S-layer associated proteins contribute to the adhesive and immunomodulatory properties of Lactobacillus acidophilus NCFM

Abstract

Background: Surface layers (S-layers) are two-dimensional crystalline arrays of repeating proteinaceous subunits that form the outermost layer of many bacterial cell envelopes. Within the Lactobacillus genus, S-layer presence is frequently associated with probiotic-relevant properties such as improved adherence to host epithelial cells and modulation of the immune response. However, recent studies have demonstrated that certain S-layer functions may be supplemented by a novel subset of proteins embedded within its lattice, termed S-layer associated proteins (SLAPs). In the following study, four Lactobacillus acidophilus NCFM SLAPs (LBA0046, LBA0864, LBA1426, and LBA1539) were selected for in silico and phenotypic assessment. Results: Despite lacking any sequence similarity or catalytic domains that may indicate function, the genes encoding the four proteins of interest were shown to be unique to S-layer-forming, host-adapted lactobacilli species. Likewise, their corresponding deletion mutants exhibited broad, host-relevant phenotypes including decreased inflammatory profiles and reduced adherence to Caco-2 intestinal cells, extracellular matrices, and mucin in vitro. Conclusions: Overall, the data presented in this study collectively links several previously uncharacterized extracellular proteins to roles in the underlying host adaptive mechanisms of L. acidophilus.

Development of Resistance to Clarithromycin and Amoxicillin-Clavulanic Acid in Lactiplantibacillus plantarum In Vitro Is Followed by Genomic Rearrangements and Evolution of Virulence

“…This assumption is supported by literature data; changes in the primary structure of a number of genes that turned out to be mutant in L. plantarum 8p-a3-Clr-Amx led to changes in virulence in some bacteria. Thus, deletion of the gene encoding a protein with an immunoglobulin-like domain in Lactobacillus acidophilus led to a decrease in the virulent properties of the bacterium ( 37 ), deletion of the rho gene in Staphylococcus aureus led to an increase in the expression of virulence factors and an increase in the virulent properties of the bacterium against mice ( 38 ), and deletion of the pbp2 gene in Erwinia amylovora led to the loss of virulence against plants ( 39 ). In this regard, to clarify the possibility of changing the virulence status in L. plantarum with the development of antibiotic resistance to amoxicillin-clavulanic acid and clarithromycin, we performed a comparative analysis of the virulence of strains 8p-a3 and 8p-a3-Clr-Amx.…”

Population-wide diversity and stability of serum antibody epitope repertoires against human microbiota

“…4b,d), suggesting also gender differences in the Ig-epitope repertoires against bacteria. Although cell wall-associated proteins such as S-layer proteins 36 or an N-acetylmuramidase were bound in up to 6% of males, binding of these antigens was detected in up to 40% of females (Fig. 4d).…”

The Main Mechanisms of the Effect of Intestinal Microflora on the Immune System and Their Importance in Clinical Practice

“…Генетичні дослідження, проведені зі штамом Lactobacillus acidophilus NCFM, продемонстрували наявність специфічних білків, що асоційовані із S-шаром (SLAP) цього про- біотичного штаму. Саме з цими білками пов'язують імуногенні властивості пробіотика [78,79]. Здатність Lactobacillus acidophilus NCFM виживати при проходженні через травний тракт і взаємодіяти з кишковими та імунними клітинами свідчить про потенціал цього пробіотичного штаму [80].…”