New roles for glutathione: Modulators of bacterial virulence and pathogenesis

Abstract

Low molecular weight (LMW) thiols contain reducing sulfhydryl groups that are important for maintaining antioxidant defense in the cell. Aside from the traditional roles of LMW thiols as redox regulators in bacteria, glutathione (GSH) has been reported to affect virulence and bacterial pathogenesis. The role of GSH in virulence is diverse, including the activation of virulence gene expression and contributing to optimal biofilm formation. GSH can also be converted to hydrogen sulfide (H 2 S) which is important for the pathogenesis of certain bacteria. Besides GSH, some bacteria produce other LMW thiols such as mycothiol and bacillithiol that affect bacterial virulence. We discuss these newer reported functions of LMW thiols modulating bacterial pathogenesis either directly or indirectly and via modulation of the host immune system.

Streptococcus pyogenes Hijacks Host Glutathione for Growth and Innate Immune Evasion

“…Host glutathione can act as a spatiotemporal cue for some intracellular pathogens to switch on virulence gene circuits at the right time and environmental niche ( 29 – 34 ), prompting us to investigate whether GAS can also utilize host acquired glutathione as a signal to regulate virulence circuits. We examined global gene expression patterns in wild-type HKU16 and HKU16Δ gshT grown in THY to late logarithmic growth phase using transcriptome sequencing (RNA-seq).…”

A sulfide-sensor and a sulfane sulfur-sensor collectively regulate sulfur-oxidation for feather degradation by Bacillus licheniformis

“…H 2 S is oxidized by SQR to sulfane sulfur, and sulfane sulfur is reduced by cellular thiols to form H 2 S and oxidized thiols 54 , 55 . B. licheniformis MW3 uses bacillithiol as its main intracellular low-molecular-weight thiol 56 , and it has similar chemical properties as GSH 57 . Hence, sulfide could be produced by oxidizing bacillithiol if sulfane sulfur accumulates in cells.…”

Thiol-Disulfide Homeostasis in Skin Diseases

“…HPV helps infected cells adapt to a pro-oxidant microenvironment [ 21 ]. Low molecular weight thiols have many functions in the human body, including antioxidant defense, cell signaling and modulation of the immune response [ 151 ]. HPV virions are made up of capsid proteins L1 and L2 which have free thiols in their structure.…”