Laboratory detection of SARS-CoV-2: A review of the current literature and future perspectives.

Nowadays, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), whose infectivity is awfully strong, has been a major global threat to the public health. Since lung is the major target of SARS-CoV-2, the infection can lead to respiratory distress syndrome (RDS), multiple organ failure (MOF), and even death. The studies on viral structure and infection mechanism have found that angiotensin-converting enzyme 2 (ACE2), a pivotal enzyme affecting the organ-targeting in the RAS system, is the receptor of the SARS-CoV-2 virus. Currently, the detection of SARSCoV-2 is mainly achieved using open plate real-time reverse-transcription polymerase chain reaction (RT-PCR). While open plate method has some limitations, such as a high false-negative rate, cumbersome manual operation, aerosol pollution and leakage risks. Therefore, a convenient method to rapidly detect SARS-CoV-2 virus is urgently and extremely required for timely epidemic control with the limited resources. In this review, the current real-time methods and principles for novel coronavirus detection are summarized, with the aim to provide a reference for real-time screening of coronavirus in areas with insufficient detection capacity and inadequate medical resources. The development and establishment of a rapid, simple, sensitive and specific system to detect SARS-CoV-2 is of vital importance for distinct diagnosis and effective treatment of the virus, especially in the flu season.

Laboratory detection of SARS-CoV-2: A review of the current literature and future perspectives

Nowadays, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), whose infectivity is awfully strong, has been a major global threat to the public health. Since lung is the major target of SARS-CoV-2, the infection can lead to respiratory distress syndrome (RDS), multiple organ failure (MOF), and even death. The studies on viral structure and infection mechanism have found that angiotensin-converting enzyme 2 (ACE2), a pivotal enzyme affecting the organ-targeting in the RAS system, is the receptor of the SARS-CoV-2 virus. Currently, the detection of SARSCoV-2 is mainly achieved using open plate real-time reverse-transcription polymerase chain reaction (RT-PCR). While open plate method has some limitations, such as a high false-negative rate, cumbersome manual operation, aerosol pollution and leakage risks. Therefore, a convenient method to rapidly detect SARS-CoV-2 virus is urgently and extremely required for timely epidemic control with the limited resources. In this review, the current real-time methods and principles for novel coronavirus detection are summarized, with the aim to provide a reference for real-time screening of coronavirus in areas with insufficient detection capacity and inadequate medical resources. The development and establishment of a rapid, simple, sensitive and specific system to detect SARS-CoV-2 is of vital importance for distinct diagnosis and effective treatment of the virus, especially in the flu season. Novel coronavirus;SARS-CoV-2;Gene sequencing;Nucleic acid testing;Gene editing techniques.

Luteolin transforms the polarity of bone marrow-derived macrophages to regulate the cytokine storm.

BACKGROUND: Macrophages are indispensable regulators of inflammatory responses. Macrophage polarisation and their secreted inflammatory factors have an association with the outcome of inflammation. Luteolin, a flavonoid abundant in plants, has anti-inflammatory activity, but whether luteolin can manipulate M1/M2 polarisation of bone marrow-derived macrophages (BMDMs) to suppress inflammation is still unclear. This study aimed to observe the effects of luteolin on the polarity of BMDMs derived from C57BL/6 mice and the expression of inflammatory factors, to explore the mechanism by which luteolin regulates the BMDM polarity. METHODS: M1-polarised BMDMs were induced by lipopolysaccharide (LPS) + interferon (IFN)-γ and M2-polarisation were stimulated with interleukin (IL)-4. BMDM morphology and phagocytosis were observed by laser confocal microscopy; levels of BMDM differentiation and cluster of differentiation (CD)11c or CD206 on the membrane surface were assessed by flow cytometry (FCM); mRNA and protein levels of M1/M2-type inflammatory factors were performed by qPCR and ELISA, respectively; and the expression of p-STAT1 and p-STAT6 protein pathways was detected by Western-blotting. RESULTS: The isolated mouse bone marrow cells were successfully differentiated into BMDMs, LPS + IFN-γ induced BMDM M1-phenotype polarisation, and IL-4 induced M2-phenotype polarisation. After M1-polarised BMDMs were treated with luteolin, the phagocytosis of M1-polarized BMDMs was reduced, and the M1-type pro-inflammatory factors including IL-6, tumour necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), and CD86 were downregulated while the M2-type anti-inflammatory factors including IL-10, IL-13, found in inflammatory zone (FIZZ)1, Arginase (Arg)1 and CD206 were upregulated. Additionally, the expression of M1-type surface marker CD11c decreased. Nevertheless, the M2-type marker CD206 increased; and the levels of inflammatory signalling proteins phosphorylated signal transducer and activator of transcription (p-STAT)1 and p-STAT6 were attenuated and enhanced, respectively. CONCLUSIONS: Our study suggests that luteolin may transform BMDM polarity through p-STAT1/6 to regulate the expression of inflammatory mediators, thereby inhibiting inflammation. Naturally occurring luteolin holds promise as an anti-inflammatory and immunomodulatory agent.

Pathogenesis of COVID-19 and the quality control of nucleic acid detection.

The new coronavirus pneumonia (COVID-19) epidemic spread rapidly throughout the world. Considering the strong infectivity and clustering of COVID-19, early detection of infectious cases is of great significance to control the epidemic. Nucleic acid testing (NAT) plays an important role in rapid laboratory diagnosis, treatment assessment, epidemic prevention and control of COVID-19. However, since COVID-19 is caused by a new emerging virus and NAT for COVID-19 has not been clinically applied before, false negative results inconsistent with clinical diagnosis have appeared in clinical practice. Therefore, it is urgent to improve the sensitivity of NAT for COVID-19. This study aimed to summarize the current situation and prospect of NAT based on the latest findings on COVID-19 infection. Also, the quality control of sample collection was discussed. Hopefully, this study could help to improve the effectiveness of NAT for COVID-19.