About RecombiMAb anti-mouse ICOSL (CD275) (LALA-PG) The HK5.3-CP046 monoclonal antibody is a chimeric version of the original HK5.3 antibody. The variable domain sequences are identical to the original HK5.3 but the constant region sequences have been switched from rat IgG2a to mouse IgG2a. The HK5.3-CP046 antibody also contains a LALA-PG mutation in the Fc fragment rendering it unable to bind to endogenous Fcγ receptors. The HK5.3-CP046 monoclonal antibody reacts with mouse ICOSL (inducible T cell co-stimulator ligand) also known as CD275, B7RP-1, and B7-H2. ICOSL is a 40 kDa immune checkpoint protein belonging to the Ig receptor superfamily. Upon ICOSL binding, ICOS signaling co-stimulates T and B cell responses. The ligand Is expressed on antigen presenting cells including splenic B cells, dendritic cells, and macrophages. ICOS signaling is also thought to be important for maintaining regulatory T cell homeostasis. The HK5.3 antibody has been shown to block the binding of ICOSL to ICOS both in vitro and in vivo. HK5.3 treatment of mice has been reported to lead to a loss of regulatory T cells. RecombiMAb anti-mouse ICOSL (CD275) (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 B7-RP1 transfected cell line Reported Applicationsin vivo ICOSL neutralization* *Reported for the original rat IgG2a HK5.3 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.