# A quorum-sensing-regulated protein controls cell surface alteration in S. pyogenes

> **NIH NIH F30** · UNIVERSITY OF ILLINOIS AT CHICAGO · 2021 · $44,577

## Abstract

PROJECT SUMMARY
Streptococcus pyogenes, also known as Group A Streptococcus (GAS), is a gram-positive pathogen that, in its
virulent state, is responsible for a variety of human diseases ranging from acute pharyngitis, impetigo, scarlet
fever, and necrotizing fasciitis. In addition to its contribution to these disease states, the bacterium is also
asymptomatically colonizing up to 35% the population, and this colonization state remains its major reservoir for
survival. Our group has characterized a novel quorum sensing system in S. pyogenes termed the Rgg2/3
pathway which consists of two transcriptional regulators, an activator (Rgg2) and a repressor (Rgg3) that are
modulated by two short hydrophobic peptide signals (SHPs). The Rgg 2/3 circuit regulates a small secreted
protein, Stc, that induces increased biofilm formation and enhanced lysozyme resistance. Both of these
phenotypes are indicative of alterations to the cell surface of the bacterium, and we have recently shown that
the positively-charged Stc protein is secreted to the cell surface where it associates with surface moieties and
makes the surface more positively charged. This proposal seeks to confirm the surface moieties with which Stc
associates, and determine whether or not they are obscurred from detection by the host by Stc’s presence. We
have preliminary data showing that Stc expression leads to decreased activation of NFκB, which leads us to
believe the Stc-expressing bacteria will have a colonization advantage. A murine model of intranasal colonization
will be carried out to confirm this colonization advantage as well as examine the NFκB response in vivo. Success
of this project work will allow us to explore use of already identified therapeutics that disrupt Rgg2/3 QS in order
to eliminate bacteria in a colonizing state.

## Key facts

- **NIH application ID:** 10212951
- **Project number:** 5F30AI136359-04
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT CHICAGO
- **Principal Investigator:** Artemis Gogos
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $44,577
- **Award type:** 5
- **Project period:** 2018-08-16 → 2022-05-15

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10212951

## Citation

> US National Institutes of Health, RePORTER application 10212951, A quorum-sensing-regulated protein controls cell surface alteration in S. pyogenes (5F30AI136359-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10212951. Licensed CC0.

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