Related Experiment Video
Updated: Jun 14, 2026
Isolation of Murine Peritoneal Macrophages to Carry Out Gene Expression Analysis Upon Toll-like Receptors Stimulation
Published on: April 29, 2015
Protein expression changes induced in murine peritoneal macrophages by Group B Streptococcus
Federica Susta1, Davide Chiasserini, Katia Fettucciari
1Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy.
Abstract:
Protein expression changes induced in thioglycolate-elicited peritoneal murine macrophages (M Phi) by infection with type III Group B Streptococcus (GBS) are described. Proteins from control M Phi and M Phi incubated 2 h with live or heat-inactivated GBS were separated by 2-DE. Proteins whose expression was significantly different in infected M Phi, as compared with control cells, were identified by MS/MS analysis. Changes in the expression level of proteins involved in both positive and negative modulation of phagocytic functions, stress response and cell death were induced in M Phi by GBS infection. In particular, expression of enzymes playing a key role in production of reactive oxygen species was lowered in GBS-infected M Phi. Significant alterations in the expression of some metabolic enzymes were also observed, most of the glycolytic and of the pentose-cycle enzymes being down-regulated in M Phi infected with live GBS. Finally, evidence was obtained that GBS infection affects the expression of enzymes or enzyme subunits involved in ATP synthesis and in adenine nucleotides interconversion processes.
Insights
Group B Streptococcus (GBS) infection alters protein expression in murine macrophages, impacting phagocytosis, stress responses, and energy metabolism. Key enzymes for reactive oxygen species and glycolysis were notably downregulated.
Area of Science:
- Immunology
- Microbiology
- Proteomics
Background:
- Murine macrophages are crucial in host defense against bacterial infections.
- Group B Streptococcus (GBS) is a significant pathogen, particularly in neonates.
- Understanding host-pathogen interactions at the protein level is vital for developing therapeutic strategies.
Purpose of the Study:
- To investigate the proteomic changes in murine macrophages upon infection with GBS.
- To identify specific proteins and pathways affected by GBS, particularly those related to immune function and metabolism.
Main Methods:
- Thioglycolate-elicited peritoneal murine macrophages were infected with live or heat-inactivated GBS.
- Proteins were separated using two-dimensional gel electrophoresis (2-DE).
- Differentially expressed proteins were identified using tandem mass spectrometry (MS/MS analysis).
Main Results:
- GBS infection significantly altered the expression of proteins involved in phagocytic modulation, stress response, and cell death.
- Expression of enzymes critical for reactive oxygen species production was decreased in infected macrophages.
- Metabolic enzymes, including glycolytic and pentose-cycle enzymes, were predominantly downregulated in macrophages infected with live GBS.
- GBS infection impacted the expression of enzymes involved in ATP synthesis and adenine nucleotide metabolism.
Conclusions:
- GBS infection induces complex proteomic alterations in macrophages, affecting critical cellular functions.
- The downregulation of key metabolic and reactive oxygen species-producing enzymes suggests a mechanism by which GBS evades host defenses.
- These findings provide insights into macrophage dysfunction during GBS infection and potential therapeutic targets.
