The SARS-CoV-2 novel coronavirus global pandemic (COVID-19) has led to millions of cases and hundreds of thousands of deaths globally. While older adults appear at high risk for severe disease, hospitalizations and deaths due to SARS-CoV-2 among children have been relatively rare. Integrating single-cell RNA sequencing (scRNA-seq) of developing mouse lung with temporally-resolved immunofluorescence in mouse and human lung tissue, we found expression of SARS-CoV-2 Spike protein primer TMPRSS2 was highest in ciliated cells and type I alveolar epithelial cells (AT1), and TMPRSS2 expression increased with aging in mice and humans. Analysis of autopsy tissue from fatal COVID-19 cases detected SARS-CoV-2 RNA most frequently in ciliated and secretory cells in airway epithelium and AT1 cells in peripheral lung. SARS-CoV-2 RNA was highly colocalized in cells expressing TMPRSS2. Together, these data demonstrate the cellular spectrum infected by SARS-CoV-2 in lung epithelium and suggest that developmental regulation of TMPRSS2 may underlie the relative protection of infants and children from severe respiratory illness.
Bryce A. Schuler, A. Christian Habermann, Erin J. Plosa, Chase J. Taylor, Christopher Jetter, Nicholas M. Negretti, Meghan E. Kapp, John T. Benjamin, Peter Gulleman, David S. Nichols, Lior Z. Braunstein, Alice Hackett, Michael Koval, Susan H. Guttentag, Timothy S. Blackwell, Steven A. Webber, Nicholas E. Banovich, Jonathan A. Kropski, Jennifer M. S. Sucre
Diabetes mellitus (DM) is a risk factor for cancer development. However, the role of DM induced hyperglycemic stress (HG) in the development of blood cancer is poorly understood, largely due to lack of appropriate animal models. Epidemiologic studies show that individuals with DM are more likely to possess higher rate of mutations in genes found in pre-leukemic stem and progenitor cells (pre-LHSC/Ps) including in the epigenetic regulator TET2. TET2-mutant pre-LHSC/Ps require additional hits to evolve into a full-blown leukemia and/or aggressive myeloproliferative neoplasm (MPN). Cell intrinsic mutations have been shown to cooperate with Tet2 to promote leukemic transformation. However, the role of extrinsic factors is poorly understood. Utilizing a novel mouse model bearing haploinsufficiency of Tet2, to mimic the human pre-LHSC/P condition and HG stress, in the form of an Ins2Akita/+ mutation, which induces HG and Type-1 DM, we show that the compound mutant mice develop a lethal form of MPN and/or acute myeloid leukemia (AML). RNAseq revealed that this is in part due to upregulation of pro-inflammatory pathways, thereby generating a feedforward loop, including the expression of an anti-apoptotic lncRNA Morrbid. Loss of Morrbid in the compound mutants rescues the lethality and mitigates the development of MPN/AML. Our results describe a novel mouse model for age-dependent AML/MPN and suggest that HG stress acts as an environmental driver for myeloid neoplasm, which could be effectively prevented by reducing the expression of inflammation-related lncRNA Morrbid.
Zhigang Cai, Xiaoyu Lu, Chi Zhang, Sai Nelanuthala, Fabiola Aguilera, Abigail Hadley, Baskar Ramdas, Fang Fang, Kenneth P. Nephew, Jonathan J. Kotzin, Adam Williams, Jorge Henao-Mejia, Laura S. Haneline, Reuben Kapur
A considerable fraction of B cells recognize SARS-CoV-2 with germline-encoded elements of their B cell receptor resulting in the production of neutralizing and non-neutralizing antibodies. We found that antibody sequences from different discovery cohorts shared biochemical properties and could be retrieved across validation cohorts confirming the stereotyped character of this naive response in COVID-19. While neutralizing antibody sequences were found independently of disease severity in line with serological data, individual non-neutralizing antibody sequences were associated with fatal clinical courses suggesting detrimental effects of these antibodies. We mined 200 immune repertoires of healthy individuals and 500 of patients with blood or solid cancers - all acquired prior to the pandemic - for SARS-CoV-2 antibody sequences. While the largely unmutated B cell rearrangements occurred in a substantial fraction of immune repertoires from young and healthy individuals, these sequences were less likely found in individuals over 60 years of age and in cancer. This reflects B cell repertoire restriction in aging and cancer and may to a certain extent explain the different clinical COVID-19 courses observed in these risk groups. Future studies will have to address if this stereotyped B cell response to SARS-CoV-2 emerging from unmutated antibody rearrangements will create long-lived memory.
Lisa Paschold, Donjete Simnica, Edith Willscher, Maria J.G.T. Vehreschild, Jochen Dutzmann, Daniel G. Sedding, Christoph Schultheiß, Mascha Binder
Four different endemic coronaviruses (eCoVs) are etiologic agents for the seasonal “common cold,” and these eCoVs share extensive sequence homology with human severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Here, we show that individuals with as compared to without a relatively recent documented eCoV were tested at greater frequency for respiratory infections but had similar rate of SARS-CoV-2 acquisition. Importantly, the patients with a previously detected eCoV had less severe coronavirus disease-2019 (COVID-19) illness. Our observations suggest that pre-existing immune responses against endemic human coronaviruses can mitigate disease manifestations from SARS-CoV-2 infection.
Manish Sagar, Katherine Reifler, Michael Rossi, Nancy S. Miller, Pranay Sinha, Laura White, Joseph P. Mizgerd
Desmoglein 3 chimeric autoantibody receptor T-cells (DSG3-CAART) expressing the pemphigus vulgaris (PV) autoantigen DSG3, fused to CD137-CD3ζ signaling domains, represent a precision cellular immunotherapy approach for antigen-specific B-cell depletion. Here, we present definitive preclinical studies enabling a first-in-human trial of DSG3-CAART for mucosal PV. DSG3-CAART specifically lysed human anti-DSG3 B-cells from PV patients and demonstrated activity consistent with a threshold dose in vivo, resulting in decreased target cell burden, decreased serum and tissue-bound autoantibodies, and increased DSG3-CAART engraftment. In a PV active immune model with physiologic anti-DSG3 IgG levels, DSG3-CAART inhibited antibody responses against pathogenic DSG3 epitopes and autoantibody binding to epithelial tissues, leading to clinical and histologic resolution of blisters. DSG3 autoantibodies stimulate DSG3-CAART IFNγ secretion and homotypic clustering, consistent with an activated phenotype. Toxicology screens using primary human cells and high-throughput membrane proteome arrays did not identify off-target cytotoxic interactions. These preclinical data guided the trial design for DSG3-CAART and may help inform CAART preclinical development for other antibody-mediated diseases.
Jinmin Lee, Daniel K. Lundgren, Xuming Mao, Silvio Manfredo-Vieira, Selene Nunez-Cruz, Erik F. Williams, Charles-Antoine Assenmacher, Enrico Radaelli, Sangwook Oh, Baomei Wang, Christoph T. Ellebrecht, Joseph A. Fraietta, Michael C. Miloneǂ, Aimee S. Payne
Particulate matter < 2.5 micrometers (PM2.5) air pollution is the world’s leading environmental risk factor contributing to mortality through cardiometabolic pathways. In this study, we modeled early life exposure using chow-fed C57BL/6J male mice, exposed to real-world inhaled concentrated PM2.5 (~10 times ambient levels / ~60-120ug/m3) or filtered air over 14 weeks. We investigated PM2.5 effects on phenotype, transcriptome and chromatin accessibility, compared the effects with a prototypical high-fat diet (HFD) stimulus, and examined cessation of exposure on reversibility of phenotype. Exposure to PM2.5 impaired glucose and insulin tolerance, reduced energy expenditure and 18FDG-PET uptake in brown adipose tissue. Multiple differentially expressed gene (DEG) clusters in pathways involving metabolism and circadian rhythm were noted in insulin responsive tissues. Although the magnitude of transcriptional change seen with PM2.5 was lower than HFD, the degree of alteration in chromatin accessibility after PM2.5 exposure was significant. A novel chromatin remodeler SMARCA5 (SWI/SNF complex) was regulated in response to PM2.5 with cessation of exposure associated with reversal of insulin resistance, restoration of chromatin accessibility/nucleosome positioning near transcription start sites (TSS) and exposure induced changes in the transcriptome including SMARCA5, indicating pliable epigenetic control mechanisms following exposure cessation.
Sanjay Rajagopalan, Bongsoo Park, Rengasamy Palanivel, Vinesh Vinayachandran, Jeffrey A. Deiuliis, Roopesh Singh Gangwar, Lopa M. Das, Jinhu Yin, Youngshim Choi, Sadeer Al-Kindi, Mukesh K. Jain, Kasper D. Hansen, Shyam Biswal
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.
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
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.
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
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.
Jinhui Dong, Iuliia Gilchuk, Sheng Li, Ryan Irving, Matthew T. Goff, Hannah L. Turner, Andrew B. Ward, Robert H. Carnahan, James E. Crowe Jr.
Peripheral neurotoxicity is a debilitating toxicity 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 to 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 preventative 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.
Kevin M. Huang, Alix F. Leblanc, Muhammad Erfan Uddin, Ji Young Kim, Mingqing Chen, Eric D. Eisenmann, Alice Gibson, Yang Li, Kristen W. Hong, Duncan DiGiacomo, Sherry Huinan Xia, Paola Alberti, Alessia Chiorazzi, Stephen N. Housley, Timothy C. Cope, Jason A. Sprowl, Jing Wang, Charles L. Loprinzi, Anne Noonan, Maryam Lustberg, Guido Cavaletti, Navjotsingh Pabla, Shuiying Hu, Alex Sparreboom
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