S-layer proteins as immune players: tales from pathogenic and non-pathogenic bacteria

ASSANDRI, MATÍAS H.; MALAMUD, MARIANO; TREJO, FERNANDO M.; SERRADELL, MARÍA DE LOS A

Current Research in Microbial Sciences

ELSEVIER

Año: 2023

2666-5174

In bacteria, as in other microorganisms, surface compounds interact with different patternrecognition receptors expressed by host cells, which usually triggers a variety of cellular responsesthat result in immunomodulation. The S-layer is a two-dimensional macromolecular crystallinestructure formed by (glyco)-protein subunits that covers the surface of many species of Bacteriaand almost all Archaea. In Bacteria, the presence of S-layer has been described in bothpathogenic and non-pathogenic strains. As surface components, special attention deserves therole that S-layer proteins (SLPs) play in the interaction of bacterial cells with humoral and cellularcomponents of the immune system. In this sense, some differences can be predicted betweenpathogenic and non-pathogenic bacteria. In the first group, the S-layer constitutes an importantvirulence factor, which in turn makes it a potential therapeutic target. For the other group, thegrowing interest to understand the mechanisms of action of commensal microbiota and probioticstrains has prompted the studies of the role of the S-layer in the interaction between the hostimmune cells and bacteria bearing this surface structure. In this review, we aim to summarize themain latest reports and the perspectives of bacterial SLPs as immune players, focusing on thosefrom pathogenic and commensal/probiotic most studied species