BDCA2-ADC suppresses IFNα and proinflammatory cytokine secretion from TLR-activated PBMCs. PBMCs from three healthy donors were pretreated with 300 nM BIIB059 or BDCA2-ADC and then stimulated with 2.5 μM CpG-A or 5 μM R848 for 24 h. The secretion of IFNα, TNFα, IL-6 and IL-8 was measured by ELISA. ADC: antibody–drug conjugate; BDCA2: blood dendritic cell antigen 2; PBMC: peripheral blood mononuclear cell; TLR: toll-like receptor