Fig. 1.

Blockade of PI3Kγ activity significantly reduces the entry of L. mexicana parasites into macrophages and neutrophils in vitro and in vivo. Quantification of intracellular promastigotes in BMDMs (A), PMNs (B), and HMDMs (C) by fluorescence microscopy. (D) Quantification of intracellular axenic amastigotes in BMDMs by fluorescence microscopy. Cells were treated with AS-605240 (1.25 M) or saline before infection with CFSE-labeled parasites. At least 1,000 cells were enumerated for each time point. Data are expressed as the mean number of intracellular parasites per 100 cells ± SE from two independent experiments. *P < 0.05 as determined by an unpaired Student's t test. (E) Quantification of intracellular parasites in BMDMs and PMNs by flow cytometry. Mice were infected by inoculating 4 × 10⁶ CFSE-labeled promastigotes (F) or IgG-coated axenic amastigotes (G) into air pouches in the presence or absence of AS-605240 (15 mg/kg, administered i.p.). Cells were obtained by lavage and stained for macrophage and neutrophils using antibodies against the cell surface markers CD68 and GR1, respectively. Data are representative of results from one of three independent experiments with similar results.