title: Reprogramming diminishes retention of Mycobacterium leprae in Schwann cells and elevates bacterial transfer property to fibroblasts.
abstract: BACKGROUND
  Bacterial pathogens can manipulate or subvert host tissue cells to their advantage at different stages during infection, from initial colonization in primary host niches to dissemination. Recently, we have shown that Mycobacterium leprae (ML), the causative agent of human leprosy, reprogrammed its preferred host niche de-differentiated adult Schwann cells to progenitor/stem cell-like cells (pSLC) which appear to facilitate bacterial spread. Here, we studied how this cell fate change influences bacterial retention and transfer properties of Schwann cells before and after reprogramming.
  
  
  RESULTS
  Using primary fibroblasts as bacterial recipient cells, we showed that non-reprogrammed Schwann cells, which preserve all Schwann cell lineage and differentiation markers, possess high bacterial retention capacity when co-cultured with skin fibroblasts; Schwann cells failed to transfer bacteria to fibroblasts at higher numbers even after co-culture for 5 days. In contrast, pSLCs, which are derived from the same Schwann cells but have lost Schwann cell lineage markers due to reprogramming, efficiently transferred bacteria to fibroblasts within 24 hours.
  
  
  CONCLUSIONS
  ML-induced reprogramming converts lineage-committed Schwann cells with high bacterial retention capacity to a cell type with pSLC stage with effective bacterial transfer properties. We propose that such changes in cellular properties may be associated with the initial intracellular colonization, which requires long-term bacterial retention within Schwann cells, in order to spread the infection to other tissues, which entails efficient bacterial transfer capacity to cells like fibroblasts which are abundant in many tissues, thereby potentially maximizing bacterial dissemination. These data also suggest how pathogens could take advantage of multiple facets of host cell reprogramming according to their needs during infection.
authors.affiliation: MRC Center for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK ; Center for Neuroregeneration, University of Edinburgh, Edinburgh, EH16 4UU, UK ; Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, 10065, USA.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Masaki
authors.affiliation: MRC Center for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK.
authors.forename: Aidan
authors.initials: A
authors.lastname: McGlinchey
authors.affiliation: MRC Center for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Tomlinson
authors.affiliation: Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, 10065, USA.
authors.forename: Jinrong
authors.initials: J
authors.lastname: Qu
authors.affiliation: MRC Center for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4UU, UK ; Center for Neuroregeneration, University of Edinburgh, Edinburgh, EH16 4UU, UK ; Center for Infectious Diseases, University of Edinburgh, Edinburgh, EH16 4UU, UK ; Laboratory of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, 10065, USA.
authors.forename: Anura
authors.initials: A
authors.lastname: Rambukkana