Salmonella typhimurium interacts with CD209 receptors to promote host dissemination and infection.

Salmonella typhimurium, a Gram-negative bacterium, can cause infectious diseases ranging from gastroenteritis to systemic dissemination and infection. However, the molecular mechanisms underlying this bacterial dissemination have yet to be elucidated. A study indicated that using the lipopolysaccharide (LPS) core as a ligand, S. typhimurium was able to bind human DC-SIGN (hCD209a), a HIV receptor that promotes viral dissemination by hijacking antigen-presenting cells (APCs). In this study, we showed that S. typhimurium interacted with CD209s, leading to the invasion of APCs and potentially the dissemination to regional lymph nodes, spleen and liver in mice. Shielding of the exposed LPS core through the expression of O-antigen reduces dissemination and infection. Thus, we propose that similar to HIV, S. typhimurium may also utilize APCs via interactions with CD209s as a way to disseminate to the lymph nodes, spleen and liver to initiate host infection.