Objective To investigate the inhibitory effect of IFN-γ on acute allergic airway inflammation induced by IL-33 in mice.Methods Twenty-four female C57BL/6 mice (6-8 weeks) were randomly divided into four groups: IL-33 model group, IFN-γ treatment group, IL-33+IFN-γ treatment group and PBS control group.A mouse model of acute allergic airway inflammation was induced by IL-33.Samples of bronchial alveolar lavage fluid (BALF) and lung tissues were collected.Group 2 innate lymphoid cells (ILC2s) and eosinophils were analyzed by flow cytometry.Levels of IL-5 and IL-13 in the supernatants of lung homogenate and BALF were measured by ELISA.Expression of IL-5, IL-13 and ST2 at mRNA level was detected by real-time PCR.Pathological changes in lung tissues were observed following hematoxylin and eosin (HE) and periodic acid-Schiff (PAS) staining.Results Compared with the PBS control group, no infiltration with inflammatory cells, goblet cell hyperplasia or mucus secretion was observed in the IFN-γ group;the numbers of ILC2s and eosinophils were not affected by IFN-γ;the levels of IL-5 and IL-13 in the supernatants of BALF and lung homogenate, and the expression of IL-5, IL-13 and ST2 at mRNA level in lung tissues were not significantly changed by IFN-γ (P>0.05).Compared with the PBS control group, massive infiltration with inflammatory cells, excessive mucus secretion, increased numbers of ILC2s and eosinophils, up-regulated levels of IL-5 and IL-13 in the supernatants of BALF and lung homogenate, and enhanced expression of IL-5, IL-13 and ST2 at mRNA level in lung tissues were detected in the IL-33 model group (P<0.05).Compared with the IL-33 model group, the combined treatment with IL-33 and IFN-γ significantly alleviated inflammatory cell infiltration, inhibited mucus secretion, reduced the numbers of ILC2s and eosinophils, down-regulated the levels of IL-5 and IL-13 in the supernatants of BALF and lung homogenate, and suppressed the expression of IL-5, IL-13 and ST2 at mRNA in lung tissues (P<0.05).Conclusion IFN-γ can inhibit the proliferation of eosinophils and ILC2s induced by IL-33, and reduce the secretion of IL-5 and IL-13, which indicates that IFN-γ has an inhibitory effect on acute allergic airway inflammation induced by IL-33 in mice.

Objective: To systematically analyze the distribution of research hotspots related to the COVID, provide reference for future scientific research. Methods: Relevant literatures collected by PubMed database since December 1, 2019 were retrieved, the key information related to literatures was extracted and analyzed, and the wordcloud2 package of R software was used for word frequency analysis. Results: A total number of 194 valid papers were obtained, which published in 81 journals. Most papers was published in early February 2020, and a maximum of 24 papers were published in a single day. 167 papers (86.08%) were written in English. These papers included case reports, expert opinions, guidelines, articles, reviews, communications and other forms, and the subjects included epidemiology, prevention and control, virology, diagnosis and treatment, pathology and etiology, vaccines and drugs, epidemic prediction models, and bioinformatics analysis. The proportion of article in English literatures was higher than that in Chinese literatures (P=0.005). Among them, 91 papers (46.9%) were independently completed by the Chinese researchers, 15 papers (7.7%) were completed by the Chinese and foreign researchers, and 88 papers (45.4%) were completed by foreign researchers. Conclusions At present, the researches on the new coronavirus pneumonia mainly focus on virology and epidemiology, but lack of relevant research results such as treatment and prognosis.

We optimized a fluorescent quantitative polymerase chain reaction (qPCR) assay system for rapid and real time detection of SARS-CoV-2 RNA. The results show that the lowest dilution of RNA samples used for the detection of SARS-CoV-2 RNA could reach 1/10 000 (the initial value is set as 10 ng/μL). Moreover, the cycle threshold (Ct) for samples of clinically diagnosed COVID-19 was lower than 35 or 40. The sensitivity of this method was satisfactory. The results were consistent with those of the COVID-19 detection kit on the market under the same conditions, but the number of cycles required was shortened by about 2. Therefore, the optimized assay developed in this study can be used in screening and early clinical diagnosis. Our work provides a tool to facilitate rapid clinical diagnosis of COVID-19.
Betacoronavirus ; genetics ; isolation & purification ; Coronavirus Infections ; diagnosis ; virology ; Early Diagnosis ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; virology ; Polymerase Chain Reaction ; methods ; standards ; RNA, Viral ; analysis ; genetics ; Sensitivity and Specificity ; Time Factors