Natural killer (NK) cells can be divided into phenotypic subsets based on expression of receptors that bind self-MHC-I molecules, a concept termed licensing or education. Here we show NK cell subsets with different migratory, effector, and immunoregulatory functions in dendritic cell and antigen (ag)-specific CD8+ T cell responses during influenza and murine cytomegalovirus infections. Shortly after infection, unlicensed NK cells localized in draining lymph nodes and produced GM-CSF, which correlated with the expansion and activation of dendritic cells, and resulted in greater and sustained ag-specific T cell responses. In contrast, licensed NK cells preferentially migrated to infected tissues and produced IFN-γ. Importantly, human NK cell subsets exhibited similar phenotypic characteristics. Collectively, our studies demonstrate a critical demarcation between the functions of licensed and unlicensed NK cell subsets, with the former functioning as the classical effector subset and the latter as the stimulator of adaptive immunity helping to prime immune responses.
Anthony E. Zamora, Ethan G. Aguilar, Can M. Sungur, Lam T. Khuat, Cordelia Dunai, G. Raymond Lochhead, Juan Du, Claire Pomeroy, Bruce R. Blazar, Dan L. Longo, Jeffrey M. Venstrom, Nicole Baumgarth, William J. Murphy
Many extremely preterm infants (born before 28 gestational weeks [GWs]) develop cognitive impairment in later life, although the underlying pathogenesis is not yet completely understood. Our examinations of the developing human neocortex confirmed that neuronal migration continues beyond 23 GWs, the gestational week at which extremely preterm infants have live births. We observed larger numbers of ectopic neurons in the white matter of the neocortex in human extremely preterm infants with brain injury and hypothesized that altered neuronal migration may be associated with cognitive impairment in later life. To confirm whether preterm brain injury affects neuronal migration, we produced brain damage in mouse embryos by occluding the maternal uterine arteries. The mice showed delayed neuronal migration, ectopic neurons in the white matter, altered neuronal alignment, and abnormal corticocortical axonal wiring. Similar to human extremely preterm infants with brain injury, the surviving mice exhibited cognitive deficits. Activation of the affected medial prefrontal cortices of the surviving mice improved working memory deficits, indicating that decreased neuronal activity caused the cognitive deficits. These findings suggest that altered neuronal migration altered by brain injury might contribute to the subsequent development of cognitive impairment in extremely preterm infants.
Ken-ichiro Kubo, Kimiko Deguchi, Taku Nagai, Yukiko Ito, Keitaro Yoshida, Toshihiro Endo, Seico Benner, Wei Shan, Ayako Kitazawa, Michihiko Aramaki, Kazuhiro Ishii, Minkyung Shin, Yuki Matsunaga, Kanehiro Hayashi, Masaki Kakeyama, Chiharu Tohyama, Kenji F. Tanaka, Kohichi Tanaka, Sachio Takashima, Masahiro Nakayama, Masayuki Itoh, Yukio Hirata, Barbara Antalffy, Dawna D. Armstrong, Kiyofumi Yamada, Ken Inoue, Kazunori Nakajima
Cholesterol accumulation in the liver is an early event in nonalcoholic fatty liver disease (NAFLD). Here, we demonstrate that E2F1 plays a crucial role in maintaining cellular cholesterol homeostasis by regulating cholesterol uptake via proprotein convertase subtilisin/kexin 9 (PCSK9), an enzyme that promotes low-density lipoprotein receptor (LDLR) degradation upon activation.
Qiuwen Lai, Albert Giralt, Cédric Le May, Lianjun Zhang, Bertrand Cariou, Pierre-Damien Denechaud, Lluis Fajas
Metabolic dysregulation promotes cancer growth through not only energy production, but also epigenetic reprogramming. Here, we report that a critical node in methyl donor metabolism, nicotinamide N-methyltransferase (NNMT), ranked among the most consistently overexpressed metabolism genes in glioblastoma relative to normal brain. NNMT was preferentially expressed by mesenchymal glioblastoma stem cells (GSCs). NNMT depletes S-adenosyl methionine (SAM), a methyl donor generated from methionine. GSCs contained lower levels of methionine, SAM, and nicotinamide, but they contained higher levels of oxidized nicotinamide adenine dinucleotide (NAD+) than differentiated tumor cells. In concordance with the poor prognosis associated with DNA hypomethylation in glioblastoma, depletion of methionine, a key upstream methyl group donor, shifted tumors toward a mesenchymal phenotype and accelerated tumor growth. Targeting NNMT expression reduced cellular proliferation, self-renewal, and in vivo tumor growth of mesenchymal GSCs. Supporting a mechanistic link between NNMT and DNA methylation, targeting NNMT reduced methyl donor availability, methionine levels, and unmethylated cytosine, with increased levels of DNA methyltransferases, DNMT1 and DNMT3A. Supporting the clinical significance of these findings, NNMT portended poor prognosis for glioblastoma patients. Collectively, our findings support NNMT as a GSC-specific therapeutic target in glioblastoma by disrupting oncogenic DNA hypomethylation.
Jinkyu Jung, Leo J.Y. Kim, Xiuxing Wang, Qiulian Wu, Tanwarat Sanvoranart, Christopher G. Hubert, Briana C. Prager, Lisa C. Wallace, Xun Jin, Stephen C. Mack, Jeremy N. Rich
DCs are necessary and sufficient for induction of allergic airway inflammation. CD11b+ DCs direct the underlying Th2 immunity, but debate surrounds the function of CD103+ DCs in lung immunity and asthma after an allergic challenge. We challenged
Laura Conejero, Sofía C. Khouili, Sarai Martínez-Cano, Helena M. Izquierdo, Paola Brandi, David Sancho
Severe asthma (SA) is a significant problem both clinically and economically, given its poor response to corticosteroids (CS). We recently reported a complex type 1–dominated (IFN-γ–dominated) immune response in more than 50% of severe asthmatics despite high-dose CS treatment. Also, IFN-γ was found to be critical for increased airway hyperreactivity (AHR) in our model of SA. The transcription factor IRF5 expressed in M1 macrophages can induce a Th1/Th17 response in cocultured human T cells. Here we show markedly higher expression of IRF5 in bronchoalveolar lavage (BAL) cells of severe asthmatics as compared with that in cells from milder asthmatics or healthy controls. Using our SA mouse model, we demonstrate that lack of IRF5 in lymph node migratory DCs severely limits their ability to stimulate the generation of IFN-γ– and IL-17–producing CD4+ T cells and
Timothy B. Oriss, Mahesh Raundhal, Christina Morse, Rachael E. Huff, Sudipta Das, Rachel Hannum, Marc C. Gauthier, Kathryn L. Scholl, Krishnendu Chakraborty, Seyed M. Nouraie, Sally E. Wenzel, Prabir Ray, Anuradha Ray
Allogeneic hematopoietic cell transplantation (allo-HCT) is an effective immunotherapy for a variety of hematologic malignances, yet its efficacy is impeded by the development of graft-versus-host disease (GVHD). GVHD is characterized by activation, expansion, cytokine production, and migration of alloreactive donor T cells. Hence, strategies to limit GVHD are highly desirable. Ceramides are known to contribute to inflammation and autoimmunity. However, their involvement in T-cell responses to alloantigens is undefined. In the current study, we specifically characterized the role of ceramide synthase 6 (CerS6) after allo-HCT using genetic and pharmacologic approaches. We found that CerS6 was required for optimal T cell activation, proliferation, and cytokine production in response to alloantigen and for subsequent induction of GVHD. However, CerS6 was partially dispensable for the T cell–mediated antileukemia effect. At the molecular level, CerS6 was required for efficient TCR signal transduction, including tyrosine phosphorylation, ZAP-70 activation, and PKCθ/TCR colocalization. Impaired generation of C16-ceramide was responsible for diminished allogeneic T cell responses. Furthermore, targeting CerS6 using a specific inhibitor significantly reduced T cell activation in mouse and human T cells in vitro. Our study provides a rationale for targeting CerS6 to control GVHD, which would enhance the efficacy of allo-HCT as an immunotherapy for hematologic malignancies in the clinic.
M. Hanief Sofi, Jessica Heinrichs, Mohammed Dany, Hung Nguyen, Min Dai, David Bastian, Steven Schutt, Yongxia Wu, Anusara Daenthanasanmak, Salih Gencer, Aleksandra Zivkovic, Zdzislaw Szulc, Holger Stark, Chen Liu, Ying-Jun Chang, Besim Ogretmen, Xue-Zhong Yu
Infusion of in vitro–derived T cell progenitor (proT) therapy with hematopoietic stem cell transplant aids the recovery of the thymus damaged by total body irradiation. To understand the interaction between proTs and the thymic microenvironment, WT mice were lethally irradiated and given T cell–deficient (
Michelle J. Smith, Dawn K. Reichenbach, Sarah L. Parker, Megan J. Riddle, Jason Mitchell, Kevin C. Osum, Mahmood Mohtashami, Heather E. Stefanski, Brian T. Fife, Avinash Bhandoola, Kristin A. Hogquist, Georg A. Holländer, Juan Carlos Zúñiga-Pflücker, Jakub Tolar, Bruce R. Blazar
Many effector mechanisms of neutrophils have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Neutrophil extracellular traps (NETs) have been assigned a particularly detrimental role. Here we investigated the functional impact of neutrophils and NETs on a mouse model of lupus triggered by intraperitoneal injection of the cell death–inducing alkane pristane. Pristane-induced lupus (PIL) was aggravated in 2 mouse strains with impaired induction of NET formation, i.e., NOX2-deficient (
Deborah Kienhöfer, Jonas Hahn, Julia Stoof, Janka Zsófia Csepregi, Christiane Reinwald, Vilma Urbonaviciute, Caroline Johnsson, Christian Maueröder, Malgorzata J. Podolska, Mona H. Biermann, Moritz Leppkes, Thomas Harrer, Malin Hultqvist, Peter Olofsson, Luis E. Munoz, Attila Mocsai, Martin Herrmann, Georg Schett, Rikard Holmdahl, Markus H. Hoffmann
Though recent reports suggest that neutrophil extracellular traps (NETs) are a source of antigenic nucleic acids in systemic lupus erythematosus (SLE), we recently showed that inhibition of NETs by targeting the NADPH oxidase complex via cytochrome b-245, β polypeptide (
Rachael A. Gordon, Jan M. Herter, Florencia Rosetti, Allison M. Campbell, Hiroshi Nishi, Michael Kashgarian, Sheldon I. Bastacky, Anthony Marinov, Kevin M. Nickerson, Tanya N. Mayadas, Mark J. Shlomchik
Advanced cancer induces fundamental changes in metabolism and promotes cardiac atrophy and heart failure. We discovered systemic insulin deficiency in cachectic cancer patients. Similarly, mice with advanced B16F10 melanoma (B16F10-TM) or colon 26 carcinoma (C26-TM) displayed decreased systemic insulin associated with marked cardiac atrophy, metabolic impairment, and function. B16F10 and C26 tumors decrease systemic insulin via high glucose consumption, lowering pancreatic insulin production and producing insulin-degrading enzyme. As tumor cells consume glucose in an insulin-independent manner, they shift glucose away from cardiomyocytes. Since cardiomyocytes in both tumor models remained insulin responsive, low-dose insulin supplementation by subcutaneous implantation of insulin-releasing pellets improved cardiac glucose uptake, atrophy, and function, with no adverse side effects. In addition, by redirecting glucose to the heart in addition to other organs, the systemic insulin treatment lowered glucose usage by the tumor and thereby decreased tumor growth and volume. Insulin corrected the cancer-induced reduction in cardiac Akt activation and the subsequent overactivation of the proteasome and autophagy. Thus, cancer-induced systemic insulin depletion contributes to cardiac wasting and failure and may promote tumor growth. Low-dose insulin supplementation attenuates these processes and may be supportive in cardio-oncologic treatment concepts.
James T. Thackeray, Stefan Pietzsch, Britta Stapel, Melanie Ricke-Hoch, Chun-Wei Lee, Jens P. Bankstahl, Michaela Scherr, Jörg Heineke, Gesine Scharf, Arash Haghikia, Frank M. Bengel, Denise Hilfiker-Kleiner
Izumi Ohigashi, Yuki Ohte, Kazuya Setoh, Hiroshi Nakase, Akiko Maekawa, Hiroshi Kiyonari, Yoko Hamazaki, Miho Sekai, Tetsuo Sudo, Yasuharu Tabara, Hiromi Sawai, Yosuke Omae, Rika Yuliwulandari, Yasuhito Tanaka, Masashi Mizokami, Hiroshi Inoue, Masanori Kasahara, Nagahiro Minato, Katsushi Tokunaga, Keiji Tanaka, Fumihiko Matsuda, Shigeo Murata, Yousuke Takahama