Cifuentes Kottkamp A, De Jesus E, Grande R, Brown JA, Jacobs AR, Lim JK and Stapleford KA
PMID: 30894466 | DOI: 10.1128/jvi.00389-19
Arthropod-borne viruses represent a significant public health threat worldwide yet there are few antiviral therapies or prophylaxis targeting these pathogens. In particular, the development of novel antivirals for high-risk populations such as pregnant women is essential to prevent devastating disease such as that which was experienced with the recent outbreak of Zika virus (ZIKV) in the Americas. One potential avenue to identify new and pregnancy-acceptable antiviral compounds is to repurpose well-known and widely used FDA approved drugs. In this study, we addressed the antiviral role of atovaquone, a FDA Pregnancy Category C drug and pyrimidine biosynthesis inhibitor used for the prevention and treatment of parasitic infections. We found that atovaquone was able to inhibit ZIKV and chikungunya virus virion production in human cells and that this antiviral effect occurred early during infection at the initial steps of viral RNA replication. Moreover, we were able to complement viral replication and virion production with the addition of exogenous pyrimidine nucleosides indicating that atovaquone is functioning through the inhibition of the pyrimidine biosynthesis pathway to inhibit viral replication. Finally, using an ex vivo human placental tissue model, we found that atovaquone could limit ZIKV infection in a dose-dependent manner providing evidence that atovaquone may function as an antiviral in humans. Taken together, these studies suggest that atovaquone could be a broad-spectrum antiviral drug and a potential attractive candidate for the prophylaxis or treatment of arbovirus infection in vulnerable populations, such as pregnant women and children.IMPORTANCE The ability to protect vulnerable populations such as pregnant women and children from Zika virus and other arbovirus infections is essential to preventing the devastating complications induced by these viruses. One class of antiviral therapies may lie in known pregnancy-acceptable drugs that have the potential to mitigate arbovirus infections and disease yet this has not been explored in detail. In this study, we show that the common antiparasitic drug, atovaquone, inhibits arbovirus replication through intracellular nucleotide depletion and can impair ZIKV infection in an ex vivo human placental explant model. Our study provides a novel function for atovaquone and highlights that the rediscovery of pregnancy-acceptable drugs with potential antiviral effects can be the key to better addressing the immediate need for treating viral infections and preventing potential birth complications and future disease.
Viral mapping in COVID-19 deceased in the Augsburg autopsy series of the first wave: A multiorgan and multimethodological approach
Hirschbühl, K;Dintner, S;Beer, M;Wylezich, C;Schlegel, J;Delbridge, C;Borcherding, L;Lippert, J;Schiele, S;Müller, G;Moiraki, D;Spring, O;Wittmann, M;Kling, E;Braun, G;Kröncke, T;Claus, R;Märkl, B;Schaller, T;
PMID: 34280238 | DOI: 10.1371/journal.pone.0254872
COVID-19 is only partly understood, and the level of evidence available in terms of pathophysiology, epidemiology, therapy, and long-term outcome remains limited. During the early phase of the pandemic, it was necessary to effectively investigate all aspects of this new disease. Autopsy can be a valuable procedure to investigate the internal organs with special techniques to obtain information on the disease, especially the distribution and type of organ involvement.During the first wave of COVID-19 in Germany, autopsies of 19 deceased patients were performed. Besides gross examination, the organs were analyzed with standard histology and polymerase-chain-reaction for SARS-CoV-2. Polymerase chain reaction positive localizations were further analyzed with immunohistochemistry and RNA-in situ hybridization for SARS-CoV-2.Eighteen of 19 patients were found to have died due to COVID-19. Clinically relevant histological changes were only observed in the lungs. Diffuse alveolar damage in considerably different degrees was noted in 18 cases. Other organs, including the central nervous system, did not show specific micromorphological alterations. In terms of SARS-CoV-2 detection, the focus remains on the upper airways and lungs. This is true for both the number of positive samples and the viral load. A highly significant inverse correlation between the stage of diffuse alveolar damage and viral load was found on a case and a sample basis. Mediastinal lymph nodes and fat were also affected by the virus at high frequencies. By contrast, other organs rarely exhibited a viral infection. Moderate to strong correlations between the methods for detecting SARS-CoV-2 were observed for the lungs and for other organs.The lung is the most affected organ in gross examination, histology and polymerase chain reaction. SARS-CoV-2 detection in other organs did not reveal relevant or specific histological changes. Moreover, we did not find CNS involvement.
Zhou, J;Guan, MY;Li, RT;Qi, YN;Yang, G;Deng, YQ;Li, XF;Li, L;Yang, X;Liu, JF;Qin, CF;
PMID: 36739631 | DOI: 10.1016/j.ebiom.2023.104457
Zika virus (ZIKV) is an emerging arbovirus of the genus flavivirus that is associated with congenital Zika syndrome (CZS) in newborns. A wide range of clinical symptoms including intellectual disability, speech delay, coordination or movement problems, and hearing and vision loss, have been well documented in children with CZS. However, whether ZIKV can invade the olfactory system and lead to post-viral olfactory dysfunction (PVOD) remains unknown.We investigated the susceptibility and biological responses of the olfactory system to ZIKV infection using mouse models and human olfactory organoids derived from patient olfactory mucosa.We demonstrate that neonatal mice infected with ZIKV suffer from transient olfactory dysfunction when they reach to puberty. Moreover, ZIKV mainly targets olfactory ensheathing cells (OECs) and exhibits broad cellular tropism colocalizing with small populations of mature/immature olfactory sensory neurons (mOSNs/iOSNs), sustentacular cells and horizontal basal cells in the olfactory mucosa (OM) of immunodeficient AG6 mice. ZIKV infection induces strong antiviral immune responses in both the olfactory mucosa and olfactory bulb tissues, resulting in the upregulation of proinflammatory cytokines/chemokines and genes related to the antiviral response. Histopathology and transcriptomic analysis showed typical tissue damage in the olfactory system. Finally, by using an air-liquid culture system, we showed that ZIKV mainly targets sustentacular cells and OECs and support robust ZIKV replication.Our results demonstrate that olfactory system represents as significant target for ZIKV infection, and that PVOD may be neglected in CZS patients.Stated in the acknowledgment.
Successful hemostasis of bleeding gastric inflammatory fibroid polyp by endoscopic treatment in a patient with severe COVID-19
Clinical journal of gastroenterology
Murota, A;Yoshi, S;Okuda, R;Oowada, S;Yamakawa, T;Kazama, T;Hirayama, D;Ishigami, K;Yamano, HO;Narimatu, E;Sugita, S;Hasegawa, T;Nakase, H;
PMID: 33840076 | DOI: 10.1007/s12328-021-01402-w
The coronavirus disease-2019 (COVID-19) has rapidly become a pandemic, resulting in a global suspension of non-emergency medical procedures such as screening endoscopic examinations. There have been several reports of COVID-19 patients presenting with gastrointestinal symptoms such as diarrhea and vomiting. In this report, we present a case of successful hemostasis of bleeding gastric inflammatory fibroid polyp by endoscopic treatment in a patient with severe COVID-19. The case was under mechanical ventilation with extracorporeal membrane oxygenation (ECMO), and the airway was on a closed circuit. This indicates that COVID-19 is associated with not only lung injury but also intestinal damage, and that proper protective protocols are essential in guaranteeing the best outcomes for patients and clinical professionals during this pandemic.
Bhatnagar J, Rabeneck DB, Martines RB, Reagan-Steiner S, Ermias Y, Estetter LB, Suzuki T, Ritter J, Keating MK, Hale G, Gary J, Muehlenbachs A, Lambert A, Lanciotti R, Oduyebo T, Meaney-Delman D, Bolaños F, Saad EA, Shieh WJ, Zaki SR.
PMID: 27959260 | DOI: 10.3201/eid2303.161499
Zika virus is causally linked with congenital microcephaly and may be associated with pregnancy loss. However, the mechanisms of Zika virus intrauterine transmission and replication and its tropism and persistence in tissues are poorly understood. We tested tissues from 52 case-patients: 8 infants with microcephaly who died and 44 women suspected of being infected with Zika virus during pregnancy. By reverse transcription PCR, tissues from 32 (62%) case-patients (brains from 8 infants with microcephaly and placental/fetal tissues from 24 women) were positive for Zika virus. In situ hybridization localized replicative Zika virus RNA in brains of 7 infants and in placentas of 9 women who had pregnancy losses during the first or second trimester. These findings demonstrate that Zika virus replicates and persists in fetal brains and placentas, providing direct evidence of its association with microcephaly. Tissue-based reverse transcription PCR extends the time frame of Zika virus detection in congenital and pregnancy-associated infections.
Jagger BW, Miner JJ, Cao B, Arora N, Smith AM, Kovacs A, Mysorekar IU, Coyne CB, Diamond MS.
PMID: 28910635 | DOI: 10.1016/j.chom.2017.08.012
Although Zika virus (ZIKV)-induced congenital disease occurs more frequently during early stages of pregnancy, its basis remains undefined. Using established type I interferon (IFN)-deficient mouse models of ZIKV transmission in utero, we found that the placenta and fetus were more susceptible to ZIKV infection at earlier gestational stages. Whereas ZIKV infection at embryonic day 6 (E6) resulted in placental insufficiency and fetal demise, infections at midstage (E9) resulted in reduced cranial dimensions, and infection later in pregnancy (E12) caused no apparent fetal disease. In addition, we found that fetuses lacking type III IFN-λ signaling had increased ZIKV replication in the placenta and fetus when infected at E12, and reciprocally, treatment of pregnant mice with IFN-λ2 reduced ZIKV infection. IFN-λ treatment analogously diminished ZIKV infection in human midgestation fetal- and maternal-derived tissue explants. Our data establish a model of gestational stage dependence of ZIKV pathogenesis and IFN-λ-mediated immunity at the maternal-fetal interface.
Yu, P;Deng, W;Bao, L;Qu, Y;Xu, Y;Zhao, W;Han, Y;Qin, C;
PMID: 35094625 | DOI: 10.1177/03009858211071016
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes severe viral pneumonia and is associated with a high fatality rate. A substantial proportion of patients infected by SARS-CoV-2 suffer from mild hyposmia to complete loss of olfactory function, resulting in anosmia. However, the pathogenesis of the olfactory dysfunction and comparative pathology of upper respiratory infections with SARS-CoV-2 are unknown. We describe the histopathological, immunohistochemical, and in situ hybridization findings from rodent models of SARS-CoV-2 infection. The main histopathological findings in the olfactory epithelia of K8-hACE2 Tg mice, hACE2 Tg mice, and hamsters were varying degrees of inflammatory lesions, including disordered arrangement, necrosis, exfoliation, and macrophage infiltration of the olfactory epithelia, and inflammatory exudation. On the basis of these observations, the nasal epithelia of these rodent models appeared to develop moderate, mild, and severe rhinitis, respectively. Correspondingly, SARS-CoV-2 viral RNA and antigen were mainly identified in the olfactory epithelia and lamina propria. Moreover, viral RNA was abundant in the cerebrum of K18-hACE2 Tg mice, including the olfactory bulb. The K8-hACE2 Tg mouse, hACE2 Tg mouse, and hamster models could be used to investigate the pathology of SARS-CoV-2 infection in the upper respiratory tract and central nervous system. These models could help to provide a better understanding of the pathogenic process of this virus and to develop effective medications and prophylactic treatments.
Griffin, B;Warner, B;Chan, M;Valcourt, E;Tailor, N;Banadyga, L;Leung, A;He, S;Boese, A;Audet, J;Cao, W;Moffat, E;Garnett, L;Tierney, K;Tran, K;Albietz, A;Manguiat, K;Soule, G;Bello, A;Vendramelli, R;Lin, J;Deschambault, Y;Zhu, W;Wood, H;Mubareka, S;Safronetz, D;Strong, J;Embury-Hyatt, C;Kobasa, D;
| DOI: 10.1016/j.isci.2021.103530
The golden hamster model of SARS-CoV-2 infection recapitulates key characteristics of COVID-19. In this work we examined the influence of the route of exposure, sex, and age on SARS-CoV-2 pathogenesis in hamsters. We report that delivery of SARS-CoV-2 by a low versus high volume intranasal or intragastric route results in comparable viral titers in the lung and viral shedding. However, low-volume intranasal exposure results in milder weight loss while intragastric exposure leads to a diminished capacity to regain body weight. Male hamsters, and particularly older male hamsters, display an impaired capacity to recover from illness and delayed viral clearance. These factors were found to influence the nature of the host inflammatory cytokine response, but had a minimal effect on the quality and durability of the humoral immune response and susceptibility to re-infection. These data further elucidate key factors that impact pre-clinical challenge studies carried out in the hamster model of COVID-19.
A single intranasal or intramuscular immunization with chimpanzee adenovirus vectored SARS-CoV-2 vaccine protects against pneumonia in hamsters
Bricker, T;Darling, T;Hassan, A;Harastani, H;Soung, A;Jiang, X;Dai, Y;Zhao, H;Adams, L;Holtzman, M;Bailey, A;Case, J;Fremont, D;Klein, R;Diamond, M;Boon, A;
| DOI: 10.1016/j.celrep.2021.109400
The development of an effective vaccine against SARS-CoV-2, the etiologic agent of COVID-19, is a global priority. Here, we compared the protective capacity of intranasal and intramuscular delivery of a chimpanzee adenovirus-vectored vaccine encoding a pre-fusion stabilized spike protein (ChAd-SARS-CoV-2-S) in Golden Syrian hamsters. While immunization with ChAd-SARS-CoV-2-S induced robust spike protein specific antibodies capable of neutralizing the virus, antibody levels in serum were higher in hamsters vaccinated by an intranasal compared to intramuscular route. Accordingly, against challenge with SARS-CoV-2, ChAd-SARS-CoV-2-S immunized hamsters were protected against less weight loss and had reduced viral infection in nasal swabs and lungs, and reduced pathology and inflammatory gene expression in the lungs, compared to ChAd-Control immunized hamsters. Intranasal immunization with ChAd-SARS-CoV-2-S provided superior protection against SARS-CoV-2 infection and inflammation in the upper respiratory tract. These findings support intranasal administration of the ChAd-SARS-CoV-2-S candidate vaccine to prevent SARS-CoV-2 infection, disease, and possibly transmission.
Rapid endotheliitis and vascular damage characterize SARS-CoV-2 infection in a human lung-on-chip model
Thacker, VV;Sharma, K;Dhar, N;Mancini, GF;Sordet-Dessimoz, J;McKinney, JD;
PMID: 33908688 | DOI: 10.15252/embr.202152744
Severe cases of SARS-CoV-2 infection are characterized by hypercoagulopathies and systemic endotheliitis of the lung microvasculature. The dynamics of vascular damage, and whether it is a direct consequence of endothelial infection or an indirect consequence of an immune cell-mediated cytokine storm remain unknown. Using a vascularized lung-on-chip model, we find that infection of alveolar epithelial cells leads to limited apical release of virions, consistent with reports of monoculture infection. However, viral RNA and proteins are rapidly detected in underlying endothelial cells, which are themselves refractory to apical infection in monocultures. Although endothelial infection is unproductive, it leads to the formation of cell clusters with low CD31 expression, a progressive loss of barrier integrity and a pro-coagulatory microenvironment. Viral RNA persists in individual cells generating an inflammatory response, which is transient in epithelial cells but persistent in endothelial cells and typified by IL-6 secretion even in the absence of immune cells. Inhibition of IL-6 signalling with tocilizumab reduces but does not prevent loss of barrier integrity. SARS-CoV-2-mediated endothelial cell damage thus occurs independently of cytokine storm.
Richner JM, Jagger BW, Shan C, Fontes CR, Dowd KA, Cao B, Himansu S, Caine EA, Nunes BTD, Medeiros DBA, Muruato AE, Foreman BM, Luo H, Wang T, Barrett AD, Weaver SC, Vasconcelos PFC, Rossi SL, Ciaramella G, Mysorekar IU, Pierson TC, Shi PY, Diamond MS.
PMID: 28708997 | DOI: 10.1016/j.cell.2017.06.040
The emergence of Zika virus (ZIKV) and its association with congenital malformations has prompted the rapid development of vaccines. Although efficacy with multiple viral vaccine platforms has been established in animals, no study has addressed protection during pregnancy. We tested in mice two vaccine platforms, a lipid nanoparticle-encapsulated modified mRNA vaccine encoding ZIKV prM and E genes and a live-attenuated ZIKV strain encoding an NS1 protein without glycosylation, for their ability to protect against transmission to the fetus. Vaccinated dams challenged with a heterologous ZIKV strain at embryo day 6 (E6) and evaluated at E13 showed markedly diminished levels of viral RNA in maternal, placental, and fetal tissues, which resulted in protection against placental damage and fetal demise. As modified mRNA and live-attenuated vaccine platforms can restrict in utero transmission of ZIKV in mice, their further development in humans to prevent congenital ZIKV syndrome is warranted.
Gorman MJ, Caine EA, Zaitsev K, Begley MC, Weger-Lucarelli J, Uccellini MB, Tripathi S, Morrison J, Yount BL, Dinnon KH 3rd, Rückert C, Young MC, Zhu Z, Robertson SJ, McNally KL, Ye J, Cao B, Mysorekar IU, Ebel GD, Baric RS, Best SM, Artyomov MN, Garcia-S
PMID: 29746837 | DOI: 10.1016/j.chom.2018.04.003
Progress toward understanding Zika virus (ZIKV) pathogenesis is hindered by lack of immunocompetent small animal models, in part because ZIKV fails to effectively antagonize Stat2-dependent interferon (IFN) responses in mice. To address this limitation, we first passaged an African ZIKV strain (ZIKV-Dak-41525) through Rag1-/- mice to obtain a mouse-adapted virus (ZIKV-Dak-MA) that was more virulent than ZIKV-Dak-41525 in mice treated with an anti-Ifnar1 antibody. A G18R substitution in NS4B was the genetic basis for the increased replication, and resulted in decreased IFN-β production, diminished IFN-stimulated gene expression, and the greater brain infection observed with ZIKV-Dak-MA. To generate a fully immunocompetent mouse model of ZIKV infection, human STAT2 was introduced into the mouse Stat2 locus (hSTAT2 KI). Subcutaneous inoculation of pregnant hSTAT2 KI mice with ZIKV-Dak-MA resulted in spread to the placenta and fetal brain. An immunocompetent mouse model of ZIKV infection may prove valuable for evaluating countermeasures to limit disease.
