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Feng, T.-Y.

Publications and source records attributed to Feng, T.-Y..

5 recordsLinked to original sources

Ovarian Cancer Drives TLR5-Dependent Expansion of Myeloid Progenitors Through Systemic Dissemination of Ligands

Ovarian cancer remains the most lethal gynecologic malignancy, due in part to the establishment of a profoundly immunosuppressive tumor microenvironment (TME). While TLR5 signaling has previously been implicated in promoting myeloid cell recruitment to the ovarian TME, the upstream source of ligand and its systemic effects on hematopoiesis remain poorly understood(1,2). Here, we show that ovarian cancer disrupts gut barrier integrity, leading to systemic translocation of TLR5 ligands into the peritoneum, blood, and bone marrow. This translocation correlates with enhanced expansion of myeloid progenitors in the bone marrow of wild-type (WT) but not TLR5-deficient (TLR5 KO) mice, leading to enhanced accumulation of monocytes into the tumor microenvironment. Pharmacologic blockade of TLR5 in tumor-bearing mice alters the composition of tumor-associated myeloid populations, increasing the frequency of monocytes and CCR2-expressing macrophages In the bone marrow of tumor-bearing WT mice. In the bone marrow, blockade of TLR5 signaling led to expansion of granulocyte-monocyte progenitors (GMPs), a phenotype recapitulated in a competitive chimera model. In vitro, stimulation of WT bone marrow cells with purified TLR5 ligands led to enhanced colony formation and skewed differentiation toward granulocyte-macrophage lineages. These data reveal that chronic TLR5 signaling, driven by tumor-induced gut leakage, promotes expansion of myeloid cells within the bone marrow and is a host-intrinsic mechanism driving accumulation of immature monocytes and macrophages into the tumor microenvironment.

immunology↗

Spatially-divergent metabolic impact of experimental toxoplasmosis: immunological and microbial correlates

Maladaptive host metabolic responses to infection are emerging as major determinants of infectious disease pathogenesis. However, the factors regulating these metabolic changes within tissues remain poorly understood. In this study, we used toxoplasmosis, as a prototypical example of a disease regulated by strong type I immune responses, to assess the relative roles of local parasite burden, local tissue inflammation and the microbiome in shaping local tissue metabolism during acute and chronic infection. Toxoplasmosis is a zoonotic disease caused by the parasite Toxoplasma gondii. This protozoan infects the small intestine and then disseminates to nearly every organ in the acute stage of infection, before establishing chronic infection in the skeletal muscle, cardiac muscle and brain. We compared metabolism in eleven sampling sites in C57BL/6 mice during the acute and chronic stage of T. gondii infection. Strikingly, significant metabolic changes were observed in the large intestine and colon during chronic infection, organs not associated with T. gondii persistence. Overall, major spatial mismatches were observed between metabolic perturbation and local parasite burden for both disease stages. In contrast, a stronger association with indicators of type I immune responses was observed, indicating a tighter relationship between metabolic perturbation and local immunity, than with local parasite burden. In addition, we observed significant changes in microbiota composition with infection, and candidate microbial origins for multiple metabolites impacted by infection. These findings highlight the metabolic consequences of toxoplasmosis across different organs, and their regulators. ImportanceInflammation is a major driver of tissue perturbation. However, the signals driving these changes on a tissue-intrinsic and molecular level are poorly understood. This study evaluated tissue-specific metabolic perturbations across eleven sampling sites following systemic murine infection with the parasite Toxoplasma gondii. Results revealed relationships between differential metabolite enrichment and variables including inflammatory signals, pathogen burden and commensal microbial communities. These data will inform hypotheses about the signals driving specific metabolic adaptation in acute and chronic protozoan infection, with broader implications for infection and inflammation in general.

microbiology↗

Demonstration of chemotherapeutic mediated lymphatic changes in meningeal lymphatics in vitro, ex vivo, and in vivo

Systemic chemotherapeutics target cancer cells but are also known to impact other cells away from the tumor. Questions remain whether systemic chemotherapy crosses the blood-brain barrier and causes inflammation in the periphery that impacts the central nervous system (CNS) downstream. The meningeal lymphatics are a critical component that drain cerebrospinal fluid from the CNS to the cervical lymph nodes for immunosurveillence. To develop new tools for understanding chemotherapy-mediated effects on the meningeal lymphatics, we present two novel models that examine cellular and tissue level changes. Our in vitro tissue engineered model of a meningeal lymphatic vessel lumen, using a simple tissue culture insert system with both lymphatic endothelial and meningeal cells, examines cell disruption. Our ex vivo model culturing mouse meningeal layers probes structural changes and remodeling, correlating to an explant tissue level. To gain a holistic understanding, we compare our in vitro and ex vivo models to in vivo studies for validation and a three-tier methodology for examining the chemotherapeutic response of the meningeal lymphatics. We have demonstrated that the meningeal lymphatics can be disrupted by systemic chemotherapy but show differential responses to platinum and taxane chemotherapies, emphasizing the need for further study of off-target impacts in the CNS.

bioengineering↗

Tricarboxylic acid (TCA) cycle, sphingolipid, phosphatidylcholine metabolism is dysregulated in T. gondii infection-induced cachexia

Cachexia is a life-threatening disease characterized by chronic, inflammatory muscle wasting and systemic metabolic impairment. Despite its high prevalence, there are no efficacious therapies for cachexia. Mice chronically infected with the protozoan parasite Toxoplasma gondii represent a novel animal model recapitulating the chronic kinetics of cachexia. To understand how perturbations to metabolic tissue homeostasis influence circulating metabolite availability we used mass spectrometry analysis. Despite the significant reduction in circulating triacylglycerides, non-esterified fatty acids, and glycerol, sphingolipid long-chain bases and a subset of phosphatidylcholines (PCs) were significantly increased in the sera of mice with T. gondii infection-induced cachexia. In addition, the TCA cycle intermediates -ketoglutarate, 2-hydroxyglutarate, succinate, fumarate, and malate were highly depleted in cachectic mouse sera. Sphingolipids and their de novo synthesis precursors PCs are the major components of the mitochondrial membrane and regulate mitochondrial function consistent with a causal relationship in the energy imbalance driving T. gondii-induced chronic cachexia.

immunology↗

Reciprocal interactions between the gut microbiome and mammary tissue mast cells promote metastatic dissemination of HR+ breast tumors

Establishing commensal dysbiosis, defined as an inflammatory gut microbiome with low biodiversity, prior to breast tumor initiation, enhances early dissemination of hormone-receptor positive (HR+) mammary tumor cells. Here, we sought to define mammary tissue mediators of dysbiosis-induced tumor dissemination. We found that commensal dysbiosis increased both the frequency and profibrogenicity of mast cells in the mammary tissue, a phenotypic change that persisted after tumor implantation. Fibroblast activation and tissue remodeling associate with enhanced breast tumor metastasis. We employed pharmacological and adoptive transfer approaches to demonstrate that mammary tissue mast cells from dysbiotic animals enhances dissemination of HR+ tumor cells. Collagen levels in mammary tissues from HR+ breast cancer patients correlated with mast cell abundance, suggesting clinical relevance of mast cell-mediated fibroblast activation. Together, these data demonstrate that a gut-mast cell axis exists that induces fibroblast activation and orchestrates early dissemination of HR+ breast tumors. SignificanceOur study defines the mechanism by which an inflammatory gut microbiome facilitates HR+ breast tumor cell dissemination. We establish that gut commensal dysbiosis triggers mammary tissue mast cells to facilitate early metastatic dissemination. These findings highlight a novel gut microbiome-innate immune cell axis involved in negative breast cancer outcomes.

cancer biology↗