FIG 6.
The Asp14 C terminus is important for the ability of A. phagocytophilum to exploit host cell surface disulfide bond reductase activity. A. phagocytophilum bacteria were treated with rabbit preimmune serum or rabbit antiserum (α) specific for Asp14113–124, AipA9–21, or OmpA59–74, followed by incubation with HL-60 cells in the continued presence of antiserum with or without TCEP. At 24 h, the cells were examined by immunofluorescence microscopy for the percentages of infected cells (A) and numbers of ApVs per cell (B). Data are presented as the mean values ± SD from triplicate samples and are representative of experiments performed three separate times. Statistically significant values are indicated. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. Asterisks above columns indicate statistically significant differences in levels of infection relative to the results for preimmune serum-treated cells, while asterisks over the horizontal brackets denote a statistically significant difference between the levels of infection of Asp14113–124 antiserum-treated cells following incubation in the absence or presence of TCEP.