Emerging microbes & infections
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Emerg Microbes Infect · Dec 2021
ReviewThe interplay between emerging human coronavirus infections and autophagy.
ABSTRACT Following outbreaks of severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV) in 2002 and 2012, respectively, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the third highly pathogenic emerging human coronavirus (hCoV). SARS-CoV-2 is currently causing the global coronavirus disease 2019 (COVID-19) pandemic. CoV infections in target cells may stimulate the formation of numerous double-membrane autophagosomes and induce autophagy. ⋯ However, so far it is unclear how hCoV infections induce autophagy and whether the autophagic machinery is necessary for viral propagation. Here, we summarize the most recent advances concerning the mutual interplay between the autophagic machinery and the three emerging hCoVs, SARS-CoV, MERS-CoV, and SARS-CoV-2 and the model system mouse hepatitis virus. We also discuss the applicability of approved and well-tolerated drugs targeting autophagy as a potential treatment against COVID-19.
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Emerg Microbes Infect · Dec 2021
ReviewCOVID-19-associated cytokine storm syndrome and diagnostic principles: an old and new Issue.
SARS-CoV-2 has claimed 2,137,908 lives in more than a year. Some COVID-19 patients experience sudden and rapid deterioration with the onset of fatal cytokine storm syndrome (CSS), which have increased interest in CSS's mechanisms, diagnosis and therapy. Although the prototypic concept of CSS was first proposed 116 years ago, we have only begun to study and understand CSS for less than 30 years. ⋯ The paper concisely comment evolution of CSS classifications, cytokines associated with CSS, evolution of CSS diagnostic criteria and importance of the correct identification of hemophagocytes in diagnosing CSS, which is timely and may benefit clinicians familiar HLH-2004/2009 diagnostic criteria, and HScore methods. In addition, clinicians must also understand that there are some limitations to these diagnostic criteria. Abbreviations: aBMT: autologous bone marrow transplantation; CAR-T: chimeric antigen receptor-engineered T-cell; COVID-19: coronavirus disease 2019; CSS: cytokine storm syndrome; HLH: hemophagocytic lymphohistiocytosis; MAS: macrophage activation syndrome; CRS: cytokine release syndrome; CS: cytokine storm; MAHS: malignancy-associated hemophagocytic syndrome; IAHS: infection-associated hemophagocytic syndrome; fHLH/pHLH: familial/primary hemophagocytic lymphohistiocytosis; sHLH: secondary hemophagocytic lymphohistiocytosis; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2; TCR-T, T-cell receptor-engineered T-cell.
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Emerg Microbes Infect · Dec 2021
ReviewLessons learned one year after SARS-CoV-2 emergence leading to COVID-19 pandemic.
Without modern medical management and vaccines, the severity of the Coronavirus Disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) might approach the magnitude of 1894-plague (12 million deaths) and 1918-A(H1N1) influenza (50 million deaths) pandemics. The COVID-19 pandemic was heralded by the 2003 SARS epidemic which led to the discovery of human and civet SARS-CoV-1, bat SARS-related-CoVs, Middle East respiratory syndrome (MERS)-related bat CoV HKU4 and HKU5, and other novel animal coronaviruses. The suspected animal-to-human jumping of 4 betacoronaviruses including the human coronaviruses OC43(1890), SARS-CoV-1(2003), MERS-CoV(2012), and SARS-CoV-2(2019) indicates their significant pandemic potential. ⋯ The possibility of emergence of a hypothetical SARS-CoV-3 or other novel viruses from animals or laboratories, and therefore needs for global preparedness should not be ignored. We reviewed representative publications on the epidemiology, virology, clinical manifestations, pathology, laboratory diagnostics, treatment, vaccination, and infection control of COVID-19 as of 20 January 2021, which is 1 year after person-to-person transmission of SARS-CoV-2 was announced. The difficulties of mass testing, labour-intensive contact tracing, importance of compliance to universal masking, low efficacy of antiviral treatment for severe disease, possibilities of vaccine or antiviral-resistant virus variants and SARS-CoV-2 becoming another common cold coronavirus are discussed.
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Emerg Microbes Infect · Dec 2021
Cross-reactive antibody against human coronavirus OC43 spike protein correlates with disease severity in COVID-19 patients: a retrospective study.
Seasonal human coronaviruses (HCoVs) including HCoV-229E, -OC43, -NL63, and -HKU1 widely spread in global human populations. However, the relevance of humoral response against seasonal HCoVs to COVID-19 pathogenesis is elusive. In this study, we profiled the temporal changes of IgG antibody against spike proteins (S-IgG) of SARS-CoV-2 and seasonal HCoVs in 838 plasma samples collected from 344 COVID-19 patients. ⋯ Higher levels of HCoV-OC43 S-IgG were also observed in patients requiring mechanical ventilation. At days 1-10 PSO, HCoV-OC43 S-IgG titres correlated to disease severity in the age group over 60. Our data indicate that there is a correlation between cross-reactive antibody against HCoV-OC43 spike protein and disease severity in COVID-19 patients.
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Emerg Microbes Infect · Dec 2021
Serological investigation of asymptomatic cases of SARS-CoV-2 infection reveals weak and declining antibody responses.
Without an effective vaccine against SARS-CoV-2, the build-up of herd immunity through natural infection has been suggested as a means to control COVID-19. Although population immunity is typically estimated by the serological investigation of recovered patients, humoral immunity in asymptomatic subjects has not been well studied, although they represent a large proportion of all SARS-CoV-2 infection cases. In this study, we conducted a serosurvey of asymptomatic infections among food workers and performed serological and cellular response analyses of asymptomatic subjects in Wuhan, the original epicenter of the COVID-19 outbreak. ⋯ Furthermore, the asymptomatic subjects showed lymphopenia and a prominent decrease in the B-cell population, as well as a low frequency of antibody-secreting cells and a low cytokine response. These factors probably contributed to the low and unsustained antibody levels in asymptomatic subjects. Our results show that asymptomatic subjects are likely to be vulnerable to SARS-CoV-2 reinfection, and neither the proportion of population immunity nor the breadth of immune responses is sufficient for herd immunity.