Biology subjects

Westfall, S.

Publications and source records attributed to Westfall, S..

7 recordsLinked to original sources

bioRxiv2026

Early life γδT cell activation enforces intestinal barrier integrity during intergenerational C. difficile colonization

Early postnatal life is a highly dynamic period in which the intestine is inundated with billions of microbes that not only battle for colonization, but also strongly influence immune system function and long-term health. This brief period of development provides a window of opportunity to imprint resilience against disease, yet the intercellular dialogue that dictates tissue protection are only beginning to be discovered. By performing a kinetic analysis of immune cell activation in the colon of mice from early life to adulthood, we identified transient activation of a microbiota-dependent type 3 immune response during the weaning period. This response was characterized by a selective increase in IL-17 production by fetal-derived {gamma}{delta} T cells that occurred in an IL-1 receptor-dependent, cell-intrinsic manner. The subsequent differentiation of IL-10 producing Ror{gamma}t+ T regulatory cells extinguished IL-17 production by {gamma}{delta} T cells and prevented immunopathology. Microbial gain-of-function approaches determined that colonic {gamma}{delta} T cell activation occurred in response to passive acquisition of C. difficile at birth. In turn, IL-17 limited C. difficile growth and intestinal barrier breach by the commensal microbiota. Collectively, our results reveal how an agile immune cell network meets the demands of a maturing microbiota to support gut health during early life. Highlights- Colonic {gamma}{delta}17 T cells are activated during early life in a microbiota-specific manner - Fetal-derived {gamma}{delta}17 T cells require IL-1 signals for activation - Passive acquisition of C.difficile induces {gamma}{delta}17 T cell activation - IL-17 limits C. difficile growth and systemic dissemination of commensals

immunology↗

bioRxiv2024

LRRK2 G2019S mutation incites increased cell-intrinsic neutrophil effector functions and intestinal inflammation in a model of infectious colitis

Parkinsons Disease (PD) is a progressive, neurodegenerative disorder characterised by motor and non-motor symptoms. Emerging evidence suggests a link between PD and gastrointestinal dysfunction. Constipation is frequently observed years prior to development of motor dysfunction in PD, and people with inflammatory bowel disease (IBD) are more likely to develop PD. Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) account for approximately 1% of all PD cases and are associated with increased risk for IBD. Among them, LRRK2 Gly2019Ser (G2019S), located within the kinase domain, is the most common PD-associated mutation and increases kinase activity. It is unknown how LRRK2 mutation affects susceptibility to intestinal inflammation or pathogenesis of PD. Using single cell RNA sequencing (scRNAseq), we demonstrate that LRRK2 G2019S mutation promotes a dysregulated gene profile, especially within neutrophil, monocyte and {gamma}{delta} T cell populations, following Citrobacter rodentium infection in mice. Transcriptionally, LRRK2 G2019S neutrophils have a greater pro- inflammatory type I and II IFN response compared to those of WT mice. This is accompanied by an increase in neutrophil numbers in the lamina propria in LRRK2 G2019S mice. We also uncover cell-intrinsic functional defects in LRRK2 G2019S neutrophils, including increased chemotaxis, degranulation and neutrophil extracellular traps (NETosis) formation. Increased neutrophil infiltration is associated with an upregulation in Th17 immune responses, which may together contribute to the observed increase in colon pathology during infection. These findings increase our understanding of the role of PD-associated genes in immune cells and their contribution to immune dysregulation. Understanding the early perturbations driven by the LRRK2 G2019S mutation in gastrointestinal pathology may facilitate the development of biomarkers for early diagnosis and intervention in PD.

immunology↗

bioRxiv2024

A type 1 immune-stromal cell network mediates disease tolerance and barrier protection against intestinal infection

Type 1 immunity mediates host defense through pathogen elimination, but whether this pathway also impacts tissue function is unknown. Here we demonstrate that rapid induction of IFN{gamma} signaling coordinates a multi-cellular response that is critical to limit tissue damage and maintain gut motility following infection of mice with a tissue-invasive helminth. IFN{gamma} production is initiated by antigen-independent activation of lamina propria CD8+ T cells following MyD88-dependent recognition of the microbiota during helminth-induced barrier invasion. IFN{gamma} acted directly on intestinal stromal cells to recruit neutrophils that limited parasite-induced tissue injury. IFN{gamma} sensing also limited the expansion of smooth muscle actin-expressing cells to prevent pathological gut dysmotility. Importantly, this tissue-protective response had limited impact on parasite burden, indicating that IFN{gamma} supports a disease tolerance defense strategy. Our results have important implications for managing the pathophysiological sequelae of post-infectious gut dysfunction and chronic inflammatory diseases associated with stromal remodelling. HIGHLIGHTSO_LIType 1 immunity is required for disease tolerance to tissue-invasive infection. C_LIO_LIGut-resident CD8+ T cells produce IFN{gamma} in an antigen-independent, yet microbiota-dependent manner. C_LIO_LIIFN{gamma} signaling recruits neutrophils in a cell-extrinsic manner to limit helminth-induced tissue injury. C_LIO_LIDirect sensing of IFN{gamma} by intestinal stroma is essential to limit tissue damage and maintain gut motility during infection. C_LI

immunology↗

bioRxiv2023

Gut microbiota promotes pain in fibromyalgia

Fibromyalgia is a chronic syndrome characterized by widespread pain in the absence of evident tissue injury or pathology, making it one of the most mysterious chronic pain conditions. Despite affecting 2-4% of the population, primarily women1, the cause and underlying mechanisms of fibromyalgia remain elusive, and effective targeted treatments are currently unavailable. The gut microbiota of women with fibromyalgia differs from healthy controls2,3. However, it is unknown whether changes in gut microbiota have a causal role in mediating pain and other symptoms of fibromyalgia. Here, we show that fecal microbiota transplantation (FMT) from individuals with fibromyalgia, but not from healthy controls, into germ-free mice induces persistent pain hypersensitivity. FMT from fibromyalgia patients led to a reduction in intraepidermal nerve fiber density and alterations in the peripheral immune profile, and induced activation of spinal microglia, which contributed to the development of pain in mice. Notably, the pain hypersensitivity in mice that were administered microbiota from fibromyalgia patients resolved after FMT from healthy controls. Consistent with these findings, an open-label pilot study showed that transplanting microbiota from healthy individuals to humans with fibromyalgia alleviated pain and reduced overall symptom severity. Thus, altered gut microbiota has a causal role in fibromyalgia pain, highlighting it as a promising target for therapeutic interventions.

neuroscience↗

bioRxiv2023

The bioactive dietary polyphenol preparation alleviates depression and anxiety-like behaviors by modulating the regional heterogeneity of microglia morphology.

ScopeThe goal of this study is to investigate the effects of a bioactive dietary polyphenol preparation (BDPP), which is made up of grape-derived polyphenols, on microglial responses, as well as the underlying molecular mechanisms in depression and anxiety-like behaviors. Methods and resultsWe find that treatment with BDPP significantly decreased depression-like and anxiety-like behaviors induced by chronic stress in mice, while leaving their locomotor activity unaffected. We also find that BDPP treatment reversed microglia activation in the amygdala and hippocampal formation, regions of the brain involved in emotional regulation, from an amoeboid shape to ramified shape. Additionally, BDPP treatment modulates the release of pro-inflammatory cytokines such as interleukin-6 via high mobility box 1 protein and the receptor for advanced glycation end products (HMGB1-RAGE) signaling pathway in activated microglia induced by chronic stress. ConclusionOur findings suggest regional heterogeneity in microglial responses following chronic stress in subregions of the corticolimbic circuit. Specifically, activation of the immune-inflammatory HMGB1-RAGE pathway might provide a new avenue for therapeutic intervention in stress-induced anxiety- and depression-like behavior, using bioactive and bioavailable polyphenols.

neuroscience↗

bioRxiv2021

Direct reprogramming of the intestinal epithelium by parasitic helminths subverts type 2 immunity

Enteric helminths form intimate physical connections with the intestinal epithelium, yet their ability to directly alter epithelial stem cell fate has not been resolved. Here we demonstrate that infection of mice with the symbiotic parasite Heligmosomoides polygyrus bakeri (Hbp), reprograms the intestinal epithelium into a fetal-like state marked by the emergence of Clusterin-expressing revival stem cells (revSCs). Organoid-based studies using parasite-derived excretory/secretory products reveal that Hpb-mediated revSC generation occurs independent of host-derived immune signals and inhibits type 2 cytokine-driven differentiation of secretory epithelial lineages that promote their expulsion. Reciprocally, type 2 cytokine signals limit revSC differentiation and, consequently, Hpb fitness indicating that helminths compete with their host for control of the intestinal stem cell niche to promote continuation of their life cycle.

immunology↗

bioRxiv2021

Synthesis and characterization of peptide conjugated human serum albumin nanoparticles for targeted cardiac uptake and drug delivery.

Congestive heart failure, a prominent cardiovascular disease results primarily from myocardial infarction or ischemia. Milrinone (MRN), a widely used clinical drug for heart failure, improves myocardial contractility and cardiac function through its inotropic and vasodilatory effects. However, lacking target specificty, it exhibits low bioavailability and lower body retention time. Therefore, in this study, angiotensin II (AT1) peptide conjugated human serum albumin nanoparticles (AT1-HSA-MRN-NPs) have been synthesized for targeted delivery of MRN to the myocardium, overexpressing AT1 receptors under heart failure. The NPs were surface functionalized through a covalent conjugation reaction between HSA and AT1. Nanoparticle size was 215.2{+/-}4.7 nm and zeta potential -28.8{+/-}2.7 mV and cumulative release of MRN was [~]72% over 24 hrs. The intracellular uptake of nanoparticles and cell viability was studied in H9c2 cells treated with AT1-MRN-HSA-NPs vs the control non-targeted drug, MRN Lactate under normal, hypoxic and hypertrophic conditions. The uptake of AT1-HSA-MRN-NPs in H9c2 cells was significantly higher as compared to non-targeted nanoparticles, and the viability of H9c2 cells treated with AT1-MRN-HSA-NPs vs MRN Lactate was 73.4{+/-}1.4% vs 44.9{+/-}1.4%, respectively. Therefore, AT1-HSA-MRN-NPs are safe for in vivo use and exhibit superior targeting and drug delivery characteristics for treatment of heart failure.

bioengineering↗