Evidence of multi-nucleated intracellular amastigotes.

<p>A. Images of THP-1 cells infected with wild type, <b>Δ</b><i>kh1</i>mutants, and <b>Δ</b><i>kh1</i>[int<i>Kh1</i>] add-back axenic amastigotes at 3 days post infection. For this experiment, a 10:1 ratio of axenic amastigotes to macrophage was used. Multinucleate parasites are indicated by arrowheads (2N) and chevrons (>2N). Bottom, close-up of cells with single or multiple nuclei. N = Nuclei. Scale bars, 3 <b>μ</b>m. B. Quantification by microscopy of multi-nucleated intracellular amastigotes. For all time points, the number of intracellular amastigotes examined for each line was >300. Percentages of parasites with 1, 2, and >2 nuclei are indicated as designated by the graph legend at the right. The p-values were calculated for the number of cells with more than two nuclei (>2N) between the different cell lines at Day 5: wt vs. <b>Δ</b><i>kh1</i> mutants, p<<0.01; <b>Δ</b><i>kh1</i> mutants vs. <b>Δ</b><i>kh1</i>[int<i>Kh1</i>], p<<0.01; wt vs. <b>Δ</b><i>kh1</i>[int<i>Kh1</i>], p = 0.8. The p-value calculated for the number of cells with more than two nuclei (>2N) between the different cell lines at Day 5 were as follows: wild type versus <b>Δ</b><i>kh1</i> mutants, p<0.01; <b>Δ</b><i>kh1</i> mutants versus <b>Δ</b><i>kh1</i>[int<i>Kh1</i>], p<0.01; wild type versus <b>Δ</b><i>kh1</i>[int<i>Kh1</i>], p = 0.8.