Proteomic characterization of pleural effusion, a specific host niche of Mycoplasma mycoides subsp mycoides from cattle with contagious bovine pleuropneumonia (CBPP)

摘要

Mycoplasma mycoides subsp. mycoides (Mmm) is the causative agent of contagious bovine pleuropneumonia (CBPP), a severe pleuropneumonia in cattle. The abnormal accumulation of pleural fluid, called pleural effusion (PE), is one of the characteristics of this disease. We performed a proteomic analysis of seven PE samples from experimentally infected cattle and characterized their composition with respect to bovine and Mmm proteins. We detected a total of 963 different bovine proteins. Further analysis indicated a strong enrichment of proteins involved in antigen processing, platelet activation and degranulation and apoptosis and an increased abundance of acute phase proteins. With regard to the pathogen, up to 10(8) viable mycoplasma cells per ml were detected in the PE supernatant. The proteomic analysis revealed 350 mycoplasma proteins, including proteins involved in virulence-associated processes like hydrogen peroxide (H2O2) production and capsule synthesis. The bovine proteins detected will aid to characterize the inflammasome during an acute pleuropneumonia in cattle and the identified mycoplasma proteins will serve as baseline data to be compared with in vitro studies to improve our understanding of pathogenicity mechanisms. Based on our results, we named the pleural effusion an "in vivo niche" of Mmm during the acute phase of CBPP.