BACKGROUND. After its introduction as standard-of-care for severe COVID-19, dexamethasone has been administered to a large number of patients globally. Detailed knowledge of its impact on the cellular and humoral immune response to SARS-CoV-2 remains scarce. METHODS. We included immunocompetent individuals with 1) mild COVID-19, 2) severe COVID-19 before introduction of dexamethasone treatment, and 3) severe COVID-19 infection treated with dexamethasone from prospective observational cohort studies at Charité-Universitätsmedizin Berlin, Germany. We analyzed SARS-CoV-2 spike-reactive T cells, spike-specific IgG titers as well as serum neutralizing activity against B.1.1.7, B.1.617.2 in samples ranging from two weeks to six months post infection. We also analyzed BA.2 neutralization in sera after booster immunization. RESULTS. Patients with severe COVID-19 and dexamethasone treatment had lower T cell and antibody responses to SARS-CoV-2 compared to patients without dexamethasone treatment in the early phase of disease, which converged in both groups before six months post infection and also post-immunization. Patients with mild COVID-19 had a comparatively lower T cell and antibody response than patients with severe disease, including a lower response to booster-immunization during convalescence. CONCLUSION. Dexamethasone treatment is associated with short-term reduction of T cell and antibody response in severe COVID-19 when compared to the non-treated group, but this difference evens out six months after infection. We confirm higher cellular and humoral immune responses in patients after severe versus mild COVID-19 infection and the concept of improved hybrid immunity upon immunization. TRIAL REGISTRATION.: n/aFunding: Berlin Institute of Health, German Federal Ministry of Education and German Federal Institute for Drugs and Medical Devices
Charlotte Thibeault, Lara Bardtke, Kanika Vanshylla, Veronica Cristianzano, Kirsten A. Eberhardt, Paula Stubbemann, David Hillus, Pinkus Tober-Lau, Parnika Mukherjee, Friederike Münn, Lena J Lippert, Elisa T. Helbig, Tilman Lingscheid, Fridolin Steinbeis, Mirja Mittermaier, Martin Witzenrath, Thomas Zoller, Florian Klein, Leif E. Sander, Florian Kurth
This study aimed to enhance anti-tumor immune responses to pancreatic cancer via antibody-based blockade of IL-6 and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Mice bearing subcutaneous or orthotopic pancreatic tumors were treated with blocking antibodies to IL 6 and/or CTLA-4. In both tumor models, dual IL-6 and CTLA-4 blockade significantly inhibited tumor growth. Additional investigations revealed that dual therapy induced an overwhelming infiltration of T cells into the tumor as well as changes in CD4+ T cell subsets. Dual blockade therapy elicited CD4+ T cells to secrete increased IFN-γ in vitro. Likewise, in vitro stimulation of pancreatic tumor cells with IFN-γ profoundly increased tumor cell production of CXCR3 specific chemokines, even in the presence of IL-6. In vivo blockade of CXCR3 prevented orthotopic tumor regression in the presence of the combination treatment, demonstrating a dependence on the CXCR3 axis for anti-tumor efficacy. Both CD4+ and CD8+ T cells were required for the anti-tumor activity of this combination therapy, as their in vivo depletion via antibodies impaired outcomes. These data represent the first report of IL-6 and CTLA 4 blockade as a means to regress pancreatic tumors with defined operative mechanisms of efficacy. Given these results, this therapeutic combination has potential for immediate clinical translation.
Michael Brandon Ware, Maggie Phillips, Christopher McQuinn, Mohammad Y. Zaidi, Hannah M. Knochelmann, Emily Greene, Brian S. Robinson, Cameron J. Herting, Thomas A. Mace, Zhengjia Chen, Chao Zhang, Matthew R. Farren, Amanda N. Ruggieri, Jacob S. Bowers, Reena Shakya, Alton Brad Farris, Gregory Young, William E. Carson III, Bassel El-Rayes, Chrystal M. Paulos, Gregory B. Lesinski
Necrotizing enterocolitis (NEC) is a deadly gastrointestinal disease of premature infants that is associated with an exaggerated inflammatory response, dysbiosis of the gut microbiome, decreased epithelial cell proliferation, and gut barrier disruption. We describe an in vitro model of human neonatal small intestinal epithelium (Neonatal-Intestine-on-a-Chip) that mimics key features of intestinal physiology. This model utilizes premature infant intestinal enteroids grown from surgically harvested intestinal tissue and co-cultured with human intestinal microvascular endothelial cells within a microfluidic device. We used our Neonatal-Intestine-on-a-Chip to recapitulate NEC pathophysiology by adding infant-derived microbiota. This model, named NEC-on-a-Chip, recapitulates the predominant features of NEC including significant upregulation of pro-inflammatory cytokines, decreased intestinal epithelial cell markers, reduced epithelial proliferation, and disrupted epithelial barrier integrity. NEC-on-a-Chip provides an improved preclinical model of NEC that facilitates comprehensive analysis of the pathophysiology of NEC using precious clinical samples. This model is an advance towards a personalized medicine approach to test new therapeutics for this devastating disease.
Wyatt E. Lanik, Cliff J. Luke, Lila S. Nolan, Qingqing Gong, Lauren C. Frazer, Jamie M. Rimer, Sarah E. Gale, Raymond Luc, Shay S. Bidani, Carrie A. Sibbald, Angela N. Lewis, Belgacem Mihi, Pranjal Agrawal, Martin Goree, Marlie M. Maestas, Elise Hu, David G. Peters, Misty Good
Multiple randomized, controlled clinical trials have yielded discordant results regarding the efficacy of convalescent plasma in outpatients, with some showing an approximate two-fold reduction in risk and others showing no effect. We quantified binding and neutralizing antibody levels in 492 of the 511 participants from the C3PO trial of a single unit of COVID-19 convalescent plasma (CCP) vs. saline infusion. In a subset of 70 participants, peripheral blood mononuclear cells were obtained to define the evolution of B and T cell responses through day 30. Binding and neutralizing antibody responses were measurably higher one hour post-infusion in recipients of CCP compared to saline plus multivitamin, but levels achieved by the native immune system by day 15 were much higher than seen immediately after CCP administration. Infusion of CCP did not block generation of the host antibody response or skew B or T cell phenotype or maturation. Activated CD4+ and CD8+ T cells were associated with more severe disease outcome. These data show that CCP leads to a measurable boost in anti-SARS-CoV-2 antibodies, but that the boost is modest and may not be sufficient to alter disease course.
John F. McDyer, Mahzad Azimpouran, Valerie L. Durkalski-Mauldin, Robert G. Clevenger, Sharon D. Yeatts, Xutao Deng, William Barsan, Robert Silbergleit, Nahed El Kassar, Iulia Popescu, Dimiter Dimitrov, Wei Li, Emily J. Lyons, Sophia C. Lieber, Mars Stone, Frederick K. Korley, Clifton W. Callaway, Larry J. Dumont, Philip J. Norris
Hypothalamic neurons regulate body homeostasis by sensing and integrating changes in the levels of key hormones and primary nutrients (amino acids, glucose, and lipids). However, the molecular mechanisms that enable hypothalamic neurons to detect primary nutrients remain elusive. Here, we identified L-type amino acid transporter 1 (LAT1) in hypothalamic leptin receptor (LepR)-expressing neurons as being important for systemic energy and bone homeostasis. We observed LAT1-dependent amino acid uptake in the hypothalamus, which was compromised in a mouse model of obesity and diabetes. Mice lacking LAT1 (encoded by Slc7a5) in LepR-expressing neurons exhibited obesity-related phenotypes and higher bone mass. Slc7a5 deficiency caused sympathetic dysfunction and leptin insensitivity in LepR-expressing neurons before obesity onset. Importantly, restoring Slc7a5 expression selectively in LepR-expressing ventromedial hypothalamus neurons rescued energy and bone homeostasis in mice deficient for Slc7a5 in LepR-expressing cells. Mechanistic target of rapamycin complex-1 (mTORC1) was found to be a crucial mediator of LAT1-dependent regulation of energy and bone homeostasis. These results suggest that the LAT1–mTORC1 axis in LepR-expressing neurons controls energy and bone homeostasis by fine-tuning sympathetic outflow, thus providing in vivo evidence of the implications of amino acid sensing by hypothalamic neurons in body homeostasis.
Gyujin Park, Kazuya Fukasawa, Tetsuhiro Horie, Yusuke Masuo, Yuka Inaba, Takanori Tatsuno, Takanori Yamada, Kazuya Tokumura, Sayuki Iwahashi, Takashi Iezaki, Katsuyuki Kaneda, Yukio Kato, Yasuhito Ishigaki, Michihiro Mieda, Tomohiro Tanaka, Kazuma Ogawa, Hiroki Ochi, Shingo Sato, Yun-Bo Shi, Hiroshi Inoue, Hojoon Lee, Eiichi Hinoi
Low capacity to produce reactive oxygen species (ROS) due to mutations in neutrophil cytosolic factor 1 (NCF1/p47phox), a component of NADPH oxidase 2 (NOX2) complex, is strongly associated with systemic lupus erythematosus in both humans and mouse models. Here, we aim to identify the key immune cell type(s) and cellular mechanisms driving lupus pathogenesis under the condition of NCF1-dependent ROS deficiency. Using a set of cell-specific Cre-deleter, the human NCF1-339 variant knock-in, and transgenic mouse strains, we show that low ROS production in plasmacytoid dendritic cells (pDCs) exacerbates both pristane-induced lupus and a newly established Yaa-related spontaneous model by promoting pDC accumulation in multiple organs during lupus development, accompanied by elevated IFNα levels and expression of IFN-stimulated genes. Mechanistic studies reveal that ROS deficiency enhances pDC generation through the AKT/mTOR pathway and CCR2-mediated migration to tissues, which together with hyperactivation of the redox-sensitive STING/IFNα/JAK1/STAT1 cascade further augments type I IFN responses. More importantly, by suppressing these pathways, restoration of NOX2-derived ROS specifically in pDCs protects against lupus. These discoveries explain the causative effect of dysfunctional NCF1 in lupus and demonstrate the protective role of pDC-derived ROS in disease development driven by NCF1-dependent ROS deficiency.
Huqiao Luo, Vilma Urbonaviciute, Amir Ata Saei, Hezheng Lyu, Massimiliano Gaetani, Ákos Végvári, Yanpeng Li, Roman A. Zubarev, Rikard Holmdahl
BACKGROUND. Fibrocytes are bone marrow-derived circulating cells that traffic to the injured lungs and contribute to fibrogenesis. The mTOR inhibitor, sirolimus, inhibits fibrocyte CXCR4 expression, reducing fibrocyte traffic and attenuating lung fibrosis in animal models. We sought to test the hypothesis that short-term treatment with sirolimus reduces the concentration of CXCR4+ circulating fibrocytes in patients with idiopathic pulmonary fibrosis (IPF). METHODS. We conducted a short-term randomised double-blind placebo-controlled crossoverpilot trial to assess the safety and tolerability of sirolimus in IPF. Subjects were randomly assigned to sirolimus or placebo for approximately 6 weeks, and after a 4 week washout, assigned to the alternate treatment. Toxicity, lung function, and the concentration of circulating fibrocytes were measured before and after each treatment. RESULTS. In the 28 study subjects, sirolimus resulted in a statistically significant 35% decline in the concentration of total fibrocytes, 34% decline in CXCR4+ fibrocytes, and 42% decline in fibrocytes expressing ɑ-smooth muscle actin, but no significant change in these populations occurred on placebo. Respiratory adverse events occurred more frequently during treatment with placebo than sirolimus; the incidence of adverse events and drug tolerability did not otherwise differ during therapy with drug and placebo. Lung function was unaffected by either treatment with the exception of a small decline in gas transfer during treatment with placebo. CONCLUSIONS. As compared with placebo, short-term treatment with sirolimus resulted inreduction of circulating fibrocyte concentrations in subjects with IPF with an acceptable safety profile. TRIAL REGISTRATION. clinicaltrials.gov identifier number NCT01462006 FUNDING. NIH R01HL098329 and American Heart Association 18TPA34170486
Diana C. Gomez Manjarres, Dierdre B. Axell-House, Divya C. Patel, John Odackal, Victor Yu, Marie D. Burdick, Borna Mehrad
BACKGROUND. Cellular stressors influence the development of clonal hematopoiesis (CH). We hypothesized that aging, environmental, inflammatory, and genotoxic stresses drive the emergence of CH in patients with severe lung disease undergoing lung transplantation. METHODS. We performed a cross-sectional cohort study of 85 patients with severe lung disease undergoing transplantation to characterize CH prevalence. We evaluated somatic variants using duplex error-corrected sequencing and germline variants using whole exome sequencing. We evaluated CH frequency and burden using chi-square and Poisson regression, associations with clinical and demographic variables using logistic regression, and associations with clinical outcomes using chi-square, logistic, and Cox regression. RESULTS. CH in DNA damage response (DDR) genes TP53, PPM1D, and ATM was observed at high frequency in transplant recipients compared to a control group of older adults [28% vs. 0%, aOR 12.9 (1.7-100.3), p=0.0002]. Age [OR 1.13 (1.03-1.25), p=0.014] and smoking history [OR 4.25 (1.02-17.82), p=0.048] were associated with CH in DDR genes. Germline variants causing predisposition to idiopathic pulmonary fibrosis, including telomere biology disorders and surfactant-related lung disease were identified but not associated with CH. DDR CH was associated with increased cytomegalovirus viremia compared to patients with no CH [OR 7.23 (1.95-26.8), p=0.009]] or non-DDR CH [OR 7.64 (1.77-32.89, p=0.012)], decreased lymphopenia (aHR 0.49 (0.27 – 0.90), p=0.021) and mycophenolate discontinuation [aOR 3.8 (1.3-12.9), p=0.031]. CONCLUSION. In patients with severe lung disease requiring lung transplantation, CH due to somatic variants in PPM1D, TP53 or ATM is highly prevalent and associated with post-transplant outcomes including cytomegalovirus activation and mycophenolate intolerance. FUNDING. NIH/NHLBI K01HL155231 (LKT), R25HL105400 (LKT), Foundation for Barnes-Jewish Hospital (LKT), Evans MDS Center at Washington University (KAO, MJW), ASH Scholar Award (KAO), NIH K12CA167540 (KAO), NIH P01AI116501 (AEG, DK), NIH R01HL094601 (AEG), and NIH P01CA101937 (DCL).
Laneshia K. Tague, Karolyn A. Oetjen, Anirudh Mahadev, Matthew J. Walter, Hephzibah Anthony, Daniel Kreisel, Daniel C. Link, Andrew E. Gelman
The need for new advances in the management/treatment options for ischemic stroke patients requires that upcoming preclinical research uses animals with more human-like brain characteristics. The porcine brain is considered appropriate although the presence of the rete mirabile (RM) prevents direct catheterization of the intracranial arteries to produce focal cerebral ischemia. To develop a reproducible minimally invasive porcine stroke model, a catheter+guide was introduced through the femoral artery until reaching the left RM. Using the pressure cooker technique (PCT), Squid-12 embolization material was deposited to fill, overflow and occlude the left RM, the left internal carotid artery (ICA) and left circle of Willis (CW) wing up to the origins of the middle cerebral arteries’ (MCAs), thus mimicking the occlusion produced in the filament model in rodents. Longitudinal multimodal cerebral MR imaging was conducted to assess the brain damage and cerebral blood supply. The technique we describe here occluded up to the origins of the MCAs in 7 out of 8 swine, inducing early damage 90 min post-occlusion that later evolved to a large cerebral infarction, and producing no mortality during the intervention. This novel minimally invasive ischemic stroke model in swine produced reproducible infarcts and shows translational features common to human stroke.
Carlos Castaño, Marc Melià-Sorolla, Alexia García-Serran, Núria DeGregorio-Rocasolano, Maria Rosa García-Sort, María Hernandez-Pérez, Adrián Valls Carbó, Osvaldo A. Pino, Jordi Grifols, Alba Iruela-Sánchez, Alicia Palomar-García, Josep Puig, Octavi Martí-Sistac, Antoni Davalos, Teresa Gasull
Sosuga virus (SOSV) is a recently discovered paramyxovirus with a single known human case of disease. There has been little laboratory research on SOSV pathogenesis or immunity, and no approved therapeutics or vaccines are available. Here, we report the discovery of human monoclonal antibodies (mAbs) from the circulating memory B cells of the only known human case and survivor of SOSV infection. We isolated six mAbs recognizing the functional attachment protein hemagglutinin-neuraminidase (HN) and 18 mAbs against the fusion (F) protein. The anti-HN mAbs all target the globular head of the HN protein and can be organized into 4 competition-binding groups that exhibit epitope diversity. The anti-F mAbs can be divided into pre- or postfusion conformation-specific categories and further into 8 competition-binding groups. The only antibody in the panel that did not display neutralization activity was the single, postfusion-specific anti-F mAb. Most of the anti-HN mAbs were more potently neutralizing than the anti-F mAbs, with mAbs in one of the HN competition-binding groups possessing ultra-potent (<1 ng/mL) half maximal inhibitory (IC50) virus neutralization values. These findings provide insight into the molecular basis for human antibody recognition of paramyxovirus surface proteins and the mechanisms of SOSV neutralization.
Helen M. Parrington, Nurgun Kose, Erica Armstrong, Laura S. Handal, Summer Diaz, Joseph Reidy, Jinhui Dong, Guillaume B.E. Stewart-Jones, Punya Shrivastava-Ranjan, Shilpi Jain, César G. Albariño, Robert H. Carnahan, James E. Crowe
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