Biology subjects

Turnbaugh, J. A.

Publications and source records attributed to Turnbaugh, J. A..

4 recordsLinked to original sources

bioRxiv2025

A20's Linear Ubiquitin Binding Motif Restrains Pathogenic Activation of TH17/22 cells and IL-22 Driven Enteritis

A20, encoded by the TNFAIP3 gene, is a protein linked to Crohns disease and celiac disease in humans. We now find that mice expressing point mutations in A20s M1 ubiquitin binding motif (ZF7) spontaneously develop proximate enteritis that requires both luminal microbes and T cells. Cellular and transcriptomic profiling reveal expansion of TH17/22 cells and aberrant expression of IL-17A and IL-22 in intestinal lamina propria of A20ZF7 mice. While deletion of IL-17A from A20ZF7/ZF7 mice exacerbates enteritis, deletion of IL-22 abrogates intestinal epithelial cell hyperproliferation, barrier dysfunction, and alarmin expression. A20ZF7/ZF7 TH17/22 cells autonomously express more ROR{psi}t and IL-22 after differentiation in vitro. ATAC sequencing identified an enhancer region upstream of the Il22 gene in A20ZF7/ZF7 T cells, and this enhancer demonstrated increased activating histone acetylation coupled with exaggerated Il22 transcription. Finally, CRISPR/Cas9-mediated ablation of A20ZF7 in human T cells increases ROR{psi}t expression and IL22 transcription. These studies link A20s M1 ubiquitin binding function with ROR{psi}t expression, epigenetic activation of TH17/22 cells, and IL-22 driven enteritis.

immunology↗

bioRxiv2024

Expansion of a bacterial operon during cancer treatment ameliorates drug toxicity

Dose-limiting toxicities remain a major barrier to drug development and therapy, revealing the limited predictive power of human genetics. Herein, we demonstrate the utility of a more comprehensive approach to studying drug toxicity through longitudinal study of the human gut microbiome during colorectal cancer (CRC) treatment (NCT04054908) coupled to cell culture and mouse experiments. 16S rRNA gene sequencing revealed significant shifts in gut microbial community structure during oral fluoropyrimidine treatment across multiple patient cohorts, in mouse small and large intestinal contents, and in patient-derived ex vivo communities. Metagenomic sequencing revealed marked shifts in pyrimidine-related gene abundance during oral fluoropyrimidine treatment, including enrichment of the preTA operon, which is sufficient for the inactivation of active metabolite 5-fluorouracil (5-FU). preTA+ bacteria depleted 5-FU in gut microbiota grown ex vivo and the mouse distal gut. Germ-free and antibiotic-treated mice experienced increased fluoropyrimidine toxicity, which was rescued by colonization with the mouse gut microbiota, preTA+ E. coli, or preTA-high CRC patient stool. Finally, preTA abundance was negatively associated with fluoropyrimidine toxicity in patients. Together, these data support a causal, clinically relevant interaction between a human gut bacterial operon and the dose-limiting side effects of cancer treatment. Our approach is generalizable to other drugs, including cancer immunotherapies, and provides valuable insights into host-microbiome interactions in the context of disease. One Sentence Summary: Gut microbial enzymes can be used to predict and prevent anticancer drug toxicity.

systems biology↗

bioRxiv2023

A diet-dependent host metabolite shapes the gut microbiota to protect from autoimmunity

Diet can protect from autoimmune disease; however, whether diet acts via the host and/or microbiome remains unclear. Here, we use a ketogenic diet (KD) as a model to dissect these complex interactions. A KD rescued the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis in a microbiota-dependent fashion. Dietary supplementation with a single KD-dependent host metabolite ({beta}-hydroxybutyrate, {beta}HB) rescued EAE whereas transgenic mice unable to produce {beta}HB in the intestine developed more severe disease. Transplantation of the {beta}HB-shaped gut microbiota was protective. Lactobacillus sequence variants were associated with decreased T helper 17 (Th17) cell activation in vitro. Finally, we isolated a L. murinus strain that protected from EAE, which was phenocopied by the Lactobacillus metabolite indole lactic acid. Thus, diet alters the immunomodulatory potential of the gut microbiota by shifting host metabolism, emphasizing the utility of taking a more integrative approach to study diet-host-microbiome interactions.

microbiology↗

bioRxiv2019

Diet induces reproducible alterations in the mouse and human gut microbiome

The degree to which diet reproducibly alters the human and mouse gut microbiota remains unclear. Here, we focus on the consumption of a high-fat diet (HFD), one of the most frequently studied dietary interventions in mice. We employed a subject-level meta-analysis framework for unbiased collection and analysis of publicly available 16S rRNA gene and metagenomic sequencing data from studies examining HFD in rodent models. In total, we re-analyzed 27 studies, 1101 samples, and 106 million reads mapping to 16S rRNA gene sequences. We report reproducible changes in gut microbial community structure both within and between studies, including a significant increase in the Firmicutes phylum and decrease in the Bacteroidetes phylum; however, reduced alpha diversity is not a consistent feature of HFD. Finer taxonomic analysis revealed that the strongest signal of HFD on microbiota species composition is Lactococcus spp., which we demonstrate is a common dietary contaminant through the molecular testing of dietary ingredients, culturing, microscopy, and germ-free mouse experiments. After in silico removal of Lactococcus spp., we employed machine learning to define a unique operational taxonomic unit (OTU)-based signature capable of predicting the dietary intake of mice and demonstrate that phylogenetic and gene-family transformations of this model are capable of accurately predicting human samples in controlled feeding settings (area under the receiver operator curve = 0.75 and 0.88 respectively). Together, these results demonstrate the utility of microbiome meta-analyses in identifying robust bacterial signals for mechanistic studies and creates a framework for the routine meta-analysis of microbiome studies in preclinical models.

microbiology↗