Vi polysaccharide of <i>Salmonella typhi</i> targets the prohibitin family of molecules in intestinal epithelial cells and suppresses early inflammatory responses

Vi capsular polysaccharide (Vi) was first identified as a virulence antigen of Salmonella typhi, the causative agent of typhoid fever in humans; it renders S. typhi resistant to phagocytosis and the action of serum complement. However, the role of Vi during the infection of intestinal epithelium with S. typhi is not completely understood. We show here that Vi can interact with a model human intestinal epithelial cell line, Caco-2, through a cell-surface-associated molecular complex containing two major proteins of 30 and 35 kDa and a minor protein of approximately 68 kDa. The two major proteins were identified as the putative tumor suppressor molecule, prohibitin, and its closely related homolog, B cell receptor-associated protein 37. These two proteins were enriched in…