G1-arrested newborn cells are the predominant infectious form of the pathogen Brucella abortus.

TitleG1-arrested newborn cells are the predominant infectious form of the pathogen Brucella abortus.
Publication TypeJournal Article
Year of Publication2014
AuthorsDeghelt, M., C. Mullier, J-F. Sternon, N. Francis, G. Laloux, D. Dotreppe, C. Van der Henst, C. Jacobs-Wagner, J-J. Letesson, and X. De Bolle
JournalNat Commun
Date Published2014 Jul 09
KeywordsBrucella abortus, Brucellosis, Cells, Cultured, Chromosomes, Bacterial, DNA Replication, DNA, Bacterial, G1 Phase Cell Cycle Checkpoints, HeLa Cells, Humans, Vacuoles

Several intracellular pathogens, such as Brucella abortus, display a biphasic infection process starting with a non-proliferative stage of unclear nature. Here, we study the cell cycle of B. abortus at the single-cell level, in culture and during infection of HeLa cells and macrophages. The localization of segregation and replication loci of the two bacterial chromosomes indicates that, immediately after being engulfed by host-cell endocytic vacuoles, most bacterial cells are newborn. These bacterial cells do not initiate DNA replication for the next 4 to 6 h, indicating a G1 arrest. Moreover, growth is completely stopped during that time, reflecting a global cell cycle block. Growth and DNA replication resume later, although bacteria still reside within endosomal-like compartments. We hypothesize that the predominance of G1-arrested bacteria in the infectious population, and the bacterial cell cycle arrest following internalization, may constitute a widespread strategy among intracellular pathogens to colonize new proliferation niches.

Alternate JournalNat Commun
PubMed ID25006695
PubMed Central IDPMC4104442
Grant ListR01 GM065835 / GM / NIGMS NIH HHS / United States
GM065835 / GM / NIGMS NIH HHS / United States
/ / Howard Hughes Medical Institute / United States
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