<i>In situ</i> T lymphocyte responses in colonic sections of Mongolian gerbils 14 months following <i>H. pylori</i> infection.

<p>Mongolian gerbils were infected with <i>H. pylori</i> wildtype strain B8 (B8; middle) or <i>H. pylori</i> mutant strain lacking <i>cagY</i> (B8Δ<i>cagY</i>; right). Fourteen months following infection, colonic biopsies were taken and paraffin sections stained for CD3 by immunohistochemistry to visualize T lymphocytes <i>in situ</i>. Uninfected age-matched animals served as negative controls (Naïve; left). Representative photomicrographs of positively stained cells are shown (200 x magnification, scale bar 50 µm).