Anti-Mouse/Rat CD278 (ICOS) Purified

Description: The C398.4A monoclonal antibody reacts with ICOS (Inducible Costimulatory molecule), also known as H4/CRP-1/AILIM, and cross-reacts with mouse and rat ICOS. ICOS is a T cell specific activation molecule and a third member of the CD28/CTLA-4 family. A dimer of 47-57 kDa, ICOS is expressed on activated T cells, has potent costimulatory activity for T cell activation and proliferation and is required for humoral immune response. ICOS binds to its ligand on activated APC including B cells called B7h/B7RP-1, is thought to play a protective role in inflammatory autoimmune diseases and be involved in the development of Th2 cells. C398.4A is reported to display strong costimulation of proliferation of T cell clones, intermediate costimulation on activated T cells, and weak costimulation on fresh resting T cells. It is a good costimulator of IL-10 production especially from pre-activated cells that express high level of H4/ICOS. The epitope recognized by C398.4A is different from that bound by the ICOSL (i.e., C398.4A does not block binding of ICOSL).

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