Project description:Here, we report the coding-complete genome sequences of 40 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains of the newly emerged recombinant Omicron variants XBB, XBB.1, and XBB.2. The strains were isolated from nasopharyngeal swab samples that had been collected from symptomatic patients in Bangladesh between September and October 2022 and were sequenced using an Oxford Nanopore Technologies (ONT) system.
Project description:Mucosal immunity plays a pivotal role in providing comprehensive protection against upper-airway infections and effectively limiting the shedding and transmission of SARS-CoV-2. Despite its critical importance, there remains a notable absence of nasal spray vaccines endorsed for global use by the World Health Organization. This could be due to the inability of current intranasal vaccines to induce strong mucosal and systemic responses in humans, thus urgently entailing a next-generation of intranasal COVID-19 vaccines with novel and safe technologies. In this study, we prepared a two-component intranasal vaccine that combines adenovirus vectors with a self-assembled subunit protein. Specifically, the adenovirus vector expresses the spike protein of XBB.1.5 variant (Ad5XBB.1.5), and were mixed with the recombinant protein that developed derived from the receptor binding domain (RBD) of XBB.1.5 (RBDXBB.1.5-HR). Combination of Ad5XBB.1.5 and RBDXBB.1.5-HR elicited superior humoral and cellular immunity against XBB.1.5-included variants compared with the individual components. Importantly, the STING signaling pathway was found to be crucial for the adjuvant effect of the adenovirus vector. In addition, to increase the broad-spectrum neutralizing capacities, a trimeric protein derived from the BA.5 variant (RBDBA.5-HR) was incorporated to formulate a three-component vaccine (Ad5XBB.1.5+RBDXBB.1.5-HR+RBDBA.5-HR), indicating the utilization of a combination of an adenovirus-vectored and subunit protein vaccines has the potential to serve as a next-generation intranasal vaccine platform. Of note, intranasally delivery of two-component vaccine provided protective immunity against live Omicron XBB.1.16 virus challenge in mice. Furthermore, the combination of adenovirus and subunit protein vaccine demonstrates excellent tolerability and safety in human subjects, and is able to induce enhanced mucosal immunity as well as high levels of sera neutralizing antibody in all participants. These findings underscore its suitability for clinical application in the prevention of SARS-CoV-2 variants encompassing XBB lineages.
Project description:To date five variants of concern (VOC) of SARS-CoV-2 have emerged that show increased immune evasion. While their evolving escape from humoral immune responses has been analyzed in detail, adaptation of SARS-CoV-2 to human innate immune processes like autophagy are less understood. Here we demonstrate that currently predominant mutation T9I in the structural envelope (E) protein conveys increased resistance against autophagy of recent Omicron VOCs (BA.1, BA5 and XBB.5) compared to earlier SARS-CoV-2 variants. Rare omicron isolates that do not carry E T9I are sensitive towards autophagy. Mechanistic analyses revealed that E I9 inhibits autophagic turnover more efficiently than E T9 due to increased recruitment to autophagosomes and enhanced interaction with early autophagosome markers. Using pseudotyping assays we revealed that mutation T9I in E reduces release efficiency, but protects incoming virion from autophagy. In line, introduction of E T9I into recombinant 2020 SARS-CoV-2 increases its resistance against autophagy, but also attenuates replication. Our data thus reveal autophagy as a fundamental driver of SARS-CoV-2 evolution and improved autophagy escape may have contributed to the success of the Omicron variant.
Project description:An intelligent indoor metasurface robotic is empowered on the physical layer by programmable metasurfaces and on the cyber layer by artificial-intelligence tools.
Project description:We announce the coding-complete genomes of four different strains of SARS-CoV-2 Omicron lineages, XBB.1.16, XBB.2.3, FL.4 (alias of XBB.1.9.1.4), and XBB.3. These strains were obtained between October 2022 and May 2023 from nasopharyngeal swabs of four Bangladeshi individuals, while one of them had a travel history. Genomic data were produced by implementing ARTIC Network-based amplicon sequencing using the Oxford Nanopore Technology.
Project description:The spread of COVID-19 continues, expressed by periodic wave-like increases in morbidity and mortality. The reason for the periodic increases in morbidity is the emergence and spread of novel genetic variants of SARS-CoV-2. A decrease in the efficacy of monoclonal antibodies (mAbs) has been reported, especially against Omicron subvariants. There have been reports of a decrease in the efficacy of specific antiviral drugs as a result of mutations in the genes of non-structural proteins. This indicates the urgent need for practical healthcare to constantly monitor pathogen variability and its effect on the efficacy of preventive and therapeutic drugs. As part of this study, we report the results of the continuous monitoring of COVID-19 in Moscow using genetic and virological methods. As a result of this monitoring, we determined the dominant genetic variants and identified the variants that are most widespread, not only in Moscow, but also in other countries. A collection of viruses from more than 500 SARS-CoV-2 isolates has been obtained and characterized. The genetic lines XBB.1.9.1, XBB.1.9.3, XBB.1.5, XBB.1.16, XBB.2.4, BQ.1.1.45, CH.1.1, and CL.1, representing the greatest concern, were identified among the dominant variants. We studied the in vitro efficacy of mAbs Tixagevimab + Cilgavimab (Evusheld), Sotrovimab, Regdanvimab, Casirivimab + Imdevimab (Ronapreve), and Bebtelovimab, as well as the specific antiviral drugs Remdesivir, Molnupiravir, and Nirmatrelvir, against these genetic lines. At the current stage of the COVID-19 pandemic, the use of mAbs developed against early SARS-CoV-2 variants has little prospect. Specific antiviral drugs retain their activity, but further monitoring is needed to assess the risk of their efficacy being reduced and adjust recommendations for their use.
Project description:The COVID-19 pandemic was marked by successive waves of SARS-CoV-2 variants with distinct properties. The Omicron variant that emerged in late 2021 showed a major antigenic shift and rapidly spread worldwide. Since then, Omicron-derived variants have maintained their global dominance, for reasons that remain incompletely understood. We report that the original Omicron variant BA.1 evolved several traits that converged in facilitating viral spread. First, Omicron displayed an early replicative advantage over previous variants when grown in a reconstructed nasal epithelium model based on primary human cells. The increase in Omicron replication was more marked at the 33°C temperature characteristic of human nasal passages, resulting in a physiologically relevant advantage. Omicron also caused a decrease in epithelial integrity, as measured by transepithelial electrical resistance and caspase-3 activation. Furthermore, Omicron caused a more marked loss of motile cilia at 33°C than other variants, suggesting a capacity to impair mucociliary clearance. RNAseq analysis showed that Omicron induced a broad transcriptional downregulation of ciliary genes but only a limited upregulation of host innate defense genes at 33°C. The lower production of type I and type III interferons in epithelia infected by Omicron compared to those infected by the Delta variant, at 33°C as well as 37°C, confirmed the increased capacity of Omicron to evade the innate antiviral response. Thus, Omicron combined replication speed, motile cilia impairment, and limited induction of innate antiviral responses when propagated in reconstructed nasal epithelia at physiological temperature. Omicron has the capacity to propagate efficiently but stealthily in the upper respiratory tract, which likely contributed to the evolutionary success of this SARS-CoV-2 variant.
Project description:To gain a deeper understanding of Omicron waves in the context of vaccination, we performed scRNA-seq together with single-cell V(D)J sequencing using PBMCs from nine Omicron breakthrough infection patients and six vaccinees to identify the possible cellular and molecular response mechanisms after breakthrough infection.
Project description:The Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first identified in November 2021 in South Africa, has initiated the 5th wave of global pandemics. Here, we systemically examined immunological and metabolic characteristics of Omicron variants infection. We found Omicron resisted to neutralizing antibody targeting receptor binding domain (RBD) of wild-type SARS-CoV-2. Omicron could not be neutralized by sera of Corona Virus Disease 2019 (COVID-19) convalescent individuals who were infected with the Delta variant. Through mass spectrometry on MHC-bound peptidomes, we found that the spike protein of the Omicron variants could generate additional CD8+ T cell epitopes, compared with Delta. These epitopes could induce robust CD8+ T cell responses. Moreover, we found booster vaccination increased the cross-memory CD8+ T cell responses against Omicron. Metabolic regulome analysis of Omicron-specific T cell showed a metabolic profile that promoted memory T cell responses. Consistently, a higher fraction of memory CD8+ T cells were found in Omicron stimulated peripheral blood mononuclear cells (PBMCs). In addition, CD147 was also a receptor for the Omicron variants, and CD147 antibody inhibited infection of Omicron. CD147-mediated Omicron infection in a human CD147 transgenic mouse model induced exudative alveolar pneumonia. Taken together, our data suggested that vaccination booster and receptor blocking antibody are two effective strategies against Omicron.