Purpose: Dendritic cells regulate immune responses to microbial products. We assessed effects of bacterial DNA in the clinically-effective probiotic preparation, VSL#3, on activation, cytokine production and T-cell stimulatory capacity of human dendritic cells. Methods: Whole blood and enriched dendritic cells were cultured with bacterial DNA in the presence or absence of Toll-like receptor antibodies. Expression of Toll-like receptor 9 and activation markers (CD40, CCR7) on CD11c+ (myeloid) and CD11c- (plasmacytoid) dendritic cells was analysed by flow cytometry. Cytokine production was assessed by intracellular staining and ELISA. Activation of naive allogeneic CD4+ T-cells was measured in mixed leukocyte reactions. Results: Probiotic bacterial DNA activated plasmacytoid and myeloid dendritic cells as indicated by enhanced CD40 and CCR7 expression. Probiotic bacterial DNA enhanced interleukin-10 production by myeloid dendritic cells using pathways involving Toll-like receptor 9 and inhibited dendritic cells' ability to stimulate naive T-cells. Conclusions: Probiotic bacterial DNA induces an immunoregulatory rather than a pro-inflammatory cytokine profile in dendritic cells, suggesting that beneficial effects of probiotic bacteria are mediated in part by their DNA. These results suggest that the release of bacterial DNA from the microflora as a result of physiologically occurring bacterial lysis may be involved in intestinal immune homeostasis.

Probiotic bacterial DNA induces interleukin-10 production by human dendritic cells via toll-like receptor 9

BRIGIDI, PATRIZIA;GIONCHETTI, PAOLO;VITALI, BEATRICE;RIZZELLO, FERNANDO;CAMPIERI, MASSIMO;
2012

Abstract

Purpose: Dendritic cells regulate immune responses to microbial products. We assessed effects of bacterial DNA in the clinically-effective probiotic preparation, VSL#3, on activation, cytokine production and T-cell stimulatory capacity of human dendritic cells. Methods: Whole blood and enriched dendritic cells were cultured with bacterial DNA in the presence or absence of Toll-like receptor antibodies. Expression of Toll-like receptor 9 and activation markers (CD40, CCR7) on CD11c+ (myeloid) and CD11c- (plasmacytoid) dendritic cells was analysed by flow cytometry. Cytokine production was assessed by intracellular staining and ELISA. Activation of naive allogeneic CD4+ T-cells was measured in mixed leukocyte reactions. Results: Probiotic bacterial DNA activated plasmacytoid and myeloid dendritic cells as indicated by enhanced CD40 and CCR7 expression. Probiotic bacterial DNA enhanced interleukin-10 production by myeloid dendritic cells using pathways involving Toll-like receptor 9 and inhibited dendritic cells' ability to stimulate naive T-cells. Conclusions: Probiotic bacterial DNA induces an immunoregulatory rather than a pro-inflammatory cytokine profile in dendritic cells, suggesting that beneficial effects of probiotic bacteria are mediated in part by their DNA. These results suggest that the release of bacterial DNA from the microflora as a result of physiologically occurring bacterial lysis may be involved in intestinal immune homeostasis.
2012
K. M. Lammers; A. L. Hart; P. Brigidi; P. Gionchetti; B. Vitali; H. O. Al-Hassi; N. English; F. Rizzello; S. Stagg; M. Campieri; S. C. Knight; M. A. Kamm; A. J. Stagg
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/121659
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? ND
social impact