Project description:UnlabelledA rapid expansion of HFMD with enterovirus 71 infection outbreaks has occurred and caused deaths in recent years in China, but no vaccine or antiviral drug is currently available for EV71 infection. This study aims to provide treatment programs for HFMD patients. We conducted a randomized, double-blind, controlled trial and evaluated clinical efficacy of therapy with rHuIFN-α1b in HFMD patients with EV71 infection. There were statistical differences in outcomes including the fever clearance time, healing time of typical skin or oral mucosa lesions, and EV71 viral load of the HFMD patients among ultrasonic aerosol inhalation group, intramuscular injection group and control group. rHuIFN-α1b therapy reduced the fever clearance time, healing time of typical skin or oral mucosa lesions, and EV71 viral load in children with HFMD.Trial registrationChinese Clinical Trial Registry ChiCTR-TRC-14005153.
Project description:Since the SARS-CoV-2 pandemic started in late 2019, the search for protective vaccines and for drug treatments has become mandatory to fight the global health emergency. Travel restrictions, social distancing, and face masks are suitable counter measures, but may not bring the pandemic under control because people will inadvertently or at a certain degree of restriction severity or duration become incompliant with the regulations. Even if vaccines are approved, the need for antiviral agents against SARS-CoV-2 will persist. However, unequivocal evidence for efficacy against SARS-CoV-2 has not been demonstrated for any of the repurposed antiviral drugs so far. Amantadine was approved as an antiviral drug against influenza A, and antiviral activity against SARS-CoV-2 has been reasoned by analogy but without data. We tested the efficacy of amantadine in vitro in Vero E6 cells infected with SARS-CoV-2. Indeed, amantadine inhibited SARS-CoV-2 replication in two separate experiments with IC50 concentrations between 83 and 119 µM. Although these IC50 concentrations are above therapeutic amantadine levels after systemic administration, topical administration by inhalation or intranasal instillation may result in sufficient amantadine concentration in the airway epithelium without high systemic exposure. However, further studies in other models are needed to prove this hypothesis.
Project description:The emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) is of global concern: the virus has caused severe respiratory illness, with 111 confirmed cases and 52 deaths at the time of this article's publication. Therapeutic interventions have not been evaluated in vivo; thus, patient management relies exclusively on supportive care, which, given the high case-fatality rate, is not highly effective. The rhesus macaque is the only known model organism for MERS-CoV infection, developing an acute localized to widespread pneumonia with transient clinical disease that recapitulates mild to moderate human MERS-CoV cases. The combination of interferon-α2b and ribavirin was effective in reducing MERS-CoV replication in vitro; therefore, we initiated this treatment 8 h after inoculation of rhesus macaques. In contrast to untreated, infected macaques, treated animals did not develop breathing abnormalities and showed no or very mild radiographic evidence of pneumonia. Moreover, treated animals showed lower levels of systemic (serum) and local (lung) proinflammatory markers, in addition to fewer viral genome copies, distinct gene expression and less severe histopathological changes in the lungs. Taken together, these data suggest that treatment of MERS-CoV infected rhesus macaques with IFN-α2b and ribavirin reduces virus replication, moderates the host response and improves clinical outcome. As these two drugs are already used in combination in the clinic for other infections, IFN-α2b and ribavirin should be considered for the management of MERS-CoV cases.
Project description:SARS-CoV-2 infection of host cells is driven by binding of the SARS-CoV-2 spike-(S)-protein to lung type II pneumocytes, followed by virus replication. Surfactant protein SP-D, member of the front-line immune defense of the lungs, binds glycosylated structures on invading pathogens such as viruses to induce their clearance from the lungs. The objective of this study is to measure the pulmonary SP-D levels in COVID-19 patients and demonstrate the activity of SP-D against SARS-CoV-2, opening the possibility of using SP-D as potential therapy for COVID-19 patients. Pulmonary SP-D concentrations were measured in bronchoalveolar lavage samples from patients with corona virus disease 2019 (COVID-19) by anti-SP-D ELISA. Binding assays were performed by ELISAs. Protein bridge and aggregation assays were performed by gel electrophoresis followed by silver staining and band densitometry. Viral replication was evaluated in vitro using epithelial Caco-2 cells. Results indicate that COVID-19 patients (n = 12) show decreased pulmonary levels of SP-D (median = 68.9 ng/mL) when compared to levels reported for healthy controls in literature. Binding assays demonstrate that SP-D binds the SARS-CoV-2 glycosylated spike-(S)-protein of different emerging clinical variants. Binding induces the formation of protein bridges, the critical step of viral aggregation to facilitate its clearance. SP-D inhibits SARS-CoV-2 replication in Caco-2 cells (EC90 = 3.7 μg/mL). Therefore, SP-D recognizes and binds to the spike-(S)-protein of SARS-CoV-2 in vitro, initiates the aggregation, and inhibits viral replication in cells. Combined with the low levels of SP-D observed in COVID-19 patients, these results suggest that SP-D is important in the immune response to SARS-CoV-2 and that rhSP-D supplementation has the potential to be a novel class of anti-viral that will target SARS-CoV-2 infection.
Project description:Prion diseases are associated with the conformational conversion of the cellular prion protein (PrP(C)) into the pathological scrapie isoform (PrP(Sc)) in the brain. Both the in vivo and in vitro conversion of PrP(C) into PrP(Sc) is significantly inhibited by differences in amino acid sequence between the two molecules. Using protein misfolding cyclic amplification (PMCA), we now report that the recombinant full-length human PrP (rHuPrP23-231) (that is unglycosylated and lacks the glycophosphatidylinositol anchor) is a strong inhibitor of human prion propagation. Furthermore, rHuPrP23-231 also inhibits mouse prion propagation in a scrapie-infected mouse cell line. Notably, it binds to PrP(Sc), but not PrP(C), suggesting that the inhibitory effect of recombinant PrP results from blocking the interaction of brain PrP(C) with PrP(Sc). Our findings suggest a new avenue for treating prion diseases, in which a patient's own unglycosylated and anchorless PrP is used to inhibit PrP(Sc) propagation without inducing immune response side effects.
Project description:To investigate the virological properties of a SARS-CoV-2 variant, Omicron BA.2, we generated chimeric recombinant viruses that express GFP and encodes the S gene of B.1.1 (ancestral D614G-bearing virus), Delta, BA.1 and BA.2. To verify the genome sequence of the working viruses, we performed viral RNA-sequencing of the viral stock.
Project description:Effective vaccines are slowing the COVID-19 pandemic, but SARS-CoV-2 will likely remain an issue in the future making it important to have therapeutics to treat patients. There are few options for treating patients with COVID-19. We show probenecid potently blocks SARS-CoV-2 replication in mammalian cells and virus replication in a hamster model. Furthermore, we demonstrate that plasma concentrations up to 50-fold higher than the protein binding adjusted IC90 value are achievable for 24 h following a single oral dose. These data support the potential clinical utility of probenecid to control SARS-CoV-2 infection in humans.
Project description:Outbreaks from zoonotic sources represent a threat to both human disease as well as the global economy. Despite a wealth of metagenomics studies, methods to leverage these datasets to identify future threats are underdeveloped. In this study, we describe an approach that combines existing metagenomics data with reverse genetics to engineer reagents to evaluate emergence and pathogenic potential of circulating zoonotic viruses. Focusing on the severe acute respiratory syndrome (SARS)-like viruses, the results indicate that the WIV1-coronavirus (CoV) cluster has the ability to directly infect and may undergo limited transmission in human populations. However, in vivo attenuation suggests additional adaptation is required for epidemic disease. Importantly, available SARS monoclonal antibodies offered success in limiting viral infection absent from available vaccine approaches. Together, the data highlight the utility of a platform to identify and prioritize prepandemic strains harbored in animal reservoirs and document the threat posed by WIV1-CoV for emergence in human populations.
Project description:Interferon-induced transmembrane protein 3 (IFITM3) is an antiviral protein that alters cell membranes to block fusion of viruses. Conflicting reports identified opposing effects of IFITM3 on SARS-CoV-2 infection of cells, and its impact on viral pathogenesis in vivo remains unclear. Here, we show that IFITM3 knockout (KO) mice infected with SARS-CoV-2 experience extreme weight loss and lethality compared to wild-type (WT) mice. KO mice have higher lung viral titers and increases in inflammatory cytokine levels, immune cell infiltration, and histopathology. Mechanistically, we observe disseminated viral antigen staining throughout the lung and pulmonary vasculature in KO mice, as well as increased heart infection, indicating that IFITM3 constrains dissemination of SARS-CoV-2. Global transcriptomic analysis of infected lungs shows upregulation of gene signatures associated with interferons, inflammation, and angiogenesis in KO versus WT animals, highlighting changes in lung gene expression programs that precede severe lung pathology and fatality. Our results establish IFITM3 KO mice as a new animal model for studying severe SARS-CoV-2 infection and overall demonstrate that IFITM3 is protective in SARS-CoV-2 infections in vivo.