NKT Cell Responses to B Cell Lymphoma.

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Li, Junxin; Sun, Wenji; Subrahmanyam, Priyanka B; Page, Carly; Younger, Kenisha M; Tiper, Irina V; Frieman, Matthew; Kimball, Amy S; Webb, Tonya J

2014-06-01

Natural killer T (NKT) cells are a unique subset of CD1d-restricted T lymphocytes that express characteristics of both T cells and natural killer cells. NKT cells mediate tumor immune-surveillance; however, NKT cells are numerically reduced and functionally impaired in lymphoma patients. Many hematologic malignancies express CD1d molecules and co-stimulatory proteins needed to induce anti-tumor immunity by NKT cells, yet most tumors are poorly immunogenic. In this study, we sought to investigate NKT cell responses to B cell lymphoma. In the presence of exogenous antigen, both mouse and human NKT cell lines produce cytokines following stimulation by B cell lymphoma lines. NKT cell populations were examined ex vivo in mouse models of spontaneous B cell lymphoma, and it was found that during early stages, NKT cell responses were enhanced in lymphoma-bearing animals compared to disease-free animals. In contrast, in lymphoma-bearing animals with splenomegaly and lymphadenopathy, NKT cells were functionally impaired. In a mouse model of blastoid variant mantle cell lymphoma, treatment of tumor-bearing mice with a potent NKT cell agonist, α-galactosylceramide (α-GalCer), resulted in a significant decrease in disease pathology. Ex vivo studies demonstrated that NKT cells from α-GalCer treated mice produced IFN-γ following α-GalCer restimulation, unlike NKT cells from vehicle-control treated mice. These data demonstrate an important role for NKT cells in the immune response to an aggressive hematologic malignancy like mantle cell lymphoma.

Differential Role of Cathepsins S and B In Hepatic APC-Mediated NKT Cell Activation and Cytokine Secretion.

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de Mingo Pulido, Álvaro; de Gregorio, Estefanía; Chandra, Shilpi; Colell, Anna; Morales, Albert; Kronenberg, Mitchell; Marí, Montserrat

2018-01-01

Natural killer T (NKT) cells exhibit a specific tissue distribution, displaying the liver the highest NKT/conventional T cell ratio. Upon antigen stimulation, NKT cells secrete Th1 cytokines, including interferon γ (IFNγ), and Th2 cytokines, including IL-4 that recruit and activate other innate immune cells to exacerbate inflammatory responses in the liver. Cysteine cathepsins control hepatic inflammation by regulating κB-dependent gene expression. However, the contribution of cysteine cathepsins other than Cathepsin S to NKT cell activation has remained largely unexplored. Here we report that cysteine cathepsins, cathepsin B (CTSB) and cathepsin S (CTSS), regulate different aspects of NKT cell activation. Inhibition of CTSB or CTSS reduced hepatic NKT cell expansion in a mouse model after LPS challenge. By contrast, only CTSS inhibition reduced IFNγ and IL-4 secretion after in vivo α-GalCer administration. Accordingly, in vitro studies reveal that only CTSS was able to control α-GalCer-dependent loading in antigen-presenting cells (APCs), probably due to altered endolysosomal protein degradation. In summary, our study discloses the participation of cysteine cathepsins, CTSB and CTSS, in the activation of NKT cells in vivo and in vitro .

Differential Role of Cathepsins S and B In Hepatic APC-Mediated NKT Cell Activation and Cytokine Secretion

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Álvaro de Mingo Pulido

2018-02-01

Full Text Available Natural killer T (NKT cells exhibit a specific tissue distribution, displaying the liver the highest NKT/conventional T cell ratio. Upon antigen stimulation, NKT cells secrete Th1 cytokines, including interferon γ (IFNγ, and Th2 cytokines, including IL-4 that recruit and activate other innate immune cells to exacerbate inflammatory responses in the liver. Cysteine cathepsins control hepatic inflammation by regulating κB-dependent gene expression. However, the contribution of cysteine cathepsins other than Cathepsin S to NKT cell activation has remained largely unexplored. Here we report that cysteine cathepsins, cathepsin B (CTSB and cathepsin S (CTSS, regulate different aspects of NKT cell activation. Inhibition of CTSB or CTSS reduced hepatic NKT cell expansion in a mouse model after LPS challenge. By contrast, only CTSS inhibition reduced IFNγ and IL-4 secretion after in vivo α-GalCer administration. Accordingly, in vitro studies reveal that only CTSS was able to control α-GalCer-dependent loading in antigen-presenting cells (APCs, probably due to altered endolysosomal protein degradation. In summary, our study discloses the participation of cysteine cathepsins, CTSB and CTSS, in the activation of NKT cells in vivo and in vitro.

Distribution of intrahepatic T, NK and CD3(+)CD56(+)NKT cells alters after liver transplantation: Shift from innate to adaptive immunity?

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Werner, Jens M; Lang, Corinna; Scherer, Marcus N; Farkas, Stefan A; Geissler, Edward K; Schlitt, Hans J; Hornung, Matthias

2011-07-01

The liver is an immunological organ containing a large number of T, NK and NKT cells, but little is known about intrahepatic immunity after LTx. Here, we investigated whether the distribution of T, NK and CD3(+)CD56(+)NKT cells is altered in transplanted livers under different circumstances. Core biopsies of transplanted livers were stained with antibodies against CD3 and CD56. Several cell populations including T (CD3(+)CD56(-)), NK (CD3(-)CD56(+)) and NKT cells (CD3(+)CD56(+)) were studied by fluorescence microscopy. Cell numbers were analyzed in relation to the time interval after LTx, immunosuppressive therapy and stage of acute graft rejection (measured with the rejection activity index: RAI) compared to tumor free liver tissue from patients after liver resection due to metastatic disease as control. Recruitment of CD3(+)CD56(+)NKT cells revealed a significant decrease during high RAI scores in comparison to low and middle RAI scores (RAI 7-9: 0.03±0.01/HPF vs. RAI 4-6: 0.1±0.005/HPF). CD3(+)CD56(+)NKT cells were also lower during immunosuppressive therapy with tacrolimus (0.03±0.01/HPF) than with cyclosporine (0.1±0.003/HPF), cyclosporine/MMF (0.1±0.003/HPF) or sirolimus (0.1±0.01/HPF) treatment. Intrahepatic T cell numbers increased significantly 50days after LTx compared to control liver tissue (4.5±0.2/HPF vs. 1.9±0.1/HPF). In contrast, NK cells (0.3±0.004/HPF) were significantly fewer in all biopsies after LTx compared to the control (0.7±0.04/HPF). These data indicate significant alterations in the hepatic recruitment of T, NK and CD3(+)CD56(+)NKT cells after LTx. The increase in T cells and the decrease in NK and CD3(+)CD56(+)NKT cells suggest a shift from innate to adaptive hepatic immunity in the liver graft. Copyright © 2011 Elsevier B.V. All rights reserved.

Foxp3 regulates ratio of Treg and NKT cells in a mouse model of asthma.

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Lu, Yanming; Guo, Yinshi; Xu, Linyun; Li, Yaqin; Cao, Lanfang

2015-05-01

Chronic inflammatory disorder of the airways causes asthma. Regulatory T cells (Treg cells) and Natural killer T cells (NKT cells) both play critical roles in the pathogenesis of asthma. Activation of Treg cells requires Foxp3, whereas whether Foxp3 may regulate the ratio of Treg and NKT cells to affect asthma is uncertain. In an ovalbumin (OVA)-induced mouse model of asthma, we either increased Treg cells by lentivirus-mediated forced expression of exogenous Foxp3, or increased NKT cells by stimulation with its activator α-GalCer. We found that the CD4+CD25+ Treg cells increased by forced Foxp3 expression, and decreased by α-GalCer, while the CD3+CD161+ NKT cells decreased by forced Foxp3 expression, and increased by α-GalCer. Moreover, forced Foxp3 expression, but not α-GalCer, significantly alleviated the hallmarks of asthma. Furthermore, forced Foxp3 increased levels of IL_10 and TGFβ1, and α-GalCer increased levels of IL_4 and INFγ in the OVA-treated lung. Taken together, our study suggests that Foxp3 may activate Treg cells and suppress NKT cells in asthma. Treg and NKT cells may antagonize the effects of each other in asthma.

EBV promotes human CD8 NKT cell development.

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Yuling He

2010-05-01

Full Text Available The reports on the origin of human CD8(+ Valpha24(+ T-cell receptor (TCR natural killer T (NKT cells are controversial. The underlying mechanism that controls human CD4 versus CD8 NKT cell development is not well-characterized. In the present study, we have studied total 177 eligible patients and subjects including 128 healthy latent Epstein-Barr-virus(EBV-infected subjects, 17 newly-onset acute infectious mononucleosis patients, 16 newly-diagnosed EBV-associated Hodgkin lymphoma patients, and 16 EBV-negative normal control subjects. We have established human-thymus/liver-SCID chimera, reaggregated thymic organ culture, and fetal thymic organ culture. We here show that the average frequency of total and CD8(+ NKT cells in PBMCs from 128 healthy latent EBV-infected subjects is significantly higher than in 17 acute EBV infectious mononucleosis patients, 16 EBV-associated Hodgkin lymphoma patients, and 16 EBV-negative normal control subjects. However, the frequency of total and CD8(+ NKT cells is remarkably increased in the acute EBV infectious mononucleosis patients at year 1 post-onset. EBV-challenge promotes CD8(+ NKT cell development in the thymus of human-thymus/liver-SCID chimeras. The frequency of total (3% of thymic cells and CD8(+ NKT cells ( approximately 25% of NKT cells is significantly increased in EBV-challenged chimeras, compared to those in the unchallenged chimeras (<0.01% of thymic cells, CD8(+ NKT cells undetectable, respectively. The EBV-induced increase in thymic NKT cells is also reflected in the periphery, where there is an increase in total and CD8(+ NKT cells in liver and peripheral blood in EBV-challenged chimeras. EBV-induced thymic CD8(+ NKT cells display an activated memory phenotype (CD69(+CD45RO(hiCD161(+CD62L(lo. After EBV-challenge, a proportion of NKT precursors diverges from DP thymocytes, develops and differentiates into mature CD8(+ NKT cells in thymus in EBV-challenged human-thymus/liver-SCID chimeras or

NKT cells in leishmaniasis.

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Zamora-Chimal, Jaime; Hernández-Ruiz, Joselín; Becker, Ingeborg

2017-04-01

The role of NKT cells in the resistance or susceptibility towards Leishmania infections remains to be defined, since controversial data persist. The response of these cells seems to depend on many variables such as the infection site, the number of infecting parasites, the virulence of the strain and the Leishmania species. We here revise the activation pathways leading to NKT cell activation. NKT cells can be activated by the direct pathway, in which Leishmania glycolipids are presented by CD1d molecules on antigen presenting cells, such as dendritic cells (DC), leading to the secretion of diverse cytokines by NKT. NKT cells can also be activated by the indirect pathway, in which Leishmania glycolipids, such as LPG, stimulate TLR2 in DC, inducing their IL-12 production, which in turn activates NKT cells. The review further analyzes the role of NKT cells in disease development, both in humans as in mouse models. Finally we propose the activation of NKT cells for controlling Leishmania infections. Copyright © 2016 Elsevier GmbH. All rights reserved.

Zbtb7b (Th-POK) regulates the development of IL-17 producing CD1d-restricted mouse NKT-cells

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Enders, Anselm; Stankovic, Sanda; Teh, Charis; Uldrich, Adam P.; Yabas, Mehmet; Juelich, Torsten; Altin, John A.; Frankenreiter, Sandra; Bergmann, Hannes; Roots, Carla M.; Kyparissoudis, Konstantinos; Goodnow, Chris C.; Godfrey, Dale I.

2012-01-01

CD1d-dependent NKT-cells represent a heterogeneous family of effector T-cells including CD4+CD8− and CD4−CD8− subsets, that respond to glycolipid antigens with rapid and potent cytokine production. NKT-cell development is regulated by a unique combination of factors, however very little is known about factors that control the development of NKT subsets. Here, we analyze a novel mouse strain (helpless) with a mis-sense mutation in the BTB-POZ domain of Zbtb7b and demonstrate that this mutation has dramatic, intrinsic effects on development of NKT-cell subsets. Although NKT-cell numbers are similar in Zbtb7b mutant mice, these cells are hyperproliferative and most lack CD4 and instead express CD8. Moreover, the majority of Zbtb7b mutant NKT-cells in the thymus are RORγt+ and a high frequency produce IL-17 while very few produce IFN-γ or other cytokines, sharply contrasting the profile of normal NKT-cells. Mice heterozygous for the helpless mutation also have reduced numbers of CD4+ NKT-cells and increased production of IL-17 without an increase in CD8+ cells, suggesting that Zbtb7b acts at multiple stages of NKT-cell development. These results reveal Zbtb7b as a critical factor genetically pre-determining the balance of effector subsets within the NKT-cell population. PMID:23105140

ZBTB7B (Th-POK) regulates the development of IL-17-producing CD1d-restricted mouse NKT cells.

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Enders, Anselm; Stankovic, Sanda; Teh, Charis; Uldrich, Adam P; Yabas, Mehmet; Juelich, Torsten; Altin, John A; Frankenreiter, Sandra; Bergmann, Hannes; Roots, Carla M; Kyparissoudis, Konstantinos; Goodnow, Chris C; Godfrey, Dale I

2012-12-01

CD1d-dependent NKT cells represent a heterogeneous family of effector T cells including CD4(+)CD8(-) and CD4(-)CD8(-) subsets that respond to glycolipid Ags with rapid and potent cytokine production. NKT cell development is regulated by a unique combination of factors, however very little is known about factors that control the development of NKT subsets. In this study, we analyze a novel mouse strain (helpless) with a mis-sense mutation in the BTB-POZ domain of ZBTB7B and demonstrate that this mutation has dramatic, intrinsic effects on development of NKT cell subsets. Although NKT cell numbers are similar in Zbtb7b mutant mice, these cells are hyperproliferative and most lack CD4 and instead express CD8. Moreover, the majority of ZBTB7B mutant NKT cells in the thymus are retinoic acid-related orphan receptor γt positive, and a high frequency produce IL-17 while very few produce IFN-γ or other cytokines, sharply contrasting the profile of normal NKT cells. Mice heterozygous for the helpless mutation also have reduced numbers of CD4(+) NKT cells and increased production of IL-17 without an increase in CD8(+) cells, suggesting that ZBTB7B acts at multiple stages of NKT cell development. These results reveal ZBTB7B as a critical factor genetically predetermining the balance of effector subsets within the NKT cell population.

Activated NKT cells facilitated functional switch of myeloid-derived suppressor cells at inflammation sites in fulminant hepatitis mice.

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Wu, Danxiao; Shi, Yu; Wang, Cheng; Chen, Hanwen; Liu, Qiaoyun; Liu, Jianhua; Zhang, Lihuang; Wu, Yihua; Xia, Dajing

2017-02-01

Myeloid-derived suppressor cells (MDSCs) confer immunosuppressive properties, but their roles in fulminant hepatitis have not been well defined. In this study, we systematically examined the distribution of MDSCs in bone marrow (BM), liver and spleen, and their functional and differentiation status in an acute fulminant hepatitis mouse model induced by lipopolysaccharide and D-galactosamine (LPS-GalN). Moreover, the interaction between NKT cells and MDSCs was determined. Our study revealed that BM contained the largest pool of MDSCs during pathogenesis of fulminant hepatitis compared with liver and spleen. MDSCs in liver/spleen expressed higher levels of chemokine receptors such as CCR2, CX3CR1 and CXCR2. At inflamed tissues such as liver or spleen, activated NKT cells induced differentiation of MDSCs through cell-cell interaction, which markedly dampened the immunosuppressive effects and promoted MDSCs to produce pro-inflammatory cytokines and activate inflammatory cells. Our findings thus demonstrated an unexpected pro-inflammatory state for MDSCs, which was mediated by the activated NKT cells that precipitated the differentiation and functional evolution of these MDSCs at sites of inflammation. Copyright © 2016. Published by Elsevier GmbH.

β-Catenin is required for the differentiation of iNKT2 and iNKT17 cells that augment IL-25-dependent lung inflammation

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Berga-Bolaños, Rosa; Sharma, Archna; Steinke, Farrah C.; Pyaram, Kalyani; Kim, Yeung-Hyen; Sultana, Dil A.; Fang, Jessie X.; Chang, Cheong-Hee; Xue, Hai-Hui; Heller, Nicola M.; Sen, Jyoti Misra

2015-01-01

Background Invariant Natural Killer T (iNKT) cells have been implicated in lung inflammation in humans and also shown to be a key cell type in inducing allergic lung inflammation in mouse models. iNKT cells differentiate and acquire functional characteristics during development in the thymus. However, the correlation between development of iNKT cells in the thymus and role in lung inflammation remains unknown. In addition, transcriptional control of differentiation of iNKT cells into iNKT cel...

The interaction between regulatory T cells and NKT cells in the liver: a CD1d bridge links innate and adaptive immunity.

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Hua, Jing; Liang, Shuwen; Ma, Xiong; Webb, Tonya J; Potter, James P; Li, Zhiping

2011-01-01

Regulatory T cells (Tregs) and natural killer T (NKT) cells are two distinct lymphocyte subsets that independently regulate hepatic adaptive and innate immunity, respectively. In the current study, we examine the interaction between Tregs and NKT cells to understand the mechanisms of cross immune regulation by these cells. The frequency and function of Tregs were evaluated in wild type and NKT cell deficient (CD1dko) mice. In vitro lymphocyte proliferation and apoptosis assays were performed with NKT cells co-cultured with Tregs. The ability of Tregs to inhibit NKT cells in vivo was examined by adoptive transfer of Tregs in a model of NKT cell mediated hepatitis. CD1dko mice have a significant reduction in hepatic Tregs. Although, the Tregs from CD1dko mice remain functional and can suppress conventional T cells, their ability to suppress activation induced NKT cell proliferation and to promote NKT cell apoptosis is greatly diminished. These effects are CD1d dependent and require cell to cell contact. Adoptive transfer of Tregs inhibits NKT cell-mediated liver injury. NKT cells promote Tregs, and Tregs inhibit NKT cells in a CD1d dependent manner requiring cell to cell contact. These cross-talk immune regulations provide a linkage between innate and adaptive immunity.

Natural killer T (NKT) cells in autoimmune hepatitis.

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Mattner, Jochen

2013-12-01

Natural killer T (NKT) cells represent an innate-like lymphocyte population endowed with unique antigen recognition and tissue distribution features. Their abundance in the microvascular compartments of the liver allows NKT cells to immediately respond to lipid antigens and soluble factors circulating through the portal vein system by releasing tremendous amounts of different cytokines and chemokines. Subsequently, dependent on the nature of the lipid antigen encountered as well as the accessory signal(s) provided, NKT cells not only contribute to the maintenance of immune tolerance, but also direct adverse immune reactions locally and systemically. Focusing on their potent immunomodulatory features and their interactions with various innate and adaptive immune cells, the role of NKT cells in perpetuating the loss of liver-specific immune tolerance will be discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

NF-κB Protects NKT Cells from Tumor Necrosis Factor Receptor 1-induced Death.

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Kumar, Amrendra; Gordy, Laura E; Bezbradica, Jelena S; Stanic, Aleksandar K; Hill, Timothy M; Boothby, Mark R; Van Kaer, Luc; Joyce, Sebastian

2017-11-15

Semi-invariant natural killer T (NKT) cells are innate-like lymphocytes with immunoregulatory properties. NKT cell survival during development requires signal processing by activated RelA/NF-κB. Nonetheless, the upstream signal(s) integrated by NF-κB in developing NKT cells remains incompletely defined. We show that the introgression of Bcl-x L -coding Bcl2l1 transgene into NF-κB signalling-deficient IκBΔN transgenic mouse rescues NKT cell development and differentiation in this mouse model. We reasoned that NF-κB activation was protecting developing NKT cells from death signals emanating either from high affinity agonist recognition by the T cell receptor (TCR) or from a death receptor, such as tumor necrosis factor receptor 1 (TNFR1) or Fas. Surprisingly, the single and combined deficiency in PKC-θ or CARMA-1-the two signal transducers at the NKT TCR proximal signalling node-only partially recapitulated the NKT cell deficiency observed in IκBΔN tg mouse. Accordingly, introgression of the Bcl2l1 transgene into PKC-θ null mouse failed to rescue NKT cell development. Instead, TNFR1-deficiency, but not the Fas-deficiency, rescued NKT cell development in IκBΔN tg mice. Consistent with this finding, treatment of thymocytes with an antagonist of the inhibitor of κB kinase -which blocks downstream NF-κB activation- sensitized NKT cells to TNF-α-induced cell death in vitro. Hence, we conclude that signal integration by NF-κB protects developing NKT cells from death signals emanating from TNFR1, but not from the NKT TCR or Fas.

A New Mouse Model That Spontaneously Develops Chronic Liver Inflammation and Fibrosis.

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Nina Fransén-Pettersson

Full Text Available Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders.

Type II NKT cells: a distinct CD1d-restricted immune regulatory NKT cell subset.

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Dasgupta, Suryasarathi; Kumar, Vipin

2016-08-01

Type II natural killer T cells (NKT) are a subset of the innate-like CD1d-restricted lymphocytes that are reactive to lipid antigens. Unlike the type I NKT cells, which express a semi-invariant TCR, type II NKT cells express a broader TCR repertoire. Additionally, other features, such as their predominance over type I cells in humans versus mice, the nature of their ligands, CD1d/lipid/TCR binding, and modulation of immune responses, distinguish type II NKT cells from type I NKT cells. Interestingly, it is the self-lipid-reactivity of type II NKT cells that has helped define their physiological role in health and in disease. The discovery of sulfatide as one of the major antigens for CD1d-restricted type II NKT cells in mice has been instrumental in the characterization of these cells, including the TCR repertoire, the crystal structure of the CD1d/lipid/TCR complex, and their function. Subsequently, several other glycolipids and phospholipids from both endogenous and microbial sources have been shown to activate type II NKT cells. The activation of a specific subset of type II NKT cells following administration with sulfatide or lysophosphatidylcholine (LPC) leads to engagement of a dominant immunoregulatory pathway associated with the inactivation of type I NKT cells, conventional dendritic cells, and inhibition of the proinflammatory Th1/Th17 cells. Thus, type II NKT cells have been shown to be immunosuppressive in autoimmune diseases, inflammatory liver diseases, and in cancer. Knowing their relatively higher prevalence in human than type I NKT cells, understanding their biology is imperative for health and disease.

Mouse Hobit is a homolog of the transcriptional repressor Blimp-1 that regulates NKT cell effector differentiation

NARCIS (Netherlands)

van Gisbergen, Klaas P. J. M.; Kragten, Natasja A. M.; Hertoghs, Kirsten M. L.; Wensveen, Felix M.; Jonjic, Stipan; Hamann, Jörg; Nolte, Martijn A.; van Lier, Rene A. W.

2012-01-01

The transcriptional repressor Blimp-1 mediates the terminal differentiation of many cell types, including T cells. Here we identified Hobit (Znf683) as a previously unrecognized homolog of Blimp-1 that was specifically expressed in mouse natural killer T cells (NKT cells). Through studies of

Choline Deficiency Causes Colonic Type II Natural Killer T (NKT) Cell Loss and Alleviates Murine Colitis under Type I NKT Cell Deficiency.

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Sagami, Shintaro; Ueno, Yoshitaka; Tanaka, Shinji; Fujita, Akira; Niitsu, Hiroaki; Hayashi, Ryohei; Hyogo, Hideyuki; Hinoi, Takao; Kitadai, Yasuhiko; Chayama, Kazuaki

2017-01-01

Serum levels of choline and its derivatives are lower in patients with inflammatory bowel disease (IBD) than in healthy individuals. However, the effect of choline deficiency on the severity of colitis has not been investigated. In the present study, we investigated the role of choline deficiency in dextran sulfate sodium (DSS)-induced colitis in mice. Methionine-choline-deficient (MCD) diet lowered the levels of type II natural killer T (NKT) cells in the colonic lamina propria, peritoneal cavity, and mesenteric lymph nodes, and increased the levels of type II NKT cells in the livers of wild-type B6 mice compared with that in mice fed a control (CTR) diet. The gene expression pattern of the chemokine receptor CXCR6, which promotes NKT cell accumulation, varied between colon and liver in a manner dependent on the changes in the type II NKT cell levels. To examine the role of type II NKT cells in colitis under choline-deficient conditions, we assessed the severity of DSS-induced colitis in type I NKT cell-deficient (Jα18-/-) or type I and type II NKT cell-deficient (CD1d-/-) mice fed the MCD or CTR diets. The MCD diet led to amelioration of inflammation, decreases in interferon (IFN)-γ and interleukin (IL)-4 secretion, and a decrease in the number of IFN-γ and IL-4-producing NKT cells in Jα18-/- mice but not in CD1d-/- mice. Finally, adaptive transfer of lymphocytes with type II NKT cells exacerbated DSS-induced colitis in Jα18-/- mice with MCD diet. These results suggest that choline deficiency causes proinflammatory type II NKT cell loss and alleviates DSS-induced colitis. Thus, inflammation in DSS-induced colitis under choline deficiency is caused by type II NKT cell-dependent mechanisms, including decreased type II NKT cell and proinflammatory cytokine levels.

Immunoregulation of NKT Cells in Systemic Lupus Erythematosus.

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Chen, Junwei; Wu, Meng; Wang, Jing; Li, Xiaofeng

2015-01-01

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with different variety of clinical manifestations. Natural killer T (NKT) cells are innate lymphocytes that play a regulatory role during broad range of immune responses. A number of studies demonstrated that the quantity and quality of invariant NKT (iNKT) cells showed marked defects in SLE patients in comparison to healthy controls. This finding suggests that iNKT cells may play a regulatory role in the occurrence and development of this disease. In this review, we mainly summarized the most recent findings about the behavior of NKT cells in SLE patients and mouse models, as well as how NKT cells affect the proportion of T helper cells and the production of autoreactive antibodies in the progress of SLE. This will help people better understand the role of NKT cells in the development of SLE and improve the therapy strategy.

NKT Cell-TCR Expression Activates Conventional T Cells in Vivo, but Is Largely Dispensable for Mature NKT Cell Biology

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Vahl, J. Christoph; Heger, Klaus; Knies, Nathalie; Hein, Marco Y.; Boon, Louis; Yagita, Hideo; Polic, Bojan; Schmidt-Supprian, Marc

2013-01-01

Natural killer T (NKT) cell development depends on recognition of self-glycolipids via their semi-invariant Vα14i-TCR. However, to what extent TCR-mediated signals determine identity and function of mature NKT cells remains incompletely understood. To address this issue, we developed a mouse strain allowing conditional Vα14i-TCR expression from within the endogenous Tcrα locus. We demonstrate that naïve T cells are activated upon replacement of their endogenous TCR repertoire with Vα14i-restricted TCRs, but they do not differentiate into NKT cells. On the other hand, induced TCR ablation on mature NKT cells did not affect their lineage identity, homeostasis, or innate rapid cytokine secretion abilities. We therefore propose that peripheral NKT cells become unresponsive to and thus are independent of their autoreactive TCR. PMID:23853545

NKT cell-TCR expression activates conventional T cells in vivo, but is largely dispensable for mature NKT cell biology.

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J Christoph Vahl

Full Text Available Natural killer T (NKT cell development depends on recognition of self-glycolipids via their semi-invariant Vα14i-TCR. However, to what extent TCR-mediated signals determine identity and function of mature NKT cells remains incompletely understood. To address this issue, we developed a mouse strain allowing conditional Vα14i-TCR expression from within the endogenous Tcrα locus. We demonstrate that naïve T cells are activated upon replacement of their endogenous TCR repertoire with Vα14i-restricted TCRs, but they do not differentiate into NKT cells. On the other hand, induced TCR ablation on mature NKT cells did not affect their lineage identity, homeostasis, or innate rapid cytokine secretion abilities. We therefore propose that peripheral NKT cells become unresponsive to and thus are independent of their autoreactive TCR.

[Regulatory role of NKT cells in the prevention of type 1 diabetes].

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Ghazarian, Liana; Simoni, Yannick; Pingris, Karine; Beaudoin, Lucie; Lehuen, Agnès

2013-01-01

Type 1 diabetes is an autoimmune disease resulting from the destruction of pancreatic β cells by the immune system. NKT cells are innate-like T cells that can exert potent immuno-regulatory functions. The regulatory role of NKT cells was initially proposed after the observed decreased frequency of this subset in mouse models of type 1 diabetes, as well as in patients developing various autoimmune pathologies. Increasing NKT cell frequency and function prevent the development of type 1 diabetes in mouse models. Several mechanisms including IL-4 and IL-10 production by NKT cells and the accumulation of tolerogenic dendritic cells are critical for the dampening of pathogenic anti-islet T cell responses by NKT cells. Importantly, these cells can at the same time prevent diabetes and promote efficient immune responses against infectious agents. These results strengthen the potential role of NKT cells as a key target for the development of therapeutic strategies against type 1 diabetes. © 2013 médecine/sciences – Inserm.

Invariant NKT cells are required for airway inflammation induced by environmental antigens

OpenAIRE

Wingender, Gerhard; Rogers, Paul; Batzer, Glenda; Lee, Myung Steve; Bai, Dong; Pei, Bo; Khurana, Archana; Kronenberg, Mitchell; Horner, Anthony A.

2011-01-01

Invariant NKT cells (iNKT cells) are a unique subset of T lymphocytes that rapidly carry out effector functions. In this study, we report that a majority of sterile house dust extracts (HDEs) tested contained antigens capable of activating mouse and human iNKT cells. HDEs had adjuvant-like properties in an ovalbumin (OVA)-induced asthma model, which were dependent on V?14i NKT cells, as vaccinated animals deficient for iNKT cells displayed significantly attenuated immune responses and airway ...

RASAL3, a novel hematopoietic RasGAP protein, regulates the number and functions of NKT cells.

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Saito, Suguru; Kawamura, Toshihiko; Higuchi, Masaya; Kobayashi, Takahiro; Yoshita-Takahashi, Manami; Yamazaki, Maya; Abe, Manabu; Sakimura, Kenji; Kanda, Yasuhiro; Kawamura, Hiroki; Jiang, Shuying; Naito, Makoto; Yoshizaki, Takumi; Takahashi, Masahiko; Fujii, Masahiro

2015-05-01

Ras GTPase-activating proteins negatively regulate the Ras/Erk signaling pathway, thereby playing crucial roles in the proliferation, function, and development of various types of cells. In this study, we identified a novel Ras GTPase-activating proteins protein, RASAL3, which is predominantly expressed in cells of hematopoietic lineages, including NKT, B, and T cells. We established systemic RASAL3-deficient mice, and the mice exhibited a severe decrease in NKT cells in the liver at 8 weeks of age. The treatment of RASAL3-deficient mice with α-GalCer, a specific agonist for NKT cells, induced liver damage, but the level was less severe than that in RASAL3-competent mice, and the attenuated liver damage was accompanied by a reduced production of interleukin-4 and interferon-γ from NKT cells. RASAL3-deficient NKT cells treated with α-GalCer in vitro presented augmented Erk phosphorylation, suggesting that there is dysregulated Ras signaling in the NKT cells of RASAL3-deficient mice. Taken together, these results suggest that RASAL3 plays an important role in the expansion and functions of NKT cells in the liver by negatively regulating Ras/Erk signaling, and might be a therapeutic target for NKT-associated diseases. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regulation of NKT Cell Localization in Homeostasis and Infection

Science.gov (United States)

Slauenwhite, Drew; Johnston, Brent

2015-01-01

Natural killer T (NKT) cells are a specialized subset of T lymphocytes that regulate immune responses in the context of autoimmunity, cancer, and microbial infection. Lipid antigens derived from bacteria, parasites, and fungi can be presented by CD1d molecules and recognized by the canonical T cell receptors on NKT cells. Alternatively, NKT cells can be activated through recognition of self-lipids and/or pro-inflammatory cytokines generated during infection. Unlike conventional T cells, only a small subset of NKT cells traffic through the lymph nodes under homeostatic conditions, with the largest NKT cell populations localizing to the liver, lungs, spleen, and bone marrow. This is thought to be mediated by differences in chemokine receptor expression profiles. However, the impact of infection on the tissue localization and function of NKT remains largely unstudied. This review focuses on the mechanisms mediating the establishment of peripheral NKT cell populations during homeostasis and how tissue localization of NKT cells is affected during infection. PMID:26074921

Regulation of NKT Cell Localization in Homeostasis and Infection.

Science.gov (United States)

Slauenwhite, Drew; Johnston, Brent

2015-01-01

Natural killer T (NKT) cells are a specialized subset of T lymphocytes that regulate immune responses in the context of autoimmunity, cancer, and microbial infection. Lipid antigens derived from bacteria, parasites, and fungi can be presented by CD1d molecules and recognized by the canonical T cell receptors on NKT cells. Alternatively, NKT cells can be activated through recognition of self-lipids and/or pro-inflammatory cytokines generated during infection. Unlike conventional T cells, only a small subset of NKT cells traffic through the lymph nodes under homeostatic conditions, with the largest NKT cell populations localizing to the liver, lungs, spleen, and bone marrow. This is thought to be mediated by differences in chemokine receptor expression profiles. However, the impact of infection on the tissue localization and function of NKT remains largely unstudied. This review focuses on the mechanisms mediating the establishment of peripheral NKT cell populations during homeostasis and how tissue localization of NKT cells is affected during infection.

Inhibitory function of NKT cells during early induction phase of nickel allergy.

Science.gov (United States)

Okuno, Hironori; Satoh, Masashi; Takeuchi, Emiko; Eshima, Koji; Terashima, Masazumi; Komotori, Jun; Habu, Sonoko; Tamauchi, Hidekazu; Iwabuchi, Kazuya

2016-07-01

Until now, metal allergies have been regarded as a Th1-type immune response.　However, because the contribution of a Th2-type immune response has been suggested by clinical findings, we previously examined the Th2-type immune response during the development of metal allergies using a GATA-3 transgenic (GATA-3 Tg) mouse model. As a result, a Th2-type immunization reaction was suggested to be involved in the early phase of metal allergies. Recently, the involvement of NKT cells in metal allergies has been suggested. We examined this possibility using the activation of NKT cells and an NKT cell-deficient mouse model to determine the contribution of NKT cells to nickel allergy in the present study. In NKT cell-deficient mice, ear swelling was remarkably increased, compared with that in control mice. Also, in mice that had been treated with α-galactosylceramide (α-GalCer) to activate NKT cells, the ear swelling response was remarkably inhibited, compared with that in untreated mice. These facts show that NKT cells are involved in the inhibition of nickel allergy-induced ear swelling responses. Copyright © 2016 Elsevier GmbH. All rights reserved.

CD205-TLR9-IL-12 axis contributes to CpG-induced oversensitive liver injury in HBsAg transgenic mice by promoting the interaction of NKT cells with Kupffer cells.

Science.gov (United States)

Hou, Xin; Hao, Xiaolei; Zheng, Meijuan; Xu, Congfei; Wang, Jun; Zhou, Rongbin; Tian, Zhigang

2017-08-01

Gut-derived bacterial products contribute to liver inflammation and injury during chronic hepatitis B virus infection; however, the underlying mechanisms remain obscure. In this study, hepatitis B surface antigen transgenic (HBs-Tg) mice and their wild-type (WT) control C57BL/6 mice were injected with CpG-oligodeoxynucleotides (ODNs) to mimic the translocation of gut microbial products into the systemic circulation. We found that, compared with the WT mice, the HBs-Tg mice were oversensitive to CpG-ODN-induced liver injury, which was dependent on natural killer T (NKT) cells. CpG-ODN injection enhanced the expression of Fas ligand (FasL) on NKT cells. In addition, hepatocytes from the HBs-Tg mice expressed higher levels of Fas than did those from the WT mice, which was further augmented by CpG-ODN. Interaction of Fas and FasL was involved in the cytotoxicity of NKT cells against hepatocytes in the HBs-Tg mice. Moreover, Kupffer cells in the HBs-Tg mice expressed higher levels of CD205 and produced greater amounts of interleukin (IL)-12 than did those in the WT mice. Finally, the depletion of Kupffer cells, neutralization of IL-12 or specific silencing of CD205 on Kupffer cells significantly inhibited CpG-ODN-induced liver injury and NKT activation in the HBs-Tg mice. Our data suggest that CD205-expressing Kupffer cells respond to CpG-ODNs and subsequently release IL-12 to promote NKT cell activation. Activated NKT cells induce liver damage through the Fas signaling pathway in HBs-Tg mice.

Endogenous collagen peptide activation of CD1d-restricted NKT cells ameliorates tissue-specific inflammation in mice

DEFF Research Database (Denmark)

Liu, Yawei; Teige, Anna; Mondoc, Emma

2011-01-01

NKT cells in the mouse recognize antigen in the context of the MHC class I-like molecule CD1d and play an important role in peripheral tolerance and protection against autoimmune and other diseases. NKT cells are usually activated by CD1d-presented lipid antigens. However, peptide recognition...... in the context of CD1 has also been documented, although no self-peptide ligands have been reported to date. Here, we have identified an endogenous peptide that is presented by CD1d to activate mouse NKT cells. This peptide, the immunodominant epitope from mouse collagen type II (mCII707-721), was not associated...... with either MHC class I or II. Activation of CD1d-restricted mCII707-721-specific NKT cells was induced via TCR signaling and classical costimulation. In addition, mCII707-721-specific NKT cells induced T cell death through Fas/FasL, in an IL-17A-independent fashion. Moreover, mCII707-721-specific NKT cells...

Invariant NKT cells: regulation and function during viral infection.

Directory of Open Access Journals (Sweden)

Jennifer A Juno

Full Text Available Natural killer T cells (NKT cells represent a subset of T lymphocytes that express natural killer (NK cell surface markers. A subset of NKT cells, termed invariant NKT cells (iNKT, express a highly restricted T cell receptor (TCR and respond to CD1d-restricted lipid ligands. iNKT cells are now appreciated to play an important role in linking innate and adaptive immune responses and have been implicated in infectious disease, allergy, asthma, autoimmunity, and tumor surveillance. Advances in iNKT identification and purification have allowed for the detailed study of iNKT activity in both humans and mice during a variety of chronic and acute infections. Comparison of iNKT function between non-pathogenic simian immunodeficiency virus (SIV infection models and chronic HIV-infected patients implies a role for iNKT activity in controlling immune activation. In vitro studies of influenza infection have revealed novel effector functions of iNKT cells including IL-22 production and modulation of myeloid-derived suppressor cells, but ex vivo characterization of human iNKT cells during influenza infection are lacking. Similarly, as recent evidence suggests iNKT involvement in dengue virus pathogenesis, iNKT cells may modulate responses to a number of emerging pathogens. This Review will summarize current knowledge of iNKT involvement in responses to viral infections in both human and mouse models and will identify critical gaps in knowledge and opportunities for future study. We will also highlight recent efforts to harness iNKT ligands as vaccine adjuvants capable of improving vaccination-induced cellular immune responses.

Pathogen-expanded CD11b+ invariant NKT cells feedback inhibit T cell proliferation via membrane-bound TGF-β1.

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Han, Yanmei; Jiang, Zhengping; Chen, Zhubo; Gu, Yan; Liu, Yanfang; Zhang, Xiang; Cao, Xuetao

2015-04-01

Natural killer T cells (NKT cells) are effector cells, but also regulator of immune response, which either promote or suppress immune response through production of different cytokines. However, the subsets of NKT cells with definite phenotype and regulatory function need to be further identified. Furthermore, the mechanisms for NKT cells to regulate immune response remain to be fully elucidated. Here we identified CD11b(+) invariant NKT (CD11b(+) iNKT) cells as a new subset of regulatory NKT cells in mouse models with infection. αGalCer:CD1d complex(+)TCRβ(+)NK1.1(+) NKT cells could be categorized to CD11b(+) and CD11b(-) subsets. NKT cells are enriched in liver. During Listeria monocytogenes infection, hepatic CD11b(+) iNKT cells were significantly induced and expanded, with peak expansion on day 8. CD11b(+) iNKT cells were also expanded significantly in spleen and mesenteric lymph nodes. As compared to CD11b(-) iNKT cells, CD11b(+) iNKT cells expressed higher levels of CD27, FasL, B7H1, CD69, and particularly higher level of membrane-bound TGF-β1 (mTGF-β1), but produced less IFN-γ, IL-4, IL-10 and TGF-β1. Hepatic CD11b(+) iNKT cells suppressed antigen-nonspecific and OVA-specific CD4 and CD8 T cell proliferation through mTGF-β1 both in vitro and in vivo, meanwhile, they did not interfere with activation of CD4 T cells and cytotoxicity of the activated CD8 T cells. Thus, we have identified a new subset of pathogen-expanded CD11b(+) invariant NKT cells which can feedback inhibit T cell response through cell-to-cell contact via cell surface (membrane-bound) TGF-β1, especially at the late stage of immune response against infection. CD11b(+) regulatory iNKT cells may contribute to protect host from pathological injure by preventing immune overactivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adipose tissue invariant NKT cells protect against diet-induced obesity and metabolic disorder through regulatory cytokine production.

LENUS (Irish Health Repository)

Lynch, Lydia

2012-09-21

Invariant natural killer T (iNKT) cells are evolutionarily conserved innate T cells that influence inflammatory responses. We have shown that iNKT cells, previously thought to be rare in humans, were highly enriched in human and murine adipose tissue, and that as adipose tissue expanded in obesity, iNKT cells were depleted, correlating with proinflammatory macrophage infiltration. iNKT cell numbers were restored in mice and humans after weight loss. Mice lacking iNKT cells had enhanced weight gain, larger adipocytes, fatty livers, and insulin resistance on a high-fat diet. Adoptive transfer of iNKT cells into obese mice or in vivo activation of iNKT cells via their lipid ligand, alpha-galactocylceramide, decreased body fat, triglyceride levels, leptin, and fatty liver and improved insulin sensitivity through anti-inflammatory cytokine production by adipose-derived iNKT cells. This finding highlights the potential of iNKT cell-targeted therapies, previously proven to be safe in humans, in the management of obesity and its consequences.

Extracellular adenosine controls NKT-cell-dependent hepatitis induction.

Science.gov (United States)

Subramanian, Meenakshi; Kini, Radhika; Madasu, Manasa; Ohta, Akiko; Nowak, Michael; Exley, Mark; Sitkovsky, Michail; Ohta, Akio

2014-04-01

Extracellular adenosine regulates inflammatory responses via the A2A adenosine receptor (A2AR). A2AR deficiency results in much exaggerated acute hepatitis, indicating nonredundancy of adenosine-A2AR pathway in inhibiting immune activation. To identify a critical target of immunoregulatory effect of extracellular adenosine, we focused on NKT cells, which play an indispensable role in hepatitis. An A2AR agonist abolished NKT-cell-dependent induction of acute hepatitis by concanavalin A (Con A) or α-galactosylceramide in mice, corresponding to downregulation of activation markers and cytokines in NKT cells and of NK-cell co-activation. These results show that A2AR signaling can downregulate NKT-cell activation and suppress NKT-cell-triggered inflammatory responses. Next, we hypothesized that NKT cells might be under physiological control of the adenosine-A2AR pathway. Indeed, both Con A and α-galactosylceramide induced more severe hepatitis in A2AR-deficient mice than in WT controls. Transfer of A2AR-deficient NKT cells into A2AR-expressing recipients resulted in exaggeration of Con A-induced liver damage, suggesting that NKT-cell activation is controlled by endogenous adenosine via A2AR, and this physiological regulatory mechanism of NKT cells is critical in the control of tissue-damaging inflammation. The current study suggests the possibility to manipulate NKT-cell activity in inflammatory disorders through intervention to the adenosine-A2AR pathway. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Histone demethylases UTX and JMJD3 are required for NKT cell development in mice.

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Northrup, Daniel; Yagi, Ryoji; Cui, Kairong; Proctor, William R; Wang, Chaochen; Placek, Katarzyna; Pohl, Lance R; Wang, Rongfu; Ge, Kai; Zhu, Jinfang; Zhao, Keji

2017-01-01

Natural killer (NK)T cells and conventional T cells share phenotypic characteristic however they differ in transcription factor requirements and functional properties. The role of histone modifying enzymes in conventional T cell development has been extensively studied, little is known about the function of enzymes regulating histone methylation in NKT cells. We show that conditional deletion of histone demethylases UTX and JMJD3 by CD4-Cre leads to near complete loss of liver NKT cells, while conventional T cells are less affected. Loss of NKT cells is cell intrinsic and not due to an insufficient selection environment. The absence of NKT cells in UTX/JMJD3-deficient mice protects mice from concanavalin A-induced liver injury, a model of NKT-mediated hepatitis. GO-analysis of RNA-seq data indicates that cell cycle genes are downregulated in UTX/JMJD3-deleted NKT progenitors, and suggest that failed expansion may account for some of the cellular deficiency. The phenotype appears to be demethylase-dependent, because UTY, a homolog of UTX that lacks catalytic function, is not sufficient to restore their development and removal of H3K27me3 by deletion of EZH2 partially rescues the defect. NKT cell development and gene expression is sensitive to proper regulation of H3K27 methylation. The H3K27me3 demethylase enzymes, in particular UTX, promote NKT cell development, and are required for effective NKT function.

Endogenous collagen peptide activation of CD1d-restricted NKT cells ameliorates tissue-specific inflammation in mice.

Science.gov (United States)

Liu, Yawei; Teige, Anna; Mondoc, Emma; Ibrahim, Saleh; Holmdahl, Rikard; Issazadeh-Navikas, Shohreh

2011-01-01

NKT cells in the mouse recognize antigen in the context of the MHC class I-like molecule CD1d and play an important role in peripheral tolerance and protection against autoimmune and other diseases. NKT cells are usually activated by CD1d-presented lipid antigens. However, peptide recognition in the context of CD1 has also been documented, although no self-peptide ligands have been reported to date. Here, we have identified an endogenous peptide that is presented by CD1d to activate mouse NKT cells. This peptide, the immunodominant epitope from mouse collagen type II (mCII707-721), was not associated with either MHC class I or II. Activation of CD1d-restricted mCII707-721-specific NKT cells was induced via TCR signaling and classical costimulation. In addition, mCII707-721-specific NKT cells induced T cell death through Fas/FasL, in an IL-17A-independent fashion. Moreover, mCII707-721-specific NKT cells suppressed a range of in vivo inflammatory conditions, including delayed-type hypersensitivity, antigen-induced airway inflammation, collagen-induced arthritis, and EAE, which were all ameliorated by mCII707-721 vaccination. The findings presented here offer new insight into the intrinsic roles of NKT cells in health and disease. Given the results, endogenous collagen peptide activators of NKT cells may offer promise as novel therapeutics in tissue-specific autoimmune and inflammatory diseases.

Critical role for CD1d-restricted invariant NKT cells in stimulating intrahepatic CD8 T-cell responses to liver antigen

NARCIS (Netherlands)

Sprengers, Dave; Sillé, Fenna C. M.; Derkow, Katja; Besra, Gurdyal S.; Janssen, Harry L. A.; Schott, Eckart; Boes, Marianne

2008-01-01

V alpha14 invariant natural killer T cells (iNKT) are localized in peripheral tissues such as the liver rather than lymphoid tissues. Therefore, their role in modulating the stimulation of conventional, major histocompatibility complex (MHC)-restricted T-cell responses has remained ambiguous. We

Invariant NKT cells are required for airway inflammation induced by environmental antigens.

Science.gov (United States)

Wingender, Gerhard; Rogers, Paul; Batzer, Glenda; Lee, Myung Steve; Bai, Dong; Pei, Bo; Khurana, Archana; Kronenberg, Mitchell; Horner, Anthony A

2011-06-06

Invariant NKT cells (iNKT cells) are a unique subset of T lymphocytes that rapidly carry out effector functions. In this study, we report that a majority of sterile house dust extracts (HDEs) tested contained antigens capable of activating mouse and human iNKT cells. HDEs had adjuvant-like properties in an ovalbumin (OVA)-induced asthma model, which were dependent on Vα14i NKT cells, as vaccinated animals deficient for iNKT cells displayed significantly attenuated immune responses and airway inflammation. Furthermore, the administration of HDEs together with OVA mutually augmented the synthesis of cytokines by Vα14i NKT cells and by conventional CD4(+) T cells in the lung, demonstrating a profound immune response synergy for both Th2 cytokines and IL-17A. These data demonstrate that iNKT cell antigens are far more widely dispersed in the environment than previously anticipated. Furthermore, as the antigenic activity in different houses varied greatly, they further suggest that iNKT cell responses to ambient antigens, particular to certain environments, might promote sensitization to conventional respiratory allergens.

The Tec kinase ITK regulates thymic expansion, emigration, and maturation of γδ NKT cells.

Science.gov (United States)

Yin, Catherine C; Cho, Ok Hyun; Sylvia, Katelyn E; Narayan, Kavitha; Prince, Amanda L; Evans, John W; Kang, Joonsoo; Berg, Leslie J

2013-03-15

The Tec family tyrosine kinase, Itk, regulates signaling downstream of the TCR. The absence of Itk in CD4(+) T cells results in impaired Th2 responses along with defects in maturation, cytokine production, and survival of iNKT cells. Paradoxically, Itk(-/-) mice have spontaneously elevated serum IgE levels, resulting from an expansion of the Vγ1.1(+)Vδ6.3(+) subset of γδ T cells, known as γδ NKT cells. Comparisons between γδ NKT cells and αβ iNKT cells showed convergence in the pattern of cell surface marker expression, cytokine profiles, and gene expression, suggesting that these two subsets of NKT cells undergo similar differentiation programs. Hepatic γδ NKT cells have an invariant TCR and are derived predominantly from fetal progenitors that expand in the thymus during the first weeks of life. The adult thymus contains these invariant γδ NKT cells plus a heterogeneous population of Vγ1.1(+)Vδ6.3(+) T cells with diverse CDR3 sequences. This latter population, normally excluded from the liver, escapes the thymus and homes to the liver when Itk is absent. In addition, Itk(-/-) γδ NKT cells persistently express high levels of Zbtb16 (PLZF) and Il4, genes that are normally downregulated in the most mature subsets of NKT cells. These data indicate that Itk signaling is required to prevent the expansion of γδ NKT cells in the adult thymus, to block their emigration, and to promote terminal NKT cell maturation.

NKp46 identifies an NKT cell subset susceptible to leukemic transformation in mouse and human

Science.gov (United States)

Yu, Jianhua; Mitsui, Takeki; Wei, Min; Mao, Hsiaoyin; Butchar, Jonathan P.; Shah, Mithun Vinod; Zhang, Jianying; Mishra, Anjali; Alvarez-Breckenridge, Christopher; Liu, Xingluo; Liu, Shujun; Yokohama, Akihiko; Trotta, Rossana; Marcucci, Guido; Benson, Don M.; Loughran, Thomas P.; Tridandapani, Susheela; Caligiuri, Michael A.

2011-01-01

IL-15 may have a role in the development of T cell large granular lymphocyte (T-LGL) or NKT leukemias. However, the mechanisms of action and the identity of the cell subset that undergoes leukemic transformation remain elusive. Here we show that in both mice and humans, NKp46 expression marks a minute population of WT NKT cells with higher activity and potency to become leukemic. Virtually 100% of T-LGL leukemias in IL-15 transgenic mice expressed NKp46, as did a majority of human T-LGL leukemias. The minute NKp46+ NKT population, but not the NKp46– NKT population, was selectively expanded by overexpression of endogenous IL-15. Importantly, IL-15 transgenic NKp46– NKT cells did not become NKp46+ in vivo, suggesting that NKp46+ T-LGL leukemia cells were the malignant counterpart of the minute WT NKp46+ NKT population. Mechanistically, NKp46+ NKT cells possessed higher responsiveness to IL-15 in vitro and in vivo compared with that of their NKp46– NKT counterparts. Furthermore, interruption of IL-15 signaling using a neutralizing antibody could prevent LGL leukemia in IL-15 transgenic mice. Collectively, our data demonstrate that NKp46 identifies a functionally distinct NKT subset in mice and humans that appears to be directly susceptible to leukemic transformation when IL-15 is overexpressed. Thus, IL-15 signaling and NKp46 may be useful targets in the treatment of patients with T-LGL or NKT leukemia. PMID:21364281

Recognition of lysophosphatidylcholine by type II NKT cells and protection from an inflammatory liver disease.

Science.gov (United States)

Maricic, Igor; Girardi, Enrico; Zajonc, Dirk M; Kumar, Vipin

2014-11-01

Lipids presented by the MHC class I-like molecule, CD1d, are recognized by NK T (NKT) cells, which can be broadly categorized into two subsets. The well-characterized type I NKT cells express a semi-invariant TCR and can recognize both α- and β-linked glycolipids, whereas type II NKT cells are less well studied, express a relatively diverse TCR repertoire, and recognize β-linked lipids. Recent structural studies have shown a distinct mode of recognition of a self-glycolipid sulfatide bound to CD1d by a type II NKT TCR. To further characterize Ag recognition by these cells, we have used the structural data and screened other small molecules able to bind to CD1d and activate type II NKT cells. Using plate-bound CD1d and APC-based Ag presentation assay, we found that phospholipids such as lysophosphatidylcholine (LPC) can stimulate the sulfatide-reactive type II NKT hybridoma Hy19.3 in a CD1d-dependent manner. Using plasmon resonance studies, we found that this type II NKT TCR binds with CD1d-bound LPC with micromolar affinities similar to that for sulfatide. Furthermore, LPC-mediated activation of type II NKT cells leads to anergy induction in type I NKT cells and affords protection from Con A-induced hepatitis. These data indicate that, in addition to self-glycolipids, self-lysophospholipids are also recognized by type II NKT cells. Because lysophospholipids are involved during inflammation, our findings have implications for not only understanding activation of type II NKT cells in physiological settings, but also for the development of immune intervention in inflammatory diseases. Copyright © 2014 by The American Association of Immunologists, Inc.

TNF-α production in NKT cell hybridoma is regulated by sphingosine-1-phosphate: implications for inflammation in atherosclerosis.

Science.gov (United States)

Ito, Shiori; Iwaki, Soichiro; Kondo, Rie; Satoh, Masashi; Iwabuchi, Kazuya; Ohkawa, Ryunosuke; Mishima, Yuko; Yatomi, Yutaka; Furumoto, Tomoo; Tsutsui, Hiroyuki; Fujii, Satoshi

2014-06-01

Natural killer T (NKT) cells are unique T lymphocytes that recognize glycolipid antigen and produce various cytokines. NKT cells accelerate atherosclerosis in mice. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid and regulates T-lymphocyte trafficking. We aimed to determine the effects of S1P on the production of proinflammatory cytokine, tumor necrosis factor (TNF)-α, in NKT cell hybridomas and mouse NKT cells. NKT cell hybridomas and sorted mouse NKT cells were stimulated with S1P and α-galactosylceramide (α-GalCer), the major ligand to produce cytokines in NKT cells. TNF-α mRNA expression and protein production were determined by real-time PCR and ELISA, respectively. Cell migration was assayed using chemotaxicell. Plasma S1P was measured using HPLC. Hybridomas expressed S1P receptors, S1P1, S1P2, and S1P4. S1P and α-GalCer increased TNF-α mRNA expression and protein production. S1P enhanced TNF-α induction by α-GalCer. S1P receptor antagonists decreased the TNF-α mRNA expression induced by S1P. FTY720, an immunosuppressive S1P receptor modulator, also decreased the TNF-α mRNA expression. The migration of NKT cell hybridomas was increased by S1P. FTY720 reduced the migration induced by S1P. S1P also increased the TNF-α mRNA expression in mouse NKT cells. Plasma TNF-α levels in patients with high plasma S1P (≥500 nmol/l) were higher than those in patients with low S1P (NKT cells and enhances TNF-α production. TNF-α overproduction may induce atherogenic inflammatory responses. S1P may serve as a novel therapeutic target for amelioration of vascular inflammatory diseases.

The split personality of NKT cells in malignancy, autoimmune and allergic disorders

Science.gov (United States)

Subleski, Jeff J; Jiang, Qun; Weiss, Jonathan M; Wiltrout, Robert H

2011-01-01

NKT cells are a heterogeneous subset of specialized, self-reactive T cells, with innate and adaptive immune properties, which allow them to bridge innate and adaptive immunity and profoundly influence autoimmune and malignant disease outcomes. NKT cells mediate these activities through their ability to rapidly express pro- and anti-inflammatory cytokines that influence the type and magnitude of the immune response. Not only do NKT cells regulate the functions of other cell types, but experimental evidence has found NKT cell subsets can modulate the functions of other NKT subsets. Depending on underlying mechanisms, NKT cells can inhibit or exacerbate autoimmunity and malignancy, making them potential targets for disease intervention. NKT cells can respond to foreign and endogenous antigenic glycolipid signals that are expressed during pathogenic invasion or ongoing inflammation, respectively, allowing them to rapidly react to and influence a broad array of diseases. In this article we review the unique development and activation pathways of NKT cells and focus on how these attributes augment or exacerbate autoimmune disorders and malignancy. We also examine the growing evidence that NKT cells are involved in liver inflammatory conditions that can contribute to the development of malignancy. PMID:21995570

The split personality of NKT cells in malignancy, autoimmune and allergic disorders.

Science.gov (United States)

Subleski, Jeff J; Jiang, Qun; Weiss, Jonathan M; Wiltrout, Robert H

2011-10-01

NKT cells are a heterogeneous subset of specialized, self-reactive T cells, with innate and adaptive immune properties, which allow them to bridge innate and adaptive immunity and profoundly influence autoimmune and malignant disease outcomes. NKT cells mediate these activities through their ability to rapidly express pro- and anti-inflammatory cytokines that influence the type and magnitude of the immune response. Not only do NKT cells regulate the functions of other cell types, but experimental evidence has found NKT cell subsets can modulate the functions of other NKT subsets. Depending on underlying mechanisms, NKT cells can inhibit or exacerbate autoimmunity and malignancy, making them potential targets for disease intervention. NKT cells can respond to foreign and endogenous antigenic glycolipid signals that are expressed during pathogenic invasion or ongoing inflammation, respectively, allowing them to rapidly react to and influence a broad array of diseases. In this article we review the unique development and activation pathways of NKT cells and focus on how these attributes augment or exacerbate autoimmune disorders and malignancy. We also examine the growing evidence that NKT cells are involved in liver inflammatory conditions that can contribute to the development of malignancy.

Changes in NK and NKT cells in mesenteric lymph nodes after a Schistosoma japonicum infection.

Science.gov (United States)

Luo, Xueping; Xie, Hongyan; Chen, Dianhui; Yu, Xiuxue; Wu, Fan; Li, Lu; Wu, Changyou; Huang, Jun

2014-03-01

The mesenteric lymph node (MLN) is the main draining lymph node in mouse enterocoelia, which contains many types of immune cells. Among these cells, natural killer (NK) and natural killer T (NKT) cells belong to innate lymphoid cells (ILCs), which have potent activities for controlling a variety of pathogenic infections. In this study, C57BL/6 mice were infected with Schistosoma japonicum for 5-7 weeks. Lymphocytes were isolated from the MLN to detect changes in the phenotype and function of NK and NKT cells using a fluorescence activating cell sorter (FACS). These results demonstrated that a S. japonicum infection could significantly increase the percentage of NK cells in the mouse MLN, (P cell number of both NK and NKT cells. In addition, we found that NK and NKT cells from infected mice expressed higher levels of CD69 compared to normal mice (P NKT cell activation. Moreover, we found that the expression of CD4 was increased in infected MLN NK cells (P NKT cells of infected mice after phorbol 12-myristate 13-acetate (PMA) and ionomycin stimulation (P NKT cells might play roles in modulating the classical T cell response. Finally, our results indicated that the expression of CD94 was decreased in NK cells, suggesting that the downregulation of CD94 expression might served as a mechanism in NK cell activation.

Ex-vivo α-galactosylceramide activation of NKT cells in humans and macaques.

Science.gov (United States)

Fernandez, Caroline S; Cameron, Garth; Godfrey, Dale I; Kent, Stephen J

2012-08-31

NKT cells are key mediators of antiviral and anticancer immunity. Experiments in mice have demonstrated that activation of NKT cells in vivo induces the expression of multiple effector molecules critical to successful immunity. Human clinical trials have shown similar responses, although in vivo activation of NKT cells in humans or primate models are far more limited in number and scope. Measuring ex vivo activation of NKT cells by the CD1d-restricted glycolipid ligand α-Galactosylceramide (α-GalCer) through cytokine expression profiles is a useful marker of NKT cell function, but for reasons that are unclear, this approach does not appear to work as well in humans and non-human primate macaque models in comparison to mice. We performed a series of experiments on human and macaque (Macaca nemestrina) fresh whole blood samples to define optimal conditions to detect NKT cell cytokine (TNF, IFNγ, IL-2) and degranulation marker (CD107a) expression by flow cytometry. We found that conditions previously described for mouse splenocyte NKT cell activation were suboptimal on human or macaque blood NKT cells. In contrast, a 6h incubation with brefeldin A added for the last 4h, in a 96-well plate based assay, and using an α-GalCer concentration of 1 μg/ml were optimal methods to stimulate NKT cells in fresh blood from both humans and macaques. Unexpectedly, we noted that blood NKT cells from macaques infected with SIV were more readily activated by α-GalCer than NKT cells from uninfected macaques, suggesting that SIV infection may have primed the NKT cells. In conclusion, we describe optimized methods for the ex vivo antigen-specific activation of human and macaque blood NKT cells. These assays should be useful in monitoring NKT cells in disease and in immunotherapy studies. Copyright © 2012 Elsevier B.V. All rights reserved.

NKT cells are important mediators of hepatic ischemia-reperfusion injury.

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Richards, James A; Wigmore, Stephen J; Anderton, Stephen M; Howie, Sarah E M

2017-12-01

IRI results from the interruption then reinstatement of an organ's blood supply, and this poses a significant problem in liver transplantation and resectional surgery. In this paper, we explore the role T cells play in the pathogenesis of this injury. We used an in vivo murine model of warm partial hepatic IRI, genetically-modified mice, in vivo antibody depletion, adoptive cell transfer and flow cytometry to determine which lymphocyte subsets contribute to pathology. Injury was assessed by measuring serum alanine aminotransfersase (ALT) and by histological examination of liver tissue sections. The absence of T cells (CD3εKO) is associated with significant protection from injury (p=0.010). Through a strategy of antibody depletion it appears that NKT cells (p=0.0025), rather than conventional T (CD4+ or CD8+) (p=0.11) cells that are the key mediators of injury. Our results indicate that tissue-resident NKT cells, but not other lymphocyte populations are responsible for the injury in hepatic IRI. Targeting the activation of NKT cells and/or their effector apparatus would be a novel approach in protecting the liver during transplantation and resection surgery; this may allow us to expand our current criteria for surgery. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

TET proteins regulate the lineage specification and TCR-mediated expansion of iNKT cells.

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Tsagaratou, Ageliki; González-Avalos, Edahí; Rautio, Sini; Scott-Browne, James P; Togher, Susan; Pastor, William A; Rothenberg, Ellen V; Chavez, Lukas; Lähdesmäki, Harri; Rao, Anjana

2017-01-01

TET proteins oxidize 5-methylcytosine in DNA to 5-hydroxymethylcytosine and other oxidation products. We found that simultaneous deletion of Tet2 and Tet3 in mouse CD4 + CD8 + double-positive thymocytes resulted in dysregulated development and proliferation of invariant natural killer T cells (iNKT cells). Tet2-Tet3 double-knockout (DKO) iNKT cells displayed pronounced skewing toward the NKT17 lineage, with increased DNA methylation and impaired expression of genes encoding the key lineage-specifying factors T-bet and ThPOK. Transfer of purified Tet2-Tet3 DKO iNKT cells into immunocompetent recipient mice resulted in an uncontrolled expansion that was dependent on the nonclassical major histocompatibility complex (MHC) protein CD1d, which presents lipid antigens to iNKT cells. Our data indicate that TET proteins regulate iNKT cell fate by ensuring their proper development and maturation and by suppressing aberrant proliferation mediated by the T cell antigen receptor (TCR).

NKT cell activation by Leishmania mexicana LPG: Description of a novel pathway.

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Zamora-Chimal, Jaime; Fernández-Figueroa, Edith A; Ruiz-Remigio, Adriana; Wilkins-Rodríguez, Arturo A; Delgado-Domínguez, José; Salaiza-Suazo, Norma; Gutiérrez-Kobeh, Laila; Becker, Ingeborg

2017-02-01

NKT cells have been associated with protection against Leishmania donovani, yet their role in infections with Leishmania mexicana has not been addressed, nor has the activation pathway been defined after stimulation with Leishmania mexicana lipophosphoglycan (LPG). We analyzed the activation of NKT cells and their cytokine production in response to Leishmania mexicana LPG. Additionally we compared NKT-cell numbers and cytokine profile in lymph nodes of skin lesions induced by Leishmania mexicana in BALB/c and C57BL/6 mice. We show that LPG activates NKT cells primarily through the indirect pathway, initiating with TLR2 stimulation of dendritic cells (DC), thereby enhancing TLR2, MHC II, and CD86 expressions and IL-12p70 production. This leads to IFN-γ production by NKT cells. C57BL/6 mice showed enhanced DC activation, which correlated with augmented IFN-γ production by NKT cells. Additionally, infected C57BL/6 mice showed elevated percentages of NKT cells with higher IFN-γ and IL-4 production in lymph nodes. We conclude that the response of NKT cells towards Leishmania mexicana LPG initiates with the indirect activation, after binding of LPG to TLR2 in DC. This indirect activation pathway enables NKT cells to produce IFN-γ during the innate phase of Leishmania infection, the magnitude of which differs between mouse strains. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

NKT Cell Subsets Can Exert Opposing Effects in Autoimmunity, Tumor Surveillance and Inflammation

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Viale, Rachael; Ware, Randle; Maricic, Igor; Chaturvedi, Varun; Kumar, Vipin

2014-01-01

The innate-like natural killer T (NKT) cells are essential regulators of immunity. These cells comprise at least two distinct subsets and recognize different lipid antigens presented by the MHC class I like molecules CD1d. The CD1d-dependent recognition pathway of NKT cells is highly conserved from mouse to humans. While most type I NKT cells can recognize αGalCer and express a semi-invariant T cell receptor (TCR), a major population of type II NKT cells reactive to sulfatide utilizes an oligoclonal TCR. Furthermore TCR recognition features of NKT subsets are also distinctive with almost parallel as opposed to perpendicular footprints on the CD1d molecules for the type I and type II NKT cells respectively. Here we present a view based upon the recent studies in different clinical and experimental settings that while type I NKT cells are more often pathogenic, they may also be regulatory. On the other hand, sulfatide-reactive type II NKT cells mostly play an inhibitory role in the control of autoimmune and inflammatory diseases. Since the activity and cytokine secretion profiles of NKT cell subsets can be modulated differently by lipid ligands or their analogs, novel immunotherapeutic strategies are being developed for their differential activation for potential intervention in inflammatory diseases. PMID:25288922

Lysophosphatidic acid generation by pulmonary NKT cell ENPP-2/autotaxin exacerbates hyperoxic lung injury.

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Nowak-Machen, Martina; Lange, Martin; Exley, Mark; Wu, Sherry; Usheva, Anny; Robson, Simon C

2015-12-01

Hyperoxia is still broadly used in clinical practice in order to assure organ oxygenation in critically ill patients, albeit known toxic effects. In this present study, we hypothesize that lysophosphatidic acid (LPA) mediates NKT cell activation in a mouse model of hyperoxic lung injury. In vitro, pulmonary NKT cells were exposed to hyperoxia for 72 h, and the induction of the ectonucleotide pyrophosphatase/phosphodiesterase 2 (ENPP-2) was examined and production of lysophosphatidic acid (LPA) was measured. In vivo, animals were exposed to 100 % oxygen for 72 h and lungs and serum were harvested. Pulmonary NKT cells were then incubated with the LPA antagonist Brp-LPA. Animals received BrP-LPA prior to oxygen exposure. Autotaxin (ATX, ENPP-2) was significantly up-regulated on pulmonary NKT cells after hyperoxia (p NKT cells. LPA levels were significantly reduced by incubating NKT cells with LPA-BrP during oxygen exposure (p NKT cell numbers in vivo. BrP-LPA injection significantly improved survival as well as significantly decreased lung injury and lowered pulmonary NKT cell numbers. We conclude that NKT cell-induced hyperoxic lung injury is mediated by pro-inflammatory LPA generation, at least in part, secondary to ENPP-2 up-regulation on pulmonary NKT cells. Being a potent LPA antagonist, BrP-LPA prevents hyperoxia-induced lung injury in vitro and in vivo.

Generation of induced pluripotent stem cell-derived mice by reprogramming of a mature NKT cell.

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Ren, Yue; Dashtsoodol, Nyambayar; Watarai, Hiroshi; Koseki, Haruhiko; Quan, Chengshi; Taniguchi, Masaru

2014-10-01

NKT cells are characterized by their expression of an NKT-cell-specific invariant antigen-receptor α chain encoded by Vα14Jα18 gene segments. These NKT cells bridge the innate and acquired immune systems to mediate effective and augmented responses; however, the limited number of NKT cells in vivo hampers their analysis. Here, two lines of induced pluripotent stem cell-derived mice (NKT-iPSC-derived mice) were generated by reprogramming of mature NKT cells, where one harbors both rearranged Vα14Jα18 and Vβ7 genes and the other carries rearranged Vα14Jα18 on both alleles but germline Vβ loci. The analysis of NKT-iPSC-derived mice showed a significant increase in NKT cell numbers with relatively normal frequencies of functional subsets, but significantly enhanced in some cases, and acquired functional NKT cell maturation in peripheral lymphoid organs. NKT-iPSC-derived mice also showed normal development of other immune cells except for the absence of γδT cells and disturbed development of conventional CD4 αβT cells. These results suggest that the NKT-iPSC-derived mice are a better model for NKT cell development and function study rather than transgenic mouse models reported previously and also that the presence of a pre-rearranged Vα14Jα18 in the natural chromosomal context favors the developmental fate of NKT cells. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society for Immunology.

Pro-inflammatory activated Kupffer cells by lipids induce hepatic NKT cells deficiency through activation-induced cell death.

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Tongfang Tang

Full Text Available BACKGROUND: Dietary lipids play an important role in the progression of non-alcoholic fatty liver disease (NAFLD through alternation of liver innate immune response. AIMS: The present study was to investigate the effect of lipid on Kupffer cells phenotype and function in vivo and in vitro. And further to investigate the impact of lipid on ability of Kupffer cell lipid antigen presentation to activate NKT cells. METHODS: Wild type male C57BL/6 mice were fed either normal or high-fat diet. Hepatic steatosis, Kupffer cell abundance, NKT cell number and cytokine gene expression were evaluated. Antigen presentation assay was performed with Kupffer cells treated with certain fatty acids in vitro and co-cultured with NKT cells. RESULTS: High-fat diet induced hepatosteatosis, significantly increased Kupffer cells and decreased hepatic NKT cells. Lipid treatment in vivo or in vitro induced increase of pro-inflammatory cytokines gene expression and toll-like receptor 4 (TLR4 expression in Kupffer cells. Kupffer cells expressed high levels of CD1d on cell surface and only presented exogenous lipid antigen to activate NKT cells. Ability of Kupffer cells to present antigen and activate NKT cells was enhanced after lipid treatment. In addition, pro-inflammatory activated Kupffer cells by lipid treatment induced hepatic NKT cells activation-induced apoptosis and necrosis. CONCLUSION: High-fat diet increase Kupffer cells number and induce their pro-inflammatory status. Pro-inflammatory activated Kupfffer cells by lipid promote hepatic NKT cell over-activation and cell death, which lead to further hepatic NKT cell deficiency in the development of NAFLD.

Pro-inflammatory activated Kupffer cells by lipids induce hepatic NKT cells deficiency through activation-induced cell death.

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Tang, Tongfang; Sui, Yongheng; Lian, Min; Li, Zhiping; Hua, Jing

2013-01-01

Dietary lipids play an important role in the progression of non-alcoholic fatty liver disease (NAFLD) through alternation of liver innate immune response. The present study was to investigate the effect of lipid on Kupffer cells phenotype and function in vivo and in vitro. And further to investigate the impact of lipid on ability of Kupffer cell lipid antigen presentation to activate NKT cells. Wild type male C57BL/6 mice were fed either normal or high-fat diet. Hepatic steatosis, Kupffer cell abundance, NKT cell number and cytokine gene expression were evaluated. Antigen presentation assay was performed with Kupffer cells treated with certain fatty acids in vitro and co-cultured with NKT cells. High-fat diet induced hepatosteatosis, significantly increased Kupffer cells and decreased hepatic NKT cells. Lipid treatment in vivo or in vitro induced increase of pro-inflammatory cytokines gene expression and toll-like receptor 4 (TLR4) expression in Kupffer cells. Kupffer cells expressed high levels of CD1d on cell surface and only presented exogenous lipid antigen to activate NKT cells. Ability of Kupffer cells to present antigen and activate NKT cells was enhanced after lipid treatment. In addition, pro-inflammatory activated Kupffer cells by lipid treatment induced hepatic NKT cells activation-induced apoptosis and necrosis. High-fat diet increase Kupffer cells number and induce their pro-inflammatory status. Pro-inflammatory activated Kupfffer cells by lipid promote hepatic NKT cell over-activation and cell death, which lead to further hepatic NKT cell deficiency in the development of NAFLD.

A mutation within the SH2 domain of slp-76 regulates the tissue distribution and cytokine production of iNKT cells in mice.

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Danzer, Claudia; Koller, Anna; Baier, Julia; Arnold, Harald; Giessler, Claudia; Opoka, Robert; Schmidt, Stephanie; Willers, Maike; Mihai, Sidonia; Parsch, Hans; Wirtz, Stefan; Daniel, Christoph; Reinhold, Annegret; Engelmann, Swen; Kliche, Stefanie; Bogdan, Christian; Hoebe, Kasper; Mattner, Jochen

2016-09-01

TCR ligation is critical for the selection, activation, and integrin expression of T lymphocytes. Here, we explored the role of the TCR adaptor protein slp-76 on iNKT-cell biology. Compared to B6 controls, slp-76(ace/ace) mice carrying a missense mutation (Thr428Ile) within the SH2-domain of slp-76 showed an increase in iNKT cells in the thymus and lymph nodes, but a decrease in iNKT cells in spleens and livers, along with reduced ADAP expression and cytokine response. A comparable reduction in iNKT cells was observed in the livers and spleens of ADAP-deficient mice. Like ADAP(-/-) iNKT cells, slp-76(ace/ace) iNKT cells were characterized by enhanced CD11b expression, correlating with an impaired induction of the TCR immediate-early gene Nur77 and a decreased adhesion to ICAM-1. Furthermore, CD11b-intrinsic effects inhibited cytokine release, concanavalin A-mediated inflammation, and iNKT-cell accumulation in the liver. Unlike B6 and ADAP(-/-) mice, the expression of the transcription factors Id3 and PLZF was reduced, whereas NP-1-expression was enhanced in slp-76(ace/ace) mice. Blockade of NP-1 decreased the recovery of iNKT cells from peripheral lymph nodes, identifying NP-1 as an iNKT-cell-specific adhesion factor. Thus, slp-76 contributes to the regulation of the tissue distribution, PLZF, and cytokine expression of iNKT cells via ADAP-dependent and -independent mechanisms. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tolerogenic interactions between CD8+ dendritic cells and NKT cells prevent rejection of bone marrow and organ grafts.

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Hongo, David; Tang, Xiaobin; Zhang, Xiangyue; Engleman, Edgar G; Strober, Samuel

2017-03-23

The combination of total lymphoid irradiation and anti-T-cell antibodies safely induces immune tolerance to combined hematopoietic cell and organ allografts in humans. Our mouse model required host natural killer T (NKT) cells to induce tolerance. Because NKT cells normally depend on signals from CD8 + dendritic cells (DCs) for their activation, we used the mouse model to test the hypothesis that, after lymphoid irradiation, host CD8 + DCs play a requisite role in tolerance induction through interactions with NKT cells. Selective deficiency of either CD8 + DCs or NKT cells abrogated chimerism and organ graft acceptance. After radiation, the CD8 + DCs increased expression of surface molecules required for NKT and apoptotic cell interactions and developed suppressive immune functions, including production of indoleamine 2,3-deoxygenase. Injection of naive mice with apoptotic spleen cells generated by irradiation led to DC changes similar to those induced by lymphoid radiation, suggesting that apoptotic body ingestion by CD8 + DCs initiates tolerance induction. Tolerogenic CD8 + DCs induced the development of tolerogenic NKT cells with a marked T helper 2 cell bias that, in turn, regulated the differentiation of the DCs and suppressed rejection of the transplants. Thus, reciprocal interactions between CD8 + DCs and invariant NKT cells are required for tolerance induction in this system that was translated into a successful clinical protocol. © 2017 by The American Society of Hematology.

Migration and chemokine receptor pattern of colitis-preventing DX5+NKT cells.

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Hornung, Matthias; Werner, Jens M; Farkas, Stefan; Schlitt, Hans J; Geissler, Edward K

2011-11-01

DX5(+)NKT cells are a subpopulation of NKT cells expressing both T cell receptor and NK cell markers that show an immune-regulating function. Transferred DX5(+)NKT cells from immune competent Balb/c mice can prevent or reduce induced colitis in severe combined immunodeficient (SCID) mice. Here, we investigated the in vivo migration of DX5(+)NKT cells and their corresponding chemokine receptor patterns. DX5(+)NKT cells were isolated from spleens of Balb/c mice and transferred into Balb/c SCID mice. After 2 and 8 days, in vivo migration was examined using in vivo microscopy. In addition, the chemokine receptor pattern was analyzed with fluorescence-activated cell sorting (FACS) and the migration assay was performed. Our results show that labeled DX5(+)NKT cells were primarily detectable in mesenteric lymph nodes and spleen after transfer. After 8 days, DX5(+)NKT cells were observed in the colonic tissues, especially the appendix. FACS analysis of chemokine receptors in DX5(+)NKT cells revealed expression of CCR3, CCR6, CCR9, CXCR3, CXCR4, and CXCR6, but no CCR5, CXCR5, or the lymphoid homing receptor CCR7. Stimulation upregulated especially CCR7 expression, and chemokine receptor patterns were different between splenic and liver DX5(+)NKT cells. These data indicate that colitis-preventing DX5(+)NKT cells need to traffic through lymphoid organs to execute their immunological function at the site of inflammation. Furthermore, DX5(+)NKT cells express a specific chemokine receptor pattern with an upregulation of the lymphoid homing receptor CCR7 after activation.

Mycobacterium tuberculosis-specific memory NKT cells in patients with tuberculous pleurisy.

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Li, Zitao; Yang, Binyan; Zhang, Yannan; Ma, Jiangjun; Chen, Xinchun; Lao, Suihua; Li, Baiqing; Wu, Changyou

2014-11-01

Natural killer T (NKT) cells from mouse and human play a protective role in the immune responses against the infection of Mycobacterium tuberculosis. However, the characteristic of CD3(+)TCRvβ11(+) NKT cells at the local site of M. tuberculosis infection remains poorly defined. In the present study, we found that the numbers of CD3(+)TCRvβ11(+) NKT cells in pleural fluid mononuclear cells (PFMCs) were significantly lower than those in peripheral blood mononuclear cells (PBMCs). However, CD3(+)TCRvβ11(+) NKT cells from PFMCs spontaneously expressed high levels of CD69 and CD25 and effector memory phenotypes of CD45RO(high)CD62L(low)CCR7(low). After stimulation with the antigens of M. tuberculosis, CD3(+)TCRvβ11(+) NKT cells from PFMCs produced high levels of IFN-γ. Sorted CD3(+)TCRvβ11(+) NKT cells from PFMCs cultured with antigen presenting cells (APCs) produced IFN-γ protein and mRNA. The production of IFN-γ could be completely inhibited by AG490 and Wortmannin. In addition, CD3(+)TCRvβ11(+) NKT cells from PFMCs expressed higher levels of Fas (CD95), FasL (CD178) and perforin but lower levels of granzyme B compared with those from PBMCs. Taken together, our data demonstrated for the first time that M. tuberculosis-specific CD3(+)TCRvβ11(+) NKT cells participated in the local immune responses against M. tuberculosis through the production of IFN-γ and the secretion of cytolytic molecules.

An update on the mouse liver proteome

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Borlak Jürgen

2009-09-01

Full Text Available Abstract Background Decoding of the liver proteome is subject of intense research, but hampered by methodological constraints. We recently developed an improved protocol for studying rat liver proteins based on 2-DE-MALDI-TOF-MS peptide mass finger printing. This methodology was now applied to develop a mouse liver protein database. Results Liver proteins were extracted by two different lysis buffers in sequence followed by a liquid-phase IEF pre-fractionation and separation of proteins by 2 DE at two different pH ranges, notably 5-8 and 7-10. Based on 9600 in gel digests a total of 643 mouse liver proteins with high sequence coverage (> 20 peptides per protein could be identified by MALDI-TOF-MS peptide mass finger printing. Notably, 255 proteins are novel and have not been reported so far by conventional two-dimensional electrophoresis proteome mapping. Additionally, the results of the present findings for mouse liver were compared to published data of the rat proteome to compile as many proteins as possible in a rodent liver database. Conclusion Based on 2-DE MALDI-TOF-MS a significantly improved proteome map of mouse liver was obtained. We discuss some prominent members of newly identified proteins for a better understanding of liver biology.

Immunologic glycosphingolipidomics and NKT cell development in mouse thymus

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Li, Yunsen; Thapa, Prakash; Hawke, David

2009-01-01

Invariant NKT cells are a hybrid cell type of Natural Killer cells and T cells, whose development is dependent on thymic positive selection mediated by double positive thymocytes through their recognition of natural ligands presented by CD1d, a nonpolymorphic, non-MHC, MHC-like antigen presenting...

Natural killer T (NKT cells accelerate Shiga toxin type 2 (Stx2 pathology in mice

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Fumiko eObata

2015-04-01

Full Text Available Shiga toxin-producing Escherichia coli (STEC is a leading cause of childhood renal disease He-molytic Uremic Syndrome (HUS. The involvement of renal cytokines and chemokines is sus-pected to play a critical role in disease progression. In current article, we tested the hypothesis that NKT cells are involved in Stx2-induced pathology in vivo. To address this hypothesis we compared Stx2 toxicity in WT and CD1 knockout (KO mice. In CD1KO mice, which lack nat-ural killer T (NKT cells, Stx2-induced pathologies such as weight loss, renal failure, and death were delayed. In WT mice, Stx2-specific selective increase in urinary albumin occurs in later time points, and this was also delayed in NKT cell deficient mice. NKT cell-associated cytokines such as IL-2, IL-4, IFN-γ and IL-17 were detected in kidney lysates of Stx2-injected WT mice with the peak around 36 h after Stx2 injection. In CD1KO, there was a delay in the kinetics, and increases in these cytokines were observed 60 h post Stx2 injection. These data suggest that NKT cells accelerate Stx2-induced pathology in mouse kidneys. To determine the mechanism by which NKT cells promote Stx2-associated disease, in vitro studies were performed using murine renal cells. We found that murine glomerular endothelial cells and podocytes express functional CD1d molecules and can present exogenous antigen to NKT cells. Moreover, we observed the direct interaction between Stx2 and the receptor Gb3 on the surface of mouse renal cells by 3D STORM-TIRF which provides single molecule imaging. Collectively, these data suggest that Stx2 binds to Gb3 on renal cells and leads to aberrant CD1d-mediated NKT cell activation. Therefore, strategies targeting NKT cells could have a significant impact on Stx2-associated renal pathology in STEC disease.

Natural killer T (NKT) cells accelerate Shiga toxin type 2 (Stx2) pathology in mice.

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Obata, Fumiko; Subrahmanyam, Priyanka B; Vozenilek, Aimee E; Hippler, Lauren M; Jeffers, Tynae; Tongsuk, Methinee; Tiper, Irina; Saha, Progyaparamita; Jandhyala, Dakshina M; Kolling, Glynis L; Latinovic, Olga; Webb, Tonya J

2015-01-01

Shiga toxin-producing Escherichia coli (STEC) is a leading cause of childhood renal disease Hemolytic Uremic Syndrome (HUS). The involvement of renal cytokines and chemokines is suspected to play a critical role in disease progression. In current article, we tested the hypothesis that NKT cells are involved in Stx2-induced pathology in vivo. To address this hypothesis we compared Stx2 toxicity in WT and CD1 knockout (KO) mice. In CD1KO mice, which lack natural killer T (NKT) cells, Stx2-induced pathologies such as weight loss, renal failure, and death were delayed. In WT mice, Stx2-specific selective increase in urinary albumin occurs in later time points, and this was also delayed in NKT cell deficient mice. NKT cell-associated cytokines such as IL-2, IL-4, IFN-γ, and IL-17 were detected in kidney lysates of Stx2-injected WT mice with the peak around 36 h after Stx2 injection. In CD1KO, there was a delay in the kinetics, and increases in these cytokines were observed 60 h post Stx2 injection. These data suggest that NKT cells accelerate Stx2-induced pathology in mouse kidneys. To determine the mechanism by which NKT cells promote Stx2-associated disease, in vitro studies were performed using murine renal cells. We found that murine glomerular endothelial cells and podocytes express functional CD1d molecules and can present exogenous antigen to NKT cells. Moreover, we observed the direct interaction between Stx2 and the receptor Gb3 on the surface of mouse renal cells by 3D STORM-TIRF which provides single molecule imaging. Collectively, these data suggest that Stx2 binds to Gb3 on renal cells and leads to aberrant CD1d-mediated NKT cell activation. Therefore, strategies targeting NKT cells could have a significant impact on Stx2-associated renal pathology in STEC disease.

Mice lacking NKT cells but with a complete complement of CD8+ T-cells are not protected against the metabolic abnormalities of diet-induced obesity.

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Benjamin S Mantell

Full Text Available The contribution of natural killer T (NKT cells to the pathogenesis of metabolic abnormalities of obesity is controversial. While the combined genetic deletion of NKT and CD8(+ T-cells improves glucose tolerance and reduces inflammation, interpretation of these data have been complicated by the recent observation that the deletion of CD8(+ T-cells alone reduces obesity-induced inflammation and metabolic dysregulation, leaving the issue of the metabolic effects of NKT cell depletion unresolved. To address this question, CD1d null mice (CD1d(-/-, which lack NKT cells but have a full complement of CD8(+ T-cells, and littermate wild type controls (WT on a pure C57BL/6J background were exposed to a high fat diet, and glucose intolerance, insulin resistance, dyslipidemia, inflammation, and obesity were assessed. Food intake (15.5±4.3 vs 15.3±1.8 kcal/mouse/day, weight gain (21.8±1.8 vs 22.8±1.4 g and fat mass (18.6±1.9 vs 19.5±2.1 g were similar in CD1d(-/- and WT, respectively. As would be expected from these data, metabolic rate (3.0±0.1 vs 2.9±0.2 ml O(2/g/h and activity (21.6±4.3 vs 18.5±2.6 beam breaks/min were unchanged by NKT cell depletion. Furthermore, the degree of insulin resistance, glucose intolerance, liver steatosis, and adipose and liver inflammatory marker expression (TNFα, IL-6, IL-10, IFN-γ, MCP-1, MIP1α induced by high fat feeding in CD1d(-/- were not different from WT. We conclude that deletion of NKT cells, in the absence of alterations in the CD8(+ T-cell population, is insufficient to protect against the development of the metabolic abnormalities of diet-induced obesity.

The transcription factor Th-POK negatively regulates Th17 differentiation in Vα14i NKT cells

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Engel, Isaac; Zhao, Meng; Kappes, Dietmar; Taniuchi, Ichiro

2012-01-01

The majority of mouse Vα14 invariant natural killer T (Vα14i NKT) cells produce several cytokines, including IFNγ and IL-4, very rapidly after activation. A subset of these cells, known as NKT17 cells, however, differentiates in the thymus to preferentially produce IL-17. Here, we show that the transcription factor—known as T helper, Poxviruses, and Zinc-finger and Krüppel family, (Th-POK)—represses the formation of NKT17 cells. Vα14i NKT cells from Th-POK–mutant helper deficient (hd/hd) mice have increased transcripts of genes normally expressed by Th17 and NKT17 cells, and even heterozygosity for this mutation leads to dramatically increased numbers of Vα14i NKT cells that are poised to express IL-17, especially in the thymus and lymph nodes. In addition, using gene reporter mice, we demonstrate that NKT17 cells from wild-type mice express lower amounts of Th-POK than the majority population of Vα14i NKT cells. We also show that retroviral transduction of Th-POK represses the expression of the Th17 master regulator RORγT in Vα14i NKT-cell lines. Our data suggest that NKT17-cell differentiation is intrinsically regulated by Th-POK activity, with only low levels of Th-POK permissive for the differentiation of NKT17 cells. PMID:23034280

Distinct requirements for activation of NKT and NK cells during viral infection.

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Tyznik, Aaron J; Verma, Shilpi; Wang, Qiao; Kronenberg, Mitchell; Benedict, Chris A

2014-04-15

NK cells are key regulators of innate defense against mouse CMV (MCMV). Like NK cells, NKT cells also produce high levels of IFN-γ rapidly after MCMV infection. However, whether similar mechanisms govern activation of these two cell types, as well as the significance of NKT cells for host resistance, remain unknown. In this article, we show that, although both NKT and NK cells are activated via cytokines, their particular cytokine requirements differ significantly in vitro and in vivo. IL-12 is required for NKT cell activation in vitro but is not sufficient, whereas NK cells have the capacity to be activated more promiscuously in response to individual cytokines from innate cells. In line with these results, GM-CSF-derived dendritic cells activated only NK cells upon MCMV infection, consistent with their virtual lack of IL-12 production, whereas Flt3 ligand-derived dendritic cells produced IL-12 and activated both NK and NKT cells. In vivo, NKT cell activation was abolished in IL-12(-/-) mice infected with MCMV, whereas NK cells were still activated. In turn, splenic NK cell activation was more IL-18 dependent. The differential requirements for IL-12 and IL-18 correlated with the levels of cytokine receptor expression by NK and NKT cells. Finally, mice lacking NKT cells showed reduced control of MCMV, and depleting NK cells further enhanced viral replication. Taken together, our results show that NKT and NK cells have differing requirements for cytokine-mediated activation, and both can contribute nonredundantly to MCMV defense, revealing that these two innate lymphocyte subsets function together to fine-tune antiviral responses.

Reactive Oxygen Species Regulate the Inflammatory Function of NKT Cells through Promyelocytic Leukemia Zinc Finger.

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Kim, Yeung-Hyen; Kumar, Ajay; Chang, Cheong-Hee; Pyaram, Kalyani

2017-11-15

Reactive oxygen species (ROS) are byproducts of aerobic metabolism and contribute to both physiological and pathological conditions as second messengers. ROS are essential for activation of T cells, but how ROS influence NKT cells is unknown. In the present study, we investigated the role of ROS in NKT cell function. We found that NKT cells, but not CD4 or CD8 T cells, have dramatically high ROS in the spleen and liver of mice but not in the thymus or adipose tissues. Accordingly, ROS-high NKT cells exhibited increased susceptibility and apoptotic cell death with oxidative stress. High ROS in the peripheral NKT cells were primarily produced by NADPH oxidases and not mitochondria. We observed that sorted ROS-high NKT cells were enriched in NKT1 and NKT17 cells, whereas NKT2 cells were dominant in ROS-low cells. Furthermore, treatment of NKT cells with antioxidants led to reduced frequencies of IFN-γ- and IL-17-expressing cells, indicating that ROS play a role in regulating the inflammatory function of NKT cells. The transcription factor promyelocytic leukemia zinc finger (PLZF) seemed to control the ROS levels. NKT cells from adipose tissues that do not express PLZF and those from PLZF haplodeficient mice have low ROS. Conversely, ROS were highly elevated in CD4 T cells from mice ectopically expressing PLZF. Thus, our findings demonstrate that PLZF controls ROS levels, which in turn governs the inflammatory function of NKT cells. Copyright © 2017 by The American Association of Immunologists, Inc.

Interleukin-30 (IL27p28) alleviates experimental sepsis by modulating cytokine profile in NKT cells.

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Yan, Jun; Mitra, Abhisek; Hu, Jiemiao; Cutrera, Jeffery J; Xia, Xueqing; Doetschman, Thomas; Gagea, Mihai; Mishra, Lopa; Li, Shulin

2016-05-01

Sepsis is an acute systemic inflammatory response to infection associated with high patient mortality (28-40%). We hypothesized that interleukin (IL)-30, a novel cytokine protecting mice against liver injury resulting from inflammation, would generate a protective effect against systemic inflammation and sepsis-induced death. Sepsis was induced by lipopolysaccharide (LPS) or cecal ligation and puncture (CLP). The inhibitory effects of IL-30 on septic inflammation and associated therapeutic effects were determined in wild-type, IL30 (p28)(-/-), IL10(-/-), and CD1d(-/-) mice. Mice treated with pIL30 gene therapy or recombinant IL-30 protein (rIL30) were protected from LPS-induced septic shock or CLP-induced polymicrobial sepsis and showed markedly less liver damage and lymphocyte apoptosis than control septic mice. The resulting reduction in mortality was mediated through attenuation of the systemic pro-inflammatory response and augmentation of bacterial clearance. Mice lacking IL-30 were more sensitive to LPS-induced sepsis. Natural killer-like T cells (NKT) produced much higher levels of IL-10 and lower levels of interferon-gamma and tumor necrosis factor-alpha in IL-30-treated septic mice than in control septic mice. Likewise, deficiency in IL-10 or NKT cells abolished the protective role of IL-30 against sepsis. Furthermore, IL-30 induced IL-10 production in purified and LPS-stimulated NKT cells. Blocking IL-6R or gp130 inhibited IL-30 mediated IL-10 production. IL-30 is important in modulating production of NKT cytokines and subsequent NKT cell-mediated immune regulation of other cells. Therefore, IL-30 has a role in prevention and treatment of sepsis via modulation of cytokine production by NKT. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Discrete functions of mTOR signaling in iNKT cell development and NKT17 fate decision

OpenAIRE

Wei, Jun; Yang, Kai; Chi, Hongbo

2014-01-01

Invariant natural killer T (iNKT) cells have been recently classified into NKT1, NKT2 and NKT17 lineages with distinct transcription factor and cytokine profiles, but mechanisms underlying such fate decisions remain elusive. Here, we report crucial roles of mTOR signaling especially mTORC2 in iNKT cell development and fate determination of NKT17 cells. Loss of Rictor, an obligatory component of mTORC2, decreased thymic and peripheral iNKT cells, associated with defective survival. Strikingly,...

TLR4 and NKT cell synergy in immunotherapy against visceral leishmaniasis.

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Subir Karmakar

Full Text Available NKT cells play an important role in autoimmune diseases, tumor surveillance, and infectious diseases, providing in most cases protection against infection. NKT cells are reactive to CD1d presented glycolipid antigens. They can modulate immune responses by promoting the secretion of type 1, type 2, or immune regulatory cytokines. Pathogen-derived signals to dendritic cells mediated via Toll like Receptors (TLR can be modulated by activated invariant Natural Killer T (iNKT cells. The terminal β-(1-4-galactose residues of glycans can modulate host responsiveness in a T helper type-1 direction via IFN-γ and TLRs. We have attempted to develop a defined immunotherapeutic, based on the cooperative action of a TLR ligand and iNKT cell using a mouse model of visceral leishmaniasis. We evaluated the anti-Leishmania immune responses and the protective efficacy of the β-(1-4-galactose terminal NKT cell ligand glycosphingophospholipid (GSPL antigen of L. donovani parasites. Our results suggest that TLR4 can function as an upstream sensor for GSPL and provoke intracellular inflammatory signaling necessary for parasite killing. Treatment with GSPL was able to induce a strong effective T cell response that contributed to effective control of acute parasite burden and led to undetectable parasite persistence in the infected animals. These studies for the first time demonstrate the interactions between a TLR ligand and iNKT cell activation in visceral leishmaniasis immunotherapeutic.

The preventive role of type 2 NKT cells in the development of type 1 diabetes.

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Sørensen, Jakob Ørskov; Buschard, Karsten; Brogren, Carl-Henrik

2014-03-01

In the last two decades, natural killer T (NKT) cells have emerged as an important factor in preventing type 1 diabetes (T1D) when investigated in the experimental non-obese diabetic (NOD) mouse model. So far, investigations have largely focused on type 1 NKT cells with invariant T-cell receptors, whereas the role of type 2 NKT cells with diverse T-cell receptors is less well understood. However, there have been several findings which indicate that in fact type 2 NKT cells may regulate the progression of type 1 diabetes in NOD mice, including a fraction of these cells which recognize β-cell-enriched sulfatide. Therefore, the focus for this review is to present the current evidence of the effect of type 2 NKT cells on the development of T1D. In general, there is still uncertainty surrounding the mechanism of activation and function of NKT cells. Here, we present two models of the effector mechanisms, respectively, Th1/Th2 polarization and the induction of tolerogenic dendritic cells (DC). In conclusion, this review points to the importance of immunoregulation by type 2 NKT cells in preventing the development of T1D and highlights the induction of tolerogenic DC as a likely mechanism. The possible therapeutic role of type 1 and type 2 NKT cells are evaluated and future experiments concerning type 2 NKT cells and T1D are proposed. © 2013 APMIS. Published by John Wiley & Sons Ltd.

Components of Streptococcus pneumoniae suppress allergic airways disease and NKT cells by inducing regulatory T cells.

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Thorburn, Alison N; Foster, Paul S; Gibson, Peter G; Hansbro, Philip M

2012-05-01

Asthma is an allergic airways disease (AAD) caused by dysregulated immune responses and characterized by eosinophilic inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR). NKT cells have been shown to contribute to AHR in some mouse models. Conversely, regulatory T cells (Tregs) control aberrant immune responses and maintain homeostasis. Recent evidence suggests that Streptococcus pneumoniae induces Tregs that have potential to be harnessed therapeutically for asthma. In this study, mouse models of AAD were used to identify the S. pneumoniae components that have suppressive properties, and the mechanisms underlying suppression were investigated. We tested the suppressive capacity of type-3-polysaccharide (T3P), isolated cell walls, pneumolysoid (Ply) and CpG. When coadministered, T3P + Ply suppressed the development of: eosinophilic inflammation, Th2 cytokine release, mucus hypersecretion, and AHR. Importantly, T3P + Ply also attenuated features of AAD when administered during established disease. We show that NKT cells contributed to the development of AAD and also were suppressed by T3P + Ply treatment. Furthermore, adoptive transfer of NKT cells induced AHR, which also could be reversed by T3P + Ply. T3P + Ply-induced Tregs were essential for the suppression of NKT cells and AAD, which was demonstrated by Treg depletion. Collectively, our results show that the S. pneumoniae components T3P + Ply suppress AAD through the induction of Tregs that blocked the activity of NKT cells. These data suggest that S. pneumoniae components may have potential as a therapeutic strategy for the suppression of allergic asthma through the induction of Tregs and suppression of NKT cells.

Downregulation of BTLA on NKT Cells Promotes Tumor Immune Control in a Mouse Model of Mammary Carcinoma.

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Sekar, Divya; Govene, Luisa; Del Río, María-Luisa; Sirait-Fischer, Evelyn; Fink, Annika F; Brüne, Bernhard; Rodriguez-Barbosa, José I; Weigert, Andreas

2018-03-07

Natural Killer T cells (NKT cells) are emerging as critical regulators of pro- and anti-tumor immunity, both at baseline and in therapeutic settings. While type I NKT cells can promote anti-tumor immunity, their activity in the tumor microenvironment may be limited by negative regulators such as inhibitory immune checkpoints. We observed dominant expression of B- and T-lymphocyte attenuator (BTLA) on type I NKT cells in polyoma middle T oncogene-driven (PyMT) murine autochthonous mammary tumors. Other immune checkpoint receptors, such as programmed cell death 1 (PD-1) were equally distributed among T cell populations. Interference with BTLA using neutralizing antibodies limited tumor growth and pulmonary metastasis in the PyMT model in a therapeutic setting, correlating with an increase in type I NKT cells and expression of cytotoxic marker genes. While therapeutic application of an anti-PD-1 antibody increased the number of CD8+ cytotoxic T cells and elevated IL-12 expression, tumor control was not established. Expression of ZBTB16, the lineage-determining transcription factor of type I NKT cells, was correlated with a favorable patient prognosis in the METABRIC dataset, and BTLA levels were instrumental to further distinguish prognosis in patents with high ZBTB16 expression. Taken together, these data support a role of BTLA on type I NKT cells in limiting anti-tumor immunity.

Downregulation of BTLA on NKT Cells Promotes Tumor Immune Control in a Mouse Model of Mammary Carcinoma

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Divya Sekar

2018-03-01

Full Text Available Natural Killer T cells (NKT cells are emerging as critical regulators of pro- and anti-tumor immunity, both at baseline and in therapeutic settings. While type I NKT cells can promote anti-tumor immunity, their activity in the tumor microenvironment may be limited by negative regulators such as inhibitory immune checkpoints. We observed dominant expression of B- and T-lymphocyte attenuator (BTLA on type I NKT cells in polyoma middle T oncogene-driven (PyMT murine autochthonous mammary tumors. Other immune checkpoint receptors, such as programmed cell death 1 (PD-1 were equally distributed among T cell populations. Interference with BTLA using neutralizing antibodies limited tumor growth and pulmonary metastasis in the PyMT model in a therapeutic setting, correlating with an increase in type I NKT cells and expression of cytotoxic marker genes. While therapeutic application of an anti-PD-1 antibody increased the number of CD8+ cytotoxic T cells and elevated IL-12 expression, tumor control was not established. Expression of ZBTB16, the lineage-determining transcription factor of type I NKT cells, was correlated with a favorable patient prognosis in the METABRIC dataset, and BTLA levels were instrumental to further distinguish prognosis in patents with high ZBTB16 expression. Taken together, these data support a role of BTLA on type I NKT cells in limiting anti-tumor immunity.

The Functions of Type I and Type II Natural Killer T (NKT) Cells in Inflammatory Bowel Diseases

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Liao, Chia-Min; Zimmer, Michael I.; Wang, Chyung-Ru

2013-01-01

CD1d-restricted natural killer T (NKT) cells are a distinct subset of T cells that rapidly produce an array of cytokines upon activation and play a critical role in regulating various immune responses. NKT cells are classified into two groups based on differences in T cell receptor (TCR) usage. Type I NKT cells have an invariant TCRα-chain and are readily detectable by α-galactosylceramide (α-GalCer)-loaded CD1d tetramers. Type II NKT cells have a more diverse TCR repertoire and cannot be directly identified. Both types of NKT cells as well as multiple CD1d-expressing cell types are present in the intestine and their interactions are likely to be modulated by pathogenic and commensal microbes, which in turn contribute to the intestinal immune responses in health and disease. Indeed, in several animal models of inflammatory bowel disease (IBD), Type I NKT cells have been shown to make both protective and pathogenic contributions to disease. In contrast, in human patients suffering from ulcerative colitis (UC), and a mouse model in which both CD1d expression and the frequency of Type II NKT cells are increased, Type II NKT cells appear to promote intestinal inflammation. In this review, we summarize present knowledge on the antigen recognition, activation and function of NKT cells with a particular focus on their role in IBD, and discuss factors that may influence the functional outcome of NKT cell responses in intestinal inflammation. PMID:23518808

CD28 controls the development of innate-like CD8+ T cells by promoting the functional maturation of NKT cells.

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Yousefi, Mitra; Duplay, Pascale

2013-11-01

NK T cells(NKT cells) share functional characteristics and homing properties that are distinct from conventional T cells. In this study, we investigated the contribution of CD28 in the functional development of γδ NKT and αβ NKT cells in mice. We show that CD28 promotes the thymic maturation of promyelocytic leukemia zinc finger(+) IL-4(+) NKT cells and upregulation of LFA-1 expression on NKT cells. We demonstrate that the developmental defect of γδ NKT cells in CD28-deficient mice is cell autonomous. Moreover, we show in both wild-type C57BL/6 mice and in downstream of tyrosine kinase-1 transgenic mice, a mouse model with increased numbers of γδ NKT cells, that CD28-mediated regulation of thymic IL-4(+) NKT cells promotes the differentiation of eomesodermin(+) CD44(high) innate-like CD8(+) T cells. These findings reveal a previously unappreciated mechanism by which CD28 controls NKT-cell homeostasis and the size of the innate-like CD8(+) T-cell pool. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

NKAP regulates iNKT cell proliferation and differentiation into ROR-��t expressing NKT17 cells

OpenAIRE

Thapa, Puspa; Chen, Meibo W.; McWilliams, Douglas C.; Belmonte, Paul; Constans, Megan; Sant���Angelo, Derek B.; Shapiro, Virginia Smith

2016-01-01

Invariant Natural Killer T (iNKT) cells are a unique lineage with characteristics of both adaptive and innate lymphocytes, and recognize glycolipid presented by an MHC Class I-like CD1d molecule. During thymic development, iNKT cells also differentiate into NKT1, NKT2 and NKT17 functional subsets that preferentially produce cytokines IFN-��, IL-4 and IL-17, respectively, upon activation. Newly selected iNKT cells undergo a burst of proliferation, which is defective in mice with a specific del...

Liver Transplantation in the Mouse: Insights Into Liver Immunobiology, Tissue Injury and Allograft Tolerance

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Yokota, Shinichiro; Yoshida, Osamu; Ono, Yoshihiro; Geller, David A.; Thomson, Angus W.

2016-01-01

The surgically-demanding mouse orthotopic liver transplant model was first described in 1991. It has proved a powerful research tool for investigation of liver biology, tissue injury, the regulation of alloimmunity and tolerance induction and the pathogenesis of specific liver diseases. Liver transplantation in mice has unique advantages over transplantation of the liver in larger species, such as the rat or pig, since the mouse genome is well-characterized and there is much greater availability of both genetically-modified animals and research reagents. Liver transplant experiments using various transgenic or gene knockout mice has provided valuable mechanistic insights into the immuno- and pathobiology of the liver and the regulation of graft rejection and tolerance over the past 25 years. The molecular pathways identified in regulation of tissue injury and promotion of liver transplant tolerance provide new potential targets for therapeutic intervention to control adverse inflammatory responses/ immune-mediated events in the hepatic environment and systemically. Conclusion: Orthotopic liver transplantation in the mouse is a valuable model for gaining improved insights into liver biology, immunopathology and allograft tolerance that may result in therapeutic innovation in liver and other diseases. PMID:26709949

Innate-like control of human iNKT cell autoreactivity via the hypervariable CDR3beta loop.

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Gediminas Matulis

2010-06-01

Full Text Available Invariant Natural Killer T cells (iNKT are a versatile lymphocyte subset with important roles in both host defense and immunological tolerance. They express a highly conserved TCR which mediates recognition of the non-polymorphic, lipid-binding molecule CD1d. The structure of human iNKT TCRs is unique in that only one of the six complementarity determining region (CDR loops, CDR3beta, is hypervariable. The role of this loop for iNKT biology has been controversial, and it is unresolved whether it contributes to iNKT TCR:CD1d binding or antigen selectivity. On the one hand, the CDR3beta loop is dispensable for iNKT TCR binding to CD1d molecules presenting the xenobiotic alpha-galactosylceramide ligand KRN7000, which elicits a strong functional response from mouse and human iNKT cells. However, a role for CDR3beta in the recognition of CD1d molecules presenting less potent ligands, such as self-lipids, is suggested by the clonal distribution of iNKT autoreactivity. We demonstrate that the human iNKT repertoire comprises subsets of greatly differing TCR affinity to CD1d, and that these differences relate to their autoreactive functions. These functionally different iNKT subsets segregate in their ability to bind CD1d-tetramers loaded with the partial agonist alpha-linked glycolipid antigen OCH and structurally different endogenous beta-glycosylceramides. Using surface plasmon resonance with recombinant iNKT TCRs and different ligand-CD1d complexes, we demonstrate that the CDR3beta sequence strongly impacts on the iNKT TCR affinity to CD1d, independent of the loaded CD1d ligand. Collectively our data reveal a crucial role for CDR3beta for the function of human iNKT cells by tuning the overall affinity of the iNKT TCR to CD1d. This mechanism is relatively independent of the bound CD1d ligand and thus forms the basis of an inherent, CDR3beta dependent functional hierarchy of human iNKT cells.

CD4(+) type II NKT cells mediate ICOS and programmed death-1-dependent regulation of type 1 diabetes.

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Kadri, Nadir; Korpos, Eva; Gupta, Shashank; Briet, Claire; Löfbom, Linda; Yagita, Hideo; Lehuen, Agnes; Boitard, Christian; Holmberg, Dan; Sorokin, Lydia; Cardell, Susanna L

2012-04-01

Type 1 diabetes (T1D) is a chronic autoimmune disease that results from T cell-mediated destruction of pancreatic β cells. CD1d-restricted NKT lymphocytes have the ability to regulate immunity, including autoimmunity. We previously demonstrated that CD1d-restricted type II NKT cells, which carry diverse TCRs, prevented T1D in the NOD mouse model for the human disease. In this study, we show that CD4(+) 24αβ type II NKT cells, but not CD4/CD8 double-negative NKT cells, were sufficient to downregulate diabetogenic CD4(+) BDC2.5 NOD T cells in adoptive transfer experiments. CD4(+) 24αβ NKT cells exhibited a memory phenotype including high ICOS expression, increased cytokine production, and limited display of NK cell markers, compared with double-negative 24αβ NKT cells. Blocking of ICOS or the programmed death-1/programmed death ligand 1 pathway was shown to abolish the regulation that occurred in the pancreas draining lymph nodes. To our knowledge, these results provide for the first time cellular and molecular information on how type II CD1d-restricted NKT cells regulate T1D.

Bimodal CD40/Fas-Dependent Crosstalk between iNKT Cells and Tumor-Associated Macrophages Impairs Prostate Cancer Progression.

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Cortesi, Filippo; Delfanti, Gloria; Grilli, Andrea; Calcinotto, Arianna; Gorini, Francesca; Pucci, Ferdinando; Lucianò, Roberta; Grioni, Matteo; Recchia, Alessandra; Benigni, Fabio; Briganti, Alberto; Salonia, Andrea; De Palma, Michele; Bicciato, Silvio; Doglioni, Claudio; Bellone, Matteo; Casorati, Giulia; Dellabona, Paolo

2018-03-13

Heterotypic cellular and molecular interactions in the tumor microenvironment (TME) control cancer progression. Here, we show that CD1d-restricted invariant natural killer (iNKT) cells control prostate cancer (PCa) progression by sculpting the TME. In a mouse PCa model, iNKT cells restrained the pro-angiogenic and immunosuppressive capabilities of tumor-infiltrating immune cells by reducing pro-angiogenic TIE2 + , M2-like macrophages (TEMs), and sustaining pro-inflammatory M1-like macrophages. iNKT cells directly contacted macrophages in the PCa stroma, and iNKT cell transfer into tumor-bearing mice abated TEMs, delaying tumor progression. iNKT cells modulated macrophages through the cooperative engagement of CD1d, Fas, and CD40, which promoted selective killing of M2-like and survival of M1-like macrophages. Human PCa aggressiveness associate with reduced intra-tumoral iNKT cells, increased TEMs, and expression of pro-angiogenic genes, underscoring the clinical significance of this crosstalk. Therefore, iNKT cells may control PCa through mechanisms involving differential macrophage modulation, which may be harnessed for therapeutically reprogramming the TME. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

From Lysosomal Storage Diseases to NKT Cell Activation and Back

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Cátia S. Pereira

2017-02-01

Full Text Available Lysosomal storage diseases (LSDs are inherited metabolic disorders characterized by the accumulation of different types of substrates in the lysosome. With a multisystemic involvement, LSDs often present a very broad clinical spectrum. In many LSDs, alterations of the immune system were described. Special emphasis was given to Natural Killer T (NKT cells, a population of lipid-specific T cells that is activated by lipid antigens bound to CD1d (cluster of differentiation 1 d molecules at the surface of antigen-presenting cells. These cells have important functions in cancer, infection, and autoimmunity and were altered in a variety of LSDs’ mouse models. In some cases, the observed decrease was attributed to defects in either lipid antigen availability, trafficking, processing, or loading in CD1d. Here, we review the current knowledge about NKT cells in the context of LSDs, including the alterations detected, the proposed mechanisms to explain these defects, and the relevance of these findings for disease pathology. Furthermore, the effect of enzyme replacement therapy on NKT cells is also discussed.

The effect of intracellular trafficking of CD1d on the formation of TCR repertoire of NKT cells.

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Shin, Jung Hoon; Park, Se-Ho

2014-05-01

CD1 molecules belong to non-polymorphic MHC class I-like proteins and present lipid antigens to T cells. Five different CD1 genes (CD1a-e) have been identified and classified into two groups. Group 1 include CD1a-c and present pathogenic lipid antigens to αβ T cells reminiscence of peptide antigen presentation by MHC-I molecules. CD1d is the only member of Group 2 and presents foreign and self lipid antigens to a specialized subset of αβ T cells, NKT cells. NKT cells are involved in diverse immune responses through prompt and massive production of cytokines. CD1d-dependent NKT cells are categorized upon the usage of their T cell receptors. A major subtype of NKT cells (type I) is invariant NKT cells which utilize invariant Vα14-Jα18 TCR alpha chain in mouse. The remaining NKT cells (type II) utilize diverse TCR alpha chains. Engineered CD1d molecules with modified intracellular trafficking produce either type I or type II NKT cell-defects suggesting the lipid antigens for each subtypes of NKT cells are processed/generated in different intracellular compartments. Since the usage of TCR by a T cell is the result of antigen-driven selection, the intracellular metabolic pathways of lipid antigen are a key in forming the functional NKT cell repertoire.

Human CD1d-Restricted Natural Killer T (NKT) Cell Cytotoxicity Against Myeloid Cells

National Research Council Canada - National Science Library

Chen, Xiuxu; Gumperz, Jenny E

2006-01-01

CD1d-restricted natural killer T cells (NKT cells) are a unique subpopulation of T lymphocytes that have been shown to be able to promote potent anti-tumor responses in a number of different murine (mouse...

Type II NKT-TFH cells against Gaucher lipids regulate B-cell immunity and inflammation.

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Nair, Shiny; Boddupalli, Chandra Sekhar; Verma, Rakesh; Liu, Jun; Yang, Ruhua; Pastores, Gregory M; Mistry, Pramod K; Dhodapkar, Madhav V

2015-02-19

Chronic inflammation including B-cell activation is commonly observed in both inherited (Gaucher disease [GD]) and acquired disorders of lipid metabolism. However, the cellular mechanisms underlying B-cell activation in these settings remain to be elucidated. Here, we report that β-glucosylceramide 22:0 (βGL1-22) and glucosylsphingosine (LGL1), 2 major sphingolipids accumulated in GD, can be recognized by a distinct subset of CD1d-restricted human and murine type II natural killer T (NKT) cells. Human βGL1-22- and LGL1-reactive CD1d tetramer-positive T cells have a distinct T-cell receptor usage and genomic and cytokine profiles compared with the classical type I NKT cells. In contrast to type I NKT cells, βGL1-22- and LGL1-specific NKT cells constitutively express T-follicular helper (TFH) phenotype. Injection of these lipids leads to an increase in respective lipid-specific type II NKT cells in vivo and downstream induction of germinal center B cells, hypergammaglobulinemia, and production of antilipid antibodies. Human βGL1-22- and LGL1-specific NKT cells can provide efficient cognate help to B cells in vitro. Frequency of LGL1-specific T cells in GD mouse models and patients correlates with disease activity and therapeutic response. Our studies identify a novel type II NKT-mediated pathway for glucosphingolipid-mediated dysregulation of humoral immunity and increased risk of B-cell malignancy observed in metabolic lipid disorders. © 2015 by The American Society of Hematology.

[Sulfatide-loaded CD1d tetramer to detect typeII NKT cells in mice].

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Zhang, Gu-qin; Nie, Han-xiang; Yang, Jiong; Yu, Hong-ying

2012-07-01

To create a method of detecting typeII natural killer T (NKT) cells of mice. Biotinylated mouse CD1d monomers were mixed with sulfatide at a molar ratio of 1:3 (protein:lipid) and incubated at room temperature overnight, and then 80 μg of streptavidin-PE was added into 200 μg of the CD1d-sulfatide mixture and incubated at room temperature for 4 h to get sulfatide/CD1d tetramer. Flow cytometry was used to detect the percentage of typeII NKT cells in mononuclear cells (MNCs) of lung and spleen of normal mice, as well as the percentage of typeII NKT cells in spleen MNCs of mice after stimulated with sulfatide. In normal mice, the percentage of typeII NKT cells accounted for (0.875±0.096)% and (1.175±0.263)% in MNCs of spleen and lung; the percentage in spleen MNCs after activated with sulfatide was (2.75±0.603)%, which significantly increased as compared with that in normal mice (PNKT cells in mice.

Roquin Paralogs Differentially Regulate Functional NKT Cell Subsets.

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Drees, Christoph; Vahl, J Christoph; Bortoluzzi, Sabrina; Heger, Klaus D; Fischer, Julius C; Wunderlich, F Thomas; Peschel, Christian; Schmidt-Supprian, Marc

2017-04-01

NKT cells represent a small subset of glycolipid-recognizing T cells that are heavily implicated in human allergic, autoimmune, and malignant diseases. In the thymus, precursor cells recognize self-glycolipids by virtue of their semi-invariant TCR, which triggers NKT cell lineage commitment and maturation. During their development, NKT cells are polarized into the NKT1, NKT2, and NKT17 subsets, defined through their cytokine-secretion patterns and the expression of key transcription factors. However, we have largely ignored how the differentiation into the NKT cell subsets is regulated. In this article, we describe the mRNA-binding Roquin-1 and -2 proteins as central regulators of murine NKT cell fate decisions. In the thymus, T cell-specific ablation of the Roquin paralogs leads to a dramatic expansion of NKT17 cells, whereas peripheral mature NKT cells are essentially absent. Roquin-1/2-deficient NKT17 cells show exaggerated lineage-specific expression of nearly all NKT17-defining proteins tested. We show through mixed bone marrow chimera experiments that NKT17 polarization is mediated through cell-intrinsic mechanisms early during NKT cell development. In contrast, the loss of peripheral NKT cells is due to cell-extrinsic factors. Surprisingly, Roquin paralog-deficient NKT cells are, in striking contrast to conventional T cells, compromised in their ability to secrete cytokines. Altogether, we show that Roquin paralogs regulate the development and function of NKT cell subsets in the thymus and periphery. Copyright © 2017 by The American Association of Immunologists, Inc.

The Adaptor Protein SAP Regulates Type II NKT Cell Development, Cytokine Production and Cytotoxicity Against Lymphoma1

Science.gov (United States)

Weng, Xiufang; Liao, Chia-Min; Bagchi, Sreya; Cardell, Susanna L.; Stein, Paul L.; Wang, Chyung-Ru

2014-01-01

CD1d-restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule-associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT cell TCR transgenic mouse model (24αβTg), we demonstrated that CD1d-expressing hematopoietic cells but not thymic epithelial cells meditate efficient selection of type II NKT cells. Further, we showed that SAP regulates type II NKT cell development by controlling Egr2 and PLZF expression. SAP-deficient 24αβ transgenic T cells (24αβ T cells) exhibited an immature phenotype with reduced Th2 cytokine-producing capacity and diminished cytotoxicity to CD1d-expressing lymphoma cells. The impaired IL-4 production by SAP-deficient 24αβ T cells was associated with reduced IRF4 and GATA-3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X-linked lymphoproliferative disease caused by mutations in SAP. PMID:25236978

The adaptor protein SAP regulates type II NKT-cell development, cytokine production, and cytotoxicity against lymphoma.

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Weng, Xiufang; Liao, Chia-Min; Bagchi, Sreya; Cardell, Susanna L; Stein, Paul L; Wang, Chyung-Ru

2014-12-01

CD1d-restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT-cell TCR transgenic mouse model, we demonstrated that CD1d-expressing hematopoietic cells, but not thymic epithelial cells, meditate efficient selection of type II NKT cells. Furthermore, we showed that SAP regulates type II NKT-cell development by controlling early growth response 2 protein and promyelocytic leukemia zinc finger expression. SAP-deficient 24αβ transgenic T cells (24αβ T cells) exhibited an immature phenotype with reduced Th2 cytokine-producing capacity and diminished cytotoxicity to CD1d-expressing lymphoma cells. The impaired IL-4 production by SAP-deficient 24αβ T cells was associated with reduced IFN regulatory factor 4 and GATA-3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X-linked lymphoproliferative disease caused by mutations in SAP. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interferon-Mediated Innate Immune Responses against Malaria Parasite Liver Stages

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Jessica L. Miller

2014-04-01

Full Text Available Mosquito-transmitted malaria parasites infect hepatocytes and asymptomatically replicate as liver stages. Using RNA sequencing, we show that a rodent malaria liver-stage infection stimulates a robust innate immune response including type I interferon (IFN and IFNγ pathways. Liver-stage infection is suppressed by these infection-engendered innate responses. This suppression was abrogated in mice deficient in IFNγ, the type I IFN α/β receptor (IFNAR, and interferon regulatory factor 3. Natural killer and CD49b+CD3+ natural killer T (NKT cells increased in the liver after a primary infection, and CD1d-restricted NKT cells, which secrete IFNγ, were critical in reducing liver-stage burden of a secondary infection. Lack of IFNAR signaling abrogated the increase in NKT cell numbers in the liver, showing a link between type I IFN signaling, cell recruitment, and subsequent parasite elimination. Our findings demonstrate innate immune sensing of malaria parasite liver-stage infection and that the ensuing innate responses can eliminate the parasite.

New ways to turn on NKT cells.

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Godfrey, Dale Ian; Rossjohn, Jamie

2011-06-06

Natural killer T (NKT) cells are CD1d-restricted, lipid antigen-reactive T cells with powerful immunoregulatory potential. The prototypic antigen for NKT cells is a marine sponge-derived glycolipid, α-galactosylceramide (α-GalCer), but this is not normally encountered in the mammalian environment. Thus, there is great interest in the identification of more physiological stimuli for NKT cells, and numerous studies have shown that NKT cells are capable of responding to a range of microbial lipid-based antigens. Two new studies expand our understanding of environmental NKT cell stimuli, with one showing that CD1d-restricted NKT cell antigens are present within common house dust extract (HDE), whereas the other shows that NKT cells can respond to innate stimuli irrespective of the presence of foreign microbial antigens. Collectively, these two investigations indicate that NKT cells are far more likely to encounter foreign antigens, or innate activating signals, than previously recognized, suggesting a more central role for these cells in the immune system.

NKT Phototonics A/S

DEFF Research Database (Denmark)

Pedersen, Torben; Kurdahl, Githa

2016-01-01

To improve its profitability, NKT Photonics A/S (NKT), a small Danish company operating in the global photonics industry, was getting ready to undertake the commercialization process of its highly advanced optical fibre technology. NKT's chief executive officer (CEO) was considering two options...... of culture. It might also result in the loss of some top engineering and scientific minds and perhaps even the company's reputation. The CEO wondered if there a way to effectively introduce a business mindset to the organization while still preserving its innovation-based DNA....

[NKT cells and graft-versus-host disease-review].

Science.gov (United States)

Zhao, Lei; Hao, Sha; Yuan, Wei-Ping; Cheng, Tao

2013-10-01

NKT cells (nature killer T cells), as a regulatory cellular compartment in the immune system, express cell surface markers of T cells and NK cells. It secretes a variety of cytokines that stimulate specific antigens. Through regulating the balance of Th1/Th2, the NKT cells play an important role in prevention and treatment of graft-versus-host disease (GVHD). Its antitumor and anti-infectious effects serve as a basis of its application in allogeneic hematopoietic stem cell transplantation. A better understanding of the biological and immunological features of NKT cell, as well as its specific immune regulatory mechanisms, will further justify the rationales of using NKT cells in the management of GVHD for patients. In this review, the biologic properties, classification, differentiation and development, immune activation of NKT cells as well as the NKT cells and GVHD including the related mechanisms of prevention and treatment of GVHD with NKT cells, NKT cells and tumors, NKT cells and infection, and NKT cells and clinical GVHD are summarized.

Activation of farnesoid X receptor induces RECK expression in mouse liver

International Nuclear Information System (INIS)

Peng, Xiaomin; Wu, Weibin; Zhu, Bo; Sun, Zhichao; Ji, Lingling; Ruan, Yuanyuan; Zhou, Meiling; Zhou, Lei; Gu, Jianxin

2014-01-01

Highlights: •RECK is a novel transcriptional target gene of FXR in mouse liver. •The FXR response element is located within the intron 1 of RECK gene. •FXR agonist reverses the down-regulation of RECK in the liver in mouse NASH model. -- Abstract: Farnesoid X receptor (FXR) belongs to the ligand-activated nuclear receptor superfamily, and functions as a transcription factor regulating the transcription of numerous genes involved in bile acid homeostasis, lipoprotein and glucose metabolism. In the present study, we identified RECK, a membrane-anchored inhibitor of matrix metalloproteinases, as a novel target gene of FXR in mouse liver. We found that FXR agonist substantially augmented hepatic RECK mRNA and protein expression in vivo and in vitro. FXR regulated the transcription of RECK through directly binding to FXR response element located within intron 1 of the mouse RECK gene. Moreover, FXR agonist reversed the down-regulation of RECK in the livers from mice fed a methionine and choline deficient diet. In summary, our data suggest that RECK is a novel transcriptional target of FXR in mouse liver, and provide clues to better understanding the function of FXR in liver

Activation of farnesoid X receptor induces RECK expression in mouse liver

Energy Technology Data Exchange (ETDEWEB)

Peng, Xiaomin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Wu, Weibin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Zhu, Bo; Sun, Zhichao; Ji, Lingling; Ruan, Yuanyuan [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Zhou, Meiling, E-mail: meilingzhou2012@gmail.com [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Zhou, Lei, E-mail: yhchloech@gmail.com [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China)

2014-01-03

Highlights: •RECK is a novel transcriptional target gene of FXR in mouse liver. •The FXR response element is located within the intron 1 of RECK gene. •FXR agonist reverses the down-regulation of RECK in the liver in mouse NASH model. -- Abstract: Farnesoid X receptor (FXR) belongs to the ligand-activated nuclear receptor superfamily, and functions as a transcription factor regulating the transcription of numerous genes involved in bile acid homeostasis, lipoprotein and glucose metabolism. In the present study, we identified RECK, a membrane-anchored inhibitor of matrix metalloproteinases, as a novel target gene of FXR in mouse liver. We found that FXR agonist substantially augmented hepatic RECK mRNA and protein expression in vivo and in vitro. FXR regulated the transcription of RECK through directly binding to FXR response element located within intron 1 of the mouse RECK gene. Moreover, FXR agonist reversed the down-regulation of RECK in the livers from mice fed a methionine and choline deficient diet. In summary, our data suggest that RECK is a novel transcriptional target of FXR in mouse liver, and provide clues to better understanding the function of FXR in liver.

Antigen-specific human NKT cells from tuberculosis patients produce IL-21 to help B cells for the production of immunoglobulins.

Science.gov (United States)

Wu, Changyou; Li, Zitao; Fu, Xiaoying; Yu, Sifei; Lao, Suihua; Yang, Binyan

2015-10-06

Natural killer T (NKT) cells from mouse and human play an important role in the immune responses against Mycobacterium tuberculosis. However, the function of CD3(+)TCRvβ11(+) NKT cells at the local site of M. tuberculosis infection remains poorly defined. In the present study, we found that after stimulation with M. tuberculosis antigens, NKT cells isolated from tuberculosis (TB) pleural fluid mononuclear cells (PFMCs) produced IL-21 and other cytokines including IFN-γ, TNF-α, IL-2 and IL-17. IL-21-expressing NKT cells in PFMCs displayed effector memory phenotype, expressing CD45RO(high)CD62L(low)CCR7(low). Moreover, NKT cells expressed high levels of CXCR5 and all of IL-21-expressing NKT cells co-expressed CXCR5. The frequency of BCL-6-expression was higher in IL-21-expressing but not in non-IL-21-expressing CD3(+)TCRvβ11(+) NKT cells. Sorted CD3(+)TCRvβ11(+) NKT cells from PFMCs produced IFN-γ and IL-21 after stimulation, which expressed CD40L. Importantly, CD3(+)TCRvβ11(+) NKT cells provided help to B cells for the production of IgG and IgA. Taken together, our data demonstrate that CD3(+)TCRvβ11(+) NKT cells from a local site of M. tuberculosis infection produce IL-21, express CXCR5 and CD40L, help B cells to secrete IgG and IgA, and may participate in local immune responses against M. tuberculosis infection.

Invariant NKT cells and CD1d(+) cells amass in human omentum and are depleted in patients with cancer and obesity.

LENUS (Irish Health Repository)

Lynch, Lydia

2012-02-01

Invariant NKT (iNKT) cells recognize lipid antigens presented by CD1d and respond rapidly by killing tumor cells and release cytokines that activate and regulate adaptive immune responses. They are essential for tumor rejection in various mouse models, but clinical trials in humans involving iNKT cells have been less successful, partly due to their rarity in humans compared with mice. Here we describe an accumulation of functional iNKT cells in human omentum, a migratory organ with healing properties. Analysis of 39 omental samples revealed that T cells are the predominant lymphoid cell type and of these, 10% expressed the invariant Valpha24Jalpha18 TCR chain, found on iNKT cells, higher than in any other human organ tested to date. About 15% of omental hematopoietic cells expressed CD1d, compared with 1% in blood (p<0.001). Enriched omental iNKT cells killed CD1d(+) targets and released IFN-gamma and IL-4 upon activation. Omental iNKT-cell frequencies were lower in patients with severe obesity (p=0.005), and with colorectal carcinoma (p=0.004) compared with lean healthy subjects. These data suggest a novel role for the omentum in immune regulation and tumor immunity and identify it as a potential source of iNKT cells for therapeutic use.

A mutation within the SH2 domain of slp-76 regulates the tissue distribution and cytokine production of iNKT cells in mice

OpenAIRE

Danzer, Claudia; Koller, Anna; Baier, Julia; Arnold, Harald; Giessler, Claudia; Opoka, Robert; Schmidt, Stephanie; Willers, Maike; Mihai, Sidonia; Parsch, Hans; Wirtz, Stefan; Daniel, Christoph; Reinhold, Annegret; Engelmann, Swen; Kliche, Stefanie

2016-01-01

TCR ligation is critical for the selection, activation, and integrin expression of T lymphocytes. Here, we explored the role of the TCR adaptor protein slp-76 on iNKT-cell biology. Compared to B6 controls, slp-76ace/ace mice carrying a missense mutation (Thr428Ile) within the SH2-domain of slp-76 showed an increase in iNKT cells in the thymus and lymph nodes, but a decrease in iNKT cells in spleens and livers, along with reduced ADAP expression and cytokine response. A comparable reduct...

Dynamics of NKT-Cell Responses to Chlamydial Infection.

Science.gov (United States)

Shekhar, Sudhanshu; Joyee, Antony George; Yang, Xi

2015-01-01

Natural killer T (NKT) cells have gained great attention owing to their critical functional roles in immunity to various pathogens. In this review, we provide an overview of the current knowledge on the role of NKT cells in host defense against and pathogenesis due to Chlamydia, which is an intracellular bacterial pathogen that poses a threat to the public health worldwide. Accumulating evidence has demonstrated that NKT cells, particularly invariant NKT (iNKT) cells, play a crucial role in host defense against chlamydial infections, especially in C. pneumoniae infection. iNKT cells can promote type-1 protective responses to C. pneumoniae by inducing enhanced production of IL-12 by dendritic cells (DCs), in particular CD8α+ DCs, which promote the differentiation of naive T cells into protective IFN-γ-producing Th1/Tc1 type CD4+/CD8+ T cells. This iNKT-cell-mediated modulation of DC function is largely dependent upon CD40-CD40L interaction, IFN-γ production, and cell-to-cell contact. In addition, iNKT cells modulate the function of natural killer cells. NKT cells may be also involved in the pathogenesis of some chlamydial diseases by inducing different patterns of cytokine production. A better understanding of NKT-cell biology will enable us to rationally design prophylactic and therapeutic tools to combat infectious diseases.

Transcriptomic profiling of trichloroethylene exposure in male mouse liver

Directory of Open Access Journals (Sweden)

Yan Jiang

2015-03-01

Full Text Available Chronic Trichloroethylene (TCE exposure could induce hepatocellular carcinoma in mice, and occupational exposure in humans was suggested to be associated with liver cancer. To understand the role of non-genotoxic mechanism(s for TCE action, we examined the gene expression and DNA methylation changes in the liver of B6C3F1 mice orally administered with TCE for 5 days. As a beginning step, we profiled gene expression alterations induced by the TCE in mouse livers. Here we describe in detail the experimental methods, quality controls, and other information associated with our data deposited into Gene Expression Omnibus (GEO under GSE58819. Our data provide useful information for gene expression responses to TCE in mouse liver.

Α-galactosylceramide analogs with weak agonist activity for human iNKT cells define new candidate anti-inflammatory agents.

Directory of Open Access Journals (Sweden)

Gabriel Bricard

2010-12-01

Full Text Available CD1d-restricted natural killer T cells with invariant T cell receptor α chains (iNKT cells are a unique lymphocyte subset that responds to recognition of specific lipid and glycolipid antigens. They are conserved between mice and humans and exert various immunoregulatory functions through their rapid secretion of a variety of cytokines and secondary activation of dendritic cells, B cells and NK cells. In the current study, we analyzed the range of functional activation states of human iNKT cells using a library of novel analogs of α-galactosylceramide (αGalCer, the prototypical iNKT cell antigen. Measurement of cytokines secreted by human iNKT cell clones over a wide range of glycolipid concentrations revealed that iNKT cell ligands could be classified into functional groups, correlating with weak versus strong agonistic activity. The findings established a hierarchy for induction of different cytokines, with thresholds for secretion being consistently lowest for IL-13, higher for interferon-γ (IFNγ, and even higher for IL-4. These findings suggested that human iNKT cells can be intrinsically polarized to selective production of IL-13 by maintaining a low level of activation using weak agonists, whereas selective polarization to IL-4 production cannot be achieved through modulating the strength of the activating ligand. In addition, using a newly designed in vitro system to assess the ability of human iNKT cells to transactivate NK cells, we found that robust secondary induction of interferon-γ secretion by NK cells was associated with strong but not weak agonist ligands of iNKT cells. These results indicate that polarization of human iNKT cell responses to Th2-like or anti-inflammatory effects may best be achieved through selective induction of IL-13 and suggest potential discrepancies with findings from mouse models that may be important in designing iNKT cell-based therapies in humans.

NKT cell depletion in humans during early HIV infection.

Science.gov (United States)

Fernandez, Caroline S; Kelleher, Anthony D; Finlayson, Robert; Godfrey, Dale I; Kent, Stephen J

2014-08-01

Natural killer T (NKT) cells bridge across innate and adaptive immune responses and have an important role in chronic viral infections such as human immunodeficiency virus (HIV). NKT cells are depleted during chronic HIV infection, but the timing, drivers and implications of this NKT cell depletion are poorly understood. We studied human peripheral blood NKT cell levels, phenotype and function in 31 HIV-infected subjects not on antiretroviral treatment from a mean of 4 months to 2 years after HIV infection. We found that peripheral CD4(+) NKT cells were substantially depleted and dysfunctional by 4 months after HIV infection. The depletion of CD4(+) NKT cells was more marked than the depletion of total CD4(+) T cells. Further, the early depletion of NKT cells correlated with CD4(+) T-cell decline, but not HIV viral levels. Levels of activated CD4(+) T cells correlated with the loss of NKT cells. Our studies suggest that the early loss of NKT cells is associated with subsequent immune destruction during HIV infection.

CD1d-unrestricted NKT cells are endowed with a hybrid function far superior than that of iNKT cells.

Science.gov (United States)

Farr, Alexander R; Wu, Weisheng; Choi, Bongkum; Cavalcoli, James D; Laouar, Yasmina

2014-09-02

Invariant natural killer T (iNKT) cells to date represent the best example of cells known to have a hybrid function, representing both innate and adaptive immunity. Shared phenotypic similarities with NK cells together with a rapid response to a cytokine stimulus and a productive TCR engagement are the features that underline the hybrid nature of iNKT cells. Using these criteria, we provide molecular and functional evidence demonstrating that CD1d-independent (CD1d(ind)) NKT cells, a population of CD1d-unrestricted NKT cells, are endowed with a hybrid function far superior to that of iNKT cells: (i) an extensive shared program with NK cells, (ii) a closer Euclidian distance with NK cells, and (iii) the ability to respond to innate stimuli (Poly:IC) with cytotoxic potential in the same manner as NK cells identify a hybrid feature in CD1d(ind)NKT cells that truly fulfills the dual function of an NK and a T cell. Our finding that CD1d(ind)NKT cells are programmed to act like NK cells in response to innate signals while being capable of adaptive responses is unprecedented, and thus might reemphasize CD1d-unrestricted NKT cells as a subset of lymphocytes that could affect biological processes of antimicrobial and tumor immunity in a unique way.

Macrophage migration inhibitory factor triggers chemotaxis of CD74+CXCR2+ NKT cells in chemically induced IFN-γ-mediated skin inflammation.

Science.gov (United States)

Hsieh, Chia-Yuan; Chen, Chia-Ling; Lin, Yee-Shin; Yeh, Trai-Ming; Tsai, Tsung-Ting; Hong, Ming-Yuan; Lin, Chiou-Feng

2014-10-01

IFN-γ mediates chemically induced skin inflammation; however, the mechanism by which IFN-γ-producing cells are recruited to the sites of inflammation remains undefined. Secretion of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, from damaged cells may promote immune cell recruitment. We hypothesized that MIF triggers an initial step in the chemotaxis of IFN-γ-producing cells in chemically induced skin inflammation. Using acute and chronic models of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mouse ears, MIF expression was examined, and its role in this process was investigated pharmacologically. The cell populations targeted by MIF, their receptor expression patterns, and the effects of MIF on cell migration were examined. TPA directly caused cytotoxicity accompanied by MIF release in mouse ear epidermal keratinocytes, as well as in human keratinocytic HaCaT cells. Treatment with the MIF antagonist (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester considerably attenuated TPA-induced ear swelling, leukocyte infiltration, epidermal cell proliferation, and dermal angiogenesis. Inhibition of MIF greatly diminished the dermal infiltration of IFN-γ(+) NKT cells, whereas the addition of exogenous TPA and MIF to NKT cells promoted their IFN-γ production and migration, respectively. MIF specifically triggered the chemotaxis of NKT cells via CD74 and CXCR2, and the resulting depletion of NKT cells abolished TPA-induced skin inflammation. In TPA-induced skin inflammation, MIF is released from damaged keratinocytes and then triggers the chemotaxis of CD74(+)CXCR2(+) NKT cells for IFN-γ production. Copyright © 2014 by The American Association of Immunologists, Inc.

[Change of the Vα24 NKT cells in peripheral blood of the patients with advanced schistosomiasis and its relation to the degree of hepatic fibrosis].

Science.gov (United States)

Sun, Ting; Li, Gang; Chen, Mao-jian; Nie, Hao; Liao, Guo-xiang; Gong, Quan

2014-10-01

To investigate the change of Vα24 NKT cells number in peripheral blood and its correlation with the degree of hepatic fibrosis in patients with advanced schistosomiasis. Thirty-two advanced schistosomiasis patients and 23 healthy persons were included in the study. The percentage of peripheral blood Vα24 NKT cells was determined by flow cytometry. The relevant indicators of liver function were detected by enzyme cycling method. Type-B ultrasound was used to examine the degree of hepatic fibrosis. Flow cytometry showed that the percentage of Vα24 NKT cells in advanced schistosomiasis patients [(0.23±0.09)%] was significantly lower than that of healthy persons [(1.44±0.62)%] (PNKT cells was positively correlated with y-GT (r=0.365, P0.05). The percentage of Vα24 NKT cells in patients with grades I (5 cases), II (11 cases), and III (16 cases) fibrosis was (0.37±0.02)%, (0.28±0.04)%, (0.15±0.03)%, respectively (PNKT cells showed a significant negative correlation with the degree of liver fibrosis (r=-0.91, PNKT cells in peripheral blood decreases with the aggravation of hepatic fibrosis in patients with advanced schistosomiasis.

Activation of glioma cells generates immune tolerant NKT cells.

Science.gov (United States)

Tang, Bo; Wu, Wei; Wei, Xiaowei; Li, Yang; Ren, Gang; Fan, Wenhai

2014-12-12

Therapeutic outcomes of glioma are currently not encouraging. Tumor tolerance plays an important role in the pathogenesis of glioma. It is reported that micro RNAs (miR) are associated with tumor development. This study aims to investigate the role of miR-92a in the development of tolerant natural killer T (NKT) cells. In this study, U87 cells (a human glioma cell line) and primary glioma cells were prepared. The assessment of miR-92a was performed by real time RT-PCR. The expression of interleukin (IL)-10 and IL-6 in NKT cells was evaluated by flow cytometry. Results showed that abundant IL-6(+) IL-10(+) NKT cells were detected in glioma tissue. Cultures of glioma cells and NKT cells induced the expression of IL-6 and IL-10 in NKT cells. Glioma cells expressed miR-92a; the latter played a critical role in the induction of IL-6 and IL-10 expression in NKT cells. The expression of the antitumor molecules, including perforin, Fas ligand, and interferon-γ, was significantly attenuated compared with control NKT cells. The IL-6(+) IL-10(+) NKT cells showed less capability in the induction of apoptosis in glioma cells, but showed the immune suppressor functions on CD8(+) T cell activities. We conclude that glioma-derived miR-92a induces IL-6(+) IL-10(+) NKT cells; this fraction of NKT cells can suppress cytotoxic CD8(+) T cells. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Isolation of Kupffer Cells and Hepatocytes from a Single Mouse Liver

DEFF Research Database (Denmark)

Aparicio-Vergara, Marcela; Tencerova, Michaela; Morgantini, Cecilia

2017-01-01

Liver perfusion is a common technique used to isolate parenchymal and non-parenchymal liver cells for in vitro experiments. This method allows hepatic cells to be separated based on their size and weight, by centrifugation using a density gradient. To date, other methods allow the isolation of only...... one viable hepatic cellular fraction from a single mouse; either parenchymal (hepatocytes) or non-parenchymal cells (i.e., Kupffer cells or hepatic stellate cells). Here, we describe a method to isolate both hepatocytes and Kupffer cells from a single mouse liver, thereby providing the unique...... advantage of studying different liver cell types that have been isolated from the same organism....

Radioprotection by dipyridamole in the aging mouse. Effects on lipid peroxidation in mouse liver, spleen and brain after whole-body X-ray irradiation

International Nuclear Information System (INIS)

Seino, Noritaka

1995-01-01

To investigate the radioprotective effect of dipyridamole in the aging mouse, the lipid peroxide content in aging mouse liver, spleen and brain irradiated by X-ray were measured both before and after injection of dipyridamole. The lipid peroxide content increased with aging from 2 months old to 16 months old in the mouse liver, spleen and brain. The content of lipid peroxide in the liver and spleen of the aging mouse was significantly increased in 7 days after whole-body irradiation with 8 Gy, but was unchanged in the brain. Dipyridamole, given before irradiation, significantly inhibited the increase of lipid peroxide after irradiation. These results suggest that dipyridamole may have radioprotective effects on aging mouse liver and spleen as well as on young mouse, and that inhibition of lipid peroxidation is a possible factor in the radioprotective effect of dipyridamole. (author)

Tissue specific distribution of iNKT cells impacts their cytokine response

OpenAIRE

Lee, You Jeong; Wang, Haiguang; Starrett, Gabriel J.; Phuong, Vanessa; Jameson, Stephen C.; Hogquist, Kristin A.

2015-01-01

Three subsets of invariant natural killer T (iNKT) cells have been identified, NKT1, NKT2 and NKT17, which produce distinct cytokines when stimulated, but little is known about their localization. Here, we have defined the anatomic localization and systemic distribution of these subsets and measured their cytokine production. Thymic NKT2 cells that produced interleukin-4 (IL-4) at steady state were located in the medulla and conditioned medullary thymocytes. NKT2 cells were abundant in the me...

NKT cells in cardiovascular diseases.

Science.gov (United States)

van Puijvelde, Gijs H M; Kuiper, Johan

2017-12-05

Despite life-style advice and the prescription of cholesterol-lowering and anti-thrombotic drugs, cardiovascular diseases are still the leading cause of death worldwide. Therefore, there is an urgent need for new therapeutic strategies focussing on atherosclerosis, the major underlying pathology of cardiovascular diseases characterized by an accumulation of lipids in an inflamed arterial/vessel wall. CD1d-restricted lipid-sensing natural killer T (NKT) cells, bridging the innate and adaptive immunity, and CD1d-expressing antigen-presenting cells are detected in atherosclerotic lesions of mice and humans. In this review we will summarize studies that point to a critical role for NKT cells in the pathogenesis of atherosclerosis and other cardiovascular diseases by the secretion of pro-atherogenic cytokines and cytotoxins. These pro-atherogenic NKT cells are potential targets for new therapeutic strategies in the prevention and treatment of cardiovascular diseases. Additionally, proteins transferring lipids during atherosclerosis, which are also important in the loading of lipids onto CD1d and possible endogenous ligands responsible for the activation of NKT cells during atherosclerosis will be discussed. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Differential pulmonic NK and NKT cell responses in Schistosoma japonicum-infected mice.

Science.gov (United States)

Cha, Hefei; Qin, Wenjuan; Yang, Quan; Xie, Hongyan; Qu, Jiale; Wang, Mei; Chen, Daixiong; Wang, Fang; Dong, Nuo; Chen, Longhua; Huang, Jun

2017-02-01

Natural killer cells (NK cells) and natural killer T cells (NKT cells) play a role in anti-infection, anti-tumor, transplantation immunity, and autoimmune regulation. However, the role of NK and NKT cells during Schistosoma japonicum (S. japonicum) infection has not been widely reported, especially regarding lung infections. The aim of this study was to research the NK and NKT cell response to S. japonicum infection in the lungs of mice. Using immunofluorescent histological analysis, NK and NKT cells were found near pulmonary granulomas. Moreover, flow cytometry revealed that the percentage and number of pulmonic NK cells in S. japonicum-infected mice were significantly increased (P cell number of NKT cells were decreased compared to those of normal mice (P NKT cells was increased after infection (P NKT cells (P cells (P NKT cells significantly increased (P NKT cells (P NKT cell activation during S. japonicum infection.

Co-receptor choice by V alpha14i NKT cells is driven by Th-POK expression rather than avoidance of CD8-mediated negative selection.

Science.gov (United States)

Engel, Isaac; Hammond, Kirsten; Sullivan, Barbara A; He, Xi; Taniuchi, Ichiro; Kappes, Dietmar; Kronenberg, Mitchell

2010-05-10

Mouse natural killer T (NKT) cells with an invariant V alpha14-J alpha18 rearrangement (V alpha14 invariant [V alpha14i] NKT cells) are either CD4(+)CD8(-) or CD4(-)CD8(-). Because transgenic mice with forced CD8 expression in all T cells exhibited a profound NKT cell deficit, the absence of CD8 has been attributed to negative selection. We now present evidence that CD8 does not serve as a coreceptor for CD1d recognition and that the defect in development in CD8 transgene homozygous mice is the result of a reduction in secondary T cell receptor alpha rearrangements. Thymocytes from mice hemizygous for the CD8 transgene have a less severe rearrangement defect and have functional CD8(+) V alpha14i NKT cells. Furthermore, we demonstrate that the transcription factor Th, Poxviruses and Zinc finger, and Krüppel family (Th-POK) is expressed by V alpha14i NKT cells throughout their differentiation and is necessary both to silence CD8 expression and for the functional maturity of V alpha14i NKT cells. We therefore suggest that Th-POK expression is required for the normal development of V alpha14i NKT cells and that the absence of CD8 expression by these cells is a by-product of such expression, as opposed to the result of negative selection of CD8-expressing V alpha14i NKT cells.

NKT sublineage specification and survival requires the ubiquitin-modifying enzyme TNFAIP3/A20.

Science.gov (United States)

Drennan, Michael B; Govindarajan, Srinath; Verheugen, Eveline; Coquet, Jonathan M; Staal, Jens; McGuire, Conor; Taghon, Tom; Leclercq, Georges; Beyaert, Rudi; van Loo, Geert; Lambrecht, Bart N; Elewaut, Dirk

2016-09-19

Natural killer T (NKT) cells are innate lymphocytes that differentiate into NKT1, NKT2, and NKT17 sublineages during development. However, the signaling events that control NKT sublineage specification and differentiation remain poorly understood. Here, we demonstrate that the ubiquitin-modifying enzyme TNFAIP3/A20, an upstream regulator of T cell receptor (TCR) signaling in T cells, is an essential cell-intrinsic regulator of NKT differentiation. A20 is differentially expressed during NKT cell development, regulates NKT cell maturation, and specifically controls the differentiation and survival of NKT1 and NKT2, but not NKT17, sublineages. Remaining A20-deficient NKT1 and NKT2 thymocytes are hyperactivated in vivo and secrete elevated levels of Th1 and Th2 cytokines after TCR ligation in vitro. Defective NKT development was restored by compound deficiency of MALT1, a key downstream component of TCR signaling in T cells. These findings therefore show that negative regulation of TCR signaling during NKT development controls the differentiation and survival of NKT1 and NKT2 cells. © 2016 Drennan et al.

Haemozoin Detection in Mouse Liver Histology Using Simple Polarized Light Microscope

OpenAIRE

DWI RAMADHANI; SITI NURHAYATI; TUR RAHARDJO

2014-01-01

The presence of malarial pigment (haemozoin) due to Plasmodium infection is a common histopathological effect in mouse liver. Previous research showed that by using a polarized light microscope, researchers were better able to detect haemozoin in mouse liver histology section. Thus, the aim of this research was to compare the haemozoin area observed by a conventional vs. simple polarized light microscope by using image processing analysis. A total of 40 images produced from both conventional ...

Genome-wide identification of estrogen receptor alpha-binding sites in mouse liver

DEFF Research Database (Denmark)

Gao, Hui; Fält, Susann; Sandelin, Albin

2007-01-01

We report the genome-wide identification of estrogen receptor alpha (ERalpha)-binding regions in mouse liver using a combination of chromatin immunoprecipitation and tiled microarrays that cover all nonrepetitive sequences in the mouse genome. This analysis identified 5568 ERalpha-binding regions...... genes. The majority of ERalpha-binding regions lie in regions that are evolutionarily conserved between human and mouse. Motif-finding algorithms identified the estrogen response element, and variants thereof, together with binding sites for activator protein 1, basic-helix-loop-helix proteins, ETS...... signaling in mouse liver, by characterizing the first step in this signaling cascade, the binding of ERalpha to DNA in intact chromatin....

NKT Cell Networks in the Regulation of Tumor Immunity

Science.gov (United States)

Robertson, Faith C.; Berzofsky, Jay A.; Terabe, Masaki

2014-01-01

CD1d-restricted natural killer T (NKT) cells lie at the interface between the innate and adaptive immune systems and are important mediators of immune responses and tumor immunosurveillance. These NKT cells uniquely recognize lipid antigens, and their rapid yet specific reactions influence both innate and adaptive immunity. In tumor immunity, two NKT subsets (type I and type II) have contrasting roles in which they not only cross-regulate one another, but also impact innate immune cell populations, including natural killer, dendritic, and myeloid lineage cells, as well as adaptive populations, especially CD8+ and CD4+ T cells. The extent to which NKT cells promote or suppress surrounding cells affects the host’s ability to prevent neoplasia and is consequently of great interest for therapeutic development. Data have shown the potential for therapeutic use of NKT cell agonists and synergy with immune response modifiers in both pre-clinical studies and preliminary clinical studies. However, there is room to improve treatment efficacy by further elucidating the biological mechanisms underlying NKT cell networks. Here, we discuss the progress made in understanding NKT cell networks, their consequent role in the regulation of tumor immunity, and the potential to exploit that knowledge in a clinical setting. PMID:25389427

NKT cell networks in the regulation of tumor immunity.

Science.gov (United States)

Robertson, Faith C; Berzofsky, Jay A; Terabe, Masaki

2014-01-01

CD1d-restricted natural killer T (NKT) cells lie at the interface between the innate and adaptive immune systems and are important mediators of immune responses and tumor immunosurveillance. These NKT cells uniquely recognize lipid antigens, and their rapid yet specific reactions influence both innate and adaptive immunity. In tumor immunity, two NKT subsets (type I and type II) have contrasting roles in which they not only cross-regulate one another, but also impact innate immune cell populations, including natural killer, dendritic, and myeloid lineage cells, as well as adaptive populations, especially CD8(+) and CD4(+) T cells. The extent to which NKT cells promote or suppress surrounding cells affects the host's ability to prevent neoplasia and is consequently of great interest for therapeutic development. Data have shown the potential for therapeutic use of NKT cell agonists and synergy with immune response modifiers in both pre-clinical studies and preliminary clinical studies. However, there is room to improve treatment efficacy by further elucidating the biological mechanisms underlying NKT cell networks. Here, we discuss the progress made in understanding NKT cell networks, their consequent role in the regulation of tumor immunity, and the potential to exploit that knowledge in a clinical setting.

NKT cell networks in the regulation of tumor immunity

Directory of Open Access Journals (Sweden)

Faith C Robertson

2014-10-01

Full Text Available CD1d-restricted natural killer T (NKT cells lie at the interface between the innate and adaptive immune systems and are important mediators of immune responses and tumor immunosurveillance. These NKT cells uniquely recognize lipid antigens, and their rapid yet specific reactions influence both innate and adaptive immunity. In tumor immunity, two NKT subsets (type I and type II have contrasting roles in which they not only cross-regulate one another, but also impact innate immune cell populations, including natural killer, dendritic and myeloid lineage cells, as well as adaptive populations, especially CD8+ and CD4+ T cells. The extent to which NKT cells promote or suppress surrounding cells affects the host’s ability to prevent neoplasia and is consequently of great interest for therapeutic development. Data have shown the potential for therapeutic use of NKT cell agonists and synergy with immune response modifiers in both pre-clinical studies and preliminary clinical studies. However, there is room to improve treatment efficacy by further elucidating the biological mechanisms underlying NKT cell networks. Here, we discuss the progress made in understanding NKT cell networks, their consequent role in the regulation of tumor immunity, and the potential to exploit that knowledge in a clinical setting.

Mouse models in liver cancer research: A review of current literature

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Leenders, Martijn WH; Nijkamp, Maarten W; Rinkes, Inne HM Borel

2008-01-01

Primary liver cancer remains one of the most lethal malignancies worldwide. Due to differences in prevalence of etiological factors the incidence of primary liver cancer varies among the world, with a peak in East-Asia. As this disease is still lethal in most of the cases, research has to be done to improve our understanding of the disease, offering insights for possible treatment options. For this purpose, animal models are widely used, especially mouse models. In this review, we describe the different types of mouse models used in liver cancer research, with emphasis on genetically engineered mice used in this field. We focus on hepatocellular carcinoma (HCC), as this is by far the most common type of primary liver cancer, accounting for 70%-85% of cases. PMID:19058325

Invariant NKT cells as novel targets for immunotherapy in solid tumors.

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Pilones, Karsten A; Aryankalayil, Joseph; Demaria, Sandra

2012-01-01

Natural killer T (NKT) cells are a small population of lymphocytes that possess characteristics of both innate and adaptive immune cells. They are uniquely poised to respond rapidly to infection and inflammation and produce cytokines that critically shape the ensuing adaptive cellular response. Therefore, they represent promising therapeutic targets. In cancer, NKT cells are attributed a role in immunosurveillance. NKT cells also act as potent activators of antitumor immunity when stimulated with a synthetic agonist in experimental models. However, in some settings, NKT cells seem to act as suppressors and regulators of antitumor immunity. Here we briefly review current data supporting these paradoxical roles of NKT cells and their regulation. Increased understanding of the signals that determine the function of NKT cells in cancer will be essential to improve current strategies for NKT-cell-based immunotherapeutic approaches.

Invariant NKT Cells as Novel Targets for Immunotherapy in Solid Tumors

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Karsten A. Pilones

2012-01-01

Full Text Available Natural killer T (NKT cells are a small population of lymphocytes that possess characteristics of both innate and adaptive immune cells. They are uniquely poised to respond rapidly to infection and inflammation and produce cytokines that critically shape the ensuing adaptive cellular response. Therefore, they represent promising therapeutic targets. In cancer, NKT cells are attributed a role in immunosurveillance. NKT cells also act as potent activators of antitumor immunity when stimulated with a synthetic agonist in experimental models. However, in some settings, NKT cells seem to act as suppressors and regulators of antitumor immunity. Here we briefly review current data supporting these paradoxical roles of NKT cells and their regulation. Increased understanding of the signals that determine the function of NKT cells in cancer will be essential to improve current strategies for NKT-cell-based immunotherapeutic approaches.

Diacylglycerol kinase zeta positively controls the development of iNKT-17 cells.

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Jinhong Wu

Full Text Available Invariant natural killer T (iNKT cells play important roles in bridging innate and adaptive immunity via rapidly producing a variety of cytokines. A small subset of iNKT cells produces IL-17 and is generated in the thymus during iNKT-cell ontogeny. The mechanisms that control the development of these IL-17-producing iNKT-17 cells (iNKT-17 are still not well defined. Diacylglycerol kinase ζ (DGKζ belongs to a family of enzymes that catalyze the phosphorylation and conversion of diacylglycerol to phosphatidic acid, two important second messengers involved in signaling from numerous receptors. We report here that DGKζ plays an important role in iNKT-17 development. A deficiency of DGKζ in mice causes a significant reduction of iNKT-17 cells, which is correlated with decreased RORγt and IL-23 receptor expression. Interestingly, iNKT-17 defects caused by DGKζ deficiency can be corrected in chimeric mice reconstituted with mixed wild-type and DGKζ-deficient bone marrow cells. Taken together, our data identify DGKζ as an important regulator of iNKT-17 development through iNKT-cell extrinsic mechanisms.

Targeted disruption of CD1d prevents NKT cell development in pigs.

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Yang, Guan; Artiaga, Bianca L; Hackmann, Timothy J; Samuel, Melissa S; Walters, Eric M; Salek-Ardakani, Shahram; Driver, John P

2015-06-01

Studies in mice genetically lacking natural killer T (NKT) cells show that these lymphocytes make important contributions to both innate and adaptive immune responses. However, the usefulness of murine models to study human NKT cells is limited by the many differences between mice and humans, including that their NKT cell frequencies, subsets, and distribution are dissimilar. A more suitable model may be swine that share many metabolic, physiological, and growth characteristics with humans and are also similar for NKT cells. Thus, we analyzed genetically modified pigs made deficient for CD1d that is required for the development of Type I invariant NKT (iNKT) cells that express a semi-invariant T-cell receptor (TCR) and Type II NKT cells that use variable TCRs. Peripheral blood analyzed by flow cytometry and interferon-γ enzyme-linked immuno spot assays demonstrated that CD1d-knockout pigs completely lack iNKT cells, while other leukocyte populations remain intact. CD1d and NKT cells have been shown to be involved in shaping the composition of the commensal microbiota in mice. Therefore, we also compared the fecal microbiota profile between pigs expressing and lacking NKT cells. However, no differences were found between pigs lacking or expressing CD1d. Our results are the first to show that knocking-out CD1d prevents the development of NKT cells in a non-rodent species. CD1d-deficient pigs should offer a useful model to more accurately determine the contribution of NKT cells for human immune responses. They also have potential for understanding how NKT cells impact the health of commercial swine.

iNKT cells require TSC1 for terminal maturation and effector lineage fate decisions

OpenAIRE

Wu, Jinhong; Yang, Jialong; Yang, Kai; Wang, Hongxia; Gorentla, Balachandra; Shin, Jinwook; Qiu, Yurong; Que, Loretta G.; Foster, W. Michael; Xia, Zhenwei; Chi, Hongbo; Zhong, Xiao-Ping

2014-01-01

Terminal maturation of invariant NKT (iNKT) cells from stage 2 (CD44+NK1.1–) to stage 3 (CD44+NK1.1+) is accompanied by a functional acquisition of a predominant IFN-γ–producing (iNKT-1) phenotype; however, some cells develop into IL-17–producing iNKT (iNKT-17) cells. iNKT-17 cells are rare and restricted to a CD44+NK1.1– lineage. It is unclear how iNKT terminal maturation is regulated and what factors mediate the predominance of iNKT-1 compared with iNKT-17. The tumor suppressor tuberous scl...

Harnessing Invariant NKT Cells to Improve Influenza Vaccines: A Pig Perspective

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Guan Yang

2017-12-01

Full Text Available Invariant natural killer T (iNKT cells are an “innate-like” T cell lineage that recognize glycolipid rather than peptide antigens by their semi-invariant T cell receptors. Because iNKT cells can stimulate an extensive array of immune responses, there is considerable interest in targeting these cells to enhance human vaccines against a wide range of microbial pathogens. However, long overlooked is the potential to harness iNKT cell antigens as vaccine adjuvants for domestic animal species that express the iNKT cell–CD1d system. In this review, we discuss the prospect of targeting porcine iNKT cells as a strategy to enhance the efficiency of swine influenza vaccines. In addition, we compare the phenotype and tissue distribution of porcine iNKT cells. Finally, we discuss the challenges that must be overcome before iNKT cell agonists can be contemplated for veterinary use in livestock.

T cell Ig domain and mucin domain 1 engagement on invariant NKT cells in the presence of TCR stimulation enhances IL-4 production but inhibits IFN-gamma production.

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Kim, Hye Sung; Kim, Hyun Soo; Lee, Chang Woo; Chung, Doo Hyun

2010-04-15

The T cell Ig domain and mucin domain (TIM)1 protein expressed on the surface of Th2 cells regulates the immune response by modulating cytokine production. However, the functional roles of TIM1 have not been examined in NKT cells. Therefore, we investigated the immunologic effects of TIM1 on NKT cells. We found that mouse NK1.1(+)TCR-beta(+), alpha-galactosyl ceramide/CD1d dimer(+) NKT, and NKT hybridoma (DN32.D3) cells constitutively express TIM1 and TIM4 on their surface. Engagement of TIM1 on NKT cells by any of several anti-TIM1 mAbs suppressed the production of IFN-gamma in the presence of TCR stimulation in vitro and in vivo, whereas the effects of such engagement on Th2 cytokine production by the NKT cells varied with the particular anti-TIM1 Ab clone. Moreover, in DN32.D3 TIM4-knockdown NKT hybridoma cells, TIM1 engagement by rTIM1 or TIM4 enhanced IL-4 production while inhibiting IFN-gamma production in the presence of alpha-galactosyl ceramide stimulation. TIM1 engagement increased GATA-3 expression but reduced T-bet expression in NKT cells in the presence of TCR engagement. The adoptive transfer of NKT cells preincubated with anti-TIM1 mAbs into Jalpha18(-/-) mice aggravated bleomycin-induced pulmonary fibrosis by suppressing IFN-gamma production. Taken together, these results suggest that TIM1 costimulation on NKT cells enhances the cellular production of IL-4 while inhibiting the production of IFN-gamma. Thus, as a differential regulator of the immune response, TIM1 on NKT cells may be a useful therapeutic target for immune diseases.

Critical role of NKT cells in posttransplant alloantibody production.

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Zimmerer, J M; Swamy, P; Sanghavi, P B; Wright, C L; Abdel-Rasoul, M; Elzein, S M; Brutkiewicz, R R; Bumgardner, G L

2014-11-01

We previously reported that posttransplant alloantibody production in CD8-deficient hosts is IL-4+ CD4+ T cell-dependent and IgG1 isotype-dominant. The current studies investigated the hypothesis that IL-4-producing natural killer T cells (NKT cells) contribute to maximal alloantibody production. To investigate this, alloantibody levels were examined in CD8-deficient WT, CD1d KO and Jα18 KO transplant recipients. We found that the magnitude of IgG1 alloantibody production was critically dependent on the presence of type I NKT cells, which are activated by day 1 posttransplant. Unexpectedly, type I NKT cell contribution to enhanced IgG1 alloantibody levels was interferon-γ-dependent and IL-4-independent. Cognate interactions between type I NKT and B cells alone do not stimulate alloantibody production. Instead, NKT cells appear to enhance maturation of IL-4+ CD4+ T cells. To our knowledge, this is the first report to substantiate a critical role for type I NKT cells in enhancing in vivo antibody production in response to endogenous antigenic stimuli. © Copyright 2014 The American Society of Transplantation and the American Society of Transplant Surgeons.

IL-15 regulates homeostasis and terminal maturation of NKT cells1

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Gordy, Laura E.; Bezbradica, Jelena S.; Flyak, Andrew I.; Spencer, Charles T.; Dunkle, Alexis; Sun, Jingchun; Stanic, Aleksandar K.; Boothby, Mark R.; He, You-Wen; Zhao, Zhongming; Van Kaer, Luc; Joyce, Sebastian

2011-01-01

Semi-invariant natural killer T (NKT) cells are thymus-derived innate lymphocytes that modulate microbial and tumour immunity as well as autoimmune diseases. These immunoregulatory properties of NKT cells are acquired during their development. Much has been learnt regarding the molecular and cellular cues that promote NKT cell development, yet how these cells are maintained in the thymus and the periphery and how they acquire functional competence are incompletely understood. We found that IL-15 induced several Bcl-2 family survival factors in thymic and splenic NKT cells in vitro. Yet, IL15-mediated thymic and peripheral NKT cell survival critically depended on Bcl-xL expression. Additionally, IL-15 regulated thymic developmental stage 2 (ST2) to ST3 lineage progression and terminal NKT cell differentiation. Global gene expression analyses and validation revealed that IL-15 regulated Tbx21 (T-bet) expression in thymic NKT cells. The loss of IL15 also resulted in poor expression of key effector molecules such as IFN-γ, granzyme A and C as well as several NK cell receptors in NKT cells. Taken together, our findings reveal a critical role for IL-15 in NKT cell survival, which is mediated by Bcl-xL, and effector differentiation, which is consistent with a role of T-bet in regulating terminal maturation. PMID:22084435

Quantitative changes in endogenous DNA adducts correlate with conazole mutagenicity and tumorigenicity in mouse liver.**

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We have previously shown that the conazole fungicides triadimefon and propiconazole, which are tumorigenic in mouse liver, are in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses. The nontumorigenic conazole myclo...

Quantitative changes in endogenous DNA adducts correlate with conazole mutagenicity and tumorigenicity in mouse liver.

Science.gov (United States)

We have previously shown that the conazole fungicides triadimefon and propiconazole, which are tumorigenic in mouse liver, are in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses. The nontumorigenic conazole myclo...

NKT-cell glycolipid agonist as adjuvant in synthetic vaccine.

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Liu, Zheng; Guo, Jun

2017-11-27

NKT cells are CD1d-restricted, glycolipid antigen-reactive, immunoregulatory T lymphocytes that can serve as a bridge between the innate and adaptive immunities. NKT cells have a wide range of therapeutic application in autoimmunity, transplant biology, infectious disease, cancer, and vaccinology. Rather than triggering "danger signal" and eliciting an innate immune response, αGalCer-based NKT-cell agonist act via a unique mechanism, recruiting NKT cells which play a T helper-like role even without peptide as Th epitope. Importantly, the non-polymorphism of CD1d render glycolipid a universal helper epitope, offering the potential to simplify the vaccine construct capable of eliciting consistent immune response in different individuals. This review details recent advances in the design of synthetic vaccines using NKT-cell agonist as adjuvant, highlighting the role of organic synthesis and conjugation technique to enhance the immunological actives and to simplify the vaccine constructs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Withaferin A Suppresses Liver Tumor Growth in a Nude Mouse ...

African Journals Online (AJOL)

Purpose: To investigate the effect of withaferin A on tumor growth and metastasis in liver in a nude mouse model. Methods: Withaferin A was injected through a portal vein to the orthotopic liver tumor in a nude mice model. Xenogen in vivo imaging system was used to monitor tumor growth and metastasis. The effect of ...

Differential surface phenotype and context-dependent reactivity of functionally diverse NKT cells.

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Cameron, Garth; Godfrey, Dale I

2018-03-05

Natural Killer T (NKT) cells are a functionally diverse population that recognizes lipid-based antigens in association with the antigen-presenting molecule CD1d. Here, we define a technique to separate the functionally distinct thymic NKT1, NKT2 and NKT17 cell subsets by their surface expression of CD278 (ICOS) and the activation-associated glycoform of CD43, enabling the investigation of subset-specific effector-functions. We report that all three subsets express the transcription factor GATA-3 and the potential to produce IL-4 and IL-10 following activation. This questions the notion that NKT2 cells are the predominant source of IL-4 within the NKT cell pool, and suggests that IL-10-production may be more indicative of NKT cell plasticity than the existence of a distinct regulatory lineage or subset. We also show that many NKT17 cells are CD4 + and are biased toward Vβ8.3 TCR gene usage. Lastly, we demonstrate that the toll-like receptor (TLR) ligand lipopolysaccharide (LPS) can induce a NKT17 cell-biased response, even in the absence of exogenous antigen, and that combining LPS with α-GalCer resulted in enhanced IL-17A-production, and reduced levels of the immunosuppressive cytokine IL-10. This study provides a novel means to examine the context-dependent reactivity of the functionally heterogeneous NKT cell population and provides important new insight into the functional biology of these subsets. © 2018 Australasian Society for Immunology Inc.

iNKT Cells and Their potential Lipid Ligands during Viral Infection

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Anunya eOpasawatchai

2015-07-01

Full Text Available Invariant natural killer T (iNKT cells are a unique population of lipid reactive CD1d restricted innate-like T lymphocytes. Despite being a minor population, they serve as an early source of cytokines and promote immunological crosstalk thus bridging innate and adaptive immunity. Diseases ranging from allergy, autoimmunity, and cancer as well as infectious diseases, including viral infection, have been reported to be influenced by iNKT cells. However, it remains unclear how iNKT cells are activated during viral infection, as virus derived lipid antigens have not been reported. Cytokines may activate iNKT cells during infections from influenza and murine cytomegalovirus (MCMV, although CD1d dependent activation is evident in other viral infections. Several viruses, such as dengue virus (DENV, induce CD1d upregulation which correlates with iNKT cell activation. In contrast, Herpes simplex virus type 1 (HSV-1, Human immunodeficiency virus (HIV, Epstein-Barr virus (EBV and Human papiloma virus (HPV promote CD1d downregulation as a strategy to evade iNKT cell recognition. These observations suggest the participation of a CD1d-dependent process in the activation of iNKT cells in response to viral infection. Endogenous lipid ligands, including phospholipids as well as glycosphingolipids, such as glucosylceramide have been proposed to mediate iNKT cell activation. Pro-inflammatory signals produced during viral infection may stimulate iNKT cells through enhanced CD1d dependent endogenous lipid presentation. Furthermore, viral infection may alter lipid composition and inhibit endogenous lipid degradation. Recent advances in this field are reviewed.

Liver BCATm transgenic mouse model reveals the important role of the liver in maintaining BCAA homeostasis.

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Ananieva, Elitsa A; Van Horn, Cynthia G; Jones, Meghan R; Hutson, Susan M

2017-02-01

Unlike other amino acids, the branched-chain amino acids (BCAAs) largely bypass first-pass liver degradation due to a lack of hepatocyte expression of the mitochondrial branched-chain aminotransferase (BCATm). This sets up interorgan shuttling of BCAAs and liver-skeletal muscle cooperation in BCAA catabolism. To explore whether complete liver catabolism of BCAAs may impact BCAA shuttling in peripheral tissues, the BCATm gene was stably introduced into mouse liver. Two transgenic mouse lines with low and high hepatocyte expression of the BCATm transgene (LivTg-LE and LivTg-HE) were created and used to measure liver and plasma amino acid concentrations and determine whether the first two BCAA enzymatic steps in liver, skeletal muscle, heart and kidney were impacted. Expression of the hepatic BCATm transgene lowered the concentrations of hepatic BCAAs while enhancing the concentrations of some nonessential amino acids. Extrahepatic BCAA metabolic enzymes and plasma amino acids were largely unaffected, and no growth rate or body composition differences were observed in the transgenic animals as compared to wild-type mice. Feeding the transgenic animals a high-fat diet did not reverse the effect of the BCATm transgene on the hepatic BCAA catabolism, nor did the high-fat diet cause elevation in plasma BCAAs. However, the high-fat-diet-fed BCATm transgenic animals experienced attenuation in the mammalian target of rapamycin (mTOR) pathway in the liver and had impaired blood glucose tolerance. These results suggest that complete liver BCAA metabolism influences the regulation of glucose utilization during diet-induced obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

Type II NKT Cells in Inflammation, Autoimmunity, Microbial Immunity, and Cancer.

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Marrero, Idania; Ware, Randle; Kumar, Vipin

2015-01-01

Natural killer T cells (NKT) recognize self and microbial lipid antigens presented by non-polymorphic CD1d molecules. Two major NKT cell subsets, type I and II, express different types of antigen receptors (TCR) with distinct mode of CD1d/lipid recognition. Though type II NKT cells are less frequent in mice and difficult to study, they are predominant in human. One of the major subsets of type II NKT cells reactive to the self-glycolipid sulfatide is the best characterized and has been shown to induce a dominant immune regulatory mechanism that controls inflammation in autoimmunity and in anti-cancer immunity. Recently, type II NKT cells reactive to other self-glycolipids and phospholipids have been identified suggesting both promiscuous and specific TCR recognition in microbial immunity as well. Since the CD1d pathway is highly conserved, a detailed understanding of the biology and function of type II NKT cells as well as their interplay with type I NKT cells or other innate and adaptive T cells will have major implications for potential novel interventions in inflammatory and autoimmune diseases, microbial immunity, and cancer.

IL-12 and IL-18 Induction and Subsequent NKT Activation Effects of the Japanese Botanical Medicine Juzentaihoto

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Ken Taniguchi

2008-07-01

Full Text Available In this study, we first measured some cytokine concentrations in the serum of patients treated with Juzentaihoto (JTT. Of the cytokines measured interleukin (IL -18 was the most prominently up-regulated cytokine in the serum of patients under long term JTT administration. We next evaluated the effects of JTT in mice, focusing especially on natural killer T (NKT cell induction. Mice fed JTT were compared to control group ones. After sacrifice, the liver was fixed, embedded and stained. Transmission electron microscope (TEM observations were performed. Although the mice receiving the herbal medicine had same appearance, their livers were infiltrated with massive mononuclear cells, some of which were aggregated to form clusters. Immunohistochemical staining revealed that there was abundant cytokine expression of IL-12 and IL-18 in the liver of JTT treated mice. To clarify what the key molecules that induce immunological restoration with JTT might be, we next examined in vitro lymphocyte cultures. Mononuclear cells isolated and prepared from healthy volunteers were cultured with and without JTT. Within 24 hours, JTT induced the IL-12 and IL-18 production and later (72 hours induction of interferon (IFN-gamma. Oral administration of JTT may induce the expression of IL-12 in the early stage, and IL-18 in the chronic stage, followed by NKT induction. Their activation, following immunological restoration could contribute to anti-tumor effects.

IL-12 and IL-18 induction and subsequent NKT activation effects of the Japanese botanical medicine Juzentaihoto.

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Fujiki, Kazuhiko; Nakamura, Masanori; Matsuda, Takako; Isogai, Mariko; Ikeda, Minako; Yamamoto, Yutaka; Kitamura, Mari; Sazaki, Naoko; Yakushiji, Fumiatsu; Suzuki, Shinji; Tomiyama, Junji; Uchida, Takashi; Taniguchi, Ken

2008-06-01

In this study, we first measured some cytokine concentrations in the serum of patients treated with Juzentaihoto (JTT). Of the cytokines measured interleukin (IL) -18 was the most prominently up-regulated cytokine in the serum of patients under long term JTT administration. We next evaluated the effects of JTT in mice, focusing especially on natural killer T (NKT) cell induction. Mice fed JTT were compared to control group ones. After sacrifice, the liver was fixed, embedded and stained. Transmission electron microscope (TEM) observations were performed. Although the mice receiving the herbal medicine had same appearance, their livers were infiltrated with massive mononuclear cells, some of which were aggregated to form clusters. Immunohistochemical staining revealed that there was abundant cytokine expression of IL-12 and IL-18 in the liver of JTT treated mice. To clarify what the key molecules that induce immunological restoration with JTT might be, we next examined in vitro lymphocyte cultures. Mononuclear cells isolated and prepared from healthy volunteers were cultured with and without JTT. Within 24 hours, JTT induced the IL-12 and IL-18 production and later (72 hours) induction of interferon (IFN)-gamma. Oral administration of JTT may induce the expression of IL-12 in the early stage, and IL-18 in the chronic stage, followed by NKT induction. Their activation, following immunological restoration could contribute to anti-tumor effects.

NKT sublineage specification and survival requires the ubiquitin-modifying enzyme TNF AIP3/A20

NARCIS (Netherlands)

Drennan, M.B. (Michael B.); Govindarajan, S. (Srinath); Verheugen, E. (Eveline); Coquet, J.M. (Jonathan M.); Staal, J. (Jens); McGuire, C. (Conor); T. Taghon (Tom); G. Leclercq (Georges); R. Beyaert (Rudi); G. van Loo (Geert); B.N.M. Lambrecht (Bart); Elewaut, D. (Dirk)

2016-01-01

textabstractNatural killer T (NKT) cells are innate lymphocytes that differentiate into NKT1, NKT2, and NKT17 sublineages during development. However, the signaling events that control NKT sublineage specification and differentiation remain poorly understood. Here, we demonstrate that the

Haemozoin Detection in Mouse Liver Histology Using Simple Polarized Light Microscope

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DWI RAMADHANI

2014-03-01

Full Text Available The presence of malarial pigment (haemozoin due to Plasmodium infection is a common histopathological effect in mouse liver. Previous research showed that by using a polarized light microscope, researchers were better able to detect haemozoin in mouse liver histology section. Thus, the aim of this research was to compare the haemozoin area observed by a conventional vs. simple polarized light microscope by using image processing analysis. A total of 40 images produced from both conventional light microscope and simple polarized light microscope were collected. All images were analyzed using ImageJ 1.47 software to measure the haemozoin areas. Our results showed that non birefringent haemozoin and birefringent haemozoin area was significantly different. This was because when using conventional light microscope the brown area that contained images of non birefringent haemozoin images also contained Kupffer cells which appeared as the same brown color as haemozoin. In contrast, haemozoin gave bright effect and can be easily differentiated with Kupffer cells in the birefringent haemozoin images. This study concluded that haemozoin detection in mouse liver histology using a simple polarized light microscope was more accurate compared to that of conventional light microscope.

The effect of radiotherapy on NKT cells in patients with advanced head and neck cancer.

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Kobayashi, Kouichi; Tanaka, Yuriko; Horiguchi, Shigetoshi; Yamamoto, Shouji; Toshinori, Nakayama; Sugimoto, Akira; Okamoto, Yoshitaka

2010-10-01

Cancer immunotherapy with NKT cells is a potential new treatment strategy for advanced head and neck cancer. NKT cell therapy is promising due to its unique anti-tumor activity and higher degree of safety compared to current therapies. Radiotherapy is indispensable as a standard treatment for advanced head and neck cancer. To elucidate the possibility of using NKT cells as an adjuvant immunotherapy with radiotherapy, we examined the effect of radiotherapy on NKT cells in patients with head and neck cancer. The number, IFN-gamma production and proliferation capacity of NKT cells were analyzed before and after 50 Gy radiation therapy in 12 patients with stage IV head and neck squamous cell carcinoma. The cytotoxic activity of NKT cells was examined in vitro. The number of NKT cells in the blood varied widely between patients. After radiation therapy, the population of CD3 T cells decreased significantly, while the NKT cell population remained stable. The number of NKT cells was the same after radiation therapy as before. IFN-gamma production from NKT cells collected just after radiotherapy was impaired after stimulation with exogenous ligand, but the proliferative responses of these NKT cells was enhanced in comparison to those collected before radiation therapy. Furthermore, the proliferated NKT cells displayed a significant level of anti-tumor activity. NKT cells are relatively resistant to radiation and might therefore be suitable for adjuvant immunotherapy to eradicate remnant cancer cells in patients who have undergone radiation therapy.

Alterations in cellular metabolism modulate CD1d-mediated NKT-cell responses.

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Webb, Tonya J; Carey, Gregory B; East, James E; Sun, Wenji; Bollino, Dominique R; Kimball, Amy S; Brutkiewicz, Randy R

2016-08-01

Natural killer T (NKT) cells play a critical role in the host's innate immune response. CD1d-mediated presentation of glycolipid antigens to NKT cells has been established; however, the mechanisms by which NKT cells recognize infected or cancerous cells remain unclear. 5(')-AMP activated protein kinase (AMPK) is a master regulator of lipogenic pathways. We hypothesized that activation of AMPK during infection and malignancy could alter the repertoire of antigens presented by CD1d and serve as a danger signal to NKT cells. In this study, we examined the effect of alterations in metabolism on CD1d-mediated antigen presentation to NKT cells and found that an infection with lymphocytic choriomeningitis virus rapidly increased CD1d-mediated antigen presentation. Hypoxia inducible factors (HIF) enhance T-cell effector functions during infection, therefore antigen presenting cells pretreated with pharmacological agents that inhibit glycolysis, induce HIF and activate AMPK were assessed for their ability to induce NKT-cell responses. Pretreatment with 2-deoxyglucose, cobalt chloride, AICAR and metformin significantly enhanced CD1d-mediated NKT-cell activation. In addition, NKT cells preferentially respond to malignant B cells and B-cell lymphomas express HIF-1α. These data suggest that targeting cellular metabolism may serve as a novel means of inducing innate immune responses. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The location of splenic NKT cells favours their rapid activation by blood-borne antigen

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Barral, Patricia; Sánchez-Niño, María Dolores; van Rooijen, Nico; Cerundolo, Vincenzo; Batista, Facundo D

2012-01-01

Natural killer T (NKT) cells play an important role in mounting protective responses to blood-borne infections. However, though the spleen is the largest blood filter in the body, the distribution and dynamics of NKT cells within this organ are not well characterized. Here we show that the majority of NKT cells patrol around the marginal zone (MZ) and red pulp (RP) of the spleen. In response to lipid antigen, these NKT cells become arrested and rapidly produce cytokines, while the small proportion of NKT cells located in the white pulp (WP) exhibit limited activation. Importantly, disruption of the splenic MZ by chemical or genetic approaches results in a severe reduction in NKT cell activation indicating the need of cooperation between both MZ macrophages and dendritic cells for efficient NKT cell responses. Thus, the location of splenic NKT cells in the MZ and RP facilitates their access to blood-borne antigen and enables the rapid initiation of protective immune responses. PMID:22505026

The location of splenic NKT cells favours their rapid activation by blood-borne antigen.

Science.gov (United States)

Barral, Patricia; Sánchez-Niño, María Dolores; van Rooijen, Nico; Cerundolo, Vincenzo; Batista, Facundo D

2012-05-16

Natural killer T (NKT) cells play an important role in mounting protective responses to blood-borne infections. However, though the spleen is the largest blood filter in the body, the distribution and dynamics of NKT cells within this organ are not well characterized. Here we show that the majority of NKT cells patrol around the marginal zone (MZ) and red pulp (RP) of the spleen. In response to lipid antigen, these NKT cells become arrested and rapidly produce cytokines, while the small proportion of NKT cells located in the white pulp (WP) exhibit limited activation. Importantly, disruption of the splenic MZ by chemical or genetic approaches results in a severe reduction in NKT cell activation indicating the need of cooperation between both MZ macrophages and dendritic cells for efficient NKT cell responses. Thus, the location of splenic NKT cells in the MZ and RP facilitates their access to blood-borne antigen and enables the rapid initiation of protective immune responses.

Pharmacological inhibition of the chemokine CXCL16 diminishes liver macrophage infiltration and steatohepatitis in chronic hepatic injury.

Directory of Open Access Journals (Sweden)

Alexander Wehr

Full Text Available Non-alcoholic fatty liver disease (NAFLD is a major cause of morbidity and mortality in developed countries, resulting in steatohepatitis (NASH, fibrosis and eventually cirrhosis. Modulating inflammatory mediators such as chemokines may represent a novel therapeutic strategy for NAFLD. We recently demonstrated that the chemokine receptor CXCR6 promotes hepatic NKT cell accumulation, thereby controlling inflammation in experimental NAFLD. In this study, we first investigated human biopsies (n = 20, confirming that accumulation of inflammatory cells such as macrophages is a hallmark of progressive NAFLD. Moreover, CXCR6 gene expression correlated with the inflammatory activity (ALT levels in human NAFLD. We then tested the hypothesis that pharmacological inhibition of CXCL16 might hold therapeutic potential in NAFLD, using mouse models of acute carbon tetrachloride (CCl4- and chronic methionine-choline-deficient (MCD diet-induced hepatic injury. Neutralizing CXCL16 by i.p. injection of anti-CXCL16 antibody inhibited the early intrahepatic NKT cell accumulation upon acute toxic injury in vivo. Weekly therapeutic anti-CXCL16 administrations during the last 3 weeks of 6 weeks MCD diet significantly decreased the infiltration of inflammatory macrophages into the liver and intrahepatic levels of inflammatory cytokines like TNF or MCP-1. Importantly, anti-CXCL16 treatment significantly reduced fatty liver degeneration upon MCD diet, as assessed by hepatic triglyceride levels, histological steatosis scoring and quantification of lipid droplets. Moreover, injured hepatocytes up-regulated CXCL16 expression, indicating that scavenging functions of CXCL16 might be additionally involved in the pathogenesis of NAFLD. Targeting CXCL16 might therefore represent a promising novel therapeutic approach for liver inflammation and steatohepatitis.

Invariant NKT cells regulate experimental autoimmune uveitis through inhibition of Th17 differentiation.

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Oh, Keunhee; Byoun, Ok-Jin; Ham, Don-Il; Kim, Yon Su; Lee, Dong-Sup

2011-02-01

Although NKT cells have been implicated in diverse immunomodulatory responses, the effector mechanisms underlying the NKT cell-mediated regulation of pathogenic T helper cells are not well understood. Here, we show that invariant NKT cells inhibited the differentiation of CD4(+) T cells into Th17 cells both in vitro and in vivo. The number of IL-17-producing CD4(+) T cells was reduced following co-culture with purified NK1.1(+) TCR(+) cells from WT, but not from CD1d(-/-) or Jα18(-/-) , mice. Co-cultured NKT cells from either cytokine-deficient (IL-4(-/-) , IL-10(-/-) , or IFN-γ(-/-) ) or WT mice efficiently inhibited Th17 differentiation. The contact-dependent mechanisms of NKT cell-mediated regulation of Th17 differentiation were confirmed using transwell co-culture experiments. On the contrary, the suppression of Th1 differentiation was dependent on IL-4 derived from the NKT cells. The in vivo regulatory capacity of NKT cells on Th17 cells was confirmed using an experimental autoimmune uveitis model induced with human IRBP(1-20) (IRBP, interphotoreceptor retinoid-binding protein) peptide. NKT cell-deficient mice (CD1d(-/-) or Jα18(-/-) ) demonstrated an increased disease severity, which was reversed by the transfer of WT or cytokine-deficient (IL-4(-/-) , IL-10(-/-) , or IFN-γ(-/-) ) NKT cells. Our results indicate that invariant NKT cells inhibited autoimmune uveitis predominantly through the cytokine-independent inhibition of Th17 differentiation. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CD1d-Restricted Type II NKT Cells Reactive With Endogenous Hydrophobic Peptides.

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Nishioka, Yusuke; Masuda, Sakiko; Tomaru, Utano; Ishizu, Akihiro

2018-01-01

NKT cells belong to a distinct subset of T cells that recognize hydrophobic antigens presented by major histocompatibility complex class I-like molecules, such as CD1d. Because NKT cells stimulated by antigens can activate or suppress other immunocompetent cells through an immediate production of a large amount of cytokines, they are regarded as immunological modulators. CD1d-restricted NKT cells are classified into two subsets, namely, type I and type II. CD1d-restricted type I NKT cells express invariant T cell receptors (TCRs) and react with lipid antigens, including the marine sponge-derived glycolipid α-galactosylceramide. On the contrary, CD1d-restricted type II NKT cells recognize a wide variety of antigens, including glycolipids, phospholipids, and hydrophobic peptides, by their diverse TCRs. In this review, we focus particularly on CD1d-restricted type II NKT cells that recognize endogenous hydrophobic peptides presented by CD1d. Previous studies have demonstrated that CD1d-restricted type I NKT cells usually act as pro-inflammatory cells but sometimes behave as anti-inflammatory cells. It has been also demonstrated that CD1d-restricted type II NKT cells play opposite roles to CD1d-restricted type I NKT cells; thus, they function as anti-inflammatory or pro-inflammatory cells depending on the situation. In line with this, CD1d-restricted type II NKT cells that recognize type II collagen peptide have been demonstrated to act as anti-inflammatory cells in diverse inflammation-induction models in mice, whereas pro-inflammatory CD1d-restricted type II NKT cells reactive with sterol carrier protein 2 peptide have been demonstrated to be involved in the development of small vessel vasculitis in rats.

NKT cells as an ideal anti-tumor immunotherapeutic.

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Fujii, Shin-Ichiro; Shimizu, Kanako; Okamoto, Yoshitaka; Kunii, Naoki; Nakayama, Toshinori; Motohashi, Shinichiro; Taniguchi, Masaru

2013-12-02

Human natural killer T (NKT) cells are characterized by their expression of an invariant T cell antigen receptor α chain variable region encoded by a Vα24Jα18 rearrangement. These NKT cells recognize α-galactosylceramide (α-GalCer) in conjunction with the MHC class I-like CD1d molecule and bridge the innate and acquired immune systems to mediate efficient and augmented immune responses. A prime example of one such function is adjuvant activity: NKT cells augment anti-tumor responses because they can rapidly produce large amounts of IFN-γ, which acts on NK cells to eliminate MHC negative tumors and also on CD8 cytotoxic T cells to kill MHC positive tumors. Thus, upon administration of α-GalCer-pulsed DCs, both MHC negative and positive tumor cells can be effectively eliminated, resulting in complete tumor eradication without tumor recurrence. Clinical trials have been completed in a cohort of 17 patients with advanced non-small cell lung cancers and 10 cases of head and neck tumors. Sixty percent of advanced lung cancer patients with high IFN-γ production had significantly prolonged median survival times of 29.3 months with only the primary treatment. In the case of head and neck tumors, 10 patients who completed the trial all had stable disease or partial responses 5 weeks after the combination therapy of α-GalCer-DCs and activated NKT cells. We now focus on two potential powerful treatment options for the future. One is to establish artificial adjuvant vector cells containing tumor mRNA and α-GalCer/CD1d. This stimulates host NKT cells followed by DC maturation and NK cell activation but also induces tumor-specific long-term memory CD8 killer T cell responses, suppressing tumor metastasis even 1 year after the initial single injection. The other approach is to establish induced pluripotent stem (iPS) cells that can generate unlimited numbers of NKT cells with adjuvant activity. Such iPS-derived NKT cells produce IFN-γ in vitro and in vivo upon

B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction

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Shin, Jung Hoon; Park, Se-Ho

2013-01-01

CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although ?-galactosylceramide (?-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-? by NKT cells, concomitant with a d...

CD8(+)NKT-like cells regulate the immune response by killing antigen-bearing DCs.

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Wang, Chao; Liu, Xi; Li, Zhengyuan; Chai, Yijie; Jiang, Yunfeng; Wang, Qian; Ji, Yewei; Zhu, Zhongli; Wan, Ying; Yuan, Zhenglong; Chang, Zhijie; Zhang, Minghui

2015-09-15

CD1d-dependent NKT cells have been extensively studied; however, the function of CD8(+)NKT-like cells, which are CD1d-independent T cells with NK markers, remains unknown. Here, we report that CD1d-independent CD8(+)NKT-like cells, which express both T cell markers (TCRβ and CD3) and NK cell receptors (NK1.1, CD49b and NKG2D), are activated and significantly expanded in mice immunized with GFP-expressing dendritic cells. Distinct from CD1d-dependent NKT cells, CD8(+)NKT-like cells possess a diverse repertoire of TCRs and secrete high levels of IFN-gamma but not IL-4. CD8(+)NKT-like cell development is normal in CD1d(-/-) mice, which suggests that CD8(+)NKT-like cells undergo a unique development pathway that differs from iNKT cells. Further functional analyses show that CD8(+)NKT-like cells suppress T-cell responses through elimination of dendritic cells in an antigen-specific manner. Adoptive transfer of antigen-specific CD8(+)NKT-like cells into RIP-OVA mice prevented subsequent development of diabetes in the animals induced by activated OT-I CD8 T cells. Our study suggests that CD8(+)NKT-like cells can function as antigen-specific suppressive cells to regulate the immune response through killing antigen-bearing DCs. Antigen-specific down regulation may provide an active and precise method for constraining an excessive immune response and avoiding bypass suppression of necessary immune responses to other antigens.

CD8+NKT-like cells regulate the immune response by killing antigen-bearing DCs

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Wang, Chao; Liu, Xi; Li, Zhengyuan; Chai, Yijie; Jiang, Yunfeng; Wang, Qian; Ji, Yewei; Zhu, Zhongli; Wan, Ying; Yuan, Zhenglong; Chang, Zhijie; Zhang, Minghui

2015-01-01

CD1d-dependent NKT cells have been extensively studied; however, the function of CD8+NKT-like cells, which are CD1d-independent T cells with NK markers, remains unknown. Here, we report that CD1d-independent CD8+NKT-like cells, which express both T cell markers (TCRβ and CD3) and NK cell receptors (NK1.1, CD49b and NKG2D), are activated and significantly expanded in mice immunized with GFP-expressing dendritic cells. Distinct from CD1d-dependent NKT cells, CD8+NKT-like cells possess a diverse repertoire of TCRs and secrete high levels of IFN-gamma but not IL-4. CD8+NKT-like cell development is normal in CD1d−/− mice, which suggests that CD8+NKT-like cells undergo a unique development pathway that differs from iNKT cells. Further functional analyses show that CD8+NKT-like cells suppress T-cell responses through elimination of dendritic cells in an antigen-specific manner. Adoptive transfer of antigen-specific CD8+NKT-like cells into RIP-OVA mice prevented subsequent development of diabetes in the animals induced by activated OT-I CD8 T cells. Our study suggests that CD8+NKT-like cells can function as antigen-specific suppressive cells to regulate the immune response through killing antigen-bearing DCs. Antigen-specific down regulation may provide an active and precise method for constraining an excessive immune response and avoiding bypass suppression of necessary immune responses to other antigens. PMID:26369936

Alleviation of lipopolysaccharide/d-galactosamine-induced liver injury in leukocyte cell-derived chemotaxin 2 deficient mice

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Akinori Okumura

2017-12-01

Full Text Available Leukocyte cell-derived chemotaxin 2 (LECT2 is a secreted pleiotropic protein that is mainly produced by the liver. We have previously shown that LECT2 plays an important role in the pathogenesis of inflammatory liver diseases. Lipopolysaccharide/d-galactosamine (LPS/d-GalN-induced acute liver injury is a known animal model of fulminant hepatic failure. Here we found that this hepatic injury was alleviated in LECT2-deficient mice. The levels of TNF-α and IFN-γ, which mediate this hepatitis, had significantly decreased in these mice, with the decrease in IFN-γ production notably greater than that in TNF-α. We therefore analyzed IFN-γ-producing cells in liver mononuclear cells. Flow cytometric analysis showed significantly reduced IFN-γ production in hepatic NK and NKT cells in LECT2-deficient mice compared with in wild-type mice. We also demonstrated a decrease in IFN-γ production in LECT2-deficient mice after systemic administration of recombinant IL-12, which is known to induce IFN-γ in NK and NKT cells. These results indicate that a decrease of IFN-γ production in NK and NKT cells was involved in the alleviation of LPS/d-GalN-induced liver injury in LECT2-deficient mice.

The Function of CD3+CD56+ NKT-Like Cells in HIV-Infected Individuals

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Yongjun Jiang

2014-01-01

Full Text Available CD3+CD56+ NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs, chronic HIV-infected individuals (CHIs, long-term nonprogressors (LTNPs, and HIV-negative controls (NCs. The results showed that the percentage of IFN-γ+CD3+CD56+ NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3+CD56+ NKT-like cells with dual function (IFN-γ+CD107a+ NKT-like cells in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ+CD107a+ NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3+CD56+ NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

The function of CD3+CD56+ NKT-like cells in HIV-infected individuals.

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Jiang, Yongjun; Cui, Xiaojian; Cui, Chen; Zhang, Jian; Zhou, Fangyuan; Zhang, Zining; Fu, Yajing; Xu, Junjie; Chu, Zhenxing; Liu, Jing; Han, Xiaoxu; Liao, Christina; Wang, Yanan; Cao, Yaming; Shang, Hong

2014-01-01

CD3(+)CD56(+) NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs), chronic HIV-infected individuals (CHIs), long-term nonprogressors (LTNPs), and HIV-negative controls (NCs). The results showed that the percentage of IFN-γ(+)CD3(+)CD56(+) NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3(+)CD56(+) NKT-like cells with dual function (IFN-γ(+)CD107a(+) NKT-like cells) in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ(+)CD107a(+) NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3(+)CD56(+) NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

Programmed death-1 receptor suppresses γ-IFN producing NKT cells in human tuberculosis.

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Singh, Amar; Dey, Aparajit Ballav; Mohan, Anant; Mitra, Dipendra Kumar

2014-05-01

IFN-γ biased Th1 effector immune response is crucial for containment of Mycobacterium tuberculosis infection. Various T cell subsets with regulatory function dictate the generation of Th1 like cells. NKT cells are a specialized T cell subset known to be activated early in immune response and control T cell response via release of immunoregulatory cytokines like IFN-γ, IL-4 and IL-10. M. tuberculosis, with abundance of its cell wall lipids may potently activate NKT cells resulting in cytokine production and PD-1 expression. In this study, among 49 treatment naive active pulmonary tuberculosis patients, we found a higher percentage of PD1(+) NKT cells correlating with sputum bacillary load. Furthermore, blocking PD-1 increased the number of IFN-γ producing NKT cells by inhibiting their apoptosis. Moreover, peripheral frequency of NKT cells declined with therapy suggesting their role in host T cell response. In this study, we concluded that PD-1 preferentially induces apoptosis of IFN-γ producing NKT cells while sparing NKT cells that produce IL-4. Such a polarized NKT cell function may impose a Th2 bias on the ensuing effector T cell response leading to inefficient clearance of M. tuberculosis. Inhibiting PD-1 may therefore alter the T cell response in favor of the host by rescuing type 1 NKT cells from apoptosis and boosting Th1 effector T cell functions against M. tuberculosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Therapeutic efficacy of human hepatocyte transplantation in a SCID/uPA mouse model with inducible liver disease.

Directory of Open Access Journals (Sweden)

Donna N Douglas

2010-02-01

Full Text Available Severe Combined Immune Deficient (SCID/Urokinase-type Plasminogen Activator (uPA mice undergo liver failure and are useful hosts for the propagation of transplanted human hepatocytes (HH which must compete with recipient-derived hepatocytes for replacement of the diseased liver parenchyma. While partial replacement by HH has proven useful for studies with Hepatitis C virus, complete replacement of SCID/uPA mouse liver by HH has never been achieved and limits the broader application of these mice for other areas of biomedical research. The herpes simplex virus type-1 thymidine kinase (HSVtk/ganciclovir (GCV system is a powerful tool for cell-specific ablation in transgenic animals. The aim of this study was to selectively eliminate murine-derived parenchymal liver cells from humanized SCID/uPA mouse liver in order to achieve mice with completely humanized liver parenchyma. Thus, we reproduced the HSVtk (vTK/GCV system of hepatic failure in SCID/uPA mice.In vitro experiments demonstrated efficient killing of vTK expressing hepatoma cells after GCV treatment. For in vivo experiments, expression of vTK was targeted to the livers of FVB/N and SCID/uPA mice. Hepatic sensitivity to GCV was first established in FVB/N mice since these mice do not undergo liver failure inherent to SCID/uPA mice. Hepatic vTK expression was found to be an integral component of GCV-induced pathologic and biochemical alterations and caused death due to liver dysfunction in vTK transgenic FVB/N and non-transplanted SCID/uPA mice. In SCID/uPA mice with humanized liver, vTK/GCV caused death despite extensive replacement of the mouse liver parenchyma with HH (ranging from 32-87%. Surprisingly, vTK/GCV-dependent apoptosis and mitochondrial aberrations were also localized to bystander vTK-negative HH.Extensive replacement of mouse liver parenchyma by HH does not provide a secure therapeutic advantage against vTK/GCV-induced cytotoxicity targeted to residual mouse hepatocytes

Adjuvant effects of therapeutic glycolipids administered to a cohort of NKT cell-diverse pigs.

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Artiaga, Bianca L; Whitener, Robert L; Staples, Charles R; Driver, John P

2014-11-15

CD1d-restricted natural killer T (NKT) cells are a unique lymphocyte population that makes important contributions to host defense against numerous microbial pathogens. The powerful immunomodulatory effects of these cells can be exploited in mice by cognate antigens for multiple therapeutic purposes, including for protection from infectious diseases and as adjuvants to improve vaccines against microbial organisms. These applications have potential to treat and prevent infectious diseases in livestock species that express NKT cells, including pigs. In this study, immune tissues from commercial swine of mixed genetic background were compared for NKT cell frequency, cytokine secretion and subset ratios. Pigs were also injected with the model antigen hen-egg lysozyme (HEL) in conjunction with one of three glycosphingolipids, alpha-galactosylceramide (αGC), OCH and C-glycoside that selectively activate NKT cells, to assess the adjuvant potential of each. There was significant variation between individual pigs for all NKT cell parameters measured. The NKT cell agonists elicited HEL-specific immune responses of different quality, but only αGC increased the systemic concentration of NKT cells. Peripheral blood NKT cell frequency measured prior to treatment was a poor predictor of how individual animals responded to NKT cell therapy. However, our results show that although NKT cells vary considerably between pigs, there exists considerable potential to harness these cells to protect swine from infectious diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

The Janus Face of NKT Cell Function in Autoimmunity and Infectious Diseases

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Alessandra Torina

2018-02-01

Full Text Available Natural killer T cells (NKT are a subset of T lymphocytes bridging innate and adaptive immunity. These cells recognize self and microbial glycolipids bound to non-polymorphic and highly conserved CD1d molecules. Three NKT cell subsets, type I, II, and NKT-like expressing different antigen receptors (TCR were described and TCR activation promotes intracellular events leading to specific functional activities. NKT can exhibit different functions depending on the secretion of soluble molecules and the interaction with other cell types. NKT cells act as regulatory cells in the defense against infections but, on the other hand, their effector functions can be involved in the pathogenesis of several inflammatory disorders due to their exposure to different microbial or self-antigens, respectively. A deep understanding of the biology and functions of type I, II, and NKT-like cells as well as their interplay with cell types acting in innate (neuthrophils, innate lymphoid cells, machrophages, and dendritic cells and adaptive immunity (CD4+,CD8+, and double negative T cells should be important to design potential immunotherapies for infectious and autoimmune diseases.

IL-15 protects NKT cells from inhibition by tumor-associated macrophages and enhances antimetastatic activity

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Liu, Daofeng; Song, Liping; Wei, Jie; Courtney, Amy N.; Gao, Xiuhua; Marinova, Ekaterina; Guo, Linjie; Heczey, Andras; Asgharzadeh, Shahab; Kim, Eugene; Dotti, Gianpietro; Metelitsa, Leonid S.

2012-01-01

Vα24-invariant NKT cells inhibit tumor growth by targeting tumor-associated macrophages (TAMs). Tumor progression therefore requires that TAMs evade NKT cell activity through yet-unknown mechanisms. Here we report that a subset of cells in neuroblastoma (NB) cell lines and primary tumors expresses membrane-bound TNF-α (mbTNF-α). These proinflammatory tumor cells induced production of the chemokine CCL20 from TAMs via activation of the NF-κB signaling pathway, an effect that was amplified in hypoxia. Flow cytometry analyses of human primary NB tumors revealed selective accumulation of CCL20 in TAMs. Neutralization of the chemokine inhibited in vitro migration of NKT cells toward tumor-conditioned hypoxic monocytes and localization of NKT cells to NB grafts in mice. We also found that hypoxia impaired NKT cell viability and function. Thus, CCL20-producing TAMs served as a hypoxic trap for tumor-infiltrating NKT cells. IL-15 protected antigen-activated NKT cells from hypoxia, and transgenic expression of IL-15 in adoptively transferred NKT cells dramatically enhanced their antimetastatic activity in mice. Thus, tumor-induced chemokine production in hypoxic TAMs and consequent chemoattraction and inhibition of NKT cells represents a mechanism of immune escape that can be reversed by adoptive immunotherapy with IL-15–transduced NKT cells. PMID:22565311

IL-15 protects NKT cells from inhibition by tumor-associated macrophages and enhances antimetastatic activity.

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Liu, Daofeng; Song, Liping; Wei, Jie; Courtney, Amy N; Gao, Xiuhua; Marinova, Ekaterina; Guo, Linjie; Heczey, Andras; Asgharzadeh, Shahab; Kim, Eugene; Dotti, Gianpietro; Metelitsa, Leonid S

2012-06-01

Vα24-invariant NKT cells inhibit tumor growth by targeting tumor-associated macrophages (TAMs). Tumor progression therefore requires that TAMs evade NKT cell activity through yet-unknown mechanisms. Here we report that a subset of cells in neuroblastoma (NB) cell lines and primary tumors expresses membrane-bound TNF-α (mbTNF-α). These proinflammatory tumor cells induced production of the chemokine CCL20 from TAMs via activation of the NF-κB signaling pathway, an effect that was amplified in hypoxia. Flow cytometry analyses of human primary NB tumors revealed selective accumulation of CCL20 in TAMs. Neutralization of the chemokine inhibited in vitro migration of NKT cells toward tumor-conditioned hypoxic monocytes and localization of NKT cells to NB grafts in mice. We also found that hypoxia impaired NKT cell viability and function. Thus, CCL20-producing TAMs served as a hypoxic trap for tumor-infiltrating NKT cells. IL-15 protected antigen-activated NKT cells from hypoxia, and transgenic expression of IL-15 in adoptively transferred NKT cells dramatically enhanced their antimetastatic activity in mice. Thus, tumor-induced chemokine production in hypoxic TAMs and consequent chemoattraction and inhibition of NKT cells represents a mechanism of immune escape that can be reversed by adoptive immunotherapy with IL-15-transduced NKT cells.

Activated NKT cells imprint NK-cell differentiation, functionality and education.

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Riese, Peggy; Trittel, Stephanie; May, Tobias; Cicin-Sain, Luka; Chambers, Benedict J; Guzmán, Carlos A

2015-06-01

NK cells represent a vital component of the innate immune system. The recent discoveries demonstrating that the functionality of NK cells depends on their differentiation and education status underscore their potential as targets for immune intervention. However, to exploit their full potential, a detailed understanding of the cellular interactions involved in these processes is required. In this regard, the cross-talk between NKT cells and NK cells needs to be better understood. Our results provide strong evidence for NKT cell-induced effects on key biological features of NK cells. NKT-cell activation results in the generation of highly active CD27(high) NK cells with improved functionality. In this context, degranulation activity and IFNγ production were mainly detected in the educated subset. In a mCMV infection model, we also demonstrated that NKT-cell stimulation induced the generation of highly functional educated and uneducated NK cells, crucial players in viral control. Thus, our findings reveal new fundamental aspects of the NKT-NK cell axis that provide important hints for the manipulation of NK cells in clinical settings. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of a qPCR method to rapidly assess the function of NKT cells.

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Sohn, Silke; Tiper, Irina; Japp, Emily; Sun, Wenji; Tkaczuk, Katherine; Webb, Tonya J

2014-05-01

NKT cells comprise a rare, but important subset of T cells which account for ~0.2% of the total circulating T cell population. NKT cells are known to have anti-tumor functions and rapidly produce high levels of cytokines following activation. Several clinical trials have sought to exploit the effector functions of NKT cells. While some studies have shown promise, NKT cells are approximately 50% lower in cancer patients compared to healthy donors of the same age and gender, thus limiting their therapeutic efficacy. These studies indicate that baseline levels of activation should be assessed before initiating an NKT cell based immunotherapeutic strategy. The goal of this study was to develop a sensitive method to rapidly assess NKT cell function. We utilized artificial antigen presenting cells in combination with qPCR in order to determine NKT cell function in peripheral blood mononuclear cells from healthy donors and breast cancer patients. We found that NKT cell activation can be detected by qPCR, but not by ELISA, in healthy donors as well as in breast cancer patients following four hour stimulation. This method utilizing CD1d-expressing aAPCs will enhance our knowledge of NKT cell biology and could potentially be used as a novel tool in adoptive immunotherapeutic strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

iNKT cell cytotoxic responses control T-lymphoma growth in vitro and in vivo

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Bassiri, Hamid; Das, Rupali; Guan, Peng; Barrett, David M.; Brennan, Patrick J.; Banerjee, Pinaki P.; Wiener, Susan J.; Orange, Jordan S.; Brenner, Michael B.; Grupp, Stephan A.; Nichols, Kim E.

2013-01-01

Invariant natural killer T (iNKT) cells comprise a lineage of CD1d-restricted glycolipid-reactive T lymphocytes with important roles in host immunity to cancer. iNKT cells indirectly participate in antitumor responses by inducing dendritic cell maturation and producing cytokines that promote tumor clearance by CD8+ T and NK cells. Although iNKT cells thereby act as potent cellular adjuvants, it is less clear whether they directly control the growth of tumors. To gain insights into the direct contribution of iNKT cells to tumor immune surveillance, we developed in vitro and in vivo systems to selectively examine the antitumor activity of iNKT cells in the absence of other cytolytic effectors. Using the EL4 T-lymphoma cell line as a model, we find that iNKT cells exert robust and specific lysis of tumor cells in vitro in a manner that is differentially-induced by iNKT cell agonists of varying TCR affinities, such as OCH, α-galactosyl ceramide and PBS44. In vitro blockade of CD1d-mediated lipid antigen presentation, disruption of T cell receptor (TCR) signaling, or loss of perforin expression significantly reduce iNKT cell killing. Consistent with these findings, iNKT cell reconstitution of T, B, and NK cell-deficient mice slows EL4 growth in vivo via TCR-CD1d and perforin-dependent mechanisms. Together, these observations establish that iNKT cells are sufficient to control the growth of T-lymphoma in vitro and in vivo. They also suggest that the induction of iNKT cell cytotoxic responses in situ might serve as a more effective strategy to prevent and/or treat CD1d+ cancers, such as T-lymphoma. PMID:24563871

iNKT cell cytotoxic responses control T-lymphoma growth in vitro and in vivo .

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Bassiri, Hamid; Das, Rupali; Guan, Peng; Barrett, David M; Brennan, Patrick J; Banerjee, Pinaki P; Wiener, Susan J; Orange, Jordan S; Brenner, Michael B; Grupp, Stephan A; Nichols, Kim E

2014-01-01

Invariant natural killer T (iNKT) cells comprise a lineage of CD1d-restricted glycolipid-reactive T lymphocytes with important roles in host immunity to cancer. iNKT cells indirectly participate in antitumor responses by inducing dendritic cell maturation and producing cytokines that promote tumor clearance by CD8+ T and NK cells. Although iNKT cells thereby act as potent cellular adjuvants, it is less clear whether they directly control the growth of tumors. To gain insights into the direct contribution of iNKT cells to tumor immune surveillance, we developed in vitro and in vivo systems to selectively examine the antitumor activity of iNKT cells in the absence of other cytolytic effectors. Using the EL4 T-lymphoma cell line as a model, we found that iNKT cells exert robust and specific lysis of tumor cells in vitro in a manner that is differentially induced by iNKT cell agonists of varying T-cell receptor (TCR) affinities, such as OCH, α-galactosyl ceramide, and PBS44. In vitro blockade of CD1d-mediated lipid antigen presentation, disruption of TCR signaling, or loss of perforin expression significantly reduce iNKT cell killing. Consistent with these findings, iNKT cell reconstitution of T, B, and NK cell–deficient mice slows EL4 growth in vivo via TCR-CD1d and perforin-dependent mechanisms. Together, these observations establish that iNKT cells are sufficient to control the growth of T lymphoma in vitro and in vivo. They also suggest that the induction of iNKT cell cytotoxic responses in situ might serve as a more effective strategy to prevent and/or treat CD1d+ cancers, such as T lymphoma. ©2013 AACR.

Rapamycin protects kidney against ischemia reperfusion injury through recruitment of NKT cells.

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Zhang, Chao; Zheng, Long; Li, Long; Wang, Lingyan; Li, Liping; Huang, Shang; Gu, Chenli; Zhang, Lexi; Yang, Cheng; Zhu, Tongyu; Rong, Ruiming

2014-08-19

NKT cells play a protective role in ischemia reperfusion (IR) injury, of which the trafficking in the body and recruitment in injured organs can be influenced by immunosuppressive therapy. Therefore, we investigated the effects of rapamycin on kidneys exposed to IR injury in early stage and on trafficking of NKT cells in a murine model. Balb/c mice were subjected to kidney 30 min ischemia followed by 24 h reperfusion. Rapamycin (2.5 ml/kg) was administered by gavage daily, starting 1 day before the operation. Renal function and histological changes were assessed. The proportion of NKT cells in peripheral blood, spleen and kidney was detected by flow cytometry. The chemokines and corresponding receptor involved in NKT cell trafficking were determined by RT-PCR and flow cytometry respectively. Rapamycin significantly improved renal function and ameliorated histological injury. In rapamycin-treated group, the proportion of NKT cells in spleen was significantly decreased but increased in peripheral blood and kidney. In addition, the CXCR3+ NKT cell in the kidney increased remarkably in the rapamycin-treated group. The chemokines, CXCL9 and CXCL10, as the ligands of CXCR3, were also increased in the rapamycin-treated kidney. Rapamycin may recruit NKT cells from spleen to the IR-induced kidney to ameliorate renal IR injury in the early stage.

CD1d expression and invariant NKT cell responses in herpesvirus infections

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Rusung eTan

2015-06-01

Full Text Available Invariant natural killer T (iNKT cells are a highly conserved subset of unconventional T lymphocytes that express a canonical, semi-invariant T cell receptor (TCR and surface markers shared with the natural killer cell lineage. iNKT cells recognize exogenous and endogenous glycolipid antigens restricted by non-polymorphic CD1d molecules, and are highly responsive to the prototypical agonist, α-galactosylceramide. Upon activation, iNKT cells rapidly coordinate signaling between innate and adaptive immune cells through the secretion of proinflammatory cytokines, leading to the maturation of antigen-presenting cells and expansion of antigen-specific CD4+ and CD8+ T cells. Because of their potent immunoregulatory properties, iNKT cells have been extensively studied and are known to play a pivotal role in mediating immune responses against microbial pathogens including viruses. Here, we review evidence that herpesviruses manipulate CD1d expression to escape iNKT cell surveillance and establish lifelong latency in humans. Collectively, published findings suggest that iNKT cells play critical roles in anti-herpesvirus immune responses and could be harnessed therapeutically to limit viral infection and viral-associated disease.

The Janus Face of NKT Cell Function in Autoimmunity and Infectious Diseases.

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Torina, Alessandra; Guggino, Giuliana; La Manna, Marco Pio; Sireci, Guido

2018-02-01

Natural killer T cells (NKT) are a subset of T lymphocytes bridging innate and adaptive immunity. These cells recognize self and microbial glycolipids bound to non-polymorphic and highly conserved CD1d molecules. Three NKT cell subsets, type I, II, and NKT-like expressing different antigen receptors (TCR) were described and TCR activation promotes intracellular events leading to specific functional activities. NKT can exhibit different functions depending on the secretion of soluble molecules and the interaction with other cell types. NKT cells act as regulatory cells in the defense against infections but, on the other hand, their effector functions can be involved in the pathogenesis of several inflammatory disorders due to their exposure to different microbial or self-antigens, respectively. A deep understanding of the biology and functions of type I, II, and NKT-like cells as well as their interplay with cell types acting in innate (neuthrophils, innate lymphoid cells, machrophages, and dendritic cells) and adaptive immunity (CD4⁺,CD8⁺, and double negative T cells) should be important to design potential immunotherapies for infectious and autoimmune diseases.

Proteomic profiling in incubation medium of mouse, rat and human precision-cut liver slices for biomarker detection regarding acute drug-induced liver injury

NARCIS (Netherlands)

van Swelm, Rachel P L; Hadi, Mackenzie; Laarakkers, Coby M M; Masereeuw, R.|info:eu-repo/dai/nl/155644033; Groothuis, Geny M M; Russel, Frans G M

Drug-induced liver injury is one of the leading causes of drug withdrawal from the market. In this study, we investigated the applicability of protein profiling of the incubation medium of human, mouse and rat precision-cut liver slices (PCLS) exposed to liver injury-inducing drugs for biomarker

The adaptor molecule SAP plays essential roles during invariant NKT cell cytotoxicity and lytic synapse formation.

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Das, Rupali; Bassiri, Hamid; Guan, Peng; Wiener, Susan; Banerjee, Pinaki P; Zhong, Ming-Chao; Veillette, André; Orange, Jordan S; Nichols, Kim E

2013-04-25

The adaptor molecule signaling lymphocytic activation molecule-associated protein (SAP) plays critical roles during invariant natural killer T (iNKT) cell ontogeny. As a result, SAP-deficient humans and mice lack iNKT cells. The strict developmental requirement for SAP has made it difficult to discern its possible involvement in mature iNKT cell functions. By using temporal Cre recombinase-mediated gene deletion to ablate SAP expression after completion of iNKT cell development, we demonstrate that SAP is essential for T-cell receptor (TCR)-induced iNKT cell cytotoxicity against T-cell and B-cell leukemia targets in vitro and iNKT-cell-mediated control of T-cell leukemia growth in vivo. These findings are not restricted to the murine system: silencing RNA-mediated suppression of SAP expression in human iNKT cells also significantly impairs TCR-induced cytolysis. Mechanistic studies reveal that iNKT cell killing requires the tyrosine kinase Fyn, a known SAP-binding protein. Furthermore, SAP expression is required within iNKT cells to facilitate their interaction with T-cell targets and induce reorientation of the microtubule-organizing center to the immunologic synapse (IS). Collectively, these studies highlight a novel and essential role for SAP during iNKT cell cytotoxicity and formation of a functional IS.

Type II NKT Cells and Their Emerging Role in Health and Disease.

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Dhodapkar, Madhav V; Kumar, Vipin

2017-02-01

NKT cells recognize lipid Ags presented by a class I MHC-like molecule CD1d, a member of the CD1 family. Although most initial studies on NKT cells focused on a subset with semi-invariant TCR termed invariant NKT cells, the majority of CD1d-restricted lipid-reactive human T cells express diverse TCRs and are termed type II NKT cells. These cells constitute a distinct population of circulating and tissue-resident effector T cells with immune-regulatory properties. They react to a growing list of self- as well as non-self-lipid ligands, and share some properties with both invariant NKT and conventional T cells. An emerging body of evidence points to their role in the regulation of immunity to pathogens/tumors and in autoimmune/metabolic disorders. An improved understanding of the biology of these cells and the ability to manipulate their function may be of therapeutic benefit in diverse disease conditions. Copyright © 2017 by The American Association of Immunologists, Inc.

B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction.

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Shin, Jung Hoon; Park, Se-Ho

2013-10-01

CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although α-galactosylceramide (α-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-γ by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.

NKT Cells in the Induced Sputum of Severe Asthmatics

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Agnes Hamzaoui

2006-01-01

of the sputum and monoclonal antibodies to CD3, CD4, CD8, CD56, CD25, and TCRγδ. The number of NKT (CD3+CD56+ cells was significantly higher in the sputum of severe asthmatics compared with mild asthmatic and healthy control groups (P<.05. CD8+CD56+ cells were the predominant subtype of the increased NKT cells in severe asthmatics. CD3+CD56+Vα24+, TCRγδ+ CD56+, and CD4+CD25+ T cells were significantly increased in severe asthmatic patients. These results suggest that the immunopathogenesis of severe asthmatics vary between severe and mild asthmatics, and that CD8+CD56+ NKT cells may play an important role in the immunopathogenesis of severe asthma.

The response of CD1d-restricted invariant NKT cells to microbial pathogens and their products

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Luc eVan Kaer

2015-05-01

Full Text Available Invariant natural killer T (iNKT cells become activated during a wide variety of infections. This includes organisms lacking cognate CD1d-binding glycolipid antigens recognized by the semi-invariant T cell receptor of iNKT cells. Additional studies have shown that iNKT cells also become activated in vivo in response to microbial products such as bacterial lipopolysaccharide, a potent inducer of cytokine production in antigen-presenting cells (APCs. Other studies have shown that iNKT cells are highly responsive to stimulation by cytokines such as interleukin-12. These findings have led to the concept that microbial pathogens can activate iNKT cells either directly via glycolipids, or indirectly by inducing cytokine production in APCs. iNKT cells activated in this manner produce multiple cytokines that can influence the outcome of infection, usually in favor of the host, although potent iNKT cell activation may contribute to an uncontrolled cytokine storm and sepsis. One aspect of the response of iNKT cells to microbial pathogens is that it is short-lived and followed by an extended time period of unresponsiveness to reactivation. This refractory period may represent a means to avoid chronic activation and cytokine production by iNKT cells, thus protecting the host against some of the negative effects of iNKT cell activation, but potentially putting the host at risk for secondary infections. These effects of microbial pathogens and their products on iNKT cells are not only important for understanding the role of these cells in immune responses against infections but also for the development of iNKT cell-based therapies.

IL-21 Modulates Activation of NKT Cells in Patients with Stage IV Malignant Melanoma.

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Coquet, Jonathan M; Skak, Kresten; Davis, Ian D; Smyth, Mark J; Godfrey, Dale I

2013-10-01

Interleukin-21 (IL-21) is a common γ-chain cytokine produced by T helper and natural killer T (NKT) cells. It has been shown to regulate the response of various lymphocyte subsets including NK, NKT, T and B cells. Owing to its potent anti-tumor function in preclinical studies and its ability to induce cytotoxicity and interferon-γ (IFN-γ) production in NK and CD8 T cells, recombinant IL-21 (rIL-21) was fast-tracked into early-phase clinical trials of patients with various malignancies. In a phase 2a trial of patients with metastatic melanoma, we analyzed the frequency and function of NKT cells in patients receiving rIL-21. NKT cells were present at a low frequency, but their levels were relatively stable in patients administered rIL-21. Unlike our observations in NK and CD8 T cells, rIL-21 appeared to reduce IFN-γ and TNF production by NKT cells, whereas it enhanced IL-4 production. It also modulated the expression of cell surface markers, specifically on CD4(-) NKT cells. In addition, an increase in CD3(+)CD56(+) NKT-like cells was observed over the course of rIL-21 administration. These results highlight that IL-21 is a potent regulator of NKT cell function in vivo.

A novel method of mouse ex utero transplantation of hepatic progenitor cells into the fetal liver

International Nuclear Information System (INIS)

Shikanai, Mima; Asahina, Kinji; Iseki, Sachiko; Teramoto, Kenichi; Nishida, Tomohiro; Shimizu-Saito, Keiko; Ota, Masato; Eto, Kazuhiro; Teraoka, Hirobumi

2009-01-01

Avoiding the limitations of the adult liver niche, transplantation of hepatic stem/progenitor cells into fetal liver is desirable to analyze immature cells in a hepatic developmental environment. Here, we established a new monitor tool for cell fate of hepatic progenitor cells transplanted into the mouse fetal liver by using ex utero surgery. When embryonic day (ED) 14.5 hepatoblasts were injected into the ED14.5 fetal liver, the transplanted cells expressed albumin abundantly or α-fetoprotein weakly, and contained glycogen in the neonatal liver, indicating that transplanted hepatoblasts can proliferate and differentiate in concord with surrounding recipient parenchymal cells. The transplanted cells became mature in the liver of 6-week-old mice. Furthermore, this method was applicable to transplantation of hepatoblast-like cells derived from mouse embryonic stem cells. These data indicate that this unique technique will provide a new in vivo experimental system for studying cell fate of hepatic stem/progenitor cells and liver organogenesis.

Commensal microbiota and NKT cells in the control of inflammatory diseases at mucosal surfaces.

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Zeissig, Sebastian; Blumberg, Richard S

2013-12-01

Natural Killer T (NKT) cells are a phenotypically and functionally diverse subset of T cells, which recognizes self- and microbial lipids in the context of the atypical MHC class I molecule CD1d. NKT cells exhibit potent effector functions and play critical roles in antimicrobial defense, cancer immunosurveillance and the modulation of immune-mediated disorders. Recent evidence has revealed extensive cross-regulation between the mucosal microbiota and CD1d as well as NKT cells. Microbial exposure at mucosal surfaces, particularly during early postnatal development, regulates NKT cell trafficking and function in the intestine and the lung and determines the susceptibility to NKT cell-mediated inflammatory disorders. Conversely, CD1d controls the composition of the intestinal microbiota; perhaps through the regulation of Paneth cell function. Here, we provide an overview of recent findings on the crosstalk between the microbiota and NKT cells and discuss the implication for mucosal homeostasis and its dysregulation in inflammatory disorders. Copyright © 2013 Elsevier Ltd. All rights reserved.

Discrimination of tumorigenic triazole conazoles from phenobarbital by transcriptional analyses of mouse liver gene expression

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Conazoles are fungicides used to control fungal growth in environmental settings and to treat humans with fungal infections. Mouse hepatotumorigenic conazoles display many of the same hepatic toxicologic responses as the mouse liver carcinogen phenobarbital (PB): constitutive and...

Border Patrol Gone Awry: Lung NKT Cell Activation by Francisella tularensis Exacerbates Tularemia-Like Disease.

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Hill, Timothy M; Gilchuk, Pavlo; Cicek, Basak B; Osina, Maria A; Boyd, Kelli L; Durrant, Douglas M; Metzger, Dennis W; Khanna, Kamal M; Joyce, Sebastian

2015-06-01

The respiratory mucosa is a major site for pathogen invasion and, hence, a site requiring constant immune surveillance. The type I, semi-invariant natural killer T (NKT) cells are enriched within the lung vasculature. Despite optimal positioning, the role of NKT cells in respiratory infectious diseases remains poorly understood. Hence, we assessed their function in a murine model of pulmonary tularemia--because tularemia is a sepsis-like proinflammatory disease and NKT cells are known to control the cellular and humoral responses underlying sepsis. Here we show for the first time that respiratory infection with Francisella tularensis live vaccine strain resulted in rapid accumulation of NKT cells within the lung interstitium. Activated NKT cells produced interferon-γ and promoted both local and systemic proinflammatory responses. Consistent with these results, NKT cell-deficient mice showed reduced inflammatory cytokine and chemokine response yet they survived the infection better than their wild type counterparts. Strikingly, NKT cell-deficient mice had increased lymphocytic infiltration in the lungs that organized into tertiary lymphoid structures resembling induced bronchus-associated lymphoid tissue (iBALT) at the peak of infection. Thus, NKT cell activation by F. tularensis infection hampers iBALT formation and promotes a systemic proinflammatory response, which exacerbates severe pulmonary tularemia-like disease in mice.

CAR-mediated repression of Foxo1 transcriptional activity regulates the cell cycle inhibitor p21 in mouse livers

International Nuclear Information System (INIS)

Kazantseva, Yuliya A.; Yarushkin, Andrei A.; Pustylnyak, Vladimir O.

2014-01-01

Highlights: • CAR activation decreased the level of Foxo1 in mouse livers. • CAR activation decreased the level of p21 in mouse livers. • CAR activation inhibited Foxo1 transcriptional activity in mouse livers. - Abstract: 1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), an agonist of constitutive androstane receptor (CAR), is a well-known strong primary chemical mitogen for the mouse liver. Despite extensive investigation of the role of CAR in the regulation of cell proliferation, our knowledge of the intricate mediating mechanism is incomplete. In this study, we demonstrated that long-term CAR activation by TCPOBOP increased liver-to-body weight ratio and decreased tumour suppressor Foxo1 expression and transcriptional activity, which were correlated with reduced expression of genes regulated by Foxo1, including the cell-cycle inhibitor Cdkn1a(p21), and upregulation of the cell-cycle regulator Cyclin D1. Moreover, we demonstrated the negative regulatory effect of TCPOBOP-activated CAR on the association of Foxo1 with the target Foxo1 itself and Cdkn1a(p21) promoters. Thus, we identified CAR-mediated repression of cell cycle inhibitor p21, as mediated by repression of FOXO1 expression and transcriptional activity. CAR-FOXO1 cross-talk may provide new opportunities for understanding liver diseases and developing more effective therapeutic approaches to better drug treatments

Inhibitory effect of gene combination in a mouse model of colon cancer with liver metastasis.

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DU, Tong; Niu, Hongxin

2014-09-01

The aim of the present study was to establish an animal liver metastasis model with human colon cancer and investigate the inhibitory effect of the wild type (WT) p53 gene combined with thymidine kinase/ganciclovir (TK/GCV) and cytosine deaminase/5-fluorocytosine (CD/5-FC) systems on liver metastasis of colon cancer. A nude mouse liver metastasis model with human colon cancer was established via a spleen cultivation method. A total of 32 nude mice were randomly divided into four groups, each group with eight mice. Group 1 mice received splenic injections of SW480 cells (control group), while group 2 mice were injected with SW480/p53 cells in the spleen. Group 3 mice were administered splenic injections of SW480/TK-CD cells, and GCV and 5-FC were injected into the abdominal cavity. Finally, group 4 mice received splenic injections of SW480/p53 cells mixed in equal proportion with SW480/TK-CD cells, as well as GCV and 5-FC injections in the abdominal cavity. These cells described were constructed in our laboratory and other laboratories. The number of liver metastatic tumors, the liver metastasis rate, conventional pathology, electron microscopy and other indicators in the nude mice of each group were compared and observed. The nude mouse liver metastasis model with human colon cancer was successfully established; the liver metastasis rate of the control group was 100%. The results demonstrated that the rate of liver metastasis in the nude mice in each treatment group decreased, as well as the average number of liver metastatic tumors. Furthermore, the effect of the treatment group with genetic combination (group 4) was the most effective, demonstrating that WTp53 had a synergistic effect with TK/GCV and CD/5-FC. Therefore, the present study successfully established a mouse model of liver metastasis with colon cancer by injecting human colon cancer cells in the spleen. Combined gene therapy was shown to have a synergistic effect, which effectively inhibited the

A mouse radiation-induced liver disease model for stereotactic body radiation therapy validated in patients with hepatocellular carcinoma

International Nuclear Information System (INIS)

Wu, Zhi-Feng; Zhang, Jian-Ying; Shen, Xiao-Yun; Gao, Ya-Bo; Hu, Yong; Zeng, Zhao-Chong; Zhou, Le-Yuan

2016-01-01

Purpose: Lower radiation tolerance of the whole liver hinders dose escalations of stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) treatment. This study was conducted to define the exact doses that result in radiation-induced liver disease (RILD) as well as to determine dose constraints for the critical organs at risk (OARs) in mice; these parameters are still undefined in HCC SBRT. Methods: This study consisted of two phases. In the primary phase, mice treated with helical tomotherapy-based SBRT were stratified according to escalating radiation doses to the livers. The pathological differences, signs [such as mouse performance status (MPS)], and serum aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/albumin levels were observed. Radiation-induced disease severities of the OARs were scored using systematic evaluation standards. In the validation phase in humans, 13 patients with HCC who had undergone radiotherapy before hepatectomy were enrolled to validate RILD pathological changes in a mouse study. Results: The evaluation criteria of the mouse liver radiotherapy-related signs were as follows: MPS ≥ 2.0 ± 0.52, AST/ALT ≥ 589.2 ± 118.5/137.4 ± 15.3 U/L, serum albumin ≤ 16.8 ± 2.29 g/L. The preliminary dose constraints of the OARs were also obtained, such as those for the liver (average dose ≤ 26.36 ± 1.71 Gy) and gastrointestinal tract (maximum dose ≤ 22.63 Gy). Mouse RILD models were able to be developed when the livers were irradiated with average doses of ≥31.76 ± 1.94 Gy (single fraction). RILD pathological changes in mice have also been validated in HCC patients. Conclusions: Mouse RILD models could be developed with SBRT based on the dose constraints for the OARs and evaluation criteria of mouse liver radiotherapy-related signs, and the authors’ results favor the study of further approaches to treat HCC with SBRT.

Peroxisome proliferator activated receptor alpha regulates a male-specific cytochrome P450 in mouse liver.

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Jeffery, Brett; Choudhury, Agharul I; Horley, Neill; Bruce, Mary; Tomlinson, Simon R; Roberts, Ruth A; Gray, Tim J B; Barrett, David A; Shaw, P Nicholas; Kendall, David; Bell, David R

2004-09-15

We set out to find if the strain-specific, male-specific hepatic expression of Cyp4a protein in mouse was due to expression of Cyp4a12 and to understand the genetic basis for reported differences in expression. 12-Lauric acid hydroxylase (LAH) activity was found to show higher levels in male ddY, but not C57Bl/6, mouse liver microsomes. The expression of Cyp4a12 mRNA was studied using RNAase protection assays in male and female liver and kidney of nine mouse strains. Cyp4a12 was found to be highly expressed in male liver and kidney, but at much lower levels in female liver and kidney, in all strains studied. Western blotting with an antibody specific for Cyp4a12 confirmed that Cyp4a12 was expressed in a male specific fashion in C57Bl/6 mouse liver. RNAase protection analysis for Cyp4a10 and 14 in ddY mice revealed that neither of these genes showed male-specific expression. To further investigate genetic factors that control male-specific Cyp4a12 expression, PPARalpha+/+ and -/- mice were studied, showing that total P450 and 12-LAH activity was male-specific in +/+, but not -/- mice. RNAase protection assays were used to confirm that Cyp4a12 was lower in -/- mice. However, the male-specific Slp and MUP-1 genes retained hepatic male-specific levels of expression in +/+ and -/- mice, showing that the decrease in Cyp4a12 was not a general effect on male-specific expression. Thus, PPARalpha has a specific effect on constitutive expression of Cyp4a12.

Phenobarbital induces cell cycle transcriptional responses in mouse liver humanized for constitutive androstane and pregnane x receptors.

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Luisier, Raphaëlle; Lempiäinen, Harri; Scherbichler, Nina; Braeuning, Albert; Geissler, Miriam; Dubost, Valerie; Müller, Arne; Scheer, Nico; Chibout, Salah-Dine; Hara, Hisanori; Picard, Frank; Theil, Diethilde; Couttet, Philippe; Vitobello, Antonio; Grenet, Olivier; Grasl-Kraupp, Bettina; Ellinger-Ziegelbauer, Heidrun; Thomson, John P; Meehan, Richard R; Elcombe, Clifford R; Henderson, Colin J; Wolf, C Roland; Schwarz, Michael; Moulin, Pierre; Terranova, Rémi; Moggs, Jonathan G

2014-06-01

The constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) are closely related nuclear receptors involved in drug metabolism and play important roles in the mechanism of phenobarbital (PB)-induced rodent nongenotoxic hepatocarcinogenesis. Here, we have used a humanized CAR/PXR mouse model to examine potential species differences in receptor-dependent mechanisms underlying liver tissue molecular responses to PB. Early and late transcriptomic responses to sustained PB exposure were investigated in liver tissue from double knock-out CAR and PXR (CAR(KO)-PXR(KO)), double humanized CAR and PXR (CAR(h)-PXR(h)), and wild-type C57BL/6 mice. Wild-type and CAR(h)-PXR(h) mouse livers exhibited temporally and quantitatively similar transcriptional responses during 91 days of PB exposure including the sustained induction of the xenobiotic response gene Cyp2b10, the Wnt signaling inhibitor Wisp1, and noncoding RNA biomarkers from the Dlk1-Dio3 locus. Transient induction of DNA replication (Hells, Mcm6, and Esco2) and mitotic genes (Ccnb2, Cdc20, and Cdk1) and the proliferation-related nuclear antigen Mki67 were observed with peak expression occurring between 1 and 7 days PB exposure. All these transcriptional responses were absent in CAR(KO)-PXR(KO) mouse livers and largely reversible in wild-type and CAR(h)-PXR(h) mouse livers following 91 days of PB exposure and a subsequent 4-week recovery period. Furthermore, PB-mediated upregulation of the noncoding RNA Meg3, which has recently been associated with cellular pluripotency, exhibited a similar dose response and perivenous hepatocyte-specific localization in both wild-type and CAR(h)-PXR(h) mice. Thus, mouse livers coexpressing human CAR and PXR support both the xenobiotic metabolizing and the proliferative transcriptional responses following exposure to PB.

Temporal Regulation of Natural Killer T Cell Interferon Gamma Responses by β-Catenin-Dependent and -Independent Wnt Signaling

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Jessica C. Kling

2018-03-01

Full Text Available Natural killer T (NKT cells are prominent innate-like lymphocytes in the liver with critical roles in immune responses during infection, cancer, and autoimmunity. Interferon gamma (IFN-γ and IL-4 are key cytokines rapidly produced by NKT cells upon recognition of glycolipid antigens presented by antigen-presenting cells (APCs. It has previously been reported that the transcriptional coactivator β-catenin regulates NKT cell differentiation and functionally biases NKT cell responses toward IL-4, at the expense of IFN-γ production. β-Catenin is not only a central effector of Wnt signaling but also contributes to other signaling networks. It is currently unknown whether Wnt ligands regulate NKT cell functions. We thus investigated how Wnt ligands and β-catenin activity shape liver NKT cell functions in vivo in response to the glycolipid antigen, α-galactosylceramide (α-GalCer using a mouse model. Pharmacologic targeting of β-catenin activity with ICG001, as well as myeloid-specific genetic ablation of Wntless (Wls, to specifically target Wnt protein release by APCs, enhanced early IFN-γ responses. By contrast, within several hours of α-GalCer challenge, myeloid-specific Wls deficiency, as well as pharmacologic targeting of Wnt release using the small molecule inhibitor IWP-2 impaired α-GalCer-induced IFN-γ responses, independent of β-catenin activity. These data suggest that myeloid cell-derived Wnt ligands drive early Wnt/β-catenin signaling that curbs IFN-γ responses, but that, subsequently, Wnt ligands sustain IFN-γ expression independent of β-catenin activity. Our analyses in ICG001-treated mice confirmed a role for β-catenin activity in driving early IL-4 responses by liver NKT cells. However, neither pharmacologic nor genetic perturbation of Wnt production affected the IL-4 response, suggesting that IL-4 production by NKT cells in response to α-GalCer is not driven by released Wnt ligands. Collectively, these data reveal

Temporal Regulation of Natural Killer T Cell Interferon Gamma Responses by β-Catenin-Dependent and -Independent Wnt Signaling.

Science.gov (United States)

Kling, Jessica C; Jordan, Margaret A; Pitt, Lauren A; Meiners, Jana; Thanh-Tran, Thao; Tran, Le Son; Nguyen, Tam T K; Mittal, Deepak; Villani, Rehan; Steptoe, Raymond J; Khosrotehrani, Kiarash; Berzins, Stuart P; Baxter, Alan G; Godfrey, Dale I; Blumenthal, Antje

2018-01-01

Natural killer T (NKT) cells are prominent innate-like lymphocytes in the liver with critical roles in immune responses during infection, cancer, and autoimmunity. Interferon gamma (IFN-γ) and IL-4 are key cytokines rapidly produced by NKT cells upon recognition of glycolipid antigens presented by antigen-presenting cells (APCs). It has previously been reported that the transcriptional coactivator β-catenin regulates NKT cell differentiation and functionally biases NKT cell responses toward IL-4, at the expense of IFN-γ production. β-Catenin is not only a central effector of Wnt signaling but also contributes to other signaling networks. It is currently unknown whether Wnt ligands regulate NKT cell functions. We thus investigated how Wnt ligands and β-catenin activity shape liver NKT cell functions in vivo in response to the glycolipid antigen, α-galactosylceramide (α-GalCer) using a mouse model. Pharmacologic targeting of β-catenin activity with ICG001, as well as myeloid-specific genetic ablation of Wntless (Wls) , to specifically target Wnt protein release by APCs, enhanced early IFN-γ responses. By contrast, within several hours of α-GalCer challenge, myeloid-specific Wls deficiency, as well as pharmacologic targeting of Wnt release using the small molecule inhibitor IWP-2 impaired α-GalCer-induced IFN-γ responses, independent of β-catenin activity. These data suggest that myeloid cell-derived Wnt ligands drive early Wnt/β-catenin signaling that curbs IFN-γ responses, but that, subsequently, Wnt ligands sustain IFN-γ expression independent of β-catenin activity. Our analyses in ICG001-treated mice confirmed a role for β-catenin activity in driving early IL-4 responses by liver NKT cells. However, neither pharmacologic nor genetic perturbation of Wnt production affected the IL-4 response, suggesting that IL-4 production by NKT cells in response to α-GalCer is not driven by released Wnt ligands. Collectively, these data reveal complex temporal

SAP expression in invariant NKT cells is required for cognate help to support B-cell responses.

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Detre, Cynthia; Keszei, Marton; Garrido-Mesa, Natividad; Kis-Toth, Katalin; Castro, Wilson; Agyemang, Amma F; Veerapen, Natacha; Besra, Gurdyal S; Carroll, Michael C; Tsokos, George C; Wang, Ninghai; Leadbetter, Elizabeth A; Terhorst, Cox

2012-07-05

One of the manifestations of X-linked lymphoproliferative disease (XLP) is progressive agammaglobulinemia, caused by the absence of a functional signaling lymphocyte activation molecule (SLAM)-associated protein (SAP) in T, invariant natural killer T (NKT) cells and NK cells. Here we report that α-galactosylceramide (αGalCer) activated NKT cells positively regulate antibody responses to haptenated protein antigens at multiple checkpoints, including germinal center formation and affinity maturation. Whereas NKT cell-dependent B cell responses were absent in SAP(-/-).B6 mice that completely lack NKT cells, the small number of SAP-deficient NKT cells in SAP(-/-).BALB/c mice adjuvated antibody production, but not the germinal center reaction. To test the hypothesis that SAP-deficient NKT cells can facilitate humoral immunity, SAP was deleted after development in SAP(fl/fl).tgCreERT2.B6 mice. We find that NKT cell intrinsic expression of SAP is dispensable for noncognate helper functions, but is critical for providing cognate help to antigen-specific B cells. These results demonstrate that SLAM-family receptor-regulated cell-cell interactions are not limited to T-B cell conjugates. We conclude that in the absence of SAP, several routes of NKT cell-mediated antibody production are still accessible. The latter suggests that residual NKT cells in XLP patients might contribute to variations in dysgammaglobulinemia.

[Phenotypic and functional features of NK and NKT cells in chronic hepatitis B].

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Wu, Shaofei; Li, Man; Sun, Xuehua; Zhou, Zhenhua; Zhu, Xiaojun; Zhang, Xin; Gao, Yueqiu

2015-06-01

To detect the ratio of natural killer (NK)/natural killer T (NKT) cells in peripheral blood, the levels of NKG2D/NKG2A, interferon γ (IFN-γ) and tumor necrosis factor α (TNF-α) in patients with chronic hepatitis B (CHB). Peripheral blood mononuclear cells (PBMCs) were harvested from CHB patients. The ratio of NK/NKT cells in PBMCs and the levels of NKG2D and NKG2A were detected by flow cytometry. The expressions of intracellular IFN-γ and TNF-α were analyzed by flow cytometry after the treatment with phorbol 12-myristate 13-acetate (PMA), brefeldin A (BFA) or ionomycin in vitro. The comparison between two groups was performed by independent sample t-test. The relationship of each index to hepatitis B virus load and serum alanine aminotransferase was analyzed by Pearson correlation analysis. Compared with healthy controls, CHB patients presented with significantly decreased peripheral blood NK/NKT cell ratio and significantly elevated proportions of NKG2A+ NK and NKG2A+NKT cells, and after the treatment with PMA/BFA/ionomycin, IFN-γ+ NK and IFN-γ+ NKT cells were significantly reduced in CHB patients. NK and NKT cells showed a reduced ratio, disordered receptor expressions and decreased cytokine secretion capacity in CHB patients.

Alcohol facilitates CD1d loading, subsequent activation of NKT cells, and reduces the incidence of diabetes in NOD mice.

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Karsten Buschard

Full Text Available BACKGROUND: Ethanol ('alcohol' is a partly hydrophobic detergent that may affect the accessibility of glycolipids thereby influencing immunological effects of these molecules. METHODS: The study included cellular in vitro tests using α-galactosylceramide (αGalCer, and in vivo NOD mice experiments detecting diabetes incidence and performing behavioural and bacterial analyses. RESULTS: Alcohol in concentrations from 0.6% to 2.5% increased IL-2 production from NKT cells stimulated with αGalCer by 60% (p<0.05. CD1d expressed on HeLa cells contained significantly increasing amounts of αGalCer with increasing concentrations of alcohol, suggesting that alcohol facilitated the passive loading of αGalCer to CD1d. NOD mice were found to tolerate 5% ethanol in their drinking water without signs of impairment in liver function. Giving this treatment, the diabetes incidence declined significantly. Higher numbers of CD3+CD49b+ NKT cells were found in spleen and liver of the alcohol treated compared to the control mice (p<0.05, whereas the amount of CD4+Foxp3+ regulator T cells did not differ. Increased concentrations of IFN-γ were detected in 24-hour blood samples of alcohol treated mice. Behavioural studies showed no change in attitude of the ethanol-consuming mice, and bacterial composition of caecum samples was not affected by alcohol, disqualifying these as protective mechanisms. CONCLUSION: Alcohol facilitates the uptake of glycolipids and the stimulation of NKT cells, which are known to counteract Type 1 diabetes development. We propose that this is the acting mechanism by which treatment with alcohol reduces the incidence of diabetes in NOD mice. This is corroborated by epidemiology showing beneficial effect of alcohol to reduce the severity of atherosclerosis and related diseases.

Uhrf1 Controls iNKT Cell Survival and Differentiation through the Akt-mTOR Axis

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Yu Cui

2016-04-01

Full Text Available Uhrf1 (also known as Np95 is a regulator of DNA methylation and histone ubiquitination and plays an important role in embryogenesis and tumorigenesis. Here, we report that Uhrf1 is essential for invariant natural killer T (iNKT cell development. We found that Uhrf1 was significantly upregulated in stage 1 iNKT cells. Targeted disruption of Uhrf1 resulted in stage 1-specific transition defects as observed by not only increased apoptosis, but also aberrant effector differentiation, which eventually led to the impaired generation of iNKT cells in Uhrf1-deficient mice. Notably, Uhrf1 deficiency resulted in attenuated activation of Akt-mTOR signaling in stage 1 iNKT cells and overexpression of active Akt rescued iNKT cell developmental defects. Collectively, our results suggest that Uhrf1 regulation of the Akt-mTOR signaling pathway is required for iNKT cell development.

T cell progenitors in the mouse fetal liver

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Rabinowich, H.; Umiel, T.; Globerson, A.

1983-01-01

Fourteen-day mouse fetal liver was found to contain cells capable of giving rise to T as well as B cell functions. The experimental system consisted of congenic C3H/DiSn and (C3H/DiSn X C3H.SW)F1 lethally irradiated (900 R) mice reconstituted with C3H/DiSn fetal liver or bone marrow cells. Assays included thyroid allograft rejection as well as in vitro measurement of reactivity to phytohemagglutinin (PHA) and concanavalin A (Con A) and in a mixed lymphocyte culture (MLC) system in spleen, lymph node, and thymus cells. The fetal liver chimeras were found to become as capable as the bone marrow chimeras in responding in these various assays. The T cell responses lagged behind the responses to the B cell mitogens dextran sulfate (DXS) and lipopolysaccharide (LPS) (30 days after reconstitution, as compared with 14 days for DXS and 21 for LPS). The reacting cells were of the donor genotype, as revealed after treatment with C3H/DiSn (H-2k) anti-C3H.SW (H-2b) congenic sera. T cell responses were not manifest in thymectomized (TX) chimeras. Hence, the liver seems to contain cells capable of developing into T cell lineages in a thymus-dependent process

Cyclooxygenase-2 Inhibition Enhances Proliferation of NKT Cells Derived from Patients with Laryngeal Cancer.

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Klatka, Janusz; Grywalska, Ewelina; Hymos, Anna; Guz, Małgorzata; Polberg, Krzysztof; Roliński, Jacek; Stepulak, Andrzej

2017-08-01

The aim of this study was to analyze whether inhibition of cyclooxygenase-2 by celecoxib and the subsequent enhancement in the proliferation of natural killer T (NKT) cells could play a role in dendritic cell (DC)-based laryngeal cancer (LC) immunotherapy. Peripheral blood mononuclear cells were obtained from 48 male patients diagnosed with LC and 30 control patients without cancer disease. Neoplastic cell lysate preparations were made from cancer tissues obtained after surgery and used for in vitro DCs generation. NKT cells proliferation assay was performed based on 3 H-thymidine incorporation assay. An increased proliferation of NKT cells was obtained from control patients compared to NKT cells obtained from LC patients regardless of the type of stimulation or treatment. In the patient group diagnosed with LC, COX-2 inhibition resulted in a significantly enhanced proliferation of NKT cells when stimulated with autologous DCs than NKT cells stimulated with DCs without COX-2 inhibition. These correlations were not present in the control group. Higher proliferation rate of NKT cells was also observed in non-metastatic and highly differentiated LC, which was independent of the type of stimulation or treatment. COX-2 inhibition could be regarded as immunotherapy-enhancing tool in patients with LC. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

IL-17-producing NKT cells depend exclusively on IL-7 for homeostasis and survival.

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Webster, K E; Kim, H-O; Kyparissoudis, K; Corpuz, T M; Pinget, G V; Uldrich, A P; Brink, R; Belz, G T; Cho, J-H; Godfrey, D I; Sprent, J

2014-09-01

Natural killer T (NKT) cells are innate-like T cells that rapidly recognize pathogens and produce cytokines that shape the ensuing immune response. IL-17-producing NKT cells are enriched in barrier tissues, such as the lung, skin, and peripheral lymph nodes, and the factors that maintain this population in the periphery have not been elucidated. Here we show that NKT17 cells deviate from other NKT cells in their survival requirements. In contrast to conventional NKT cells that are maintained by IL-15, RORγt(+) NKT cells are IL-15 independent and instead rely completely on IL-7. IL-7 initiates a T-cell receptor-independent (TCR-independent) expansion of NKT17 cells, thus supporting their homeostasis. Without IL-7, survival is dramatically impaired, yet residual cells remain lineage committed with no downregulation of RORγt evident. Their preferential response to IL-7 does not reflect enhanced signaling through STAT proteins, but instead is modulated via the PI3K/AKT/mTOR signaling pathway. The ability to compete for IL-7 is dependent on high-density IL-7 receptor expression, which would promote uptake of low levels of IL-7 produced in the non-lymphoid sites of lung and skin. This dependence on IL-7 is also reported for RORγt(+) innate lymphoid cells and CD4(+) Th17 cells, and suggests common survival requirements for functionally similar cells.

Manifestation of Non-Alcoholic Fatty Liver Disease/Non-Alcoholic Steatohepatitis in Different Dietary Mouse Models

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Vera HI Fengler

2016-05-01

Full Text Available Non-alcoholic fatty liver disease (NAFLD and non-alcoholic steatohepatitis (NASH, which are usually associated with obesity and metabolic syndrome, are considerable health and economic issues due to the rapid increase of their prevalence in Western society. Histologically, the diseases are characterised by steatosis, hepatic inflammation, and if further progressed, fibrosis. Dietary-induced mouse models are widely used in investigations of the development and progression of NAFLD and NASH; these models attempt to mimic the histological and metabolic features of the human diseases. However, the majority of dietary mouse models fail to reflect the whole pathophysiological spectrum of NAFLD and NASH. Some models exhibit histological features similar to those seen in humans while lacking the metabolic context, while others resemble the metabolic conditions leading to NAFLD in humans but fail to mimic the whole histological spectrum, including progression from steatosis to liver fibrosis, and thus fail to mimic NASH. This review summarises the advantages and disadvantages of the different dietary-induced mouse models of NAFLD and NASH, with a focus on the genetic background of several commonly used wild-type mouse strains as well as gender and age, which influence the development and progression of these liver diseases.

Innate invariant NKT cells recognize Mycobacterium tuberculosis-infected macrophages, produce interferon-gamma, and kill intracellular bacteria.

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Isabel Sada-Ovalle

2008-12-01

Full Text Available Cellular immunity to Mycobacterium tuberculosis (Mtb requires a coordinated response between the innate and adaptive arms of the immune system, resulting in a type 1 cytokine response, which is associated with control of infection. The contribution of innate lymphocytes to immunity against Mtb remains controversial. We established an in vitro system to study this question. Interferon-gamma is produced when splenocytes from uninfected mice are cultured with Mtb-infected macrophages, and, under these conditions, bacterial replication is suppressed. This innate control of bacterial replication is dependent on CD1d-restricted invariant NKT (iNKT cells, and their activation requires CD1d expression by infected macrophages as well as IL-12 and IL-18. We show that iNKT cells, even in limiting quantities, are sufficient to restrict Mtb replication. To determine whether iNKT cells contribute to host defense against tuberculosis in vivo, we adoptively transferred iNKT cells into mice. Primary splenic iNKT cells obtained from uninfected mice significantly reduce the bacterial burden in the lungs of mice infected with virulent Mtb by the aerosol route. Thus, iNKT cells have a direct bactericidal effect, even in the absence of synthetic ligands such as alpha-galactosylceramide. Our finding that iNKT cells protect mice against aerosol Mtb infection is the first evidence that CD1d-restricted NKT cells mediate protection against Mtb in vivo.

The cytokine profile of human NKT cells and PBMCs is dependent on donor sex and stimulus.

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Bernin, Hannah; Fehling, Helena; Marggraff, Claudia; Tannich, Egbert; Lotter, Hannelore

2016-08-01

Sex-related variations in natural killer T (NKT) cells may influence immunoregulation and outcome of infectious and autoimmune diseases. We analyzed sex-specific differences in peripheral blood NKTs and peripheral blood mononuclear cells (PBMCs) from men and women and determined the frequencies of NKT cells and their subpopulations [CD4(+); CD8(+); double negative (DN)] and the levels of cytokine production following stimulation with the NKT cell ligands α-Galactosylceramide (αGalCer) and Entamoeba histolytica lipopeptidephosphoglycan (Lotter et al. in PLoS Pathog 5(5):e1000434, 2009). Total and DN NKT cells were more abundant in women than in men. In women, αGalCer induced higher production of intracellular IFNγ, IL-4, IL-17 and TNF by CD4(+) and DN(+)NKT cells. Both ligands induced expression of multiple cytokines in PBMCs and influenced the ratio of NKT cell subpopulations during long-term culture. Although the sex-specific differences in frequencies of NKT cells and their subpopulations were marginal, the significant sex-specific differences in cytokine production might influence disease outcomes.

Targeted induction of interferon-λ in humanized chimeric mouse liver abrogates hepatotropic virus infection.

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Nakagawa, Shin-ichiro; Hirata, Yuichi; Kameyama, Takeshi; Tokunaga, Yuko; Nishito, Yasumasa; Hirabayashi, Kazuko; Yano, Junichi; Ochiya, Takahiro; Tateno, Chise; Tanaka, Yasuhito; Mizokami, Masashi; Tsukiyama-Kohara, Kyoko; Inoue, Kazuaki; Yoshiba, Makoto; Takaoka, Akinori; Kohara, Michinori

2013-01-01

The interferon (IFN) system plays a critical role in innate antiviral response. We presume that targeted induction of IFN in human liver shows robust antiviral effects on hepatitis C virus (HCV) and hepatitis B virus (HBV). This study used chimeric mice harboring humanized livers and infected with HCV or HBV. This mouse model permitted simultaneous analysis of immune responses by human and mouse hepatocytes in the same liver and exploration of the mechanism of antiviral effect against these viruses. Targeted expression of IFN was induced by treating the animals with a complex comprising a hepatotropic cationic liposome and a synthetic double-stranded RNA analog, pIC (LIC-pIC). Viral replication, IFN gene expression, IFN protein production, and IFN antiviral activity were analyzed (for type I, II and III IFNs) in the livers and sera of these humanized chimeric mice. Following treatment with LIC-pIC, the humanized livers of chimeric mice exhibited increased expression (at the mRNA and protein level) of human IFN-λs, resulting in strong antiviral effect on HBV and HCV. Similar increases were not seen for human IFN-α or IFN-β in these animals. Strong induction of IFN-λs by LIC-pIC occurred only in human hepatocytes, and not in mouse hepatocytes nor in human cell lines derived from other (non-hepatic) tissues. LIC-pIC-induced IFN-λ production was mediated by the immune sensor adaptor molecules mitochondrial antiviral signaling protein (MAVS) and Toll/IL-1R domain-containing adaptor molecule-1 (TICAM-1), suggesting dual recognition of LIC-pIC by both sensor adaptor pathways. These findings demonstrate that the expression and function of various IFNs differ depending on the animal species and tissues under investigation. Chimeric mice harboring humanized livers demonstrate that IFN-λs play an important role in the defense against human hepatic virus infection.

Stepwise development of MAIT cells in mouse and human.

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Emmanuel Martin

2009-03-01

Full Text Available Mucosal-associated invariant T (MAIT cells display two evolutionarily conserved features: an invariant T cell receptor (TCRalpha (iTCRalpha chain and restriction by the nonpolymorphic class Ib major histocompatibility complex (MHC molecule, MHC-related molecule 1 (MR1. MR1 expression on thymus epithelial cells is not necessary for MAIT cell development but their accumulation in the gut requires MR1 expressing B cells and commensal flora. MAIT cell development is poorly known, as these cells have not been found in the thymus so far. Herein, complementary human and mouse experiments using an anti-humanValpha7.2 antibody and MAIT cell-specific iTCRalpha and TCRbeta transgenic mice in different genetic backgrounds show that MAIT cell development is a stepwise process, with an intra-thymic selection followed by peripheral expansion. Mouse MAIT cells are selected in an MR1-dependent manner both in fetal thymic organ culture and in double iTCRalpha and TCRbeta transgenic RAG knockout mice. In the latter mice, MAIT cells do not expand in the periphery unless B cells are added back by adoptive transfer, showing that B cells are not required for the initial thymic selection step but for the peripheral accumulation. In humans, contrary to natural killer T (NKT cells, MAIT cells display a naïve phenotype in the thymus as well as in cord blood where they are in low numbers. After birth, MAIT cells acquire a memory phenotype and expand dramatically, up to 1%-4% of blood T cells. Finally, in contrast with NKT cells, human MAIT cell development is independent of the molecular adaptor SAP. Interestingly, mouse MAIT cells display a naïve phenotype and do not express the ZBTB16 transcription factor, which, in contrast, is expressed by NKT cells and the memory human MAIT cells found in the periphery after birth. In conclusion, MAIT cells are selected by MR1 in the thymus on a non-B non-T hematopoietic cell, and acquire a memory phenotype and expand in the

Antigen Specificity of Type I NKT Cells Is Governed by TCR β-Chain Diversity.

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Cameron, Garth; Pellicci, Daniel G; Uldrich, Adam P; Besra, Gurdyal S; Illarionov, Petr; Williams, Spencer J; La Gruta, Nicole L; Rossjohn, Jamie; Godfrey, Dale I

2015-11-15

NKT cells recognize lipid-based Ags presented by CD1d. Type I NKT cells are often referred to as invariant owing to their mostly invariant TCR α-chain usage (Vα14-Jα18 in mice, Vα24-Jα18 in humans). However, these cells have diverse TCR β-chains, including Vβ8, Vβ7, and Vβ2 in mice and Vβ11 in humans, joined to a range of TCR Dβ and Jβ genes. In this study, we demonstrate that TCR β-chain composition can dramatically influence lipid Ag recognition in an Ag-dependent manner. Namely, the glycolipids α-glucosylceramide and isoglobotrihexosylceramide were preferentially recognized by Vβ7(+) NKT cells from mice, whereas the α-galactosylceramide analog OCH, with a truncated sphingosine chain, was preferentially recognized by Vβ8(+) NKT cells from mice. We show that the influence of the TCR β-chain is due to a combination of Vβ-, Jβ-, and CDR3β-encoded residues and that these TCRs can recapitulate the selective Ag reactivity in TCR-transduced cell lines. Similar observations were made with human NKT cells where different CDR3β-encoded residues determined Ag preference. These findings indicate that NKT TCR β-chain diversity results in differential and nonhierarchical Ag recognition by these cells, which implies that some Ags can preferentially activate type I NKT cell subsets. Copyright © 2015 by The American Association of Immunologists, Inc.

Restored Circulating Invariant NKT Cells Are Associated with Viral Control in Patients with Chronic Hepatitis B

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Jiang, Xiaotao; Zhang, Mingxia; Lai, Qintao; Huang, Xuan; Li, Yongyin; Sun, Jian; Abbott, William G.H.; Ma, Shiwu; Hou, Jinlin

2011-01-01

Invariant NKT (iNKT) cells are involved in the pathogenesis of various infectious diseases. However, their role in hepatitis B virus (HBV) infection is not fully understood, especially in human species. In this study, 35 chronic hepatitis B (CHB) patients, 25 inactive carriers (IC) and 36 healthy controls (HC) were enrolled and the proportions of circulating iNKT cells in fresh isolated peripheral blood mononuclear cells (PBMC) were detected by flow cytometry. A longitudinal analysis was also conducted in 19 CHB patients who received antiviral therapy with telbivudine. Thereafter, the immune functions of iNKT cells were evaluated by cytokine secretion and a two-chamber technique. The median frequency of circulating iNKT cells in CHB patients (0.13%) was lower than that in HC (0.24%, P = 0.01) and IC (0.19%, P = 0.02), and increased significantly during antiviral therapy with telbivudine (P = 0.0176). The expressions of CC chemokine receptor 5 (CCR5) and CCR6 were dramatically higher on iNKT cells (82.83%±9.87%, 67.67%±16.83% respectively) than on conventional T cells (30.5%±5.65%, 14.02%±5.92%, both P<0.001) in CHB patients. Furthermore, iNKT cells could migrate toward the CC chemokine ligand 5. Patients with a high ratio (≥1.0) of CD4−/CD4+ iNKT cells at baseline had a higher rate (58.33%) of HBeAg seroconversion than those with a low ratio (<1.0, 0%, P = 0.0174). In conclusion, there is a low frequency of peripheral iNKT cells in CHB patients, which increases to normal levels with viral control. The ratio of CD4−/CD4+ iNKT cells at baseline may be a useful predictor for HBeAg seroconversion in CHB patients on telbivudine therapy. PMID:22194934

2,3,7,8-TCDD enhances the sensitivity of mice to concanavalin A immune-mediated liver injury

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Fullerton, Aaron M., E-mail: fuller22@msu.edu [Department of Pharmacology and Toxicology, Center for Integrative Toxicology, Michigan State University, 1129 Farm Lane, Room 215, East Lansing, MI 48824 (United States); Roth, Robert A., E-mail: rothr@msu.edu [Department of Pharmacology and Toxicology, Center for Integrative Toxicology, Michigan State University, Food Safety and Toxicology Building, 1129 Farm Lane, Room 221, East Lansing, MI 48824 (United States); Ganey, Patricia E., E-mail: ganey@msu.edu [Department of Pharmacology and Toxicology, Center for Integrative Toxicology, Michigan State University, Food Safety and Toxicology Building, 1129 Farm Lane, Room 214, East Lansing, MI 48824 (United States)

2013-01-15

Inflammation plays a major role in immune-mediated liver injury, and exposure to environmental pollutants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to alter the inflammatory response as well as affect immune cell activity. In this study, we tested the hypothesis that TCDD pretreatment exacerbates hepatotoxicity in a murine model of immune-mediated liver injury induced by concanavalin A (Con A) administration. Mice were pretreated with 30 μg/kg TCDD or vehicle control on day zero and then given either Con A or saline intravenously on day four. Mice treated with TCDD did not develop liver injury; however, TCDD pretreatment increased liver injury resulting from moderate doses of Con A (4–10 mg/kg). TCDD-pretreated mice had altered plasma concentrations of inflammatory cytokines, including interferon gamma (IFNγ), and TCDD/Con A-induced hepatotoxicity was attenuated in IFNγ knockout mice. At various times after treatment, intrahepatic immune cells were isolated, and expression of cell activation markers as well as cytolytic proteins was determined. TCDD pretreatment increased the proportion of activated natural killer T (NKT) cells and the percent of cells expressing Fas ligand (FasL) after Con A administration. In addition FasL knockout mice and mice treated with CD18 antiserum were both protected from TCDD/Con A-induced hepatotoxicity, suggesting a requirement for direct cell–cell interaction between effector immune cells and parenchymal cell targets in the development of liver injury from TCDD/Con A treatment. In summary, exposure to TCDD increased NKT cell activation and exacerbated immune-mediated liver injury induced by Con A through a mechanism involving IFNγ and FasL expression. -- Highlights: ► TCDD pretreatment sensitizes mice to Con A-induced hepatotoxicity. ► TCDD pretreatment increased concentration of IFNγ in plasma after Con A. ► Con A-induced activation of NKT cells was increased by TCDD pretreatment. ► Fas

2,3,7,8-TCDD enhances the sensitivity of mice to concanavalin A immune-mediated liver injury

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Fullerton, Aaron M.; Roth, Robert A.; Ganey, Patricia E.

2013-01-01

Inflammation plays a major role in immune-mediated liver injury, and exposure to environmental pollutants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to alter the inflammatory response as well as affect immune cell activity. In this study, we tested the hypothesis that TCDD pretreatment exacerbates hepatotoxicity in a murine model of immune-mediated liver injury induced by concanavalin A (Con A) administration. Mice were pretreated with 30 μg/kg TCDD or vehicle control on day zero and then given either Con A or saline intravenously on day four. Mice treated with TCDD did not develop liver injury; however, TCDD pretreatment increased liver injury resulting from moderate doses of Con A (4–10 mg/kg). TCDD-pretreated mice had altered plasma concentrations of inflammatory cytokines, including interferon gamma (IFNγ), and TCDD/Con A-induced hepatotoxicity was attenuated in IFNγ knockout mice. At various times after treatment, intrahepatic immune cells were isolated, and expression of cell activation markers as well as cytolytic proteins was determined. TCDD pretreatment increased the proportion of activated natural killer T (NKT) cells and the percent of cells expressing Fas ligand (FasL) after Con A administration. In addition FasL knockout mice and mice treated with CD18 antiserum were both protected from TCDD/Con A-induced hepatotoxicity, suggesting a requirement for direct cell–cell interaction between effector immune cells and parenchymal cell targets in the development of liver injury from TCDD/Con A treatment. In summary, exposure to TCDD increased NKT cell activation and exacerbated immune-mediated liver injury induced by Con A through a mechanism involving IFNγ and FasL expression. -- Highlights: ► TCDD pretreatment sensitizes mice to Con A-induced hepatotoxicity. ► TCDD pretreatment increased concentration of IFNγ in plasma after Con A. ► Con A-induced activation of NKT cells was increased by TCDD pretreatment. ► Fas

A possible role for NKT-like cells in patients with chronic hepatitis B during telbivudine treatment.

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Diao, Hongyan; He, Jianqin; Zheng, Qishi; Chen, Jianing; Cui, Guangying; Wei, Yingfeng; Ye, Ping; Kohanawa, Masashi; Li, Lanjuan

2014-07-01

Natural killer T-like (NKT-like) cells are a source of different pro-inflammatory cytokines and therefore may be involved in inflammatory processes. However, little is known about NKT-like cells during antiviral therapy. In this study, we observed significantly higher numbers of CD3(+)CD56(+) cells in patients with chronic hepatitis B (CHB) than healthy controls. Importantly, CD3(+)CD56(+) NKT-like cells markedly decreased during telbivudine treatment in patients with CHB, and a positive correlation between NKT-like cell frequency and the serum HBV DNA level was observed during early antiviral therapy. Interestingly, NKT-like cell frequency significantly reduced in well-responders at week 12 of telbivudine therapy compared to baseline, but did not significantly change in non-responders after treatment. Previous studies have shown that interleukin (IL)-17 plays a role in the pathogenesis of CHB. Serum IL-17 levels reduced significantly during early antiviral therapy, however, interferon (IFN)-γ, IL-6 and tumor necrosis factor (TNF)-α levels did not change significantly. A positive correlation was observed between the NKT-like cell frequency and serum IL-17 level in CHB patients, and NKT-like cells isolated from patients with CHB secreted substantial amounts of IL-17 in vitro. These results suggest that the NKT-like cell frequency may be one of useful immunologic marker for evaluating the efficacy of anti-HBV therapy, and that NKT-like cells are also an important source of IL-17 (in addition to conventional T cells) in patients with CHB. Copyright © 2014 Elsevier B.V. All rights reserved.

Functional Invariant NKT Cells in Pig Lungs Regulate the Airway Hyperreactivity: A Potential Animal Model

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Manickam, Cordelia; Khatri, Mahesh; Rauf, Abdul; Li, Xiangming; Tsuji, Moriya; Rajashekara, Gireesh; Dwivedi, Varun

2015-01-01

Important roles played by invariant natural killer T (iNKT) cells in asthma pathogenesis have been demonstrated. We identified functional iNKT cells and CD1d molecules in pig lungs. Pig iNKT cells cultured in the presence of α-GalCer proliferated and secreted Th1 and Th2 cytokines. Like in other animal models, direct activation of pig lung iNKT cells using α-GalCer resulted in acute airway hyperreactivity (AHR). Clinically, acute AHR-induced pigs had increased respiratory rate, enhanced mucus secretion in the airways, fever, etc. In addition, we observed petechial hemorrhages, infiltration of CD4+ cells, and increased Th2 cytokines in AHR-induced pig lungs. Ex vivo proliferated iNKT cells of asthma induced pigs in the presence of C-glycoside analogs of α-GalCer had predominant Th2 phenotype and secreted more of Th2 cytokine, IL-4. Thus, baby pigs may serve as a useful animal model to study iNKT cell-mediated AHR caused by various environmental and microbial CD1d-specific glycolipid antigens. PMID:21042929

Pak2 Controls Acquisition of NKT Cell Fate by Regulating Expression of the Transcription Factors PLZF and Egr2

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O’Hagan, Kyle L.; Zhao, Jie; Pryshchep, Olga; Wang, Chyung-Ru

2015-01-01

NKT cells constitute a small population of T cells developed in the thymus that produce large amounts of cytokines and chemokines in response to lipid Ags. Signaling through the Vα14-Jα18 TCR instructs commitment to the NKT cell lineage, but the precise signaling mechanisms that instruct their lineage choice are unclear. In this article, we report that the cytoskeletal remodeling protein, p21-activated kinase 2 (Pak2), was essential for NKT cell development. Loss of Pak2 in T cells reduced stage III NKT cells in the thymus and periphery. Among different NKT cell subsets, Pak2 was necessary for the generation and function of NKT1 and NKT2 cells, but not NKT17 cells. Mechanistically, expression of Egr2 and promyelocytic leukemia zinc finger (PLZF), two key transcription factors for acquiring the NKT cell fate, were markedly diminished in the absence of Pak2. Diminished expression of Egr2 and PLZF were not caused by aberrant TCR signaling, as determined using a Nur77-GFP reporter, but were likely due to impaired induction and maintenance of signaling lymphocyte activation molecule 6 expression, a TCR costimulatory receptor required for NKT cell development. These data suggest that Pak2 controls thymic NKT cell development by providing a signal that links Egr2 to induce PLZF, in part by regulating signaling lymphocyte activation molecule 6 expression. PMID:26519537

iNKT Cell Emigration out of the Lung Vasculature Requires Neutrophils and Monocyte-Derived Dendritic Cells in Inflammation

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Ajitha Thanabalasuriar

2016-09-01

Full Text Available iNKT cells are a subset of innate T cells that recognize glycolipids presented on CD1d molecules and protect against bacterial infections, including S. pneumoniae. Using lung intravital imaging, we examined the behavior and mechanism of pulmonary iNKT cell activation in response to the specific iNKT cell ligand α-galactosylceramide or S. pneumoniae infection. In untreated mice, the major fraction of iNKT cells resided in the vasculature, but a small critical population resided in the extravascular space in proximity to monocyte-derived DCs. Administration of either α-GalCer or S. pneumoniae induced CD1d-dependent rapid recruitment of neutrophils out of the vasculature. The neutrophils guided iNKT cells from the lung vasculature via CCL17. Depletion of monocyte-derived DCs abrogated both the neutrophil and subsequent iNKT cell extravasation. Moreover, impairing iNKT cell recruitment by blocking CCL17 increased susceptibility to S. pneumoniae infection, suggesting a critical role for the influx of iNKT cells in host defense.

Percentages of NKT cells in the tissues of patients with non-small cell lung cancer who underwent surgical treatment.

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Pyszniak, Maria; Rybojad, Paweł; Pogoda, Katarzyna; Jabłonka, Andrzej; Bojarska-Junak, Agnieszka; Tabarkiewicz, Jacek

2014-03-01

Natural killer T (NKT) cells are involved in the antitumor response by direct cytotoxicity and indirectly through activation of effector cells. Recent studies have shown a relationship between the number and function of NKT cells and clinical outcomes. NKT cells seem to represent a promising tool for immunotherapy of cancer. The aim of the study was to evaluate the distribution of NKT cells in peripheral blood, lymph nodes and tumor tissue of non-small cell lung cancer (NSCLC) patients, as well as development of the most efficient set of cytokines stimulating differentiation of NKT cells. We evaluated the percentage of iNKT+CD3+ cells in the tissues collected from patients with NSCLC. For the generation of NKT cells, we cultured cells isolated from the blood of 20 healthy donors and from the tissues of 4 NSCLC patients. Cells were stimulated with α-GalCer in combinations with cytokines. We noted significant differences in the percentages of NKT cells in the patients' tissues. The highest percentage of these cells was observed in the tumor tissue and the lowest in the lymph nodes. In vitro, in healthy donors all α-GalCer-cytokine combinations were effective in stimulation of NKT cells' proliferation. NKT cells' proliferation was the most efficiently stimulated by α-GalCer+IL-2+IL-7 and α-GalCer+IL-2+IFN-γ. Our results suggest that in the course of NSCLC, NKT cells migrate to the primary tumor and accumulate therein. All tested combinations of α-GalCer and cytokines were capable of generation of NKT cells in vitro.

Lactic acid in tumor microenvironments causes dysfunction of NKT cells by interfering with mTOR signaling.

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Xie, Di; Zhu, Shasha; Bai, Li

2016-12-01

Cellular metabolism has been shown to regulate differentiation and function of immune cells. Tumor associated immune cells undergo phenotypic and functional alterations due to the change of cellular metabolism in tumor microenvironments. NKT cells are good candidates for immunotherapies against tumors and have been used in several clinical trials. However, the influences of tumor microenvironments on NKT cell functions remain unclear. In our studies, lactic acid in tumor microenvironments inhibited IFNγ and IL4 productions from NKT cells, and more profound influence on IFNγ was observed. By adjusting the pH of culture medium we further showed that, dysfunction of NKT cells could simply be induced by low extracellular pH. Moreover, low extracellular pH inhibited NKT cell functions by inhibiting mammalian target of rapamycin (mTOR) signaling and nuclear translocation of promyelocytic leukemia zinc-finger (PLZF). Together, our results suggest that tumor acidic microenvironments could interfere with NKT cell functions through metabolic controls.

Skewed distribution of circulating activated natural killer T (NKT) cells in patients with common variable immunodeficiency disorders (CVID).

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Carvalho, Karina I; Melo, Karina M; Bruno, Fernanda R; Snyder-Cappione, Jennifer E; Nixon, Douglas F; Costa-Carvalho, Beatriz T; Kallas, Esper G

2010-09-09

Common variable immunodeficiency disorder (CVID) is the commonest cause of primary antibody failure in adults and children, and characterized clinically by recurrent bacterial infections and autoimmune manifestations. Several innate immune defects have been described in CVID, but no study has yet investigated the frequency, phenotype or function of the key regulatory cell population, natural killer T (NKT) cells. We measured the frequencies and subsets of NKT cells in patients with CVID and compared these to healthy controls. Our results show a skewing of NKT cell subsets, with CD4+ NKT cells at higher frequencies, and CD8+ NKT cells at lower frequencies. However, these cells were highly activated and expression CD161. The NKT cells had a higher expression of CCR5 and concomitantly expression of CCR5+CD69+CXCR6 suggesting a compensation of the remaining population of NKT cells for rapid effector action.

NK and NKT-Like Cells in Patients with Recurrent Furunculosis.

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Nowicka, Danuta; Grywalska, Ewelina; Fitas, Elżbieta; Mielnik, Michał; Roliński, Jacek

2017-12-13

To analyze changes in the number and percentage of NK and NKT-like cells in relation to other immune cells as well as to examine associations between increased susceptibility to infections and NK and NKT-like status in patients with recurrent furunculosis (RF) and healthy controls. Thirty patients with RF and 20 healthy age- and sex-matched volunteers were recruited. Blood samples were examined. Lymphocyte count and cytometric analyses were conducted. For statistical analysis, the Student's t test, F test, and Brown-Forsythe test were used for comparison between groups of variables. Associations were assessed with Pearson coefficient. Patients with RF had lower lymphocyte count than controls. Additionally, they presented with the following changes in the blood picture: a significant increase in the number of NK cells with a CD3 + CD16 + CD56 + phenotype; a proportional increase in the number and percentage of NKT-like cells with a CD3 + CD16 + CD56 + phenotype; a significant decrease in the number and percentage of T CD3 + cells. The number of NK cells was strongly positively correlated with the number of CD3 cells (r = 0.6162). The number of NKT cells was strongly positively correlated with CD3 cells (r = 0.6885) and CD3CD8 cells (r = 0.5465). Periodic exacerbations in RF are associated with the development of furuncles, which are a result of many already discovered as well as just being examined mechanisms. One of them is a significant increase in the number and most likely activation of NK and NKT-like cells during the formation of the inflammatory process and furuncles.

TCRα-TCRβ pairing controls recognition of CD1d and directs the development of adipose NKT cells.

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Vieth, Joshua A; Das, Joy; Ranaivoson, Fanomezana M; Comoletti, Davide; Denzin, Lisa K; Sant'Angelo, Derek B

2017-01-01

The interaction between the T cell antigen receptor (TCR) expressed by natural killer T cells (NKT cells) and the antigen-presenting molecule CD1d is distinct from interactions between the TCR and major histocompatibility complex (MHC). Our molecular modeling suggested that a hydrophobic patch created after TCRα-TCRβ pairing has a role in maintaining the conformation of the NKT cell TCR. Disruption of this patch ablated recognition of CD1d by the NKT cell TCR but not interactions of the TCR with MHC. Partial disruption of the patch, while permissive to the recognition of CD1d, significantly altered NKT cell development, which resulted in the selective accumulation of adipose-tissue-resident NKT cells. These results indicate that a key component of the TCR is essential for the development of a distinct population of NKT cells.

iNKT cells suppress the CD8+ T cell response to a murine Burkitt's-like B cell lymphoma.

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Ryan L Bjordahl

Full Text Available The T cell response to B cell lymphomas differs from the majority of solid tumors in that the malignant cells themselves are derived from B lymphocytes, key players in immune response. B cell lymphomas are therefore well situated to manipulate their surrounding microenvironment to enhance tumor growth and minimize anti-tumor T cell responses. We analyzed the effect of T cells on the growth of a transplantable B cell lymphoma and found that iNKT cells suppressed the anti-tumor CD8(+ T cell response. Lymphoma cells transplanted into syngeneic wild type (WT mice or Jalpha18(-/- mice that specifically lack iNKT cells grew initially at the same rate, but only the mice lacking iNKT cells were able to reject the lymphoma. This effect was due to the enhanced activity of tumor-specific CD8(+ T cells in the absence of iNKT cells, and could be partially reversed by reconstitution of iNKT cells in Jalpha 18(-/- mice. Treatment of tumor-bearing WT mice with alpha -galactosyl ceramide, an activating ligand for iNKT cells, reduced the number of tumor-specific CD8(+ T cells. In contrast, lymphoma growth in CD1d1(-/- mice that lack both iNKT and type II NKT cells was similar to that in WT mice, suggesting that type II NKT cells are required for full activation of the anti-tumor immune response. This study reveals a tumor-promoting role for iNKT cells and suggests their capacity to inhibit the CD8(+ T cell response to B cell lymphoma by opposing the effects of type II NKT cells.

Pak2 Controls Acquisition of NKT Cell Fate by Regulating Expression of the Transcription Factors PLZF and Egr2.

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O'Hagan, Kyle L; Zhao, Jie; Pryshchep, Olga; Wang, Chyung-Ru; Phee, Hyewon

2015-12-01

NKT cells constitute a small population of T cells developed in the thymus that produce large amounts of cytokines and chemokines in response to lipid Ags. Signaling through the Vα14-Jα18 TCR instructs commitment to the NKT cell lineage, but the precise signaling mechanisms that instruct their lineage choice are unclear. In this article, we report that the cytoskeletal remodeling protein, p21-activated kinase 2 (Pak2), was essential for NKT cell development. Loss of Pak2 in T cells reduced stage III NKT cells in the thymus and periphery. Among different NKT cell subsets, Pak2 was necessary for the generation and function of NKT1 and NKT2 cells, but not NKT17 cells. Mechanistically, expression of Egr2 and promyelocytic leukemia zinc finger (PLZF), two key transcription factors for acquiring the NKT cell fate, were markedly diminished in the absence of Pak2. Diminished expression of Egr2 and PLZF were not caused by aberrant TCR signaling, as determined using a Nur77-GFP reporter, but were likely due to impaired induction and maintenance of signaling lymphocyte activation molecule 6 expression, a TCR costimulatory receptor required for NKT cell development. These data suggest that Pak2 controls thymic NKT cell development by providing a signal that links Egr2 to induce PLZF, in part by regulating signaling lymphocyte activation molecule 6 expression. Copyright © 2015 by The American Association of Immunologists, Inc.

Differences in both glycosylation and binding properties between rat and mouse liver prolactin receptors.

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Lascols, O; Cherqui, G; Munier, A; Picard, J; Capeau, J

1994-05-01

To investigate whether glycanic chains of prolactin receptors (PRL-R) play a role in hormone binding activity, comparison was made of rat and mouse liver solubilized receptors with respect to both their affinity for the hormone and their glycosylation properties. As compared with rat receptors, mouse receptors exhibited a 2-fold higher affinity for human growth hormone (hGH), the hormone being bound by both tissues with a lactogenic specificity. Along with this increased affinity, mouse receptors had a 2 lower M(r) relative to rat receptors (62 kDa versus 64 kDa as measured on hGH cross-linked receptors). These differences could be ascribed to different glycosylation properties of the receptors from the two species, as supported by the followings. 1) After treatment with endoglycosidase F (endo F), rat and mouse PRL-R no longer exhibited any difference in their M(r) (54 kDa for both cross-linked receptors). 2) Neuraminidase treatment increased by 37% the binding of hGH to mouse receptors, but was ineffective on the hormone-binding to rat receptors. Conversely, wheat germ agglutinin (WGA), another sialic acid specific probe, decreased hGH binding to rat receptors by 25%, but had no effect on this process for mouse ones. 3) Marked differences were observed in the recoveries of rat and mouse hormone-receptor (HR) complexes from ricin-1- (RCA1-), concanavalin A- (ConA-) and WGA-immobilized lectins. These differences were reduced (RCA1 and ConA) or abolished (WGA) after rat and mouse receptor desialylation by neuraminidase, a treatment which decreased the M(r) of both receptors by 2 kDa. Taken together, these results strongly suggest that the PRL-R from rat and mouse liver contain biantennary N-linked oligosaccharidic chains with distinct type of sialylation, which may account for their differential hormone-binding affinities.

Reconfiguration of NKT Cell Subset Compartment Is Associated with Plaque Development in Patients with Carotid Artery Stenosis.

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Cai, Lun; Yu, Lei; Liu, Sa; Li, Tongxun; Zhang, Xiaoping; Cui, Wei; Du, Jie; Zhang, Qinyi

2017-02-01

Accumulating evidence shows that immune cells play an important role in carotid atherosclerotic plaque development. In this study, we assessed the association of 6 different natural killer T (NKT) cell subsets, based on CD57 and CD8 expression, with risk for development of carotid atherosclerotic plaque (CAP). Molecular expression by peripheral NKT cells was evaluated in 13 patients with high-risk CAP and control without carotid stenosis (n = 18). High-risk CAP patients, compared with healthy subjects, had less percentage of CD57+CD8- NKT cell subsets (8.64 ± 10.15 versus 19.62 ± 10.8 %; P = 0.01) and CD57+CD8int NKT cell subsets (4.32 ± 3.04 versus 11.87 ± 8.56 %; P = 0.002), with a corresponding increase in the CD57-CD8high NKT cell subsets (33.22 ± 11.87 versus 18.66 ± 13.68 %; P = 0.007). Intracellular cytokine staining showed that CD8+ NKT cell subset was the main cytokine-producing NKT cell. Cytokine production in plasma was measured with Bio-Plex assay. The expression levels of pro-inflammatory mediators (IFN-γ, IL-17, IP-10) were significantly higher in CAP patients as compared to that from controls. These data provide evidence that NKT cell subset compartment reconfiguration in patients with carotid stenosis seems to be associated with the occurrence of carotid atherosclerotic plaque and suggest that both pathogenic and protective NKT cell subsets exist.

Activated iNKT cells promote memory CD8+ T cell differentiation during viral infection.

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Emma C Reilly

Full Text Available α-Galactosylceramide (α-GalCer is the prototypical lipid ligand for invariant NKT cells. Recent studies have proposed that α-GalCer is an effective adjuvant in vaccination against a range of immune challenges, however its mechanism of action has not been completely elucidated. A variety of delivery methods have been examined including pulsing dendritic cells with α-GalCer to optimize the potential of α-GalCer. These methods are currently being used in a variety of clinical trials in patients with advanced cancer but cannot be used in the context of vaccine development against pathogens due to their complexity. Using a simple delivery method, we evaluated α-GalCer adjuvant properties, using the mouse model for cytomegalovirus (MCMV. We measured several key parameters of the immune response to MCMV, including inflammation, effector, and central memory CD8(+ T cell responses. We found that α-GalCer injection at the time of the infection decreases viral titers, alters the kinetics of the inflammatory response, and promotes both increased frequencies and numbers of virus-specific memory CD8(+ T cells. Overall, our data suggest that iNKT cell activation by α-GalCer promotes the development of long-term protective immunity through increased fitness of central memory CD8(+ T cells, as a consequence of reduced inflammation.

Targeted induction of interferon-λ in humanized chimeric mouse liver abrogates hepatotropic virus infection.

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Shin-ichiro Nakagawa

Full Text Available BACKGROUND & AIMS: The interferon (IFN system plays a critical role in innate antiviral response. We presume that targeted induction of IFN in human liver shows robust antiviral effects on hepatitis C virus (HCV and hepatitis B virus (HBV. METHODS: This study used chimeric mice harboring humanized livers and infected with HCV or HBV. This mouse model permitted simultaneous analysis of immune responses by human and mouse hepatocytes in the same liver and exploration of the mechanism of antiviral effect against these viruses. Targeted expression of IFN was induced by treating the animals with a complex comprising a hepatotropic cationic liposome and a synthetic double-stranded RNA analog, pIC (LIC-pIC. Viral replication, IFN gene expression, IFN protein production, and IFN antiviral activity were analyzed (for type I, II and III IFNs in the livers and sera of these humanized chimeric mice. RESULTS: Following treatment with LIC-pIC, the humanized livers of chimeric mice exhibited increased expression (at the mRNA and protein level of human IFN-λs, resulting in strong antiviral effect on HBV and HCV. Similar increases were not seen for human IFN-α or IFN-β in these animals. Strong induction of IFN-λs by LIC-pIC occurred only in human hepatocytes, and not in mouse hepatocytes nor in human cell lines derived from other (non-hepatic tissues. LIC-pIC-induced IFN-λ production was mediated by the immune sensor adaptor molecules mitochondrial antiviral signaling protein (MAVS and Toll/IL-1R domain-containing adaptor molecule-1 (TICAM-1, suggesting dual recognition of LIC-pIC by both sensor adaptor pathways. CONCLUSIONS: These findings demonstrate that the expression and function of various IFNs differ depending on the animal species and tissues under investigation. Chimeric mice harboring humanized livers demonstrate that IFN-λs play an important role in the defense against human hepatic virus infection.

Type II Natural Killer T (NKT) Cells And Their Emerging Role In Health And Disease

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Dhodapkar, Madhav V.; Kumar, Vipin

2016-01-01

Natural killer T (NKT) cells recognize lipid antigens presented by a class I MHC-like molecule CD1d, a member of the CD1 family. While most of the initial studies on NKT cells focused on a subset with semi-invariant T cell receptor (TCR) termed iNKT cells, majority of CD1d-restricted lipid-reactive human T cells express diverse TCRs and are termed as type II NKT cells. These cells constitute a distinct population of circulating and tissue-resident effector T cells with immune-regulatory properties. They react to a growing list of self- as well as non-self lipid ligands, and share some properties with both iNKT as well as conventional T cells. Emerging body of evidence points to their role in the regulation of immunity to pathogens/tumors and in autoimmune/metabolic disorders. Improved understanding of the biology of these cells and the ability to manipulate their function may be of therapeutic benefit in diverse disease conditions. PMID:28115591

NKT Cells in the Induced Sputum of Severe Asthmatics

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2006-01-01

Full Text Available To determine whether there was a specific inflammatory process in severe asthmatics, the phenotypic characteristics of induced sputum immune cells were analysed among patients with severe asthma. Twenty-two induced sputa (10 severe asthmatics were studied. Flow cytometric analysis was performed using immune cells of the sputum and monoclonal antibodies to CD3, CD4, CD8, CD56, CD25, and TCRγδ . The number of NKT (CD3 + CD 56+ cells was significantly higher in the sputum of severe asthmatics compared with mild asthmatic and healthy control groups ( p<.05 . CD8+CD 56+ cells were the predominant subtype of the increased NKT cells in severe asthmatics. CD3 +CD56+Vα24 +, TCRγδ CD56+, and CD4+CD25+ T cells were significantly increased in severe asthmatic patients. These results suggest that the immunopathogenesis of severe asthmatics vary between severe and mild asthmatics, and that CD8+ CD 56+ NKT cells may play an important role in the immunopathogenesis of severe asthma.

NKT cell self-reactivity: evolutionary master key of immune homeostasis?

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Issazadeh-Navikas, Shohreh

2012-04-01

Complex immune responses have evolved to protect multicellular organisms against the invasion of pathogens. This has exerted strong developmental pressure for specialized functions that can also limit damage to self-tissue. Two arms of immunity, the innate and adaptive immune systems, have evolved for quick, non-specific immune responses to pathogens and more efficient, long-lasting ones upon specific recognition of recurrent pathogens. Specialized cells have arisen as the sentinels of these functions, including macrophages, natural killer (NK), and T and B-lymphocytes. Interestingly, a population of immune cells that can exert both of these complex functions, NKT cells, not only share common functions but also exhibit shared cell surface markers of cells of both arms of the immune system. These features, in combination with sophisticated maintenance of immune homeostasis, will be discussed. The recent finding of self-peptide reactivity of NKT cells in the context of CD1d, with capacity to regulate multiple autoimmune and inflammatory conditions, motivates the current proposal that self-reactive NKT cells might be the ancestral link between present NK and T cells. Their parallel selection through evolution by higher vertebrates could be related to their central function as master regulators of immune homeostasis that in part is shared with regulatory T cells. Hypothetical views on how self-reactive NKT cells secure such a central role will also be proposed.

Comparative Analysis of the Relationship between Trichloroethylene Metabolism and Tissue-Specific Toxicity among Inbred Mouse Strains: Liver Effects

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Yoo, Hong Sik; Bradford, Blair U.; Kosyk, Oksana; Shymonyak, Svitlana; Uehara, Takeki; Collins, Leonard B.; Bodnar, Wanda M.; Ball, Louise M.; Gold, Avram; Rusyn, Ivan

2014-01-01

Trichloroethylene (TCE) is a widely used organic solvent. Although TCE is classified as carcinogenic to humans, substantial gaps remain in our understanding of inter-individual variability in TCE metabolism and toxicity, especially in the liver. We tested a hypothesis that amounts of oxidative metabolites of TCE in mouse liver are associated with liver-specific toxicity. Oral dosing with TCE was conducted in sub-acute (600 mg/kg/d; 5 days; 7 inbred mouse strains) and sub-chronic (100 or 400 mg/kg/d; 1, 2, or 4 weeks; 2 inbred mouse strains) designs. We evaluated the quantitative relationship between strain-, dose-, and time-dependent formation of TCE metabolites from cytochrome P450-mediated oxidation [trichloroacetic acid (TCA), dichloroacetic acid (DCA), and trichloroethanol] and glutathione conjugation [S-(1,2-dichlorovinyl)-L-cysteine and S-(1,2-dichlorovinyl)glutathione] in serum and liver, and various liver toxicity phenotypes. In sub-acute study, inter-strain variability in TCE metabolite amounts was observed in serum and liver. No induction of Cyp2e1 protein levels in liver was detected. Serum and liver levels of TCA and DCA were correlated with increased transcription of peroxisome proliferator-marker genes Cyp4a10 and Acox1, but not with degree of induction in hepatocellular proliferation. In sub-chronic study, serum and liver levels of oxidative metabolites gradually decreased over time despite continuous dosing. Liver protein levels of Cyp2e1, Adh and Aldh2 were unaffected by treatment with TCE. While the magnitude of induction of peroxisome proliferator-marker genes also declined, hepatocellular proliferation increased. This study offers a unique opportunity to provide a scientific data-driven rationale for some of the major assumptions in human health assessment of TCE. PMID:25424544

Altered phenotypic and functional characteristics of CD3+CD56+ NKT-like cells in human gastric cancer.

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Peng, Liu-Sheng; Mao, Fang-Yuan; Zhao, Yong-Liang; Wang, Ting-Ting; Chen, Na; Zhang, Jin-Yu; Cheng, Ping; Li, Wen-Hua; Lv, Yi-Pin; Teng, Yong-Sheng; Guo, Gang; Luo, Ping; Chen, Weisan; Zou, Quan-Ming; Zhuang, Yuan

2016-08-23

CD3+CD56+ natural killer T (NKT)-like cells are a group of CD3+ T cells sharing characteristics of NK and T cells and constitute a major component of host anti-tumor immune response in human cancer. However, the nature, function and clinical relevance of CD3+CD56+ NKT-like cells in human gastric cancer (GC) remain unclear. In this study, we showed that the frequencies of CD3+CD56+NKT-like cells in GC tumors were significantly decreased and low levels of tumor-infiltrating CD3+CD56+ NKT-like cells were positively correlated with poor survival and disease progression. Most CD3+CD56+NKT-like cells in GC tumors were CD45RA-CD27+/- central/effector-memory cells with decreased activity and lower expression levels of CD69, NKG2D and DNAM-1 than those in non-tumor tissues. We further observed that tumor-infiltrating CD3+CD56+ NKT-like cells had impaired effector function as shown by decreased IFN-γ, TNF-α, granzyme B and Ki-67 expression. Moreover, in vitro studies showed that soluble factors released from GC tumors could induce the functional impairment of CD3+CD56+ NKT-like cells. Collectively, our data indicate that decreased tumor-infiltrating CD3+CD56+ NKT-like cells with impaired effector function are associated with tumor progression and poor survival of GC patients, which may contribute to immune escape of GC.

Does an NKT-cell-based immunotherapeutic approach have a future in multiple myeloma?

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Favreau, Mérédis; Vanderkerken, Karin

2016-01-01

Natural killer T (NKT) cells constitute a unique subset of innate-like T lymphocytes which differ from conventional T cells by recognizing lipid antigens presented by the non-polymorphic major histocompatibility complex (MHC) I-like molecule CD1d. Despite being a relatively infrequent population of lymphocytes, NKT cells can respond rapidly upon activation with glycosphingolipids by production of cytokines which aim to polarize different axes of the immune system. Due to their dual effector capacities, NKT cells can play a vital role in cancer immunity, infection, inflammation and autoimmune diseases. It is believed that modulation of their activity towards immune activation can be a useful tool in anti-tumor immunotherapeutic strategies. Here we summarize the characteristics of NKT cells and discuss their involvement in immunosurveillance. Furthermore, an update is given about their role and the progress that has been made in the field of multiple myeloma (MM). Finally, some challenges are discussed that are currently hampering further progress. PMID:26895468

NKT cells mediate the recruitment of neutrophils by stimulating epithelial chemokine secretion during colitis.

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Huang, Enyu; Liu, Ronghua; Lu, Zhou; Liu, Jiajing; Liu, Xiaoming; Zhang, Dan; Chu, Yiwei

2016-05-27

Ulcerative colitis (UC) is a kind of inflammatory bowel diseases characterized by chronic inflammation and ulcer in colon, and UC patients have increased risk of getting colorectal cancer. NKT cells are cells that express both NK cell markers and semi-invariant CD1d-restricted TCRs, can regulate immune responses via secreting a variety of cytokines upon activation. In our research, we found that the NKT cell-deficient CD1d(-/-) mice had relieved colitis in the DSS-induced colitis model. Further investigations revealed that the colon of CD1d(-/-) mice expressed less neutrophil-attracting chemokine CXCL 1, 2 and 3, and had decreased neutrophil infiltration. Infiltrated neutrophils also produced less reactive oxygen species (ROS) and TNF-α, indicating they may cause less epithelial damage. In addition, colitis-associated colorectal cancer was also relieved in CD1d(-/-) mice. During colitis, NKT cells strongly expressed TNF-α, which could stimulate CXCL 1, 2, 3 expressions by the epithelium. In conclusion, NKT cells can regulate colitis via the NKT cell-epithelium-neutrophil axis. Targeting this mechanism may help to improve the therapy of UC and prevent colitis-associated colorectal cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Type I NKT-cell-mediated TNF-α is a positive regulator of NLRP3 inflammasome priming.

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Chow, Melvyn T; Duret, Helene; Andrews, Daniel M; Faveeuw, Christelle; Möller, Andreas; Smyth, Mark J; Paget, Christophe

2014-07-01

The NLRP3 inflammasome plays a crucial role in the innate immune response to pathogens and exogenous or endogenous danger signals. Its activity must be precisely and tightly regulated to generate tailored immune responses. However, the immune cell subsets and cytokines controlling NLRP3 inflammasome activity are still poorly understood. Here, we have shown a link between NKT-cell-mediated TNF-α and NLRP3 inflammasome activity. The NLRP3 inflammasome in APCs was critical to potentiate NKT-cell-mediated immune responses, since C57BL/6 NLRP3 inflammasome-deficient mice exhibited reduced responsiveness to α-galactosylceramide. Importantly, NKT cells were found to act as regulators of NLRP3 inflammasome signaling, as NKT-cell-derived TNF-α was required for optimal IL-1β and IL-18 production by myeloid cells in response to α-galactosylceramide, by acting on the NLRP3 inflammasome priming step. Thus, NKT cells play a role in the positive regulation of NLRP3 inflammasome priming by mediating the production of TNF-α, thus demonstrating another means by which NKT cells control early inflammation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Leishmania infantum Exoproducts Inhibit Human Invariant NKT Cell Expansion and Activation

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Renata Belo

2017-06-01

Full Text Available Leishmania infantum is one of the major parasite species associated with visceral leishmaniasis, a severe form of the disease that can become lethal if untreated. This obligate intracellular parasite has developed diverse strategies to escape the host immune response, such as exoproducts (Exo carrying a wide range of molecules, including parasite virulence factors, which are potentially implicated in early stages of infection. Herein, we report that L. infantum Exo and its two fractions composed of extracellular vesicles (EVs and vesicle-depleted-exoproducts (VDEs inhibit human peripheral blood invariant natural killer T (iNKT cell expansion in response to their specific ligand, the glycolipid α-GalactosylCeramide (α-GalCer, as well as their capacity to promptly produce IL-4 and IFNγ. Using plate-bound CD1d and α-GalCer, we found that Exo, EV, and VDE fractions reduced iNKT cell activation in a dose-dependent manner, suggesting that they prevented α-GalCer presentation by CD1d molecules. This direct effect on CD1d was confirmed by the observation that CD1d:α-GalCer complex formation was impaired in the presence of Exo, EV, and VDE fractions. Furthermore, lipid extracts from the three compounds mimicked the inhibition of iNKT cell activation. These lipid components of L. infantum exoproducts, including EV and VDE fractions, might compete for CD1-binding sites, thus blocking iNKT cell activation. Overall, our results provide evidence for a novel strategy through which L. infantum can evade immune responses of mammalian host cells by preventing iNKT lymphocytes from recognizing glycolipids in a TCR-dependent manner.

In vitro metabolism studies of 18F-labeled 1-phenylpiperazine using mouse liver S9 fraction

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Ryu, Eun Kyoung; Choe, Yearn Seong; Kim, Dong Hyun; Ko, Bong-Ho; Choi, Yong; Lee, Kyung-Han; Kim, Byung-Tae

2006-01-01

The in vitro metabolism of 1-(4-[ 18 F]fluoromethylbenzyl)-4-phenylpiperazine ([ 18 F]1) and 1-(4-[ 18 F]fluorobenzyl)-4-phenylpiperazine ([ 18 F]2) was investigated using mouse liver S9 fraction. Results were compared to those of in vivo metabolism using mouse blood and bone and to in vitro metabolism using mouse liver microsomes. Defluorination was the main metabolic pathway for [ 18 F]1 in vitro and in vivo. Based on TLC, HPLC and LC-MS data, [ 18 F]fluoride ion and less polar radioactive metabolites derived from aromatic ring oxidation were detected in vitro, and the latter metabolites were rapidly converted into the former with time, whereas only the [ 18 F]fluoride ion was detected in vivo. Similarly, the in vitro metabolism of [ 18 F]2 using either S9 fraction or microsomes showed the same pattern as the in vivo method using blood; however, the radioactive metabolites derived from aromatic ring oxidation were not detected in vivo. These results demonstrate that liver S9 fraction can be widely used to investigate the intermediate radioactive metabolites and to predict the in vivo metabolism of radiotracers

Invariant NKT cells with chimeric antigen receptor provide a novel platform for safe and effective cancer immunotherapy.

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Heczey, Andras; Liu, Daofeng; Tian, Gengwen; Courtney, Amy N; Wei, Jie; Marinova, Ekaterina; Gao, Xiuhua; Guo, Linjie; Yvon, Eric; Hicks, John; Liu, Hao; Dotti, Gianpietro; Metelitsa, Leonid S

2014-10-30

Advances in the design of chimeric antigen receptors (CARs) have improved the antitumor efficacy of redirected T cells. However, functional heterogeneity of CAR T cells limits their therapeutic potential and is associated with toxicity. We proposed that CAR expression in Vα24-invariant natural killer T (NKT) cells can build on the natural antitumor properties of these cells while their restriction by monomorphic CD1d limits toxicity. Primary human NKT cells were engineered to express a CAR against the GD2 ganglioside (CAR.GD2), which is highly expressed by neuroblastoma (NB). We compared CAR.GD2 constructs that encoded the CD3ζ chain alone, with CD28, 4-1BB, or CD28 and 4-1BB costimulatory endodomains. CAR.GD2 expression rendered NKT cells highly cytotoxic against NB cells without affecting their CD1d-dependent reactivity. We observed a striking T helper 1-like polarization of NKT cells by 4-1BB-containing CARs. Importantly, expression of both CD28 and 4-1BB endodomains in the CAR.GD2 enhanced in vivo persistence of NKT cells. These CAR.GD2 NKT cells effectively localized to the tumor site had potent antitumor activity, and repeat injections significantly improved the long-term survival of mice with metastatic NB. Unlike T cells, CAR.GD2 NKT cells did not induce graft-versus-host disease. These results establish the potential of NKT cells to serve as a safe and effective platform for CAR-directed cancer immunotherapy. © 2014 by The American Society of Hematology.

Dynamic changes of cytotoxic T lymphocytes (CTLs, natural killer (NK cells, and natural killer T (NKT cells in patients with acute hepatitis B infection

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Liu Bo

2011-05-01

Full Text Available Abstract Background The goal of this study is to observe changes in HBcAg-specific cytotoxic T lymphocytes (CTLs, natural killer (NK and natural killer T (NKT cells from peripheral blood and to relate such changes on viral clearance and liver injury in patients with acute hepatitis B (AHB. Methods Dynamic profiles on the frequency of HLA-A0201-restricted HBcAg18-27 pentamer complex (MHC-Pentamer-specific CTLs and lymphocyte subsets in AHB patients were analyzed in addition to liver function tests, HBV serological markers, and HBV DNA levels. ELISPOT was used to detect interferon-gamma (INF-γ secretion in specific CTLs stimulated with known T cell epitope peptides associated with HBV surface protein, polymerase, and core protein. Results HBV-specific CTL frequencies in AHB patients were much higher than in patients with chronic hepatitis B (CHB (p +CD8+ T cell numbers in AHB patients was more than observed in the healthy control group from the first to the fourth week after admission (p = 0.008 and 0.01, respectively; the number of CD3+CD8+ T cells and frequency of HBcAg18-27-specific CTLs in AHB patients reached peak levels at the second week after admission. NK and NKT cell numbers were negatively correlated with the frequency of HBcAg-specific CTLs (r = -0.266, p = 0.05. Conclusions Patients with AHB possess a higher frequency of HBcAg-specific CTLs than CHB patients. The frequency of specific CTLs in AHB patients is correlated with HBeAg clearance indicating that HBV-specific CTLs play an important role in viral clearance and the self-limited process of the disease. Furthermore, NK and NKT cells are likely involved in the early, non-specific immune response to clear the virus.

Hepatocyte Hypoxia Inducible Factor-1 Mediates the Development of Liver Fibrosis in a Mouse Model of Nonalcoholic Fatty Liver Disease.

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Omar A Mesarwi

Full Text Available Obstructive sleep apnea (OSA is associated with the progression of non-alcoholic fatty liver disease (NAFLD to steatohepatitis and fibrosis. This progression correlates with the severity of OSA-associated hypoxia. In mice with diet induced obesity, hepatic steatosis leads to liver tissue hypoxia, which worsens with exposure to intermittent hypoxia. Emerging data has implicated hepatocyte cell signaling as an important factor in hepatic fibrogenesis. We hypothesized that hepatocyte specific knockout of the oxygen sensing α subunit of hypoxia inducible factor-1 (HIF-1, a master regulator of the global response to hypoxia, may be protective against the development of liver fibrosis.Wild-type mice and mice with hepatocyte-specific HIF-1α knockout (Hif1a-/-hep were fed a high trans-fat diet for six months, as a model of NAFLD. Hepatic fibrosis was evaluated by Sirius red stain and hydroxyproline assay. Liver enzymes, fasting insulin, and hepatic triglyceride content were also assessed. Hepatocytes were isolated from Hif1a-/-hep mice and wild-type controls and were exposed to sustained hypoxia (1% O2 or normoxia (16% O2 for 24 hours. The culture media was used to reconstitute type I collagen and the resulting matrices were examined for collagen cross-linking.Wild-type mice on a high trans-fat diet had 80% more hepatic collagen than Hif1a-/-hep mice (2.21 μg collagen/mg liver tissue, versus 1.23 μg collagen/mg liver tissue, p = 0.03, which was confirmed by Sirius red staining. Body weight, liver weight, mean hepatic triglyceride content, and fasting insulin were similar between groups. Culture media from wild-type mouse hepatocytes exposed to hypoxia allowed for avid collagen cross-linking, but very little cross-linking was seen when hepatocytes were exposed to normoxia, or when hepatocytes from Hif1a-/-hep mice were used in hypoxia or normoxia.Hepatocyte HIF-1 mediates an increase in liver fibrosis in a mouse model of NAFLD, perhaps due to liver

Protein phosphatases 2A as well as reactive oxygen species involved in tributyltin-induced apoptosis in mouse livers.

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Zhang, Yali; Chen, Yonggang; Sun, Lijun; Liang, Jing; Guo, Zonglou; Xu, Lihong

2014-02-01

Tributyltin (TBT), a highly toxic environmental contaminant, has been shown to induce caspase-3-dependent apoptosis in human amniotic cells through protein phosphatase 2A (PP2A) inhibition and consequent JNK activation. This in vivo study was undertaken to further verify the results derived from our previous in vitro study. Mice were orally dosed with 0, 10, 20, and 60 mg/kg of body weight TBT, and levels of PP2A, reactive oxygen species (ROS), mitogen-activated protein kinase (MAPK), Bax/Bcl-2, and caspase-3 were detected in the mouse livers. Apoptosis was also evaluated using the TUNEL assay. The results showed that PP2A activity was inhibited, ROS levels were elevated, and MAPKs including ERK, JNK, and p38 were activated in mouse livers treated with the highest dose of TBT. Additionally, the ratio of Bax/Bcl-2 was increased, caspase-3 was activated, and apoptosis in mouse livers could be detected in the highest dose group. Therefore, a possible signaling pathway in TBT-induced apoptosis in mouse livers involves PP2A inhibition and ROS elevation serving a pivotal function as upstream activators of MAPKs; activation of MAPKs in turn leads to an increase in the Bax/Bcl-2 ratio, ultimately leading to the activation of caspase-3. The results give a comprehensive and novel description of the mechanism of TBT-induced toxicity. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

Regulation of retinoid X receptor gamma expression by fed state in mouse liver

International Nuclear Information System (INIS)

Park, Sangkyu; Lee, Yoo Jeong; Ko, Eun Hee; Kim, Jae-woo

2015-01-01

Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting–feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting–feeding cycle. - Highlights: • Refeeding increases the RXRγ expression level in mouse liver. • RXRγ expression is induced by high glucose condition in primary hepatocytes. • RXRγ and LXRα have synergistic effect on SREBP-1c promoter activity. • RXRγ binds to LXRE(-299/-280) located within SREBP-1c promoter region and interacts with LXRα

Regulation of retinoid X receptor gamma expression by fed state in mouse liver

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Park, Sangkyu, E-mail: 49park@cku.ac.kr [Department of Biochemistry, College of Medicine, Catholic Kwandong University, Gangneung 210-701 (Korea, Republic of); Lee, Yoo Jeong [Division of Metabolic Disease, Center for Biomedical Sciences, National Institute of Health Korea, Osong 361-709 (Korea, Republic of); Ko, Eun Hee [Department of Biochemistry and Molecular Biology, Integrated Genomic Research Center for Metabolic Regulation, Institute of Genetic Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Jae-woo [Department of Biochemistry and Molecular Biology, Integrated Genomic Research Center for Metabolic Regulation, Institute of Genetic Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 120-752 (Korea, Republic of)

2015-02-27

Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting–feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting–feeding cycle. - Highlights: • Refeeding increases the RXRγ expression level in mouse liver. • RXRγ expression is induced by high glucose condition in primary hepatocytes. • RXRγ and LXRα have synergistic effect on SREBP-1c promoter activity. • RXRγ binds to LXRE(-299/-280) located within SREBP-1c promoter region and interacts with LXRα.

Characterization of genetically engineered mouse hepatoma cells with inducible liver functions by overexpression of liver-enriched transcription factors.

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Yamamoto, Hideaki; Tonello, Jane Marie; Sambuichi, Takanori; Kawabe, Yoshinori; Ito, Akira; Kamihira, Masamichi

2018-01-01

New cell sources for the research and therapy of organ failure could significantly alleviate the shortage of donor livers that are available to patients who suffer from liver disease. Liver carcinoma derived cells, or hepatoma cells, are the ideal cells for developing bioartificial liver systems. Such cancerous liver cells are easy to prepare in large quantities and can be maintained over long periods under standard culture conditions, unlike primary hepatocytes. However, hepatoma cells possess only a fraction of the functions of primary hepatocytes. In a previous study, by transducing cells with liver-enriched transcription factors that could be inducibly overexpressed-hepatocyte nuclear factor (HNF)1α, HNF1β, HNF3β [FOXA2], HNF4α, HNF6, CCAAT/enhancer binding protein (C/EBP)α, C/EBPβ and C/EBPγ-we created mouse hepatoma cells with high liver-specific gene expression called the Hepa/8F5 cell line. In the present study, we performed functional and genetic analyses to characterize the Hepa/8F5 cell line. Further, in three-dimensional cultures, the function of these cells improved significantly compared to parental cells. Ultimately, these cells might become a new resource that can be used in basic and applied hepatic research. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

GM-CSF and IL-4 produced by NKT cells inversely regulate IL-1β production by macrophages.

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Ahn, Sehee; Jeong, Dongjin; Oh, Sae Jin; Ahn, Jiye; Lee, Seung Hyo; Chung, Doo Hyun

2017-02-01

Natural Killer T (NKT) cells are distinct T cell subset that link innate and adaptive immune responses. IL-1β, produced by various immune cells, plays a key role in the regulation of innate immunity in vivo. However, it is unclear whether NKT cells regulate IL-1β production by macrophages. To address this, we co-cultured NKT cells and peritoneal macrophages in the presence of TCR stimulation and inflammasome activators. Among cytokines secreted from NKT cells, GM-CSF enhanced IL-1β production by macrophages via regulating LPS-mediated pro-IL-1β expression and NLRP3-dependent inflammasome activation, whereas IL-4 enhanced M2-differentiation of macrophages and decreased IL-1β production. Together, our findings suggest the NKT cells have double-sided effects on IL-1β-mediated innate immune responses by producing IL-4 and GM-CSF. These findings may be helpful for a comprehensive understanding of NKT cell-mediated regulatory mechanisms of the pro-inflammatory effects of IL-1β in inflammatory diseases in vivo. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

NKT cell self-reactivity: evolutionary master key of immune homeostasis?

DEFF Research Database (Denmark)

Navikas, Shohreh

2011-01-01

Complex immune responses have evolved to protect multicellular organisms against the invasion of pathogens. This has exerted strong developmental pressure for specialized functions that can also limit damage to self-tissue. Two arms of immunity, the innate and adaptive immune system, have evolved...... through evolution by higher vertebrates could be related to their central function as master regulators of immune homeostasis that in part is shared with regulatory T cells. Hypothetical views on how self-reactive NKT cells secure such a central role will also be proposed.......Complex immune responses have evolved to protect multicellular organisms against the invasion of pathogens. This has exerted strong developmental pressure for specialized functions that can also limit damage to self-tissue. Two arms of immunity, the innate and adaptive immune system, have evolved....... The recent finding of self-peptide reactivity of NKT cells in the context of CD1d, with capacity to regulate multiple autoimmune and inflammatory conditions, motivates the current proposal that self-reactive NKT cells might be the ancestral link between present NK and T cells. Their parallel selection...

Maternal western diet primes non-alcoholic fatty liver disease in adult mouse offspring

NARCIS (Netherlands)

Pruis, M. G. M.; Lendvai, A.; Bloks, V. W.; Zwier, M. V.; Baller, J. F. W.; de Bruin, A.; Groen, A. K.; Plosch, T.

AimMetabolic programming via components of the maternal diet during gestation may play a role in the development of different aspects of the metabolic syndrome. Using a mouse model, we aimed to characterize the role of maternal western-type diet in the development of non-alcoholic fatty liver

Phenotypic and functional analyses of NK and NKT-like populations during the early stages of chikungunya infection.

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Thanapati, Subrat; Das, Rumki; Tripathy, Anuradha S

2015-01-01

The aim of this study was to characterize NK (CD56(+)CD3(-)) and NKT-like cell (CD56(+)CD3(+)) responses early after chikungunya infection. Expression profiling and functional analysis of T/NK/NKT-like cells were performed on samples from 56 acute and 31 convalescent chikungunya patients and 56 control individuals. The percentages of NK cells were high in both patient groups, whereas NKT-like cell percentages were high only in the convalescent group. The percentages of NKp30(+)CD3(-)CD56(+), NKp30(+)CD3(+)CD56(+), CD244(+)CD3(-)CD56(+), and CD244(+)CD3(+)CD56(+)cells were high, whereas the percentages of NKG2D(+)CD3(-)CD56(+) and NKG2D(+)CD3(+)CD56(+)cells were low in both patient groups. The percentages of NKp44(+)CD3(-)CD56(+) cells were high in both patient groups, whereas the percentages of NKp44(+)CD3(+)CD56(+) cells were higher in the acute group than in convalescent and control groups. The percentages of NKp46(+)CD3(-)CD56(+) cells were high in both patient groups. Higher percentages of perforin(+)CD3(-)CD56(+) and perforin(+)CD3(+)CD56(+) cells were observed in acute and convalescent patients, respectively. Higher cytotoxic activity was observed in acute patients than in controls. IFN-γ expression on NK cells of convalescent patients and on NKT-like cells of both patient groups was indicative of the regulatory role of NK and NKT-like cells. Collectively, these data showed that higher expression of activating receptors on NK/NKT-like cells and perforin(+) NK cells in acute patients could be responsible for increased cytotoxicity. The observed expression of perforin(+) NK cells in the acute phase and IFN-γ(+) NKT-like cells in the subsequent convalescent stage showed that NK/NKT-like cells mount an early and efficient response to chikungunya virus. Further study of the molecular mechanisms that limit viral dissemination/establishment of chronic disease will aid in understanding how NK/NKT-like cells control chikungunya infection.

Amelioration of NK cell function driven by Vα24+ invariant NKT cell activation in multiple myeloma.

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Iyoda, Tomonori; Yamasaki, Satoru; Hidaka, Michihiro; Kawano, Fumio; Abe, Yu; Suzuki, Kenshi; Kadowaki, Norimitsu; Shimizu, Kanako; Fujii, Shin-Ichiro

2018-02-01

NK cells represent a first line of immune defense, but are progressively dysregulated in multiple myeloma (MM) patients. To restore and facilitate their antitumor effect, NK cells are required in sufficient quantities and must be stimulated. We initially assessed the proportions of NKT and NK cells in 34 MM patients. The frequencies of both in PBMC populations correlated with those in BMMNCs irrespective of low BMMNC numbers. We then assessed the adjunctive effect of stimulating NKT cells with CD1d and α-GalCer complexes on the NK cells. The expression of NKG2D on CD56 dim CD16 + NK cells and DNAM-1 on CD56 bright CD16 - NK cells increased after NKT cell activation. Apparently, NK cell-mediated anti-tumor effects were dependent on NKG2D and DNAM-1 ligands on myeloma cells. Thus, NK cell function in patients could be ameliorated, beyond the effect of immunosuppression, by NKT cell activation. This NKT-driven NK cell therapy could represent a potential new treatment modality. Copyright © 2017 Elsevier Inc. All rights reserved.

Case Study: Polycystic Livers in a Transgenic Mouse Line

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Lovaglio, Jamie A.; Artwohl, James E.; Ward, Christopher J.; Diekwisch, Thomas G. H.; Ito, Yoshihiro; Fortman, Jeffrey D.

2014-04-01

Three mice (2 male, 1 female; age, 5 to 16 mo) from a mouse line transgenic for keratin 14 (K14)-driven LacZ expression and on an outbred Crl:CD1(ICR) background, were identified as having distended abdomens and livers that were diffusely enlarged by numerous cysts (diameter, 0.1 to 2.0 cm). Histopathology revealed hepatic cysts lined by biliary type epithelium and mild chronic inflammation, and confirmed the absence of parasites. Among 21 related mice, 5 additional affected mice were identified via laparotomy. Breeding of these 5 mice (after 5 mo of age) did not result in any offspring; the K14 mice with olycystic livers failed to reproduce. Affected male mice had degenerative testicular lesions, and their sperm was immotile. Nonpolycystic K14 control male mice bred well, had no testicular lesions, and had appropriate sperm motility. Genetic analysis did not identify an association of this phenotype with the transgene or insertion site.

The actin cytoskeleton modulates the activation of iNKT cells by segregating CD1d nanoclusters on antigen-presenting cells

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Torreno-Pina, Juan A.; Manzo, Carlo; Salio, Mariolina; Aichinger, Michael C.; Oddone, Anna; Lakadamyali, Melike; Shepherd, Dawn; Besra, Gurdyal S.; Cerundolo, Vincenzo

2016-01-01

Invariant natural killer T (iNKT) cells recognize endogenous and exogenous lipid antigens presented in the context of CD1d molecules. The ability of iNKT cells to recognize endogenous antigens represents a distinct immune recognition strategy, which underscores the constitutive memory phenotype of iNKT cells and their activation during inflammatory conditions. However, the mechanisms regulating such “tonic” activation of iNKT cells remain unclear. Here, we show that the spatiotemporal distribution of CD1d molecules on the surface of antigen-presenting cells (APCs) modulates activation of iNKT cells. By using superresolution microscopy, we show that CD1d molecules form nanoclusters at the cell surface of APCs, and their size and density are constrained by the actin cytoskeleton. Dual-color single-particle tracking revealed that diffusing CD1d nanoclusters are actively arrested by the actin cytoskeleton, preventing their further coalescence. Formation of larger nanoclusters occurs in the absence of interactions between CD1d cytosolic tail and the actin cytoskeleton and correlates with enhanced iNKT cell activation. Importantly and consistently with iNKT cell activation during inflammatory conditions, exposure of APCs to the Toll-like receptor 7/8 agonist R848 increases nanocluster density and iNKT cell activation. Overall, these results define a previously unidentified mechanism that modulates iNKT cell autoreactivity based on the tight control by the APC cytoskeleton of the sizes and densities of endogenous antigen-loaded CD1d nanoclusters. PMID:26798067

Heme synthesis in normal mouse liver and mouse liver tumors

International Nuclear Information System (INIS)

Stout, D.L.; Becker, F.F.

1990-01-01

Hepatic cancers from mice and rats demonstrate decreased levels of delta-aminolevulinic acid synthase, the rate-limiting enzyme in the heme synthetic pathway, and increased heme oxygenase, the heme-catabolizing enzyme. These findings suggest that diminution of P-450, b5, and catalase in these lesions may result from a heme supply that is limited by decreased heme synthesis and increased heme catabolism. Heme synthesis was measured in mouse liver tumors (MLT) and adjacent tumor-free lobes (BKG) by administering the radiolabeled heme precursors 55 FeCl3 and [2- 14 C]glycine and subsequently extracting the heme for determination of specific activity. Despite reduced delta-aminolevulinic acid synthase activity in MLT, both tissues incorporated [2-14C]glycine into heme at similar rates. At early time points, heme extracted from MLT contained less 55Fe than that from BKG. This was attributed to the findings that MLT took up 55Fe at a slower rate than BKG and had larger iron stores than BKG. The amount of heme per milligram of protein was also similar in both tissues. These findings militate against the hypothesis that diminished hemoprotein levels in MLT result from limited availability of heme. It is probable, therefore, that decreased hemoprotein levels in hepatic tumors are linked to a general program of dedifferentiation associated with the cancer phenotype. Diminution of hemoprotein in MLT may result in a relatively increased intracellular heme pool. delta-Aminolevulinic acid synthase and heme oxygenase are, respectively, negatively and positively regulated by heme. Thus, their alteration in MLT may be due to the regulatory influences of the heme pool

Tbx3 Promotes Liver Bud Expansion During Mouse Development by Suppression of Cholangiocyte Differentiation

NARCIS (Netherlands)

Lüdtke, Timo H.-W.; Christoffels, Vincent M.; Petry, Marianne; Kispert, Andreas

2009-01-01

After specification of the hepatic endoderm, mammalian liver organogenesis progresses through a series of morphological stages that culminate in the migration of hepatocytes into the underlying mesenchyme to populate the hepatic lobes. Here, we show that in the mouse the transcriptional repressor

Protective role of NKT cells and macrophage M2-driven phenotype in bleomycin-induced pulmonary fibrosis.

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Grabarz, Felipe; Aguiar, Cristhiane Favero; Correa-Costa, Matheus; Braga, Tárcio Teodoro; Hyane, Meire I; Andrade-Oliveira, Vinícius; Landgraf, Maristella Almeida; Câmara, Niels Olsen Saraiva

2018-04-01

Pulmonary fibrosis is a result of an abnormal wound healing in lung tissue triggered by an excessive accumulation of extracellular matrix proteins, loss of tissue elasticity, and debit of ventilatory function. NKT cells are a major source of Th1 and Th2 cytokines and may be crucial in the polarization of M1/M2 macrophages in pulmonary fibrogenesis. Although there appears to be constant scientific progress in that field, pulmonary fibrosis still exhibits no current cure. From these facts, we hypothesized that NKT cells could influence the development of pulmonary fibrosis via modulation of macrophage activation. Wild type (WT) and NKT type I cell-deficient mice (Jα18 -/- ) were subjected to the protocol of bleomycin-induced pulmonary fibrosis with or without treatment with NKT cell agonists α-galactosylceramide and sulfatide. The participation of different cell populations, collagen deposition, and protein levels of different cytokines involved in inflammation and fibrosis was evaluated. The results indicate a benign role of NKT cells in Jα18 -/- mice and in wild-type α-galactosylceramide-sulfatide-treated groups. These animals presented lower levels of collagen deposition, fibrogenic molecules such as TGF-β and vimentin and improved survival rates. In contrast, WT mice developed a Th2-driven response augmenting IL-4, 5, and 13 protein synthesis and increased collagen deposition. Furthermore, the arginase-1 metabolic pathway was downregulated in wild-type NKT-activated and knockout mice indicating lower activity of M2 macrophages in lung tissue. Hence, our data suggest that NKT cells play a protective role in this experimental model by down modulating the Th2 milieu, inhibiting M2 polarization and finally preventing fibrosis.

NKT cells contribute to basal IL-4 production but are not required to induce experimental asthma.

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McKnight, Christopher G; Morris, Suzanne C; Perkins, Charles; Zhu, Zhenqi; Hildeman, David A; Bendelac, Albert; Finkelman, Fred D

2017-01-01

CD1d-deficiency results in a selective deletion of NKT cells in mice that is reported to prevent murine allergic airway disease (AAD). Because we find 2-3 fold lower basal IL-4 production in CD1d- mice than in wild-type (WT) mice, we hypothesized that the contribution made by NKT cells to AAD would depend on the strength of the stimulus used to induce the disease. Consequently, we compared CD1d-deficient mice to WT mice in the development of AAD, using several models of disease induction that differed in the type and dose of allergen, the site of sensitization and the duration of immunization. Surprisingly we found equivalent allergic inflammation and airway disease in WT and CD1d- mice in all models investigated. Consistent with this, NKT cells constituted only ~2% of CD4+ T cells in the lungs of mice with AAD, and IL-4-transcribing NKT cells did not expand with disease induction. Concerned that the congenital absence of NKT cells might have caused a compensatory shift within the immune response, we administered an anti-CD1d monoclonal Ab (mAb) to block NKT function before airway treatments, before or after systemic sensitization to antigen. Such Ab treatment did not affect disease severity. We suggest that the differences reported in the literature regarding the significance of NKT cells in the induction of allergic airway disease may have less to do with the methods used to study the disease and more to do with the animals themselves and/or the facilities used to house them.

NKT cells contribute to basal IL-4 production but are not required to induce experimental asthma.

Directory of Open Access Journals (Sweden)

Christopher G McKnight

Full Text Available CD1d-deficiency results in a selective deletion of NKT cells in mice that is reported to prevent murine allergic airway disease (AAD. Because we find 2-3 fold lower basal IL-4 production in CD1d- mice than in wild-type (WT mice, we hypothesized that the contribution made by NKT cells to AAD would depend on the strength of the stimulus used to induce the disease. Consequently, we compared CD1d-deficient mice to WT mice in the development of AAD, using several models of disease induction that differed in the type and dose of allergen, the site of sensitization and the duration of immunization. Surprisingly we found equivalent allergic inflammation and airway disease in WT and CD1d- mice in all models investigated. Consistent with this, NKT cells constituted only ~2% of CD4+ T cells in the lungs of mice with AAD, and IL-4-transcribing NKT cells did not expand with disease induction. Concerned that the congenital absence of NKT cells might have caused a compensatory shift within the immune response, we administered an anti-CD1d monoclonal Ab (mAb to block NKT function before airway treatments, before or after systemic sensitization to antigen. Such Ab treatment did not affect disease severity. We suggest that the differences reported in the literature regarding the significance of NKT cells in the induction of allergic airway disease may have less to do with the methods used to study the disease and more to do with the animals themselves and/or the facilities used to house them.

Critical role for invariant chain in CD1d-mediated selection and maturation of Vα14-invariant NKT cells.

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Sillé, Fenna C M; Martin, Constance; Jayaraman, Pushpa; Rothchild, Alissa; Besra, Gurdyal S; Behar, Samuel M; Boes, Marianne

2011-09-30

The development and maturation of Vα14 invariant (i)NKT cells in mice requires CD1d-mediated lipid antigen presentation in the thymus and the periphery. Cortical thymocytes mediate positive selection, while professional APCs are involved in thymic negative selection and in terminal maturation of iNKT cells in the periphery. CD1d requires entry in the endosomal pathway to allow antigen acquisition for assembly as lipid/CD1d complexes for display to iNKT cells. This process involves tyrosine-based sorting motifs in the CD1d cytoplasmic tail and invariant chain (Ii) that CD1d associates with in the endoplasmic reticulum. The function of Ii in iNKT cell thymic development and peripheral maturation had not been fully understood. Using mice deficient in Ii and the Ii-processing enzyme cathepsin S (catS), we addressed this question. Ii(-/-) mice but not catS(-/-) mice developed significantly fewer iNKT cells in thymus, that were less mature as measured by CD44 and NK1.1 expression. Ii(-/-) mice but not catS(-/-) mice developed fewer Vβ7(+) cells in their iNKT TCR repertoire than WT counterparts, indicative of a change in endogenous glycolipid antigen/CD1d-mediated iNKT cell selection. Finally, using a Mycobacterium tuberculosis infection model in macrophages, we show that iNKT developed in Ii(-/-) but not catS(-/-) mice have defective effector function. Our data support a role for professional APCs expressing Ii, but no role for catS in the thymic development and peripheral terminal maturation of iNKT cells. Copyright © 2011 Elsevier B.V. All rights reserved.

Bacillus anthracis lethal toxin disrupts TCR signaling in CD1d-restricted NKT cells leading to functional anergy.

Directory of Open Access Journals (Sweden)

Sunil K Joshi

2009-09-01

Full Text Available Exogenous CD1d-binding glycolipid (alpha-Galactosylceramide, alpha-GC stimulates TCR signaling and activation of type-1 natural killer-like T (NKT cells. Activated NKT cells play a central role in the regulation of adaptive and protective immune responses against pathogens and tumors. In the present study, we tested the effect of Bacillus anthracis lethal toxin (LT on NKT cells both in vivo and in vitro. LT is a binary toxin known to suppress host immune responses during anthrax disease and intoxicates cells by protective antigen (PA-mediated intracellular delivery of lethal factor (LF, a potent metalloprotease. We observed that NKT cells expressed anthrax toxin receptors (CMG-2 and TEM-8 and bound more PA than other immune cell types. A sub-lethal dose of LT administered in vivo in C57BL/6 mice decreased expression of the activation receptor NKG2D by NKT cells but not by NK cells. The in vivo administration of LT led to decreased TCR-induced cytokine secretion but did not affect TCR expression. Further analysis revealed LT-dependent inhibition of TCR-stimulated MAP kinase signaling in NKT cells attributable to LT cleavage of the MAP kinase kinase MEK-2. We propose that Bacillus anthracis-derived LT causes a novel form of functional anergy in NKT cells and therefore has potential for contributing to immune evasion by the pathogen.

Thymidine kinase 2 deficiency-induced mtDNA depletion in mouse liver leads to defect β-oxidation.

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Xiaoshan Zhou

Full Text Available Thymidine kinase 2 (TK2 deficiency in humans causes mitochondrial DNA (mtDNA depletion syndrome. To study the molecular mechanisms underlying the disease and search for treatment options, we previously generated and described a TK2 deficient mouse strain (TK2(-/- that progressively loses its mtDNA. The TK2(-/- mouse model displays symptoms similar to humans harboring TK2 deficient infantile fatal encephalomyopathy. Here, we have studied the TK2(-/- mouse model to clarify the pathological role of progressive mtDNA depletion in liver for the severe outcome of TK2 deficiency. We observed that a gradual depletion of mtDNA in the liver of the TK2(-/- mice was accompanied by increasingly hypertrophic mitochondria and accumulation of fat vesicles in the liver cells. The levels of cholesterol and nonesterified fatty acids were elevated and there was accumulation of long chain acylcarnitines in plasma of the TK2(-/- mice. In mice with hepatic mtDNA levels below 20%, the blood sugar and the ketone levels dropped. These mice also exhibited reduced mitochondrial β-oxidation due to decreased transport of long chain acylcarnitines into the mitochondria. The gradual loss of mtDNA in the liver of the TK2(-/- mice causes impaired mitochondrial function that leads to defect β-oxidation and, as a result, insufficient production of ketone bodies and glucose. This study provides insight into the mechanism of encephalomyopathy caused by TK2 deficiency-induced mtDNA depletion that may be used to explore novel therapeutic strategies.

Thymidine kinase 2 deficiency-induced mtDNA depletion in mouse liver leads to defect β-oxidation.

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Zhou, Xiaoshan; Kannisto, Kristina; Curbo, Sophie; von Döbeln, Ulrika; Hultenby, Kjell; Isetun, Sindra; Gåfvels, Mats; Karlsson, Anna

2013-01-01

Thymidine kinase 2 (TK2) deficiency in humans causes mitochondrial DNA (mtDNA) depletion syndrome. To study the molecular mechanisms underlying the disease and search for treatment options, we previously generated and described a TK2 deficient mouse strain (TK2(-/-)) that progressively loses its mtDNA. The TK2(-/-) mouse model displays symptoms similar to humans harboring TK2 deficient infantile fatal encephalomyopathy. Here, we have studied the TK2(-/-) mouse model to clarify the pathological role of progressive mtDNA depletion in liver for the severe outcome of TK2 deficiency. We observed that a gradual depletion of mtDNA in the liver of the TK2(-/-) mice was accompanied by increasingly hypertrophic mitochondria and accumulation of fat vesicles in the liver cells. The levels of cholesterol and nonesterified fatty acids were elevated and there was accumulation of long chain acylcarnitines in plasma of the TK2(-/-) mice. In mice with hepatic mtDNA levels below 20%, the blood sugar and the ketone levels dropped. These mice also exhibited reduced mitochondrial β-oxidation due to decreased transport of long chain acylcarnitines into the mitochondria. The gradual loss of mtDNA in the liver of the TK2(-/-) mice causes impaired mitochondrial function that leads to defect β-oxidation and, as a result, insufficient production of ketone bodies and glucose. This study provides insight into the mechanism of encephalomyopathy caused by TK2 deficiency-induced mtDNA depletion that may be used to explore novel therapeutic strategies.

Evaluation of immunological escape mechanisms in a mouse model of colorectal liver metastases

International Nuclear Information System (INIS)

Grimm, Martin; Thalheimer, Andreas; Gasser, Martin; Bueter, Marco; Strehl, Johanna; Wang, Johann; Nichiporuk, Ekaterina; Meyer, Detlef; Germer, Christoph T; Waaga-Gasser, Ana M

2010-01-01

The local and systemic activation and regulation of the immune system by malignant cells during carcinogenesis is highly complex with involvement of the innate and acquired immune system. Despite the fact that malignant cells do have antigenic properties their immunogenic effects are minor suggesting tumor induced mechanisms to circumvent cancer immunosurveillance. The aim of this study is the analysis of tumor immune escape mechanisms in a colorectal liver metastases mouse model at different points in time during tumor growth. CT26.WT murine colon carcinoma cells were injected intraportally in Balb/c mice after median laparotomy using a standardized injection technique. Metastatic tumor growth in the liver was examined by standard histological procedures at defined points in time during metastatic growth. Liver tissue with metastases was additionally analyzed for cytokines, T cell markers and Fas/Fas-L expression using immunohistochemistry, immunofluorescence and RT-PCR. Comparisons were performed by analysis of variance or paired and unpaired t test when appropriate. Intraportal injection of colon carcinoma cells resulted in a gradual and time dependent metastatic growth. T cells of regulatory phenotype (CD4+CD25+Foxp3+) which might play a role in protumoral immune response were found to infiltrate peritumoral tissue increasingly during carcinogenesis. Expression of cytokines IL-10, TGF-β and TNF-α were increased during tumor growth whereas IFN-γ showed a decrease of the expression from day 10 on following an initial increase. Moreover, liver metastases of murine colon carcinoma show an up-regulation of FAS-L on tumor cell surface with a decreased expression of FAS from day 10 on. CD8+ T cells express FAS and show an increased rate of apoptosis at perimetastatic location. This study describes cellular and macromolecular changes contributing to immunological escape mechanisms during metastatic growth in a colorectal liver metastases mouse model simulating the

[IL-2 stimulated responses of CD3(+) CD56(+) NKT cells in pulmonary tuberculosis patients].

Science.gov (United States)

Yao, Chun-Yan; Wang, Zhao-Hua; Jiang, Li-Na; Peng, Mei-Yu; Wang, Jing; Li, Bai-Qing

2010-09-01

To observe the activation and proliferation characteristics of IL-2 stimulated CD3(+);CD56(+); NKT cells in pulmonary tuberculosis (PTB) patients. Peripheral blood mononuclear cells (PBMCs) from PTB patients and normal subjects were stimulated with IL-2 and cultured for different time points. The CD69 expression on and amount of the CD3(+);CD56(+); NKT cells were detected by multi fluorescence staining and flow cytometry at different time of stimulation and culture. There was no significant difference in percentage of NKT cells between PTB patients and normal healthy controls before culture. When IL-2 was used to stimulate for 0 h, 8 h, 16 h, 40 h and 64 h, the expression of CD69 on NKT cells in normal controls and PTB patients increased significantly, but the CD69 expression level of NKT cells in PTB patients was significantly higher than that in normal persons(PNKT cells increased from (3.44+/-1.20)x10(4); to (323.23+/-75.98) x10(4); (PNKT cells increased from (5.57+/-5.16)x10(4); to (1475.05+/-868.98)x10(4); (PNKT cells in PTB patients present with high activation but low proliferation after stimulated by IL-2.

Clinical development of a novel CD1d-binding NKT cell ligand as a vaccine adjuvant

OpenAIRE

Padte, Neal N.; Li, Xiangming; Tsuji, Moriya; Vasan, Sandhya

2010-01-01

Natural killer T (NKT) cells are known to play a role against certain microbial infections, including malaria and HIV, two major global infectious diseases. Strategies that acn harness and amplify the immunotherapeutic potential of NKT cells can serve as powerful tools in the fight against such diseases. 7DW8-5, a novel glycolipid, may be one such tool. The interaction of 7DW8-5 with CD1d molecules induces activation of NKT cells, thereby activating various immune-competent cells including de...

Colonic inflammation in mice is improved by cigarette smoke through iNKT cells recruitment.

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Muriel Montbarbon

Full Text Available Cigarette smoke (CS protects against intestinal inflammation during ulcerative colitis. Immunoregulatory mechanisms sustaining this effect remain unknown. The aim of this study was to assess the effects of CS on experimental colitis and to characterize the intestinal inflammatory response at the cellular and molecular levels. Using the InExpose® System, a smoking device accurately reproducing human smoking habit, we pre-exposed C57BL/6 mice for 2 weeks to CS, and then we induced colitis by administration of dextran sodium sulfate (DSS. This system allowed us to demonstrate that CS exposure improved colonic inflammation (significant decrease in clinical score, body weight loss and weight/length colonic ratio. This improvement was associated with a significant decrease in colonic proinflammatory Th1/Th17 cytokine expression, as compared to unexposed mice (TNF (p=0.0169, IFNγ (p<0.0001, and IL-17 (p=0.0008. Smoke exposure also induced an increased expression of IL-10 mRNA (p=0.0035 and a marked recruitment of iNKT (invariant Natural Killer T; CD45+ TCRβ+ CD1d tetramer+ cells in the colon of DSS-untreated mice. Demonstration of the role of iNKT cells in CS-dependent colitis improvement was performed using two different strains of NKT cells deficient mice. Indeed, in Jα18KO and CD1dKO animals, CS exposure failed to induce significant regulation of DSS-induced colitis both at the clinical and molecular levels. Thus, our study demonstrates that iNKT cells are pivotal actors in the CS-dependent protection of the colon. These results highlight the role of intestinal iNKT lymphocytes and their responsiveness to environmental stimuli. Targeting iNKT cells would represent a new therapeutic way for inflammatory bowel diseases.

Gene Expression Profile Change and Associated Physiological and Pathological Effects in Mouse Liver Induced by Fasting and Refeeding

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Zhang, Fang; Xu, Xiang; Zhou, Ben; He, Zhishui; Zhai, Qiwei

2011-01-01

Food availability regulates basal metabolism and progression of many diseases, and liver plays an important role in these processes. The effects of food availability on digital gene expression profile, physiological and pathological functions in liver are yet to be further elucidated. In this study, we applied high-throughput sequencing technology to detect digital gene expression profile of mouse liver in fed, fasted and refed states. Totally 12162 genes were detected, and 2305 genes were significantly regulated by food availability. Biological process and pathway analysis showed that fasting mainly affected lipid and carboxylic acid metabolic processes in liver. Moreover, the genes regulated by fasting and refeeding in liver were mainly enriched in lipid metabolic process or fatty acid metabolism. Network analysis demonstrated that fasting mainly regulated Drug Metabolism, Small Molecule Biochemistry and Endocrine System Development and Function, and the networks including Lipid Metabolism, Small Molecule Biochemistry and Gene Expression were affected by refeeding. In addition, FunDo analysis showed that liver cancer and diabetes mellitus were most likely to be affected by food availability. This study provides the digital gene expression profile of mouse liver regulated by food availability, and demonstrates the main biological processes, pathways, gene networks and potential hepatic diseases regulated by fasting and refeeding. These results show that food availability mainly regulates hepatic lipid metabolism and is highly correlated with liver-related diseases including liver cancer and diabetes. PMID:22096593

Forming a complex with MHC class I molecules interferes with mouse CD1d functional expression.

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Renukaradhya J Gourapura

Full Text Available CD1d molecules are structurally similar to MHC class I, but present lipid antigens as opposed to peptides. Here, we show that MHC class I molecules physically associate with (and regulate the functional expression of mouse CD1d on the surface of cells. Low pH (3.0 acid stripping of MHC class I molecules resulted in increased surface expression of murine CD1d on antigen presenting cells as well as augmented CD1d-mediated antigen presentation to NKT cells. Consistent with the above results, TAP1-/- mice were found to have a higher percentage of type I NKT cells as compared to wild type mice. Moreover, bone marrow-derived dendritic cells from TAP1-/- mice showed increased antigen presentation by CD1d compared to wild type mice. Together, these results suggest that MHC class I molecules can regulate NKT cell function, in part, by masking CD1d.

Building new businesses through corporate venturing at the danish NKT group

DEFF Research Database (Denmark)

Skat-Rørdam, Peter

2005-01-01

An in depth case study of how the danish NKT group used corporate venturing over a 25 year period to build new businesses. The study provides insights on purposes, drivers and results of corporate venturing and examines factors contributing to venture success and failure.......An in depth case study of how the danish NKT group used corporate venturing over a 25 year period to build new businesses. The study provides insights on purposes, drivers and results of corporate venturing and examines factors contributing to venture success and failure....

NK-, NKT- and CD8-Derived IFNγ Drives Myeloid Cell Activation and Erythrophagocytosis, Resulting in Trypanosomosis-Associated Acute Anemia.

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Jennifer Cnops

2015-06-01

Full Text Available African trypanosomes are the causative agents of Human African Trypanosomosis (HAT/Sleeping Sickness and Animal African Trypanosomosis (AAT/Nagana. A common hallmark of African trypanosome infections is inflammation. In murine trypanosomosis, the onset of inflammation occurs rapidly after infection and is manifested by an influx of myeloid cells in both liver and spleen, accompanied by a burst of serum pro-inflammatory cytokines. Within 48 hours after reaching peak parasitemia, acute anemia develops and the percentage of red blood cells drops by 50%. Using a newly developed in vivo erythrophagocytosis assay, we recently demonstrated that activated cells of the myeloid phagocytic system display enhanced erythrophagocytosis causing acute anemia. Here, we aimed to elucidate the mechanism and immune pathway behind this phenomenon in a murine model for trypanosomosis. Results indicate that IFNγ plays a crucial role in the recruitment and activation of erythrophagocytic myeloid cells, as mice lacking the IFNγ receptor were partially protected against trypanosomosis-associated inflammation and acute anemia. NK and NKT cells were the earliest source of IFNγ during T. b. brucei infection. Later in infection, CD8+ and to a lesser extent CD4+ T cells become the main IFNγ producers. Cell depletion and transfer experiments indicated that during infection the absence of NK, NKT and CD8+ T cells, but not CD4+ T cells, resulted in a reduced anemic phenotype similar to trypanosome infected IFNγR-/- mice. Collectively, this study shows that NK, NKT and CD8+ T cell-derived IFNγ is a critical mediator in trypanosomosis-associated pathology, driving enhanced erythrophagocytosis by myeloid phagocytic cells and the induction of acute inflammation-associated anemia.

Increased Intraepithelial Vα24 Invariant NKT Cells in the Celiac Duodenum

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Montalvillo, Enrique; Bernardo, David; Martínez-Abad, Beatriz; Allegretti, Yessica; Fernández-Salazar, Luis; Calvo, Carmen; Chirdo, Fernando G.; Garrote, José A.; Arranz, Eduardo

2015-01-01

Celiac Disease (CD) is an interferon (IFN)γ-mediated duodenal hypersensitivity to wheat gluten occurring in genetically predisposed individuals. Gluten-free diet (GFD) leads to a complete remission of the disease. Vα24-restricted invariant NKT (iNKT) cells are important to maintain immune homeostasis in the gut mucosa because of their unique capacity to rapidly produce large quantities of both T-helper (Th)1 and Th2 cytokines upon stimulation. We studied the presence of these cells in the CD duodenum. Duodenal biopsies were obtained from 45 untreated-CD patients (uCD), 15 Gluten Free Diet-CD patients (GFD-CD), 44 non-inflamed non-CD controls (C-controls) and 15 inflamed non-CD controls (I-controls). Two populations from Spain and Argentina were recruited. Messenger RNA (mRNA) expression of Vα24-Jα18 (invariant TCRα chain of human iNKT cells), IFNγ and intracellular transcription factor Forkhead Box P3 (Foxp3), and flow cytometry intraepithelial lymphocyte (IEL) profile were determined. Both uCD and GFD-CD patients had higher Vα24-Jα18 mRNA levels than non-CD controls (I and C-controls). The expression of Vα24-Jα18 correlated with Marsh score for the severity of mucosal lesion and also with increased mRNA IFNγ levels. uCD and GFD-CD patients had decreased mRNA expression of FoxP3 but increased expression of Vα24-Jα18, which revealed a CD-like molecular profile. Increased numbers of iNKT cells were confirmed by flow cytometry within the intraepithelial lymphocyte compartment of uCD and GFD-CD patients and correlated with Vα24-Jα18 mRNA expression. In conclusion, we have found an increased number of iNKT cells in the duodenum from both uCD and GFD-CD patients, irrespective of the mucosal status. A CD-like molecular profile, defined by an increased mRNA expression of Vα24-Jα18 together with a decreased expression of FoxP3, may represent a pro-inflammatory signature of the CD duodenum. PMID:26529008

Cross-talk between cd1d-restricted nkt cells and γδ cells in t regulatory cell response

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Huber Sally A

2011-01-01

Full Text Available Abstract CD1d is a non-classical major histocompatibility class 1-like molecule which primarily presents either microbial or endogenous glycolipid antigens to T cells involved in innate immunity. Natural killer T (NKT cells and a subpopulation of γδ T cells expressing the Vγ4 T cell receptor (TCR recognize CD1d. NKT and Vγ4 T cells function in the innate immune response via rapid activation subsequent to infection and secrete large quantities of cytokines that both help control infection and modulate the developing adaptive immune response. T regulatory cells represent one cell population impacted by both NKT and Vγ4 T cells. This review discusses the evidence that NKT cells promote T regulatory cell activation both through direct interaction of NKT cell and dendritic cells and through NKT cell secretion of large amounts of TGFβ, IL-10 and IL-2. Recent studies have shown that CD1d-restricted Vγ4 T cells, in contrast to NKT cells, selectively kill T regulatory cells through a caspase-dependent mechanism. Vγ4 T cell elimination of the T regulatory cell population allows activation of autoimmune CD8+ effector cells leading to severe cardiac injury in a coxsackievirus B3 (CVB3 myocarditis model in mice. CD1d-restricted immunity can therefore lead to either immunosuppression or autoimmunity depending upon the type of innate effector dominating during the infection.

Dissection of SAP-dependent and SAP-independent SLAM family signaling in NKT cell development and humoral immunity

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Cai, Chenxu; Liu, Guangao; Wang, Yuande; Du, Juan; Lin, Xin; Yang, Meixiang

2017-01-01

Signaling lymphocytic activation molecule (SLAM)–associated protein (SAP) mutations in X-linked lymphoproliferative disease (XLP) lead to defective NKT cell development and impaired humoral immunity. Because of the redundancy of SLAM family receptors (SFRs) and the complexity of SAP actions, how SFRs and SAP mediate these processes remains elusive. Here, we examined NKT cell development and humoral immunity in mice completely deficient in SFR. We found that SFR deficiency severely impaired NKT cell development. In contrast to SAP deficiency, SFR deficiency caused no apparent defect in follicular helper T (TFH) cell differentiation. Intriguingly, the deletion of SFRs completely rescued the severe defect in TFH cell generation caused by SAP deficiency, whereas SFR deletion had a minimal effect on the defective NKT cell development in SAP-deficient mice. These findings suggest that SAP-dependent activating SFR signaling is essential for NKT cell selection; however, SFR signaling is inhibitory in SAP-deficient TFH cells. Thus, our current study revises our understanding of the mechanisms underlying T cell defects in patients with XLP. PMID:28049627

Dissection of SAP-dependent and SAP-independent SLAM family signaling in NKT cell development and humoral immunity.

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Chen, Shasha; Cai, Chenxu; Li, Zehua; Liu, Guangao; Wang, Yuande; Blonska, Marzenna; Li, Dan; Du, Juan; Lin, Xin; Yang, Meixiang; Dong, Zhongjun

2017-02-01

Signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) mutations in X-linked lymphoproliferative disease (XLP) lead to defective NKT cell development and impaired humoral immunity. Because of the redundancy of SLAM family receptors (SFRs) and the complexity of SAP actions, how SFRs and SAP mediate these processes remains elusive. Here, we examined NKT cell development and humoral immunity in mice completely deficient in SFR. We found that SFR deficiency severely impaired NKT cell development. In contrast to SAP deficiency, SFR deficiency caused no apparent defect in follicular helper T (T FH ) cell differentiation. Intriguingly, the deletion of SFRs completely rescued the severe defect in T FH cell generation caused by SAP deficiency, whereas SFR deletion had a minimal effect on the defective NKT cell development in SAP-deficient mice. These findings suggest that SAP-dependent activating SFR signaling is essential for NKT cell selection; however, SFR signaling is inhibitory in SAP-deficient T FH cells. Thus, our current study revises our understanding of the mechanisms underlying T cell defects in patients with XLP. © 2017 Chen et al.

Genome-Wide Profiling of Liver X Receptor, Retinoid X Receptor, and Peroxisome Proliferator-Activated Receptor α in Mouse Liver Reveals Extensive Sharing of Binding Sites

DEFF Research Database (Denmark)

Boergesen, Michael; Pedersen, Thomas Åskov; Gross, Barbara

2012-01-01

and correlate with an LXR-dependent hepatic induction of lipogenic genes. To further investigate the roles of RXR and LXR in the regulation of hepatic gene expression, we have mapped the ligand-regulated genome-wide binding of these factors in mouse liver. We find that the RXR agonist bexarotene primarily......The liver X receptors (LXRs) are nuclear receptors that form permissive heterodimers with retinoid X receptor (RXR) and are important regulators of lipid metabolism in the liver. We have recently shown that RXR agonist-induced hypertriglyceridemia and hepatic steatosis in mice are dependent on LXRs...

in Human Liver Diseases

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Minoru Fujimoto

2010-01-01

Full Text Available Toll-like receptor (TLR signaling pathways are strictly coordinated by several mechanisms to regulate adequate innate immune responses. Recent lines of evidence indicate that the suppressor of cytokine signaling (SOCS family proteins, originally identified as negative-feedback regulators in cytokine signaling, are involved in the regulation of TLR-mediated immune responses. SOCS1, a member of SOCS family, is strongly induced upon TLR stimulation. Cells lacking SOCS1 are hyperresponsive to TLR stimulation. Thus, SOCS1 is an important regulator for both cytokine and TLR-induced responses. As an immune organ, the liver contains various types of immune cells such as T cells, NK cells, NKT cells, and Kupffer cells and is continuously challenged with gut-derived bacterial and dietary antigens. SOCS1 may be implicated in pathophysiology of the liver. The studies using SOCS1-deficient mice revealed that endogenous SOCS1 is critical for the prevention of liver diseases such as hepatitis, cirrhosis, and cancers. Recent studies on humans suggest that SOCS1 is involved in the development of various liver disorders in humans. Thus, SOCS1 and other SOCS proteins are potential targets for the therapy of human liver diseases.

MicroRNA regulation in Ames dwarf mouse liver may contribute to delayed aging.

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Bates, David J; Li, Na; Liang, Ruqiang; Sarojini, Harshini; An, Jin; Masternak, Michal M; Bartke, Andrzej; Wang, Eugenia

2010-02-01

The Ames dwarf mouse is well known for its remarkable propensity to delay the onset of aging. Although significant advances have been made demonstrating that this aging phenotype results primarily from an endocrine imbalance, the post-transcriptional regulation of gene expression and its impact on longevity remains to be explored. Towards this end, we present the first comprehensive study by microRNA (miRNA) microarray screening to identify dwarf-specific lead miRNAs, and investigate their roles as pivotal molecular regulators directing the long-lived phenotype. Mapping the signature miRNAs to the inversely expressed putative target genes, followed by in situ immunohistochemical staining and in vitro correlation assays, reveals that dwarf mice post-transcriptionally regulate key proteins of intermediate metabolism, most importantly the biosynthetic pathway involving ornithine decarboxylase and spermidine synthase. Functional assays using 3'-untranslated region reporter constructs in co-transfection experiments confirm that miRNA-27a indeed suppresses the expression of both of these proteins, marking them as probable targets of this miRNA in vivo. Moreover, the putative repressed action of this miRNA on ornithine decarboxylase is identified in dwarf mouse liver as early as 2 months of age. Taken together, our results show that among the altered aspects of intermediate metabolism detected in the dwarf mouse liver--glutathione metabolism, the urea cycle and polyamine biosynthesis--miRNA-27a is a key post-transcriptional control. Furthermore, compared to its normal siblings, the dwarf mouse exhibits a head start in regulating these pathways to control their normality, which may ultimately contribute to its extended health-span and longevity.

Effect of age and latent CMV infection on CD8+ CD56+ T cells (NKT-like) frequency and functionality.

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Hassouneh, Fakhri; Campos, Carmen; López-Sejas, Nelson; Alonso, Corona; Tarazona, Raquel; Solana, Rafael; Pera, Alejandra

2016-09-01

Changes in the T cell pool caused by CMV infection have been proposed to contribute to immunosenescence, but it has been postulated that CMV can also have some beneficial effects in young individuals improving the immune response to other pathogens. T cells expressing CD56 (NKT-like cells) are cytotoxic effector cells with a significant role in the immune response against cancer. We have studied how age and latent CMV infection affect the frequency of NKT-like cells (CD8+ CD56+ T cells) and their response to Staphylococcal Enterotoxin B (SEB) in the context of CMV and ageing. NKT-like cell percentage increases with the combination of both CMV and age. The response to SEB and the polyfunctional index of NKT-like cells also increase with age in CMV-seropositive individuals. In young individuals, CMV infection induces a shift on the polyfunctional profile of CD8+ CD56- T cells not observed on the NKT-like cells response. NKT-like cells expressing CD57 are expanded in CMV-seropositive individuals and are more polyfunctional than their CD57-  counterpart. In addition CD57- NKT-like cells are more polyfunctional than CD8+ CD56- CD57- T cells. The results support that the expansion of polyfunctional NKT-cells may have a beneficial effect on the immune response against pathogens. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Initiation of Antiviral B Cell Immunity Relies on Innate Signals from Spatially Positioned NKT Cells.

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Gaya, Mauro; Barral, Patricia; Burbage, Marianne; Aggarwal, Shweta; Montaner, Beatriz; Warren Navia, Andrew; Aid, Malika; Tsui, Carlson; Maldonado, Paula; Nair, Usha; Ghneim, Khader; Fallon, Padraic G; Sekaly, Rafick-Pierre; Barouch, Dan H; Shalek, Alex K; Bruckbauer, Andreas; Strid, Jessica; Batista, Facundo D

2018-01-25

B cells constitute an essential line of defense from pathogenic infections through the generation of class-switched antibody-secreting cells (ASCs) in germinal centers. Although this process is known to be regulated by follicular helper T (TfH) cells, the mechanism by which B cells initially seed germinal center reactions remains elusive. We found that NKT cells, a population of innate-like T lymphocytes, are critical for the induction of B cell immunity upon viral infection. The positioning of NKT cells at the interfollicular areas of lymph nodes facilitates both their direct priming by resident macrophages and the localized delivery of innate signals to antigen-experienced B cells. Indeed, NKT cells secrete an early wave of IL-4 and constitute up to 70% of the total IL-4-producing cells during the initial stages of infection. Importantly, the requirement of this innate immunity arm appears to be evolutionarily conserved because early NKT and IL-4 gene signatures also positively correlate with the levels of neutralizing antibodies in Zika-virus-infected macaques. In conclusion, our data support a model wherein a pre-TfH wave of IL-4 secreted by interfollicular NKT cells triggers the seeding of germinal center cells and serves as an innate link between viral infection and B cell immunity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Evaluation of the Role of Peroxisome Proliferator-Activated Receptor α (PPARα) in Mouse Liver Tumor Induction by Trichloroethylene and Metabolites

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Trichloroethylene (TCE) is an industrial solvent and a widespread environmental contaminant. Induction of liver cancer in mice by TCE is thought to be mediated by two metabolites, dichloroacetate (DCA) and trichloroacetate (TCA), both of which are themselves mouse liver carcinoge...

Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

Energy Technology Data Exchange (ETDEWEB)

Kazantseva, Yuliya A.; Yarushkin, Andrei A. [Institute of Molecular Biology and Biophysics SB RAMS, Novosibirsk, Timakova str., 2, 630117 (Russian Federation); Pustylnyak, Vladimir O., E-mail: pustylnyak@ngs.ru [Institute of Molecular Biology and Biophysics SB RAMS, Novosibirsk, Timakova str., 2, 630117 (Russian Federation); Novosibirsk State University, Novosibirsk, Pirogova str., 2, 630090 (Russian Federation)

2013-09-01

Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CAR and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their cell

Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

International Nuclear Information System (INIS)

Kazantseva, Yuliya A.; Yarushkin, Andrei A.; Pustylnyak, Vladimir O.

2013-01-01

Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CAR and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their cell

Fine tuning a well-oiled machine: Influence of NK1.1 and NKG2D on NKT cell development and function.

Science.gov (United States)

Joshi, Sunil K; Lang, Mark L

2013-10-01

Natural killer T cells (NKT) represent a group of CD1d-restricted T-lineage cells that provide a functional interface between innate and adaptive immune responses in infectious disease, cancer, allergy and autoimmunity. There have been remarkable advances in understanding the molecular events that underpin NKT development in the thymus and in the complex array of functions in the periphery. Most functional studies have focused on activation of T cell antigen receptors expressed by NKT cells and their responses to CD1d presentation of glycolipid and related antigens. Receiving less attention has been several molecules that are hallmarks of Natural Killer (NK) cells, but nonetheless expressed by NKT cells. These include several activating and inhibitory receptors that may fine-tune NKT development and survival, as well as activation via antigen receptors. Herein, we review the possible roles of the NK1.1 and NKG2D receptors in regulating development and function of NKT cells in health and disease. We suggest that pharmacological alteration of NKT activity should consider the potential complexities commensurate with NK1.1 and NKG2D expression. Published by Elsevier B.V.

Intravenous administration of stabilized antisense lipid particles (SALP) leads to activation and expansion of liver natural killer cells.

Science.gov (United States)

Bramson, J L; Bodner, C A; Johnson, J; Semple, S; Hope, M J

2000-06-01

Stabilized antisense lipid particles (SALP) have been developed for the systemic delivery of oligonucleotides. The impact of intravenous SALP administration was measured with respect to activation of natural killer (NK) and NK1.1+ T (NKT) cells in the livers of immunocompetent mice. Treatment with a SALP containing a highly mitogenic oligonucleotide (INX-6295) generated an increase in NK cytolytic activity and cell number within the liver but did not appear to affect the number of hepatic NKT cells or their cytolytic activity. The same results were observed after intravenous administration of the mitogenic oligonucleotide alone. Interestingly, treatment with a SALP containing a weakly mitogenic oligonucleotide (INX-6300) also activated the liver NK cells, whereas the oligonucleotide alone was unable to elicit these effects. The NK stimulatory activity of a SALP containing INX-6300 required both lipid and oligonucleotide components. These results demonstrate that in addition to modifying the pharmacokinetics and biodistribution of intravenously administered oligonucleotides, SALP possess immunostimulatory activity independent of oligonucleotide mitogenicity, which can serve as an adjuvant to antisense therapies for cancer.

Primary NK/T cell lymphoma nasal type of the stomach with skin involvement: a case report

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Sebastian Kobold

2009-12-01

Full Text Available Since nasal NK/T cell lymphoma and NK/T cell lymphoma nasal type are rare diseases, gastric involvement has seldom been seen. We report a unique case of a patient with a primary NK/T cell lymphoma nasal type of the stomach with skin involvement. The patient had no history of malignant diseases and was diagnosed with hematemesis and intense bleeding from his gastric primary site. Shortly after this event, exanthemic skin lesions appeared with concordant histology to the primary site. Despite chemotherapy, the patient died one month after the first symptomatic appearance of disease.

Cellular Adjuvant Properties, Direct Cytotoxicity of Re-differentiated Vα24 Invariant NKT-like Cells from Human Induced Pluripotent Stem Cells

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Shuichi Kitayama

2016-02-01

Full Text Available Vα24 invariant natural killer T (iNKT cells are a subset of T lymphocytes implicated in the regulation of broad immune responses. They recognize lipid antigens presented by CD1d on antigen-presenting cells and induce both innate and adaptive immune responses, which enhance effective immunity against cancer. Conversely, reduced iNKT cell numbers and function have been observed in many patients with cancer. To recover these numbers, we reprogrammed human iNKT cells to pluripotency and then re-differentiated them into regenerated iNKT cells in vitro through an IL-7/IL-15-based optimized cytokine combination. The re-differentiated iNKT cells showed proliferation and IFN-γ production in response to α-galactosylceramide, induced dendritic cell maturation and downstream activation of both cytotoxic T lymphocytes and NK cells, and exhibited NKG2D- and DNAM-1-mediated NK cell-like cytotoxicity against cancer cell lines. The immunological features of re-differentiated iNKT cells and their unlimited availability from induced pluripotent stem cells offer a potentially effective immunotherapy against cancer.

α-Lactose Improves the Survival of Septic Mice by Blockade of TIM-3 Signaling to Prevent NKT Cell Apoptosis and Attenuate Cytokine Storm.

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Yao, Yao; Deng, Hai; Li, Pingfei; Zhang, Jian; Zhang, Junbo; Wang, Deping; Li, Songbo; Luo, Yixing; Wei, Zhengping; Bi, Guoyu; Yang, Xiang-Ping; Tang, Zhao-Hui

2017-03-01

Sepsis is the leading cause of death among critically ill patients and natural killer T (NKT) cell activation is essential to induce inflammatory cytokine cascade in sepsis. However, little is known about what regulates the NKT cell function during sepsis. Herein, we showed that T-cell immunoglobulin and mucin domain 3 (Tim-3) expression in NKT cells is elevated in experimental mice during sepsis. Tim-3 expression was positively correlated with NKT cell activation and apoptosis. In sepsis, interleukin (IL)-12 secreted by dendritic cell exposure to lipopolysaccharide increased the expression of Tim-3 in NKT cells. Administration of α-lactose to block Tim-3 signaling pathway significantly improved the survival of septic mice, concomitant with reduced IL-12 production by dendritic cells, reduced Tim-3 expression, prevented NKT cell apoptosis, and attenuated production of inflammatory cytokines. Collectively, Tim-3 signaling in NKT cells plays a critical role in the immunopathogenesis of sepsis. Thus, α-lactose could be a promising immunomodulatory agent in the treatment of sepsis.

IL-10 Production Is Critical for Sustaining the Expansion of CD5+ B and NKT Cells and Restraining Autoantibody Production in Congenic Lupus-Prone Mice.

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Yuriy Baglaenko

Full Text Available The development and progression of systemic lupus erythematosus is mediated by the complex interaction of genetic and environmental factors. To decipher the genetics that contribute to pathogenesis and the production of pathogenic autoantibodies, our lab has focused on the generation of congenic lupus-prone mice derived from the New Zealand Black (NZB strain. Previous work has shown that an NZB-derived chromosome 4 interval spanning 32 to 151 Mb led to expansion of CD5+ B and Natural Killer T (NKT cells, and could suppress autoimmunity when crossed with a lupus-prone mouse strain. Subsequently, it was shown that CD5+ B cells but not NKT cells derived from these mice could suppress the development of pro-inflammatory T cells. In this paper, we aimed to further resolve the genetics that leads to expansion of these two innate-like populations through the creation of additional sub-congenic mice and to characterize the role of IL-10 in the suppression of autoimmunity through the generation of IL-10 knockout mice. We show that expansion of CD5+ B cells and NKT cells localizes to a chromosome 4 interval spanning 91 to 123 Mb, which is distinct from the region that mediates the majority of the suppressive phenotype. We also demonstrate that IL-10 is critical to restraining autoantibody production and surprisingly plays a vital role in supporting the expansion of innate-like populations.

IL-10 Production Is Critical for Sustaining the Expansion of CD5+ B and NKT Cells and Restraining Autoantibody Production in Congenic Lupus-Prone Mice.

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Baglaenko, Yuriy; Manion, Kieran P; Chang, Nan-Hua; Gracey, Eric; Loh, Christina; Wither, Joan E

2016-01-01

The development and progression of systemic lupus erythematosus is mediated by the complex interaction of genetic and environmental factors. To decipher the genetics that contribute to pathogenesis and the production of pathogenic autoantibodies, our lab has focused on the generation of congenic lupus-prone mice derived from the New Zealand Black (NZB) strain. Previous work has shown that an NZB-derived chromosome 4 interval spanning 32 to 151 Mb led to expansion of CD5+ B and Natural Killer T (NKT) cells, and could suppress autoimmunity when crossed with a lupus-prone mouse strain. Subsequently, it was shown that CD5+ B cells but not NKT cells derived from these mice could suppress the development of pro-inflammatory T cells. In this paper, we aimed to further resolve the genetics that leads to expansion of these two innate-like populations through the creation of additional sub-congenic mice and to characterize the role of IL-10 in the suppression of autoimmunity through the generation of IL-10 knockout mice. We show that expansion of CD5+ B cells and NKT cells localizes to a chromosome 4 interval spanning 91 to 123 Mb, which is distinct from the region that mediates the majority of the suppressive phenotype. We also demonstrate that IL-10 is critical to restraining autoantibody production and surprisingly plays a vital role in supporting the expansion of innate-like populations.

Polyclonal type II natural killer T cells require PLZF and SAP for their development and contribute to CpG-mediated antitumor response

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Zhao, Jie; Weng, Xiufang; Bagchi, Sreya; Wang, Chyung-Ru

2014-01-01

CD1d-restricted natural killer T (NKT) cells are innate-like T cells with potent immunomodulatory function via rapid production of both Th1 and Th2 cytokines. NKT cells comprise well-characterized type I NKT cells, which can be detected by α-galactosylceramide-loaded CD1d tetramers, and less-studied type II NKT cells, which do not recognize α-galactosylceramide. Here we characterized type II NKT cells on a polyclonal level by using a Jα18-deficient IL-4 reporter mouse model. This model allows us to track type II NTK cells by the GFP+TCRβ+ phenotype in the thymus and liver. We found type II NKT cells, like type I NKT cells, exhibit an activated phenotype and are dependent on the transcriptional regulator promyelocytic leukemia zinc finger (PLZF) and the adaptor molecule signaling lymphocyte activation molecule-associated protein (SAP) for their development. Type II NKT cells are potently activated by β-D-glucopyranosylceramide (β-GlcCer) but not sulfatide or phospholipids in a CD1d-dependent manner, with the stimulatory capacity of β-GlcCer influenced by acyl chain length. Compared with type I NKT cells, type II NKT cells produce lower levels of IFN-γ but comparable amounts of IL-13 in response to polyclonal T-cell receptor stimulation, suggesting they may play different roles in regulating immune responses. Furthermore, type II NKT cells can be activated by CpG oligodeoxynucletides to produce IFN-γ, but not IL-4 or IL-13. Importantly, CpG-activated type II NKT cells contribute to the antitumor effect of CpG in the B16 melanoma model. Taken together, our data reveal the characteristics of polyclonal type II NKT cells and their potential role in antitumor immunotherapy. PMID:24550295

Invariant NKT cells in adrenoleukodystrophy patients and mice

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Gautron, A. S.; Giquel, B.; Beaudoin, L.; Autrusseau, E.; Speak, A.; Platt, F.; Kemp, S.; Pujol, A.; Aubourg, P.; Lehuen, A.

2010-01-01

X-linked adrenoleukodystrophy (X-ALD) is a severe neurological disease characterized by progressive demyelination within the CNS, adrenal insufficiency, and is associated with an accumulation of saturated very long chain fatty acids in plasma and tissues of patients. iNKT cells, a distinct lineage

Promiscuous activity of the LXR antagonist GSK2033 in a mouse model of fatty liver disease

International Nuclear Information System (INIS)

Griffett, Kristine; Burris, Thomas P.

2016-01-01

The liver X receptor (LXR) functions as a receptor for oxysterols and plays a critical role in the regulation of glucose and lipid metabolism. We recently described a synthetic LXR inverse agonist that displayed efficacy in treatment of hepatic steatosis in a mouse model of non-alcoholic fatty liver disease (NAFLD). This compound, SR9238, was designed to display liver specificity so as to avoid potential detrimental effects on reverse cholesterol transport in peripheral tissues. Here, we examined the effects of a LXR antagonist/inverse agonist, GSK2033, which displays systemic exposure. Although GSK2033 performed as expected in cell-based models as a LXR inverse agonist, it displayed unexpected activity in the mouse NAFLD model. The expression of lipogenic enzyme genes such as fatty acid synthase and sterol regulatory binding protein 1c were induced rather than suppressed and no effect on hepatic steatosis was found. Further characterization of the specificity of GSK2033 revealed that it displayed a significant degree of promiscuity, targeting a number of other nuclear receptors that could clearly alter hepatic gene expression. - Highlights: • The LXR antagonist GSK2033 suppresses the expression of lipogenic genes FASN and SREBF1 in HepG2 cells. • GSK2033 exhibits sufficient exposure to perform animal experiments targeting the liver. • GSK2033 has fails to suppress hepatic Fasn and Srebf1 expression in an animal model of non-alcoholic fatty liver disease. • GSK2033 may regulate the activity of several nuclear receptors.

Transfer of mRNA Encoding Invariant NKT Cell Receptors Imparts Glycolipid Specific Responses to T Cells and γδT Cells.

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Shimizu, Kanako; Shinga, Jun; Yamasaki, Satoru; Kawamura, Masami; Dörrie, Jan; Schaft, Niels; Sato, Yusuke; Iyoda, Tomonori; Fujii, Shin-Ichiro

2015-01-01

Cell-based therapies using genetically engineered lymphocytes expressing antigen-specific T cell receptors (TCRs) hold promise for the treatment of several types of cancers. Almost all studies using this modality have focused on transfer of TCR from CD8 cytotoxic T lymphocytes (CTLs). The transfer of TCR from innate lymphocytes to other lymphocytes has not been studied. In the current study, innate and adaptive lymphocytes were transfected with the human NKT cell-derived TCRα and β chain mRNA (the Vα24 and Vβ11 TCR chains). When primary T cells transfected with NKT cell-derived TCR were subsequently stimulated with the NKT ligand, α-galactosylceramide (α-GalCer), they secreted IFN-γ in a ligand-specific manner. Furthermore when γδT cells were transfected with NKT cell-derived TCR mRNA, they demonstrated enhanced proliferation, IFN-γ production and antitumor effects after α-GalCer stimulation as compared to parental γδT cells. Importantly, NKT cell TCR-transfected γδT cells responded to both NKT cell and γδT cell ligands, rendering them bi-potential innate lymphocytes. Because NKT cell receptors are unique and universal invariant receptors in humans, the TCR chains do not yield mispaired receptors with endogenous TCR α and β chains after the transfection. The transfection of NKT cell TCR has the potential to be a new approach to tumor immunotherapy in patients with various types of cancer.

Differential inhibitory and activating NK cell receptor levels and NK/NKT-like cell functionality in chronic and recovered stages of chikungunya.

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Thanapati, Subrat; Ganu, Mohini A; Tripathy, Anuradha S

2017-01-01

The role of natural killer (NK; CD3-CD56+)/NKT (CD3+CD56+)-like cells in chikungunya virus (CHIKV) disease progression/recovery remains unclear. Here, we investigated the expression profiles and function of NK and NKT-like cells from 35 chronic chikungunya patients, 30 recovered individuals, and 69 controls. Percentage of NKT-like cells was low in chronic chikungunya patients. NKp30+, CD244+, DNAM-1+, and NKG2D+ NK cell percentages were also lower (MFI and/or percentage), while those of CD94+ and NKG2A+ NKT-like cells were higher (MFI and/or percentage) in chronic patients than in recovered subjects. IFN-γ and TNF-α expression on NKT-like cells was high in the chronic patients, while only IFN-γ expression on NK cells was high in the recovered individuals. Furthermore, percentage of perforin+NK cells was low in the chronic patients. Lower cytotoxic activity was observed in the chronic patients than in the controls. CD107a expression on NK and NKT-like cells post anti-CD94/anti-NKG2A blocking was comparable among the patients and controls. Upregulated inhibitory and downregulated activating NK receptor expressions on NK/NKT-like cells, lower perforin+ and CD107a+NK cells are likely responsible for inhibiting the NK and NKT-like cell function in the chronic stage of chikungunya. Therefore, deregulation of NKR expression might underlie CHIKV-induced chronicity.

The immunoregulatory role of type I and type II NKT cells in cancer and other diseases

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Terabe, Masaki; Berzofsky, Jay A.

2014-01-01

NKT cells are CD1d-restricted T cells that recognize lipid antigens. They also have been shown to play critical roles in the regulation of immune responses. In the immune responses against tumors, two subsets of NKT cells, type I and type II, play opposing roles and cross-regulate each other. As members of both the innate and adaptive immune systems, which form a network of multiple components, they also interact with other immune components. Here we discuss the function of NKT cells in tumor immunity and their interaction with other regulatory cells, especially CD4+CD25+Foxp3+ regulatory T cells. PMID:24384834

Hepatoprotective Effects of Antrodia cinnamomea: The Modulation of Oxidative Stress Signaling in a Mouse Model of Alcohol-Induced Acute Liver Injury

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Yange Liu

2017-01-01

Full Text Available In the present study, the components of A. cinnamomea (AC mycelia were systematically analyzed. Subsequently, its hepatoprotective effects and the underlying mechanisms were explored using a mouse model of acute alcohol-induced liver injury. AC contained 25 types of fatty acid, 16 types of amino acid, 3 types of nucleotide, and 8 types of mineral. The hepatoprotective effects were observed after 2 weeks of AC treatment at doses of 75 mg/kg, 225 mg/kg, and 675 mg/kg in the mouse model. These effects were indicated by the changes in the levels of aspartate aminotransferase, alanine aminotransferase, several oxidation-related factors, and inflammatory cytokines in serum and/or liver samples. AC reduced the incidence rate of necrosis, inflammatory infiltration, fatty droplets formation, and cell apoptosis in liver detecting via histological and TUNEL assay. In addition, AC reduced the expression of cleaved caspase-3, -8, and -9 and the levels of phosphor-protein kinase B (Akt and phosphor-nuclear factor-κB (NF-κB in the liver samples. Collectively, AC-mediated hepatoprotective effects in a mouse model of acute alcohol-induced liver injury are the result of reduction in oxidative stress. This may be associated with Akt/NF-κB signaling. These results provide valuable evidence to support the use of A. cinnamomea as a functional food and/or medicine.

Toxicogenomic Dissection of the Perfluorooctanoic Acid Transcript Profile in Mouse Liver: Evidence for Involvement of the Nuclear Receptors PPARα and CAR

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A number of perfluorinated alkyl acids including perfluorooctanoic acid (PFOA) elicit effects similar to peroxisome proliferator chemicals (PPC) in mouse and rat liver. There is strong evidence that PPC cause many of their effects related to liver carcinogenesis through the nucle...

Dendritic cells and anergic type I NKT cells play a crucial role in sulfatide-mediated immune regulation in experimental autoimmune encephalomyelitis.

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Maricic, Igor; Halder, Ramesh; Bischof, Felix; Kumar, Vipin

2014-08-01

CD1d-restricted NKT cells can be divided into two groups: type I NKT cells use a semi-invariant TCR, whereas type II express a relatively diverse set of TCRs. A major subset of type II NKT cells recognizes myelin-derived sulfatides and is selectively enriched in the CNS tissue during experimental autoimmune encephalomyelitis (EAE). We have shown that activation of sulfatide-reactive type II NKT cells by sulfatide prevents induction of EAE. In this article, we have addressed the mechanism of regulation, as well as whether a single immunodominant form of synthetic sulfatide can treat ongoing chronic and relapsing EAE in SJL/J mice. We have shown that the activation of sulfatide-reactive type II NKT cells leads to a significant reduction in the frequency and effector function of myelin proteolipid proteins 139-151/I-A(s)-tetramer(+) cells in lymphoid and CNS tissues. In addition, type I NKT cells and dendritic cells (DCs) in the periphery, as well as CNS-resident microglia, are inactivated after sulfatide administration, and mice deficient in type I NKT cells are not protected from disease. Moreover, tolerized DCs from sulfatide-treated animals can adoptively transfer protection into naive mice. Treatment of SJL/J mice with a synthetic cis-tetracosenoyl sulfatide, but not α-galactosylceramide, reverses ongoing chronic and relapsing EAE. Our data highlight a novel immune-regulatory pathway involving NKT subset interactions leading to inactivation of type I NKT cells, DCs, and microglial cells in suppression of autoimmunity. Because CD1 molecules are nonpolymorphic, the sulfatide-mediated immune-regulatory pathway can be targeted for development of non-HLA-dependent therapeutic approaches to T cell-mediated autoimmune diseases. Copyright © 2014 by The American Association of Immunologists, Inc.

Overexpression of the long noncoding RNA TUG1 protects against cold-induced injury of mouse livers by inhibiting apoptosis and inflammation.

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Su, Song; Liu, Jiang; He, Kai; Zhang, Mengyu; Feng, Chunhong; Peng, Fangyi; Li, Bo; Xia, Xianming

2016-04-01

Hepatic injury provoked by cold storage is a major problem affecting liver transplantation, as exposure to cold induces apoptosis in hepatic tissues. Long noncoding RNAs (lncRNAs) are increasingly understood to regulate apoptosis, but the contribution of lncRNAs to cold-induced liver injury remains unknown. Using RNA-seq, we determined the differential lncRNA expression profile in mouse livers after cold storage and found that expression of the lncRNA TUG1 was significantly down-regulated. Overexpression of TUG1 attenuated cold-induced apoptosis in mouse hepatocytes and liver sinusoidal endothelial cells LSECs, in part by blocking mitochondrial apoptosis and endoplasmic reticulum (ER) stress pathways. Moreover, TUG1 attenuated apoptosis, inflammation, and oxidative stress in vivo in livers subjected to cold storage. Overexpression of TUG1 also improved hepatocyte function and prolonged hepatic graft survival rates in mice. These results suggest that the lncRNA TUG1 exerts a protective effect against cold-induced liver damage by inhibiting apoptosis in mice, and suggests a potential role for TUG1 as a target for the prevention of cold-induced liver damage in liver transplantation. RNA-seq data are available from GEO using accession number GSE76609. © 2016 Federation of European Biochemical Societies.

The Extended Family of CD1d-Restricted NKT Cells: Sifting through a Mixed Bag of TCRs, Antigens, and Functions.

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Macho-Fernandez, Elodie; Brigl, Manfred

2015-01-01

Natural killer T (NKT) cells comprise a family of specialized T cells that recognize lipid antigens presented by CD1d. Based on their T cell receptor (TCR) usage and antigen specificities, CD1d-restricted NKT cells have been divided into two main subsets: type I NKT cells that use a canonical invariant TCR α-chain and recognize α-galactosylceramide (α-GalCer), and type II NKT cells that use a more diverse αβ TCR repertoire and do not recognize α-GalCer. In addition, α-GalCer-reactive NKT cells that use non-canonical αβ TCRs and CD1d-restricted T cells that use γδ or δ/αβ TCRs have recently been identified, revealing further diversity among CD1d-restricted T cells. Importantly, in addition to their distinct antigen specificities, functional differences are beginning to emerge between the different members of the CD1d-restricted T cell family. In this review, while using type I NKT cells as comparison, we will focus on type II NKT cells and the other non-invariant CD1d-restricted T cell subsets, and discuss our current understanding of the antigens they recognize, the formation of stimulatory CD1d/antigen complexes, the modes of TCR-mediated antigen recognition, and the mechanisms and consequences of their activation that underlie their function in antimicrobial responses, anti-tumor immunity, and autoimmunity.

Toxicogenomic Dissection of the Perfluorooctanoic Acid Transcript Profile in Mouse Liver: Evidence for the Involvement of Nuclear Receptors PPARα and CAR

Science.gov (United States)

A number of perfluorinated alkyl acids including perfluorooctanoic acid (PFOA) elicit effects similar to peroxisome proliferator chemicals (PPC) in mouse and rat liver. There is strong evidence that PPC cause many of their effects linked to liver cancer through the nuclear recep...

Imaging of pharmacokinetic rates of indocyanine green in mouse liver with a hybrid fluorescence molecular tomography/x-ray computed tomography system.

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Zhang, Guanglei; Liu, Fei; Zhang, Bin; He, Yun; Luo, Jianwen; Bai, Jing

2013-04-01

Pharmacokinetic rates have the potential to provide quantitative physiological and pathological information for biological studies and drug development. Fluorescence molecular tomography (FMT) is an attractive imaging tool for three-dimensionally resolving fluorophore distribution in small animals. In this letter, pharmacokinetic rates of indocyanine green (ICG) in mouse liver are imaged with a hybrid FMT and x-ray computed tomography (XCT) system. A recently developed FMT method using structural priors from an XCT system is adopted to improve the quality of FMT reconstruction. In the in vivo experiments, images of uptake and excretion rates of ICG in mouse liver are obtained, which can be used to quantitatively evaluate liver function. The accuracy of the results is validated by a fiber-based fluorescence measurement system.

The Prognostic Impact of NK/NKT Cell Density in Periampullary Adenocarcinoma Differs by Morphological Type and Adjuvant Treatment.

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Lundgren, Sebastian; Warfvinge, Carl Fredrik; Elebro, Jacob; Heby, Margareta; Nodin, Björn; Krzyzanowska, Agnieszka; Bjartell, Anders; Leandersson, Karin; Eberhard, Jakob; Jirström, Karin

2016-01-01

Natural killer (NK) cells and NK T cells (NKT) are vital parts of tumour immunosurveillance. However, their impact on prognosis and chemotherapy response in periampullary adenocarcinoma, including pancreatic cancer, has not yet been described. Immune cell-specific expression of CD56, CD3, CD68 and CD1a was analysed by immunohistochemistry on tissue microarrays with tumours from 175 consecutive cases of periampullary adenocarcinoma, 110 of pancreatobiliary type (PB-type) and 65 of intestinal type (I-type) morphology. Kaplan-Meier and Cox regression analysis were applied to determine the impact of CD56+ NK/NKT cells on 5-year overall survival (OS). High density of CD56+ NK/NKT cells correlated with low N-stage and lack of perineural, lymphatic vessel and peripancreatic fat invasion. High density of CD56+ NK/NKT cells was associated with prolonged OS in Kaplan-Meier analysis (p = 0.003), and in adjusted Cox regression analysis (HR = 0.49; 95% CI 0.29-0.86). The prognostic effect of high CD56+ NK/NKT cell infiltration was only evident in cases not receiving adjuvant chemotherapy in PB-type tumours (p for interaction = 0.014). This study demonstrates that abundant infiltration of CD56+ NK/NKT cells is associated with a prolonged survival in periampullary adenocarcinoma. However, the negative interaction with adjuvant treatment is noteworthy. NK cell enhancing strategies may prove to be successful in the management of these cancers.

Design of a potent CD1d-binding NKT cell ligand as a vaccine adjuvant.

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Li, Xiangming; Fujio, Masakazu; Imamura, Masakazu; Wu, Douglass; Vasan, Sandhya; Wong, Chi-Huey; Ho, David D; Tsuji, Moriya

2010-07-20

The glycolipid alpha-galactosylceramide (alpha-GalCer) has been shown to bind CD1d molecules to activate invariant natural killer T (iNKT) cells, and subsequently induce activation of various immune-competent cells, including dendritic cells, thereby providing a significant adjuvant effect for various vaccines. However, in phase I clinical trials, alpha-GalCer was shown to display only marginal biological activity. In our search for a glycolipid that can exert more potent stimulatory activity against iNKT cells and dendritic cells and produce an adjuvant effect superior to alpha-GalCer, we performed step-wise screening assays on a focused library of 25 alpha-GalCer analogues. Assays included quantification of the magnitude of stimulatory activity against human iNKT cells in vitro, binding affinity to human and murine CD1d molecules, and binding affinity to the invariant t cell receptor of human iNKT cells. Through this rigorous and iterative screening process, we have identified a lead candidate glycolipid, 7DW8-5, that exhibits a superior adjuvant effect than alpha-GalCer on HIV and malaria vaccines in mice.

Amelioration of radiation induced decrease in activity of catalase and superoxide dismutase in mouse liver by Punica granatum

International Nuclear Information System (INIS)

Sharma, Jaimala; Mathur, Aarti

2013-01-01

Ionizing radiation generates reactive oxygen species (ROS) in irradiated tissue. Cells of liver have their own defence system, the antioxidant system to deactivate ROS. Antioxidant system includes enzymatic and non-enzymatic components. Liver is rich in endogenous antioxidants and related enzymes. Catalase and Superoxide dismutase (SOD) are powerful antioxidant enzymes. In the present study Punica granatum fruit rind Ethanol extract (PGFRE) was tested against 60 Co gamma radiation induced alteration in Swiss albino mouse. Healthy adult (25±2) Swiss albino mouse were selected and divided into four groups. The first group was sham irradiated. The second group was irradiated with 8 Gy 60 Co gamma radiation only and served as control. The third group was administered with Ethanol extract of Punica granatum fruit rind one hour before irradiation at the dose rate of 10 mg/kg body weight orally. Animals were exposed to 8 Gy 60 Co gamma radiation. Fourth group was administered with Ethanol extract of Punica granatum fruit rind at the dose rate of 10 mg/kg body weight. Mice were sacrificed at various post irradiation intervals and liver was removed, weighed and analysed biochemically for Catalase and SOD activity. Catalase and SOD activity decreased up till 7th post irradiation day in 8 Gy irradiated group than normal. In PGFRE pretreated irradiated group catalase and SOD activity were higher than the corresponding control group at all the intervals. These results indicate that PGFRE extract protects damage to the catalase and SOD activity in liver of Swiss albino mouse against lethal dose of gamma radiation. (author)

Selective decrease in circulating V alpha 24+V beta 11+ NKT cells during HIV type 1 infection

NARCIS (Netherlands)

van der Vliet, Hans J. J.; von Blomberg, B. Mary E.; Hazenberg, Mette D.; Nishi, Nobusuke; Otto, Sigrid A.; van Benthem, Birgit H.; Prins, Maria; Claessen, Frans A.; van den Eertwegh, Alfons J. M.; Giaccone, Giuseppe; Miedema, Frank; Scheper, Rik J.; Pinedo, Herbert M.

2002-01-01

CD1d-restricted NKT cells express an invariant TCR and have been demonstrated to play an important regulatory role in a variety of immune responses. Invariant NKT cells down-regulate autoimmune responses by production of type 2 cytokines and can initiate antitumor and antimicrobial immune responses

Effect of adeturone on the concentration of endogenous sulfhydryl groups in mouse spleen and liver

International Nuclear Information System (INIS)

Pantev, T.; Bychvarova, K.

1981-01-01

Levels of endogenous sulfhydryl groups (total, protein, and non-protein) in mouse liver and spleen were studied for response to the radioprotective drug Adeturone (AET adenosine triphosphate) as recorded at various time intervals (5 - 90 min) following administration of a 300 mg/kg b.w. dose. Spleen sulfhydryl concentration levels tended to elevation, with the peak effect noted at 45 min post-treatment. In the liver, augmentation was observed only for non-protein sylfhydryl groups, at 10 and 15 min post-treatment (time intervals when Adeturone affords maximum protection against radiation); at the 60 min, however, there was a statistically reliable drop. The findings indicate that Adeturone treatment produces response patterns of opposite directions in liver and spleen endogenous thiols. (A.B.)

Completion of hepatitis C virus replication cycle in heterokaryons excludes dominant restrictions in human non-liver and mouse liver cell lines.

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Anne Frentzen

2011-04-01

Full Text Available Hepatitis C virus (HCV is hepatotropic and only infects humans and chimpanzees. Consequently, an immunocompetent small animal model is lacking. The restricted tropism of HCV likely reflects specific host factor requirements. We investigated if dominant restriction factors expressed in non-liver or non-human cell lines inhibit HCV propagation thus rendering these cells non-permissive. To this end we explored if HCV completes its replication cycle in heterokaryons between human liver cell lines and non-permissive cell lines from human non-liver or mouse liver origin. Despite functional viral pattern recognition pathways and responsiveness to interferon, virus production was observed in all fused cells and was only ablated when cells were treated with exogenous interferon. These results exclude that constitutive or virus-induced expression of dominant restriction factors prevents propagation of HCV in these cell types, which has important implications for HCV tissue and species tropism. In turn, these data strongly advocate transgenic approaches of crucial human HCV cofactors to establish an immunocompetent small animal model.

Heterogenic transplantation of bone marrow-derived rhesus macaque mesenchymal stem cells ameliorates liver fibrosis induced by carbon tetrachloride in mouse

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Xufeng Fu

2018-02-01

Full Text Available Liver fibrosis is a disease that causes high morbidity and has become a major health problem. Liver fibrosis can lead to the end stage of liver diseases (livercirrhosisand hepatocellularcarcinoma. Currently, liver transplantation is the only effective treatment for end-stage liver disease. However, the shortage of organ donors, high cost of medical surgery, immunological rejection and transplantation complications severely hamper liver transplantation therapy. Mesenchymal stem cells (MSCs have been regarded as promising cells for clinical applications in stem cell therapy in the treatment of liver diseases due to their unique multipotent differentiation capacity, immunoregulation and paracrine effects. Although liver fibrosis improvements by MSC transplantation in preclinical experiments as well as clinical trials have been reported, the in vivo fate of MSCs after transportation and their therapeutic mechanisms remain unclear. In this present study, we isolated MSCs from the bone marrow of rhesus macaques. The cells exhibited typical MSC markers and could differentiate into chondrocytes, osteocytes, and adipocytes, which were not affected by labeling with enhanced green fluorescent protein (EGFP. The harvested MSCs respond to interferon-γ stimulation and have the ability to inhibit lymphocyte proliferation in vitro. EGFP-labeled MSCs (1 × 106 cells were transplanted into mice with carbon tetrachloride-induced liver fibrosis via tail vein injection. The ability of the heterogenic MSC infusion to ameliorate liver fibrosis in mice was evaluated by a blood plasma chemistry index, pathological examination and liver fibrosis-associated gene expression. Additionally, a small number of MSCs that homed and engrafted in the mouse liver tissues were evaluated by immunofluorescence analysis. Our results showed that the transplantation of heterogenic MSCs derived from monkey bone marrow can be used to treat liver fibrosis in the mouse model and that the

Human invariant NKT cell subsets differentially promote differentiation, antibody production, and T cell stimulation by B cells in vitro.

OpenAIRE

O'REILLY, VINCENT

2013-01-01

PUBLISHED Invariant NK T (iNKT) cells can provide help for B cell activation and Ab production. Because B cells are also capable of cytokine production, Ag presentation, and T cell activation, we hypothesized that iNKT cells will also influence these activities. Furthermore, subsets of iNKT cells based on CD4 and CD8 expression that have distinct functional activities may differentially affect B cell functions. We investigated the effects of coculturing expanded human CD4(+), CD8α(+), and ...

Increased expressions of NKp44, NKp46 on NK/NKT-like cells are associated with impaired cytolytic function in self-limiting hepatitis E infection.

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Das, Rumki; Tripathy, Anuradha

2014-10-01

We have characterized the NK/NKT-like cells in patients with self-limiting hepatitis E infection. The distribution of peripheral NK/NKT-like cells, expressions of activation receptors, cytotoxic potential and effector function of NK/NKT-like cells from fresh peripheral blood mononuclear cells of 86 acute patients, 101 recovered and 54 control individuals were assessed. Activated NKT-like (CD16(+) CD56(+) CD3(+)) cells were high in the patient groups. On CD56(+) CD3(-) cells, NKp44 and NKp46 expressions were high in the acute patients, whereas NKp30, NKp44, NKp46 and NKG2D were high in the recovered individuals. On CD56(+) CD3(+) cells, NKp44, NKp46 and NKG2D expressions were high in the recovered but NKp30 was low in both the patient groups. Collectively, the current study elucidates the role of NK/NKT-like cells demonstrating phenotypic alterations of activated NKT-like cells and activation receptors, lack of CD107a expression and functional impairment of peripheral NK/NKT-like cells in self-limiting hepatitis E infection.

[Detection of NK and NKT cells in peripheral blood of patients with cGVHD and its significance].

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Zhou, Mao-Hua; Wang, Chun-Miao; Gong, Cai-Ping; Luo, Yin; Zhang, Min

2012-10-01

The aim of this study was to investigate the correlation of NK and NKT cells in peripheral blood of patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) with chronic graft-versus-host disease (cGVHD). 64 patients undergoing allo-HSCT in Guangdong Provincial People Hospital were studied retrospectively. Among 64 cases, 21 cases were did not develop with cGVHD, 43 cases (mild 15, moderate 18, severe 10) were recorded with cGVHD. The frequency of NK and NKT cells in peripheral blood of patients were measured by flow cytometry. The counts of NK and NKT cells were measured by automatic five sort hematology cyto-analyser (LH-750). The frequency and counts of NK and NKT cells between patients with non-cGVHD and patients with different status of cGVHD were analysed. The results indicated that as compared with the non-cGVHD patients, the frequency and counts of NK cells in patients with cGVHD obviously reduced (P NKT cells were did not changed significantly. The frequency and counts of NK cells gradually decreased within the different status of cGVHD, the frequency and counts of NK cells in severe-cGVHD were significantly lower than that in mild-cGVHD. It is concluded that NK cells may play an important role in the incidence and development of cGVHD. The detection of frequency and counts of NK cells should be helpful to early diagnose cGVHD and provide valuable clues for assessing the severity of illnesses. NKT cells may have little effect on the incidence and development of cGVHD.

Cancer chemoprevention by ginseng in mouse liver and other organs.

Science.gov (United States)

Nishino, H; Tokuda, H; Ii, T; Takemura, M; Kuchide, M; Kanazawa, M; Mou, X Y; Bu, P; Takayasu, J; Onozuka, M; Masuda, M; Satomi, Y; Konoshima, T; Kishi, N; Baba, M; Okada, Y; Okuyama, T

2001-01-01

Oral administration of red ginseng extracts (1% in diet for 40 weeks) resulted in the significant suppression of spontaneous liver tumor formation in C3H/He male mice. Average number of tumors per mouse in control group was 1.06, while that in red ginseng extracts-treated group was 0.33 (p<0.05). Incidence of liver tumor development was also lower in red ginseng extracts-treated group, although the difference from control group was not statistically significant. Anti-carcinogenic activity of white ginseng extracts, besides red ginseng extracts, was also investigated. In the present study, the administration of white ginseng extracts was proven to suppress tumor promoter-induced phenomena in vitro and in vivo. It is of interest that oral administration of the extracts of Ren-Shen-Yang- Rong-Tang, a white ginseng-containing Chinese medicinal prescription, resulted in the suppression of skin tumor promotion by 12-o-tetradecanoylphorbol-13-acetate in 7,12-dimethylbenz[a]anthracene-initiated CD-1 mice. These results suggest the usefulness of ginseng in the field of cancer prevention. PMID:11748379

Differential requirement for the CD45 splicing regulator hnRNPLL for accumulation of NKT and conventional T cells.

Directory of Open Access Journals (Sweden)

Mehmet Yabas

Full Text Available Natural killer T (NKT cells represent an important regulatory T cell subset that develops in the thymus and contains immature (NK1.1(lo and mature (NK1.1(hi cell subsets. Here we show in mice that an inherited mutation in heterogeneous ribonucleoprotein L-like protein (hnRNPLL(thunder, that shortens the survival of conventional T cells, has no discernible effect on NKT cell development, homeostasis or effector function. Thus, Hnrpll deficiency effectively increases the NKT∶T cell ratio in the periphery. However, Hnrpll mutation disrupts CD45RA, RB and RC exon silencing of the Ptprc mRNA in both NKT and conventional T cells, and leads to a comparably dramatic shift to high molecular weight CD45 isoforms. In addition, Hnrpll mutation has a cell intrinsic effect on the expression of the developmentally regulated cell surface marker NK1.1 on NKT cells in the thymus and periphery but does not affect cell numbers. Therefore our results highlight both overlapping and divergent roles for hnRNPLL between conventional T cells and NKT cells. In both cell subsets it is required as a trans-acting factor to regulate alternative splicing of the Ptprc mRNA, but it is only required for survival of conventional T cells.

The comparison of lipid profiling in mouse brain and liver after starvation and a high-fat diet: A medical systems biology approach

NARCIS (Netherlands)

Ginneken, V.J.T. van; Verheij, E.; Hekman, M.; Greef, J. van der; Feskens, E.J.M.; Poelmann, R.E.

2011-01-01

We investigated with LC-MS techniques, measuring approximately 109 lipid compounds, in mouse brain and liver tissue after 48 hours of starvation and a High-Fat Diet if brain and liver lipid composition changed. We measured Cholesterolesters (ChE), Lysophosphatidyl-cholines (LPC), Phosphatidylcholine

Differential Recognition of CD1d-[alpha]-Galactosyl Ceramide by the V[beta]8.2 and V[beta]7 Semi-invariant NKT T Cell Receptors

Energy Technology Data Exchange (ETDEWEB)

Pellicci, Daniel G.; Patel, Onisha; Kjer-Nielsen, Lars; Pang, Siew Siew; Sullivan, Lucy C.; Kyparissoudis, Konstantinos; Brooks, Andrew G.; Reid, Hugh H.; Gras, Stephanie; Lucet, Isabelle S.; Koh, Ruide; Smyth, Mark J.; Mallevaey, Thierry; Matsuda, Jennifer L.; Gapin, Laurent; McCluskey, James; Godfrey, Dale I.; Rossjohn, Jamie; PMCI-A; Monash; UCHSC; Melbourne

2009-09-02

The semi-invariant natural killer T cell receptor (NKT TCR) recognizes CD1d-lipid antigens. Although the TCR{alpha} chain is typically invariant, the {beta} chain expression is more diverse, where three V{beta} chains are commonly expressed in mice. We report the structures of V{alpha}14-V{beta}8.2 and V{alpha}14-V{beta}7 NKT TCRs in complex with CD1d-{alpha}-galactosylceramide ({alpha}-GalCer) and the 2.5 {angstrom} structure of the human NKT TCR-CD1d-{alpha}-GalCer complex. Both V{beta}8.2 and V{beta}7 NKT TCRs and the human NKT TCR ligated CD1d-{alpha}-GalCer in a similar manner, highlighting the evolutionarily conserved interaction. However, differences within the V{beta} domains of the V{beta}8.2 and V{beta}7 NKT TCR-CD1d complexes resulted in altered TCR{beta}-CD1d-mediated contacts and modulated recognition mediated by the invariant {alpha} chain. Mutagenesis studies revealed the differing contributions of V{beta}8.2 and V{beta}7 residues within the CDR2{beta} loop in mediating contacts with CD1d. Collectively we provide a structural basis for the differential NKT TCR V{beta} usage in NKT cells.

Immune modulating effects of NKT cells in a physiologically low dose Leishmania major infection model after αGalCer analog PBS57 stimulation.

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Griewank, Klaus G; Lorenz, Beate; Fischer, Michael R; Boon, Louis; Lopez Kostka, Susanna; von Stebut, Esther

2014-06-01

Leishmaniasis is a parasitic infection affecting ∼12 million people worldwide, mostly in developing countries. Treatment options are limited and no effective vaccines exist to date. Natural Killer T (NKT) cells are a conserved innate-like lymphocyte population with immunomodulating effects in various settings. A number of reports state a role of NKT cells in different models of Leishmania infection. Here, we investigated the effect of NKT cells in a physiologically relevant, intradermal low dose infection model. After inoculation of 103 infectious-stage L. major, comparable numbers of skin-immigrating NKT cells in both susceptible BALB/c mice and resistant C57BL/6 mice were noted. Compared to their wild type counterparts, NKT cell-deficient mice on a C57BL/6 background were better able to contain infection with L. major and showed decreased IL-4 production in cytokine analysis performed 5 and 8 weeks after infection. Low doses of the NKT cell stimulating αGalCer analog PBS57 applied at the time of infection led to disease exacerbation in C57BL/6 wild-type, but not NKT-deficient mice. The effect was dependent both on the timing and amount of PBS57 administered. The effect of NKT cell stimulation by PBS57 proved to be IL-4 dependent, as it was neutralized in IL-4-deficient C57BL/6 or anti-IL-4 antibody-treated wild-type mice. In contrast to C57BL/6 mice, administration of PBS57 in susceptible BALB/c mice resulted in an improved course of disease. Our results reveal a strain- and cytokine-dependent regulatory role of NKT cells in the development of immunity to low dose L. major infections. These effects, probably masked in previous studies using higher parasite inocula, should be considered in future therapy and immunization approaches.

Development of Short-term Molecular Thresholds to Predict Long-term Mouse Liver Tumor Outcomes: Phthalate Case Study

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Short-term molecular profiles are a central component of strategies to model health effects of environmental chemicals. In this study, a 7 day mouse assay was used to evaluate transcriptomic and proliferative responses in the liver for a hepatocarcinogenic phthalate, di (2-ethylh...

PPARα activation differently affects microparticle content in atherosclerotic lesions and liver of a mouse model of atherosclerosis and NASH.

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Baron, Morgane; Leroyer, Aurélie S; Majd, Zouher; Lalloyer, Fanny; Vallez, Emmanuelle; Bantubungi, Kadiombo; Chinetti-Gbaguidi, Giulia; Delerive, Philippe; Boulanger, Chantal M; Staels, Bart; Tailleux, Anne

2011-09-01

Atherosclerosis and non-alcoholic fatty liver disease (NAFLD) are complex pathologies characterized by lipid accumulation, chronic inflammation and extensive tissue remodelling. Microparticles (MPs), small membrane vesicles produced by activated and apoptotic cells, might not only be biomarkers, but also functional actors in these pathologies. The apoE2-KI mouse is a model of atherosclerosis and NAFLD. Activation of the nuclear receptor PPARα decreases atherosclerosis and components of non-alcoholic steatohepatitis (NASH) in the apoE2-KI mouse. (1) To determine whether MPs are present in atherosclerotic lesions, liver and plasma during atherosclerosis and NASH progression in apoE2-KI mice, and (2) to study whether PPARα activation modulates MP concentrations. ApoE2-KI mice were fed a Western diet to induce atherosclerosis and NASH. MPs were isolated from atherosclerotic lesions, liver and blood and quantified by flow cytometry. An increase of MPs was observed in the atherosclerotic lesions and in the liver of apoE2-KI mice upon Western diet feeding. PPARα activation with fenofibrate decreased MP levels in the atherosclerotic lesions in a PPARα-dependent manner, but did not influence MP concentrations in the liver. Here we report that MPs are present in atherosclerotic lesions and in the liver of apoE2-KI mice. Their concentration increased during atherosclerosis and NASH development. PPARα activation differentially modulates MP levels in a tissue-specific manner. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Clinical development of a novel CD1d-binding NKT cell ligand as a vaccine adjuvant.

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Padte, Neal N; Li, Xiangming; Tsuji, Moriya; Vasan, Sandhya

2011-08-01

Natural killer T (NKT) cells are known to play a role against certain microbial infections, including malaria and HIV, two major global infectious diseases. Strategies that can harness and amplify the immunotherapeutic potential of NKT cells can serve as powerful tools in the fight against such diseases. 7DW8-5, a novel glycolipid, may be one such tool. The interaction of 7DW8-5 with CD1d molecules induces activation of NKT cells, thereby activating various immune-competent cells including dendritic cells (DCs) to provide a significant adjuvant effect for several vaccines. This review discusses the discovery and characterization of 7DW8-5 and the practical considerations of its preclinical and clinical development as a potential glycolipid adjuvant for candidate malaria and HIV vaccines. Copyright © 2010. Published by Elsevier Inc.

Immunologic analyses of mouse cystathionase in normal and leukemic cells

International Nuclear Information System (INIS)

Bikel, I.; Faibes, D.; Uren, J.R.; Livingston, D.M.

1978-01-01

Rabbit antisera have been raised against mouse liver cystathionase and shown to possess enzyme neutralizing activity. Agar gel double immunodiffusion analyses demonstrated that both mouse liver cystathionase and rat liver cystathionase react with the antisera, the latter enzyme being completely cross-reactive with the former. Following radioiodination of the purified rat liver enzyme, a double antibody radioimmunoassay was developed in which greater than 90% of the labeled protein could be specifically precipitated with the anti-mouse cystathionase antibodies. In this test the purified rat liver and mouse liver enzymes were virtually indistinguishable, generating superimposable competition displacement curves on a protein mass basis. These results indicate that both enzymes are immunologically identical, thus validating the use of the rat in lieu of the murine liver enzyme as radiolabeled tracer in an assay for mouse cystathionase. In addition, competition radioimmunoassays demonstrated that the immunological reactivities of both the purified rat liver and mouse liver enzymes were equally heat sensitive. The sensitivity of the assay was determined to be 1 ng of enzyme protein/0.22 mL of assay mixture, and the assay could be used to detect the presence of enzyme protein in tissue homogenates of single mouse organs. Mouse or rat cross-reactivity with human liver cystathionase was incomplete; but, with the exception of heart and spleen, parallel radioimmunoassay competition displacement curves were obtained for cystathionase from different mouse organs including thymus. Extracts of 7-, 9-, and 10-month-old spontaneous AKR mouse thymomas were tested in the radioimmunoassay along with extracts of age-matched thymuses which were grossly tumor free. A reaction of nonidentity was observed for all of the tumor extracts while a reaction identical with that of the pure liver enzyme was found with all of the normal thymus extracts

Ectopic expression of the calcium-binding protein parvalbumin in mouse liver endothelial cells

DEFF Research Database (Denmark)

Castillo, M B; Berchtold, M W; Rülicke, T

1997-01-01

To elucidate the physiological role of the Ca2+ binding protein parvalbumin, we have generated transgenic mice carrying the full-length complementary DNA (cDNA) of rat parvalbumin under the control of the heavy-metal inducible metallothionein IIA promoter. Immunohistochemical and biochemical...... methods have been used to detect the presence of ectopic parvalbumin expression in different tissues. Here we show the expression of parvalbumin in endothelial cells lining the liver sinusoids in situ and after isolation in vitro. The hemodynamic effects of endothelin 1, a peptide hormone mediating potent...... vasoconstriction via calcium signalling, were investigated in the mouse liver perfused in situ. Vasoconstriction, thought to be mediated by the Ito cell, was not affected in the transgenic animals, whereas microvascular exchange, probed with the multiple indicator dilution technique, was markedly decreased...

Increased Numbers of NK Cells, NKT-Like Cells, and NK Inhibitory Receptors in Peripheral Blood of Patients with Chronic Obstructive Pulmonary Disease

Directory of Open Access Journals (Sweden)

Ying Tang

2013-01-01

Full Text Available T cells and B cells participate in the pathogenesis of COPD. Currently, NK cells and NKT cells have gained increasing attention. In the present study, 19 COPD patients and 12 healthy nonsmokers (HNS were recruited, and their pulmonary function was assessed. The frequencies of CD3+ T, CD4+ T, CD8+ T, B, NK, and NKT-like cells were determined using flow cytometry. The frequencies of spontaneous and inducible IFN-γ+ or CD107a+ NK and NKT-like cells as well as activating or inhibitory receptors were also detected. The potential association of lymphocyte subsets with disease severity was further analyzed. Significantly decreased numbers of CD3+ and CD4+ T cells, and the CD4+/CD8+ ratio, but increased numbers of CD3−CD56+ NK and CD3+CD56+ NKT-like cells were observed in COPD patients compared to HNS. The frequencies of inducible IFN-γ-secreting NK and NKT-like cells were less in COPD patients. The frequencies of CD158a and CD158b on NK cells and CD158b on NKT-like cells were greater. The frequency of CD158b+ NK cells was negatively correlated with FEV1% prediction and FEV1/FVC. Our data indicate that COPD patients have immune dysfunction, and higher frequencies of inhibitory NK cells and NKT-like cells may participate in the pathogenesis of COPD.

Cutting edge: Rapid recovery of NKT cells upon institution of highly active antiretroviral therapy for HIV-1 infection

NARCIS (Netherlands)

van der Vliet, Hans J. J.; van Vonderen, Marit G. A.; Molling, Johan W.; Bontkes, Hetty J.; Reijm, Martine; Reiss, Peter; van Agtmael, Michiel A.; Danner, Sven A.; van den Eertwegh, Alfons J. M.; von Blomberg, B. Mary E.; Scheper, Rik J.

2006-01-01

CD1d-restricted NKT cells play important regulatory roles in various immune responses and are rapidly and selectively depleted upon infection with HIV-1. The cause of this selective depletion is incompletely understood, although it is in part due to the high susceptibility of CD4+ NKT cells to

Cholesterol esterification by mouse liver homogenate. Contribution to the study of ACYL-CoA: Cholesterol ACYL transferase in mammalian liver

International Nuclear Information System (INIS)

Soares, M.G.C.B.

1976-01-01

A cholesterol- esterifying enzyme from mouse liver has been partially characterized. The enzyme which showed optimum activity at pH 7,1 and required ATP and CoA, was identified as an acyl CoA: cholesterol acyl transferase (E.C.2.3.1.26). As a fuction of time the percentage of esterified cholesterol increased linearly during the first hour of incubation and continued to increase but not linearly with 4 hours, after which time no further net esterefication was observed. The relative concentration of esterified cholesterol remained constant between the fourth and twelveth hours of incubation but afterwards decreased when the incubation continued until 24 hours. The cholesterol- esterifying activity was 24,0+- 2,9 nmoles cholesterol esterified per gram tissue wet weight per minute. The mean percentages of free cholesterol esterified in and 24 hours respectively were 14,8+- 1,6 e 21,9+- 4,5. The subfractionation of labelled cholesteryl esters after one hour incubation of liver homogenate with 4-C 14 -Cholesterol showed the order of preference for the formation of the different ester classes to be monounsatured > diunsatured ≥ saturated >> polyunsaturated. The properties of the enzyme frommouse liver do not markedly differ from those of the previously recorded ACAT activity of rat liver. (Author) [pt

Decline in peripheral blood NKG2D+CD3+CD56+ NKT cells in metastatic colorectal cancer patients.

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Gharagozloo, M; Rezaei, A; Kalantari, H; Bahador, A; Hassannejad, N; Maracy, M; Nouri, N; Sedghi, M; Ghazanfari, H; Bayat, B

2018-01-01

Colorectal cancer (CRC) is one of the main causes of cancer deaths in the world. This cancer can be divided into non-metastatic and metastatic CRC stages. CD3+CD56+ NKT cell subsets are a minor T cell subset in peripheral blood and conduct the killing of tumor cells in direct manner. Little is obvious about levels and surface markers of these cells such as NKG2D in different cancers, especially in CRC. We included 15 non-metastatic (low-grade), 11 non-metastatic (high-grade), 10 metastatic colorectal cancer patients and 18 healthy controls. The percentages of CD3+CD56+ NKT cells and NKG2D+CD56+ NKT cells from samples were analyzed by flow cytometry in peripheral blood mononuclear cells (PBMCs) of samples. We found that there was a significantly lower number of NKG2D+CD3+CD56+ cells in peripheral blood of patients with metastatic colorectal cancer compared with normal controls (77.53 ± 5.79 % vs 90.74 ± 9.84 %; pNKT cells was significantly lower in patients with metastatic colorectal cancer compared to healthy controls strengthens the hypothesis that NKT cells can play a substantial role in the protection against human colorectal cancer, and this opens up avenues for novel studies about elucidating the other aspects of tumor surveillance in CRC progression and immunotherapy (Tab. 2, Fig. 2, Ref. 46).

Papel de las células nkt invariantes en la respuesta inmune anti-viral

OpenAIRE

Román, Alejandro; Rugeles, María Teresa; Montoya, Carlos Julio

2006-01-01

Las células T asesinas naturales con receptor de células T invariante y restringidas por la molécula CD1d (iNKT) son un subgrupo de linfocitos con potente actividad inmunorreguladora; su respuesta casi inmediata y la capacidad de producir citoquinas tanto Th1 como Th2 son factores determinantes en el desarrollo de la respuesta inmune innata y adaptativa. El papel fisiológico de las células iNKT se ha documentado ampliamente en la respuesta anti-tumoral, el desarrollo de la tolerancia en los ó...

NKG2D performs two functions in invariant NKT cells: direct TCR-independent activation of NK-like cytolysis and co-stimulation of activation by CD1d.

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Kuylenstierna, Carlotta; Björkström, Niklas K; Andersson, Sofia K; Sahlström, Peter; Bosnjak, Lidija; Paquin-Proulx, Dominic; Malmberg, Karl-Johan; Ljunggren, Hans-Gustaf; Moll, Markus; Sandberg, Johan K

2011-07-01

Invariant NKT cells are important in the activation and regulation of immune responses. They can also function as CD1d-restricted killer cells. However, the role of activating innate NK-cell receptors expressed on NKT cells in triggering cytolytic function is poorly characterized. Here, we initially confirmed that the cellular stress-ligand receptor NKG2D is expressed on CD4- NKT cells, whereas most CD4+ NKT cells lack this receptor. Interestingly, NKG2D+ NKT cells frequently expressed perforin, and both NKG2D and perforin localized at the site of contact with NKG2D ligand-expressing target cells. CD4- NKT cells degranulated in response to NKG2D engagement in a redirected activation assay independent of stimulation via their invariant TCR. NKT cells killed P815 cells coated with anti-NKG2D mAb and CD1d-negative K562 tumor target cells in an NKG2D-dependent manner. Furthermore, NKG2D engagement co-stimulated TCR-mediated NKT-cell activation in response to endogenous CD1d-presented ligands or suboptimal levels of anti-CD3 triggering. These data indicate that the CD4- subset of human NKT cells can mediate direct lysis of target cells via NKG2D engagement independent of CD1d, and that NKG2D also functions as a co-stimulatory receptor in these cells. NKG2D thus plays both a direct and a co-stimulatory role in the activation of NKT cells. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Immature murine NKT cells pass through a stage of developmentally programmed innate IL-4 secretion

Science.gov (United States)

Dickgreber, Nina; Farrand, Kathryn J.; van Panhuys, Nicholas; Knight, Deborah A.; McKee, Sara J.; Chong, Mei L.; Miranda-Hernandez, Socorro; Baxter, Alan G.; Locksley, Richard M.; Le Gros, Graham; Hermans, Ian F.

2012-01-01

We assessed the production of the canonical Th2 cytokine IL-4 by NKT cells directly in vivo using IL-4-substituting strains of reporter mice that provide faithful and sensitive readouts of cytokine production without the confounding effects of in vitro stimulation. Analysis in naïve animals revealed an “innate” phase of IL-4 secretion that did not need to be triggered by administration of a known NKT cell ligand. This secretion was by immature NKT cells spanning Stage 1 of the maturation process in the thymus (CD4+ CD44lo NK1.1− cells) and Stage 2 (CD4+ CD44hi NK1.1− cells) in the spleen. Like ligand-induced IL-4 production by mature cells, this innate activity was independent of an initial source of IL-4 protein and did not require STAT6 signaling. A more sustained level of innate IL-4 production was observed in animals on a BALB/c background compared with a C57BL/6 background, suggesting a level of genetic regulation that may contribute to the “Th2-prone” phenotype in BALB/c animals. These observations indicate a regulated pattern of IL-4 expression by maturing NKT cells, which may endow these cells with a capacity to influence the development of surrounding cells in the thymus. PMID:22941735

Metabolism of ginger component [6]-shogaol in liver microsomes from mouse, rat, dog, monkey, and human.

Science.gov (United States)

Chen, Huadong; Soroka, Dominique; Zhu, Yingdong; Sang, Shengmin

2013-05-01

There are limited data on the metabolism of [6]-shogaol (6S), a major bioactive component of ginger. This study demonstrates metabolism of 6S in liver microsomes from mouse, rat, dog, monkey, and human. The in vitro metabolism of 6S was compared among five species using liver microsomes from mouse, rat, dog, monkey, and human. Following incubations with 6S, three major reductive metabolites 1-(4'-hydroxy-3'-methoxyphenyl)-4-decen-3-ol (M6), 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-ol (M9), and 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-one (M11), as well as two new oxidative metabolites (1E,4E)-1-(4'-hydroxy-3'-methoxyphenyl)-deca-1,4-dien-3-one (M14) and (E)-1-(4'-hydroxy-3'-methoxyphenyl)-dec-1-en-3-one (M15) were found in all species. The kinetic parameters of M6 in liver microsomes from each respective species were quantified using Michaelis-Menten theory. A broad CYP-450 inhibitor, 1-aminobenzotriazole, precluded the formation of oxidative metabolites, M14 and M15, and 18β-glycyrrhetinic acid, an aldo-keto reductase inhibitor, eradicated the formation of the reductive metabolites M6, M9, and M11 in all species. Metabolites M14 and M15 were tested for cancer cell growth inhibition and induction of apoptosis and both showed substantial activity, with M14 displaying greater potency than 6S. We conclude that 6S is metabolized extensively in mammalian species mouse, rat, dog, monkey, and human, and that there are significant interspecies differences to consider when planning preclinical trials toward 6S chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid and preferential distribution of blood-borne αCD3εAb to the liver is followed by local stimulation of T cells and natural killer T cells

Science.gov (United States)

Wingender, Gerhard; Schumak, Beatrix; Schurich, Anna; Gessner, J Engelbert; Endl, Elmar; Limmer, Andreas; Knolle, Percy A

2006-01-01

Dissemination of soluble molecules or antigens via the blood stream is considered to lead to a uniform distribution in the various organs of the body, but organ-specific microarchitecture and vascularization may influence this. Following intravenous injection of αCD3ε antibody (αCD3εAb) we observed clear differences in antibody binding to Fcγ receptor (FcγR)+ antigen-presenting cells (APCs) or T lymphocytes in different organs. Significant binding of blood-borne αCD3εAb was only detected in the spleen and liver and not in the thymus or lymph node. In the spleen, only 10% of dendritic cells/macrophages and 40% of T-cell receptor (TCR)-β+ cells were positive for αCD3εAb, and, dependent on FcγR-mediated cross-linking of αCD3εAb, a similar percentage of splenic TCR-β+ cells were stimulated and became CD69+. Stimulation of TCR-β+ cells in the liver was at least as efficient as in the spleen, but almost all T cells and all scavenger liver sinusoidal endothelial cells bound αCD3εAb. In contrast to CD69 up-regulation, only CD4+ natural killer T (NKT) cells and CD11ahigh CD8+ T cells were activated by αCD3εAb and expressed interferon (IFN)-γ. Again, IFN-γ release from NKT/T cells was at least as efficient in the liver as in the spleen. Taken together, our results support the notion that the combination of extensive hepatic vascularization and very high scavenger activity allows the liver to fulfill its metabolic tasks and to promote stimulation of the large but widely distributed hepatic population of NKT/T cells. PMID:16423047

Uptake and disposition of mirex in hepatocytes and subcellular fractions in CD1 mouse liver

International Nuclear Information System (INIS)

Charles, A.K.; Rosenbaum, D.P.; Ashok, L.; Abraham, R.

1985-01-01

In vivo uptake and disposition of [ 14 C]mirex by CD1 mouse liver subcellular fractions and cells of different nuclear ploidy were examined following single or multiple doses of mirex injected intraperitoneally. Significant amounts of mirex were rapidly taken up by liver (21-29%), suggesting that liver is one of the primary sites of accumulation of the chemical. Among subcellular fractions, mirex was predominantly distributed in mitochondria and microsomes in the irreversibly bound form (about 20%), although its levels fluctuated considerably with time. Mirex was completely dissociated with trichloroacetic acid treatment from both nuclear and plasma membrane fractions, although the total uptake by these fractions was markedly high. The time course of uptake and concentration-dependent disposition of mirex revealed that polyploid hepatocytes selectively accumulated higher amounts of the chemical (two to three times) compared to diploid hepatocytes. The increased affinity of polyploid cells to mirex may indicate a greater susceptibility of this cell type to the chemical insult and also may suggest a possible early involvement of polyploids in the tumorigenic process in rodent livers

Raising the Roof: The Preferential Pharmacological Stimulation of Th1 and Th2 Responses Mediated by NKT Cells

Science.gov (United States)

East, James E.; Kennedy, Andrew J.; Webb, Tonya J.

2014-01-01

Natural killer T (NKT) cells serve as a bridge between the innate and adaptive immune systems, and manipulating their effector functions can have therapeutic significances in the treatment of autoimmunity, transplant biology, infectious disease, and cancer. NKT cells are a subset of T cells that express cell-surface markers characteristic of both natural killer cells and T cells. These unique immunologic cells have been demonstrated to serve as a link between the innate and adaptive immune systems through their potent cytokine production following the recognition of a range of lipid antigens, mediated through presentation of the major histocompatibility complex (MHC) class I like CD1d molecule, in addition to the NKT cell′s cytotoxic capabilities upon activation. Although a number of glycolipid antigens have been shown to complex with CD1d molecules, most notably the marine sponge derived glycolipid alpha-galactosylceramide (α-GalCer), there has been debate as to the identity of the endogenous activating lipid presented to the T-cell receptor (TCR) via the CD1d molecule on antigen-presenting cells (APCs). This review aims to survey the use of pharmacological agents and subsequent structure–activity relationships (SAR) that have given insight into the binding interaction of glycolipids with both the CD1d molecules as well as the TCR and the subsequent immunologic response of NKT cells. These studies not only elucidate basic binding interactions but also pave the way for future pharmacological modulation of NKT cell responses. PMID:23239102

Improving Mycobacterium bovis bacillus Calmette-Guèrin as a vaccine delivery vector for viral antigens by incorporation of glycolipid activators of NKT cells.

Science.gov (United States)

Venkataswamy, Manjunatha M; Ng, Tony W; Kharkwal, Shalu S; Carreño, Leandro J; Johnson, Alison J; Kunnath-Velayudhan, Shajo; Liu, Zheng; Bittman, Robert; Jervis, Peter J; Cox, Liam R; Besra, Gurdyal S; Wen, Xiangshu; Yuan, Weiming; Tsuji, Moriya; Li, Xiangming; Ho, David D; Chan, John; Lee, Sunhee; Frothingham, Richard; Haynes, Barton F; Panas, Michael W; Gillard, Geoffrey O; Sixsmith, Jaimie D; Korioth-Schmitz, Birgit; Schmitz, Joern E; Larsen, Michelle H; Jacobs, William R; Porcelli, Steven A

2014-01-01

Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG) has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approach of incorporating glycolipids that activate CD1d-restricted natural killer T (NKT) cells to enhance priming of CD8+ T cells by rBCG strains expressing an SIV Gag antigen (rBCG-SIV gag). We found that the incorporation of the synthetic NKT activating glycolipid α-galactosylceramide (α-GC) into rBCG-SIV gag significantly enhanced CD8+ T cell responses against an immunodominant Gag epitope, compared to responses primed by unmodified rBCG-SIV gag. The abilities of structural analogues of α-GC to enhance CD8+ T cell responses to rBCG were compared in both wild type and partially humanized mice that express human CD1d molecules in place of mouse CD1d. These studies identified an α-GC analogue known as 7DW8-5, which has previously been used successfully as an adjuvant in non-human primates, as a promising compound for enhancing immunogenicity of antigens delivered by rBCG.vectors. Our findings support the incorporation of synthetic glycolipid activators of NKT cells as a novel approach to enhance the immunogenicity of rBCG-vectored antigens for induction of CD8+ T cell responses. The glycolipid adjuvant 7DW8-5 may be a promising candidate for advancing to non-human primate and human clinical studies for the development of HIV vaccines based on rBCG vectors.

Improving Mycobacterium bovis bacillus Calmette-Guèrin as a vaccine delivery vector for viral antigens by incorporation of glycolipid activators of NKT cells.

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Manjunatha M Venkataswamy

Full Text Available Recombinant Mycobacterium bovis bacillus Calmette-Guèrin (rBCG has been explored as a vector for vaccines against HIV because of its ability to induce long lasting humoral and cell mediated immune responses. To maximize the potential for rBCG vaccines to induce effective immunity against HIV, various strategies are being employed to improve its ability to prime CD8+ T cells, which play an important role in the control of HIV infections. In this study we adopted a previously described approach of incorporating glycolipids that activate CD1d-restricted natural killer T (NKT cells to enhance priming of CD8+ T cells by rBCG strains expressing an SIV Gag antigen (rBCG-SIV gag. We found that the incorporation of the synthetic NKT activating glycolipid α-galactosylceramide (α-GC into rBCG-SIV gag significantly enhanced CD8+ T cell responses against an immunodominant Gag epitope, compared to responses primed by unmodified rBCG-SIV gag. The abilities of structural analogues of α-GC to enhance CD8+ T cell responses to rBCG were compared in both wild type and partially humanized mice that express human CD1d molecules in place of mouse CD1d. These studies identified an α-GC analogue known as 7DW8-5, which has previously been used successfully as an adjuvant in non-human primates, as a promising compound for enhancing immunogenicity of antigens delivered by rBCG.vectors. Our findings support the incorporation of synthetic glycolipid activators of NKT cells as a novel approach to enhance the immunogenicity of rBCG-vectored antigens for induction of CD8+ T cell responses. The glycolipid adjuvant 7DW8-5 may be a promising candidate for advancing to non-human primate and human clinical studies for the development of HIV vaccines based on rBCG vectors.

Time-course comparison of xenobiotic activators of CAR and PPARα in mouse liver

International Nuclear Information System (INIS)

Ross, Pamela K.; Woods, Courtney G.; Bradford, Blair U.; Kosyk, Oksana; Gatti, Daniel M.; Cunningham, Michael L.; Rusyn, Ivan

2009-01-01

Constitutive androstane receptor (CAR) and peroxisome proliferator activated receptor (PPAR)α are transcription factors known to be primary mediators of liver effects, including carcinogenesis, by phenobarbital-like compounds and peroxisome proliferators, respectively, in rodents. Many similarities exist in the phenotypes elicited by these two classes of agents in rodent liver, and we hypothesized that the initial transcriptional responses to the xenobiotic activators of CAR and PPARα will exhibit distinct patterns, but at later time-points these biological pathways will converge. In order to capture the global transcriptional changes that result from activation of these nuclear receptors over a time-course in the mouse liver, microarray technology was used. First, differences in basal expression of liver genes between C57Bl/6J wild-type and Car-null mice were examined and 14 significantly differentially expressed genes were identified. Next, mice were treated with phenobarbital (100 mg/kg by gavage for 24 h, or 0.085% w/w diet for 7 or 28 days), and liver gene expression changes with regards to both time and treatment were identified. While several pathways related to cellular proliferation and metabolism were affected by phenobarbital in wild-type mice, no significant changes in gene expression were found over time in the Car-nulls. Next, we determined commonalities and differences in the temporal response to phenobarbital and WY-14,643, a prototypical activator of PPAR α. Gene expression signatures from livers of wild-type mice C57Bl6/J mice treated with PB or WY-14,643 were compared. Similar pathways were affected by both compounds; however, considerable time-related differences were present. This study establishes common gene expression fingerprints of exposure to activators of CAR and PPARα in rodent liver and demonstrates that despite similar phenotypic changes, molecular pathways differ between classes of chemical carcinogens

Activation of iNKT Cells Prevents Salmonella-Enterocolitis and Salmonella-Induced Reactive Arthritis by Downregulating IL-17-Producing γδT Cells

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Mariángeles Noto Llana

2017-09-01

Full Text Available Reactive arthritis (ReA is an inflammatory condition of the joints that arises following an infection. Salmonella enterocolitis is one of the most common infections leading to ReA. Although the pathogenesis remains unclear, it is known that IL-17 plays a pivotal role in the development of ReA. IL-17-producers cells are mainly Th17, iNKT, and γδT lymphocytes. It is known that iNKT cells regulate the development of Th17 lineage. Whether iNKT cells also regulate γδT lymphocytes differentiation is unknown. We found that iNKT cells play a protective role in ReA. BALB/c Jα18−/− mice suffered a severe Salmonella enterocolitis, a 3.5-fold increase in IL-17 expression and aggravated inflammation of the synovial membrane. On the other hand, activation of iNKT cells with α-GalCer abrogated IL-17 response to Salmonella enterocolitis and prevented intestinal and joint tissue damage. Moreover, the anti-inflammatory effect of α-GalCer was related to a drop in the proportion of IL-17-producing γδT lymphocytes (IL17-γδTcells rather than to a decrease in Th17 cells. In summary, we here show that iNKT cells play a protective role against Salmonella-enterocolitis and Salmonella-induced ReA by downregulating IL17-γδTcells.

Metabolomics (liver and blood profiling) in a mouse model in response to fasting: A study of hepatic steatosis

NARCIS (Netherlands)

Ginneken, V. van; Verhey, E.; Poelmann, R.; Ramakers, R.; Dijk, K.W. van; Ham, L.; Voshol, P.; Havekes, L.; Eck, M. van; Greef, J. van der

2007-01-01

A metabolomic approach was applied to a mouse model of starvation-induced hepatic steatosis. After 24 h of fasting it appears that starvation reduced the phospholipids (PL), free cholesterol (FC), and cholesterol esters (CE) content of low-density lipoproteins (LDL). In liver lipid profiles major

Immunology in the liver--from homeostasis to disease.

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Heymann, Felix; Tacke, Frank

2016-02-01

The liver is a central immunological organ with a high exposure to circulating antigens and endotoxins from the gut microbiota, particularly enriched for innate immune cells (macrophages, innate lymphoid cells, mucosal-associated invariant T (MAIT) cells). In homeostasis, many mechanisms ensure suppression of immune responses, resulting in tolerance. Tolerance is also relevant for chronic persistence of hepatotropic viruses or allograft acceptance after liver transplantation. The liver can rapidly activate immunity in response to infections or tissue damage. Depending on the underlying liver disease, such as viral hepatitis, cholestasis or NASH, different triggers mediate immune-cell activation. Conserved mechanisms such as molecular danger patterns (alarmins), Toll-like receptor signalling or inflammasome activation initiate inflammatory responses in the liver. The inflammatory activation of hepatic stellate and Kupffer cells results in the chemokine-mediated infiltration of neutrophils, monocytes, natural killer (NK) and natural killer T (NKT) cells. The ultimate outcome of the intrahepatic immune response (for example, fibrosis or resolution) depends on the functional diversity of macrophages and dendritic cells, but also on the balance between pro-inflammatory and anti-inflammatory T-cell populations. As reviewed here, tremendous progress has helped to understand the fine-tuning of immune responses in the liver from homeostasis to disease, indicating promising targets for future therapies in acute and chronic liver diseases.

The role of CD1d-restricted NKT cells in the clearance of Pseudomonas aeruginosa from the lung is dependent on the host genetic background.

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Benoit, Patrick; Sigounas, Vaia Yioula; Thompson, Jenna L; van Rooijen, Nico; Poynter, Matthew E; Wargo, Matthew J; Boyson, Jonathan E

2015-06-01

Pseudomonas aeruginosa is an important human opportunistic pathogen, accounting for a significant fraction of hospital-acquired lung infections. CD1d-restricted NKT cells comprise an unusual innate-like T cell subset that plays important roles in both bacterial and viral infections. Previous reports have differed in their conclusions regarding the role of NKT cells in clearance of P. aeruginosa from the lung. Since there is significant strain-dependent variation in NKT cell number and function among different inbred strains of mice, we investigated whether the role of NKT cells was dependent on the host genetic background. We found that NKT cells did indeed play a critical role in the clearance of P. aeruginosa from the lungs of BALB/c mice but that they played no discernible role in clearance from the lungs of C57BL/6 mice. We found that the strain-dependent role of NKT cells was associated with significant strain-dependent differences in cytokine production by lung NKT cells and that impaired clearance of P. aeruginosa in BALB/c CD1d(-/-) mice was associated with an increase in neutrophil influx to the lung and increased levels of proinflammatory cytokines and chemokines after infection. Finally, we found that the role of alveolar macrophages was also dependent on the genetic background. These data provide further support for a model in which the unusually high level of variability in NKT cell number and function among different genetic backgrounds may be an important contributor to infectious-disease susceptibility and pathology. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Abnormalities in iNKT cells are associated with impaired ability of monocytes to produce IL-10 and suppress T-cell proliferation in sarcoidosis.

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Crawshaw, Anjali; Kendrick, Yvonne R; McMichael, Andrew J; Ho, Ling-Pei

2014-07-01

Sarcoidosis is a multisystem granulomatous disorder characterized by marked T-cell expansion of T helper 1 (Th1) cells. The cause of T-cell overactivity is unknown. We hypothesized that interleukin-10 (IL-10) production by a yet undefined cell type might be defective, resulting in loss of regulation of T-cell activity. Focusing on IL-10-producing monocytes, we first showed that monocytes isolated from the peripheral blood of corticosteroid-naïve sarcoidosis patients (n = 51) produced less IL-10 compared to controls, and were less able to suppress T-cell proliferation. In addition, monocytic IL-10 production correlated negatively with disease activity score. As invariant natural killer T (iNKT) cells are known to both interact with monocytes and be reduced in sarcoidosis patients, we then asked whether iNKT-specific defects might be responsible for this reduced IL-10 production. We found that greater numbers of circulating iNKT cells was associated with higher IL-10 production. Moreover, iNKT cells enhanced monocytic IL-10 production in vitro. Defective IL-10 production and T-cell suppression by sarcoidosis monocytes could be restored following their coculture with iNKT cells, in a CD1d- and cell contact-dependent process. We suggest that reduced iNKT-cell numbers in sarcoidosis may lead to impaired monocytic IL-10 production and unchecked T-cell expansion in sarcoidosis. These findings provide fresh insight into the mechanism of sarcoidosis disease, and interaction between iNKT cells and monocytes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The percentage of iNKT cells among other immune cells at various clinical stages of laryngeal cancer

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Janusz Klatka

2016-04-01

Full Text Available Introduction: Invariant natural killer T (iNKT cells constitute a small population of immune cells that share functional and phenotypic characteristics of T lymphocytes and NK cells. Due to their involvement in specific and non-specific immune responses, iNKT cells may represent an important component of antitumor and anti-infectious immunity. Material and methods: Using flow cytometry, we analyzed the percentages of iNKT cells as well as T and B lymphocytes in peripheral blood of 50 laryngeal cancer patients at various clinical stages in comparison to healthy controls (n=15. Moreover, we determined the expression of CD25, CD69 and CD95 antigens on T lymphocytes.Results: The percentage of CD4+/CD3+ T lymphocytes in the controls was higher than in laryngeal cancer patients, both with early and late stages of the disease. The percentage of CD8+/CD3+ T lymphocytes in healthy controls was lower than in patients with early and late clinical stages of laryngeal cancer. Patients with advanced laryngeal cancer showed a lower percentage of iNKT cells and higher frequencies of T regulatory cells (Tregs than the controls. Advanced clinical stages of laryngeal cancer are associated with impaired activation of lymphocytes.Conclusions: Our study confirmed that laryngeal cancer cells exert a strong suppressor effect on the immune system of the host. This is reflected by a decrease in the percentage of iNKT cells that are capable of cancer cell elimination, and a concomitant increase in the percentage of Tregs. However, further studies are needed in order to explain the underlying mechanisms of immunosuppression and understand interactions between immune and cancer cells.

Proteomic and transcriptomic studies of HBV-associated liver fibrosis of an AAV-HBV-infected mouse model.

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Kan, Fangming; Ye, Lei; Yan, Tao; Cao, Jiaqi; Zheng, Jianhua; Li, Wuping

2017-08-22

Human hepatitis B virus (HBV) infection is an important public health issue in the Asia-Pacific region and is associated with chronic hepatitis, liver fibrosis, cirrhosis and even liver cancer. However, the underlying mechanisms of HBV-associated liver fibrosis remain incompletely understood. In the present study, proteomic and transcriptomic approaches as well as biological network analyses were performed to investigate the differentially expressed molecular signature and key regulatory networks that were associated with HBV-mediated liver fibrosis. RNA sequencing and 2DE-MALDI-TOF/TOF were performed on liver tissue samples obtained from HBV-infected C57BL/6 mouse generated via AAV8-HBV virus. The results showed that 322 genes and 173 proteins were differentially expressed, and 28 HBV-specific proteins were identified by comprehensive proteomic and transcriptomic analysis. GO analysis indicated that the differentially expressed proteins were predominantly involved in oxidative stress, which plays a key role in HBV-related liver fibrosis. Importantly, CAT, PRDX1, GSTP1, NXN and BLVRB were shown to be associated with oxidative stress among the differentially expressed proteins. The most striking results were validated by Western blot and RT-qPCR. The RIG-I like receptor signaling pathway was found to be the major signal pathway that changed during HBV-related fibrosis. This study provides novel insights into HBV-associated liver fibrosis and reveals the significant role of oxidative stress in liver fibrosis. Furthermore, CAT, BLVRB, NXN, PRDX1, and IDH1 may be candidates for detection of liver fibrosis or therapeutic targets for the treatment of liver fibrosis.

Raising the roof: the preferential pharmacological stimulation of Th1 and th2 responses mediated by NKT cells.

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East, James E; Kennedy, Andrew J; Webb, Tonya J

2014-01-01

Natural killer T (NKT) cells serve as a bridge between the innate and adaptive immune systems, and manipulating their effector functions can have therapeutic significances in the treatment of autoimmunity, transplant biology, infectious disease, and cancer. NKT cells are a subset of T cells that express cell-surface markers characteristic of both natural killer cells and T cells. These unique immunologic cells have been demonstrated to serve as a link between the innate and adaptive immune systems through their potent cytokine production following the recognition of a range of lipid antigens, mediated through presentation of the major histocompatibility complex (MHC) class I like CD1d molecule, in addition to the NKT cell's cytotoxic capabilities upon activation. Although a number of glycolipid antigens have been shown to complex with CD1d molecules, most notably the marine sponge derived glycolipid alpha-galactosylceramide (α-GalCer), there has been debate as to the identity of the endogenous activating lipid presented to the T-cell receptor (TCR) via the CD1d molecule on antigen-presenting cells (APCs). This review aims to survey the use of pharmacological agents and subsequent structure-activity relationships (SAR) that have given insight into the binding interaction of glycolipids with both the CD1d molecules as well as the TCR and the subsequent immunologic response of NKT cells. These studies not only elucidate basic binding interactions but also pave the way for future pharmacological modulation of NKT cell responses. © 2012 Wiley Periodicals, Inc.

PEPCK-M expression in mouse liver potentiates, not replaces, PEPCK-C mediated gluconeogenesis

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Méndez-Lucas, Andrés; Duarte, João; Sunny, Nishanth E.; Satapati, Santhosh; He, TianTeng; Fu, Xiaorong; Bermúdez, Jordi; Burgess, Shawn C.; Perales, Jose C.

2013-01-01

Background & Aims Hepatic gluconeogenesis helps maintain systemic energy homeostasis by compensating for discontinuities in nutrient supply. Liver specific deletion of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) abolishes gluconeogenesis from mitochondrial substrates, deregulates lipid metabolism and affects TCA cycle. While, mouse liver almost exclusively expresses PEPCK-C, humans equally present a mitochondrial isozyme (PEPCK-M). Despite clear relevance to human physiology, the role of PEPCK-M and its gluconeogenic potential remain unknown. Here, we test the significance of PEPCK-M in gluconeogenesis and TCA cycle function in liver-specific PEPCK-C knockout and WT mice. Methods The effects of the overexpression of PEPCK-M were examined by a combination of tracer studies and molecular biology techniques. Partial PEPCK-C re-expression was used as a positive control. Metabolic fluxes were evaluated in isolated livers by NMR using 2H and 13C tracers. Gluconeogenic potential, together with metabolic profiling, were investigated in vivo and in primary hepatocytes. Results PEPCK-M expression partially rescued defects in lipid metabolism, gluconeogenesis and TCA cycle function impaired by PEPCK-C deletion, while ~10% re-expression of PEPCK-C normalized most parameters. When PEPCK-M was expressed in the presence of PEPCK-C, the mitochondrial isozyme amplified total gluconeogenic capacity, suggesting autonomous regulation of oxaloacetate to phosphoenolpyruvate fluxes by the individual isoforms. Conclusions We conclude that PEPCK-M has gluconeogenic potential per se, and cooperates with PEPCK-C to adjust gluconeogenic/TCA flux to changes in substrate or energy availability, hinting at a role in the regulation of glucose and lipid metabolism in human liver. PMID:23466304

CD4⁺ type II NKT cells mediate ICOS and programmed death-1-dependent regulation of type 1 diabetes

DEFF Research Database (Denmark)

Kadri, Nadir; Korpos, Eva; Gupta, Shashank

2012-01-01

Type 1 diabetes (T1D) is a chronic autoimmune disease that results from T cell-mediated destruction of pancreatic ß cells. CD1d-restricted NKT lymphocytes have the ability to regulate immunity, including autoimmunity. We previously demonstrated that CD1d-restricted type II NKT cells, which carry ...

Zonation of heme synthesis enzymes in mouse liver and their regulation by β-catenin and Ha-ras.

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Braeuning, Albert; Schwarz, Michael

2010-11-01

Cytochrome P450 (CYP) hemoproteins play an important role in hepatic biotransformation. Recently, β-catenin and Ha-ras signaling have been identified as players controlling transcription of various CYP genes in mouse liver. The aim of the present study was to analyze the role of β-catenin and Ha-ras in the regulation of heme synthesis. Heme synthesis-related gene expression was analyzed in normal liver, in transgenic mice expressing activated β-catenin or Ha-ras, and in hepatomas. Regulation of the aminolevulinate dehydratase promoter was studied in vitro. Elevated expression of mRNAs and proteins involved in heme biosynthesis was linked to β-catenin activation in perivenous hepatocytes, in transgenic hepatocytes, and in hepatocellular tumors. Stimulation of the aminolevulinate dehydratase promoter by β-catenin was independent of the β-catenin/T-cell-specific transcription factor dimer. By contrast, activation of Ha-ras repressed heme synthesis-related gene expression. The present data suggest that β-catenin enhances the expression of both CYPs and heme synthesis-related genes, thus coordinating the availability of CYP apoprotein and its prosthetic group heme. The reciprocal regulation of heme synthesis by β-catenin and Ha-ras-dependent signaling supports our previous hypothesis that antagonistic action of these pathways plays a major role in the control of zonal gene expression in healthy mouse liver and aberrant expression patterns in hepatocellular tumors.

Diminished Frequency of Menstrual and Peripheral Blood NKT-Like Cells in Patients With Unexplained Recurrent Spontaneous Abortion and Infertile Women.

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Hosseini, Samira; Shokri, Fazel; Pour, Soheila Ansari; Khoshnoodi, Jalal; Jeddi-Tehrani, Mahmood; Zarnani, Amir-Hassan

2018-01-01

Systemic monitoring of immune system may not precisely outline the local immune status in the uterus. This survey is a continuation of our previous studies on potential usefulness of menstrual blood (MB) immunophenotyping as a tool for investigation of immunological disturbances in pregnancy-related disorders. Peripheral blood (PB) and MB from healthy fertile (n = 15), unexplained recurrent spontaneous abortion (URSA; n = 15), and unexplained infertile women (n = 8) were collected simultaneously in the second day of their menstrual cycle and frequency of natural killer T (NKT)-like cell subpopulations were assessed by flow cytometry. Menstrual blood of all experimental groups contained higher percentage of TCRαβ + , CD45RO + , and CD16 - NKT-like cells compared to corresponding PB. Frequency of MB NKT-like cells in unexplained infertile participants was lower than fertile and URSA groups. Compared to normal participants, patients with URSA had lower frequency of PB TCRαβ + and higher CD16 + , while in infertile woman frequencies of PB CD45RO + , CD45RO - , CD16 - , IL17 + , and MB CD45RO + NKT-like cells were lower. Although, PB and MB seemingly have the same histological nature, our results showed that MB contained different composition of NKT-like subsets with different cytokine profiles and could be viewed as one potential biological sample for evaluation of patients with infertility and URSA.

Interferon alpha treatment stimulates interferon gamma expression in type I NKT cells and enhances their antiviral effect against hepatitis C virus.

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Miyaki, Eisuke; Hiraga, Nobuhiko; Imamura, Michio; Uchida, Takuro; Kan, Hiromi; Tsuge, Masataka; Abe-Chayama, Hiromi; Hayes, C Nelson; Makokha, Grace Naswa; Serikawa, Masahiro; Aikata, Hiroshi; Ochi, Hidenori; Ishida, Yuji; Tateno, Chise; Ohdan, Hideki; Chayama, Kazuaki

2017-01-01

Interferon (IFN) inhibits hepatitis C virus (HCV) replication through up-regulation of intrahepatic IFN-stimulated gene expression but also through activation of host immune cells. In the present study, we analyzed the immune cell-mediated antiviral effects of IFN-α using HCV-infected mice. Urokinase-type plasminogen activator (uPA)-severe combined immunodeficiency (SCID) mice with transplanted human hepatocytes were infected with genotype 1b HCV and injected with human peripheral blood mononuclear cells (PBMCs). IFN-α treatment following human PBMC transplantation resulted in a significant reduction in serum HCV RNA titers and a higher human CD45-positive mononuclear cell chimerism compared to mice without human PBMC transplantation. In mice with human PBMCs treated with IFN-α, serum concentrations of IFN-γ increased, and natural killer T (NKT) cells, especially type I NKT cells, produced IFN-γ. Mice in which IFN-γ signaling was blocked using antibody or in which transplanted PBMCs were depleted for type I NKT cells showed similar levels of anti-HCV effect compared with mice treated only with IFN-α. These results show that IFN-α stimulates IFN-γ expression in type 1 NKT cells and enhances the inhibition of HCV replication. We propose that type 1 NKT cells might represent a new therapeutic target for chronic hepatitis C patients.

Nuclear receptor CAR (NR1I3) is essential for DDC-induced liver injury and oval cell proliferation in mouse liver.

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Yamazaki, Yuichi; Moore, Rick; Negishi, Masahiko

2011-11-01

The liver is endowed with the ability to regenerate hepatocytes in response to injury. When this regeneration ability is impaired during liver injury, oval cells, which are considered to be postnatal hepatic progenitors, proliferate and differentiate into hepatocytes. Here we have demonstrated that 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) activates the nuclear receptor constitutive active/androstane receptor (CAR), resulting in proliferation of oval cells in mouse liver. Activation of CAR by DDC was shown by hepatic nuclear CAR accumulation and cytochrome P450 (CYP)2B10 mRNA induction after feeding a 0.1% DDC-containing diet to Car(+/+) mice. After being fed the DDC diet, Car(+/+), but not Car(-/-) mice, developed severe liver injury and an A6 antibody-stained ductular reaction in an area around the portal tract. Oval cell proliferation was confirmed by laser capture microdissection and real-time PCR; mRNAs for the two oval cell markers epithelial cell adhesion molecule and TROP2 were specifically induced in the periportal region of DDC diet-fed Car(+/+), but not Car(-/-) mice. Although rates of both hepatocyte growth and death were initially enhanced only in DDC diet-fed Car(+/+) mice, growth was attenuated when oval cells proliferated, whereas death continued unabated. DDC-induced liver injury, which differs from other CAR activators such as phenobarbital, occurred in the periportal region where cells developed hypertrophy, accumulated porphyrin crystals and inflammation developed, all in association with the proliferation of oval cells. Thus, CAR provides an excellent experimental model for further investigations into its roles in liver regeneration, as well as the development of diseases such as hepatocellular carcinoma.

Ursodeoxycholic Acid Suppresses Lipogenesis in Mouse Liver: Possible Role of the Decrease in β-Muricholic Acid, a Farnesoid X Receptor Antagonist.

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Fujita, Kyosuke; Iguchi, Yusuke; Une, Mizuho; Watanabe, Shiro

2017-04-01

The farnesoid X receptor (FXR) is a major nuclear receptor of bile acids; its activation suppresses sterol regulatory element-binding protein 1c (SREBP1c)-mediated lipogenesis and decreases the lipid contents in the liver. There are many reports showing that the administration of ursodeoxycholic acid (UDCA) suppresses lipogenesis and reduces the lipid contents in the liver of experimental animals. Since UDCA is not recognized as an FXR agonist, these effects of UDCA cannot be readily explained by its direct activation of FXR. We observed that the dietary administration of UDCA in mice decreased the expression levels of SREBP1c and its target lipogenic genes. Alpha- and β-muricholic acids (MCA) and cholic acid (CA) were the major bile acids in the mouse liver but their contents decreased upon UDCA administration. The hepatic contents of chenodeoxycholic acid and deoxycholic acid (DCA) were relatively low but were not changed by UDCA. UDCA did not show FXR agonistic or antagonistic potency in in vitro FXR transactivation assay. Taking these together, we deduced that the above-mentioned change in hepatic bile acid composition induced upon UDCA administration might cause the relative increase in the FXR activity in the liver, mainly by the reduction in the content of β-MCA, a farnesoid X receptor antagonist, which suggests a mechanism by which UDCA suppresses lipogenesis and decreases the lipid contents in the mouse liver.

IFN-γ-producing NKT cells exacerbate sepsis by enhancing C5a generation via IL-10-mediated inhibition of CD55 expression on neutrophils.

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Kim, Ji Hyung; Oh, Sae Jin; Ahn, Sehee; Chung, Doo Hyun

2014-07-01

A role for NKT cells has been implicated in sepsis, but the mechanism by which NKT cells contribute to sepsis remains unclear. Here, we examined WT and NKT-cell-deficient mice of C57BL/6 background during cecal ligation and puncture-induced sepsis. The levels of C5a, IFN-γ, and IL-10 were higher in the serum and peritoneal fluid of WT mice than in those of CD1d(-/-) mice, while the mortality rate was lower in CD1d(-/-) mice than in WT mice. C5a blockade decreased mortality of WT mice during sepsis, whereas it did not alter that of CD1d(-/-) mice. As assessed by intracellular staining, NKT cells expressed IFN-γ, while neutrophils expressed IL-10. Upon coculture, IL-10-deficient NKT cells enhanced IL-10 production by WT, but not IFN-γR-deficient, neutrophils. Meanwhile, CD1d(-/-) mice exhibited high CD55 expression on neutrophils during sepsis, whereas those cells from WT mice expressed minimal levels of CD55. Recombinant IL-10 administration into CD1d(-/-) mice reduced CD55 expression on neutrophils. Furthermore, adoptive transfer of sorted WT, but not IFN-γ-deficient, NKT cells into CD1d(-/-) mice suppressed CD55 expression on neutrophils, but increased IL-10 and C5a levels. Taken together, IFN-γ-producing NKT cells enhance C5a generation via IL-10-mediated inhibition of CD55 expression on neutrophils, thereby exacerbating sepsis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An optimized method for mouse liver sinusoidal endothelial cell isolation

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Meyer, Jeremy, E-mail: jeremy.meyer@hcuge.ch [Division of Digestive and Transplantation Surgery, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Genève 14 (Switzerland); Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Lacotte, Stéphanie, E-mail: stephanie.lacotte@unige.ch [Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Morel, Philippe, E-mail: philippe.morel@hcuge.ch [Division of Digestive and Transplantation Surgery, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Genève 14 (Switzerland); Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Gonelle-Gispert, Carmen, E-mail: carmen.gonelle@unige.ch [Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Bühler, Léo, E-mail: leo.buhler@hcuge.ch [Division of Digestive and Transplantation Surgery, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Genève 14 (Switzerland); Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland)

2016-12-10

The objective of the present study was to develop an accurate and reproducible method for liver sinusoidal endothelial cell (LSEC) isolation in mice. Non-parenchymal cells were isolated using a modified two-step collagenase digestion combined with Optiprep density gradient centrifugation. LSEC were further purified using two prevalent methods, short-term selective adherence and CD146+ magnetic-activated cell sorting (MACS), and compared in terms of cell yield, viability and purity to our purification technique using CD11b cell depletion combined with long-term selective adherence. LSEC purification using our technique allowed to obtain 7.07±3.80 million LSEC per liver, while CD146+ MACS and short-term selective adherence yielded 2.94±1.28 and 0.99±0.66 million LSEC, respectively. Purity of the final cell preparation reached 95.10±2.58% when using our method. In contrast, CD146+ MACS and short-term selective adherence gave purities of 86.75±3.26% and 47.95±9.82%, respectively. Similarly, contamination by non-LSEC was the lowest when purification was performed using our technique, with a proportion of contaminating macrophages of only 1.87±0.77%. Further, isolated cells analysed by scanning electron microscopy presented typical LSEC fenestrations organized in sieve plates, demonstrating that the technique allowed to isolate bona fide LSEC. In conclusion, we described a reliable and reproducible technique for the isolation of high yields of pure LSEC in mice. This protocol provides an efficient method to prepare LSEC for studying their biological functions. - Highlights: • This protocol provides an efficient method to prepare primary mouse LSEC for studying their biological functions. • The liver cell dispersion step was improved by performing a retrograde cannulation of the liver. • The cell yield and the purity obtained were higher than comparative techniques in mice. • Contaminating macrophages were removed by introducing a CD11b- magnetic �

An optimized method for mouse liver sinusoidal endothelial cell isolation

International Nuclear Information System (INIS)

Meyer, Jeremy; Lacotte, Stéphanie; Morel, Philippe; Gonelle-Gispert, Carmen; Bühler, Léo

2016-01-01

The objective of the present study was to develop an accurate and reproducible method for liver sinusoidal endothelial cell (LSEC) isolation in mice. Non-parenchymal cells were isolated using a modified two-step collagenase digestion combined with Optiprep density gradient centrifugation. LSEC were further purified using two prevalent methods, short-term selective adherence and CD146+ magnetic-activated cell sorting (MACS), and compared in terms of cell yield, viability and purity to our purification technique using CD11b cell depletion combined with long-term selective adherence. LSEC purification using our technique allowed to obtain 7.07±3.80 million LSEC per liver, while CD146+ MACS and short-term selective adherence yielded 2.94±1.28 and 0.99±0.66 million LSEC, respectively. Purity of the final cell preparation reached 95.10±2.58% when using our method. In contrast, CD146+ MACS and short-term selective adherence gave purities of 86.75±3.26% and 47.95±9.82%, respectively. Similarly, contamination by non-LSEC was the lowest when purification was performed using our technique, with a proportion of contaminating macrophages of only 1.87±0.77%. Further, isolated cells analysed by scanning electron microscopy presented typical LSEC fenestrations organized in sieve plates, demonstrating that the technique allowed to isolate bona fide LSEC. In conclusion, we described a reliable and reproducible technique for the isolation of high yields of pure LSEC in mice. This protocol provides an efficient method to prepare LSEC for studying their biological functions. - Highlights: • This protocol provides an efficient method to prepare primary mouse LSEC for studying their biological functions. • The liver cell dispersion step was improved by performing a retrograde cannulation of the liver. • The cell yield and the purity obtained were higher than comparative techniques in mice. • Contaminating macrophages were removed by introducing a CD11b- magnetic �

Histone deacetylase 2 is decreased in peripheral blood pro-inflammatory CD8+ T and NKT-like lymphocytes following lung transplant.

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Hodge, Greg; Hodge, Sandra; Holmes-Liew, Chien-Li; Reynolds, Paul N; Holmes, Mark

2017-02-01

Immunosuppression therapy following lung transplantation fails to prevent chronic rejection in many patients, which is associated with lack of suppression of cytotoxic mediators and pro-inflammatory cytokines in peripheral blood T and natural killer T (NKT)-like cells. Histone acetyltransferases (HATs) and histone deacetylases (HDACs) upregulate/downregulate pro-inflammatory gene expression, respectively; however, differences in the activity of these enzymes following lung transplant are unknown. We hypothesized decreased HDAC2 expression and increased HAT expression in pro-inflammatory lymphocytes following lung transplant. Blood was collected from 18 stable lung transplant patients and 10 healthy age-matched controls. Intracellular pro-inflammatory cytokines and HAT/HDAC2 expression were determined in lymphocyte subsets following culture using flow cytometry. A loss of HDAC2 in cluster of differentiation (CD) 8+ T and NKT-like cells in transplant patients compared with controls was noted (CD8+ T: 28 ± 10 (45 ± 10), CD8+NKT-like: 30 ± 13 (54 ± 16) (mean ± SD transplant) (control)). Loss of HDAC2 was associated with an increased percentage of CD8+ T and NKT-like cells expressing perforin, granzyme b, interferon gamma (IFN-γ) and TNF-α (no change in HAT expression in any lymphocyte subset). There was a negative correlation between loss of HDAC2 expression by CD8+ T cells with cumulative dose of prednisolone and time post-transplant. Treatment with 10 mg/L theophylline + 1 µmol/L prednisolone or 2.5 ng/mL cyclosporine A synergistically upregulated HDAC2 and inhibited IFN-γ and TNF-α production by CD8+ T and NKT-like lymphocytes. HDAC2 is decreased in CD8+ T and NKT-like pro-inflammatory lymphocytes following lung transplant. Treatment options that increase HDAC2 may improve graft survival. © 2016 Asian Pacific Society of Respirology.

A mouse model of alcoholic liver fibrosis-associated acute kidney injury identifies key molecular pathways

International Nuclear Information System (INIS)

Furuya, Shinji; Chappell, Grace A.; Iwata, Yasuhiro; Uehara, Takeki; Kato, Yuki; Kono, Hiroshi; Bataller, Ramon; Rusyn, Ivan

2016-01-01

Clinical data strongly indicate that acute kidney injury (AKI) is a critical complication in alcoholic hepatitis, an acute-on-chronic form of liver failure in patients with advanced alcoholic fibrosis. Development of targeted therapies for AKI in this setting is hampered by the lack of an animal model. To enable research into molecular drivers and novel therapies for fibrosis- and alcohol-associated AKI, we aimed to combine carbon tetrachloride (CCl 4 )-induced fibrosis with chronic intra-gastric alcohol feeding. Male C57BL/6J mice were administered a low dose of CCl 4 (0.2 ml/kg 2 × week/6 weeks) followed by alcohol intragastrically (up to 25 g/kg/day for 3 weeks) and with continued CCl 4 . We observed that combined treatment with CCl 4 and alcohol resulted in severe liver injury, more pronounced than using each treatment alone. Importantly, severe kidney injury was evident only in the combined treatment group. This mouse model reproduced distinct pathological features consistent with AKI in human alcoholic hepatitis. Transcriptomic analysis of kidneys revealed profound effects in the combined treatment group, with enrichment for damage-associated pathways, such as apoptosis, inflammation, immune-response and hypoxia. Interestingly, Havcr1 and Lcn2, biomarkers of AKI, were markedly up-regulated. Overall, this study established a novel mouse model of fibrosis- and alcohol-associated AKI and identified key mechanistic pathways. - Highlights: • Acute kidney injury (AKI) is a critical complication in alcoholic hepatitis • We developed a novel mouse model of fibrosis- and alcohol-associated AKI • This model reproduces key molecular and pathological features of human AKI • This animal model can help identify new targeted therapies for alcoholic hepatitis

Alternative pathway for the development of Vα14+ NKT cells directly from CD4-CD8- thymocytes that bypasses the CD4+CD8+ stage.

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Dashtsoodol, Nyambayar; Shigeura, Tomokuni; Aihara, Minako; Ozawa, Ritsuko; Kojo, Satoshi; Harada, Michishige; Endo, Takaho A; Watanabe, Takashi; Ohara, Osamu; Taniguchi, Masaru

2017-03-01

Although invariant V α 14 + natural killer T cells (NKT cells) are thought to be generated from CD4 + CD8 + double-positive (DP) thymocytes, the developmental origin of CD4 - CD8 - double-negative (DN) NKT cells still remains unresolved. Here we provide definitive genetic evidence obtained, through studies of mice with DP-stage-specific ablation of expression of the gene encoding the recombinase component RAG-2 (Rag2) and by a fate-mapping approach, that supports the proposal of the existence of an alternative developmental pathway through which a fraction of DN NKT cells with strong T-helper-type-1 (T H 1)-biased and cytotoxic characteristics develop from late DN-stage thymocytes, bypassing the DP stage. These findings provide new insight into understanding of the development of NKT cells and propose a role for timing of expression of the invariant T cell antigen receptor in determining the functional properties of NKT cells.

Characterization of the subsets of human NKT-like cells and the expression of Th1/Th2 cytokines in patients with unexplained recurrent spontaneous abortion.

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Yuan, Jing; Li, Jian; Huang, Shi-Yun; Sun, Xin

2015-08-01

The objective was to investigate the subsets of natural killer T (NKT)-like cells and the expression of Th1/Th2 cytokines in the peripheral blood (PB) and/or decidual tissue of patients with unexplained recurrent spontaneous abortion (URSA). The percentages of NKT-like cells in the PB and deciduas of URSA patients in early pregnancy and in the PB of nonpregnant women were analyzed by flow cytometry. The expression of interferon (IFN)-γ (Th1 cytokine) and Th2 cytokines, interleukin (IL)-4 and IL-10, in the PB and decidual tissue was measured by quantitative RT-PCR and enzyme-linked immunosorbent assay (ELISA). Most percentages of subsets of NKT-like cells (CD3(+)CD56(+), CD3(+)CD56(+)CD16(+)) in the PB and deciduas were significantly greater in URSA patients than in normal pregnant and nonpregnant women. A cut-off value of 3.75% for the increased percentage of CD3(+)CD56(+)CD16(+) NKT-like cells in the PB appeared to be predictive of pregnancy failure. Moreover, we found that in the decidua, IFN-γ expression was significantly higher, while IL-4 and IL-10 expression was significantly lower in URSA patients compared with those with a normal pregnancy. The ratio of decidual Th1/Th2 cytokines in URSA patients was significantly increased compared with that in normal pregnant women. Decidual IL-4 expression correlated negatively with the percentages of blood CD3(+)CD56(+)CD16(+) NKT-like cells and the decidual CD3(+)CD56(+) and CD3(+)CD56(+)CD16(+) NKT-like cells. NKT-like cells may play an important role in maintaining normal pregnancy. Measurement of CD3(+)CD56(+)CD16(+) NKT-like cells in the PB may provide a potential tool for assessing patients' risk of spontaneous abortion. Copyright © 2015. Published by Elsevier Ireland Ltd.

Impact of associating liver partition and portal vein occlusion for staged hepatectomy on tumor growth in a mouse model of liver metastasis.

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Kikuchi, Yutaro; Hiroshima, Yukihiko; Matsuo, Kenichi; Murakami, Takashi; Kawaguchi, Daisuke; Kasahara, Kohei; Tanaka, Kuniya

2018-01-01

The impact of associating liver partition and portal vein occlusion for staged hepatectomy (ALPPS) on tumor growth activity was investigated. A BALB/c mouse model (male, 8-10 weeks old) of liver metastasis labeled by red fluorescent protein was established. Changes in future liver remnant (FLR) volumes, tumor growth activity, and levels of cytokines and growth factors in liver tissues during the treatment period were compared among the models involving ALPPS, portal vein ligation (PVL), or sham operation. The ratio of the FLR volume to body weight at 24 h after the procedure was greater for ALPPS (4.45 ± 0.12 × 10 -2 ) than for PVL (3.79 ± 0.12 × 10 -2 ; P = 0.003) and sham operation (3.18 ± 0.16 × 10 -2 ; P < 0.001). No differences in tumor progression in the FLR were observed at any time point after the procedures. Within the deportalized liver (DL), although tumor progression was observed during a later period after ALPPS (9 days postoperative) and PVL (12 days postoperative), no acceleration of tumor growth after ALPPS was observed in an early period similar to PVL. ALPPS induces a rapid increase in FLR volume and avoids remnant tumor progression during the early postoperative period. Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

IDH1 deficiency attenuates gluconeogenesis in mouse liver by impairing amino acid utilization.

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Ye, Jing; Gu, Yu; Zhang, Feng; Zhao, Yuanlin; Yuan, Yuan; Hao, Zhenyue; Sheng, Yi; Li, Wanda Y; Wakeham, Andrew; Cairns, Rob A; Mak, Tak W

2017-01-10

Although the enzymatic activity of isocitrate dehydrogenase 1 (IDH1) was defined decades ago, its functions in vivo are not yet fully understood. Cytosolic IDH1 converts isocitrate to α-ketoglutarate (α-KG), a key metabolite regulating nitrogen homeostasis in catabolic pathways. It was thought that IDH1 might enhance lipid biosynthesis in liver or adipose tissue by generating NADPH, but we show here that lipid contents are relatively unchanged in both IDH1-null mouse liver and IDH1-deficient HepG2 cells generated using the CRISPR-Cas9 system. Instead, we found that IDH1 is critical for liver amino acid (AA) utilization. Body weights of IDH1-null mice fed a high-protein diet (HPD) were abnormally low. After prolonged fasting, IDH1-null mice exhibited decreased blood glucose but elevated blood alanine and glycine compared with wild-type (WT) controls. Similarly, in IDH1-deficient HepG2 cells, glucose consumption was increased, but alanine utilization and levels of intracellular α-KG and glutamate were reduced. In IDH1-deficient primary hepatocytes, gluconeogenesis as well as production of ammonia and urea were decreased. In IDH1-deficient whole livers, expression levels of genes involved in AA metabolism were reduced, whereas those involved in gluconeogenesis were up-regulated. Thus, IDH1 is critical for AA utilization in vivo and its deficiency attenuates gluconeogenesis primarily by impairing α-KG-dependent transamination of glucogenic AAs such as alanine.

Proteome analysis of a hepatocyte-specific BIRC5 (survivin)-knockout mouse model during liver regeneration.

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Bracht, Thilo; Hagemann, Sascha; Loscha, Marius; Megger, Dominik A; Padden, Juliet; Eisenacher, Martin; Kuhlmann, Katja; Meyer, Helmut E; Baba, Hideo A; Sitek, Barbara

2014-06-06

The Baculoviral IAP repeat-containing protein 5 (BIRC5), also known as inhibitor of apoptosis protein survivin, is a member of the chromosomal passenger complex and a key player in mitosis. To investigate the function of BIRC5 in liver regeneration, we analyzed a hepatocyte-specific BIRC5-knockout mouse model using a quantitative label-free proteomics approach. Here, we present the analyses of the proteome changes in hepatocyte-specific BIRC5-knockout mice compared to wildtype mice, as well as proteome changes during liver regeneration induced by partial hepatectomy in wildtype mice and mice lacking hepatic BIRC5, respectively. The BIRC5-knockout mice showed an extensive overexpression of proteins related to cellular maintenance, organization and protein synthesis. Key regulators of cell growth, transcription and translation MTOR and STAT1/STAT2 were found to be overexpressed. During liver regeneration proteome changes representing a response to the mitotic stimulus were detected in wildtype mice. Mainly proteins corresponding to proliferation, cell cycle and cytokinesis were up-regulated. The hepatocyte-specific BIRC5-knockout mice showed impaired liver regeneration, which had severe consequences on the proteome level. However, several proteins with function in mitosis were found to be up-regulated upon the proliferative stimulus. Our results show that the E3 ubiquitin-protein ligase UHRF1 is strongly up-regulated during liver regeneration independently of BIRC5.

Establishment of a vascular endothelial cell-reactive type II NKT cell clone from a rat model of autoimmune vasculitis.

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Iinuma, Chihiro; Waki, Masashi; Kawakami, Ai; Yamaguchi, Madoka; Tomaru, Utano; Sasaki, Naomi; Masuda, Sakiko; Matsui, Yuki; Iwasaki, Sari; Baba, Tomohisa; Kasahara, Masanori; Yoshiki, Takashi; Paletta, Daniel; Herrmann, Thomas; Ishizu, Akihiro

2015-02-01

We previously generated a rat model that spontaneously developed small vessel vasculitis (SVV). In this study, a T cell clone reactive with rat vascular endothelial cells (REC) was established and named VASC-1. Intravenous injection of VASC-1 induced SVV in normal recipients. VASC-1 was a TCRαβ/CD3-positive CD4/CD8 double-negative T cell clone with expression of NKG2D. The cytokine mRNA profile under unstimulated condition was positive for IL-4 and IFN-γ but negative for IL-2 and IL-10. After interaction with REC, the mRNA expression of IL-2, IL-5 and IL-6 was induced in VASC-1, which was inhibited by blocking of CD1d on the REC surface. Although the protein levels of these cytokines seemed to be lower than the detection limit in the culture medium, IFN-γ was detectable. The production of IFN-γ from the VASC-1 stimulated with LPS-pre-treated REC was inhibited by the CD1d blockade on the REC. These findings indicated VASC-1 as an NKT cell clone. The NKT cell pool includes two major subsets, namely types I and II. Type I NKT cells are characterized by expression of semi-invariant TCRs and the potential to bind to marine sponge-derived α-galactosylceramide (α-GalCer) loaded on CD1d; whereas, type II NKT cells do not manifest these characteristics. VASC-1 exhibited a usage of TCR other than the type I invariant TCR α chain and did not bind to α-GalCer-loaded CD1d; therefore, it was determined as a type II NKT cell clone. The collective evidence suggested that REC-reactive type II NKT cells could be involved in the pathogenesis of SVV in rats. © The Japanese Society for Immunology. 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The mouse liver displays daily rhythms in the metabolism of phospholipids and in the activity of lipid synthesizing enzymes.

Science.gov (United States)

Gorné, Lucas D; Acosta-Rodríguez, Victoria A; Pasquaré, Susana J; Salvador, Gabriela A; Giusto, Norma M; Guido, Mario Eduardo

2015-02-01

The circadian system involves central and peripheral oscillators regulating temporally biochemical processes including lipid metabolism; their disruption leads to severe metabolic diseases (obesity, diabetes, etc). Here, we investigated the temporal regulation of glycerophospholipid (GPL) synthesis in mouse liver, a well-known peripheral oscillator. Mice were synchronized to a 12:12 h light-dark (LD) cycle and then released to constant darkness with food ad libitum. Livers collected at different times exhibited a daily rhythmicity in some individual GPL content with highest levels during the subjective day. The activity of GPL-synthesizing/remodeling enzymes: phosphatidate phosphohydrolase 1 (PAP-1/lipin) and lysophospholipid acyltransferases (LPLATs) also displayed significant variations, with higher levels during the subjective day and at dusk. We evaluated the temporal regulation of expression and activity of phosphatidylcholine (PC) synthesizing enzymes. PC is mainly synthesized through the Kennedy pathway with Choline Kinase (ChoK) as a key regulatory enzyme or through the phosphatidylethanolamine (PE) N-methyltransferase (PEMT) pathway. The PC/PE content ratio exhibited a daily variation with lowest levels at night, while ChoKα and PEMT mRNA expression displayed maximal levels at nocturnal phases. Our results demonstrate that mouse liver GPL metabolism oscillates rhythmically with a precise temporal control in the expression and/or activity of specific enzymes.

TRAF2 regulates peripheral CD8(+) T-cell and NKT-cell homeostasis by modulating sensitivity to IL-15.

Science.gov (United States)

Villanueva, Jeanette E; Malle, Elisabeth K; Gardam, Sandra; Silveira, Pablo A; Zammit, Nathan W; Walters, Stacey N; Brink, Robert; Grey, Shane T

2015-06-01

In this study, a critical and novel role for TNF receptor (TNFR) associated factor 2 (TRAF2) is elucidated for peripheral CD8(+) T-cell and NKT-cell homeostasis. Mice deficient in TRAF2 only in their T cells (TRAF2TKO) show ∼40% reduction in effector memory and ∼50% reduction in naïve CD8(+) T-cell subsets. IL-15-dependent populations were reduced further, as TRAF2TKO mice displayed a marked ∼70% reduction in central memory CD8(+) CD44(hi) CD122(+) T cells and ∼80% decrease in NKT cells. TRAF2TKO CD8(+) CD44(hi) T cells exhibited impaired dose-dependent proliferation to exogenous IL-15. In contrast, TRAF2TKO CD8(+) T cells proliferated normally to anti-CD3 and TRAF2TKO CD8(+) CD44(hi) T cells exhibited normal proliferation to exogenous IL-2. TRAF2TKO CD8(+) T cells expressed normal levels of IL-15-associated receptors and possessed functional IL-15-mediated STAT5 phosphorylation, however TRAF2 deletion caused increased AKT activation. Loss of CD8(+) CD44(hi) CD122(+) and NKT cells was mechanistically linked to an inability to respond to IL-15. The reduced CD8(+) CD44(hi) CD122(+) T-cell and NKT-cell populations in TRAF2TKO mice were rescued in the presence of high dose IL-15 by IL-15/IL-15Rα complex administration. These studies demonstrate a critical role for TRAF2 in the maintenance of peripheral CD8(+) CD44(hi) CD122(+) T-cell and NKT-cell homeostasis by modulating sensitivity to T-cell intrinsic growth factors such as IL-15. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A mouse model of alcoholic liver fibrosis-associated acute kidney injury identifies key molecular pathways

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Furuya, Shinji; Chappell, Grace A.; Iwata, Yasuhiro [Department of Veterinary Integrative Biosciences, Texas A& M University, College Station, TX (United States); Uehara, Takeki; Kato, Yuki [Laboratory of Veterinary Pathology, Osaka Prefecture University, Osaka (Japan); Kono, Hiroshi [First Department of Surgery, University of Yamanashi, Yamanashi (Japan); Bataller, Ramon [Division of Gastroenterology & Hepatology, Department of Medicine, University of North Carolina, Chapel Hill, NC (United States); Rusyn, Ivan, E-mail: irusyn@tamu.edu [Department of Veterinary Integrative Biosciences, Texas A& M University, College Station, TX (United States)

2016-11-01

Clinical data strongly indicate that acute kidney injury (AKI) is a critical complication in alcoholic hepatitis, an acute-on-chronic form of liver failure in patients with advanced alcoholic fibrosis. Development of targeted therapies for AKI in this setting is hampered by the lack of an animal model. To enable research into molecular drivers and novel therapies for fibrosis- and alcohol-associated AKI, we aimed to combine carbon tetrachloride (CCl{sub 4})-induced fibrosis with chronic intra-gastric alcohol feeding. Male C57BL/6J mice were administered a low dose of CCl{sub 4} (0.2 ml/kg 2 × week/6 weeks) followed by alcohol intragastrically (up to 25 g/kg/day for 3 weeks) and with continued CCl{sub 4}. We observed that combined treatment with CCl{sub 4} and alcohol resulted in severe liver injury, more pronounced than using each treatment alone. Importantly, severe kidney injury was evident only in the combined treatment group. This mouse model reproduced distinct pathological features consistent with AKI in human alcoholic hepatitis. Transcriptomic analysis of kidneys revealed profound effects in the combined treatment group, with enrichment for damage-associated pathways, such as apoptosis, inflammation, immune-response and hypoxia. Interestingly, Havcr1 and Lcn2, biomarkers of AKI, were markedly up-regulated. Overall, this study established a novel mouse model of fibrosis- and alcohol-associated AKI and identified key mechanistic pathways. - Highlights: • Acute kidney injury (AKI) is a critical complication in alcoholic hepatitis • We developed a novel mouse model of fibrosis- and alcohol-associated AKI • This model reproduces key molecular and pathological features of human AKI • This animal model can help identify new targeted therapies for alcoholic hepatitis.

Bcl-xL regulates CD1d-mediated antigen presentation to NKT cells by altering CD1d trafficking through the endocytic pathway.

Science.gov (United States)

Subrahmanyam, Priyanka B; Carey, Gregory B; Webb, Tonya J

2014-09-01

NKT cells are a unique subset of T cells that recognize glycolipid Ags presented in the context of CD1d molecules. NKT cells mount strong antitumor responses and are a major focus in developing effective cancer immunotherapy. It is known that CD1d molecules are constantly internalized from the cell surface, recycled through the endocytic compartments, and re-expressed on the cell surface. However, little is known about the regulation of CD1d-mediated Ag processing and presentation in B cell lymphoma. Prosurvival factors of the Bcl-2 family, such as Bcl-xL, are often upregulated in B cell lymphomas and are intimately linked to sphingolipid metabolism, as well as the endocytic compartments. We hypothesized that Bcl-xL can regulate CD1d-mediated Ag presentation to NKT cells. We found that overexpression or induction of Bcl-xL led to increased Ag presentation to NKT cells. Conversely, the inhibition or knockdown of Bcl-xL led to decreased NKT cell activation. Furthermore, knockdown of Bcl-xL resulted in the loss of CD1d trafficking to lysosome-associated membrane protein 1(+) compartments. Rab7, a late endosomal protein, was upregulated and CD1d molecules accumulated in the Rab7(+) late endosomal compartment. These results demonstrate that Bcl-xL regulates CD1d-mediated Ag processing and presentation to NKT cells by altering the late endosomal compartment and changing the intracellular localization of CD1d. Copyright © 2014 by The American Association of Immunologists, Inc.

Mouse precision-cut liver slices as an ex vivo model to study idiosyncratic drug-induced liver injury.

Science.gov (United States)

Hadi, Mackenzie; Chen, Yixi; Starokozhko, Viktoriia; Merema, Marjolijn T; Groothuis, Geny M M

2012-09-17

Idiosyncratic drug-induced liver injury (IDILI) has been the top reason for withdrawing drugs from the market or for black box warnings. IDILI may arise from the interaction of a drug's reactive metabolite with a mild inflammation that renders the liver more sensitive to injury resulting in increased toxicity (inflammatory stress hypothesis). Aiming to develop a robust ex vivo screening method to study inflammatory stress-related IDILI mechanisms and to find biomarkers that can detect or predict IDILI, mouse precision-cut liver slices (mPCLS) were coincubated for 24 h with IDILI-related drugs and lipopolysaccharide. Lipopolysaccharide exacerbated ketoconazole (15 μM) and clozapine (45 μM) toxicity but not their non-IDILI-related comparators, voriconazole (1500 μM) and olanzapine (45 μM). However, the other IDILI-related drugs tested [diclofenac (200 μM), carbamazepine (400 μM), and troglitazone (30 μM)] did not cause synergistic toxicity with lipopolysaccharide after 24 h of incubation. Lipopolysaccharide further decreased the reduced glutathione levels caused by ketoconazole or clozapine in mPCLS after 24 h of incubation, which was not the case for the other drugs. Lipopolysaccharide significantly increased nitric oxide (NO), cytokine, and chemokine release into the mPCLS media, while the treatment with the drugs alone did not cause any substantial change. All seven drugs drastically reduced lipopolysaccharide-induced NO production. Interestingly, only ketoconazole and clozapine increased the lipopolysaccharide-induced granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) release. Pilot experiments showed that diclofenac and troglitazone, but not carbamazepine, demonstrated synergistic toxicity with lipopolysaccharide after a longer incubation of 48 h in mPCLS. In conclusion, we have developed an ex vivo model to detect inflammatory stress-related liver toxicity and identified ketoconazole, clozapine

Microarray data reveal relationship between Jag1 and Ddr1 in mouse liver.

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Lara A Underkoffler

Full Text Available Alagille syndrome is an autosomal dominant disorder involving bile duct paucity and cholestasis in addition to cardiac, skeletal, ophthalmologic, renal and vascular manifestations. Mutations in JAG1, encoding a ligand in the Notch signaling pathway, are found in 95% of patients meeting clinical criteria for Alagille syndrome. In order to define the role of Jag1 in the bile duct developmental abnormalities seen in ALGS, we previously created a Jag1 conditional knockout mouse model. Mice heterozygous for the Jag1 conditional and null alleles demonstrate abnormalities in postnatal bile duct growth and remodeling, with portal expansion and increased numbers of malformed bile ducts. In this study we report the results of microarray analysis and identify genes and pathways differentially expressed in the Jag1 conditional/null livers as compared with littermate controls. In the initial microarray analysis, we found that many of the genes up-regulated in the Jag1 conditional/null mutant livers were related to extracellular matrix (ECM interactions, cell adhesion and cell migration. One of the most highly up-regulated genes was Ddr1, encoding a receptor tyrosine kinase (RTK belonging to a large RTK family. We have found extensive co-localization of Jag1 and Ddr1 in bile ducts and blood vessels in postnatal liver. In addition, co-immunoprecipitation data provide evidence for a novel protein interaction between Jag1 and Ddr1. Further studies will be required to define the nature of this interaction and its functional consequences, which may have significant implications for bile duct remodeling and repair of liver injury.

Silymarin attenuated hepatic steatosis through regulation of lipid metabolism and oxidative stress in a mouse model of nonalcoholic fatty liver disease (NAFLD).

Science.gov (United States)

Ni, Xunjun; Wang, Haiyan

2016-01-01

Silymarin, which derived from the milk thistle plant (silybum marianum), has been used for centuries as a natural remedy for diseases of the liver and biliary tract. Considering the therapeutic potential to liver disease, we tested efficacy of silymarin on hepatic steatosis with a high fat diet (HFD)-induced mouse model of non-alcoholic fatty liver disease (NAFLD), and investigated possible effects on lipid metabolic pathways. In our study, silymarin could attenuate the hepatic steatosis, which was proved by both Oil Red O staining and hepatic triglyceride (TG) level determination. Furthermore, compared with INT-747, a potent and selective FXR agonist, silymarin could preserve plasmatic high-density lipoprotein cholesterol (HDL-C) to a higher level and low-density lipoprotein cholesterol (LDL-C) to a lower level, which benefited more to the circulation system. Through real-time PCR analysis, we clarified a vital protective role of silymarin in mRNA regulation of genes involved in lipid metabolism and oxidative stress. It was also shown that silymarin had no effects on body weight, food intake, and liver transaminase. Taken together, silymarin could attenuate hepatic steatosis in a mouse model of NAFLD through regulation of lipid metabolism and oxidative stress, and benefit to the circulation system. All these findings shed new light on NAFLD treatment.

NKT cells can help mediate the protective effects of 1,25-dihydroxyvitamin D3 in experimental autoimmune encephalomyelitis in mice.

Science.gov (United States)

Waddell, Amanda; Zhao, Jun; Cantorna, Margherita T

2015-05-01

Active vitamin D [1,25-dihydroxyvitamin D3 (1,25D3)] blocks the development of experimental autoimmune diseases. However, the molecular and immunobiological mechanisms underlying 1,25D3's anti-inflammatory properties are not fully understood. We employed a murine model of experimental autoimmune encephalomyelitis (EAE) in order to determine the role of NKT cells in 1,25D3-mediated protection from EAE. Wild-type (WT) mice or mice lacking all NKT cells (CD1d(-/-)) or invariant NKT cells (Jα18(-/-)) were fed control or 1,25D3-supplemented diets. All mice fed with the control diet developed severe EAE. 1,25D3 treatment of WT mice protected them from developing EAE. CD1d(-/-) and Jα18(-/-) mice treated with 1,25D3 were not protected to the same extent as WT mice. Myelin oligodendrocyte glycoprotein-specific IL-17 and IFN-γ production was significantly reduced in 1,25D3 WT mice compared with WT but was not decreased in 1,25D3 CD1d(-/-) mice compared with CD1d(-/-) mice. IL-4(-/-) mice were utilized to determine how IL-4 deficiency affects susceptibility to EAE. IL-4(-/-) mice were not protected from developing EAE by α-galactosylceramide (α-GalCer) or 1,25D3 treatment. Furthermore, 1,25D3 treatment of splenocytes in vitro decreased α-GalCer-induced IL-17 and increased IL-4, IL-5 and IL-10 production. 1,25D3 alters the cytokine profile of invariant NKT cells in vitro. These studies demonstrate that NKT cells are important mediators of 1,25D3-induced protection from EAE in mice and NKT cell-derived IL-4 may be an important factor in providing this protection. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Usage of adenovirus expressing thymidine kinase mediated hepatocellular damage for enabling mouse liver repopulation with allogenic or xenogenic hepatocytes.

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Daniel Moreno

Full Text Available It has been shown that the liver of immunodeficient mice can be efficiently repopulated with human hepatocytes when subjected to chronic hepatocellular damage. Mice with such chimeric livers represent useful reagents for medical and clinical studies. However all previously reported models of humanized livers are difficult to implement as they involve cross-breeding of immunodeficient mice with mice exhibiting genetic alterations causing sustained hepatic injury. In this paper we attempted to create chimeric livers by inducing persistent hepatocellular damage in immunodeficient Rag2(-/- γc(-/- mice using an adenovirus encoding herpes virus thymidine kinase (AdTk and two consecutive doses of ganciclovir (GCV. We found that this treatment resulted in hepatocellular damage persisting for at least 10 weeks and enabled efficient engraftment and proliferation within the liver of either human or allogenic hepatocytes. Interestingly, while the nodules generated from the transplanted mouse hepatocytes were well vascularized, the human hepatocytes experienced progressive depolarization and exhibited reduced numbers of murine endothelial cells inside the nodules. In conclusion, AdTk/GCV-induced liver damage licenses the liver of immunodeficient mice for allogenic and xenogenic hepatocyte repopulation. This approach represents a simple alternative strategy for chimeric liver generation using immunodeficient mice without additional genetic manipulation of the germ line.

Obstructive Sleep Apnea and Non-alcoholic Fatty Liver Disease: Is the Liver Another Target?

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Aibek eMirrakhimov

2012-10-01

Full Text Available Obstructive sleep apnea (OSA is recurrent obstruction of the upper airway during sleep leading to intermittent hypoxia (IH. OSA has been associated with all components of the metabolic syndrome as well as with non-alcoholic fatty liver disease (NAFLD. NAFLD is a common condition ranging in severity from uncomplicated hepatic steatosis to steatohepatitis (NASH, liver fibrosis and cirrhosis. The gold standard for the diagnosis and staging of NAFLD is liver biopsy. Obesity and insulin resistance lead to liver steatosis, but the causes of the progression to NASH are not known. Emerging evidence suggests that OSA may play a role in the progression of hepatic steatosis and the development of NASH. Several cross-sectional studies showed that the severity of IH in patients with OSA predicted the severity of NAFLD on liver biopsy. However, neither prospective nor interventional studies with continuous positive airway pressure (CPAP treatment have been performed. Studies in a mouse model showed that IH causes triglyceride accumulation in the liver and liver injury as well as hepatic inflammation. The mouse model provided insight in the pathogenesis of liver injury showing that (1 IH accelerates the progression of hepatic steatosis by inducing adipose tissue lipolysis and increasing free fatty acids (FFA flux into the liver; (2 IH up-regulates lipid biosynthetic pathways in the liver; (3 IH induces oxidative stress in the liver; (4 IH up-regulates hypoxia inducible factor 1 alpha and possibly HIF-2 alpha, which may increase hepatic steatosis and induce liver inflammation and fibrosis. However, the role of FFA and different transcription factors in the pathogenesis of IH-induced NAFLD is yet to be established. Thus, multiple lines of evidence suggest that IH of OSA may contribute to the progression of NAFLD but definitive clinical studies and experiments in the mouse model have yet to be done.

CD1d-restricted IFN-γ-secreting NKT cells promote immune complex-induced acute lung injury by regulating macrophage-inflammatory protein-1α production and activation of macrophages and dendritic cells.

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Kim, Ji Hyung; Chung, Doo Hyun

2011-02-01

Immune complex-induced acute lung injury (IC-ALI) has been implicated in various pulmonary disease states. However, the role of NKT cells in IC-ALI remains unknown. Therefore, we explored NKT cell functions in IC-ALI using chicken egg albumin and anti-chicken egg albumin IgG. The bronchoalveolar lavage fluid of CD1d(-/-) and Jα18(-/-) mice contained few Ly6G(+)CD11b(+) granulocytes, whereas levels in B6 mice were greater and were increased further by α-galactosyl ceramide. IFN-γ and MIP-1α production in the lungs was greater in B6 than CD1d(-/-) mice. Adoptive transfer of wild type (WT) but not IFN-γ-, MIP-1α-, or FcγR-deficient NKT cells into CD1d(-/-) mice caused recruitment of inflammatory cells to the lungs. Moreover, adoptive transfer of IFN-γR-deficient NKT cells enhanced MIP-1α production and cell recruitment in the lungs of CD1d(-/-) or CD1d(-/-)IFN-γ(-/-) mice, but to a lesser extent than WT NKT cells. This suggests that IFN-γ-producing NKT cells enhance MIP-1α production in both an autocrine and a paracrine manner. IFN-γ-deficient NKT cells induced less IL-1β and TNF-α production by alveolar macrophages and dendritic cells in CD1d(-/-) mice than did WT NKT cells. Taken together, these data suggest that CD1d-restricted IFN-γ-producing NKT cells promote IC-ALI by producing MIP-1α and enhancing proinflammatory cytokine production by alveolar macrophages and dendritic cells.

The feasibility research of galactosyl-anti-mouse CD3 monoclonal antibody being used as carrier of immunotherapy after surgical operation of liver cancer

International Nuclear Information System (INIS)

Li Yunchun; Guan Changtian; Yang Xiaochuan; He Sheng; Jiang Ping; Yuan Lin

2000-01-01

Objective: To probe into the feasibility of galactosyl-anti-mouse CD 3 monoclonal antibody (Gal-Ant-CD 3 McAb) being used as carrier of immunotherapy after surgical operation of liver cancer. Methods: Gal-Ant-CD 3 McAb was prepared by the covalent coupling of anti-mouse CD 3 monoclonal antibody (Ant-CD 3 McAb) with a bifunctional reagent, 2-imino-2-methoxyethyl-1-thio-galactose. After Gal-Ant-CD 3 McAb and Ant-CD 3 McAb were labelled with 131 I or 125 I, the data of biodistribution in mice, and of imaging in rabbit were obtained. After tumour infiltrating lymphocytes (TIL) and Gal-Ant-CD 3 McAb were coupled into Gal-Ant-CD 3 McAb-TIL, its liver taxis and cytotoxic activity against autologous cancer cells were measured in vitro. Results: Gal-Ant-CD 3 McAb had remarkable livertaxis and its uptake in per gram liver was (59.0 +- 2.1)% that was more than two-fold higher than that of Ant-CD 3 McAb. Gal-Ant-CD 3 McAb-TIL had an obvious liver taxis and cytotoxic activity against autologous cancer cells in vitro. Conclusion: Gal-Ant-CD 3 McAb can be used as the carrier of immunotherapy after surgical operation of liver cancer

Group 2 innate lymphoid cell production of IL-5 is regulated by NKT cells during influenza virus infection.

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Stacey Ann Gorski

2013-09-01

Full Text Available Respiratory virus infections, such as influenza, typically induce a robust type I (pro-inflammatory cytokine immune response, however, the production of type 2 cytokines has been observed. Type 2 cytokine production during respiratory virus infection is linked to asthma exacerbation; however, type 2 cytokines may also be tissue protective. Interleukin (IL-5 is a prototypical type 2 cytokine that is essential for eosinophil maturation and egress out of the bone marrow. However, little is known about the cellular source and underlying cellular and molecular basis for the regulation of IL-5 production during respiratory virus infection. Using a mouse model of influenza virus infection, we found a robust transient release of IL-5 into infected airways along with a significant and progressive accumulation of eosinophils into the lungs, particularly during the recovery phase of infection, i.e. following virus clearance. The cellular source of the IL-5 was group 2 innate lymphoid cells (ILC2 infiltrating the infected lungs. Interestingly, the progressive accumulation of eosinophils following virus clearance is reflected in the rapid expansion of c-kit⁺ IL-5 producing ILC2. We further demonstrate that the enhanced capacity for IL-5 production by ILC2 during recovery is concomitant with the enhanced expression of the IL-33 receptor subunit, ST2, by ILC2. Lastly, we show that NKT cells, as well as alveolar macrophages (AM, are endogenous sources of IL-33 that enhance IL-5 production from ILC2. Collectively, these results reveal that c-kit⁺ ILC2 interaction with IL-33 producing NKT and AM leads to abundant production of IL-5 by ILC2 and accounts for the accumulation of eosinophils observed during the recovery phase of influenza infection.

The Metabolism of Separase Inhibitor Sepin-1 in Human, Mouse, and Rat Liver Microsomes

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Feng Li

2018-05-01

Full Text Available Separase, a known oncogene, is widely overexpressed in numerous human tumors of breast, bone, brain, blood, and prostate. Separase is an emerging target for cancer therapy, and separase enzymatic inhibitors such as sepin-1 are currently being developed to treat separase-overexpressed tumors. Drug metabolism plays a critical role in the efficacy and safety of drug development, as well as possible drug–drug interactions. In this study, we investigated the in vitro metabolism of sepin-1 in human, mouse, and rat liver microsomes (RLM using metabolomic approaches. In human liver microsomes (HLM, we identified seven metabolites including one cysteine–sepin-1 adduct and one glutathione–sepin-1 adduct. All the sepin-1 metabolites in HLM were also found in both mouse and RLM. Using recombinant CYP450 isoenzymes, we demonstrated that multiple enzymes contributed to the metabolism of sepin-1, including CYP2D6 and CYP3A4 as the major metabolizing enzymes. Inhibitory effects of sepin-1 on seven major CYP450s were also evaluated using the corresponding substrates recommended by the US Food and Drug Administration. Our studies indicated that sepin-1 moderately inhibits CYP1A2, CYP2C19, and CYP3A4 with IC50 < 10 μM but weakly inhibits CYP2B6, CYP2C8/9, and CYP2D6 with IC50 > 10 μM. This information can be used to optimize the structures of sepin-1 for more suitable pharmacological properties and to predict the possible sepin-1 interactions with other chemotherapeutic drugs.

Modification of nanocellulose by poly-lysine can inhibit the effect of fumonisin B1 on mouse liver cells.

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Jebali, Ali; Yasini Ardakani, Seyed Ali; Shahdadi, Hossein; Balal Zadeh, Mohammad Hossein; Hekmatimoghaddam, Seyedhossein

2015-02-01

Fumonisin B1 is an important mycotoxin, mainly produced by Fusarium verticillioides. It has toxic effects on liver, brain, and kidney cells. The first aim of this study was to synthesize nanocellulose modified with poly-lysine (NMPL), and the second aim was to evaluate the adsorption of fumonisin B1 by NMPL. As third aim, the function of mouse liver cells was investigated after exposure to fumonisin B1, and fumonisin B1+ NMPL. In this study, NMPL was prepared using cross-linker, and then incubated with fumonisin B1 at controlled conditions. After incubation, the adsorption and release of fumonisin B1 were evaluated in each condition. Next, mouse liver cells were separately exposed to fumonisin B1, NMPL, and (fumonisin B1+NMPL). Then, the level of aniline aminotransferase (ALT) and aspartate aminotransferase (AST) was evaluated. It was found that both adsorption and release of fumonisin B1 were not affected by temperature and incubation time, but affected by pH and concentration of NMPL. Also, this study showed NMPL could adsorb fumonisin B1 in different foodstuffs. Importantly, although the levels of ALT and AST were increased when the cells were treated with fumonisin B1 alone, they were not affected when exposed to NMPL or (fumonisin B1+NMPL). The authors suggest that NMPL is a good adsorbent to remove and inhibit fumonisin B1. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of the subcellular distribution of monomeric 239Pu and 59Fe in the liver of rat, mouse, and Syrian and Chinese hamsters

International Nuclear Information System (INIS)

Winter, R.; Seidel, A.

1982-01-01

The subcellular distribution of 239 Pu and 59 Fe 10 days after intravenous injection as a citrate complex was investigated by sucrose density gradient centrifugation in the liver of rat, mouse, and Syrian and Chinese hamsters. Lysosomes were separated from other cell constituents by injection of the nonionic detergent Triton WR 1339 4 days before sacrifice. The Triton-induced decrease in the density of the lysosomes was very similar in all four animal species and was followed closely by a corresponding decrease of the median density of the 239 Pu profiles in rat, mouse, and, to a smaller extent, Syrian hamster. However, in Chinese hamster a clear correspondence between lysosomes and 239 Pu was not found 10 days after nuclide injection. It was concluded that lysosomes are the main storage organelles fo 239 Pu in the liver of rat and mouse and that in all four animal species mitochondria and endoplasmic reticulum do not play any significant role in binding the radionuclide. The relevance of pericellular membranes has to be checked. The distribution patterns of 59 Fe and 239 Pu were quite different

Mice lacking natural killer T cells are more susceptible to metabolic alterations following high fat diet feeding.

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Brittany V Martin-Murphy

Full Text Available Current estimates suggest that over one-third of the adult population has metabolic syndrome and three-fourths of the obese population has non-alcoholic fatty liver disease (NAFLD. Inflammation in metabolic tissues has emerged as a universal feature of obesity and its co-morbidities, including NAFLD. Natural Killer T (NKT cells are a subset of innate immune cells that abundantly reside within the liver and are readily activated by lipid antigens. There is general consensus that NKT cells are pivotal regulators of inflammation; however, disagreement exists as to whether NKT cells exert pathogenic or suppressive functions in obesity. Here we demonstrate that CD1d(-/- mice, which lack NKT cells, were more susceptible to weight gain and fatty liver following high fat diet (HFD feeding. Compared with their WT counterparts, CD1d(-/- mice displayed increased adiposity and greater induction of inflammatory genes in the liver suggestive of the precursors of NAFLD. Calorimetry studies revealed a significant increase in food intake and trends toward decreased metabolic rate and activity in CD1d(-/- mice compared with WT mice. Based on these findings, our results suggest that NKT cells play a regulatory role that helps to prevent diet-induced obesity and metabolic dysfunction and may play an important role in mechanisms governing cross-talk between metabolism and the immune system to regulate energy balance and liver health.

Effect of diphenyl ether herbicides and oxadiazon on porphyrin biosynthesis in mouse liver, rat primary hepatocyte culture and HepG2 cells.

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Krijt, J; van Holsteijn, I; Hassing, I; Vokurka, M; Blaauboer, B J

1993-01-01

The effects of the herbicides fomesafen, oxyfluorfen, oxadiazon and fluazifop-butyl on porphyrin accumulation in mouse liver, rat primary hepatocyte culture and HepG2 cells were investigated. Ten days of herbicide feeding (0.25% in the diet) increased the liver porphyrins in male C57B1/6J mice from 1.4 +/- 0.6 to 4.8 +/- 2.1 (fomesafen) 16.9 +2- 2.9 (oxyfluorfen) and 25.9 +/- 3.1 (oxadiazon) nmol/g wet weight, respectively. Fluazifop-butyl had no effect on liver porphyrin metabolism. Fomesafen, oxyfluorfen and oxadiazon increased the cellular porphyrin content of rat hepatocytes after 24 h of incubation (control, 3.2 pmol/mg protein, fomesafen, oxyfluorfen and oxadiazon at 0.125 mM concentration 51.5, 54.3 and 44.0 pmol/mg protein, respectively). The porphyrin content of HepG2 cells increased from 1.6 to 18.2, 10.6 and 9.2 pmol/mg protein after 24 h incubation with the three herbicides. Fluazifop-butyl increased hepatic cytochrome P450 levels and ethoxy- and pentoxyresorufin O-dealkylase (EROD and PROD) activity, oxyfluorfen increased PROD activity. Peroxisomal palmitoyl CoA oxidation increased after fomesafen and fluazifop treatment to about 500% of control values both in mouse liver and rat hepatocytes. Both rat hepatocytes and HepG2 cells can be used as a test system for the porphyrogenic potential of photobleaching herbicides.

Binding of Cimetidine to Balb/C Mouse Liver Catalase; Kinetics and Conformational Studies.

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Jahangirvand, Mahboubeh; Minai-Tehrani, Dariush; Yazdi, Fatemeh; Minai-Tehrani, Arash; Razmi, Nematollah

2016-01-01

Catalase is responsible for converting hydrogen peroxide (H2O2) into water and oxygen in cells. This enzyme has high affinity for hydrogen peroxide and can protect the cells from oxidative stress damage. Catalase is a tetramer protein and each monomer contains a heme group. Cimetidine is a histamine H2 receptor blocker which inhibits acid release from stomach and is used for gasterointestinal diseases. In this research, effect of cimetidine on the activity of liver catalase was studied and the kinetic parameters of this enzyme and its conformational changes were investigated. Cell free extract of mouse liver was used for the catalase assay. The activity of the catalase was detected in the absence and presence of cimetidine by monitoring hydrogen peroxide reduction absorbance at 240 nm. The purified enzyme was used for conformational studies by Fluorescence spectrophotometry. The data showed that cimetidine could inhibit the enzyme in a non-competitive manner. Ki and IC50 values of the drug were determined to be about 0.75 and 0.85 uM, respectively. The Arrhenius plot showed that activation energy was 6.68 and 4.77 kJ/mol in the presence and absence of the drug, respectively. Fluorescence spectrophotometry revealed that the binding of cimetidine to the purified enzyme induced hyperchromicity and red shift which determined the conformational change on the enzyme. Cimetidine could non-competitively inhibit the liver catalase with high affinity. Binding of cimetidine to the enzyme induced conformational alteration in the enzyme.

NK and NKT Cell Depletion Alters the Outcome of Experimental Pneumococcal Pneumonia: Relationship with Regulation of Interferon-γ Production

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Eirini Christaki

2015-01-01

Full Text Available Background. Natural killer (NK and natural killer T (NKT cells contribute to the innate host defense but their role in bacterial sepsis remains controversial. Methods. C57BL/6 mice were infected intratracheally with 5 × 105 cfu of Streptococcus pneumoniae. Animals were divided into sham group (Sham; pretreated with isotype control antibody (CON group; pretreated with anti-asialo GM1 antibody (NKd group; and pretreated with anti-CD1d monoclonal antibody (NKTd group before bacterial challenge. Serum and tissue samples were analyzed for bacterial load, cytokine levels, splenocyte apoptosis rates, and cell characteristics by flow cytometry. Splenocyte miRNA expression was also analyzed and survival was assessed. Results. NK cell depletion prolonged survival. Upon inhibition of NKT cell activation, spleen NK (CD3−/NK1.1+ cells increased compared to all other groups. Inhibition of NKT cell activation led to higher bacterial loads and increased levels of serum and splenocyte IFN-γ. Splenocyte miRNA analysis showed that miR-200c and miR-29a were downregulated, while miR-125a-5p was upregulated, in anti-CD1d treated animals. These changes were moderate after NK cell depletion. Conclusions. NK cells appear to contribute to mortality in pneumococcal pneumonia. Inhibition of NKT cell activation resulted in an increase in spleen NK (CD3−/NK1.1+ cells and a higher IFN-γ production, while altering splenocyte miRNA expression.

Ly108 expression distinguishes subsets of invariant NKT cells that help autoantibody production and secrete IL-21 from those that secrete IL-17 in lupus prone NZB/W mice.

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Tang, Xiaobin; Zhang, Bo; Jarrell, Justin A; Price, Jordan V; Dai, Hongjie; Utz, Paul J; Strober, Samuel

2014-05-01

Lupus is a systemic autoimmune disease characterized by anti-nuclear antibodies in humans and genetically susceptible NZB/W mice that can cause immune complex glomerulonephritis. T cells contribute to lupus pathogenesis by secreting pro-inflammatory cytokines such as IL-17, and by interacting with B cells and secreting helper factors such as IL-21 that promote production of IgG autoantibodies. In the current study, we determined whether purified NKT cells or far more numerous conventional non-NKT cells in the spleen of NZB/W female mice secrete IL-17 and/or IL-21 after TCR activation in vitro, and provide help for spontaneous IgG autoantibody production by purified splenic CD19(+) B cells. Whereas invariant NKT cells secreted large amounts of IL-17 and IL-21, and helped B cells, non-NKT cells did not. The subset of IL-17 secreting NZB/W NKT cells expressed the Ly108(lo)CD4(-)NK1.1(-) phenotype, whereas the IL-21 secreting subset expressed the Ly108(hi)CD4(+)NK1.1(-) phenotype and helped B cells secrete a variety of IgG anti-nuclear antibodies. α-galactocylceramide enhanced the helper activity of NZB/W and B6.Sle1b NKT cells for IgG autoantibody secretion by syngeneic B cells. In conclusion, different subsets of iNKT cells from mice with genetic susceptibility to lupus can contribute to pathogenesis by secreting pro-inflammatory cytokines and helping autoantibody production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spaceflight Activates Lipotoxic Pathways in Mouse Liver.

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Karen R Jonscher

Full Text Available Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease.

Spaceflight Activates Lipotoxic Pathways in Mouse Liver

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Jonscher, Karen R.; Alfonso-Garcia, Alba; Suhalim, Jeffrey L.; Orlicky, David J.; Potma, Eric O.; Ferguson, Virginia L.; Bouxsein, Mary L.; Bateman, Ted A.; Stodieck, Louis S.; Levi, Moshe; Friedman, Jacob E.; Gridley, Daila S.; Pecaut, Michael J.

2016-01-01

Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease. PMID:27097220

Metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, in mouse liver by alcohol dehydrogenase Adh1 and aldehyde reductase AKR1A4

International Nuclear Information System (INIS)

Short, Duncan M.; Lyon, Robert; Watson, David G.; Barski, Oleg A.; McGarvie, Gail; Ellis, Elizabeth M.

2006-01-01

The reductive metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, was studied in mouse liver. Using an HPLC-based stopped assay, the primary reduced metabolite was identified as 6-hydroxy-trans, trans-2,4-hexadienal (OH/CHO) and the secondary metabolite as 1,6-dihydroxy-trans, trans-2,4-hexadiene (OH/OH). The main enzymes responsible for the highest levels of reductase activity towards trans, trans-muconaldehyde were purified from mouse liver soluble fraction first by Q-sepharose chromatography followed by either blue or red dye affinity chromatography. In mouse liver, trans, trans-muconaldehyde is predominantly reduced by an NADH-dependent enzyme, which was identified as alcohol dehydrogenase (Adh1). Kinetic constants obtained for trans, trans-muconaldehyde with the native Adh1 enzyme showed a V max of 2141 ± 500 nmol/min/mg and a K m of 11 ± 4 μM. This enzyme was inhibited by pyrazole with a K I of 3.1 ± 0.57 μM. Other fractions were found to contain muconaldehyde reductase activity independent of Adh1, and one enzyme was identified as the NADPH-dependent aldehyde reductase AKR1A4. This showed a V max of 115 nmol/min/mg and a K m of 15 ± 2 μM and was not inhibited by pyrazole

Formation of DNA adducts in mouse tissues after 1-nitropyrene administration

International Nuclear Information System (INIS)

Mitchell, C.E.

1986-01-01

DNA adducts were isolated and characterized in mouse lung, liver and kidney after intratracheal instillation of [ 3 H]-1-nitropyrene (1-NP). HPLC analysis of the enzymatically digested DNA indicated the presence of multiple DNA adducts in mouse lung, liver and kidney. These results indicate that DNA adducts of 1-NP are formed in mouse lung, liver and kidney after intratracheal instillation of 1-NP; the HPLC profiles of the multiple adducts suggests that adducts may be formed via metabolic pathways that involve both nitroreduction and ring-oxidation. 6 references, 1 figure

Oxidative stress-mediated mouse liver lesions caused by Clonorchis sinensis infection.

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Maeng, Sejung; Lee, Hye Won; Bashir, Qudsia; Kim, Tae Im; Hong, Sung-Jong; Lee, Tae Jin; Sohn, Woon-Mok; Na, Byoung-Kuk; Kim, Tong-Soo; Pak, Jhang Ho

2016-03-01

Clonorchis sinensis is a high-risk pathogenic helminth that strongly provokes inflammation, epithelial hyperplasia, periductal fibrosis, and even cholangiocarcinoma in chronically infected individuals. Chronic inflammation is associated with an increased risk of various cancers due to the disruption of redox homeostasis. Accordingly, the present study was conducted to examine the time course relationship between histopathological changes and the appearance of oxidative stress markers, including lipid peroxidation, enzymes involved in lipid peroxidation, and mutagenic DNA adducts in the livers of mice infected with C. sinensis, as well as proinflammatory cytokines in infected mouse sera. Histopathological phenotypes such as bile duct epithelial hyperplasia, periductal fibrosis, edema and inflammatory infiltration increased in infected livers in a time-dependent manner. Intense immunoreactivity of lipid peroxidation products (4-hydroxy-2-nonenal; malondialdehyde), cyclooxygenase-2, 5-lipoxygenase and 8-oxo-7,8-dihydro-2'-deoxyguanosine were concomitantly observed in these injured regions. We also found elevated expressions of cyclooxygenase-2 and 5-lipoxygenase in C. sinensis excretory-secretory product-treated cholangiocarcinoma cells. Moreover, the levels of proinflammatory cytokines such as TNF-α, ILβ-1 and IL-6 were differentially upregulated in infected sera. With regard to oxidative stress-mediated carcinogenesis, our findings suggest that C. sinensis infestation may disrupt host redox homeostasis, creating a damaging environment that favors the development of advanced hepatobiliary diseases such as clonorchiasis-associated cholangiocarcinoma. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Isthmin 1 is a secreted protein expressed in skin, mucosal tissues, and NK, NKT, and th17 cells.

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Valle-Rios, Ricardo; Maravillas-Montero, José L; Burkhardt, Amanda M; Martinez, Cynthia; Buhren, Bettina Alexandra; Homey, Bernhard; Gerber, Peter Arne; Robinson, Octavio; Hevezi, Peter; Zlotnik, Albert

2014-10-01

Using a comprehensive microarray database of human gene expression, we identified that in mammals, a secreted protein known as isthmin 1 (ISM1) is expressed in skin, mucosal tissues, and selected lymphocyte populations. ISM1 was originally identified in Xenopus brain during development, and it encodes a predicted ∼50-kDa protein containing a signal peptide, a thrombospondin domain, and an adhesion-associated domain. We confirmed the pattern of expression of ISM1 in both human and mouse tissues. ISM1 is expressed by DX5(+) lung lymphocytes that include NK and NKT-like cells, and is also expressed by some CD4(+) T cells upon activation but its expression increases significantly when CD4(+) T cells were polarized to the Th17 lineage in vitro. The presence of IFN-γ during CD4(+) T cell polarization inhibits ISM1 expression. Given that ISM1 has been reported to have anti-angiogenic properties, these observations suggest that ISM1 is a mediator of lymphocyte effector functions and may participate in both innate and acquired immune responses.

Analyzing the temporal regulation of translation efficiency in mouse liver

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Peggy Janich

2016-06-01

Full Text Available Mammalian physiology and behavior follow daily rhythms that are orchestrated by endogenous timekeepers known as circadian clocks. Rhythms in transcription are considered the main mechanism to engender rhythmic gene expression, but important roles for posttranscriptional mechanisms have recently emerged as well (reviewed in Lim and Allada (2013 [1]. We have recently reported on the use of ribosome profiling (RPF-seq, a method based on the high-throughput sequencing of ribosome protected mRNA fragments, to explore the temporal regulation of translation efficiency (Janich et al., 2015 [2]. Through the comparison of around-the-clock RPF-seq and matching RNA-seq data we were able to identify 150 genes, involved in ribosome biogenesis, iron metabolism and other pathways, whose rhythmicity is generated entirely at the level of protein synthesis. The temporal transcriptome and translatome data sets from this study have been deposited in NCBI's Gene Expression Omnibus under the accession number GSE67305. Here we provide additional information on the experimental setup and on important optimization steps pertaining to the ribosome profiling technique in mouse liver and to data analysis.

Properties of the catalase molecule obtained from acatalasemic and hypocatalasemic mice Part I. Effects of denaturants on the catalase activity in the mouse liver

OpenAIRE

佐藤, 征紀

1985-01-01

Homogenates of mouse liver with isotonic sucrose solution were separated by the cell fractionation with repeating centrifugation. The supernatants were used for the inhibition test with the reagents such as 3,5 diiodosalicylic acid lithium salt (LIS), guanidine and azide, heat, acid and alkali. After various treatments, the remaining catalase activities were measured and showed as a relative enzyme activity. Stability of catalase in liver supernatants was compared normal (C3H/C(as)C(as)) and ...

Cinnamon extract improves insulin sensitivity in the brain and lowers liver fat in mouse models of obesity.

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Sartorius, Tina; Peter, Andreas; Schulz, Nadja; Drescher, Andrea; Bergheim, Ina; Machann, Jürgen; Schick, Fritz; Siegel-Axel, Dorothea; Schürmann, Annette; Weigert, Cora; Häring, Hans-Ulrich; Hennige, Anita M

2014-01-01

Treatment of diabetic subjects with cinnamon demonstrated an improvement in blood glucose concentrations and insulin sensitivity but the underlying mechanisms remained unclear. This work intends to elucidate the impact of cinnamon effects on the brain by using isolated astrocytes, and an obese and diabetic mouse model. Cinnamon components (eugenol, cinnamaldehyde) were added to astrocytes and liver cells to measure insulin signaling and glycogen synthesis. Ob/ob mice were supplemented with extract from cinnamomum zeylanicum for 6 weeks and cortical brain activity, locomotion and energy expenditure were evaluated. Insulin action was determined in brain and liver tissues. Treatment of primary astrocytes with eugenol promoted glycogen synthesis, whereas the effect of cinnamaldehyde was attenuated. In terms of brain function in vivo, cinnamon extract improved insulin sensitivity and brain activity in ob/ob mice, and the insulin-stimulated locomotor activity was improved. In addition, fasting blood glucose levels and glucose tolerance were greatly improved in ob/ob mice due to cinnamon extracts, while insulin secretion was unaltered. This corresponded with lower triglyceride and increased liver glycogen content and improved insulin action in liver tissues. In vitro, Fao cells exposed to cinnamon exhibited no change in insulin action. Together, cinnamon extract improved insulin action in the brain as well as brain activity and locomotion. This specific effect may represent an important central feature of cinnamon in improving insulin action in the brain, and mediates metabolic alterations in the periphery to decrease liver fat and improve glucose homeostasis.