Intracellular growth of wild type and mutant strains in U937 cells.

<p>The growth of wild type, the <i>ssaS</i>::Km and <i>sscA</i>::Km mutants were compared in HLA-B27-transfected (A) or HLA-A2-transfected U937 cells (B). The comparison for the mutant <i>ssaS</i>::Km growth in HLA-B27 and HLA-A2 cells (C) and for the mutant <i>sscA</i>::Km growth in HLA-B27 and HLA-A2 cells (D) was shown. Values represented the mean and standard deviation of at least three independent experiments with duplicate samples. *, ** and *** indicate <i>P</i><0.05, <0.01 and <0.001, respectively, when the mutant-infected cells compared to the wild type (WT)-infected cells (A and B) or the mutant-infected HLA-B27 cells to HLA-A2 cells (C and D). Data were compared using Student's paired 2-tailed <i>t</i>-test.