Functional role of surface layer proteins of<i> Lactobacillus acidophilus</i> L-92 in stress tolerance and binding to host cell proteins

Abstract

Lactobacillus acidophilus surface layer proteins (SLPs) self-assemble into a monolayer that is non-covalently bound to the outer surface of the cells. There they are in direct contact with the environment, environmental stressors and gut components of the host in which the organism resides. The role of L. acidophilus SLPs is not entirely understood, although SLPs seem to be essential for bacterial growth. We constructed three L. acidophilus L-92 strains, each expressing a mutant of the most abundant SLP, SlpA. Each carried a 12-amino acid c-myc epitope substitution at a different position in the protein. A strain was also obtained that expressed the SlpA paralog SlpB from an originally silent slpB gene. All four strains behaved differently with respect to growth under various stress conditions, such as the presence of salt, ox gall or ethanol, suggesting that SlpA affects stress tolerance in L. acidophilus L-92. Also, the four mutants showed differential in vitro binding ability to human host cell proteins such as uromodulin or dendritic cell (DC)-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN). Furthermore, co-culture of murine immature DCs with a mutant strain expressing one of the recombinant SlpA proteins changed the concentrations of the cytokines IL-10 and IL-12. Our data suggest that SlpA and SlpB of L. acidophilus participate in bacterial stress tolerance and binding to uromodulin or DC-SIGN, possibly leading to effective immune-modification.

Effects and Mechanisms of Resveratrol on the Adhesion of Lactobacillus acidophilus NCFM

“…In order to con rm how RS affects NCFM surface properties, changes in NCFM surface components after RS treatment were evaluated, as it has been showed that the adhesion of Lactobacillus was closely related to the surface components of the strain, such as slps, EPS, and LTA [42,43]. Through the use of gene deletion and overexpression techniques, slps have been shown to signi cantly contribute to adherence in this research [31,44,45], which is consistent with our results. Therefore, slps composition of NCFM may be impacted by RS, which would subsequently in uence surface characteristics and adhesion capacity.…”

Probiotic characterization of Lactiplantibacillus plantarum HOM3204 and its restoration effect on antibiotic-induced dysbiosis in mice

“…These studies showed that the adherent ability of Lactobacillus genus ranged from 2 to 10% (Van Tassell and Miller 2011). Surface layer proteins, hydrophobicity and electrostatic forces promote bacteria to colonize on gut epithelial cells (Gusils et al 2002;Wakai et al 2021). The adherence ability of Lact.…”

Application of a maximal-clique based community detection algorithm to gut microbiome data reveals driver microbes during influenza A virus infection

“…LEfSe analysis of relative abundance of the proteins assigned to “unclassified” function reveals the association of surface-layer proteins with the infected cohort. Acosta et al ( 2019 ) and Wakai et al ( 2021 ) reported that a higher concentration of the surface-layer protein of Lactobacillaceae family inhibits the viral replication. Since the relative abundance of S-layer protein was found to be higher in the infected cohort compared to the healthy cohort, we hypothesize that the S-layer protein might play an instrumental role in combating influenza A infection.…”