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Mucosal-associated invariant T (MAIT) cells represent an abundant innate-like T cell subtype in the human liver. MAIT cells are assigned crucial roles in regulating immunity and inflammation, yet their role in liver cancer remains elusive. Here, we present a MAIT cell-centered profiling of hepatocellular carcinoma (HCC) using scRNA-seq, flow cytometry, and co-detection by indexing (CODEX) imaging of paired patient samples. These analyses highlight the heterogeneity and dysfunctionality of MAIT cells in HCC and their defective capacity to infiltrate liver tumors. Machine-learning tools were used to dissect the spatial cellular interaction network within the MAIT cell neighborhood. Co-localization in the adjacent liver and interaction between niche-occupying CSF1R+PD-L1+ tumor-associated macrophages (TAMs) and MAIT cells was identified as a key regulatory element of MAIT cell dysfunction. Perturbation of this cell-cell interaction in ex vivo co-culture studies using patient samples and murine models reinvigorated MAIT cell cytotoxicity. These studies suggest that aPD-1/aPD-L1 therapies target MAIT cells in HCC patients.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Células T Invariantes Associadas à Mucosa , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/patologia , Células T Invariantes Associadas à Mucosa/imunologia , Células T Invariantes Associadas à Mucosa/patologia , Macrófagos Associados a TumorRESUMO
Despite clinical advances, chemotherapy largely fails in metastatic cancers. Commensal bacteria can indicate chemotherapy efficacy. In a recent issue of Nature, Tintelnot et al.1 demonstrate that bacterial metabolite 3-IAA amplifies chemotherapy outcomes via autophagy pathways in metastatic pancreatic ductal adenocarcinoma.
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Adenocarcinoma , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologiaRESUMO
The gut microbiome is an important modulator of the host immune system. In this study, we found that altering the gut microbiome by oral vancomycin increases liver invariant NKT (iNKT) cell function. Enhanced iNKT cytokine production and activation marker expression were observed in vancomycin-treated mice following both Ag-specific and Ag-independent in vivo iNKT stimulations, with a more prominent effect in the liver than in the spleen. Fecal transplantation studies demonstrated that the iNKT functional regulation is mediated by altering the gut microbiome but uncoupled from the modulation of iNKT cell population size. Interestingly, when stimulated in vitro, iNKT cells from vancomycin-treated mice did not show increased activation, suggesting an indirect regulation. iNKT cells expressed high levels of IL-18 receptor, and vancomycin increased the expression of IL-18 in the liver. Blocking IL-18 by neutralizing Ab or using genetically deficient mice attenuated the enhanced iNKT activation. Liver macrophages were identified as a major source of IL-18. General macrophage depletion by clodronate abolished this iNKT activation. Using anti-CSF-1R depletion or LyzCrexCSF-1RLsL-DTR mice identified CSF-1R+ macrophages as a critical modulator of iNKT function. Vancomycin treatment had no effect on iNKT cell function in vivo in IL-18 knockout macrophage reconstituted mice. Together, our results demonstrate that the gut microbiome controls liver iNKT function via regulating CSF-1R+ macrophages to produce IL-18.
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Microbioma Gastrointestinal , Camundongos , Animais , Interleucina-18 , Vancomicina/farmacologia , Macrófagos , Fígado , Camundongos Knockout , Receptores Proteína Tirosina QuinasesRESUMO
OBJECTIVE: Liver metastases are often resistant to immune checkpoint inhibitor therapy (ICI) and portend a worse prognosis compared with metastases to other locations. Regulatory T cells (Tregs) are one of several immunosuppressive cells implicated in ICI resistance of liver tumours, but the role played by Tregs residing within the liver surrounding a tumour is unknown. DESIGN: Flow cytometry and single-cell RNA sequencing were used to characterise hepatic Tregs before and after ICI therapy. RESULTS: We found that the murine liver houses a Treg population that, unlike those found in other organs, is both highly proliferative and apoptotic at baseline. On administration of αPD-1, αPD-L1 or αCTLA4, the liver Treg population doubled regardless of the presence of an intrahepatic tumour. Remarkably, this change was not due to the preferential expansion of the subpopulation of Tregs that express PD-1. Instead, a subpopulation of CD29+ (Itgb1, integrin ß1) Tregs, that were highly proliferative at baseline, doubled its size in response to αPD-1. Partial and full depletion of Tregs identified CD29+ Tregs as the prominent niche-filling subpopulation in the liver, and CD29+ Tregs demonstrated enhanced suppression in vitro when derived from the liver but not the spleen. We identified IL2 as a critical modulator of both CD29+ and CD29- hepatic Tregs, but expansion of the liver Treg population with αPD-1 driven by CD29+ Tregs was in part IL2-independent. CONCLUSION: We propose that CD29+ Tregs constitute a unique subpopulation of hepatic Tregs that are primed to respond to ICI agents and mediate resistance.
Assuntos
Neoplasias Hepáticas , Linfócitos T Reguladores , Animais , Camundongos , Interleucina-2 , Integrina beta1 , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologiaRESUMO
Nonalcoholic fatty liver disease (NAFLD) is a chronic condition affecting one quarter of the global population. Although primarily linked to obesity and metabolic syndrome, undernutrition and the altered (dysbiotic) gut microbiome influence NAFLD progression. Both undernutrition and NAFLD prevalence are predicted to considerably increase, but how the undernourished gut microbiome contributes to hepatic pathophysiology remains far less studied. Here, we present undernutrition conditions with fatty liver features, including kwashiorkor and micronutrient deficiency. We then review the gut microbiota-liver axis, highlighting key pathways linked to NAFLD progression within both overnutrition and undernutrition. To conclude, we identify challenges and collaborative possibilities of emerging multiomic research addressing the pathology and treatment of undernourished NAFLD.
Assuntos
Microbioma Gastrointestinal , Desnutrição , Hepatopatia Gordurosa não Alcoólica , Disbiose/metabolismo , Microbioma Gastrointestinal/fisiologia , Humanos , Fígado/patologia , Desnutrição/epidemiologia , Hepatopatia Gordurosa não Alcoólica/patologiaRESUMO
Fecal-oral contamination promotes malnutrition pathology. Lasting consequences of early life malnutrition include cognitive impairment, but the underlying pathology and influence of gut microbes remain largely unknown. Here, we utilize an established murine model combining malnutrition and iterative exposure to fecal commensals (MAL-BG). The MAL-BG model was analyzed in comparison to malnourished (MAL mice) and healthy (CON mice) controls. Malnourished mice display poor spatial memory and learning plasticity, as well as altered microglia, non-neuronal CNS cells that regulate neuroimmune responses and brain plasticity. Chronic fecal-oral exposures shaped microglial morphology and transcriptional profile, promoting phagocytic features in MAL-BG mice. Unexpectedly, these changes occurred independently from significant cytokine-induced inflammation or blood-brain barrier (BBB) disruption, key gut-brain pathways. Metabolomic profiling of the MAL-BG cortex revealed altered polyunsaturated fatty acid (PUFA) profiles and systemic lipoxidative stress. In contrast, supplementation with an ω3 PUFA/antioxidant-associated diet (PAO) mitigated cognitive deficits within the MAL-BG model. These findings provide valued insight into the malnourished gut microbiota-brain axis, highlighting PUFA metabolism as a potential therapeutic target.
Assuntos
Microbioma Gastrointestinal , Desnutrição , Animais , Cognição , Microbioma Gastrointestinal/fisiologia , Desnutrição/complicações , Camundongos , Camundongos Endogâmicos C57BL , MicrogliaRESUMO
BACKGROUND & AIMS: Non-alcoholic steatohepatitis (NASH) represents the fastest growing underlying cause of hepatocellular carcinoma (HCC) and has been shown to impact immune effector cell function. The standard of care for the treatment of advanced HCC is immune checkpoint inhibitor (ICI) therapy, yet NASH may negatively affect the efficacy of ICI therapy in HCC. The immunologic mechanisms underlying the impact of NASH on ICI therapy remain unclear. METHODS: Herein, using multiple murine NASH models, we analysed the influence of NASH on the CD8+ T-cell-dependent anti-PD-1 responses against liver cancer. We characterised CD8+ T cells' transcriptomic, functional, and motility changes in mice receiving a normal diet (ND) or a NASH diet. RESULTS: NASH blunted the effect of anti-PD-1 therapy against liver cancers in multiple murine models. NASH caused a proinflammatory phenotypic change of hepatic CD8+ T cells. Transcriptomic analysis revealed changes related to NASH-dependent impairment of hepatic CD8+ T-cell metabolism. In vivo imaging analysis showed reduced motility of intratumoural CD8+ T cells. Metformin treatment rescued the efficacy of anti-PD-1 therapy against liver tumours in NASH. CONCLUSIONS: We discovered that CD8+ T-cell metabolism is critically altered in the context of NASH-related liver cancer, impacting the effectiveness of ICI therapy - a finding which has therapeutic implications in patients with NASH-related liver cancer. LAY SUMMARY: Non-alcoholic steatohepatitis represents the fastest growing cause of hepatocellular carcinoma. It is also associated with reduced efficacy of immunotherapy, which is the standard of care for advanced hepatocellular carcinoma. Herein, we show that non-alcoholic steatohepatitis is associated with impaired motility, metabolic function, and response to anti-PD-1 treatment in hepatic CD8+ T cells, which can be rescued by metformin treatment.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Metformina , Hepatopatia Gordurosa não Alcoólica , Animais , Linfócitos T CD8-Positivos/metabolismo , Carcinoma Hepatocelular/metabolismo , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Fígado/patologia , Neoplasias Hepáticas/etiologia , Metformina/farmacologia , Metformina/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismoRESUMO
Does exploration of the gut microbiota-brain axis expand our understanding of what it means to be human? Recognition and conceptualization of a gut microbiota-brain axis challenges our study of the nervous system. Here, integrating gut microbiota-brain research into the metaorganism model is proposed. The metaorganism-an expanded, dynamic unit comprising the host and commensal organisms-asserts a radical blurring between man and microbe. The metaorganism nervous system interacts with the exterior world through microbial-colored lenses. Ongoing studies have reported that gut microbes contribute to brain function and pathologies, even shaping higher neurological functions. How will continued collaborative efforts (e.g., between neurobiology and microbiology), including partnerships with the arts (e.g., philosophy), contribute to the knowledge of microbe-to-mind interactions? While this is not a systemic review, this nascent field is briefly described, highlighting ongoing challenges and recommendations for emerging gut microbiota-brain research. Also see the video abstract here https://youtu.be/lP9gOW8StXg.
Assuntos
Encéfalo/fisiologia , Microbioma Gastrointestinal , Animais , HumanosRESUMO
Almost half the cells and 1% of the unique genes found in our bodies are human, the rest are from microbes, predominantly bacteria, archaea, fungi, and viruses. These microorganisms collectively form the human microbiota, with most colonizing the gut. Recent technological advances, open access data libraries, and application of high-throughput sequencing have allowed these microbes to be identified and their contribution to neurological health to be examined. Emerging evidence links perturbations in the gut microbiota to neurological disease, including disease risk, activity, and progression. This review provides an overview of the recent advances in microbiome research in relation to neuro(auto)immune and neurodegenerative conditions affecting humans, such as multiple sclerosis, neuromyelitis optica spectrum disorders, Parkinson disease, Alzheimer disease, Huntington disease, and amyotrophic lateral sclerosis. Study design and terminology used in this rapidly evolving, highly multidisciplinary field are summarized to empower and engage the neurology community in this "newly discovered organ." Ann Neurol 2017;81:369-382.
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Doenças Autoimunes Desmielinizantes do Sistema Nervoso Central , Microbioma Gastrointestinal/fisiologia , Doenças Neurodegenerativas , Animais , Doenças Autoimunes Desmielinizantes do Sistema Nervoso Central/etiologia , Doenças Autoimunes Desmielinizantes do Sistema Nervoso Central/imunologia , Doenças Autoimunes Desmielinizantes do Sistema Nervoso Central/microbiologia , Humanos , Doenças Neurodegenerativas/etiologia , Doenças Neurodegenerativas/imunologia , Doenças Neurodegenerativas/microbiologiaRESUMO
The concept of a gut microbiota-brain axis has emerged to describe the complex and continuous signalling between the gut microbiota and host nervous system. This review examines key microbial-derived neuromodulators and structural components that comprise the gut microbiota-brain axis. To conclude, we briefly identify current challenges in gut microbiota-brain research and suggest a framework to characterize these interactions. Here, we propose five emerging hallmarks of the gut microbiota-brain axis: (i) Indistinguishability, (ii) Emergence, (iii) Bidirectional Signalling, (iv) Critical Window Fluidity and (5) Neural Homeostasis.
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Encéfalo/microbiologia , Microbioma Gastrointestinal/genética , Sistema Nervoso/microbiologia , Trato Gastrointestinal/microbiologia , Humanos , Transdução de SinaisRESUMO
Backgrounds & Aims: The efficacy of immune checkpoint inhibitor (ICI) therapy for liver cancer remains limited. As the hypoxic liver environment regulates adenosine signaling, we tested the efficacy of adenosine A2a receptor (A2aR) inhibition in combination with ICI treatment in murine models of liver cancer. Methods: RNA expression related to the adenosine pathway was analyzed from public databases. Peripheral blood mononuclear cells of 13 patients with hepatocellular carcinoma (HCC) were examined by flow cytometry. The following murine cell lines were used: SB-1, RIL175, and Hep55.1c (liver cancer), CT26 (colon cancer), and B16-F10 (melanoma). C57BL/6 and BALB/c mice were used for orthotopic tumor models and were treated with SCH58261, an A2aR inhibitor, in combination with anti-PD1 therapy. Results: RNA expression of ADORA2A in tumor tissues derived from patients with HCC was higher than in tissues from other cancer types. A2aR+ T cells in peripheral blood from patients with HCC were highly proliferative after immunotherapy. Likewise, in an orthotopic murine model, A2aR expression on T cells increased following anti-PD1 treatment, and the expression of A2aR on T cells increased more in tumor-bearing mice compared with tumor-free mice. The combination of SCH58261 and anti-PD1 led to activation of T cells and reductions in tumor size in orthotopic liver cancer models. In contrast, SCH58261 monotherapy was ineffective in orthotopic liver cancer models and the combination was ineffective in the subcutaneous tumor models tested. CD4+ T-cell depletion attenuated the efficacy of the combination therapy. Conclusion: A2aR inhibition and anti-PD1 therapy had a synergistic anti-tumor effect in murine liver cancer models. Impact and implications: Adenosine A2a receptor (A2aR)-expressing T cells in the liver increased in tumor-bearing mice and after anti-PD1 treatment. The combination of an A2aR inhibitor and anti-PD1 treatment had potent anti-tumor effects in two murine models of orthotopic liver cancer. Adenosine A2a receptor blockade promotes immunotherapy efficacy in murine models, highlighting putative clinical benefits for advanced stage liver cancer patients.
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Liver cancer ranks amongst the deadliest cancers. Nerves have emerged as an understudied regulator of tumor progression. The parasympathetic vagus nerve influences systemic immunity via acetylcholine (ACh). Whether cholinergic neuroimmune interactions influence hepatocellular carcinoma (HCC) remains uncertain. Liver denervation via hepatic vagotomy (HV) significantly reduced liver tumor burden, while pharmacological enhancement of parasympathetic tone promoted tumor growth. Cholinergic disruption in Rag1KO mice revealed that cholinergic regulation requires adaptive immunity. Further scRNA-seq and in vitro studies indicated that vagal ACh dampens CD8+ T cell activity via muscarinic ACh receptor (AChR) CHRM3. Depletion of CD8+ T cells abrogated HV outcomes and selective deletion of Chrm3 on CD8 + T cells inhibited liver tumor growth. Beyond tumor-specific outcomes, vagotomy improved cancer-associated fatigue and anxiety-like behavior. As microbiota transplantation from HCC donors was sufficient to impair behavior, we investigated putative microbiota-neuroimmune crosstalk. Tumor, rather than vagotomy, robustly altered fecal bacterial composition, increasing Desulfovibrionales and Clostridial taxa. Strikingly, in tumor-free mice, vagotomy permitted HCC-associated microbiota to activate hepatic CD8+ T cells. These findings reveal that gut bacteria influence behavior and liver anti-tumor immunity via a dynamic and pharmaceutically targetable, vagus-liver axis.
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BACKGROUND: Parkinson's disease (PD) is a multi-system disorder consisting of not only classic motor symptoms but also a variety of non-motor symptoms including gastrointestinal (GI) dysfunction and mood disorders. The gut microbiota has been suggested to play a role in modulating PD motor and non-motor features, although the causality and mechanisms behind these proposed interactions remains largely understudied. OBJECTIVE: In this study, we aimed to provide in-depth characterization of an established mouse model of PD (transgenic (TG) SNCA A53T) and experimentally address how changes to the gut microbiota impact the PD-like phenotype. METHODS: We profiled the PD-like phenotype of transgenic mice through a panel of motor, GI, and behavioral tests. We then investigated how antibiotic treatment or gut microbial community transfer (via cohousing with wild-type mice) impacted the PD-like phenotype. RESULTS: We found that this mouse model demonstrated early (6 weeks of age) motor symptoms when compared to a wild-type control mouse strain. Transgenic mice also exhibited early GI dysfunction, as well as behavioral alterations, including reduced anxiety-like behavior, and increased depression-like and apathy-like behavior. Compared to wild-type mice, the transgenic fecal microbiota was less diverse and compositionally distinct. Interestingly, drastic alterations to the gut microbiota, through antibiotic treatment or cohousing with wild-type mice, had a minimal effect on the motor, GI, and behavioral phenotype of transgenic mice. CONCLUSION: We concluded that this mouse model effectively recapitulates motor and non-motor features of PD; however, the gut microbiota appears to exhibit a minor impact on the pathophysiology of this PD model.
Assuntos
Gastroenteropatias , Microbioma Gastrointestinal , Doença de Parkinson , Animais , Antibacterianos , Modelos Animais de Doenças , Microbioma Gastrointestinal/fisiologia , Camundongos , Camundongos Transgênicos , FenótipoRESUMO
Immunoglobulin (Ig) A controls host-microbial homeostasis in the gut. IgA recognition of beneficial bacteria is decreased in acutely undernourished children, but the factors driving these changes in IgA targeting are unknown. Child undernutrition is a global health challenge that is exacerbated by poor sanitation and intestinal inflammation. To understand how nutrition impacts immune-microbe interactions, we used a mouse model of undernutrition with or without fecal-oral exposure and assessed IgA-bacterial targeting from weaning to adulthood. In contrast to healthy control mice, undernourished mice fail to develop IgA recognition of intestinal Lactobacillus. Glycan-mediated interactions between Lactobacillus and host antibodies are lost in undernourished mice due to rapid bacterial adaptation. Lactobacillus adaptations occur in direct response to nutritional pressure, independently of host IgA, and are associated with reduced mucosal colonization and with bacterial mutations in carbohydrate processing genes. Together these data indicate that diet-driven bacterial adaptations shape IgA recognition in the gut.
Assuntos
Bactérias/metabolismo , Microbioma Gastrointestinal/imunologia , Interações entre Hospedeiro e Microrganismos/imunologia , Imunoglobulina A/imunologia , Estado Nutricional , Simbiose/fisiologia , Adulto , Animais , Bactérias/genética , Proteínas de Ligação a DNA/genética , Dieta , Fezes/microbiologia , Homeostase , Humanos , Inflamação , Intestino Delgado , Lactobacillus/fisiologia , Camundongos , Camundongos Knockout , Polissacarídeos , Açúcares/metabolismoRESUMO
Docosahexaenoic acid (DHA) is an essential fatty acid modulating key nervous system functions, including neuroinflammation, and regulation of pre- and postsynaptic membrane formation. DHA concentration decreases in the lumbar spinal cord (LSC) of amyotrophic lateral sclerosis (ALS) patients and murine preclinical models. Using a dietary supplementation, we increased DHA levels (2% mean increase, p < 0.01) in the LSC of the familial ALS murine model B6SJL-Tg(SOD1*G93A)1Gur/J. This DHA-enriched diet significantly increases male mouse survival by 7% (average 10 days over 130 days of life expectancy), and delays motor dysfunction (based on stride length) and transgene-associated weight loss (p < 0.01). DHA supplementation led to an increased anti-inflammatory fatty acid profile (ca 30%, p < 0.01) and a lower concentration of circulating proinflammatory cytokine TNF-α (p < 0.001 in males). Furthermore, although DHA-treated mice did not exhibit generally decreased protein oxidative markers (glutamic and aminoadipic semialdehydes, carboxyethyllysine, carboxymethyllysine, and malondialdehydelysine), dietary intake of DHA reduced immunoreactivity towards DNA oxidative damage markers (8-oxo-dG) in the LSC. In vitro we demonstrate that DHA and α-tocopherol addition to a model of motor neuron demise (neonatal rat organotypic spinal cord model under chronic excitotoxicity) also preserves motor neuron number, in comparison with untreated spinal cords. Also, beneficial effects on cell viability were evidenced for the motor neuron cell line NSC-34 in front of H2O2 insult (p < 0.001). Globally we show a sex-specific benefit of dietary DHA supplementation in the G93A ALS mouse model, compared with mice fed an isocaloric control or a n-3-depleted diet. These changes were associated with an increased DHA concentration in the LSC and were compatible with in vitro results showing DHA neuroprotective properties. These results suggest the need for further study on the interaction of gender-influenced biological parameters and DHA in ALS pathogenesis.
Assuntos
Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/metabolismo , Ácidos Docosa-Hexaenoicos/administração & dosagem , Animais , Suplementos Nutricionais , Modelos Animais de Doenças , Feminino , Masculino , Camundongos Transgênicos , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Estresse Oxidativo , Caracteres Sexuais , Fatores Sexuais , Medula Espinal/efeitos dos fármacosRESUMO
Diet is a critical determinant of variation in gut microbial structure and function, outweighing even host genetics1-3. Numerous microbiome studies have compared diets with divergent ingredients1-5, but the everyday practice of cooking remains understudied. Here, we show that a plant diet served raw versus cooked reshapes the murine gut microbiome, with effects attributable to improvements in starch digestibility and degradation of plant-derived compounds. Shifts in the gut microbiota modulated host energy status, applied across multiple starch-rich plants, and were detectable in humans. Thus, diet-driven host-microbial interactions depend on the food as well as its form. Because cooking is human-specific, ubiquitous and ancient6,7, our results prompt the hypothesis that humans and our microbiomes co-evolved under unique cooking-related pressures.