Identification of Host Proteins Interacting with IBV S1 Based on Tracheal Organ Culture.

Infectious bronchitis virus (IBV) belongs to the gamma-coronavirus genus of Coronaviridae and causes serious infectious diseases in the poultry industry. However, only a few IBV strains can infect avian passage cell lines, seriously hindering the progress of basic research on IBV pathogenesis. Whereas IBV field strains can replicate in tracheal ring organ culture (TOC) without any previous adaptation in chicken embryos or primary cells. In this study, to investigate the potential use of TOC as an in vitro infection model for the study of IBV-host interaction, we first established a chicken embryo TOC culture system and carried out an investigation on the IBV replication kinetics in the system. We found that the selected strains of the IBV GI-1, GI-7, GI-13, GI-19, and GI-22 genotypes could successfully replicate in TOC and bring about damage to the infected trachea. Next, we identified host proteins of the chicken embryo trachea that interact with the IBV S1 protein by immunoprecipitation and protein mass spectrometry. A total of 127 candidate proteins were initially identified with major involvement in cell adhesion pathways and apoptosis- and autophagy-related pathways. The heat shock protein 70 (HSP70) was selected for further investigation in the interaction with IBV viral proteins. Our results showed that HSP70 interacted with IBV S1 in both TOC and CEK cells, whereas HSP70 overexpression inhibited viral replication. This study indicates that TOC is a good system for the elucidation of IBV-host interactions and HSP70 is a potential host antiviral factor.

Pathogenicity analysis of one avian infectious bronchitis virus stain isolated from Shanxi

In order to perform the isolation of avian infectious bronchitis virus (IBV) and study the pathogenicity of IBV isolate, the RT-PCR was used to detect nucleic acid extracted from a clinical sample of chickens, which were suspected to be infected with infectious bronchitis virus (IBV) and provided by a farmer in Yuncheng, Shanxi province. And the sample was detected as IBV positive by RT-PCR. Then 9-11-day-old SPF chicken embryonated eggs were inoculated with the sample filtered from the grinding fluid, and the obtained allantoic fluid was blindly passed by three generations (F3) and was also tested as IBV positive;The F11 generation passaged in embryonated eggs caused typical "dwarf embryo" lesions to SPF chicken embryonated eggs, and induced the loss of cilia in tracheal rings. The results showed that an IBV strain was isolated and named as YC181031. The S1 gene amplification and sequencing analysis showed that YC181031 strain belonged to IBV GI-22 genotype, which is also nephropathogenic type IBV. Seven-day-old SPF chicks were used to test the pathogenicity of the isolate. The results showed that several clinical symptoms were showed in chicks infected with YC181031, such as breathing with difficulty, depression, excreting watery droppings and death. The mortality of infected chicks was 20%. Typical pathological changes such as enlargement of kidney and urate deposition in the kidney were observed in infected chicks. The immunohistochemical assay and viral load detection were performed for the tissue samples from infected and dead chicks. The tissue lesions and distribution of virus were observed in the kidney, trachea, lung, glandular stomach, spleen and liver samples of infected chicks. RT-PCR detection of pharyngeal anal swabs showed that the virus shedding by infected chicks could be continuously detected within 14 days of the test period;The viral loads of various tissues were detected by RT-qPCR and the results showed that the viral load from high to low was kidney, trachea, lung, stomach, spleen and liver. The viral load of kidney was significantly higher than that of other tissues (P < 0.05).In this study, the pathogenicity characteristics of GI-22 genotype strain were systematically studied for the first time, providing a reference for the prevention and treatment of the disease.

Epidemiological characteristics of a local COVID-19 outbreak caused by omicron variant (BA.2) in Qinzhou, Guangxi

Objective: To analyze the epidemiological characteristics of a local COVID-19 outbreak in Qinzhou, Guangxi Zhuang autonomous region, and provide reference for the prevention and control of COVID-19 in the future. Methods The epidemiological and clinical information, analysis reports and laboratory test results of the COVID-19 cases were collected for a descriptive epidemiological analysis. Results A total of 97 COVID-19 cases, including 79 asymptomatic cases and 18 confirmed cases, were reported in Qinzhou during 12-24 March, 2022. Forty nine cases were males and 48 cases were females. The median of age of the cases was 32 (17.0, 44.5) years. The median of incubation period was 3 days. The median of latent period was 2 days. A total of 3841 close contacts were screened, in whom 61 were infected. The secondary attack rates in 3841 close contacts was 1.59%. The secondary attack rate in household contacts was 65% in 8 family clustering (95% CL: 20%-100%). Three mass gathering were identified in a local recreation center box, a wedding ceremony and a family feast for new home, in which the attack rates were 63.64%, 9.38% and 12.16%, respectively. Transmission firstly occurred in the people attending the activity in the recreation center box. At least 5 generations of transmission were identified in the outbreak. The results of genome second generation sequencing of the isolates from 20 infection cases revealed that the pathogen of the outbreak was SARS-CoV-2 Omicron variant (BA.2). Conclusion Analysis on the cases caused by Omicron variant (BA.2) indicated early prevention measures are important for the control of further spread of COVID-19.

An important call: Suggestion of using IL-10 as therapeutic agent for COVID-19 with ARDS and other complications.

The global coronavirus disease 2019 (COVID-19) pandemic has a detrimental impact on public health. COVID-19 usually manifests as pneumonia, which can progress into acute respiratory distress syndrome (ARDS) related to uncontrolled TH17 immune reaction. Currently, there is no effective therapeutic agent to manage COVID-19 with complications. The currently available anti-viral drug remdesivir has an effectiveness of 30% in SARS-CoV-2-induced severe complications. Thus, there is a need to identify effective agents to treat COVID-19 and the associated acute lung injury and other complications. The host immunological pathway against this virus typically involves the THαß immune response. THαß immunity is triggered by type 1 interferon and interleukin-27 (IL-27), and the main effector cells of the THαß immune response are IL10-CD4 T cells, CD8 T cells, NK cells, and IgG1-producing B cells. In particular, IL-10 exerts a potent immunomodulatory or anti-inflammatory effect and is an anti-fibrotic agent for pulmonary fibrosis. Concurrently, IL-10 can ameliorate acute lung injury or ARDS, especially those caused by viruses. Owing to its anti-viral activity and anti-pro-inflammatory effects, in this review, IL-10 is suggested as a possible treatment agent for COVID-19.

The Perspective of Vitamin D on suPAR-Related AKI in COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of millions of people around the world. Severe vitamin D deficiency can increase the risk of death in people with COVID-19. There is growing evidence that acute kidney injury (AKI) is common in COVID-19 patients and is associated with poorer clinical outcomes. The kidney effects of SARS-CoV-2 are directly mediated by angiotensin 2-converting enzyme (ACE2) receptors. AKI is also caused by indirect causes such as the hypercoagulable state and microvascular thrombosis. The increased release of soluble urokinase-type plasminogen activator receptor (suPAR) from immature myeloid cells reduces plasminogen activation by the competitive inhibition of urokinase-type plasminogen activator, which results in low plasmin levels and a fibrinolytic state in COVID-19. Frequent hypercoagulability in critically ill patients with COVID-19 may exacerbate the severity of thrombosis. Versican expression in proximal tubular cells leads to the proliferation of interstitial fibroblasts through the C3a and suPAR pathways. Vitamin D attenuates the local expression of podocyte uPAR and decreases elevated circulating suPAR levels caused by systemic inflammation. This decrease preserves the function and structure of the glomerular barrier, thereby maintaining renal function. The attenuated hyperinflammatory state reduces complement activation, resulting in lower serum C3a levels. Vitamin D can also protect against COVID-19 by modulating innate and adaptive immunity, increasing ACE2 expression, and inhibiting the renin-angiotensin-aldosterone system. We hypothesized that by reducing suPAR levels, appropriate vitamin D supplementation could prevent the progression and reduce the severity of AKI in COVID-19 patients, although the data available require further elucidation.

Immunothrombosis biomarkers as potential predictive factors of acute respiratory distress syndrome in moderate-to-critical COVID-19: A single-center, retrospective cohort study.

BACKGROUND: Immunothrombosis, a process of inflammation and coagulation, is involved in sepsis-induced acute respiratory distress syndrome formation (ARDS). However, the clinical correlation between immunothrombosis biomarkers (including tissue factor [TF] and von Willebrand factor [vWF]) and coronavirus disease 2019 (COVID-19)-related ARDS is unknown. This study investigated ARDS development following moderate-to-critical COVID-19 and examined immunothrombosis biomarkers as ARDS predictors. METHODS: This retrospective cohort study included patients with moderate-to-critical COVID-19 (n = 165) admitted to a northern teaching hospital during the 2021 pandemic in Taiwan, who had no COVID-19 vaccinations. Immunothrombosis biomarkers were compared between COVID-19 patients with and without ARDS (no-ARDS) and a control group consisting of 100 healthy individuals. RESULTS: The study included 58 ARDS and 107 no-ARDS patients. In multivariable analysis, TF (aOR=1.031, 95% CI: 1.009-1.053, p = 0.006); and vWF (aOR=1.053, 95% CI: 1.002-1.105, p = 0.041) were significantly associated with ARDS episodes, after adjusting for other confounding factors. vWF and TF predicted ARDS with the area under the curve of 0.870 (95% CI: 0.796-0.945). Further mechanical ventilation analysis found TF to be correlated significantly with pCO2 and ventilatory ratio. CONCLUSIONS: TF and vWF levels potentially predicted ARDS development within 7 days of admission for COVID-19 after adjusting for traditional risk factors. TF correlated with ventilation impairment in COVID-19 ARDS but further prospective studies are needed.

Effect of HSP90AB1 on the replication of avian infectious bronchitis virus

The effects of heat shock protein HSPQOABl on the replication of avian infectious bronchitis virus(AIBV) were confirmed by using over expression and RNA interference methods. The results showed that over expression of HSPQOABI inhibited AIBV replication, whereas knockdown of HSPQOABl in- creased AIBV replication. These results indicated that HSPQOABI is a potential anti-viral host factor. These findings provide the basis for further study of the pathogenic mechanism of AIBV and anti-coronavirus infection.

A Review of the Potential Effects of Melatonin in Compromised Mitochondrial Redox Activities in Elderly Patients With COVID-19.

Melatonin, an endogenous indoleamine, is an antioxidant and anti-inflammatory molecule widely distributed in the body. It efficiently regulates pro-inflammatory and anti-inflammatory cytokines under various pathophysiological conditions. The melatonin rhythm, which is strongly associated with oxidative lesions and mitochondrial dysfunction, is also observed during the biological process of aging. Melatonin levels decline considerably with age and are related to numerous age-related illnesses. The signs of aging, including immune aging, increased basal inflammation, mitochondrial dysfunction, significant telomeric abrasion, and disrupted autophagy, contribute to the increased severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These characteristics can worsen the pathophysiological response of the elderly to SARS-CoV-2 and pose an additional risk of accelerating biological aging even after recovery. This review explains that the death rate of coronavirus disease (COVID-19) increases with chronic diseases and age, and the decline in melatonin levels, which is closely related to the mitochondrial dysfunction in the patient, affects the virus-related death rate. Further, melatonin can enhance mitochondrial function and limit virus-related diseases. Hence, melatonin supplementation in older people may be beneficial for the treatment of COVID-19.

The Role of Vitamin D in SARS-CoV-2 Infection and Acute Kidney Injury.

Vitamin D has been described as an essential nutrient and hormone, which can cause nuclear, non-genomic, and mitochondrial effects. Vitamin D not only controls the transcription of thousands of genes, directly or indirectly through the modulation of calcium fluxes, but it also influences the cell metabolism and maintenance specific nuclear programs. Given its broad spectrum of activity and multiple molecular targets, a deficiency of vitamin D can be involved in many pathologies. Vitamin D deficiency also influences mortality and multiple outcomes in chronic kidney disease (CKD). Active and native vitamin D serum levels are also decreased in critically ill patients and are associated with acute kidney injury (AKI) and in-hospital mortality. In addition to regulating calcium and phosphate homeostasis, vitamin D-related mechanisms regulate adaptive and innate immunity. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have a role in excessive proinflammatory cell recruitment and cytokine release, which contribute to alveolar and full-body endothelial damage. AKI is one of the most common extrapulmonary manifestations of severe coronavirus disease 2019 (COVID-19). There are also some correlations between the vitamin D level and COVID-19 severity via several pathways. Proper vitamin D supplementation may be an attractive therapeutic strategy for AKI and has the benefits of low cost and low risk of toxicity and side effects.

First evidence that an emerging mammalian alphacoronavirus is able to infect an avian species.

A novel swine enteric alphacoronavirus, swine acute diarrhoea syndrome coronavirus (SADS-CoV), related to Rhinolophus bat CoV HKU2 in the subgenus Rhinacovirus emerged in southern China in 2017, causing diarrhoea in newborn piglets, and critical questions remain about the pathogenicity, cross-species transmission and potential animal reservoirs. Our laboratory's previous research has shown that SADS-CoV can replicate in various cell types from different species, including chickens. Here, we systematically explore the susceptibility of chickens to a cell-adapted SADS-CoV strain both in vitro and in vivo. First, evidence of SADS-CoV replication in primary chicken cells, including cytopathic effects, immunofluorescence staining, growth curves and structural protein expression, was proven. Furthermore, we observed that SADS-CoV replicated in chicken embryos without causing gross lesions and that experimental infection of chicks resulted in mild respiratory symptoms. More importantly, SADS-CoV shedding and viral distribution in the lungs, spleens, small intestines and large intestines of infected chickens were confirmed by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. The genomic sequence of the original SADS-CoV from the pig source sample in 2017 was determined to have nine nucleotide differences compared to the cell-adapted strain used; among these were three nonsynonymous mutations in the spike gene. These results collectively demonstrate that chickens are susceptible to SADS-CoV infection, suggesting that they are a potential animal reservoir. To our knowledge, this study provides the first experimental evidence of cross-species infection in which a mammalian alphacoronavirus is able to infect an avian species.

Resveratrol as an Adjunctive Therapy for Excessive Oxidative Stress in Aging COVID-19 Patients.

The coronavirus disease 2019 (COVID-19) pandemic continues to burden healthcare systems worldwide. COVID-19 symptoms are highly heterogeneous, and the patient may be asymptomatic or may present with mild to severe or fatal symptoms. Factors, such as age, sex, and comorbidities, are key determinants of illness severity and progression. Aging is accompanied by multiple deficiencies in interferon production by dendritic cells or macrophages in response to viral infections, resulting in dysregulation of inflammatory immune responses and excess oxidative stress. Age-related dysregulation of immune function may cause a more obvious pathophysiological response to SARS-CoV-2 infection in elderly patients and may accelerate the risk of biological aging, even after recovery. For more favorable treatment outcomes, inhibiting viral replication and dampening inflammatory and oxidative responses before induction of an overt cytokine storm is crucial. Resveratrol is a potent antioxidant with antiviral activity. Herein, we describe the reasons for impaired interferon production, owing to aging, and the impact of aging on innate and adaptive immune responses to infection, which leads to inflammation distress and immunosuppression, thereby causing fulminant disease. Additionally, the molecular mechanism by which resveratrol could reverse a state of excessive basal inflammatory and oxidative stress and low antiviral immunity is discussed.

Physical activity, screen exposure and sleep among students during the pandemic of COVID-19.

This study aimed to determine the levels of health-related behaviours (physical activity, screen exposure and sleep status) among Chinese students from primary, secondary and high schools during the pandemic of COVID-19, as well as their changes compared with their status before the pandemic. A cross-sectional online survey of 10,933 students was conducted among 10 schools in Guangzhou, China, between 8th and 15th March, 2020. After getting the informed consent from student's caregivers, an online questionnaire was designed and used to obtain time spending on health-related behaviours during the pandemic of COVID-19, as well as the changes compared with 3 months before the pandemic, which was completed by students themselves or their caregivers. Students were stratified by regions (urban, suburban, exurban), gender (boys and girls), and grades (lower grades of primary school, higher grades of primary schools, secondary schools and high schools). Data were expressed as number and percentages and Chi-square test was used to analyse difference between groups. Overall, the response rate of questionnaire was 95.3% (10,416/10,933). The median age of included students was 13.0 (10.0, 16.0) years and 50.1% (n = 5,219) were boys. 41.4%, 53.6% and 53.7% of total students reported less than 15 min per day in light, moderate and vigorous activities and 58.7% (n = 6,113) reported decreased participation in physical activity compared with the time before pandemic. Over 5 h of screen time spending on online study was reported by 44.6% (n = 4,649) of respondents, particular among high school students (81.0%). 76.9% of students reported increased screen time compared with the time before pandemic. Inadequate sleep was identified among 38.5% of students and the proportion was highest in high school students (56.9%). Our study indicated that, during the COVID-19 pandemic, the school closure exerted tremendous negative effects on school-aged children's health habits, including less physical activity, longer screen exposure and irregular sleeping pattern.

Real-time neural network scheduling of emergency medical mask production during COVID-19.

During the outbreak of the novel coronavirus pneumonia (COVID-19), there is a huge demand for medical masks. A mask manufacturer often receives a large amount of orders that must be processed within a short response time. It is of critical importance for the manufacturer to schedule and reschedule mask production tasks as efficiently as possible. However, when the number of tasks is large, most existing scheduling algorithms require very long computational time and, therefore, cannot meet the needs of emergency response. In this paper, we propose an end-to-end neural network, which takes a sequence of production tasks as inputs and produces a schedule of tasks in a real-time manner. The network is trained by reinforcement learning using the negative total tardiness as the reward signal. We applied the proposed approach to schedule emergency production tasks for a medical mask manufacturer during the peak of COVID-19 in China. Computational results show that the neural network scheduler can solve problem instances with hundreds of tasks within seconds. The objective function value obtained by the neural network scheduler is significantly better than those of existing constructive heuristics, and is close to those of the state-of-the-art metaheuristics whose computational time is unaffordable in practice.