Fig 7. Increased activity of human IgG1/IgG3 versions of chimeric anti-PspA antibodies in CDAs with human serum (WU2).

(A-B) 10⁸ CFU/mL of highly encapsulated WU2 were incubated for 15 min in 2.5% unabsorbed human serum pool ± 5 μg/mL of control or chimeric anti-PspA antibodies. Subsequently, C3b deposition was detected with FITC-labeled anti-C3 antibody. Samples were run in triplicate and the FL-1 intensity of the cells measured by flow cytometry. (A) Average MFI values ± SD of one representative experiment of two performed with similar results are shown. ***, p<0.0005, vs. chimeric Fu+ and Fu- hIgG1 versions of 140H1, unpaired Student’s t-test. (B) FL-1 data for 10,000 bacterial particles