Human 4-BBL or TNFSF9 is a member of the TNF superfamily. It is a type 2 transmembrane protein expressed on activated T-cells. It is a bidirectional signal transducer which acts as a costimulatory receptor molecule on T lymphocytes. Its functions primarily stimulate the immune response by promoting the release of cytokines such as IL-2 and IFN-gamma. TNFSF9 works with TNFRSF9 for the generation of cytotoxic T cells, proliferation of T-cells as well as antigen presentation. It also reactivates T lymphocytes which have become anergic. It is also expressed on activated NK cells, B-cells, macrophages, dendritic cells and some brain cells. Recombinant Human 4-BBL is a 19.6 kDa protein.
>95% as determined by SDS-PAGE
<1.0 EU/μg of recombinant protein as determined by the LAL method
The lyophilized protein is stable for at least one year from date of receipt at -70?C. Upon reconstitution, this cytokine can be stored in working aliquots at 2? - 8?C for one month, or at -20?C for six months, with a carrier protein without detectable loss of activity.
Avoid repeated freeze/thaw cycles.