To simplify the preparation of neuraminidase in screening influenza neuraminidase inhibitors,the neuraminidase gene of H5N1 influenza A virus was optimized for high expression in mammalian cells and cloned into pcDNA4/TO vector. The recombinant plasmids were transfected into T-REx 293 cells to establish stable cell lines,in which the expression of neuraminidase was induced by tetracycline. Unlike from virions,the preparation of neuraminidase became conveniently and safely from these stable cell lines,which would facilitate developing high throughput assay to screen neuraminidase inhibitors. More than 3000 natural extracts and herbal components were screened in the study. Baicalin and baicalein were found to inhibit oseltamivir-sensitive and oseltamivir-resistant neuraminidase at similar level,furthermore,their anti-influenza activity was confirmed by plaque assay and virus inhibition assay.

The need for an efficacious HIV/AIDS vaccine remains the highest priority of the world HIV/AIDS agenda. The generation of an efficacious HIV/AIDS vaccine proves an enormous scientific challenge. This article reviews the neutralizing antibody problem, elusive immune protection, immunogen design, pre-existing anti-vector immunity and design of phase 3 vaccine trials and the challenges and opportunities in development of HIV/AIDS vaccine are discussed.

The outbreaks caused by coronavirus (CoV) infections including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and COVID-19 have emerged in recent years, posing a continued threat to public health. Highly pathogenic CoV infections usually induce a series of immune responses, including innate immunity, humoral immunity, cellular immunity and mucosal immunity. These responses not only are critical to suppressing and eliminating the invasion of viruses, but also play an important role in immunopathological changes and disease progression. A deep understanding of the dual roles of immune responses will help to elucidate the pathogenic mechanism of CoV and maintain the balance between immune protection and immunopathology, which will be conducive to the research and development of safe and effective CoV vaccines. This review summarized the dual roles of immune responses in highly pathogenic CoV infections and discussed the implications for the research and development of novel CoV vaccines.

Objective:To investigate the clinical characteristics of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and corona virus disease 2019 (COVID-19) infection.Methods:Clinical data of AECOPD patients over 65 years old who were diagnosed in the Respiratory and Emergency Departments of the Dongzhimen Hospital, Beijing University of Chinese Medicine from September 2022 to September 2023 were collected. AECOPD patients were divided into a COVID-19 group ( n=29) and a non COVID-19 group ( n=31). The platelet count, white blood cell count, lymphocyte count, neutrophil count, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), C-reactive protein (CRP), procalcitonin (PCT), partial pressure of oxygen (PO 2), partial pressure of carbon dioxide (PCO 2), D-dimer (D-D), and interleukin-6 (IL-6) were compared between two groups of patients upon admission Confusion, Uremia, Respiratory, BP, Age 65 Years (CURB-65) was used to compare length of hospital stay, AECOPD grading, and mortality endpoint days. Results:There was no statistically significant difference in platelet count, white blood cell count, lymphocyte count, neutrophil count, NLR, and PLR between the COVID-19 group and the non COVID-19 group (all P>0.05). The proportion of males, CRP, PCO 2, D-D, IL-6, and CURB-65 scores in the COVID-19 group were higher than those in the non COVID-19 group, while PCT and PO 2 were lower than those in the non COVID-19 group, with statistically significant difference (all P<0.05). The proportion of AECOPD grade Ⅲ in the COVID-19 group was significantly higher than that in the non COVID-19 group, and the progression rate of the disease was higher in the COVID-19 group (37.9% vs 22.6%, P<0.05). COVID-19 was an independent influencing factor for the progression of AECOPD. Conclusions:Patients over 65 years old with AECOPD infected with COVID-19 have a more pronounced inflammatory response, and CRP, IL-6, and CURB-65 scores can be used as indicators to evaluate the degree of inflammation. AECOPD infected with COVID-19 are more prone to coagulation disorders, hypoxemia, more severe illness, and easier progression, suggesting that COVID-19 infection is an independent influencing factor for the progression of AECOPD.