Research
Abstract
Pre-existing cross-reactivity to SARS-CoV-2 may occur in absence of prior viral exposure. However, this has been difficult to quantify at the population level due to a lack of reliably defined seroreactivity thresholds. Using an orthogonal antibody testing approach, we estimated that ~0.6% of non-triaged adults from the greater Vancouver area, Canada between May 17th and June 19th 2020 showed clear evidence of a prior SARS-CoV-2 infection, after adjusting for false-positive and false-negative test results. Using a highly sensitive multiplex assay and positive/negative thresholds established in infants in whom maternal antibodies have waned, we determine that more than 90% of uninfected adults showed antibody reactivity against the spike, receptor-binding domain (RBD), N-terminal domains (NTD) or the nucleocapsid (N) protein from SARS-CoV-2. This sero-reactivity was evenly distributed across age and sex, correlated with circulating coronaviruses reactivity, and was partially outcompeted by soluble circulating coronaviruses’ spike. Using a custom SARS-CoV-2 peptide mapping array, we found that this antibody reactivity broadly mapped to spike, and to conserved non-structural viral proteins. We conclude that most adults display pre-existing antibody cross-reactivity against SARS-CoV-2, which further supports investigation of how this may impact the clinical severity of COVID-19 or SARS-CoV-2 vaccine responses.
Authors
Abdelilah Majdoubi, Christina Michalski, Sarah E. O’Connell, Sarah Dada, Sandeep R. Narpala, Jean P. Gelinas, Disha Mehta, Claire Cheung, Dirk F.H. Winkler, Manjula Basappa, Aaron C. Liu, Matthias Görges, Vilte E. Barakauskas, Michael A. Irvine, Jennifer Mehalko, Dominic Esposito, Inna Sekirov, Agatha N. Jassem, David M. Goldfarb, Steven Pelech, Daniel C. Douek, Adrian B. McDermott, Pascal M Lavoie
Abstract
Compromised regenerative capacity of lung epithelial cells can lead to cellular senescence, which may precipitate fibrosis. While increased markers of senescence have been reported in idiopathic pulmonary fibrosis (IPF), the origin and identity of these senescent cells remain unclear, and tools to characterize context-specific cellular senescence in human lung are lacking. We observed that the senescent marker p16 is predominantly localized to bronchiolized epithelial structures in scarred regions of IPF and systemic sclerosis associated interstitial lung disease ILD (SSc-ILD) lung tissue, overlapping with the basal epithelial markers Keratin 5 and Keratin 17. Using in vitro models, we derived transcriptional signatures of senescence programming specific to different types of lung epithelial cells, and interrogated these signatures in a single-cell RNA-seq data set derived from control, IPF, and SSc-ILD lung tissue. We identified a population of basal epithelial cells defined by, and enriched for, markers of cellular senescence, and identified candidate markers specific to senescent basal epithelial cells in ILD that can enable future functional studies. Notably, gene expression of these cells significantly overlaps with terminally differentiating cells in stratified epithelia, where it is driven by p53 activation as part of the senescence program.
Authors
Daryle J. DePianto, Jason A. Vander Heiden, Katrina B. Morshead, Kai-Hui Sun, Zora Modrusan, Grace Teng, Paul J. Wolters, Joseph R. Arron
Abstract
Currently, no effective therapies exist for fibrodysplasia ossificans progressiva (FOP), a rare congenital syndrome in which heterotopic bone is formed in soft tissues due to dysregulated activity of the bone morphogenetic protein (BMP) receptor kinase ALK2/ACVR1. From a screen of known biologically active compounds, we identified saracatinib as a potent ALK2 kinase inhibitor. In enzymatic and cell-based assays, saracatinib preferentially inhibited ALK2 compared with other receptors of the BMP/TGFb signaling pathway, and induced dorsalization in zebrafish embryos consistent with BMP antagonism. We further tested the efficacy of saracatinib using an inducible ACVR1Q207D transgenic mouse line, which provides a model of heterotopic ossification, as well as an inducible ACVR1R206H knock-in, which serves as a genetically and physiologically faithful model of FOP. In both models, saracatinib was well tolerated and potently inhibited the development of heterotopic ossification even when administered transiently following soft tissue injury. Together, these data suggest that saracatinib is an efficacious clinical candidate for repositioning in the treatment of FOP, offering an accelerated path to clinical proof of efficacy studies and potentially significant benefits to individuals with this devastating condition.
Authors
Eleanor P. Williams, Jana Bagarova, Georgina Kerr, Dong-Dong Xia, Elsie S. Place, Devaveena Dey, Yue Shen, Geoffrey A. Bocobo, Agustin H. Mohedas, Xiuli Huang, Philip E. Sanderson, Arthur Lee, Wei Zheng, Aris N. Economides, James C. Smith, Paul B. Yu, Alex N. Bullock
Abstract
The increased incidence of whooping cough worldwide suggests that current vaccination against Bordetella pertussis infection has limitations in quality and duration of protection. The resurgence of infection has been linked to the introduction of acellular vaccines (aP) which has an improved safety profile compared to the previously used whole-cell (wP) vaccines. To determine immunological differences between aP vs. wP priming in infancy, we performed a systems approach of the immune response to booster vaccination. Transcriptomic, proteomic, cytometric, and serologic profiling revealed multiple shared immune responses with different kinetics across cohorts, including an increase of blood monocyte frequencies, and strong antigen-specific IgG responses. Additionally, we found a prominent subset of aP-primed individuals (30%) with a strong differential signature, including higher levels of expression for CCL3, NFKBIA, and ICAM1. Contrary to the wP individuals, this subset displayed increased PT-specific IgE responses postboost and higher antigen-specific IgG4 and IgG3 antibodies against FHA and FIM2/3 at baseline and post-boost. Overall, the results show that, while broad immune response patterns to Tdap boost overlap between aP- and wP-primed individuals, a subset of aP-primed individuals present a divergent response. These findings provide candidate targets to study the causes and correlates of waning immunity after aP vaccination.
Authors
Ricardo da Silva Antunes, Ferran Soldevila, Mikhail Pomaznoy, Mariana Babor, Jason Bennett, Yuan Tian, Natalie N. Khalil, Yu Qian, Aishwarya Mandava, Richard H. Scheuermann, Mario Cortese, Bali Pulendran, Christopher D. Petro, Adrienne P. Gilkes, Lisa A. Purcell, Alessandro Sette, Bjoern Peters
Abstract
Vaccine delivery technologies are mainly designed to minimally invasively deliver vaccines to target tissues with little or no adjuvant effects. This study presents a prototype laser-based powder delivery (LPD) with inherent adjuvant effects for more immunogenic vaccination without incorporation of external adjuvants. LPD takes advantage of aesthetic ablative fractional laser to generate skin microchannels to support high-efficient vaccine delivery and at the same time creates photothermal stress in microchannel-surrounding tissues to boost vaccination. LPD could significantly enhance pandemic influenza 2009 H1N1 vaccine immunogenicity and protective efficacy as compared to needle-based intradermal delivery in murine models. The ablative fractional laser was found to induce host DNA release, activate NLR family pyrin domain containing 3 (NLRP3) inflammasome, and stimulate interleukin 1β release despite of their dispensability for laser adjuvant effects. Instead, the ablative fractional laser activated MyD88 to mediate its adjuvant effects by potentiation of antigen uptake, maturation, and migration of dendritic cells. LPD also induced minimal local or systemic adverse reactions due to the micro-fractional and sustained vaccine delivery. Our data support the development of self-adjuvanted vaccine delivery technologies by intentional induction of well-controlled tissue stress to alert innate immune systems for more immunogenic vaccination.
Authors
Zhuofan Li, Yan Cao, Yibo Li, Yiwen Zhao, Xinyuan Chen
Abstract
Both innate and adaptive immune cells are critical players in autoimmune destruction of insulin-producing β-cells in type 1 diabetes. However, the early pathogenic events triggering the recruitment and activation of innate immune cells in islets remain obscure. Here we show that circulating fatty acid binding protein 4 (FABP4) level is significantly elevated in type1 diabetes patients and their first-degree relatives, and positively correlates with the titers of several islet autoantibodies. In non-obese diabetic (NOD) mice, increased FABP4 expression in islet macrophages starts from the neonatal period, well before the occurrence of overt diabetes. Furthermore, the spontaneous development of autoimmune diabetes in NOD mice is markedly reduced by pharmacological inhibition or genetic ablation of FABP4, or adoptive transfer of FABP4-deficient bone marrow cells. Mechanistically, FABP4 activates innate immune responses in islets by enhancing the infiltration and polarization of macrophages to pro-inflammatory M1 subtype, thus creating an inflammatory milieu required for activation of diabetogenic CD8+ T cells and shift of CD4+ helper T cells towards the Th1 subtypes. These findings demonstrate FABP4 as an early mediator for β-cell autoimmunity by facilitating crosstalk between innate and adaptive immune cells, suggesting that pharmacological inhibition of FABP4 may represent a promising therapeutic strategy for autoimmune diabetes.
Authors
Yang Xiao, Lingling Shu, Xiaoping Wu, Yang Liu, Lai Yee Cheong, Boya Liao, Xiaoyu Xiao, Ruby L.C. Hoo, Zhiguang Zhou, Aimin Xu
Abstract
AbstractMillions of people are affected by hearing loss. When hearing loss is caused by noise or aging, it is often associated with breakdown of the barrier between the cochlea and its blood vessels. Pericytes populate many small vessels in the adult inner ear, however, their role in different forms of hearing loss is largely unknown. Using an inducible and conditional pericyte depletion mouse model, we show that loss of pericytes leads to marked changes in vascular structure, resulting in poor blood circulation and hearing loss. In vitro, using advanced tissue explants from pericyte fluorescence reporter models in combination with exogenous donor pericytes, we show pericytes, signaled by endothelial growth factor isoform A165 (VEGF-A165), vigorously drives new vessel growth in both adult and neonatal mouse inner ear tissue. In vivo, the delivery of an adeno-associated virus serotype 1 (AAV1)-mediated VEGF-A165 viral vector to pericyte depleted animals regenerated lost pericytes, improved blood supply, reduced loss of sensory hair cells, and attenuated hearing loss. These studies provide the first clear-cut evidence that pericytes are critical for adult hearing and can regenerate cochlear vasculature. The restoration of vascular function in the damaged inner ear with AAV1-mediated VEGF-A165 gene therapy is a new strategy for ameliorating vascular associated hearing disorders, including common forms of age-related hearing loss.
Authors
Jinhui Zhang, Zhiqiang Hou, Xiaohan Wang, Han Jiang, Lingling Neng, Yunpei Zhang, Qing Yu, George W. S. Burwood, Junha Song, Manfred Auer, Anders Fridberger, Michael Hoa, Xiaorui Shi
Abstract
Liver regeneration is critical to survival after traumatic injuries, exposure to hepatotoxins, or surgical interventions, yet the underlying signaling and metabolic pathways remain unclear. Here we show that hepatocyte-specific loss of the mitochondrial deacetylase SIRT3 drastically impairs regeneration and worsens mitochondrial function after partial hepatectomy. Sirtuins, including SIRT3, require nicotinamide adenine dinucleotide (NAD) as a cosubstrate. We previously showed that the NAD precursor nicotinamide riboside (NR) promotes liver regeneration, but whether this involves sirtuins has not been tested. Here we show that despite their NAD-dependence and critical roles in regeneration, neither SIRT3 nor its nuclear counterpart SIRT1 is required for NR to enhance liver regeneration. NR improves mitochondrial respiration in regenerating wild type or mutant livers and rapidly increases oxygen consumption and glucose output in cultured hepatocytes. Our data support a direct enhancement of mitochondrial redox metabolism as the mechanism mediating improved liver regeneration after NAD supplementation and exclude signaling via SIRT1 and SIRT3. Thus, we provide the first evidence for an essential role for a mitochondrial sirtuin during liver regeneration and insight into the beneficial effects of NR.
Authors
Sarmistha Mukherjee, James Mo, Lauren M. Paolella, Caroline E. Perry, Jade Toth, Mindy M. Hugo, Qingwei Chu, Qiang Tong, Karthikeyani Chellappa, Joseph A. Baur
Abstract
ORM1-like 3 (ORMDL3) has strong genetic linkage to childhood onset asthma. To determine whether ORMDL3 selective expression in airway smooth muscle (ASM) influences ASM function we used cre/lox techniques to generate transgenic mice (hORMDL3Myh11eGFP-cre) which express human ORMDL3 selectively in smooth muscle cells. In vitro studies of ASM cells isolated from the bronchi of hORMDL3Myh11eGFP-cre mice demonstrated that they developed hypertrophy (quantitated by FACS and image analysis), hyperplasia (assessed by BrdU incorporation), and expressed increased levels of tropomysin proteins TPM1 and TPM4. siRNA knockdown of TPM1 or TPM4 demonstrated their importance to ORMDL3 mediated ASM proliferation but not hypertrophy. In addition, ASM derived from hORMDL3Myh11eGFP-cre mice had increased contractility to histamine in vitro which was associated with increased levels of intracellular Ca2+, increased cell surface membrane Orai1 Ca2+ channels which mediate influx of Ca2+ into the cytoplasm, and increased expression of ASM contractile genes Serca2b and Sm22. In vivo studies of hORMDL3Myh11eGFP-cre mice demonstrated that they had a spontaneous increase in ASM and AHR. ORMDL3 expression in ASM thus induces changes in ASM (hypertrophy, hyperplasia, increased contractility) which may explain the contribution of ORMDL3 to the development of AHR in childhood onset asthma which is highly linked to ORMDL3 on chromosome 17q12-21.
Authors
Alexa K. Pham, Marina Miller, Peter Rosenthal, Sudipta Das, Ning Weng, Sunghoon Jang, Richard C. Kurten, Jana Badrani, Taylor A. Doherty, Brian G. Oliver, David H. Broide
Abstract
During denervation induced muscle atrophy, the loss of neuro-muscular junction (NMJ) integrity and the consequent cessation of nerve signal transmission to muscle, lead to a decline in myofiber size mass and contractile activity. However, the identity of the cell types implicated in the muscle response to nerve injury has not been clearly defined. Here, we describe a subpopulation of muscle resident glial cells activated by loss of NMJ integrity. Gene expression analysis at bulk and single cell level revealed the existence of a population of Itga7-expressing cells, which are distinct from muscle satellite cells and are selectively activated upon nerve injury. Upon nerve lesion, these cells expanded and activated a neurotrophic gene program, including the expression of a prospective selection marker – Ngfr – and a number of neurotrophic genes as well as ECM components. Among them, we observed that Tenascin C (Tnc) was specifically produced by muscle glial cells activated by nerve injury and preferentially localized to NMJ. Activation of muscle-resident glial cells by nerve injury induced a neurotrophic phenotype, which was reversible upon recovery of NMJ integrity; by contrast, muscle-resident glial cells in skeletal muscles of a mouse model of Amyotrophic Lateral Sclerosis (ALS) steadily increased over the course of the disease and exhibited an impaired neurotrophic activity, suggesting that pathogenic activation of glial cells may be implicated in ALS progression.
Authors
Daisy Proietti, Lorenzo Giordani, Marco De Bardi, Chiara D'Ercole, Biliana Lozanoska-Ochser, Susanna Amadio, Cinzia Volontè, Sara Marinelli, Antoine Muchir, Marina Bouchè, Giovanna Borsellino, Alessandra Sacco, Pier Lorenzo Puri, Luca Madaro
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