M1 polarization of gastric macrophages after <i>H. pylori</i> infection.

<p>(A) Expression of genes associated with macrophage polarization in the gastric mucosa of naïve and infected mice was determined by real-time PCR. Symbols represent individual mice, and horizontal bars indicate the medians. *, <i>P</i><0.05 **, <i>P</i><0.01 compared to the expression level in uninfected mice via Mann-Whitney U test. (B) Sorting of gastric lamina propria macrophages (Gate R1 and R2, CD11b⁺Gr1⁻Siglec-F⁻MHC-II⁺), eosinophils (Gate R1 and R3, CD11b⁺Gr1⁻Siglec-F⁺MHC-II⁻) and remaining cells after gating out macrophages and eosinophils (Gate R4, CD11b⁻ and CD11b⁺Gr1⁺) from pooled (n = 3) mice infected for 26 weeks. Contour plots show expression of CD11b versus Gr1 on gated live cells, and expression of Siglec-F versus MHC-II on gated CD11b⁺Gr1⁻ cells before and after sorting. The gates for sorting (R1–R4) are shown in the top contour plots. Numbers by gates depict cell frequencies. Note that in this experiment the few CD103⁺ DCs that fall into the macrophage gate (∼2%, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015018#pone-0015018-g001" target="_blank">Fig. 1A</a>) were not gated out. (C) Real-time PCR analysis of iNOS and CXCL11 mRNA expression by total gastric lamina propria cells pooled from naïve (n = 3) or infected (n = 3, 26 weeks) mice before sorting as well as expression by sorted macrophages (Gate R1 and R2, CD11b⁺Gr1⁻Siglec-F⁻MHC-II⁺, 9×10⁵ cells), eosinophils (Gate R1 and R3, CD11b⁺Gr1⁻Siglec-F⁺MHC-II⁻, 6×10⁵ cells) and remaining cells after gating out macrophages and eosinophils (Gate R4, CD11b⁻ and CD11b⁺Gr1⁺, 3×10⁶ cells) from infected mice. Bars are the mean of two to three replicates, and dots represent each replicate. Undet., undetected. MΦ, macrophages. Eos, eosinophils.