<i>Salmonella</i>-specific B cells form a survival niche supporting in vivo <i>Salmonella</i> spreading to systemic sites.

<p>C57BL/6 mice were adoptively transferred with 0, 2*10⁵ or 10⁶ HEL-specific CD43- naïve B cells labeled with CFSE, as indicated. Mice were orally infected with surface HEL-expressing <i>Salmonella</i> one day after B cell transfer. (A) Distribution of CFSE-labeled HEL-specific B cells in the mesenteric lymph nodes (mLN) and spleen before infection (BI), and 24 or 72 hours post-infection, as indicated. One representative example from 3 experiments with 4 mice for each experimental setting is shown. (B) Recovery of viable bacteria 72 hours post-infection from mesenteric lymph nodes (mLN) spleen (SP) and blood (BL) in infected mice transferred with 0, 2*10⁵ or 10⁶ HEL-specific B cells. Depicted are colony-forming units (CFU)/10⁵ eukaryotic cells. One representative example from 3 experiments with 4 mice for each experimental setting is shown.