Natural killer (NK) cell suppression of T cells is a key determinant of viral pathogenesis and vaccine efficacy. This process involves perforin-dependent elimination of activated CD4 T cells during the first three days of infection. Although this mechanism requires cell-cell contact, NK cells and T cells typically reside in different compartments of lymphoid tissues at steady state. Here, we showed that NK-cell suppression of T cells is associated with transient accumulation of NK cells within T cell-rich sites of the spleen during lymphocytic choriomeningitis virus infection. The chemokine receptor CXCR3 was required for this relocation and suppression of antiviral T cells. Accordingly, NK-cell migration was mediated by type I interferon (IFN)-dependent promotion of CXCR3 ligand expression. In contrast, adenoviral vectors that weakly induced type I IFN and did not stimulate NK-cell inhibition of T cells also did not promote measurable redistribution of NK cells to T-cell zones. Exogenous IFN rescued NK-cell migration during adenoviral vector immunization. Thus, type I IFN and CXCR3 were critical for properly positioning NK cells to constrain antiviral T-cell responses. Development of strategies to curtail migration of NK cells between lymphoid compartments may enhance vaccine-elicited immune responses.
Ayad Ali, Laura M. Canaday, H. Alex Feldman, Hilal Cevik, Michael T. Moran, Sanjeeth Rajaram, Nora Lakes, Jasmine A. Tuazon, Harsha Seelamneni, Durga Krishnamurthy, Eryn Blass, Dan H. Barouch, Stephen N. Waggoner
The start codon c.1A>G mutation in KLHL24, encoding ubiquitin-ligase KLHL24, results in the loss of 28 N-terminal amino acids (KLHL24-ΔN28) by skipping the initial start codon. In skin, KLHL24-ΔN28 leads to gain of function, excessively targeting intermediate filament keratin-14 for proteasomal degradation, ultimately causing epidermolysis bullosa simplex (EBS). The majority of these EBS-patients are also diagnosed with dilated cardiomyopathy (DCM), but the pathological mechanism in the heart is unknown. As desmin is the cardiac homologue of keratin-14, we hypothesized that KLHL24-ΔN28 leads to excessive degradation of desmin, resulting in DCM. Dynamically loaded engineered heart tissues (dyn-EHTs) were generated from human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes from two patients and three (non)familial controls. Ten-fold lower desmin protein levels were observed in patient-derived dyn-EHTs, in line with diminished desmin levels detected in patients’ explanted heart. This was accompanied by tissue dilatation, impaired mitochondrial function, decreased force values and increased cardiomyocyte stress. HEK293 transfection studies confirmed KLHL24-mediated desmin degradation. KLHL24 RNA interference or direct desmin overexpression recovered desmin protein levels, restoring morphology and function in patient-derived dyn-EHTs. To conclude, presence of KLHL24-ΔN28 in cardiomyocytes leads to excessive degradation of desmin, affecting tissue morphology and function, that can be prevented by restoring desmin protein levels.
Mathilde C.S.C. Vermeer, Maria C. Bolling, Jacqueline M. Bliley, Karla F. Arevalo Gomez, Mario G. Pavez-Giani, Duco Kramer, Pedro H. Romero-Herrera, B. Daan Westenbrink, Gilles F.H. Diercks, Maarten P. van den Berg, Adam W. Feinberg, Herman H. W. Silljé, Peter van der Meer
Alcohol use disorder (AUD) is associated with substantial morbidity, mortality, and societal cost, and pharmacological treatment options for AUD are limited. The endogenous cannabinoid (eCB) signaling system is critically involved in reward processing and alcohol intake is positively correlated with release of the eCB ligand 2-Arachidonoylglycerol (2-AG) within reward neurocircuitry. Here we show that genetic and pharmacological inhibition of diacylglycerol lipase (DAGL), the rate limiting enzyme in the synthesis of 2-AG, reduces alcohol consumption in a variety of preclinical models ranging from a voluntary free-access model to aversion resistant-drinking and dependence-like drinking induced via chronic intermittent ethanol vapor exposure in mice. DAGL inhibition during either chronic alcohol consumption or protracted withdrawal was devoid of anxiogenic and depressive-like behavioral effects. Lastly, DAGL inhibition also prevented ethanol-induced suppression of GABAergic transmission onto midbrain dopamine neurons, providing mechanistic insight into how DAGL inhibition could affect alcohol reward. These data suggest reducing 2-AG signaling via inhibition of DAGL could represent an effective approach to reduce alcohol consumption across the spectrum of AUD severity.
Nathan D. Winters, Gaurav Bedse, Anastasia A. Astafyev, Toni A. Patrick, Megan Altemus, Amanda J. Morgan, Snigdha Mukerjee, Keenan D. Johnson, Vikrant R. Mahajan, Md. Jashim Uddin, Philip J. Kingsley, Samuel W. Centanni, Cody A. Siciliano, David C. Samuels, Lawrence J. Marnett, Danny G. Winder, Sachin Patel
Intratumoral T cells that might otherwise control tumors are often identified in an ‘exhausted’ state, defined by specific epigenetic modifications and upregulation of genes such as CD38, CTLA-4 and PD-1. While the term might imply inactivity, there has been little study of this state at the phenotypic level in tumors to understand the extent of their incapacitation. Starting with the observation that T cells move more quickly through mouse tumors as residence time increases and they progress towards exhaustion, we elaborated a non-stimulatory live-biopsy method for real-time study of T cell behaviors within individual patient tumors. Using two-photon microscopy, we studied native CD8 T cells interacting with APCs and cancer cells in different micro-niches of human tumors, finding that T cell speed was variable by region and by patient and was inversely correlated with local tumor density. Across a range of tumor types, we found a strong relationship between CD8 T cell motility and exhausted T cell state that corresponds to observations made in mouse models where exhausted T cells move faster. Our study demonstrates T cell dynamic states in individual human tumors and supports the existence of an active program in ‘exhausted’ T cells that extends beyond incapacitating them.
Ran You, Jordan Artichoker, Adam Fries, Austin W. Edwards, Alexis J. Combes, Gabriella C. Reeder, Bushra Samad, Matthew F. Krummel
Skeletal muscle can undergo a regenerative process from injury or disease to preserve muscle mass and function, which is critically influenced by cellular stress responses. Inositol-requiring enzyme 1 (IRE1) is an ancient endoplasmic reticulum (ER) stress sensor and mediates a key branch of the unfolded protein response (UPR). In mammals, IRE1α is implicated in the homeostatic control of stress responses during tissue injury and regeneration. Here, we show that IRE1α serves as a myogenic regulator in skeletal muscle regeneration in response to injury and muscular dystrophy. We found in mice that IRE1α was activated during injury-induced muscle regeneration, and muscle-specific IRE1α ablation resulted in impaired regeneration upon cardiotoxin-induced injury. Gain- and loss-of-function studies in myocytes demonstrated that IRE1αacts to sustain both differentiation in myoblasts and hypertrophy in myotubes through regulated IRE1-dependent decay (RIDD) of mRNA encoding Myostatin, a key negative regulator of muscle repair and growth. Furthermore, in the mouse model of Duchenne muscular dystrophy (DMD), loss of muscle IRE1α resulted in augmented Myostatin signaling and exacerbated the dystrophic phenotypes. Thus, these results reveal a pivotal role for the RIDD output of IRE1α in muscle regeneration, offering new insight into potential therapeutic strategies for muscle loss diseases.
Shengqi He, Tingting Fu, Yue Yu, Qinhao Liang, Luyao Li, Jing Liu, Xuan Zhang, Qian Zhou, Qiqi Guo, Dengqiu Xu, Yong Chen, Xiaolong Wang, Yulin Chen, Jianmiao Liu, Zhenji Gan, Yong Liu
Both epidemiologic and cellular studies in the context of autoimmune diseases have established that protein tyrosine phosphatase non-receptor type 22 (PTPN22) is a key regulator of T cell receptor (TCR) signaling. However, its mechanism of action in tumors and its translatability as a target for cancer immunotherapy have not been established. Here we show that a germline variant of PTPN22, rs2476601, portended a lower likelihood of cancer in patients. PTPN22 expression was also associated with markers of immune regulation in multiple cancer types. In mice, lack of PTPN22 augmented antitumor activity with greater infiltration and activation of macrophages, natural killer (NK) cells, and T cells. Notably, we generated a novel small molecule inhibitor of PTPN22, named L-1, that phenocopied the antitumor effects seen in genotypic PTPN22 knockout. PTPN22 inhibition promoted activation of CD8+ T cells and macrophage subpopulations toward MHC-II expressing M1-like phenotypes, both of which were necessary for successful antitumor efficacy. Increased PD1-PDL1 axis in the setting of PTPN22 inhibition could be further leveraged with PD1 inhibition to augment antitumor effects. Similarly, cancer patients with the rs2476601 variant responded significantly better to checkpoint inhibitor immunotherapy. Our findings suggest that PTPN22 is a druggable systemic target for cancer immunotherapy.
Won Jin Ho, Sarah Croessmann, Jianping Lin, Zaw H. Phyo, Soren Charmsaz, Ludmila Danilova, Aditya A. Mohan, Nicole E. Gross, Fangluo Chen, Jiajun Dong, Devesh Aggarwal, Yunpeng Bai, Janey Wang, Jing He, James M. Leatherman, Mark Yarchoan, Todd D. Armstrong, Neeha Zaidi, Elana J. Fertig, Joshua C. Denny, Ben H. Park, Zhong-Yin Zhang, Elizabeth M. Jaffee
BACKGROUND. Certain components of rest-activity rhythms such as greater eveningness (delayed phase), physical inactivity (blunted amplitude) and shift work (irregularity) are associated with increased risk for drug use. Dopaminergic (DA) signaling has been hypothesized to mediate the associations, though clinical evidence is lacking. METHODS. We examined associations between rhythm components and striatal D1 (D1R) and D2/3 receptor (D2/3R) availability in 32 healthy adults (12 female, age: 42.40±12.22) and its relationship to drug reward. Rest-activity rhythms were assessed by one-week actigraphy combined with self-reports. [11C]NNC112 and [11C]raclopride Positron Emission Tomography (PET) scans were conducted to measure D1R and D2/3R availability, respectively. Additionally, self-reported drug-rewarding effects of 60 mg oral methylphenidate were assessed. RESULTS. We found that delayed rhythm was associated with higher D1R availability in caudate, which was not attributable to sleep loss or ‘social jet lag’, whereas physical inactivity was associated with higher D2/3R availability in nucleus accumbens (NAc). Delayed rest-activity rhythm, higher caudate D1R and NAc D2/3R availability were associated with greater sensitivity to the rewarding effects of methylphenidate. CONCLUSION. These findings reveal specific components of rest-activity rhythms associated with striatal D1R, D2/3R availability and drug-rewarding effects. Personalized interventions that target rest-activity rhythms may help prevent and treat substance use disorders. TRIAL REGISTRATION. ClinicalTrials.gov: NCT03190954 FUNDING. This work was accomplished with support from the National Institute on Alcohol Abuse and Alcoholism (ZIAAA000550).
Rui Zhang, Peter Manza, Dardo Tomasi, Sung Won Kim, Ehsan Shokri-Kojori, Sukru B. Demiral, Danielle S. Kroll, Dana E. Feldman, Katherine L. McPherson, Catherine L. Biesecker, Gene-Jack Wang, Nora D. Volkow
Hepatic uptake and biosynthesis of fatty acids (FA), as well as the partitioning of FA into oxidative, storage, and secretory pathways are tightly regulated processes. Dysregulation of one or more of these processes can promote excess hepatic lipid accumulation, ultimately leading to systemic metabolic dysfunction. Angiopoietin-like-4 (ANGPTL4) is a secretory protein that inhibits lipoprotein lipase (LPL) and modulates triacylglycerol (TAG) homeostasis. To understand the role of ANGPTL4 in liver lipid metabolism under normal and high-fat fed conditions, we generated hepatocyte specific Angptl4 mutant mice (Hmut). Using metabolic turnover studies, we demonstrate that hepatic Angptl4 deficiency facilitates catabolism of TAG-rich lipoprotein (TRL) remnants in the liver via increased hepatic lipase (HL) activity, which results in a significant reduction in circulating TAG and cholesterol levels. Consequently, depletion of hepatocyte Angptl4 protects against diet-induce obesity, glucose intolerance, liver steatosis, and atherogenesis. Mechanistically, we demonstrate that loss of Angptl4 in hepatocytes promotes FA uptake which results in increased FA oxidation, ROS production, and AMPK activation. Finally, we demonstrate the utility of a targeted pharmacologic therapy that specifically inhibits Angptl4 gene expression in the liver and protects against diet-induced obesity, dyslipidemia, glucose intolerance, and liver damage, which likely occurs via increased HL activity. Notably, this novel inhibition strategy does not cause any of the deleterious effects previously observed with neutralizing antibodies.
Abhishek K. Singh, Balkrishna Chaube, Xinbo Zhang, Jonathan Sun, Kathryn M. Citrin, Alberto Canfrán-Duque, Binod Aryal, Noemi Rotllan, Luis Varela, Richard G. Lee, Tamas L. Horvath, Nathan Price, Yajaira Suárez, Carlos Fernandez-Hernando
In view of emerging drug-resistant tuberculosis (TB), host directed adjunct therapies are urgently needed to improve treatment outcomes with currently available anti-TB therapies. One approach is to interfere with the formation of lipid-laden "foamy" macrophages in the host, as they provide a nutrient-rich host cell environment for Mycobacterium tuberculosis (Mtb). Here, we provide evidence that Wnt family member 6 (WNT6), a ligand of the evolutionarily conserved Wingless/Integrase 1 (WNT) signaling pathway, promotes foam cell formation by regulating key lipid metabolic genes including acetyl-CoA carboxylase-2 (ACC2) during pulmonary TB. Using genetic and pharmacological approaches, we demonstrated that lack of functional WNT6 or ACC2 significantly reduced intracellular triacylglycerol (TAG) levels and Mtb survival in macrophages. Moreover, treatment of Mtb-infected mice with a combination of a pharmacological ACC2 inhibitor and the anti-TB drug isoniazid (INH) reduced lung TAG and cytokine levels, as well as lung weights compared to treatment with INH alone. This combination also reduced Mtb bacterial numbers and the size of mononuclear cell infiltrates in livers of infected mice. In summary, our findings demonstrated that Mtb exploits WNT6/ACC2-induced storage of TAGs in macrophages to facilitate its intracellular survival, a finding opening new perspectives for host directed adjunctive treatment of pulmonary TB.
Julius Brandenburg, Sebastian Marwitz, Simone C. Tazoll, Franziska Waldow, Barbara Kalsdorf, Tim Vierbuchen, Thomas Scholzen, Annette Gross, Svenja Goldenbaum, Alexandra Hölscher, Martina Hein, Lara Linnemann, Maja Reimann, Andreas Kispert, Michael Leitges, Jan Rupp, Christoph Lange, Stefan Niemann, Jochen Behrends, Torsten Goldmann, Holger Heine, Ulrich E. Schaible, Christoph Hölscher, Dominik Schwudke, Norbert Reiling
PFKP (phosphofructokinase, platelet), the major isoform of PFK1 expressed in T cell acute lymphoblastic leukemia (T-ALL), is predominantly expressed in the cytoplasm to carry out its glycolytic function. Our study showed PFKP was a cyto-nuclear shuttling protein with functional nuclear export and nuclear localization sequences. Cyclin D3/CDK6 facilitated PFKP nuclear translocation by dimerization and by exposing the NLS of PFKP to induce the interaction between PFKP and importin 9. Nuclear PFKP stimulated the expression of C-X-C chemokine receptor type 4 (CXCR4), a chemokine receptor regulating leukemia homing/infiltration, to promote T-ALL cell invasion, which depended on the activity of c-Myc. In vivo experiments showed that nuclear PFKP promoted leukemia homing/infiltration into the bone marrow, spleen and liver, which could be blocked with CXCR4 antagonists. Immunohistochemistry staining of tissues from a clinically well-annotated cohort of T cell lymphoma/leukemia patients showed nuclear PFKP localization only in invasive cancers, but not in non-malignant T lymph node or reactive hyperplasia. The presence of nuclear PFKP in these specimens correlated with poor survival in patients with T cell malignancy, suggesting the potential utility of nuclear PFKP as a diagnostic marker.
Xueliang Gao, Shenghui Qin, Yongxia Wu, Chen Chu, Baishan Jiang, Roger H. Johnson, Dong Kuang, Jie Zhang, Xi Wang, Anand Mehta, Kenneth D. Tew, Gustavo W. Leone, Xue-Zhong Yu, Haizhen Wang
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