Fig. 7. AP3 is a virulence factor. (A) In vitro growth of promastigotes. Data shown represent the means ± s.d. from three independent series of measurements. (B) Western blot analysis with metacyclic-specific anti-HASPB antibody. EF1- was used as a loading control. Molecular masses are indicated on the right. (C) In-vitro-macrophage-infectivity assay. Stationary-phase parasites were used to infect explanted mouse peritoneal macrophages at a 3:1 ratio for 4 hours. The proportion of infected macrophages (left) and the number of parasites per infected macrophage (right) were determined after 5 days of incubation. Data shown represent are the means ± s.d. from triplicate infections. *, results for ap3 cells that differ significantly from those for the other two cell lines (t-test, P<0.05). (D) Infection of CD1 mice with wild-type and transgenic stationary-phase L. major promastigotes. Mice were challenged with 5x10⁵ parasites in the left hind footpad. The swelling caused by the respective cell lines was recorded. Data shown represent mean lesion depth ± s.d. from groups of six mice.