Colocalization of CD4⁺ and CD8⁺ lymphocytes with F4/80⁺ macrophages increases as infection with <i>Salmonella</i> persists.

<p>Mice were infected i.v. with 1x10⁵ CFUs of <i>Salmonella</i> and at day 0 (uninfected control), 6, 9, and 21, spleen tissue sections were stained with antibodies specific for CD4 and CD8 lymphocyte markers, as well as the F4/80 macrophage marker. Stained sections were analyzed with Volocity software and data are expressed as the percentage of pixels positive for the CD4 or CD8 marker colocalizing with pixels positive for the F4/80 cell marker (A). (B) Percentage of F4/80⁺ pixels colocalizing with CD4⁺ and CD8⁺ pixels. (C) A representative image of in situ colocalization of CD4⁺ lymphocytes (top panel, green) with F4/80⁺ macrophages (top panel, red) and CD8⁺ lymphocytes (bottom panel, green) with F4/80⁺ macrophages (bottom panel, red). Five images from individual mice were analyzed (n = 3 mice per time point). Data are expressed as the mean ± standard deviation. Group means that do not share a subscript are significantly different (p< 0.05).