RT Journal Article SR Electronic T1 Human dental pulp stem cells: a sanctuary for relapsing Bartonella quintana JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.05.13.094037 DO 10.1101/2020.05.13.094037 A1 Hamadou Oumarou Hama A1 Attoumani Hamada A1 Gérard Aboudharam A1 Éric Ghigo A1 Michel Drancourt YR 2020 UL http://biorxiv.org/content/early/2020/05/13/2020.05.13.094037.abstract AB Bartonella quintana is a facultative intracellular bacterium responsible for relapsing fever, an example of non-sterilizing immunity. The cellular sanctuary of B. quintana in-between febrile relapses remains unknown but repeated detection of B. quintana in dental pulp specimens suggested long-term half-life dental pulp stem cells (DPSCs) as candidates. As the capacity of DPSCs to internalize microscopic particles was unknown, we confirmed that DPSCs internalized B. quintana bacteria: Gimenez staining and fluorescence microscopy localized B. quintana bacteria inside DPSCs and this internalization did not affect the cellular multiplication of DPSCs during a one-month follow-up despite the increase in the bacterial load. B. quintana-infected DPSCs did not produce Tumor Necrosis Factor-α whereas an important production of Monocytes Chemoattractant Protein-1 was observed. These unprecedented observations suggested the possibility that DPSCs were shelters for the long-term persistence of B. quintana in the host, warranting further experimental and clinical investigations.