Agonistic anti-4-1BB antibodies enhance IgE + Ag-induced cytokine production and secretion. IgE-sensitized BMMCs were first stimulated with antigen for 6 hours, washed, and restimulated for 12 hours with different concentrations of antigen in the presence or absence of 0.5, 1, or 5 μg/mL agonistic 4-1BB mAb (clone 158321) or control rat IgG. IL-6 and TNF secreted into culture media were quantified by ELISA. ^*P < .05 (versus control antibody, Student t test). Results (mean ± SD) shown are representative of 3 similar experiments.