Acute-on-chronic liver failure (ACLF) is characterized by high levels of systemic inflammation and parallel suppression of innate immunity, whereas little is known about adaptive immune immunity in ...ACLF. We therefore aimed to characterize the development of the adaptive immune system during the progression of liver cirrhosis to ACLF. Patients with compensated/stable decompensated liver cirrhosis, acute decompensation of liver cirrhosis, or ACLF were recruited from a prospective cohort study. Comprehensive immunophenotyping was performed using high dimensional flow cytometry. Replication of
(TT) virus was quantified as a marker of immunosuppression. High frequencies of detectable TT virus were observed already in patients with compensated/stable decompensated liver cirrhosis compared to healthy controls (>50% vs. 19%), suggesting relatively early occurrence of immunosuppression in cirrhosis. In line, profoundly reduced numbers of distinct innate and adaptive immune cell populations were observed before ACLF development. These changes were accompanied by parallel upregulation of co-stimulatory (e.g. CD40L, OX40, CD69, GITR, TIM-1) and inhibitory immune checkpoints (e.g. PDPN, PROCR, 2B4, TIGIT) on CD4+ and CD8+ T cells, which again preceded the development of ACLF. On a functional basis, the capacity of CD4+ and CD8+ T cells to produce pro-inflammatory cytokines upon stimulation was strongly diminished in patients with acute decompensation of liver cirrhosis and ACLF.
Impaired innate and-in particular-adaptive cellular immunity occurs relatively early in the pathogenesis of liver cirrhosis and precedes ACLF. This may contribute to the development of ACLF by increasing the risk of infections in patients with liver cirrhosis.
•International travel enables the spread of SARS-CoV-2 and its viral variants•The antigen test showed a sensitivity of 100% with respect to in vitro infectivity•An antigen test following quarantine ...effectively detects infectious travellers•Travel regulations rely heavily on test quality and compliance
International travel poses the risk of importing SARS-CoV-2 infections and introducing new viral variants into the country of destination. Established measures include mandatory quarantine with the opportunity to abbreviate it with a negative rapid antigen test (RAT).
A total of 1,488 returnees were tested for SARS-CoV-2 with both PCR and RAT no earlier than 5 days after arrival. We assessed the sensitivity and specificity of the RAT. Positive samples were evaluated for infectivity in vitro in a cell culture outgrowth assay. We tracked if participants who tested negative were reported positive within 2 weeks of the initial test.
Potential infectiousness was determined based on symptom onset analysis, resulting in a sensitivity of the antigen test of 89% in terms of infectivity. The specificity was 100%. All positive outgrowth assays were preceded by a positive RAT, indicating that all participants with proven in vitro infectivity were correctly identified. None of the negative participants tested positive during the follow-up.
RAT no earlier than the 5th day after arrival was a reliable method for detecting infectious travellers and can be recommended as an appropriate method for managing SARS-CoV-2 travel restrictions. Compliance to the regulations and a high standard of test quality must be ensured.
Wastewater-based SARS-CoV-2 epidemiology (WBE) has been established as an important tool to support individual testing strategies. The Omicron sub-variants BA.4/BA.5 have spread globally, displacing ...the preceding variants. Due to the severe transmissibility and immune escape potential of BA.4/BA.5, early monitoring was required to assess and implement countermeasures in time. In this study, we monitored the prevalence of SARS-CoV-2 BA.4/BA.5 at six municipal wastewater treatment plants (WWTPs) in the Federal State of North Rhine-Westphalia (NRW, Germany) in May and June 2022. Initially, L452R-specific primers/probes originally designed for SARS-CoV-2 Delta detection were validated using inactivated authentic viruses and evaluated for their suitability for detecting BA.4/BA.5. Subsequently, the assay was used for RT-qPCR analysis of RNA purified from wastewater obtained twice a week at six WWTPs. The occurrence of L452R carrying RNA was detected in early May 2022, and the presence of BA.4/BA.5 was confirmed by variant-specific single nucleotide polymorphism PCR (SNP-PCR) targeting E484A/F486V and NGS sequencing. Finally, the mutant fractions were quantitatively monitored by digital PCR, confirming BA.4/BA.5 as the majority variant by 5 June 2022. In conclusion, the successive workflow using RT-qPCR, variant-specific SNP-PCR, and RT-dPCR demonstrates the strength of WBE as a versatile tool to rapidly monitor variants spreading independently of individual test capacities.
The SARS-CoV-2 pandemic has affected nations globally leading to illness, death, and economic downturn. Why disease severity, ranging from no symptoms to the requirement for extracorporeal membrane ...oxygenation, varies between patients is still incompletely understood. Consequently, we aimed at understanding the impact of genetic factors on disease severity in infection with SARS-CoV-2. Here, we provide data on demographics, ABO blood group, human leukocyte antigen (HLA) type, as well as next-generation sequencing data of genes in the natural killer cell receptor family, the renin-angiotensin-aldosterone and kallikrein-kinin systems and others in 159 patients with SARS-CoV-2 infection, stratified into seven categories of disease severity. We provide single-nucleotide polymorphism (SNP) data on the patients and a protein structural analysis as a case study on a SNP in the SIGLEC7 gene, which was significantly associated with the clinical score. Our data represent a resource for correlation analyses involving genetic factors and disease severity and may help predict outcomes in infections with future SARS-CoV-2 variants and aid vaccine adaptation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Previous studies reported on the safety and applicability of mesenchymal stem/stromal cells (MSCs) to ameliorate pulmonary inflammation in acute respiratory distress syndrome (ARDS). Thus, multiple ...clinical trials assessing the potential of MSCs for COVID-19 treatment are underway. Yet, as SARS-inducing coronaviruses infect stem/progenitor cells, it is unclear whether MSCs could be infected by SARS-CoV-2 upon transplantation to COVID-19 patients. We found that MSCs from bone marrow, amniotic fluid, and adipose tissue carry angiotensin-converting enzyme 2 and transmembrane protease serine subtype 2 at low levels on the cell surface under steady-state and inflammatory conditions. We did not observe SARS-CoV-2 infection or replication in MSCs at steady state under inflammatory conditions, or in direct contact with SARS-CoV-2-infected Caco-2 cells. Further, indoleamine 2,3-dioxygenase 1 production in MSCs was not impaired in the presence of SARS-CoV-2. We show that MSCs are resistant to SARS-CoV-2 infection and retain their immunomodulation potential, supporting their potential applicability for COVID-19 treatment.
•MSCs carry ACE2 and TMPRSS2 only at very low levels on the cell surface•Inflammatory conditions do not change ACE2 and TMPRSS2 expression on MSCs•MSCs are resistant to SARS-CoV-2 infection•MSCs retain their immunomodulation potential in the presence of SARS-CoV-2
Schäfer and colleagues found that human MSCs carry ACE 2 and TMPRSS2 at very low levels on the cell surface under steady-state and inflammatory conditions. Using their in vitro model for infection with SARS-CoV-2 from clinical isolates they show that MSC are resistant to SARS-CoV-2 infection and retain their immunomodulation potential supporting their potential applicability for COVID-19 treatment.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. The ...common methods to monitor and quantitate SARS-CoV-2 infectivity in cell culture are so far time-consuming and labor-intensive. Using the Sleeping Beauty transposase system, we generated a robust and versatile cellular infection model that allows SARS-CoV-2 infection experiments compatible for high-throughput and live cell imaging. The model is based on lung derived A549 cells, which show a profound interferon response and convenient cell culture characteristics. ACE2 and TMPRSS2 were introduced for constitutive expression (A549-AT). Subclones with varying levels of ACE2/TMPRSS2 were screened for optimal SARS-CoV-2 susceptibility. Furthermore, extensive evaluation demonstrated that SARS-CoV-2 infected A549-AT cells were distinguishable from mock-infected cells and already showed approximately 12 h post infection a clear signal to noise ratio in terms of cell roughness, fluorescence and a profound visible cytopathic effect. Moreover, due to the high transfection efficiency and proliferation capacity, Sleeping Beauty transposase-based overexpression cell lines with a second inducible fluorescence reporter cassette (eGFP) can be generated in a very short time, enabling the investigation of host and restriction factors in a doxycycline-inducible manner. Thus, the novel model cell line allows rapid and sensitive monitoring of SARS-CoV-2 infection and the screening for host factors essential for viral replication.
•Heterologous vaccination showed an acceptable reactogenicity and immunogenicity.•Heterologous (ChAdOx1-S/BNT162b2) vaccination temporarily led to higher neutralizing activity than homologous ...messenger RNA vaccination.•A third dose of a messenger RNA vaccine maintains neutralizing activity against SARS-CoV-2.•SARS-CoV-2 variant of concern-adapted versions of the vaccines would be desirable.
Regarding reactogenicity and immunogenicity, heterologous COVID-19 vaccination regimens are considered as an alternative to conventional immunization schemes.
Individuals receiving either heterologous (ChAdOx1-S AstraZeneca, Cambridge, UK/BNT162b2 Pfizer-BioNTech, Mainz, Germany; n = 306) or homologous (messenger RNA mRNA-1273 Moderna, Cambridge, Massachusetts, USA; n = 139) vaccination were asked to participate when receiving their second dose. Reactogenicity was assessed after 1 month, immunogenicity after 1, 3, and/or 6 months, including a third dose, through SARS-CoV-2 antispike immunoglobulin G, surrogate virus neutralization test, and a plaque reduction neutralization test against the Delta (B.1.167.2) and Omicron (B.1.1.529; BA.1) variants of concern.
The overall reactogenicity was lower after heterologous vaccination. In both cohorts, SARS-CoV-2 antispike immunoglobulin G concentrations waned over time with the heterologous vaccination demonstrating higher neutralizing activity than homologous mRNA vaccination after 3 months to low neutralizing levels in the Delta plaque reduction neutralization test after 6 months. At this point, 3.2% of the heterologous and 11.4% of the homologous cohort yielded low neutralizing activity against Omicron. After a third dose of an mRNA vaccine, ≥99% of vaccinees demonstrated positive neutralizing activity against Delta. Depending on the vaccination scheme and against Omicron, 60% to 87.5% of vaccinees demonstrated positive neutralizing activity.
ChAdOx1-S/BNT162b2 vaccination demonstrated an acceptable reactogenicity and immunogenicity profile. A third dose of an mRNA vaccine is necessary to maintain neutralizing activity against SARS-CoV-2. However, variants of concern-adapted versions of the vaccines would be desirable.
SARS-CoV-2 is the causative agent of COVID-19. Timely and accurate diagnostic testing is vital to contain the spread of infection, reduce delays in treatment and care, and inform patient management. ...Optimal specimen type (e.g. nasal swabs or saliva), timing of sampling, viral marker assayed (RNA or antigen), and correlation with viral infectivity and COVID-19 symptoms severity remain incompletely defined. We conducted a field study to evaluate SARS-CoV-2 viral marker kinetics starting from very early times after infection. We measured RNA and antigen levels in nasal swabs and saliva, virus outgrowth in cell culture from nasal swabs, and antibody levels in blood in a cohort of 30 households. Nine household contacts (HHC) became infected with SARS-CoV-2 during the study. Viral RNA was detected in saliva specimens approximately 1-2 days before nasal swabs in six HHC. Detection of RNA was more sensitive than of antigen, but antigen detection was better correlated with culture positivity, a proxy for contagiousness. Anti-nucleocapsid antibodies peaked one to three weeks post-infection. Viral RNA and antigen levels were higher in specimens yielding replication competent virus in cell culture. This study provides important data that can inform how to optimally interpret SARS-CoV-2 diagnostic test results.
SARS-CoV-2 uses the human cell surface protein angiotensin converting enzyme 2 (ACE2) as the receptor by which it gains access into lung and other tissue. Early in the pandemic, there was speculation ...that a number of commonly used medications-including ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs)-have the potential to upregulate ACE2, thereby possibly facilitating viral entry and increasing the severity of COVID-19. We investigated the influence of the NSAIDS with a range of cyclooxygenase (COX)1 and COX2 selectivity (ibuprofen, flurbiprofen, etoricoxib) and paracetamol on the level of ACE2 mRNA/protein expression and activity as well as their influence on SARS-CoV-2 infection levels in a Caco-2 cell model. We also analysed the ACE2 mRNA/protein levels and activity in lung, heart and aorta in ibuprofen treated mice. The drugs had no effect on ACE2 mRNA/protein expression and activity in the Caco-2 cell model. There was no up-regulation of ACE2 mRNA/protein expression and activity in lung, heart and aorta tissue in ibuprofen-treated mice in comparison to untreated mice. Viral load was significantly reduced by both flurbiprofen and ibuprofen at high concentrations. Ibuprofen, flurbiprofen, etoricoxib and paracetamol demonstrated no effects on ACE2 expression or activity in vitro or in vivo. Higher concentrations of ibuprofen and flurbiprofen reduced SARS-CoV-2 replication in vitro.
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