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Biology subjects

Grivennikov, S. I.

Publications and source records attributed to Grivennikov, S. I..

2 recordsLinked to original sources

IL-17RC signaling connects intestinal microbiota and neuroimmune interactions in atherosclerosis

While dysbiosis and inflammation were previously implicated in cardiovascular diseases, the circuits of how microbiota drives distant perivascular innervation, neuroinflammation and atherosclerosis remains unknown. Here, we report that IL-17RC signaling in intestine protects from atherosclerosis controlling intestinal barrier and microbiota, and loss of IL-17RC in intestinal epithelial cells alters microbiota, enhances perivascular innervation and aortic inflammation, augmenting the disease. Neuronal outgrowth is functionally dependent on microbiota and is essential for neuroinflammation and augmentation of atherosclerosis as chemical denervation reduces inflammation, macrophage activation and disease progression. Microbiota-dependent IL-17A producing {gamma}{delta} T cells accumulate in aorta to promote neuronal outgrowth and activation that can be reversed by {gamma}{delta} T cell blockade. Perivascular neuron activation is further dependent on cell autonomous IL-17 signaling as IL-17RC ablation in sympathetic neurons protected mice from microbiota-driven atherosclerosis. Together, our data illuminate how intestinal cytokine signaling distantly restrains neuroimmune interactions in aorta and uncovers a novel link between IL-17 signaling, microbiota, perivascular innervation and neuroimmune pro-inflammatory crosstalk instrumental for atherosclerosis progression. SummaryIL-17RC signaling regulates intestinal dysbiosis and perivascular neuronal outgrowth that modulates inflammation in atherosclerosis.

immunology↗

IL-27R signaling serves as immunological checkpoint for NK cells to promote hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of liver cancer with poor survival and limited therapeutic options. HCC has different etiologies, typically associated with viral or carcinogenic insults or fatty liver disease and underlying chronic inflammation presents as a major unifying mechanism for tumor promotion. On the other hand, mechanisms of how inflammatory response can regulate anti-cancer immunity in HCC remain incompletely understood. Interleukin (IL)-27 receptor signaling plays an anti-inflammatory role in a variety of infectious and chronic inflammatory diseases. Here, using genetic and pharmacological approaches we found that IL-27 receptor (IL-27R) signaling promotes HCC development in vivo. Genetic loss of IL-27R suppressed HCC development in both toxin/carcinogen-induced diethylnitrosamine (DEN) and non-alcoholic steatohepatitis (NASH)-driven models. Elevated expression of IL-27RA rendered poor prognosis to HCC patients. Mechanistically, the pro-tumorigenic effect was mediated by immunoregulatory role of IL-27R signaling within the tumor microenvironment, particularly the suppression of Natural killer (NK) cells. IL-27R ablation enhanced the accumulation and activation of cytotoxic NK cells during acute liver injury and in HCC tumors, while depletion of NK cells abrogated the effect of genetic IL-27R disruption. Taken together, our data suggest an unexpected role of IL-27R signaling as a novel immunological checkpoint regulating NK cell activity and promoting development of HCC of different etiologies.

immunology↗