AIM: To investigate the feasibility and infection efficiency of MSCs as the target cells of gene delivery mediated by adenoviral vector carrying CTLA4Ig gene, and to study the mechanism of transgenic MSC to inhibit immune response ex vivo. METHODS: The recombinant adenovirus containing CTLA4Ig gene was constructed, by which rat MSCs with various multiplicity of infection (MOI) were conducted. The infection efficiency was analyzed with FACS and fluorescence microscope. The expression of CTLA4Ig protein in transgenic MSCs was detected by FACS and western blot. Co-culturing the transgenic MSCs with mixed lymphocytes, the inhibitory effect of transgenic MSCs on lymphocyte proliferation was also observed. RESULTS: The adenoviral vector delivered CTLA4Ig gene with high efficiency to MSCs. The expression of CTLA4Ig protein was detected in transgenic MSCs. The gene modified MSCs inhibited the proliferation of mixed lymphocytes and maximal inhibition rate was observed on day 4 of MLR. The inhibition induced by CTLA4Ig was donor-specific. CONCLUSION: MSCs is a promising target cell for gene delivery. The expressed CTLA4Ig specifically inhibits the lymphocyte proliferation ex vivo.

Objective:To analyze Helicobacter pylori ( Hp) resistance in Xiaoshan area from 2013 to 2020 and to provide reference for the selection of clinical antibiotics for the eradication of Hp in this area. Methods:Non-repetitive Hp strains isolated from patients treated in the First People′s Hospital of Xiaoshan District, Hangzhou from January 2013 to December 2020 and the drug susceptibility test results of these strains were collected. The patients were grouped by every 10 years of age to analyze the drug resistance of Hp in different groups and its changing trends. Results:A total of 54 912 Hp strains were isolated and cultured. The resistance rates of Hp isolates to amoxicillin, metronidazole, clarithromycin and levofloxacin were 0.42%, 92.94%, 22.41% and 29.83%, respectively. The drug resistance rates to clarithromycin and levofloxacin were increasing year by year. The resistance rates to levofloxacin, clarithromycin and metronidazole increased with age. The resistance rates to clarithromycin, levofloxacin and metronidazole in women were higher than those in men, especially in the 21-60 age group. The resistance rate to clarithromycin was significantly higher in people under 20 years old. In 2017 to 2019, the resistance rate to amoxicillin was higher in people under 20 years old than in other age groups. In 2020, the resistance rates to levofloxacin and clarithromycin in people over 70 years old both exceed 57% and increased rapidly. Conclusions:The resistance rates of Hp to levofloxacin, clarithromycin and metronidazole in Xiaoshan area were all at a high level. It was recommended to use individualized treatments for the eradication of Hp. In addition, attention should be paid to the young and older people.