Aggregating Phenotype in Lactobacillus crispatus Determines Intestinal Colonization and TLR2 and TLR4 Modulation in Murine Colonic Mucosa

Abstract

The colonic microbiota is a major modulator of the mucosal immune system; therefore, its manipulation through supplementation with probiotics may significantly affect the host's immune responses. Since different probiotics seem to exert various effects in vivo, we tested the relevance of the autoaggregation phenotype on the intestinal persistence of lactobacilli and their ability to modulate the host's innate immune responses. After 14 days of diet supplementation, the aggregating strain Lactobacillus crispatus M247 but not aggregation-deficient isogenic mutant MU5 was recovered from the feces and colonic mucosa of mice. This observation was confirmed by strain-specific PCR amplification and by Lactobacillus-specific denaturing gradient gel electrophoresis analysis. Indeed, L. crispatus M247 increased Toll-like receptor 2 (TLR2) mRNA levels, while it reduced TLR4 mRNA and protein levels in the colonic mucosa, whereas MU5 was ineffective. In colonic epithelial cells (CMT-93 cells) L. crispatus M247 but not MU5 induced time-dependent extracellular signal-regulated kinase-1 (ERK1) tyrosine phosphorylation and TLR modulation, which were abolished in the presence of PD98059 (an ERK1 inhibitor). To assess the functional relevance of probiotic-induced TLR modulation, we determined the consequences of L. crispatus preexposure on TLR4 (lipopolysaccharide [LPS]) and TLR2 [Pam 3 Cys-Ser-(Lys) 4 ] ligand-mediated effects in intestinal epithelial cells. Preexposure to L. crispatus M247 blunted LPS-induced interleukin-6 (IL-6) release and inhibition of CMT-93migration over a wound edge, whereas it enhanced TLR2-mediated IL-10 up-regulation. In summary, the aggregation phenotype is required for L. crispatus persistence in the colon and for modulation of TLR2/TLR4 expression through an ERK-dependent pathway. We speculate that the aggregation phenotype in L. crispatus M247 is required to temper epithelial cell responsiveness to bacterial endotoxins, which thus affects the evolution of intestinal inflammatory processes.

In vitro characterization of aggregation and adhesion properties of viable and heat-killed forms of two probiotic Lactobacillus strains and interaction with foodborne zoonotic bacteria, especially Campylobacter jejuni

“…Furthermore the aggregating strain Lactobacillus crispatus M 247 was recovered from the faeces and colonic mucosa of mice after 14 days of diet supplementation but an In vitro properties of two probiotic Lactobacillus aggregation-deficient isogenic mutant MU5 was absent, leading to the conclusion that the aggregation phenotype in Lb. crispatus determines intestinal colonization in murine colonic mucosa (Voltan et al, 2007). These in vivo studies indicate that bacteria with aggregating phenotypes persist longer in the gastrointestinal tract compared with nonaggregating phenotype and that adhesion and aggregation appear to be correlated.…”

“…farciminis 3699 involves carbohydrate-lectin interactions and/or proteinaceous components present on the surface. Autoaggregation is a known property of some Lactobacillus isolates (Collado et al, 2007(Collado et al, , 2008 and allows the formation of biofilm in the gastrointestinal tract which contributes, as a physico-chemical barrier, to the preservation of the intestinal wall, along with the stimulation of the immune system (Jankovic et al, 2003;Castagliuolo et al, 2005;Voltan et al, 2007;Turpin et al, 2010), and to protection against colonization by pathogenic bacteria (Collado et al, 2007(Collado et al, , 2008. Furthermore, bacteria with a high autoaggregation potential will more easily colonize the intestinal and urogenital tracts (Boris et al, 1998;Cesena et al, 2001;Collado et al, 2005Collado et al, , 2007Collado et al, , 2008.…”

“…Several workers have suggested that the ability of beneficial micro-organisms to aggregate and adhere aids in colonization of the gut and in the establishment of a barrier which prevents enteropathogens from establishing an infection. Factors which prevent infection include the physical presence of beneficial micro-organisms and modulation of the gut immune system by these organisms (Cesena et al, 2001;Voltan et al, 2007;Collado et al, 2008;Sherman et al, 2009).…”

Identification and Characterization of Bile Salt Hydrolyzing Lactobacillus Isolates

“…Hence, based on cell surface hydrophobicity, only 9 isolates (LBF 01, LBF 05, LBF 08, LBF 11, LBF 13 A, LBF 20, LBF89, LBF90, LBF91) were selected for further characterization.Cell adhesion, a multistep process, involves contact of the bacterial cell membrane and intermingling surfaces while aggregation may take place between cells of the same strain (auto-aggregation) or between different species and strains (co-aggregation). Aggregation has been considered as an important mechanism for genetic exchange, adhesion, and colonization in the host environments, as well as Immuno modulation of colonic mucosa (Cesena et al, 2001, Voltan et al, 2007. Savedboworn et al, (2014) concluded that most of the LAB exhibited a strong autoaggregation after 5 h of incubation like KMUTNB 5-8 strain showed highest autoaggregation ability of 96.09%.…”

Characterization of surface molecules from bacterial cells involved in the potential probiotic activity of natural lactobacilli isolates

“…Zahvaljujući sposobnosti agregacije, soj Lb. crispatus M247 bolje preživljava u debelom crevu od svog mutanta MU5 koji je izgubio tu sposobnost (Voltan et al, 2007). Takođe, Lb.…”