| 背景 | IB17 is a monoclonal antibody directed against human CD137 (4-1BB, TNFRSF9), supplied on a fully human IgG1 framework. The human IgG1 backbone and human target reactivity make this clone well suited to studies of human T-cell costimulation, agonist-antibody characterisation, and translational immuno-oncology work where a human-format reagent is preferred over rodent surrogate antibodies. It is appropriate for in-vitro functional assays on primary human T cells and 4-1BB-expressing cell lines, receptor-binding and blocking/crosslinking studies, flow cytometry, and mechanism-of-action profiling. Because it targets a human antigen, it is intended chiefly for human-cell and ex-vivo systems rather than immunocompetent mouse models, in which it would not engage endogenous mouse 4-1BB. The antibody is offered low-endotoxin and in bulk (mg to gram) quantities to support functional and cell-based assays that are sensitive to endotoxin and require large or repeated reagent lots. All material is provided for research use only (RUO) and is not intended for diagnostic or therapeutic application.
CD137 (4-1BB, TNFRSF9) is an inducible costimulatory receptor in the TNF-receptor superfamily. It is expressed largely on activated CD4+ and CD8+ T cells, and is also found on activated NK cells, regulatory T cells, dendritic cells, and some myeloid populations. Its ligand, 4-1BBL (CD137L, TNFSF9), is presented on activated antigen-presenting cells. Engagement of CD137 delivers a TRAF-dependent signal that recruits TRAF1/TRAF2 and activates NF-kB and MAPK pathways, promoting T-cell proliferation, survival, cytokine production (notably IFN-gamma and IL-2), and enhanced effector and memory differentiation, particularly of CD8+ T cells. Because it upregulates anti-apoptotic factors and sustains effector responses, CD137 is a prominent target for agonist immunotherapy aimed at amplifying antitumour T-cell activity, and its ectodomain is a key signalling module in CD137-based chimeric antigen receptor designs. |
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