Comprehensive proteome analysis reveals the central role of macrophage lysosomes in regulating immune responses

ABSTRACT: Phagocytosis and autophagy in macrophages have been shown to be essential to both innate and adaptive immunity. Lysosomes are the main catabolic subcellular organelles responsible for degradation and recycling of both extracellular and intracellular material, which are the final steps in phagocytosis and autophagy. Lysosomes are critical for the correct function of macrophages; however, the molecular mechanisms underlying lysosomal functions after infection remain to be fully clarified. In this study, we conducted a quantitative proteomics analysis of the changes in constitution and glycosylation of proteins in lysosomes derived from murine RAW 264.7 macrophage cells treated with different types of pathogens comprising examples of bacteria (Listeria monocytogenes, L. m), DNA viruses (Herpes simplex virus type-1, HSV-1) and RNA viruses (vesicular stomatitis virus, VSV). In total, 3,704 lysosome-related proteins and 264 glycosylated proteins were identified. Bioinformatic analysis showed lysosomes initiated distinct pathways according to the type of pathogens and function via integrated signaling of the innate and adaptive immune systems. Fluctuations in the glycosylation of several lysosomal proteins were also determined. Immunofluorescence assays showed that autophagy was increased following infection with all three types of pathogens, while only L. m infection stimulated lysosomal biosynthesis. Combined with more detailed immunoblotting and immunofluorescence analyses, these results suggest that macrophage lysosomes function as a signaling center in regulating immune responses to microbial infection.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Macrophage

SUBMITTER: Wei Ge  

LAB HEAD: wei.ge

PROVIDER: PXD002915 | Pride | 2017-04-24

REPOSITORIES: Pride