The American journal of pathology
Nida Sen, H;Vannella, KM;Wang, Y;Chung, JY;Kodati, S;Ramelli, SC;Lee, JW;Perez, P;Stein, SR;Grazioli, A;Dickey, JM;Ylaya, K;Singh, M;Yinda, KC;Platt, A;Ramos-Benitez, MJ;Zerbe, C;Munster, VJ;de Wit, E;Warner, BM;Herr, DL;Rabin, J;Saharia, KK;NIH COVID-19 Autopsy Consortium, ;Kleiner, DE;Hewitt, SM;Chan, CC;Chertow, DS;
PMID: 36963628 | DOI: 10.1016/j.ajpath.2023.02.016
Ophthalmic manifestations and tissue tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in association with coronavirus disease 2019 (COVID-19), but the pathology and cellular localization of SARS-CoV-2 are not well characterized. The objective of this study was to evaluate macroscopic and microscopic changes and investigate cellular localization of SARS-CoV-2 across ocular tissues at autopsy. Ocular tissues were obtained from 25 patients with COVID-19 at autopsy. SARS-CoV-2 nucleocapsid gene RNA was previously quantified by droplet digital PCR from one eye. For this current study, contralateral eyes from 21 patients were fixed in formalin and subject to histopathologic examination. From the other four patients, sections of the droplet digital PCR-positive eyes were evaluated by in situ hybridization to determine the cellular localization of SARS-CoV-2 spike gene RNA. Histopathologic abnormalities, including cytoid bodies, vascular changes, and retinal edema, with minimal or no inflammation in ocular tissues were observed in all 21 cases evaluated. In situ hybridization localized SARS-CoV-2 RNA to neuronal cells of the retinal inner and outer layers, ganglion cells, corneal epithelia, scleral fibroblasts, and oligodendrocytes of the optic nerve. In conclusion, within ocular tissues, a range of common histopathologic alterations were identified, and SARS-CoV-2 RNA was localized to multiple cell types. Further studies will be required to determine whether the alterations observed were caused by SARS-CoV-2 infection, the host immune response, and/or preexisting comorbidities.
Knott, D;Fell, R;Potter, JA;Yuille, S;Salguero, FJ;Graham, VA;Hewson, R;Howat, D;Dowall, SD;
PMID: 36992434 | DOI: 10.3390/v15030725
The emergence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) and its expansion to a worldwide pandemic resulted in efforts to assess and develop interventions to reduce the disease burden. Despite the introduction of vaccine programmes against SARS-CoV-2, global incidence levels in early 2022 remained high, demonstrating a need for the development of physiologically relevant models, which are essential for the identification of alternative antiviral strategies. The hamster model of SARS-CoV-2 infection has been widely adopted due to similarities with humans in terms of host cell entry mechanism (via ACE2), and aspects of symptomology and virus shedding. We have previously described a natural transmission hamster model that better represents the natural course of infection. In the present study, we have conducted further testing of the model using the first-in-class antiviral Neumifil, which has previously shown promise against SARS-CoV-2 after a direct intranasal challenge. Neumifil is an intranasally delivered carbohydrate-binding module (CBM) which reduces the binding of viruses to their cellular receptor. By targeting the host cell, Neumifil has the potential to provide broad protection against multiple pathogens and variants. This study demonstrates that using a combination of a prophylactic and therapeutic delivery of Neumifil significantly reduces the severity of clinical signs in animals infected via a natural route of transmission and indicates a reduction of viral loads in the upper respiratory tract. Further refinements of the model are required in order to ensure the adequate transmission of the virus. However, our results provide additional data to the evidence base of Neumifil efficacy against respiratory virus infection and demonstrate that the transmission model is a potentially valuable tool for testing antiviral compounds against SARS-CoV-2.
Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
Santos, A;Sauer, M;Neil, AJ;Solomon, IH;Hornick, JL;Roberts, DJ;Quade, BJ;Parra-Herran, C;
PMID: 35361888 | DOI: 10.1038/s41379-022-01061-3
Current public health initiatives to contain the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) global pandemic focus on expanding vaccination efforts to include vulnerable populations such as pregnant people. Vaccines using messenger ribonucleic acid (mRNA) technology rely on translation by immune cells, primarily at the injection site. Hesitancy remains among the general population regarding the safety of mRNA vaccines during gestation, and it remains unknown whether the SARS-CoV-2 Spike protein (the product of mRNA vaccines available) accumulates in the placenta after vaccination. Objective: To determine whether Spike protein translation and accumulation occurs in placental tissue in the context of recent mRNA SARC-CoV-2 vaccination during pregnancy. We identified 48 patients receiving one or two doses of mRNA SARS-CoV-2 vaccine during gestation and used immunohistochemistry against SARS-CoV-2 Spike protein in formalin-fixed, paraffin-embedded placental tissue. One placenta, positive for SARS-CoV-2 RNA by in situ hybridization (ISH) was used as positive control. Seven term placentas collected prior to the emergence of SARS-CoV-2 served as negative controls. Eighty one percent of patients in the study group underwent third-trimester delivery; remaining had a first-trimester spontaneous abortion or elective second-trimester termination. Patients received two (52%) or one (48%) vaccine doses during pregnancy, with a median interval between latest dose and delivery of 13 days (range 2-79 days). Most (63%) cases had their latest dose within 15 days prior to delivery. All the placentas in the study and negative control groups were negative for SARS-CoV-2 immunohistochemistry. Six study cases with short vaccine-delivery intervals (2-7 days) were subjected to SARS-CoV-2 ISH and were negative. Our findings suggest that mRNA vaccines do not reach significant concentrations in the placenta given the absence of definitive SARS-CoV-2 Spike protein accumulation in placental tissue. This observation provides evidence supporting the safety of mRNA vaccines to the placental-fetal unit.
The American journal of pathology
Ball, EE;Weiss, CM;Liu, H;Jackson, K;Keel, MK;Miller, CJ;Van Rompay, KKA;Coffey, LL;Pesavento, PA;
PMID: 36906263 | DOI: 10.1016/j.ajpath.2023.02.013
Clinical evidence of vascular dysfunction and hypercoagulability as well as pulmonary vascular damage and microthrombosis are frequently reported in severe cases of human coronavirus disease 2019 (COVID-19). Syrian golden hamsters recapitulate histopathologic pulmonary vascular lesions reported in patients with COVID-19. Here, special staining techniques and transmission electron microscopy further define vascular pathologies in a Syrian golden hamster model of human COVID-19. The results show that regions of active pulmonary inflammation in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are characterized by ultrastructural evidence of endothelial damage with platelet marginalization and both perivascular and subendothelial macrophage infiltration. SARS-CoV-2 antigen/RNA was not detectable within affected blood vessels. Taken together, these findings suggest that the prominent microscopic vascular lesions in SARS-CoV-2-inoculated hamsters are likely due to endothelial damage followed by platelet and macrophage infiltration.
medRxiv : the preprint server for health sciences
Gonzalez, V;Li, L;Buarpung, S;Prahl, M;Robinson, JF;Gaw, SL;
PMID: 36778281 | DOI: 10.1101/2023.02.01.23285349
Despite universal recommendations for COVID-19 mRNA vaccination in pregnancy, uptake has been lower than desired. There have been limited studies of the direct impact of COVID-19 mRNA vaccine exposure in human placental tissue. Using a primary human villous explant model, we investigated the uptake of two common mRNA vaccines (BNT162b2 Pfizer-BioNTech or mRNA-1273 Moderna), and whether exposure altered villous cytokine responses. Explants derived from second or third trimester chorionic villi were incubated with vaccines at supraphysiologic concentrations and analyzed at two time points. We observed minimal uptake of mRNA vaccines in placental explants by in situ hybridization and quantitative RT-PCR. No specific or global cytokine response was elicited by either of the mRNA vaccines in multiplexed immunoassays. Our results suggest that the human placenta does not readily absorb the COVID-19 mRNA vaccines nor generate a significant inflammatory response after exposure.
Ryan, KA;Bewley, KR;Watson, RJ;Burton, C;Carnell, O;Cavell, BE;Challis, A;Coombes, NS;Davies, ER;Edun-Huges, J;Emery, K;Fell, R;Fotheringham, SA;Gooch, KE;Gowan, K;Handley, A;Harris, DJ;Hesp, R;Hunter, L;Humphreys, R;Johnson, R;Kennard, C;Knott, D;Lister, S;Morley, D;Ngabo, D;Osman, KL;Paterson, J;Penn, EJ;Pullan, ST;Richards, KS;Summers, S;Thomas, SR;Weldon, T;Wiblin, NR;Rayner, EL;Vipond, RT;Hallis, B;Salguero, FJ;Funnell, SGP;Hall, Y;
PMID: 37014911 | DOI: 10.1371/journal.ppat.1011293
The mutation profile of the SARS-CoV-2 Omicron (lineage BA.1) variant posed a concern for naturally acquired and vaccine-induced immunity. We investigated the ability of prior infection with an early SARS-CoV-2 ancestral isolate (Australia/VIC01/2020, VIC01) to protect against disease caused by BA.1. We established that BA.1 infection in naïve Syrian hamsters resulted in a less severe disease than a comparable dose of the ancestral virus, with fewer clinical signs including less weight loss. We present data to show that these clinical observations were almost absent in convalescent hamsters challenged with the same dose of BA.1 50 days after an initial infection with ancestral virus. These data provide evidence that convalescent immunity against ancestral SARS-CoV-2 is protective against BA.1 in the Syrian hamster model of infection. Comparison with published pre-clinical and clinical data supports consistency of the model and its predictive value for the outcome in humans. Further, the ability to detect protection against the less severe disease caused by BA.1 demonstrates continued value of the Syrian hamster model for evaluation of BA.1-specific countermeasures.
Nature biomedical engineering
Wang, Z;Popowski, KD;Zhu, D;de Juan Abad, BL;Wang, X;Liu, M;Lutz, H;De Naeyer, N;DeMarco, CT;Denny, TN;Dinh, PC;Li, Z;Cheng, K;
PMID: 35788687 | DOI: 10.1038/s41551-022-00902-5
The first two mRNA vaccines against infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that were approved by regulators require a cold chain and were designed to elicit systemic immunity via intramuscular injection. Here we report the design and preclinical testing of an inhalable virus-like-particle as a COVID-19 vaccine that, after lyophilisation, is stable at room temperature for over three months. The vaccine consists of a recombinant SARS-CoV-2 receptor-binding domain (RBD) conjugated to lung-derived exosomes which, with respect to liposomes, enhance the retention of the RBD in both the mucus-lined respiratory airway and in lung parenchyma. In mice, the vaccine elicited RBD-specific IgG antibodies, mucosal IgA responses and CD4+ and CD8+ T cells with a Th1-like cytokine expression profile in the animals' lungs, and cleared them of SARS-CoV-2 pseudovirus after a challenge. In hamsters, two doses of the vaccine attenuated severe pneumonia and reduced inflammatory infiltrates after a challenge with live SARS-CoV-2. Inhalable and room-temperature-stable virus-like particles may become promising vaccine candidates.
Expert review of vaccines
Neil, JA;Griffith, M;Godfrey, DI;Purcell, DFJ;Deliyannis, G;Jackson, D;Rockman, S;Subbarao, K;Nolan, T;
PMID: 35652289 | DOI: 10.1080/14760584.2022.2071264
Evaluation of immunogenicity and efficacy in animal models provide critical data in vaccine development. Nonhuman primates (NHPs) have been used extensively in the evaluation of SARS-CoV-2 vaccines.A critical synthesis of SARS-CoV-2 vaccine development with a focus on challenge studies in NHPs is provided. The benefits and drawbacks of the NHP models are discussed. The citations were selected by the authors based on PubMed searches of the literature, summaries from national public health bodies, and press-release information provided by vaccine developers.We identify several aspects of NHP models that limit their usefulness for vaccine-challenge studies and numerous variables that constrain comparisons across vaccine platforms. We propose that studies conducted in NHPs for vaccine development should use a standardized protocol and, where possible, be substituted with smaller animal models. This will ensure continued rapid progression of vaccines to clinical trials without compromising assessments of safety or efficacy.
Pathology - Research and Practice
Schwab, C;Domke, L;Rose, F;Hausser, I;Schirmacher, P;Longerich, T;
| DOI: 10.1016/j.prp.2022.154000
Pulmonary capillary microthrombosis has been proposed as a major pathogenetic factor driving severe COVID-19. Autopsy studies reported endothelialitis but it is under debate if it is caused by SARS-CoV-2 infection of endothelial cells. In this study, RNA in situ hybridization was used to detect viral RNA and to identify the infected cell types in lung tissue of 40 patients with fatal COVID-19. SARS-CoV-2 Spike protein-coding RNA showed a steadily decreasing signal abundance over a period of three weeks. Besides the original virus strain the variants of concern Alpha (B.1.1.7), Delta (B.1.617.2), and Omicron (B.1.1.529) could also be detected by the assay. Viral RNA was mainly detected in alveolar macrophages and pulmonary epithelial cells, while only single virus-positive endothelial cells were observed even in cases with high viral load suggesting that viral infection of endothelial cells is not a key factor for the development of pulmonary capillary microthrombosis.
Cellular & molecular immunology
Wang, Z;Lv, J;Yu, P;Qu, Y;Zhou, Y;Zhou, L;Zhu, Q;Li, S;Song, J;Deng, W;Gao, R;Liu, Y;Liu, J;Tong, WM;Qin, C;Huang, B;
PMID: 34983944 | DOI: 10.1038/s41423-021-00813-6
Exploring the cross-talk between the immune system and advanced biomaterials to treat SARS-CoV-2 infection is a promising strategy. Here, we show that ACE2-overexpressing A549 cell-derived microparticles (AO-MPs) are a potential therapeutic agent against SARS-CoV-2 infection. Intranasally administered AO-MPs dexterously navigate the anatomical and biological features of the lungs to enter the alveoli and are taken up by alveolar macrophages (AMs). Then, AO-MPs increase the endosomal pH but decrease the lysosomal pH in AMs, thus escorting bound SARS-CoV-2 from phago-endosomes to lysosomes for degradation. This pH regulation is attributable to oxidized cholesterol, which is enriched in AO-MPs and translocated to endosomal membranes, thus interfering with proton pumps and impairing endosomal acidification. In addition to promoting viral degradation, AO-MPs also inhibit the proinflammatory phenotype of AMs, leading to increased treatment efficacy in a SARS-CoV-2-infected mouse model without side effects. These findings highlight the potential use of AO-MPs to treat SARS-CoV-2-infected patients and showcase the feasibility of MP therapies for combatting emerging respiratory viruses in the future.
Han, Y;Yuan, K;Wang, Z;Liu, WJ;Lu, ZA;Liu, L;Shi, L;Yan, W;Yuan, JL;Li, JL;Shi, J;Liu, ZC;Wang, GH;Kosten, T;Bao, YP;Lu, L;
PMID: 34593760 | DOI: 10.1038/s41398-021-01629-8
The coronavirus disease 2019 (COVID-19) pandemic has caused large-scale economic and social losses and worldwide deaths. Although most COVID-19 patients have initially complained of respiratory insufficiency, the presence of neuropsychiatric manifestations is also reported frequently, ranging from headache, hyposmia/anosmia, and neuromuscular dysfunction to stroke, seizure, encephalopathy, altered mental status, and psychiatric disorders, both in the acute phase and in the long term. These neuropsychiatric complications have emerged as a potential indicator of worsened clinical outcomes and poor prognosis, thus contributing to mortality in COVID-19 patients. Their etiology remains largely unclear and probably involves multiple neuroinvasive pathways. Here, we summarize recent animal and human studies for neurotrophic properties of severe acute respiratory syndrome coronavirus (SARS-CoV-2) and elucidate potential neuropathogenic mechanisms involved in the viral invasion of the central nervous system as a cause for brain damage and neurological impairments. We then discuss the potential therapeutic strategy for intervening and preventing neuropsychiatric complications associated with SARS-CoV-2 infection. Time-series monitoring of clinical-neurochemical-radiological progress of neuropsychiatric and neuroimmune complications need implementation in individuals exposed to SARS-CoV-2. The development of a screening, intervention, and therapeutic framework to prevent and reduce neuropsychiatric sequela is urgently needed and crucial for the short- and long-term recovery of COVID-19 patients.
LB740 SARS-CoV-2-associated ‘covid toes:’ multiplex immunofluorescent characterization of pathophysiology
Journal of Investigative Dermatology
Moon, J;Costa da Silva, A;Tran, J;Kim, C;Sharma, R;Hinshaw, M;Shields, B;Brooks, E;Cowen, E;Singh, A;Drolet, B;Mays, J;Arkin, L;
| DOI: 10.1016/j.jid.2021.07.093
Coincident with the start of the COVID-19 pandemic, dermatologists worldwide have reported an uncharacteristic increase in pernio or chilblains (aka ‘COVID toes’). However, the lack of systemic illness, low PCR positivity and lack of consistent seroconversion have led some authors to postulate an epiphenomenon. SARS-CoV-2 spike protein has been identified in a limited number of skin biopsies in few publications, yet there remain conflicting reports regarding other SARS-CoV-2 associated proteins, the presence or absence of viral RNA, and a unifying pathophysiology. In cooperation with the COVID Human Genome Effort, our “COVID toes” biobank was established to identify both the genetic and immunologic basis and provide clinically relevant insights into targeted therapeutics. As of March 2021, we have enrolled 96 patients, creating a prospective biorepository with clinical data, saliva, serial blood collection, and skin biopsies. Here we aim to comprehensively investigate the conflicting findings, detail the inflammatory response, and identify the source of interferon signaling with multiplex immunofluorescence (IFA) and the RNAscope fluorescent assay to detect viral mRNA. Median patient age was 17 (range 2 e 72) and 44/96 (46%) were male. Preliminary IFA results demonstrate detection of SARS-CoV-2 components, robust MxA detection and plasmacytoid dendritic cell (pDC) colocalization, identifying PDCs as the likely primary source of IFN-I production and implicates an excessive localized IFN-I response in affected patients.