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oai:figshare.com:article/31451194 2025-12-01T00:00:00Z portal_693 item_type_8 month_year_12_2025

Rgg2/Rgg3 Quorum Sensing in Streptococcus pyogenes and Innate Immune Cell Responses Ian McIntire (23291419) Streptococcus pyogenes Innate immune responses Nitric oxide Quorum sensing Rgg2/Rgg3 Iron Starvation The immune system and microbial pathogens work against each other in many ways resulting in a never-ending dance. This thesis investigates the relationship between macrophages, a type of innate immune cell, and Streptococcus pyogenes, an important human pathogen. In Chapter 2 of this thesis, it is shown that physiologically relevant concentrations of nitric oxide generates dinitrosyliron complexes which deplete the available intracellular iron in S. pyogenes and induces iron starvation. These results give more context to the functions of dinitrosyliron complexes in biological systems which previously were poorly understood. In Chapter 3 of this thesis, it is shown how S. pyogenes suppresses pro-inflammatory responses of macrophages. Reactive oxygen and reactive nitrogen species production, chemokine production, and neutrophil recruitment are all suppressed. Expression of the Rgg2/Rgg3 quorum sensing system allows S. pyogenes to suppress these innate immune responses. Altogether, the results from these chapters explores how the immune system and microbial pathogens interact with each other to try and come out on top. 2025-12-01T00:00:00Z Text Thesis 10.25417/uic.31451194.v1 https://figshare.com/articles/thesis/Rgg2_Rgg3_Quorum_Sensing_in_Streptococcus_pyogenes_and_Innate_Immune_Cell_Responses/31451194 In Copyright