Fig. 6.

In vivo reduction in Tregs results in poor pregnancy outcome specific to fetal antigens. (A) Percentage male fetuses determined for each litter of C57BL/6 × C57BL/6 by PCR from Saline-treated (●) (n = 8) or denileukin diftitox–treated (○) mice (n = 4). (B) On dpc 18.5, fetal weights determined for fetuses from the above mating. (C) Splenocytes harvested from the saline-treated (●) (n = 5) or denileukin diftitox–treated (○) (n = 4) mice, and cellular proliferation assay performed using 1 × 10⁶ cells per mL to the CD4⁺ T cell peptide epitope of the H-Y antigen presented by I-A^b (10 μM Dby) or the I-A^b presented lysteriolysin peptide epitope (10 μM Lso). Cultures were pulsed with 1 μCi per well ³[H]TdR for the final 18 h of a 72-h culture. Depletion of CD25⁺ cells (Treg) by magnetic bead. Composite fold increase in proliferation with Dby (CD25⁺ depleted)/Dby (whole splenocytes). Statistical difference was determined by two-tailed, unpaired Student's t test (N.S., nonsignificant; *, P < 0.05).