Figure 2. Role of FcR-mediated pathways in ADRB induction.

Serum was collected from BALB/c and C57BL/6 mice immunized with Ad-M PyMSP1₄₂ or BALB/c mice immunized with three doses of PyMSP1₁₉-GST with AdjuPhos (PPP) or one dose AdHu5-PyMSP1₄₂, followed by one dose PyMSP1₁₉ with AdjuPhos (AP). Assays were set up with 10 μg/mL PyMSP1₁₉-GST-coated plates, 50 μL/well neutrophils at 1 × 10⁷ PMNs/mL and serum diluted 1:100 in PBS run in duplicate wells. Neutrophils were isolated from the bone marrow of WT BALB/c and C57BL/6 mice, plus γ^−/− and CD32b^−/− mice on the same genetic backgrounds, respectively. ADRB induction was assessed by: (A) BALB/c and γ^−/− PMNs in response to sera from BALB/c mice immunized with Ad-M PyMSP1₄₂; (B) BALB/c PMNs in response to sera from Ad-M PfMSP1-immunized or naive BALB/c mice (on a PfMSP1₁₉-GST-coated plate), where PMNs had been preincubated with neutrophil buffer (black), control rat IgG (gray), or anti-CD16/32 mAb (white); (C) C57BL/6 and CD32b^−/− PMNs in response to sera from C57BL/6 mice immunized with Ad-M PyMSP1₄₂; and (D) BALB/c PMNs in response to mouse isotype-specific chimeric anti-PfMSP1₁₉ mAb at 8.3 μg/mL (on a PfMSP1₁₉-GST-coated plate). For mice immunized with AP and PPP regimes, (E) PyMSP1₁₉ end-point ELISA titers against PyMSP1₁₉-IMX108-coated plates, (F) IgG1 and IgG2a isotype-specific ELISA titers against the same protein as total IgG, and (G) ADRB activity using BALB/c PMNs were determined. *P < 0.05 (Wilcoxon matched-pairs signed-rank test). Bars and points represent means of two replicates for each sample, and medians on dot plots are shown, represented by lines.