Fig. 3.

VacA and the enzymatic activity of GGT contribute to neonatally acquired immune tolerance independently of T cells. (A) C57BL/6 mice were infected with H. pylori PMSS1 as neonates (iN) for 6 wk. One group received acivicin continuously every other day starting from the day of infection (acivicin_cont). Another group received acivicin only during the last 2 wk of infection. CD11c⁺ MLN DCs were cocultured with CD4⁺CD25⁻ T cells, and cocultures were stained for CD4, CD25, and FoxP3. CD25 and FoxP3 staining of the CD4⁺ gate is shown for all donors. (B) TCR-β^−/− mice were infected with H. pylori PMSS1, PMSS1Δggt, or PMSS1ΔvacA at 7 d (iN) or 6 wk of age (iA, infected as adults) for 1 mo. CD25⁺FoxP3⁺ cells in the CD4⁺ gate are shown for DC/T-cell cocultures of all donors. Data in B are pooled from two studies. In A and B, DCs from uninfected mice (ctrl) and T cells cultured in the absence of DCs (−) served as controls.