Protective Properties of S-layer Protein 2 from 2029 Against Infections

Previously, the protective role of the S-layer protein 2 (Slp2) of the vaginal 2029 (LC2029) strain against foodborne pathogens , serovar Enteritidis, and O157:H was demonstrated. We demonstrate the new roles of the Slp2-positive LC2029 strain and soluble Slp2 against infections. We show that LC2029 bacteria can adhere to the surface of the cervical epithelial HeLa cells, prevent their contact with , and block yeast transition to a pathogenic hyphal form. Surface-bound Slp2 provides the ability for LC2029 to co-aggregate with various strains, including clinical isolates. -induced necrotizing epithelial damage is reduced by colonization with the Slp2-positive LC2029 strain. Slp2 inhibits the adhesion of various strains of to different human epithelial cells, blocks yeast transition to a pathogenic hyphal form, and prevents the colonization and pathogenic infiltration of mucosal barriers. Only Slp2 and LC2029 bacteria stimulate the production of protective human β-defensin 3 in various epithelial cells. These findings support the anti- potential of the probiotic LC2029 strain and Slp2 and form the basis for further research on their ability to prevent and manage invasive infections.