor consist of an immunoreceptor tyrosine-based inhibitory motif (ITIM) like domain. It’s main function is to suppress IgE (FcεRI-) mediated degradation and TLR2- mediated signaling in mast cells. Thereby inhibiting production of cytokines and other inflammatory mediators. Allergin-1 is tyrosine phosphorylated and recruits SH2 phosphatases , such as SHP-1, SHP-2 or SHIP. Co-ligation with FcεRI decreases mast cell degranulation. Currently three isoforms of human allergin-1 are identified: allergin-1L, Allergin-1S1 & allergin-1S2.
Mast cells play a pivotal role in allergic reactions in barrier tissues, like skin and intestinal mucosa. Allergin-1 is suggested to play a role in skin diseases like dermatitis, the autoimmune diseases such as SLE and airway hyperresponsiveness. In macrophages it is suggested to play a role by suppressing autoantibody production via the promotion of apoptotic cell clearance.