# Elucidating Rgg-mediated quorum sensing networks in Streptococcus pneumoniae and their contributions in pathogenesis

> **NIH NIH F31** · UNIVERSITY OF ILLINOIS AT CHICAGO · 2020 · $20,207

## Abstract

Abstract
Quorum Sensing (QS), or bacterial communication by intercellular chemical signaling, is a process common to many (if
not most) bacterial species; yet, it is unclear how QS signaling pathways contribute to virulence in many clinically
significant pathogens. The Federle lab has helped to characterize a family of transcriptional regulators, known as Rgg
proteins, as mediators of QS. We and others have shown the importance of Rgg proteins in multiple species of
streptococci in regulating expression of genes that may enhance their ability to colonize and infect the host. Rgg proteins
are known to regulate genes important for 1) controlling virulence; 2) promoting the development of resistance to
lysozyme, a host-produced antimicrobial enzyme; 3) stimulating the formation of biofilms, or protective bacterial
communities; 4) initiating the development of natural competence to take up DNA from the environment; and 5)
promoting the ability to adhere to epithelial cells. The role of the Rgg proteins in the pathogenic lifestyle of the clinically
significant pathogen S. pneumoniae has yet to be investigated, but published genome-level mutagenesis studies indicate
Rgg proteins in this organism are critical in in vivo animal models of infection. We have constructed isogenic mutants for
each Rgg protein important in vivo and have performed transcriptomic analysis to identify gene targets under Rgg-
regulation. Our analysis has revealed 18 gene targets under regulation by the Rgg protein SP_0141 in the pneumococcal
encapsulated strain TIGR4 (serotype 4). We are in the process of testing gene targets of interest in order to understand
Rgg-mediated QS and its role in virulence. We will then explore the consequences of using QS to regulate mechanisms of
pathogenesis in the presence of immune surveillance. Understanding the molecular networks under QS regulation and the
advantage of using QS in the host will provide support for the possibility of modulating QS as an effective strategy for
combatting pathogens.

## Key facts

- **NIH application ID:** 9903202
- **Project number:** 5F31AI134010-03
- **Recipient organization:** UNIVERSITY OF ILLINOIS AT CHICAGO
- **Principal Investigator:** Kayleigh Tovar
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $20,207
- **Award type:** 5
- **Project period:** 2018-05-16 → 2020-11-15

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9903202

## Citation

> US National Institutes of Health, RePORTER application 9903202, Elucidating Rgg-mediated quorum sensing networks in Streptococcus pneumoniae and their contributions in pathogenesis (5F31AI134010-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9903202. Licensed CC0.

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