Transient pDC depletion has an immediate effect on the presence of circulating autoantibodies. Male DTR⁺ and DTR^– mice were treated with DT and analyzed at 11 wk of age. Untreated, healthy female littermates are shown. (A–C) Total IgG concentration in serum (A), individual IgG isotypes (B), and mean total serum IgG concentration (C) was determined by ELISA in the indicated mice. (D) Sera from 11-wk-old male mice were subjected to an autoantigen microarray. Heat map of IgG antibody reactivity to indicated autoantigens in pDC-sufficient (BXSB.DTR–, DT) and pDC-depleted (BXSB.DTR+, DT) mice. Each column represents an individual mouse; each row indicates a single antigen. Relative maximum row signals are shown in red; relative minimum row signals are shown in blue. (E) Normalized signal of serum IgG reactivity for indicated antigens, as analyzed by autoantigen microarray described in (D). Serum autoantibodies (IgG) were analyzed by autoantigen microarray as in (D) and normalized signals for the indicated antigens are shown. Data points represent individual mice. Bar indicates arithmetic mean. *, P < 0.5; **, P < 0.01; ***, P < 0.001. Absence of * indicates nonsignificant differences.