Cyclic di-GMP regulates type three secretion system and virulence in Bordetella bronchiseptica

GUTIÉRREZ, MARÍA DE LA PAZ; WONG, TING; DAMRON, FREDERICK HEATH; FERNANDEZ, JULIETA (CORR. AUTHOR); SISTI, FEDERICO (CORR. AUTHOR)

INFECTION AND IMMUNITY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2022

0019-9567

The second messenger c-di-GMP is a ubiquitous molecule in bacteria that regulates diverse phenotypes. Among them, motility and biofilm formation are the most studied. Furthermore, c-di-GMP has been suggested to regulate virulence factors, therefore making it important for pathogenesis.Previously we described that c-di-GMP regulates biofilm formation and swimming motility in Bordetella bronchiseptica. Here we present a multi-omic approach on B. bronchiseptica strains expressing different cytoplasmic c-di-GMP levels, including RNA-seq and shotgun proteomics with label-free quantification.We detected 64 proteins significantly up- or down-regulated in either low or high c-di-GMP levels and 358 genes differentially expressed between high c-di-GMP levels and the wild type strain. Among them we found stress-related proteins, nitrogen metabolism enzymes, phage-related genes and virulence factors. Interestingly, we observed that a virulence factor like the type three secretion system (TTSS) was regulated by c-di-GMP. B. bronchiseptica with high c-di-GMP levels showed significantly lower levels of TTSS components like Bsp22, BopN and Bcr4. These findings were confirmed by independent methods as q-RT PCR and western blot. Higher intracellular levels of c-di-GMP correlated with impaired capacity to induce cytotoxicity in a eukaryotic cell in vitro and with attenuated virulence in a murine model. This work presents data that will support the role that the second messenger c-di-GMP plays in the pathogenesis of Bordetellae.