IL6R-α neutralization with tocilizumab does not impair the phenotypic maturation of moDCs or alloreactive T-cell proliferation. (A-D) DCs were matured for 48 hours with LPS, in the presence of tocilizumab or control Ig, both at 5ug/mL final. Representative histograms depict selected markers of DC maturation. Bar graphs show the averaged MFI (mean fluorescent intensity) from 4 independent experiments, ± SD; NS = not significant, paired t test. (E) Bar graphs show means from 4 independent experiments, ± SD, evaluating inhibition of IL6-induced pSTAT3 by tocilizumab in immature moDCs (HLA-DR⁺, top) and resting T cells (CD3⁺, bottom); *P < .05, paired t test. (F) A fixed number of T cells was cultured with variable doses of allogeneic DCs at DC:T ratios from 1:30 to 1:1000. Tocilizumab or control Ig (5ug/mL) was added once on d0. AlloMLRs were cultured for 5 days at 37°C. T-cell proliferation was assessed using a colorimetric assay. Graph shows the average of triplicate means from 4 independent experiments, ± SEM; NS = not significant, paired t test of area under the curve (AUC).