The effect of sialidase treatment on A phagocytophilum binding to PSGL-1^-/- and wild-type murine neutrophils. Binding of FITC-labeled mAb 2H5, which recognizes a subset of sialylated glycans, to PSGL-1^-/- and control neutrophils before (A) and after (B) sialidase treatment. Binding of Cell Tracker Green-labeled, PFA-fixed A phagocytophilum to sialidase-treated and untreated neutrophils from PSGL-1^-/- (C) or control (D) mice. Assays were performed in triplicate. Data are presented as the mean percentage (± SD) of neutrophils bound by 2H5 or bacteria. Representative data from at least 2 studies are presented.