Limits...
Microbiota/host crosstalk biomarkers: regulatory response of human intestinal dendritic cells exposed to Lactobacillus extracellular encrypted peptide.

Bernardo D, Sánchez B, Al-Hassi HO, Mann ER, Urdaci MC, Knight SC, Margolles A - PLoS ONE (2012)

Bottom Line: Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria.These peptides may be used for the development of nutraceutical products for patients with IBD.In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis.

View Article: PubMed Central - PubMed

Affiliation: Antigen Presentation Research Group, Imperial College London, Harrow, United Kingdom.

ABSTRACT
The human gastrointestinal tract is exposed to a huge variety of microorganisms, either commensal or pathogenic; at this site, a balance between immunity and immune tolerance is required. Intestinal dendritic cells (DCs) control the mechanisms of immune response/tolerance in the gut. In this paper we have identified a peptide (STp) secreted by Lactobacillus plantarum, characterized by the abundance of serine and threonine residues within its sequence. STp is encoded in one of the main extracellular proteins produced by such species, which includes some probiotic strains, and lacks cleavage sites for the major intestinal proteases. When studied in vitro, STp expanded the ongoing production of regulatory IL-10 in human intestinal DCs from healthy controls. STp-primed DC induced an immunoregulatory cytokine profile and skin-homing profile on stimulated T-cells. Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria. These peptides may be used for the development of nutraceutical products for patients with IBD. In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis.

Show MeSH

Related in: MedlinePlus

STp primes human intestinal DC towards a regulatory phenotype.a) DC were identified in total colonic lamina propria mononuclear cells from healthy controls by flow cytometry according to the Forward and Side scatters and the subsequent HLA-DR/lineage cocktail dot plot. DC were defined as HLA-DR+ and lineage– (CD3, CD14, CD16, CD19 and CD34). b) Ongoing intracellular IL-10 and IL-12(p40/p70) cytokine production (closed histograms) was determined in colonic DC cultured with and without STp (10 µg/ml). Pooled data of 8 independent experiments are shown in panel c). d) Stimulatory capacity of such intestinal DC was determined upon 5 days culture in the presence of allogeneic CFSE-labelled T-cells as stated in Figure 2c. Results show the mean±SEM of 8 independent experiments. e) Imprinted homing profile (gut-homing: β7; skin-homing: CLA) and intracellular cytokine content (IL-10 and IFNγ) of stimulated T-cells (CFSElow) was compared to resting T-cells cultured in the absence of intestinal DC. Pooled data of eight independent experiments is shown in panel f). Closed histograms represent the percentage of positive cells after subtraction from respective isotypes. Lines and bars represent mean±SEM.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3351486&req=5

pone-0036262-g003: STp primes human intestinal DC towards a regulatory phenotype.a) DC were identified in total colonic lamina propria mononuclear cells from healthy controls by flow cytometry according to the Forward and Side scatters and the subsequent HLA-DR/lineage cocktail dot plot. DC were defined as HLA-DR+ and lineage– (CD3, CD14, CD16, CD19 and CD34). b) Ongoing intracellular IL-10 and IL-12(p40/p70) cytokine production (closed histograms) was determined in colonic DC cultured with and without STp (10 µg/ml). Pooled data of 8 independent experiments are shown in panel c). d) Stimulatory capacity of such intestinal DC was determined upon 5 days culture in the presence of allogeneic CFSE-labelled T-cells as stated in Figure 2c. Results show the mean±SEM of 8 independent experiments. e) Imprinted homing profile (gut-homing: β7; skin-homing: CLA) and intracellular cytokine content (IL-10 and IFNγ) of stimulated T-cells (CFSElow) was compared to resting T-cells cultured in the absence of intestinal DC. Pooled data of eight independent experiments is shown in panel f). Closed histograms represent the percentage of positive cells after subtraction from respective isotypes. Lines and bars represent mean±SEM.

Mentions: Having established that STp is a secreted peptide produced by L. plantarum, resistant to intestinal proteolysis, found in the human colonic microenvironment and capable of modulating phenotype and function of human blood-enriched DCs, we next studied its effect on human gut DCs. In contrast to effects on blood-enriched DCs, optimum effects of STp were elicited at a concentration of 1 µg/ml (data not shown). Similar to blood-enriched DCs, STp priming expanded ongoing production of regulatory IL-10 in human intestinal DCs (Figure 3a and 3b).


Microbiota/host crosstalk biomarkers: regulatory response of human intestinal dendritic cells exposed to Lactobacillus extracellular encrypted peptide.

Bernardo D, Sánchez B, Al-Hassi HO, Mann ER, Urdaci MC, Knight SC, Margolles A - PLoS ONE (2012)

STp primes human intestinal DC towards a regulatory phenotype.a) DC were identified in total colonic lamina propria mononuclear cells from healthy controls by flow cytometry according to the Forward and Side scatters and the subsequent HLA-DR/lineage cocktail dot plot. DC were defined as HLA-DR+ and lineage– (CD3, CD14, CD16, CD19 and CD34). b) Ongoing intracellular IL-10 and IL-12(p40/p70) cytokine production (closed histograms) was determined in colonic DC cultured with and without STp (10 µg/ml). Pooled data of 8 independent experiments are shown in panel c). d) Stimulatory capacity of such intestinal DC was determined upon 5 days culture in the presence of allogeneic CFSE-labelled T-cells as stated in Figure 2c. Results show the mean±SEM of 8 independent experiments. e) Imprinted homing profile (gut-homing: β7; skin-homing: CLA) and intracellular cytokine content (IL-10 and IFNγ) of stimulated T-cells (CFSElow) was compared to resting T-cells cultured in the absence of intestinal DC. Pooled data of eight independent experiments is shown in panel f). Closed histograms represent the percentage of positive cells after subtraction from respective isotypes. Lines and bars represent mean±SEM.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3351486&req=5

pone-0036262-g003: STp primes human intestinal DC towards a regulatory phenotype.a) DC were identified in total colonic lamina propria mononuclear cells from healthy controls by flow cytometry according to the Forward and Side scatters and the subsequent HLA-DR/lineage cocktail dot plot. DC were defined as HLA-DR+ and lineage– (CD3, CD14, CD16, CD19 and CD34). b) Ongoing intracellular IL-10 and IL-12(p40/p70) cytokine production (closed histograms) was determined in colonic DC cultured with and without STp (10 µg/ml). Pooled data of 8 independent experiments are shown in panel c). d) Stimulatory capacity of such intestinal DC was determined upon 5 days culture in the presence of allogeneic CFSE-labelled T-cells as stated in Figure 2c. Results show the mean±SEM of 8 independent experiments. e) Imprinted homing profile (gut-homing: β7; skin-homing: CLA) and intracellular cytokine content (IL-10 and IFNγ) of stimulated T-cells (CFSElow) was compared to resting T-cells cultured in the absence of intestinal DC. Pooled data of eight independent experiments is shown in panel f). Closed histograms represent the percentage of positive cells after subtraction from respective isotypes. Lines and bars represent mean±SEM.
Mentions: Having established that STp is a secreted peptide produced by L. plantarum, resistant to intestinal proteolysis, found in the human colonic microenvironment and capable of modulating phenotype and function of human blood-enriched DCs, we next studied its effect on human gut DCs. In contrast to effects on blood-enriched DCs, optimum effects of STp were elicited at a concentration of 1 µg/ml (data not shown). Similar to blood-enriched DCs, STp priming expanded ongoing production of regulatory IL-10 in human intestinal DCs (Figure 3a and 3b).

Bottom Line: Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria.These peptides may be used for the development of nutraceutical products for patients with IBD.In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis.

View Article: PubMed Central - PubMed

Affiliation: Antigen Presentation Research Group, Imperial College London, Harrow, United Kingdom.

ABSTRACT
The human gastrointestinal tract is exposed to a huge variety of microorganisms, either commensal or pathogenic; at this site, a balance between immunity and immune tolerance is required. Intestinal dendritic cells (DCs) control the mechanisms of immune response/tolerance in the gut. In this paper we have identified a peptide (STp) secreted by Lactobacillus plantarum, characterized by the abundance of serine and threonine residues within its sequence. STp is encoded in one of the main extracellular proteins produced by such species, which includes some probiotic strains, and lacks cleavage sites for the major intestinal proteases. When studied in vitro, STp expanded the ongoing production of regulatory IL-10 in human intestinal DCs from healthy controls. STp-primed DC induced an immunoregulatory cytokine profile and skin-homing profile on stimulated T-cells. Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria. These peptides may be used for the development of nutraceutical products for patients with IBD. In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis.

Show MeSH
Related in: MedlinePlus