RESUMEN

Intestinal permeability and bacterial translocation are increased in obesity and metabolic syndrome (MS). ILC3 cells contribute to the integrity of intestinal epithelium by producing IL-22 via IL-1ß and IL-23. This study investigates the role of IL-1R1 in inducing ILC3 cells and conferring protection during obesity and MS. For this purpose, C57BL/6 wild-type (WT) and IL-1R1-deficient mice were fed a standard diet (SD) or high-fat diet (HFD) for 16 weeks. Weight and blood glucose levels were monitored, and adipose tissue and blood samples were collected to evaluate obesity and metabolic parameters. The small intestine was collected to assess immunological and junction protein parameters through flow cytometry and RT-PCR, respectively. The intestinal permeability was analyzed using the FITC-dextran assay. The composition of the gut microbiota was also analyzed by qPCR. We found that IL-1R1 deficiency exacerbates MS in HFD-fed mice, increasing body fat and promoting glucose intolerance. A worsening of MS in IL-1R1-deficient mice was associated with a reduction in the ILC3 population in the small intestine. In addition, we found decreased IL-22 expression, increased intestinal permeability and bacterial translocation to the visceral adipose tissue of these mice compared to WT mice. Thus, the IL-1R1 receptor plays a critical role in controlling intestinal homeostasis and obesity-induced MS, possibly through the differentiation or activation of IL-22-secreting ILC3s.

RESUMEN

Innate lymphoid cells (ILCs) are classified into distinct subsets termed ILC1, ILC2, and ILC3 cells. The existing literature lacks evidence identifying ILCs and their subsets in the human thymus but already demonstrates that they can exert several functions in regulating immune responses. Furthermore, it was already described that IgG's repertoires could modulate lymphocytes' maturation in the human thymus. Here we aimed to identify ILCs subsets in the human thymus and provide insight into the possible modulatory effect of purified IgG on these cells. Thymic tissues were obtained from 12 infants without an allergic background (non-atopic), and a literature-based peripheral ILCs staining protocol was used. Purified IgG was obtained from non-atopic individuals (n-At), atopic individuals reactive to allergens non-related to dust mites (nr-At), and atopic individuals reactive to the mite Dermatophagoides pteronyssinus (Derp-At). As with all tissues in which they have already been detected, thymic ILCs are rare, but we could detect viable ILCs in all tested tissues, which did not occur with the ILC1 subset. ILC2 and ILC3 NKp44+ subsets could be detected in all evaluated thymus, but ILC3 NKp44- subset could not. Next, we observed that Derp-At IgG could induce the expression of ILC2 phenotype, higher levels of IL-13, and lower levels of IL-4 when compared to IgG purified from non-atopic or non-related atopic (atopic to allergens excluding dust mites) individuals. These results contribute to the elucidation of human thymic ILCs and corroborate emerging evidence about IgG's premature effect on allergy development-related human lymphocytes' modulation.

RESUMEN

PURPOSE: Type 3 innate lymphocytes (ILC3s) are reported to be involved in lung cancer, possibly by producing interleukin-22 (IL-22). However, whether ILC3s and their secreted IL-22 molecules contribute to the pathogenesis of pancreatic cancer (PC) remains unclear. To this end, in this study, we investigated the effects and possible mechanisms of ILC3s on PC pathogenesis. METHOD: The IL-22 and IL-2i2R levels and the ILC3s' frequency in cancer tissues from PC patients and in peripheral blood from PC patients and healthy controls were analyzed by flow cytometry, immunochemistry, or immunofluorescence. The effects of IL-22-induced AKT signaling on the proliferation, invasion, and migration of PC cells were examined by co-culturing PC cell lines with ILC3s isolated from PC tissues, with or without the addition of neutralizing IL-22 antibody, IL-22R antibody or AKT inhibitor. RESULTS: Our results showed that IL-22 and ILC3s were significantly upregulated in the PBMCs and cancer tissues of PC patients, and the IL-22R level was increased in PC cells. The increased frequency of ILC3s was positively correlated with the clinical features of PC patients. Co-culture experiments indicated that ILC3s promoted the proliferation, invasion, and migration of PC cell lines by secreting IL-22 to activate AKT signaling because IL-22/IL-22R or AKT blockage markedly counteracted such effects on PC cells. CONCLUSION: Our data demonstrated that ILC3s may promote PC pathogenesis through IL-22/IL-22R-AKT signaling, suggesting a potential intervention target for PC treatment in the future.

Asunto(s)

Inmunidad Innata/inmunología , Interleucinas/fisiología , Linfocitos/fisiología , Neoplasias Pancreáticas/patología , Proteínas Proto-Oncogénicas c-akt/fisiología , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Femenino , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Receptores de Interleucina/fisiología , Transducción de Señal/fisiología , Interleucina-22

RESUMEN

Excess intake of sodium is often associated with high risk for cardiovascular disease. More recently, some studies on the effects of high-salt diets (HSDs) have also demonstrated that they are able to activate Th17 cells and increase severity of autoimmune diseases. The purpose of the present study was to evaluate the effects of a diet supplemented with NaCl in the colonic mucosa at steady state and during inflammation. We showed that consumption of HSD by mice triggered a gut inflammatory reaction associated with IL-23 production, recruitment of neutrophils, and increased frequency of the IL-17-producing type 3 innate lymphoid cells (ILC3) in the colon. Moreover, gut inflammation was not observed in IL-17-/- mice but it was present, although at lower grade, in RAG-/- mice suggesting that the inflammatory effects of HSD was dependent on IL-17 but only partially on Th17 cells. Expression of SGK1, a kinase involved in sodium homeostasis, increased 90 min after ingestion of 50% NaCl solution and decreased 3 weeks after HSD consumption. Colitis induced by oral administration of either dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid was exacerbated by HSD consumption and this effect was associated with increased frequencies of RORγt+ CD4+ T cells and neutrophils in the colon. Therefore, our results demonstrated that consumption of HSD per se triggered a histologically detectable inflammation in the colon and also exacerbated chemically induced models of colitis in mice by a mechanism dependent on IL-17 production most likely by both ILC3 and Th17 cells.