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Abstract

No known therapies can prevent anaphylaxis. Bruton’s tyrosine kinase (BTK) is an enzyme thought to be essential for high-affinity IgE receptor (FcεRI) signaling in human cells. We tested the hypothesis that FDA-approved BTK inhibitors (BTKis) would prevent IgE-mediated responses including anaphylaxis. We showed that irreversible BTKis broadly prevented IgE-mediated degranulation and cytokine production in primary human mast cells and blocked allergen-induced contraction of isolated human bronchi. To address their efficacy in vivo, we created and used what we believe to be a novel humanized mouse model of anaphylaxis that does not require marrow ablation or human tissue implantation. After a single intravenous injection of human CD34+ cells, NSG-SGM3 mice supported the population of mature human tissue-resident mast cells and basophils. These mice showed excellent responses during passive systemic anaphylaxis using human IgE to selectively evoke human mast cell and basophil activation, and response severity was controllable by alteration of the amount of allergen used for challenge. Remarkably, pretreatment with just 2 oral doses of the BTKi acalabrutinib completely prevented moderate IgE-mediated anaphylaxis in these mice and also significantly protected against death during severe anaphylaxis. Our data suggest that BTKis may be able to prevent anaphylaxis in humans by inhibiting FcεRI-mediated signaling.

Authors

Melanie C. Dispenza, Rebecca A. Krier-Burris, Krishan D. Chhiba, Bradley J. Undem, Piper A. Robida, Bruce S. Bochner

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Abstract

BACKGROUND From March 2, 2020, to April 12, 2020, New York City (NYC) experienced exponential growth of the COVID-19 pandemic due to novel coronavirus (SARS-CoV-2). Little is known regarding how physicians have been affected. We aimed to characterize the COVID-19 impact on NYC resident physicians.METHODS IRB-exempt and expedited cross-sectional analysis through survey to NYC residency program directors April 3–12, 2020, encompassing events from March 2, 2020, to April 12, 2020.RESULTS From an estimated 340 residency programs around NYC, recruitment yielded 91 responses, representing 24 specialties and 2306 residents. In 45.1% of programs, at least 1 resident with confirmed COVID-19 was reported. One hundred one resident physicians were confirmed COVID-19–positive, with an additional 163 residents presumed positive for COVID-19 based on symptoms but awaiting or unable to obtain testing. Two COVID-19–positive residents were hospitalized, with 1 in intensive care. Among specialties with more than 100 residents represented, negative binomial regression indicated that infection risk differed by specialty (P = 0.039). In 80% of programs, quarantining a resident was reported. Ninety of 91 programs reported reuse or extended mask use, and 43 programs reported that personal protective equipment (PPE) was suboptimal. Sixty-five programs (74.7%) redeployed residents elsewhere to support COVID-19 efforts.CONCLUSION Many resident physicians around NYC have been affected by COVID-19 through direct infection, quarantine, or redeployment. Lack of access to testing and concern regarding suboptimal PPE are common among residency programs. Infection risk may differ by specialty.FUNDING National Eye Institute Core Grant P30EY019007; Research to Prevent Blindness Unrestricted Grant; Parker Family Chair; University of Pennsylvania.

Authors

Mark P. Breazzano, Junchao Shen, Aliaa H. Abdelhakim, Lora R. Dagi Glass, Jason D. Horowitz, Sharon X. Xie, C. Gustavo de Moraes, Alice Chen-Plotkin, Royce W.S. Chen, on behalf of the New York City Residency Program Directors COVID-19 Research Group

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Abstract

New York City has been described as the epicenter of the COVID-19 pandemic in the United States. While health care workers are notably at increased risk for COVID-19 infection, the impact on resident physicians remains unclear. In this issue of the JCI, Breazzano et al. surveyed resident physicians for their exposure to COVID-19 during the exponential phase of the COVID-19 pandemic. The researchers also assessed how personal protective equipment and COVID-19 testing protected health care workers from infection. This study highlights resident physician experiences of the first COVID-19 wave that can inform and improve preparedness for upcoming COVID-19 surges and other future epidemics.

Authors

Lauren I. Shapiro, Grace R. Kajita, Julia H. Arnsten, Yaron Tomer

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Abstract

Skeletal muscle depends on the precise orchestration of contractile and metabolic gene expression programs to direct fiber-type specification and to ensure muscle performance. Exactly how such fiber type–specific patterns of gene expression are established and maintained remains unclear, however. Here, we demonstrate that histone monomethyl transferase MLL4 (KMT2D), an enhancer regulator enriched in slow myofibers, plays a critical role in controlling muscle fiber identity as well as muscle performance. Skeletal muscle–specific ablation of MLL4 in mice resulted in downregulation of the slow oxidative myofiber gene program, decreased numbers of type I myofibers, and diminished mitochondrial respiration, which caused reductions in muscle fatty acid utilization and endurance capacity during exercise. Genome-wide ChIP-Seq and mRNA-Seq analyses revealed that MLL4 directly binds to enhancers and functions as a coactivator of the myocyte enhancer factor 2 (MEF2) to activate transcription of slow oxidative myofiber genes. Importantly, we also found that the MLL4 regulatory circuit is associated with muscle fiber–type remodeling in humans. Thus, our results uncover a pivotal role for MLL4 in specifying structural and metabolic identities of myofibers that govern muscle performance. These findings provide therapeutic opportunities for enhancing muscle fitness to combat a variety of metabolic and muscular diseases.

Authors

Lin Liu, Chenyun Ding, Tingting Fu, Zhenhua Feng, Ji-Eun Lee, Liwei Xiao, Zhisheng Xu, Yujing Yin, Qiqi Guo, Zongchao Sun, Wanping Sun, Yan Mao, Likun Yang, Zheng Zhou, Danxia Zhou, Leilei Xu, Zezhang Zhu, Yong Qiu, Kai Ge, Zhenji Gan

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Abstract

γ9δ2T cells play a major role in cancer immune surveillance, yet the clinical translation of their in vitro promise remains challenging. To address limitations of previous clinical attempts using expanded γ9δ2T cells, we explored the clonal diversity of γ9δ2T cell repertoires and characterized their target. We demonstrated that only a fraction of expanded γ9δ2T cells was active against cancer cells and that activity of the parental clone, or functional avidity of selected γ9δ2 T cell receptors (γ9δ2TCRs), was not associated with clonal frequency. Furthermore, we analyzed the target-receptor interface and provided a 2-receptor, 3-ligand model. We found that activation was initiated by binding of the γ9δ2TCR to BTN2A1 through the regions between CDR2 and CDR3 of the TCR γ chain and modulated by the affinity of the CDR3 region of the TCRδ chain, which was phosphoantigen independent (pAg independent) and did not depend on CD277. CD277 was secondary, serving as a mandatory coactivating ligand. We found that binding of CD277 to its putative ligand did not depend on the presence of γ9δ2TCR, did depend on usage of the intracellular CD277, created pAg-dependent proximity to BTN2A1, enhanced cell-cell conjugate formation, and stabilized the immunological synapse (IS). This process critically depended on the affinity of the γ9δ2TCR and required membrane flexibility of the γ9δ2TCR and CD277, facilitating their polarization and high-density recruitment during IS formation.

Authors

Anna Vyborova, Dennis X. Beringer, Domenico Fasci, Froso Karaiskaki, Eline van Diest, Lovro Kramer, Aram de Haas, Jasper Sanders, Anke Janssen, Trudy Straetemans, Daniel Olive, Jeanette Leusen, Lola Boutin, Steven Nedellec, Samantha L. Schwartz, Michael J. Wester, Keith A. Lidke, Emmanuel Scotet, Diane S. Lidke, Albert J.R. Heck, Zsolt Sebestyen, Jürgen Kuball

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Abstract

BACKGROUND Despite an increasing appreciation of the roles that myeloid cells play in tumor progression and therapy, challenges remain in interpreting the tumor-associated myeloid response balance and its translational value. We aimed to construct a simple and reliable myeloid signature for hepatocellular carcinoma (HCC).METHODS Using in situ immunohistochemistry, we assessed the distribution of major myeloid subtypes in both peri- and intratumoral regions of HCC. A 2-feature-based, myeloid-specific prognostic signature, named the myeloid response score (MRS), was constructed using an L1-penalized Cox regression model based on data from a training subset (n = 244), a test subset (n = 244), and an independent internal (n = 341) and 2 external (n = 94; n = 254) cohorts.RESULTS The MRS and the MRS-based nomograms displayed remarkable discriminatory power, accuracy, and clinical usefulness for predicting recurrence and patient survival, superior to current staging algorithms. Moreover, an increase in MRS was associated with a shift in the myeloid response balance from antitumor to protumor activities, accompanied by enhanced CD8+ T cell exhaustion patterns. Additionally, we provide evidence that the MRS was associated with the efficacy of sorafenib treatment for recurrent HCC.CONCLUSION We identified and validated a simple myeloid signature for HCC that showed remarkable prognostic potential and may serve as a basis for the stratification of HCC immune subtypes.FUNDING This work was supported by the National Science and Technology Major Project of China, the National Natural Science Foundation of China, the Science and Information Technology of Guangzhou, the Fundamental Research Funds for the Central Universities, the Guangdong Basic and Applied Basic Research Foundation, and the China Postdoctoral Science Foundation.

Authors

Chong Wu, Jie Lin, Yulan Weng, Dan-Ni Zeng, Jing Xu, Shufeng Luo, Li Xu, Mingyu Liu, Qiaomin Hua, Chao-Qun Liu, Jin-Qing Li, Jing Liao, Cheng Sun, Jian Zhou, Min-Shan Chen, Chao Liu, Zhenhong Guo, Shi-Mei Zhuang, Jin-Hua Huang, Limin Zheng

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Abstract

BACKGROUND Coronavirus disease 19 (COVID-19) is an emerging infectious disease caused by SARS-CoV-2. Antiviral immune response is crucial to achieve pathogen clearance; however, in some patients an excessive and aberrant host immune response can lead to an acute respiratory distress syndrome. The comprehension of the mechanisms that regulate pathogen elimination, immunity, and pathology is essential to better characterize disease progression and widen the spectrum of therapeutic options.METHODS We performed a flow cytometric characterization of immune cell subsets from 30 patients with COVID-19 and correlated these data with clinical outcomes.RESULTS Patients with COVID-19 showed decreased numbers of circulating T, B, and NK cells and exhibited a skewing of CD8+ T cells toward a terminally differentiated/senescent phenotype. In agreement, CD4+ T and CD8+ T, but also NK cells, displayed reduced antiviral cytokine production capability. Moreover, a reduced cytotoxic potential was identified in patients with COVID-19, particularly in those who required intensive care. The latter group of patients also showed increased serum IL-6 levels that inversely correlated to the frequency of granzyme A–expressing NK cells. Off-label treatment with tocilizumab restored the cytotoxic potential of NK cells.CONCLUSION The association between IL-6 serum levels and the impairment of cytotoxic activity suggests the possibility that targeting this cytokine may restore antiviral mechanisms.FUNDING This study was supported by funds from the Department of Experimental and Clinical Medicine of University of Florence (the ex-60% fund and the “Excellence Departments 2018–2022 Project”) derived from Ministero dell’Istruzione, dell’Università e della Ricerca (Italy).

Authors

Alessio Mazzoni, Lorenzo Salvati, Laura Maggi, Manuela Capone, Anna Vanni, Michele Spinicci, Jessica Mencarini, Roberto Caporale, Benedetta Peruzzi, Alberto Antonelli, Michele Trotta, Lorenzo Zammarchi, Luca Ciani, Leonardo Gori, Chiara Lazzeri, Andrea Matucci, Alessandra Vultaggio, Oliviero Rossi, Fabio Almerigogna, Paola Parronchi, Paolo Fontanari, Federico Lavorini, Adriano Peris, Gian Maria Rossolini, Alessandro Bartoloni, Sergio Romagnani, Francesco Liotta, Francesco Annunziato, Lorenzo Cosmi

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Abstract

Oxidant stress can contribute to health and disease. Here we show that invertebrates and vertebrates share a common stereospecific redox pathway that protects against pathological responses to stress, at the cost of reduced physiological performance, by constraining Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity. MICAL1, a methionine monooxygenase thought to exclusively target actin, and MSRB, a methionine reductase, control the stereospecific redox status of M308, a highly conserved residue in the calmodulin-binding (CaM-binding) domain of CaMKII. Oxidized or mutant M308 (M308V) decreased CaM binding and CaMKII activity, while absence of MICAL1 in mice caused cardiac arrhythmias and premature death due to CaMKII hyperactivation. Mimicking the effects of M308 oxidation decreased fight-or-flight responses in mice, strikingly impaired heart function in Drosophila melanogaster, and caused disease protection in human induced pluripotent stem cell–derived cardiomyocytes with catecholaminergic polymorphic ventricular tachycardia, a CaMKII-sensitive genetic arrhythmia syndrome. Our studies identify a stereospecific redox pathway that regulates cardiac physiological and pathological responses to stress across species.

Authors

Klitos Konstantinidis, Vassilios J. Bezzerides, Lo Lai, Holly M. Isbell, An-Chi Wei, Yuejin Wu, Meera C. Viswanathan, Ian D. Blum, Jonathan M. Granger, Danielle Heims-Waldron, Donghui Zhang, Elizabeth D. Luczak, Kevin R. Murphy, Fujian Lu, Daniel H. Gratz, Bruno Manta, Qiang Wang, Qinchuan Wang, Alex L. Kolodkin, Vadim N. Gladyshev, Thomas J. Hund, William T. Pu, Mark N. Wu, Anthony Cammarato, Mario A. Bianchet, Madeline A. Shea, Rodney L. Levine, Mark E. Anderson

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Abstract

Desmoplasia describes the deposition of extensive extracellular matrix and defines primary pancreatic ductal adenocarcinoma (PDA). The acellular component of this stroma has been implicated in PDA pathogenesis and is being targeted therapeutically in clinical trials. By analyzing the stromal content of PDA samples from numerous annotated PDA data sets and correlating stromal content with both anatomic site and clinical outcome, we found PDA metastases in the liver, the primary cause of mortality to have less stroma, have higher tumor cellularity than primary tumors. Experimentally manipulating stromal matrix with an anti– lysyl oxidase like-2 (anti-LOXL2) antibody in syngeneic orthotopic PDA mouse models significantly decreased matrix content, led to lower tissue stiffness, lower contrast retention on computed tomography, and accelerated tumor growth, resulting in diminished overall survival. These studies suggest an important protective role of stroma in PDA and urge caution in clinically deploying stromal depletion strategies.

Authors

Honglin Jiang, Robert J. Torphy, Katja Steiger, Henry Hongo, Alexa J. Ritchie, Mark Kriegsmann, David Horst, Sarah E. Umetsu, Nancy M. Joseph, Kimberly McGregor, Michael J. Pishvaian, Edik M. Blais, Brian Lu, Mingyu Li, Michael Hollingsworth, Connor Stashko, Keith Volmar, Jen Jen Yeh, Valerie M. Weaver, Zhen J. Wang, Margaret A. Tempero, Wilko Weichert, Eric A. Collisson

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Abstract

Authors

Ralph J. DeBerardinis

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Abstract

The origin and fate of renal myofibroblasts is not clear after acute kidney injury (AKI). Here, we demonstrate that myofibroblasts were activated from quiescent pericytes (qPericytes) and the cell numbers increased after ischemia/reperfusion injury–induced AKI (IRI-AKI). Myofibroblasts underwent apoptosis during renal recovery but one-fifth of them survived in the recovered kidneys on day 28 after IRI-AKI and their cell numbers increased again after day 56. Microarray data showed the distinctive gene expression patterns of qPericytes, activated pericytes (aPericytes, myofibroblasts), and inactivated pericytes (iPericytes) isolated from kidneys before, on day 7, and on day 28 after IRI-AKI. Hypermethylation of the Acta2 repressor Ybx2 during IRI-AKI resulted in epigenetic modification of iPericytes to promote the transition to chronic kidney disease (CKD) and aggravated fibrogenesis induced by a second AKI induced by adenine. Mechanistically, transforming growth factor-β1 decreased the binding of YBX2 to the promoter of Acta2 and induced Ybx2 hypermethylation, thereby increasing α-smooth muscle actin expression in aPericytes. Demethylation by 5-azacytidine recovered the microvascular stabilizing function of aPericytes, reversed the profibrotic property of iPericytes, prevented AKI-CKD transition, and attenuated fibrogenesis induced by a second adenine-AKI. In conclusion, intervention to erase hypermethylation of pericytes after AKI provides a strategy to stop the transition to CKD.

Authors

Yu-Hsiang Chou, Szu-Yu Pan, Yu-Han Shao, Hong-Mou Shih, Shi-Yao Wei, Chun-Fu Lai, Wen-Chih Chiang, Claudia Schrimpf, Kai-Chien Yang, Liang-Chuan Lai, Yung-Ming Chen, Tzong-Shinn Chu, Shuei-Liong Lin

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Abstract

Although broadly protective, stem-targeted Abs against the influenza A virus hemagglutinin (HA) have been well studied, very limited information is available on Abs that broadly recognize the head domain. We determined the crystal structure of the HA protein of the avian H7N9 influenza virus in complex with a pan-H7, non-neutralizing, protective human Ab. The structure revealed a B cell epitope in the HA head domain trimer interface (TI). This discovery of a second major protective TI epitope supports a model in which uncleaved HA trimers exist on the surface of infected cells in a highly dynamic state that exposes hidden HA head domain features.

Authors

Jinhui Dong, Iuliia Gilchuk, Sheng Li, Ryan Irving, Matthew T. Goff, Hannah L. Turner, Andrew B. Ward, Robert H. Carnahan, James E. Crowe Jr.

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Abstract

FTY720 is a treatment for relapsing remitting multiple sclerosis (MS). It is an analog of sphingosine-1-phosphate (S1P) and targets S1P receptors 1, 3, 4, and 5. Recent reports indicate an association between long-term exposure to FTY720 and cases of cryptococcal infection. Here, we studied the effect of FTY720 and its derivative, BAF312, which only target S1P receptors 1 and 5, in a mouse model of cryptococcal infection. We found that treatment with FTY720, but not with BAF312, led to decreased survival and increased organ burden in mouse cryptococcal granulomas. Both FTY720 and BAF312 caused a profound CD4+ and CD8+ T cell depletion in blood and lungs but only treatment with FTY720 led to cryptococcal reactivation. Treatment with FTY720, but not with BAF312, was associated with disorganization of macrophages and with M2 polarization at the granuloma site. In a cell system, FTY720 decreased phagocytosis and production of reactive oxygen species by macrophages, a phenotype recapitulated in the S1pr3–/– knockout macrophages. Our results suggest that FTY720 reactivates cryptococcosis from the granuloma through a S1P receptor 3–mediated mechanism and support the rationale for development of more-specific receptor modulators for therapeutic use of MS.

Authors

Arielle M. Bryan, Jeehyun Karen You, Travis McQuiston, Cristina Lazzarini, Zhijuan Qiu, Brian Sheridan, Barbara Nuesslein-Hildesheim, Maurizio Del Poeta

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Abstract

Graft-versus-host disease (GVHD) remains an important cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HCT). For decades, GVHD prophylaxis has included calcineurin inhibitors, despite their incomplete efficacy and impairment of graft-versus-leukemia (GVL). Distinct from pharmacologic immune suppression, we have developed what we believe is a novel, human CD83-targeted chimeric antigen receptor (CAR) T cell for GVHD prevention. CD83 is expressed on allo-activated conventional CD4+ T cells (Tconvs) and proinflammatory dendritic cells (DCs), which are both implicated in GVHD pathogenesis. Human CD83 CAR T cells eradicate pathogenic CD83+ target cells, substantially increase the ratio of regulatory T cells (Tregs) to allo-activated Tconvs, and provide durable prevention of xenogeneic GVHD. CD83 CAR T cells are also capable of treating xenogeneic GVHD. We show that human acute myeloid leukemia (AML) expresses CD83 and that myeloid leukemia cell lines are readily killed by CD83 CAR T cells. Human CD83 CAR T cells are a promising cell-based approach to preventing 2 critical complications of allo-HCT — GVHD and relapse. Thus, the use of human CD83 CAR T cells for GVHD prevention and treatment, as well as for targeting CD83+ AML, warrants clinical investigation.

Authors

Bishwas Shrestha, Kelly Walton, Jordan Reff, Elizabeth M. Sagatys, Nhan Tu, Justin Boucher, Gongbo Li, Tayyebb Ghafoor, Martin Felices, Jeffrey S. Miller, Joseph Pidala, Bruce R. Blazar, Claudio Anasetti, Brian C. Betts, Marco L. Davila

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Abstract

Peripheral neurotoxicity is a debilitating condition that afflicts up to 90% of patients with colorectal cancer receiving oxaliplatin-containing therapy. Although emerging evidence has highlighted the importance of various solute carriers to the toxicity of anticancer drugs, the contribution of these proteins to oxaliplatin-induced peripheral neurotoxicity remains controversial. Among candidate transporters investigated in genetically engineered mouse models, we provide evidence for a critical role of the organic cation transporter 2 (OCT2) in satellite glial cells in oxaliplatin-induced neurotoxicity, and demonstrate that targeting OCT2 using genetic and pharmacological approaches ameliorates acute and chronic forms of neurotoxicity. The relevance of this transport system was verified in transporter-deficient rats as a secondary model organism, and translational significance of preventive strategies was demonstrated in preclinical models of colorectal cancer. These studies suggest that pharmacological targeting of OCT2 could be exploited to afford neuroprotection in cancer patients requiring treatment with oxaliplatin.

Authors

Kevin M. Huang, Alix F. Leblanc, Muhammad Erfan Uddin, Ji Young Kim, Mingqing Chen, Eric D. Eisenmann, Alice A. Gibson, Yang Li, Kristen W. Hong, Duncan DiGiacomo, Sherry H. Xia, Paola Alberti, Alessia Chiorazzi, Stephen N. Housley, Timothy C. Cope, Jason A. Sprowl, Jing Wang, Charles L. Loprinzi, Anne Noonan, Maryam B. Lustberg, Guido Cavaletti, Navjot Pabla, Shuiying Hu, Alex Sparreboom

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Abstract

Myelopoiesis is invariably present and contributes to pathology in animal models of graft-versus-host disease (GVHD). In humans, a rich inflammatory infiltrate bearing macrophage markers has also been described in histological studies. In order to determine the origin, functional properties, and role in pathogenesis of these cells, we isolated single-cell suspensions from acute cutaneous GVHD and subjected them to genotype, transcriptome, and in vitro functional analysis. A donor-derived population of CD11c+CD14+ cells was the dominant population of all leukocytes in GVHD. Surface phenotype and NanoString gene expression profiling indicated the closest steady-state counterpart of these cells to be monocyte-derived macrophages. In GVHD, however, there was upregulation of monocyte antigens SIRPα and S100A8/9 transcripts associated with leukocyte trafficking, pattern recognition, antigen presentation, and costimulation. Isolated GVHD macrophages stimulated greater proliferation and activation of allogeneic T cells and secreted higher levels of inflammatory cytokines than their steady-state counterparts. In HLA-matched mixed leukocyte reactions, we also observed differentiation of activated macrophages with a similar phenotype. These exhibited cytopathicity to a keratinocyte cell line and mediated pathological damage to skin explants independently of T cells. Together, these results define the origin, functional properties, and potential pathogenic roles of human GVHD macrophages.

Authors

Laura Jardine, Urszula Cytlak, Merry Gunawan, Gary Reynolds, Kile Green, Xiao-Nong Wang, Sarah Pagan, Maharani Paramitha, Christopher A. Lamb, Anna K. Long, Erin Hurst, Smeera Nair, Graham H. Jackson, Amy Publicover, Venetia Bigley, Muzlifah Haniffa, A.J. Simpson, Matthew Collin

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Abstract

Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT). Donor T cells are key mediators in pathogenesis, but a contribution from host T cells has not been explored, as conditioning regimens are believed to deplete host T cells. To evaluate a potential role for host T cells in GVHD, the origin of skin and blood T cells was assessed prospectively in patients after HSCT in the absence of GVHD. While blood contained primarily donor-derived T cells, most T cells in the skin were host derived. We next examined patient skin, colon, and blood during acute GVHD. Host T cells were present in all skin and colon acute GVHD specimens studied, yet were largely absent in blood. We observed acute skin GVHD in the presence of 100% host T cells. Analysis demonstrated that a subset of host T cells in peripheral tissues were proliferating (Ki67+) and producing the proinflammatory cytokines IFN-γ and IL-17 in situ. Comparatively, the majority of antigen-presenting cells (APCs) in tissue in acute GVHD were donor derived, and donor-derived APCs were observed directly adjacent to host T cells. A humanized mouse model demonstrated that host skin-resident T cells could be activated by donor monocytes to generate a GVHD-like dermatitis. Thus, host tissue-resident T cells may play a previously unappreciated pathogenic role in acute GVHD.

Authors

Sherrie J. Divito, Anders T. Aasebø, Tiago R. Matos, Pei-Chen Hsieh, Matthew Collin, Christopher P. Elco, John T. O’Malley, Espen S. Bækkevold, Henrik Reims, Tobias Gedde-Dahl, Michael Hagerstrom, Jude Hilaire, John W. Lian, Edgar L. Milford, Geraldine S. Pinkus, Vincent T. Ho, Robert J. Soiffer, Haesook T. Kim, Martin C. Mihm, Jerome Ritz, Indira Guleria, Corey S. Cutler, Rachael A. Clark, Frode L. Jahnsen, Thomas S. Kupper

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Abstract

Th cells integrate signals from their microenvironment to acquire distinct specialization programs for efficient clearance of diverse pathogens or for immunotolerance. Ionic signals have recently been demonstrated to affect T cell polarization and function. Sodium chloride (NaCl) was proposed to accumulate in peripheral tissues upon dietary intake and to promote autoimmunity via the Th17 cell axis. Here, we demonstrate that high-NaCl conditions induced a stable, pathogen-specific, antiinflammatory Th17 cell fate in human T cells in vitro. The p38/MAPK pathway, involving NFAT5 and SGK1, regulated FoxP3 and IL-17A expression in high-NaCl conditions. The NaCl-induced acquisition of an antiinflammatory Th17 cell fate was confirmed in vivo in an experimental autoimmune encephalomyelitis (EAE) mouse model, which demonstrated strongly reduced disease symptoms upon transfer of T cells polarized in high-NaCl conditions. However, NaCl was coopted to promote murine and human Th17 cell pathogenicity, if T cell stimulation occurred in a proinflammatory and TGF-β–low cytokine microenvironment. Taken together, our findings reveal a context-dependent, dichotomous role for NaCl in shaping Th17 cell pathogenicity. NaCl might therefore prove beneficial for the treatment of chronic inflammatory diseases in combination with cytokine-blocking drugs.

Authors

Julia Matthias, Sylvia Heink, Felix Picard, Julia Zeiträg, Anna Kolz, Ying-Yin Chao, Dominik Soll, Gustavo P. de Almeida, Elke Glasmacher, Ilse D. Jacobsen, Thomas Riedel, Anneli Peters, Stefan Floess, Jochen Huehn, Dirk Baumjohann, Magdalena Huber, Thomas Korn, Christina E. Zielinski

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Abstract

Breast cancer stem cells (BCSCs) play a critical role in cancer recurrence and metastasis. Chemotherapy induces BCSC specification through increased expression of pluripotency factors, but how their expression is regulated is not fully understood. Here, we delineate a pathway controlled by hypoxia-inducible factor 1 (HIF-1) that epigenetically activates pluripotency factor gene transcription in response to chemotherapy. Paclitaxel induces HIF-1–dependent expression of S100A10, which forms a complex with ANXA2 that interacts with histone chaperone SPT6 and histone demethylase KDM6A. S100A10, ANXA2, SPT6, and KDM6A are recruited to OCT4 binding sites and KDM6A erases H3K27me3 chromatin marks, facilitating transcription of genes encoding the pluripotency factors NANOG, SOX2, and KLF4, which along with OCT4 are responsible for BCSC specification. Silencing of S100A10, ANXA2, SPT6, or KDM6A expression blocks chemotherapy-induced enrichment of BCSCs, impairs tumor initiation, and increases time to tumor recurrence after chemotherapy is discontinued. Pharmacological inhibition of KDM6A also impairs chemotherapy-induced BCSC enrichment. These results suggest that targeting HIF-1/S100A10–dependent and KDM6A-mediated epigenetic activation of pluripotency factor gene expression in combination with chemotherapy may block BCSC enrichment and improve clinical outcome.

Authors

Haiquan Lu, Yangyiran Xie, Linh Tran, Jie Lan, Yongkang Yang, Naveena L. Murugan, Ru Wang, Yueyang J. Wang, Gregg L. Semenza

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Abstract

Convalescent plasma is a leading treatment for COVID-19, but there is a paucity of data identifying therapeutic efficacy. Among 126 potential convalescent plasma donors, the humoral immune response was evaluated by a SARS-CoV-2 virus neutralization assay using Vero-E6-TMPRSS2 cells, commercial IgG and IgA ELISA to spike(S) protein S1 domain (Euroimmun), IgA, IgG and IgM indirect ELISAs to the full-length S or S-receptor binding domain(S-RBD), and an IgG avidity assay. Multiple linear regression and predictive models were utilized to assess the correlations between antibody responses with demographic and clinical characteristics. IgG titers were greater than either IgM or IgA for S1, full length S, and S-RBD in the overall population. Of the 126 plasma samples, 101(80%) had detectable neutralizing antibody(nAb) titers. Using nAb titers as the reference, the IgG ELISAs confirmed between 95-98% of the nAb positive, but only 20-32% of the nAb negative samples. Male sex, older age, and hospitalization with COVID-19 were associated with increased antibody responses across the serological assays. There was substantial heterogeneity in the antibody response among potential convalescent plasma donors, but sex, age, and hospitalization emerged as factors that can be used to identify individuals with a high likelihood of having strong antiviral antibody responses.

Authors

Sabra L. Klein, Andrew Pekosz, Han-Sol Park, Rebecca L. Ursin, Janna R. Shapiro, Sarah E. Benner, Kirsten Littlefield, Swetha Kumar, Harnish Mukesh Naik, Michael Betenbaugh, Ruchee Shrestha, Annie A. Wu, Robert M. Hughes, Imani Burgess, Patrizio Caturegli, Oliver Laeyendecker, Thomas C. Quinn, David J. Sullivan, Shmuel Shoham, Andrew D. Redd, Evan M. Bloch, Arturo Casadevall, Aaron A. R. Tobian

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Abstract

Emerging data indicate that complement and neutrophils contribute to the maladaptive immune response that fuels hyper-inflammation and thrombotic microangiopathy, thereby increasing COVID-19 mortality. Here, we investigated how complement interacts with the platelet/neutrophil extracellular traps (NETs)/thrombin axis, using COVID-19 specimens, cell-based inhibition studies and NETs/human aortic endothelial cell (HAEC) co-cultures. Increased plasma levels of NETs, tissue factor (TF) activity and sC5b-9 were detected in patients. Neutrophils of patients yielded high TF expression and released NETs carrying active TF. Treatment of control neutrophils with COVID-19 platelet-rich plasma generated TF-bearing NETs that induced thrombotic activity of HAEC. Thrombin or NETosis inhibition or C5aR1 blockade attenuated platelet-mediated NET-driven thrombogenicity. COVID-19 serum induced complement activation in vitro, consistent with high complement activity in clinical samples. Complement C3 inhibition with compstatin Cp40 disrupted TF expression in neutrophils. In conclusion, we provide a mechanistic basis for a pivotal role of complement and NETs in COVID-19 immunothrombosis. This study supports strategies against SARS-CoV-2 that exploit complement or NETosis inhibition.

Authors

Panagiotis Skendros, Alexandros Mitsios, Akrivi Chrysanthopoulou, Dimitrios C. Mastellos, Simeon Metallidis, Petros Rafailidis, Maria Ntinopoulou, Eleni Sertaridou, Victoria Tsironidou, Christina Tsigalou, Maria G. Tektonidou, Theocharis Konstantinidis, Charalampos Papagoras, Ioannis Mitroulis, Georgios Germanidis, John D. Lambris, Konstantinos Ritis

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Abstract

Mitochondria have emerged as key actors of innate and adaptive immunity. Mitophagy has a pivotal role in cell homeostasis but its contribution to macrophage functions and host defense remains to be delineated. Here we showed that lipopolysaccharide (LPS) in combination with IFNγ, inhibits PINK1-dependent mitophagy in macrophages through a STAT1-dependent activation of the inflammatory caspases 1 and 11. In addition, we demonstrated that the inhibition of mitophagy triggers classical macrophage activation in a mitochondrial ROS-dependent manner. In a murine model of polymicrobial infection (cecal ligature and puncture, CLP), adoptive transfer of Pink1-deficient bone marrow or pharmacological inhibition of mitophagy promoted macrophage activation which favored bactericidal clearance and lead to a better survival. Reciprocally, mitochondrial uncouplers, that promote mitophagy, reverse LPS/IFNγ-mediated activation of macrophages and lead to immuno-paralysis with impaired bacterial clearance and lowered survival. In critically ill patients, we showed that mitophagy is inhibited in blood monocytes of patients with sepsis as compared to non-septic patients. Overall, this work demonstrates that the inhibition of mitophagy is a physiological mechanism that contributes to the activation of myeloid cells and improves the outcome of sepsis.

Authors

Danish Patoli, Franck Mignotte, Valérie Deckert, Alois Dusuel, Adelie Dumont, Aurelie Rieu, Antoine Jalil, Kevin Van Dongen, Thibaut Bourgeois, Thomas Gautier, Charlene Magnani, Naig Le Guern, Stéphane Mandard, Jean Bastin, Fatima Djouadi, Christine Schaeffer, Nina Guillaumot, Michel Narce, Maxime Nguyen, Julien Guy, Auguste Dargent, Jean-Pierre Quenot, Mickaël Rialland, David Masson, Johan Auwerx, Laurent Lagrost, Charles Thomas

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Abstract

The liver has strong innate immunity to counteract pathogens from the gastrointestinal tract. During the development of liver cancer, which is typically driven by chronic inflammation, the composition and biological roles of the innate immune cells are extensively altered. Hypoxia is a common finding in all stages of liver cancer development. Hypoxia drives the stabilization of hypoxia-inducible factors (HIFs), which act as central regulators to dampen the innate immunity of liver cancer. HIF signaling in innate immune cells and liver cancer cells together favor the recruitment and maintenance of pro-tumorigenic immune cells and the inhibition of anti-tumorigenic immune cells, promoting immune evasion. HIFs represent attractive therapeutic targets to inhibit the formation of an immunosuppressive microenvironment and growth of liver cancer.

Authors

Vincent Wai-Hin Yuen, Carmen Chak-Lui Wong

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Abstract

Although IKK-β has previously been shown as a negative regulator of IL-1β secretion in mice, this role has not been demonstrated in humans. Genetic studies of NF-κB signalling in humans with inherited diseases of the immune system have not demonstrated the relevance of the NF-κB pathway in suppression of IL-1β expression. Here, we report an infant displaying clinical pathology comprising neutrophil-mediated auto-inflammation and recurrent bacterial infections. Whole-exome sequencing revealed a de novo heterozygous missense mutation in NFKBIA, resulting in a L34P IκBα variant, that severely repressed NF-κB activation and downstream cytokine production. Paradoxically, IL-1β secretion was elevated in the patient’s stimulated leukocytes, in her induced-pluripotent stem cell-derived macrophages, and in murine bone marrow-derived macrophages containing the L34P mutation. The patient’s hyper-IL-1β secretion correlated with activated neutrophilia and liver fibrosis with neutrophil accumulation. Hematopoietic stem cell transplantation reversed neutrophilia, restored a resting state in neutrophils, and normalized IL-1β release from stimulated leukocytes. Additional therapeutic blockade of IL-1 ameliorated liver damage, whilst decreasing neutrophil activation and associated IL-1β secretion. Our studies reveal a previously unrecognized role of human IκBα as an essential regulator of canonical NF-κB signalling in the prevention of neutrophilic-dependent auto-inflammatory diseases. We showed that IκBα controls IL-1β secretion through a mechanism of self-limiting post-transcriptional regulation. These findings also highlight a therapeutic potential for IL-1 inhibitors to treat complications arising from systemic NF-κB inhibition.

Authors

Enrica Ee Kar Tan, Richard Hopkins, Chrissie K. Lim, Saumya Jamuar, Christina Ong, Koh Cheng Thoon, Mark J.A. Koh, Eun Myoung Shin, Derrick Wen Quan Lian, Madhushanee Weerasooriya, Christopher Z.W Lee, Andreas Alvin Purnomo Soetedjo, Chang Siang Lim, Veronica B. Au, WM Edmond Chua, Hui Yin Lee, Leigh Ann Jones, Sharmy Jennifer James, Nivashini Kaliaperumal, Jeffrey Kwok, Ee Shien Tan, Biju Thomas, Lena Ho, Lynn Wu, Anna-Marie Fairhurst, Florent Ginhoux, Adrian K.K. Teo, Yongliang Zhang, Kok Haur Ong, Weimiao Yu, Byrappa Venkatesh, Vinay Tergaonkar, Bruno Reversade, Keh-Chuang Chin, Ah Moy Tan, Woei Kang Liew, John E. Connolly

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August 2020

August 2020 Issue

On the cover:
“Burst of Passion II” characterizes dynamic transcriptional machinery

Prostate cancer is associated with dysregulated gene expression, but how the chromatin landscape influences RNA Polymerase II (RNA Pol II) and transcriptional output remains unclear. In this issue of the JCI, Ramanand, Chen, Yuan, and colleagues mapped the RNA Pol II/chromatin interaction of healthy or cancerous prostate cell lines. The researchers used a modified paired-end tag sequencing technique to immunoprecipitate chromatin from crosslinked cells. They revealed thousands of protein-DNA and DNA-DNA interactions. This study highlights the importance of genome structure and transcriptional dysregulation in prostate cancer. The cover image ‘Burst of Passion II’ by artist Ken Bonner exemplifies the coordinated and dynamic nature of transcriptional machinery. Image credit: Ken Bonner.

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August 2020 JCI This Month

JCI This Month is a digest of the research, reviews, and other features published each month.

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Review Series - More

Latency in Infectious Disease

Series edited by Arturo Casadevall

Latency describes the persistence of a microorganism within its host in the absence of clinical symptoms of disease. Both microorganism and host benefit from induction of latency: the microorganism establishes a stable environment that facilitates survival, and the host avoids progressive damage and disease. Latent states have been observed in bacterial, viral, fungal, and parasitic infectious diseases, though the mechanisms differ within each microorganism and host pair. In this issue, a Review Series on Latency in Infectious Disease explores the different strategies that various microorganisms use to achieve latency. Conceptualized by JCI’s Deputy Editor Arturo Casadevall, the series highlights the latency mechanisms employed by herpesviruses, HIV, Cryptococcus neoformans, and Toxoplasma gondii. In addition to describing mechanisms, the reviews outline the detrimental effects of latent disease and recent progress toward treatment and eradication.

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