Mycoplasma gallisepticum requires ATP to activate the canonical inflammasome in vitro.

Abstract

Abstract Mycoplasma gallisepticum (MG) is a bacteria which lacks a cells wall and colonizes mucosal epithelial cells. This colonization commonly occurs in the respiratory tracts of chickens and turkeys, leading to chronic respiratory disease. MG is an economically significant pathogen in poultry and can cause large economic losses on poultry farms because of decreased egg laying. Although the importance of MG as an economically relevant pathogen is understood, there is a paucity of knowledge in regards to its pathogenesis. One possible mechanism is via the activation of the inflammasome, a multi-protein complex leading to the maturation of IL-1β and IL-18 as well as the inflammatory form of cell death called pyroptosis. Interestingly, Mycoplasma hyorhinis (MH) was shown to activate the NLRP3 inflammasome in THP-1 and mouse bone marrow derived dendritic cells (BMDCs). In addition, HD-11 cells co-cultured with tracheal epithelial cells that were exposed to MG, show increased levels of IL-1β. In this study, we aimed to determine if MG activated the inflammasome in murine and chicken macrophages. We found that MG activates the canonical inflammasome in primary murine macrophages via the induction of IL-1b release. However, we determined that this MG-mediated activation of the canonical inflammasome requires the addition of ATP in vitro. In addition, we also found that MG alone is not sufficient to activate pyroptosis in vitro. Interestingly, MG also initiated the production of IL-6 in these cells, suggesting potential activation of the NF-κB pathway. We are currently working with the HD-11 chicken cell line to determine if MG activates the inflammasome in these cells as well.