TY - JOUR T1 - Late Breaking Abstract - Enhanced expression of IL-1ß in later stage of influenza A virus infection is independent of NLRP3 in vitro JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.2741 VL - 56 IS - suppl 64 SP - 2741 AU - Yunfeng Shi AU - Xiaohan Shi AU - Jingjing Liang AU - Jinmei Luo AU - Junhui Ba AU - Benquan Wu Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/2741.abstract N2 - Background and Aims: Influenza A virus (IAV) is the major cause of severe viral pneumonia. The NLRP3 inflammasome in macrophages has been found essential for responsing against IAV infection. The pathology and immunity in IAV infection are self-limited to within one week commonly. Meanwhile, researches found that inflammation induced by NLRP3 inflammasome in the early and later stage of IAV infection was under debate. This study aims to investigate the detailed activity and role of NLRP3 inflammasome during IAV infection in vitro.Methods: After mouse macrophages were cultured and infected with IAV H1N1 for 6 hours (6h group) and one week (1w group) respectively, RT-qPCR was applied to detect the transcription of NLRP3, caspase-1 and IL-1β, western blot was used to detect the protein of NLRP3, caspase-1 and cleaved caspase-1, protein of NLRP3 in cells was also observed by immunofluorescent staining, and the concentration of IL-1β in supernatant was measured by ELISA.Results: In 6h group, the expression of NLRP3, caspase-1, cleaved caspase-1, IL-1β were increased compared with those of blank group (all P<0.05). The data showed the expression of NLRP3, caspase-1 and IL-1β diverged in IAV infected macrophages at one week after infection. In 1w group, expression of NLRP3 decreased, while expression of caspase-1, cleaved caspase-1 and IL-1β increased sequentially, compared with 6h group (all P<0.05).Conclusion: These findings confirmed that IAV infection activated NLRP3 inflammasome, and the divergent expression of NLRP3 from caspase-1 and IL-1β in 1w group suggested that the transcription and secretion of IL-1β was independent of NLRP3 in the later stage of IAV infection.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 2741.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -