Revealing the roles of DnaA on the biological characteristics of Brucella and the inflammatory response to Brucella
Aihua, Wang (2021), Revealing the roles of DnaA on the biological characteristics of Brucella and the inflammatory response to Brucella, Dryad, Dataset, https://doi.org/10.5061/dryad.pzgmsbcj9
The Brucella cell cycle, including chromosomal replication and cell division, is coordinated with the virulence of the bacteria. DnaA, a chromosomal replication initiator protein, is an essential regulator of cell cycle progression and is tightly regulated both temporally and spatially because it is activated only once per cell cycle in bacteria. Although DnaA exists in many bacteria, the role of DnaA during Brucella infection, with the exception of its induction of the initiation of chromosome replication, remains unclear. Here, we generated a Brucella strain in which the expression of DnaA was conditionally controlled via anhydrotetracycline (ATc)-induced complementation of a deletion of the dnaA gene encoding the DnaA protein. We found that DnaA is required for Brucella division and activity to response various environmental stresses. As demonstrated by RNA-seq, DnaA was found to be involved in physiological processes, including the regulation of the cell cycle. Moreover, the inactivation of DnaA can inhibit Brucella intracellular trafficking through impaired replicative Brucella-containing vacuole (rBCV) biogenesis. In RAW 264.7 cells, the mutant strain promoted secretion of the proinflammatory cytokines interleukin 1β (IL-1β) and interleukin 6 (IL-6) and reduced survival. In addition, the inhibition of DnaA expression also attenuated the virulence of Brucella, but the resultant strain exhibited excellent immunogenicity to activate host immune responses in a mouse model. Altogether, these findings show that DnaA is involved in Brucella virulence in vitro and in vivo and could become a new target for the development of a safer and more efficient live attenuated Brucella vaccine.
All gene Expression of B. suis S2 strain in RNA-seq (three biological repetitions)
control 1.xls, control 2.xls, control 3.xls
All gene Expression of ΔDnaA strain in RNA-seq (three biological repetitions)
ΔDnaA 1.xls, ΔDnaA 2.xls, ΔDnaA 3.xls
Compared to B. suis S2 strain, the DGEs expression in ΔDnaA strain