Research
Abstract
Hepatitis B virus (HBV)-specific CD8+ T cells fail to acquire effector functions after priming in the liver, but the molecular basis for the dysfunctionality is poorly understood. By comparing the gene expression profile of intrahepatically primed, dysfunctional HBV-specific CD8+ T cells with that of systemically primed, functional effector counterparts, we found that the expression of interferon-stimulated genes (ISGs) is selectively suppressed in the dysfunctional CD8+ T cells. The ISG suppression was associated with impaired phosphorylation of STAT1 in response to IFNα treatment. Importantly, a strong induction of type interferons (IFN-Is) in the liver facilitated the functional differentiation of intrahepatically primed HBV-specific CD8+ T cells in association with the restoration of ISGs expression in the T cells. These results suggest that intrahepatic priming suppresses IFN-I signaling in CD8+ T cells, which may contribute to the dysfunctionality. The data also suggest a therapeutic value of the robust induction of intrahepatic IFN-Is for the treatment of chronic HBV infection.
Authors
Keigo Kawashima, Masanori Isogawa, Masaya Onishi, Ian Baudi, Satoru Saito, Atsushi Nakajima, Takashi Fujita, Yasuhito Tanaka
Abstract
The role of insulin receptor (IR) activated by hyperinsulinemia in obesity-induced kidney injury is not well understood. We hypothesized that activation of the kidney proximal tubule epithelial IR contributes to obesity-induced kidney injury. We administered normal fat diet (NFD) or high fat diet (HFD) to Control and kidney proximal tubule IR knock out (KPTIRKO) mice for 4 months. Renal cortical IR expression was decreased by 60% in male and female KPTIRKO mice. In KPTIRKO mice baseline serum glucose, serum creatinine, and urinary albumin to creatinine ratio (ACR) were similar to Controls. On HFD, weight gain and increase in serum cholesterol were similar in Control and KPTIRKO mice; blood glucose did not change. HFD increased the following parameters in the male Control mice: renal cortical contents of phosphorylated IR and Akt, matrix proteins, urinary ACR and kidney injury molecule-1 (KIM-1) to creatinine ratio, and systolic blood pressure. Renal cortical generation of hydrogen sulfide was reduced in HFD fed male Control mice. All of these parameters were ameliorated in male KPTIRKO mice. Interestingly, female mice were resistant to HFD-induced kidney injury in both genotypes. We conclude that HFD-induced kidney injury requires renal proximal tubule IR activation in male mice.
Authors
Hak Joo Lee, Meenalakshmi M. Mariappan, Luke Norton, Terry Bakewell, Denis Feliers, Sae Byeol Oh, Andrew Donati, Cherubina S. Rubannelsonkumar, Manjeri Venkatachalam, Stephen E. Harris, Isabelle Rubera, Michel Tauc, Goutam Ghosh Choudhury, C. Ronald Kahn, Kumar Sharma, Ralph A. DeFronzo, Balakuntalam S. Kasinath
Abstract
Ginger is known to have anti-inflammatory and anti-oxidative effects, and has traditionally been used as an herbal supplement in the treatment of various chronic diseases. Here, we report anti-neutrophil properties of 6-gingerol, the most abundant bioactive compound of ginger root, in models of lupus and antiphospholipid syndrome (APS). Specifically, we demonstrate that 6-gingerol attenuates neutrophil extracellular trap (NET) release in response to lupus- and APS-relevant stimuli through a mechanism that at least partially dependent on inhibition of phosphodiesterases. At the same time, administration of 6-gingerol to mice reduces NET release in various models of lupus and APS, while also improving other disease-relevant endpoints such as autoantibody formation and large-vein thrombosis. In summary, this study is the first to demonstrate a protective role for ginger-derived compounds in the context of lupus, and importantly provides a potential mechanism for these effects via phosphodiesterase inhibition and attenuation of neutrophil hyperactivity.
Authors
Ramadan A. Ali, Alex A. Gandhi, Lipeng Dai, Julia K. Weiner, Shanea K. Estes, Srilakshmi Yalavarthi, Kelsey Gockman, Duxin Sun, Jason S. Knight
Abstract
Impairment of GABAergic system has been reported in epilepsy, autism, ADHD and schizophrenia. We recently demonstrated that Ataxia Telangiectasia Mutated (ATM) shapes directly the development of GABAergic system. Here, we show for the first time how the abnormal expression of ATM impacts the pathological condition of autism. We exploit two different animal models of autism, the Mecp2y/- mouse model of Rett syndrome, and mice prenatally exposed to valproic acid, and found increased ATM levels. Accordingly, the treatment with the specific ATM kinase inhibitor KU55933 (KU) normalises molecular, functional and behavioural defects in these mouse models such as the i) delayed GABAergic development, ii) hippocampal hyper-excitability, iii) low cognitive performances, iv) social impairments. Mechanistically, we demonstrate that KU administration to wild type hippocampal neurons leads to i) higher Egr4 activity on Kcc2b promoter, ii) increased expression of Mecp2, iii) potentiated GABA-transmission. These results provide evidences and molecular substrates for the pharmacological development of ATM inhibition in autism spectrum disorders.
Authors
Lara Pizzamiglio, Elisa Focchi, Clara Maria Cambria, Luisa Ponzoni, Silvia Ferrara, Francesco Bifari, Genni Desiato, Nicoletta Landsberger, Luca Murru, Maria Passafaro, Mariaelvina Sala, MIchela Matteoli, Elisabetta Menna, Flavia Antonucci
Abstract
TrkB agonist drugs are shown here to have a significant effect on the regeneration of afferent cochlear synapses after noise-induced synaptopathy. The effects were consistent with regeneration of cochlear synapses that we observed in vitro after synaptic loss due to kainic acid-induced glutamate toxicity and were elicited by administration of TrkB agonists, amitriptyline and 7,8- dihydroxyflavone, directly into the cochlea via the posterior semicircular canal 48 h after exposure to noise. Synaptic counts at the inner hair cell and wave 1 amplitudes in the ABR were partially restored 2 weeks after drug treatment. Effects of amitriptyline on wave 1 amplitude and afferent auditory synapse numbers in noise-exposed ears after systemic (as opposed to local) delivery were profound and long-lasting; synapses in the treated animals remained intact one year after the treatment. However, the effect of systemically delivered amitriptyline on synaptic rescue was dependent on dose and the time window of administration: it was only effective when given before noise exposure at the highest injected dose. The long-lasting effect and the efficacy of post-exposure treatment indicate a potential broad application for the treatment of synaptopathy, which often goes undetected until well after the original damaging exposure(s).
Authors
Katharine A. Fernandez, Takahisa Watabe, Mingjie Tong, Xiankai Meng, Kohsuke Tani, Sharon G. Kujawa, Albert S.B. Edge
Abstract
Interleukin-10 (IL-10) is a critical cytokine used by immune cells to suppress inflammation. Paradoxically, immune cell-derived IL-10 can drive insulin resistance in obesity by suppressing adipocyte energy expenditure and thermogenesis. However, the source of IL-10 necessary for the suppression of adipocyte thermogenesis is unknown. We show here that CD4+ Foxp3+ regulatory T cells (Tregs) are a significant source of IL-10, and that Treg-derived IL-10 can suppress adipocyte beiging. Unexpectedly, Treg-specific loss of IL-10 resulted in increased insulin sensitivity and reduced obesity in high fat diet (HFD)-fed male mice. Mechanistically, we determined that Treg-specific loss of the transcription factor Blimp-1, a driver of IL-10 expression by Tregs, phenocopied the Treg-specific IL-10-deficient mice. Loss of Blimp-1 expression in Tregs resulted in reduced ST2+, KLRG1+, IL-10-secreting Tregs, particularly in the white adipose tissue. Blimp-1-deficient mice were protected from glucose intolerance, insulin resistance and diet-induced obesity (DIO), through increased white adipose tissue browning. Taken together, our data show that Blimp-1-regulated IL-10 secretion by Tregs represses white adipose tissue beiging to maintain adipose tissue homeostasis.
Authors
Lisa Y. Beppu, Raja Mooli, Xiaoyao Qu, Giovanni J. Marrero, Christopher A. Finley, Allen N. Fooks, Zackary P. Mullen, Adolfo B. Frias Jr., Ian J. Sipula, Bingxian Xie, Katherine E. Helfrich, Simon C. Watkins, Amanda C. Poholek, Sadeesh K. Ramakrishnan, Michael J. Jurczak, Louise M. D'Cruz
Abstract
Although many HIV cure strategies seek to expand HIV-specific CD8+ T cells to control the virus, all are likely to fail if cellular exhaustion is not prevented. A loss in stem-like memory properties (i.e., the ability to proliferate and generate secondary effector cells) is a key feature of exhaustion; little is known, however, about how these properties are regulated in human virus-specific CD8+ T cells. We found that virus-specific CD8+ T cells from humans and non-human primates naturally controlling HIV/SIV infection express more of the transcription factor, TCF-1, than non-controllers. HIV-specific CD8+ T cell TCF-1 expression correlated with memory marker expression and expansion capacity and declined with antigenic stimulation. CRISPR-Cas9 editing of TCF-1 in human primary T cells demonstrated a direct role in regulating expansion capacity. Collectively, these data suggest that TCF-1 contributes to the regulation of the stem-like memory property of secondary expansion capacity of HIV-specific CD8+ T cells, and they provide a rationale for exploring the enhancement of this pathway in T cell-based therapeutic strategies for HIV.
Authors
Rachel L. Rutishauser, Christian Deo T. Deguit, Joseph Hiatt, Franziska Blaeschke, Theodore L. Roth, Lynn Wang, Kyle A. Raymond, Carly E. Starke, Joseph C. Mudd, Wenxuan Chen, Carolyn P. Smullin, Rodrigo Matus-Nicodemos, Rebecca Hoh, Melissa R. Krone, Frederick M. Hecht, Christopher D. Pilcher, Jeffrey N. Martin, Richard A. Koup, Daniel C. Douek, Jason M. Brenchley, Rafick-Pierre Sékaly, Satish K. Pillai, Alexander Marson, Steven G. Deeks, Joseph M. McCune, Peter W. Hunt
Abstract
The cohesin complex plays an essential role in chromosome maintenance and transcriptional regulation. Recurrent somatic mutations in the cohesin complex are frequent genetic drivers in cancer including myelodysplatic syndromes (MDS) and acute myeloid leukemia (AML). Here, using genetic dependency screens of STAG2-mutant AML, we identified DNA damage repair and replication as genetic dependencies in cohesin-mutant cells. We demonstrated increased levels of DNA damage and sensitivity of cohesin-mutant cells to PARP inhibition. We developed a mouse model of MDS in which Stag2 mutations arise as clonal secondary lesions in the background of clonal hematopoiesis driven by Tet2 mutations, and demonstrated selective depletion of cohesin-mutant cells with PARP inhibition in vivo. Finally, we demonstrated a shift from STAG2- to STAG1-containing cohesin complexes in cohesin-mutant cells, which is associated with longer DNA loop extrusion, more intermixing of chromatin compartments, and increased interaction with PARP and RPA proteins. Our findings inform the biology and therapeutic opportunities for cohesin-mutant malignancies.
Authors
Zuzana Tothova, Anne-Laure Valton, Rebecca Gorelov, Mounica Vallurupalli, John M. Krill-Burger, Amie Holmes, Catherine C. Landers, J. Erika Haydu, Edyta Malolepsza, Christina R. Hartigan, Melanie Donahue, Katerina D. Popova, Sebastian H. J. Koochaki, Sergey V. Venev, Jeanne F. Rivera, Edwin Chen, Kasper Lage, Monica Schenone, Alan D. D'Andrea, Steven A. Carr, Elizabeth A. Morgan, Job Dekker, Benjamin L. Ebert
Abstract
Clinical trials of biologic therapies in type 1 diabetes (T1D) aim to mitigate autoimmune destruction of pancreatic beta cells through immune perturbation and serve as resources to elucidate immunological mechanisms in health and disease. In the T1DAL trial of alefacept (LFA3-Ig) in recent onset T1D, endogenous insulin production was preserved in 30% of subjects for two years post-therapy. Given our previous findings linking exhausted CD8 T cells to beneficial response in T1D trials, we applied unbiased analyses to sorted CD8 T cells to evaluate their potential role in T1DAL. Using RNA-seq, we found that greater insulin C-peptide preservation was associated with a module of activation- and exhaustion-associated genes. This signature was dissected into two distinct CD8 memory populations through correlation with clustered cytometry data. Both populations were hypo-proliferative, shared expanded TCR junctions, and expressed exhaustion-associated markers including TIGIT and KLRG1. The populations were distinguished by reciprocal expression of CD8 T and NK cell markers (GZMB, CD57 and inhibitory KIR genes), versus T cell activation and differentiation markers (PD1 and CD28). These findings support previous evidence linking exhausted CD8 T cells to successful immune interventions for T1D, while suggesting multiple inhibitory mechanisms can promote this beneficial cell state.
Authors
Kirsten E. Diggins, Elisavet Serti, Virginia S. Muir, Mario G. Rosasco, TingTing Lu, Elisa Balmas, Gerald T. Nepom, S. Alice Long, Peter S. Linsley
Abstract
Computational models based on recent maps of the red blood cell proteome suggest that mature erythrocytes may harbor targets for common drugs. This prediction is relevant to red blood cell storage in the blood bank, in which the impact of small molecule drugs or other xenometabolites deriving from dietary, iatrogenic or environmental exposures (“exposome”) may alter erythrocyte energy and redox metabolism and, in so doing, affect red cell storage quality and post-transfusion efficacy. To test this prediction, here we provide a comprehensive characterization of the blood donor exposome, including the detection of common prescription and over-the-counter drugs in 250 units donated by healthy volunteers from the REDS-III RBC Omics study. Based on high-throughput drug screenings of 1,366 FDA-approved drugs, we report a significant impact of ~65% of the tested drugs on erythrocyte metabolism. Machine learning models built using metabolites as predictors were able to accurately predict drugs for several drug classes/targets (bisphosphonates, anticholinergics, calcium channel blockers, adrenergics, proton-pump inhibitors, antimetabolites, selective serotonin reuptake inhibitors, and mTOR) suggesting that these drugs have a direct, conserved, and significant impact on erythrocyte metabolism. As a proof of principle, here we show that the antiacid ranitidine – though rarely detected in the blood donor population – has a strong effect on RBC markers of storage quality in vitro. We thus show that ranitidine supplementation to blood units could improve erythrocyte metabolism and storage quality when supplemented to blood bags, through mechanisms involving sphingosine 1-phosphate-dependent modulation of erythrocyte glycolysis and/or direct binding to hemoglobin.
Authors
Travis Nemkov, Davide Stefanoni, Aarash Bordbar, Aaron Issaian, Bernhard O. Palsson, Larry J. Dumont, Ariel M. Hay, Anren Song, Yang Xia, Jasmina S. Redzic, Elan Z. Eisenmesser, James C. Zimring, Steve Kleinman, Kirk C. Hansen, Michael Busch, Angelo D’Alessandro
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