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09:25
Isolation and Characterization of Dendritic Cells and Macrophages from the Mouse Intestine
Published on: May 21, 2012
Human intestinal dendritic cells decrease cytokine release against Salmonella infection in the presence of
Miriam Bermudez-Brito1, Sergio Muñoz-Quezada, Carolina Gomez-Llorente
1Institute of Nutrition and Food Technology José Mataix, Biomedical Research Centre, Department of Biochemistry and Molecular Biology II, University of Granada, Granada, Spain.
Plos One
|August 21, 2012
Summary
A novel probiotic, Lactobacillus paracasei CNCM I-4034, and its culture supernatant enhance innate immunity. Both reduced pro-inflammatory cytokines and activated Toll-like receptor (TLR) signaling in human dendritic cells.
Area of Science:
- Immunology
- Microbiology
- Gastroenterology
Background:
- Probiotics modulate immune responses, potentially aiding inflammatory conditions.
- Understanding probiotic signaling pathways in human dendritic cells (DCs) is crucial.
- Human gut DCs differ from monocyte-derived DCs; this study used specific human DCs.
Purpose of the Study:
- Investigate the immune effects of Lactobacillus paracasei CNCM I-4034 on human dendritic cells.
- Determine the role of probiotic bacteria and their cell-free supernatant (CFS) in modulating immune responses.
- Elucidate the signaling pathways involved in probiotic-induced immune modulation.
Main Methods:
- Generated human dendritic cells (DCs) from CD34+ hematopoietic stem cells.
- Challenged DCs with Salmonella in the presence of Lactobacillus paracasei CNCM I-4034 or its CFS.
- Analyzed the expression of pro-inflammatory cytokines, chemokines, and Toll-like receptor (TLR) signaling pathway genes.
Main Results:
- Lactobacillus paracasei CNCM I-4034 and its CFS reduced pro-inflammatory cytokines and chemokines in DCs challenged with Salmonella.
- The CFS was as effective as live bacteria in reducing pro-inflammatory cytokine expression.
- Both bacteria and CFS activated Toll-like receptor (TLR) signaling, including TLR9, CASP8, and TOLLIP gene upregulation.
- The bacterium induced TGF-β2, while the supernatant induced TGF-β1 secretion.
Conclusions:
- Lactobacillus paracasei CNCM I-4034 enhances innate immunity by activating TLR signaling and downregulating pro-inflammatory cytokines.
- The cell-free supernatant of this probiotic offers a safe and effective alternative to live bacteria for functional foods.
- This highlights a novel mechanism for probiotic-mediated immune modulation in the gut.
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