Sex-based differences in natural killer T cell-mediated protection against diet-induced steatohepatitis in Balb/c mice
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ABSTRACT:
SUBMITTER: Cuno-Gomiz C
PROVIDER: S-EPMC10644614 | biostudies-literature | 2023 Jan
REPOSITORIES: biostudies-literature
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Project description:Background: The association of obesity and an increased risk for severe infections and various cancer types is well-described. Natural killer (NK) cells are circulating lymphoid cells and promoters of the immune response toward viruses and malignant cells. As demonstrated in previous studies the phenotype and functionality of NK cells is impaired in obesity. So far, the majority of animal studies were exclusively performed using ad libitum feeding regimes and it remained unclear whether NK cell alterations are mediated by obesity-associated immunological changes or by direct effects of the dietary composition. Therefore, the aim of the present study was to characterize NK cells in the peripheral blood of obese-resistant BALB/c mice supplied a normal-fat diet (NFD) or high-fat diet (HFD), ad libitum or in a restrictive manner. Methods: Twenty-eight BALB/c-mice were fed a NFD or HFD either ad libitum or in a restrictive feeding regime with 90% of the mean daily diet supply of the corresponding ad libitum group (each group n = 7). Blood and visceral adipose tissue were collected for flow cytometric analysis, analysis of plasma cytokine concentrations by multiplex immunoassay and real-time RT-PCR analyses. For statistical analyses two-way ANOVA with the factors "feeding regime" and "diet" was performed followed by a post-hoc Tukey's multiple comparison test and to compare means of the four mouse groups. Results: Ad libitum-feeding of a HFD in BALB/c mice has no influence on body weight gain, visceral fat mass, plasma cytokine concentrations, immune cell populations as well as the number, frequency and phenotype of NK cells. In contrast, restrictive feeding of a HFD compared to NFD led to significantly higher body weights, visceral fat mass and plasma interferon-γ concentrations which was associated with changes in the frequencies of granulocytes and NK cell subsets as well as in the surface expression of NK cell maturation markers. Conclusion: Results demonstrate for the first time that HFD-induced alterations in NK cells are consequences of the obese associated immunological profile rather than a direct effect of the dietary composition. These data can help to clarify the increased risk for cancer and severe infections in obesity.
| S-EPMC8342926 | biostudies-literature
Project description:Natural killer (NK) cells are important antiviral effector cells and also involved in tumor clearance. NK cells express IFNAR, rendering them responsive to Type I IFNs. To evaluate Type I IFN-mediated modulation of NK cell functions, individual Type I IFNs subtypes were assessed for their ability to activate NK cells. Different Type I IFN subtypes displayed a broad range in the capacity to induce and modulate NK cell activation and degranulation, measured by CD69 and CD107a expression in response to leukemia cell line K562. When including biological sex as a variable in the analysis, transwell co-cultures of NK cells with either male- or female-derived PBMCs or pDCs stimulated with the TLR7/8 agonist CL097 showed that NK cells were more activated by CL097-stimulated cells derived from females. These sex-specific differences were linked to higher CL097-induced IFNα production by pDCs derived from females, indicating an extrinsic sex-specific effect of Type I IFNs on NK cell function. Interestingly, in addition to the extrinsic effect, we also observed NK cell-intrinsic sex differences, as female NK cells displayed higher activation levels after IFNα-stimulation and after co-culture with CL097-stimulated pDCs, suggesting higher activation of IFNα-signaling transduction in female NK cells. Taken together, the results from these studies identify both extrinsic and intrinsic sex-specific differences in Type I IFN-dependent NK cell functions, contributing to a better understanding of sex-specific differences in innate immunity.
| S-EPMC10757368 | biostudies-literature
Project description:Hepatic inflammation is a key pathological feature of Nonalcoholic Steatohepatitis (NASH). Natural Killer T-cells (NKT) and CD8+ T-cells are known to play an important role in obesity related adipose tissue inflammation. We hypothesized that these same inflammatory phenotypes would be present in progressive NASH. We used a previously established high fat high carbohydrate (HFHC) murine obesogenic diet model of progressive NASH to investigate the role of NKT cells and CD8+ T-cells in C57Bl6/J mice. Further, to better understand the impact of these cell populations; CD1d-deficient and CD8+ T-cell depleted mice were subjected to HFHC diet for 16 weeks. C57Bl6/J mice fed HFHC diet had increased body weight, liver triglyceride content, serum alanine aminotransferase (ALT) levels and increased NKT cells and CD8+ T-cells infiltration in the liver. In addition human liver sections from patients with NASH showed increased CD8+ T-cells. In comparison, CD1d-deficient and CD8-T cell depleted mice fed HFHC had lower hepatic triglyceride content, lower ALT levels, as well reduced α-smooth muscle actin (αSMA), collagen type 1 alpha 1 (Col1a1), collagen type 1 alpha 2 (Col1a2) mRNA expression, lower activated resident macrophages and infiltrating macrophages and improved NAFLD activity scores. Further, while CD1d-deficient mice were protected against weight gain on the HFHC diet, CD8 T-cell depleted mice gained weight on the HFHC diet.ConclusionWe found that NASH has an immunological signature that includes hepatic infiltrating NKT and CD8+ T-Cells. Depletion of these cells resulted in reduced NASH progression and thus presents novel therapeutic avenues for the treatment of NASH.
| S-EPMC5687094 | biostudies-literature
Project description:Natural killer cells play a crucial role in the initial defense against bacterial pathogens. The crosstalk between host cells infected with intracellular pathogens and NK cells has been studied intensively, but not much attention has been given to characterize the role of NK cells in the response to extracellular bacterial pathogens such as yersiniae. In this study we used antibody-mediated NK cell depletion to address the importance of this immune cell type in controlling a Y. pseudotuberculosis infection. Analysis of the bacterial counts was used to follow the infection and flow cytometry was performed to characterize the composition and dynamic of immune cells. Depletion of NK cells led to higher bacterial loads within the mesenteric lymph nodes. We further show that in particular CD11b+ CD27+ NK cells which express higher levels of the activation marker CD69 increase within the mesenteric lymph nodes during a Y. pseudotuberculosis infection. Moreover, in response to the activation NK cells secrete higher levels of IFNy, which in turn triggers the production of the proinflammatory cytokine TNFα. These results suggest, that NK cells aid in the clearance of Y. pseudotuberculosis infections mainly by triggering the expression of proinflammatory cytokines manipulating the host immune response.
| S-EPMC4546584 | biostudies-literature
Project description:Human cytomegalovirus (HCMV) causes serious HCMV-related diseases in immunocompromised people. Vaccination is the most effective measure to control infection with the pathogen, yet no vaccine has been licensed till now. We performed a head-to-head comparison of the protective abilities of multiple DNA vaccines in murine model of murine cytomegalovirus (MCMV) infection.Five DNA vaccines were constructed. Four encoding MCMV proteins gp34 (m04), p65 (M84), DNA helicase (M105), and immediate-early 1 protein pp89 (IE-1) , respectively, which were reported to induce CD8+ T cell responses, were compared with the one expressing gB (M55), the neutralizing antibody target antigen, for immune protection in BALB/c mice. Mice were immunized with these DNA vaccines 1 to 4 times via intramuscular injection followed by electroporation, and were subsequently infected with a lethal dose (3?×?LD50) of highly virulent SG-MCMV. Specific antibodies and IFN-? secreting splenocytes were detected by immunoblotting and ELISPOT, respectively. Protective abilities in mice provided by the vaccines were evaluated by residual virus titers in organs, survival rate and weight loss.These DNA vaccines, especially m04, M84 and IE-1, could effectively reduce the virus loads in salivary glands and spleens of mice, but they couldn't completely clear the residual virus. Survival rates of 100% in mice after a lethal dose of MCMV infection could be reached by more than one dose of M84 vaccine or two doses of m04 or IE-1 vaccine. Immunization with M55 or M105 DNA at four doses offered mice only 62.5% survival rate after the lethal challenge.The study demonstrated that DNA vaccines could effectively afford mice protection against infection with a highly virulent MCMV and that the protection offered by induced CD8+ T cell immunity might be superior to that by gB-specific antibodies. These results are valuable references for development and application of HCMV vaccines.
| S-EPMC4073173 | biostudies-literature
Project description:BackgroundToxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite with a broad host range including most warm-blooded animals, including humans. T. gondii surface antigen 1 (SAG1) is a well-characterized T. gondii antigen. T. gondii expresses five nonmitochondrial rhomboid intramembrane proteases, TgROM1-5. TgROM4 is uniformly distributed on the surface of T. gondii and involved in regulating MIC2, MIC3, MIC6, and AMA1 during T. gondii invasion of host cells. Bioinformatics have predicted ROM4 B-cell and T-cell epitopes. Immunization strategy is also a key factor in determining the effectiveness of the immune response and has gained increasing attention in T. gondii vaccine research. In this study, we used a DNA prime-peptide boost vaccination regimen to assess the protective efficacy of various vaccination strategies using TgROM4.MethodsWe identified a polypeptide (YALLGALIPYCVEYWKSIPR) using a bioinformatics approach, and immunized mice using a DNA-prime and polypeptide-boost regimen. BALB/c mice were randomly divided into six groups, including three experimental groups (peptide, pROM4 and pROM4/peptide) and three control groups (PBS, pEGFP-C1 and pSAG1). Mice were then immunized intramuscularly four times. After immunization, IgG and cytokine productions were determined using enzyme-linked immunosorbent assays. The survival time of mice was evaluated after challenge with tachyzoites of T. gondii RH strain. Additionally, the number of cysts in the brain was determined after intragastric challenge with cysts of T. gondii PRU strain.ResultsMice vaccinated with different immunization regimens (peptide, pROM4 and pROM4/peptide) elicited specific humoral and cellular responses, with high levels of IgG, IgG2a, and interferon (IFN)-γ. Moreover, IgG, IgG2a and IFN-γ levels were highest in the pROM4/peptide group. Immunized mice, especially those in the pROM4/peptide group, had prolonged survival times after challenge with tachyzoites and reduced numbers of brain cysts after infection compared with negative controls.ConclusionA DNA prime-peptide boost regimen based on ROM4 elicited the highest level of humoral and cellular immune responses among immunization regimens, and may be a promising approach to increase the efficacy of DNA immunization.
| S-EPMC5225637 | biostudies-literature
Project description:BCG, the only licensed vaccine against tuberculosis (TB), provides geographically variable protection, an effect ascribed to exposure to environmental mycobacteria (EM). Here we show that altering the intestinal microbiota of mice by early-life infection with the commensal bacterium Helicobacter hepaticus (Hh) increases their susceptibility to challenge with Mycobacterium tuberculosis (Mtb). Furthermore Hh-infected mice immunised parenterally with the recombinant subunit vaccine, human adenovirus type 5 expressing the immunodominant antigen 85A of Mtb (Ad85A), display a reduced lung immune response and protection against Mtb challenge is also reduced. Expression of interleukin 10 (IL10) messenger RNA is increased in the colon of Hh infected mice. Treatment of Hh-infected Ad85A-immunised mice with anti-IL10 receptor antibody, following challenge with Mtb, restores the protective effect of the vaccine. These data show for the first time that alteration of the intestinal microbiota by addition of a single commensal organism can profoundly influence protection induced by a TB subunit vaccine via an IL10-dependent mechanism, a result with implications for the deployment of such vaccines in the field.
| S-EPMC4377097 | biostudies-literature
Project description:Human genome-wide association studies found single-nucleotide polymorphisms (SNPs) near LYPLAL1 (Lysophospholipase-like protein 1) that have sex-specific effects on fat distribution and metabolic traits. To determine whether altering LYPLAL1 affects obesity and metabolic disease, we created and characterized a mouse knockout (KO) of Lyplal1. We fed the experimental group of mice a high-fat, high-sucrose (HFHS) diet for 23 weeks, and the controls were fed regular chow diet. Here, we show that CRISPR-Cas9 whole-body Lyplal1 KO mice fed an HFHS diet showed sex-specific differences in weight gain and fat accumulation as compared to chow diet. Female, not male, KO mice weighed less than WT mice, had reduced body fat percentage, had white fat mass, and had adipocyte diameter not accounted for by changes in the metabolic rate. Female, but not male, KO mice had increased serum triglycerides, decreased aspartate, and decreased alanine aminotransferase. Lyplal1 KO mice of both sexes have reduced liver triglycerides and steatosis. These diet-specific effects resemble the effects of SNPs near LYPLAL1 in humans, suggesting that LYPLAL1 has an evolutionary conserved sex-specific effect on adiposity. This murine model can be used to study this novel gene-by-sex-by-diet interaction to elucidate the metabolic effects of LYPLAL1 on human obesity.
| S-EPMC10947332 | biostudies-literature
Project description:BackgroundThe prevalence of non-alcoholic steatohepatitis (NASH) rapidly increases with associated metabolic disorders such as dyslipidemia; therefore, NASH is now considered an independent risk factor of cardiovascular diseases. NASH displays sex-linked epidemiological, phenotypical, and molecular differences; however, little is known about the background of these sex-specific differences on the molecular level.ObjectivesWe aimed to assess sex-specific differences in the expression of inflammatory and fibrotic genes, as well as in cholesterol metabolism, focusing on the expression of Pcsk9 in several tissues in a mouse model of NASH that shows the typical features of the human condition.Methods and resultsWe fed 10-months-old male and female C57Bl/6J mice with a NASH-inducing CDAA or corresponding control diet for 8 weeks. We found that, compared to the control male mice baseline, hepatic Pcsk9 expression as well as serum PCSK9 level was significantly higher in females, and both circulating PCSK9 level and the hepatic Pcsk9 gene were markedly decreased in female mice during NASH development. Histological analysis revealed that male and female mice develop a similar degree of steatosis; however, fibrosis was more pronounced in males upon CDAA diet feeding. Strikingly, female mice have higher hepatic expression of the pro-inflammatory cytokines (Il1b, Ifng), and increased IL-1β cleavage by the NLRP3 inflammasome, and a decrease in Clec4f+ resident Kupffer cell population in comparison to males in the CDAA-fed groups.ConclusionThis is the first demonstration that there are critical sex-specific differences during NASH development in middle-aged mice regarding inflammation, fibrosis, and cholesterol metabolism and that changes in PCSK9 and IL-1β are likely important contributors to sex-specific changes during the transition to NASH.
| S-EPMC7937716 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2024-09-24 | GSE256505 | GEO