<i>H</i>. <i>pylori</i> uses its T4SS for T_reg cell induction and bacterial persistence.

<p>WT and B7-H1^-/- C57BL/6 mice were challenged with <i>H</i>. <i>pylori</i> strain PMSS1, or with <i>H</i>. <i>pylori</i> SS1. Mice were sacrificed after 4 weeks of infection. (A) Blood were collected and IL-10 was analyzed using luminex bead array. Data represents as mean ± SD (n = 12); *<i>P <</i>. <i>05</i>. Expression of (B) IL-10 and (C) FoxP3 mRNA in the mouse stomach was done by RT-PCR. (D) Infection rate was determined by quantification of <i>H</i>. <i>pylori</i> genome copy per half of antrum based on the analysis of <i>H</i>. <i>pylori</i> 16S gene amplification by real time PCR. Average bar of infection rate were calculated from five mice per group and demonstrated as a mean ± SD.