Immune responses to PRT/H or Lys/H complexes. C57Bl/6 mice were immunized with PRT alone (125 μg/mL, n = 10) or PRT/H (125 μg/mL PRT and 12.5 U/mL H, n = 10) and Lys (500 μg/mL, n = 5) or Lys/H (500 μg/mL Lys and 12 U/mL, n = 10). (A-B) Peak antibody responses to PRT/H (panel A) and Lys/H (panel B) occurred within 14 days from start of immunization. (C-D) Specificity of representative seropositive PRT/H (panel C, •) and Lys/H (panel D, ■), and seronegative PRT/H (○) and Lys/H (□) are shown. P values were calculated for panels A and B using an unpaired t test with Welch correction and calculated for panels C and D using a 1-way ANOVA and Bonferroni posttest for calculating differences between conditions. *PRT/H vs BSA, mPF4/H, or Lys/H; **PRT/H vs PRT or Lys; #Lys/H vs BSA, mPF4/H, PRT, or PRT/H; L̂ys vs BSA, mPF4/H, PRT, or PRT/H. Data are representative of > 3 independent immunization experiments involving PRT/H or Lys/H.