Segmented filamentous bacteria (SFB) and Bacteroides fragilis are known to interact with the host immune response through the aryl hydrocarbon receptor (Ahr). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), an environmental toxicant and a high-affinity Ahr ligand has the potential to modify the effect of SFB and B. fragilis. MicroRNAs (miRNA) with their role in regulating gene expression post-transcriptionally, may potentially be used to observe such interactions between SFB, B. fragilis, and TCDD. However, little is known regarding the impact of gut microbial members on miRNA expression or its modulation in the presence of an environmental toxicant. This information is important in understanding toxicant-mediated dysbiosis in gut microbiome and the resulting human health impacts. In this study, C57BL/6 germ-free (GF) mice were colonized with SFB and B. fragilis and administered 30 μg/kg TCDD every 4 d for 28 d and miRNA were measured. Compared to GF mice, colonization with SFB resulted in an increase in up- and down-regulated Ileal miRNAs. TCDD treatment of this group decreased the number of upregulated miRNA and increased the number of down-regulated miRNAs. Association with SFB and B. fragilis together had a similar but less pronounced effect in response to TCDD treatment. TCDD treatment of GF mice had no miRNA expression response. Immune and inflammatory responses and T-cell differentiation were the key functions impacted by these miRNAs. Overall, these results reveal that the host response to toxicants may also depend on the presence of specific gut microbial populations.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8464502 | PMC |
http://dx.doi.org/10.1016/j.scitotenv.2021.149130 | DOI Listing |
Sci Total Environ
November 2021
Center for Microbial Ecology, Michigan State University, East Lansing, MI 48824, USA; Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA; Department of Civil and Environmental Engineering, East Lansing, MI 48824, USA. Electronic address:
Segmented filamentous bacteria (SFB) and Bacteroides fragilis are known to interact with the host immune response through the aryl hydrocarbon receptor (Ahr). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), an environmental toxicant and a high-affinity Ahr ligand has the potential to modify the effect of SFB and B. fragilis.
View Article and Find Full Text PDFIran J Microbiol
June 2020
Department of Microbiology, Virology and Immunology, Zaporizhzhya State Medical University, Zaporizhzhya, Ukraine.
Background And Objectives: Intestinal microbiota is involved in the development and maintenance of immune homeostasis. This study was conducted to investigate the levels of key immunoregulatory bacteria in the intestinal wall-associated microflora and its effect on the transcriptional activity of the Foxp3 and RORyt genes in the gut-associated lymphoid tissue (GALT) of rats with -induced inflammation, both untreated and treated with vancomycin and .
Materials And Methods: To determine the levels of immunoregulatory bacteria in GALT of rats Q-PCR was used to identify them by species-specific 16S rDNA genes.
Front Microbiol
September 2017
Department of Civil and Environmental Engineering, East LansingMI, United States.
Environmental toxicants such as 2,3,7,8-tetrachlorodibenzo--dioxin (TCDD), an aryl hydrocarbon receptor (AhR), are known to induce host toxicity and structural shifts in the gut microbiota. Key bacterial populations with similar or opposing functional responses to AhR ligand exposure may potentially help regulate expression of genes associated with immune dysfunction. To examine this question and the mechanisms for AhR ligand-induced bacterial shifts, C57BL/6 gnotobiotic mice were colonized with and without segmented filamentous bacteria (SFB) - an immune activator.
View Article and Find Full Text PDFSemin Immunopathol
January 2015
Department of Biochemistry, Graduate School of Pharmaceutical Science, Keio University, Tokyo, 105-8512, Japan.
Commensal microbiota shapes the intestinal immune system by regulating T helper (TH) cell lineage differentiation. For example, Bacteroides fragilis colonization not only optimizes the systemic TH1/TH2 balance, but also can induce regulatory T (Treg) cell differentiation in the gut. In addition, segmented filamentous bacteria (SFB) facilitate the development of TH17 cells in the small intestine.
View Article and Find Full Text PDFCurr Opin Immunol
August 2012
Department of Medicine, Division of Rheumatology, Washington University School of Medicine, St. Louis, MO 63110, United States.
The commensal bacteria normally resident in the gastrointestinal tract represent an enormous pool of foreign antigen within the body. Although mechanical barriers limit entry of bacteria into the host, recent data suggest that T cells routinely interact with commensal bacteria using both antigen-specific and non-specific receptors. Depending on the bacterial species, either regulatory or effector T cell responses can be generated.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!