Figure 3.

IL-21 production by remaining activated follicular T-helper (Tfh) cells was not inhibited by belatacept in vitro. A typical example is depicted for the intracellular IL-21 production after donor antigen stimulation in non-activated and activated Tfh-cells (CXCR5⁺PD-1⁻ and CXCR5⁺PD-1⁺ CD4⁺ T-cells, respectively) in the presence and absence of belatacept (A). The proportions of IL-21⁺ cells within non-activated and activated Tfh-cells were compared after 7 days of donor antigen stimulation of peripheral blood mononuclear cells (PBMCs) obtained from both belatacept- and tacrolimus-treated patients (B). The proportions of IL21⁺-activated Tfh-cells within CD4⁺ T-cells (C) and the proportions of IL-21⁺ cells within activated Tfh-cells (D) were compared between 7-day donor antigen-stimulated PBMCs obtained from the belatacept and tacrolimus group (“in vivo” column), as well as the relative inhibitions by in vitro addition of belatacept or tacrolimus (“additional in vitro” column). In the graphs in the “In vivo drug” columns, every dot represents PBMCs of a single patient. In the graphs in the “additional in vitro drug” columns, the relative inhibitions by additional in vitro belatacept and tacrolimus are depicted for aforementioned cell populations in the same belatacept- and tacrolimus-treated patients. The proportions of these cell populations after donor antigen stimulation in the absence of in vitro drugs are set to 0. The median relative inhibitions by belatacept and tacrolimus were tested against a theoretical median of 0. Asterisks below the boxes depict the p-values of these tests. The relative inhibitions were compared between belatacept and tacrolimus in vitro. Lines in boxes represent medians, borders of boxes represent 25th and 75th percentiles, error bars present 10th and 90th percentiles. Every box represents cultures of PBMCs obtained from n = 20 belatacept-treated or n = 20 tacrolimus-treated patients. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, NS, not significant.