Fig. 3

HuB6 promotes the proliferation and activation of T cells in a manner dependent on FcγR crosslinking. a The proliferation of CD8 + T cells was induced by HuB6, and the cell percentage was determined by CSFE labeling. HuB6 was used at three concentrations: 2.5, 10 and 40 μg/ml. b CD4 + T, CD8 + T and natural killer (NK) cell activation by HuB6 at the indicated concentrations was monitored through detection of INF-γ in the supernatant by ELISA. *p < 0.01 compared to the utomilumab group. c The activation of CD8 + T cells by HuB6, urelumab or utomilumab dependent on FcγR crosslinking in the presence of FcγRIA, FcγRIIA or FcγRIIB was monitored through detection of INF-γ in the supernatant by ELISA. d The activities of HuB6, urelumab and utomilumab engrafting the Fab into Fc with different subclasses (IgG2, IgG4) were compared using the functional cellular NFκB reporter assay. The results are representative of three different experiments and expressed as the mean values