About RecombiMAb anti-mouse 4-1BB (CD137) (LALA-PG) The LOB12.3-CP038 monoclonal antibody is a chimeric version of the original LOB12.3 antibody. The variable domain sequences are identical to the original LOB12.3 but the constant region sequences have been switched from rat IgG1 to mouse IgG2a. The LOB12.3-CP038 antibody also contains a LALA-PG mutation in the Fc fragment rendering it unable to bind to endogenous Fcγ receptors. The LOB12.3-CP038 antibody reacts with mouse 4-1BB, a TNF receptor superfamily member also known as CD137. 4-1BB is a 39 kDa transmembrane protein expressed by T lymphocytes, NK cells, dendritic cells, granulocytes, and mast cells. Upon binding its ligand 4-1BBL, 4-1BB provides costimulatory signals to both CD4 and CD8 T cells through the activation of NF- κB, c-Jun and p38 downstream pathways. The importance of the 4-1BB pathway has been underscored in a number of diseases, including cancer. Agonistic anti-4-1BB antibodies have been reported to induce T cell mediated antitumor immunity. The LOB12.3 antibody is an agonistic antibody that has been shown to stimulate 4-1BB signaling and delay tumor growth in vivo when administered in combination with immune checkpoint inhibitors. RecombiMAb anti-mouse 4-1BB (CD137) (LALA-PG) Specifications IsotypeMouse IgG2a, κ Recommended Isotype Control(s)RecombiMAb mouse IgG2a (LALA-PG) isotype control, anti-hen egg lysozyme Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenMouse CD137 human Fc fusion protein Reported Applicationsin vivo activation of 4-1BB* *Reported for the original rat IgG1 LOB12.3 antibody FormulationPBS, pH 7.0 Contains no stabilizers or preservatives Endotoxin<1EU/mg (<0.001EU/μg) Determined by LAL gel clotting assay Aggregation<5% Determined by SEC Purity>95% Determined by SDS-PAGE Sterility0.2 μm filtration ProductionPurified from HEK293 cell supernatant in an animal-free facility PurificationProtein G Molecular Weight150 kDa StorageThe antibody solution should be stored at the stock concentration at 4°C. Do not freeze.