Human neutrophils were incubated with M. catarrhalis RH4 in the presence of A) OmCI-treated serum and SLRPs or BSA or B) OmCI or compstatin-reated serum and OSAD, BGN or BSA for 30 or 60 min at 37°C and 5%CO2. Following incubation total viable bacteria was enumerated following lysis of neutrophils and bacterial survival was calculated by diving CFU at time 30 or 60 with that of time 0. Graphs are presented as the mean and SD of 5 independent experiments and analyzed using a two-way ANOVA with Bonferroni post-hoc tests comparing SLRP/BSA condition to that of no protein control (without, w/o) A) or SLRPs to BSA control B). * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.