scholarly journals High-Fat Diet and Feeding Regime Impairs Number, Phenotype, and Cytotoxicity of Natural Killer Cells in C57BL/6 Mice

2020 ◽  
Vol 7 ◽  
Author(s):  
Julia Spielmann ◽  
Wiebke Naujoks ◽  
Matthias Emde ◽  
Martin Allweyer ◽  
Heike Kielstein ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Real Time ◽  
High Fat Diet ◽  
Nk Cell ◽  
Overweight And Obesity ◽  
High Fat ◽  
Feeding Regime ◽  
Feeding Regimes ◽  
Ad Libitum

Overweight and obesity are major public health challenges worldwide. Obesity is associated with a higher risk for the development of several cancer types, but specific mechanisms underlying the link of obesity and cancer are still unclear. Natural killer (NK) cells are circulating lymphoid cells promoting the elimination of virus-infected and tumor cells. Previous investigations demonstrated conflicting results concerning the influence of obesity on functional NK cell parameters in small animal models. The aim of the present study was to clarify potential obesity-associated alterations of murine NK cells in vivo, implementing different feeding regimes. Therefore, C57BL/6 mice were fed a normal-fat diet (NFD) or high-fat diet (HFD) under restrictive and ad libitum feeding regimes. Results showed diet and feeding-regime dependent differences in body weight, visceral fat mass and plasma cytokine concentrations. Flow cytometry analyses demonstrated significant changes in total cell counts as well as frequencies of immune cell populations in peripheral blood comparing mice fed NFD or HFD in an ad libitum or restrictive manner. Mice fed the HFD showed significantly decreased frequencies of total NK cells and the mature CD11b+CD27+ NK cell subset compared to mice fed the NFD. Feeding HFD resulted in significant changes in the expression of the maturation markers KLRG1 and CD127 in NK cells. Furthermore, real-time PCR analyses of NK-cell related functional parameters in adipose tissue revealed significant diet and feeding-regime dependent differences. Most notable, real-time cytotoxicity assays demonstrated an impaired cytolytic activity of splenic NK cells toward murine colon cancer cells in HFD-fed mice compared to NFD-fed mice. In conclusion, our data demonstrate that feeding a high-fat diet influences the frequency, phenotype and function of NK cells in C57BL/6 mice. Interestingly, restricted feeding of HFD compared to ad libitum feeding resulted in a partial prevention of the obesity-associated alterations on immune cells and especially on NK cells, nicely fitting with the current concept of an advantage for interval fasting for improved health.

scholarly journals The Impact of High-Fat Diet and Restrictive Feeding on Natural Killer Cells in Obese-Resistant BALB/c Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
Julia Spielmann ◽  
Wiebke Naujoks ◽  
Matthias Emde ◽  
Martin Allweyer ◽  
Johannes Fänder ◽  
...  
Keyword(s):  
Nk Cells ◽  
Visceral Fat ◽  
High Fat Diet ◽  
Nk Cell ◽  
Dietary Composition ◽  
High Fat ◽  
Plasma Cytokine ◽  
Increased Risk ◽  
Severe Infections ◽  
Ad Libitum

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.

scholarly journals Aberrant expression of HDL-bound microRNA induced by a high-fat diet in a pig model: implications in the pathogenesis of dyslipidaemia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Guoyuan Sui ◽  
Lianqun Jia ◽  
Nan Song ◽  
Dongyu Min ◽  
Si Chen ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
High Fat Diet ◽  
Enrichment Analysis ◽  
Diet Group ◽  
High Fat ◽  
Positive Regulation ◽  
Aberrant Expression ◽  
Balanced Diet ◽  
Mirna Sequencing

Abstract Background A high-fat diet can affect lipid metabolism and trigger cardiovascular diseases. A growing body of studies has revealed the HDL-bound miRNA profiles in familial hypercholesterolaemia; in sharp contrast, relevant studies on high-fat diet-induced dyslipidaemia are lacking. In the current study, HDL-bound miRNAs altered by a high-fat diet were explored to offer some clues for elucidating their effects on the pathogenesis of dyslipidaemia. Methods Six pigs were randomly divided into two groups of three pigs each, namely, the high-fat diet and the balanced diet groups, which were fed a high-fat diet and balanced diet separately for six months. HDL was separated from plasma, which was followed by dissociation of the miRNA bound to HDL. miRNA sequencing of the isolated miRNA was performed to identify the differential expression profiles between the two groups, which was validated by real-time PCR. TargetScan, miRDB, and miRWalk were used for the prediction of genes targeted by the differential miRNAs. Results Compared with the balanced diet group, the high-fat diet group had significantly higher levels of TG, TC, LDL-C and HDL-C at six months. miRNA sequencing revealed 6 upregulated and 14 downregulated HDL-bound miRNAs in the high-fat diet group compared to the balanced diet group, which was validated by real-time PCR. GO enrichment analysis showed that dysregulated miRNAs in the high-fat diet group were associated with the positive regulation of lipid metabolic processes, positive regulation of lipid biosynthetic processes, and positive regulation of Ras protein signal transduction. Insulin resistance and the Ras signalling pathway were enriched in the KEGG pathway enrichment analysis. Conclusions Twenty HDL-bound miRNAs are significantly dysregulated in high-fat diet-induced dyslipidaemia. This study presents an analysis of a new set of HDL-bound miRNAs that are altered by a high-fat diet and offers some valuable clues for novel mechanistic insights into high-fat diet-induced dyslipidaemia. Further functional verification study using a larger sample size will be required.

scholarly journals Natural Killer Cells Are Present in Rag1−/− Mice and Promote Tissue Damage During the Acute Phase of Ischemic Stroke

2021 ◽  
Author(s):  
Leoni Rolfes ◽  
Tobias Ruck ◽  
Christina David ◽  
Stine Mencl ◽  
Stefanie Bock ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Adoptive Transfer ◽  
Immune Cell ◽  
Nk Cell ◽  
Cell Subset ◽  
Neurological Deficits ◽  
In Vitro Assays ◽  
Experimental Stroke ◽  
Transfer Model

AbstractRag1−/− mice, lacking functional B and T cells, have been extensively used as an adoptive transfer model to evaluate neuroinflammation in stroke research. However, it remains unknown whether natural killer (NK) cell development and functions are altered in Rag1−/− mice as well. This connection has been rarely discussed in previous studies but might have important implications for data interpretation. In contrast, the NOD-Rag1nullIL2rgnull (NRG) mouse model is devoid of NK cells and might therefore eliminate this potential shortcoming. Here, we compare immune-cell frequencies as well as phenotype and effector functions of NK cells in Rag1−/− and wildtype (WT) mice using flow cytometry and functional in vitro assays. Further, we investigate the effect of Rag1−/− NK cells in the transient middle cerebral artery occlusion (tMCAO) model using antibody-mediated depletion of NK cells and adoptive transfer to NRG mice in vivo. NK cells in Rag1−/− were comparable in number and function to those in WT mice. Rag1−/− mice treated with an anti-NK1.1 antibody developed significantly smaller infarctions and improved behavioral scores. Correspondingly, NRG mice supplemented with NK cells were more susceptible to tMCAO, developing infarctions and neurological deficits similar to Rag1−/− controls. Our results indicate that NK cells from Rag1−/− mice are fully functional and should therefore be considered in the interpretation of immune-cell transfer models in experimental stroke. Fortunately, we identified the NRG mice, as a potentially better-suited transfer model to characterize individual cell subset-mediated neuroinflammation in stroke.

scholarly journals The m15 Locus of Murine Cytomegalovirus Modulates Natural Killer Cell Responses to Promote Dissemination to the Salivary Glands and Viral Shedding

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 866
Author(s):  
Baca Chan ◽  
Maja Arapović ◽  
Laura Masters ◽  
Francois Rwandamuiye ◽  
Stipan Jonjić ◽  
...  
Keyword(s):  
Nk Cells ◽  
Salivary Glands ◽  
Natural Killer ◽  
Nk Cell ◽  
Acute Infection ◽  
Killer Cell ◽  
Viral Escape ◽  
Murine Cytomegalovirus ◽  
Viral Shedding ◽  
Cell Responses

As the largest herpesviruses, the 230 kb genomes of cytomegaloviruses (CMVs) have increased our understanding of host immunity and viral escape mechanisms, although many of the annotated genes remain as yet uncharacterised. Here we identify the m15 locus of murine CMV (MCMV) as a viral modulator of natural killer (NK) cell immunity. We show that, rather than discrete transcripts from the m14, m15 and m16 genes as annotated, there are five 3′-coterminal transcripts expressed over this region, all utilising a consensus polyA tail at the end of the m16 gene. Functional inactivation of any one of these genes had no measurable impact on viral replication. However, disruption of all five transcripts led to significantly attenuated dissemination to, and replication in, the salivary glands of multiple strains of mice, but normal growth during acute infection. Disruption of the m15 locus was associated with heightened NK cell responses, including enhanced proliferation and IFNγ production. Depletion of NK cells, but not T cells, rescued salivary gland replication and viral shedding. These data demonstrate the identification of multiple transcripts expressed by a single locus which modulate, perhaps in a concerted fashion, the function of anti-viral NK cells.

scholarly journals Short-course IL-15 given as a continuous infusion led to a massive expansion of effective NK cells: implications for combination therapy with antitumor antibodies

2021 ◽  
Vol 9 (4) ◽  
pp. e002193
Author(s):  
Sigrid P Dubois ◽  
Milos D Miljkovic ◽  
Thomas A Fleisher ◽  
Stefania Pittaluga ◽  
Jennifer Hsu-Albert ◽  
...  
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Intravenous Infusion ◽  
Nk Cell ◽  
Continuous Intravenous Infusion ◽  
Dose Escalation Study ◽  
Link Type ◽  
Best Response ◽  
Antitumor Antibodies ◽  
Interleukin 15

BackgroundFull application of cytokines as oncoimmunotherapeutics requires identification of optimal regimens. Our initial effort with intravenous bolus recombinant human interleukin-15 (rhIL-15) was limited by postinfusional reactions. Subcutaneous injection and continuous intravenous infusion for 10 days (CIV-10) provided rhIL-15 with less toxicity with CIV-10 giving the best increases in CD8+ lymphocytes and natural killer (NK) cells. To ease rhIL-15 administration, we shortened time of infusion. Treatment with rhIL-15 at a dose of 3–5 µg/kg as a 5-day continuous intravenous infusion (CIV-5) had no dose-limiting toxicities while effector cell stimulation was comparable to the CIV-10 regimen.MethodsEleven patients with metastatic cancers were treated with rhIL-15 CIV-5, 3 µg (n=4), 4 µg (n=3), and 5 µg/kg/day (n=4) in a phase I dose-escalation study (April 6, 2012).ResultsImpressive expansions of NK cells were seen at all dose levels (mean 34-fold), including CD56bright NK cells (mean 144-fold for 4 µg/kg), as well as an increase in CD8+ T cells (mean 3.38-fold). At 5 µg/kg/day, there were no dose-limiting toxicities but pulmonary capillary leak and slower patient recovery. This led to our choice of the 4 µg/kg as CIV-5 dose for further testing. Cytolytic capacity of CD56bright and CD56dim NK cells was increased by interleukin-15 assayed by antibody-dependent cellular cytotoxicity (ADCC), natural cytotoxicity and natural killer group 2D-mediated cytotoxicity. The best response was stable disease.ConclusionsIL-15 administered as CIV-5 substantially expanded NK cells with increased cytotoxic functions. Tumor-targeting monoclonal antibodies dependent on ADCC as their mechanism of action including alemtuzumab, obinutuzumab, avelumab, and mogamulizumab could benefit from those NK cell expansions and provide a promising therapeutic strategy.Trial registration numbersNCT01572493, NCT03759184, NCT03905135, NCT04185220 and NCT02689453.

scholarly journals CRISPR-Cas9–Mediated TIM3 Knockout in Human Natural Killer Cells Enhances Growth Inhibitory Effects on Human Glioma Cells

2021 ◽  
Vol 22 (7) ◽  
pp. 3489
Author(s):  
Takayuki Morimoto ◽  
Tsutomu Nakazawa ◽  
Ryosuke Matsuda ◽  
Fumihiko Nishimura ◽  
Mitsutoshi Nakamura ◽  
...  
Keyword(s):  
T Cell ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Protein Complexes ◽  
Lymphocyte Activation ◽  
Exon 2 ◽  
Effector Cells ◽  
Guide Rna ◽  
Human Natural Killer Cells

Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor in adults. Natural Killer (NK) cells are potent cytotoxic effector cells against tumor cells inducing GBM cells; therefore, NK cell based- immunotherapy might be a promising target in GBM. T cell immunoglobulin mucin family member 3 (TIM3), a receptor expressed on NK cells, has been suggested as a marker of dysfunctional NK cells. We established TIM3 knockout in NK cells, using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9). Electroporating of TIM3 exon 2- or exon 5-targeting guide RNA- Cas9 protein complexes (RNPs) inhibited TIM3 expression on NK cells with varying efficacy. T7 endonuclease I mutation detection assays showed that both RNPs disrupted the intended genome sites. The expression of other checkpoint receptors, i.e., programmed cell death 1 (PD1), Lymphocyte-activation gene 3 (LAG3), T cell immunoreceptor with Ig and ITIM domains (TIGIT), and TACTILE (CD96) were unchanged on the TIM3 knockout NK cells. Real time cell growth assays revealed that TIM3 knockout enhanced NK cell–mediated growth inhibition of GBM cells. These results demonstrated that TIM3 knockout enhanced human NK cell mediated cytotoxicity on GBM cells. Future, CRISPR-Cas9 mediated TIM3 knockout in NK cells may prove to be a promising immunotherapeutic alternative in patient with GBM.

scholarly journals α-Pinene Enhances the Anticancer Activity of Natural Killer Cells via ERK/AKT Pathway

2021 ◽  
Vol 22 (2) ◽  
pp. 656
Author(s):  
Hantae Jo ◽  
Byungsun Cha ◽  
Haneul Kim ◽  
Sofia Brito ◽  
Byeong Mun Kwak ◽  
...  
Keyword(s):  
Nk Cells ◽  
Cancer Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Granzyme B ◽  
Akt Pathway ◽  
Cell Cytotoxicity ◽  
Anticancer Effects ◽  
Nk Cell Cytotoxicity

Natural killer (NK) cells are lymphocytes that can directly destroy cancer cells. When NK cells are activated, CD56 and CD107a markers are able to recognize cancer cells and release perforin and granzyme B proteins that induce apoptosis in the targeted cells. In this study, we focused on the role of phytoncides in activating NK cells and promoting anticancer effects. We tested the effects of several phytoncide compounds on NK-92mi cells and demonstrated that α-pinene treatment exhibited higher anticancer effects, as observed by the increased levels of perforin, granzyme B, CD56 and CD107a. Furthermore, α-pinene treatment in NK-92mi cells increased NK cell cytotoxicity in two different cell lines, and immunoblot assays revealed that the ERK/AKT pathway is involved in NK cell cytotoxicity in response to phytoncides. Furthermore, CT-26 colon cancer cells were allografted subcutaneously into BALB/c mice, and α-pinene treatment then inhibited allografted tumor growth. Our findings demonstrate that α-pinene activates NK cells and increases NK cell cytotoxicity, suggesting it is a potential compound for cancer immunotherapy.

Impact of β2 integrin deficiency on mouse natural killer cell development and function

Blood ◽  
2011 ◽  
Vol 117 (10) ◽  
pp. 2874-2882 ◽  
Author(s):  
Karine Crozat ◽  
Céline Eidenschenk ◽  
Baptiste N. Jaeger ◽  
Philippe Krebs ◽  
Sophie Guia ◽  
...  
Keyword(s):  
Cell Surface ◽  
Nk Cells ◽  
Natural Killer ◽  
Nk Cell ◽  
Surface Expression ◽  
Cell Maturation ◽  
Cell Surface Expression ◽  
Mcmv Infection ◽  
Β2 Integrin

Abstract Natural killer (NK) cells are innate immune cells that express members of the leukocyte β2 integrin family in humans and mice. These CD11/CD18 heterodimers play critical roles in leukocyte trafficking, immune synapse formation, and costimulation. The cell-surface expression of one of these integrins, CD11b/CD18, is also recognized as a major marker of mouse NK-cell maturation, but its function on NK cells has been largely ignored. Using N-ethyl-N-nitrosourea (ENU) mutagenesis, we generated a mouse carrying an A → T transverse mutation in the Itgb2 gene, resulting in a mutation that prevented the cell-surface expression of CD18 and its associated CD11a, CD11b, and CD11c proteins. We show that β2 integrin–deficient NK cells have a hyporesponsive phenotype in vitro, and present an alteration of their in vivo developmental program characterized by a selective accumulation of c-kit+ cells. NK-cell missing-self recognition was partially altered in vivo, whereas the early immune response to mouse cytomegalovirus (MCMV) infection occurred normally in CD18-deficient mice. Therefore, β2 integrins are required for optimal NK-cell maturation, but this deficiency is partial and can be bypassed during MCMV infection, highlighting the robustness of antiviral protective responses.

scholarly journals The effect of calorie intake, fasting, and dietary composition on metabolic health and gut microbiota in mice

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ziyi Zhang ◽  
Xiaoyu Chen ◽  
Yuh Jiun Loh ◽  
Xin Yang ◽  
Chenhong Zhang
Keyword(s):  
Gut Microbiota ◽  
High Fat Diet ◽  
Metabolic Health ◽  
Metabolic Phenotype ◽  
Intermittent Fasting ◽  
High Fat ◽  
Eating Pattern ◽  
Positive Effects ◽  
Normal Chow ◽  
Ad Libitum

Abstract Background Calorie restriction (CR) and intermittent fasting (IF) can promote metabolic health through a process that is partially mediated by gut microbiota modulation. To compare the effects of CR and IF with different dietary structures on metabolic health and the gut microbiota, we performed an experiment in which mice were subjected to a CR or IF regimen and an additional IF control (IFCtrl) group whose total energy intake was not different from that of the CR group was included. Each regimen was included for normal chow and high-fat diet. Results We showed that in normal-chow mice, the IFCtrl regimen had similar positive effects on glucose and lipid metabolism as the CR regimen, but the IF regimen showed almost no influence compared to the outcomes observed in the ad libitum group. IF also resulted in improvements, but the effects were less marked than those associate with CR and IFCtrl when the mice were fed a high-fat diet. Moreover, CR created a stable and unique gut microbial community, while the gut microbiota shaped by IF exhibited dynamic changes in fasting-refeeding cycles. At the end of each cycle, the gut microbiota of the IFCtrl mice was similar to that of the CR mice, and the gut microbiota of the IF mice was similar to that of the ad libitum group. When the abundance of Lactobacillus murinus OTU2 was high, the corresponding metabolic phenotype was improved regardless of eating pattern and dietary structure, which might be one of the key bacterial groups in the gut microbiota that is positively correlated with metabolic amelioration. Conclusion There are interactions among the amount of food intake, the diet structure, and the fasting time on metabolic health. The structure and composition of gut microbiota modified by dietary regimens might contribute to the beneficial effects on the host metabolism.

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