title: Ex vivo virotherapy with myxoma virus does not impair hematopoietic stem and progenitor cells.
abstract: BACKGROUND
  Relapsing disease is a major challenge after hematopoietic cell transplantation for hematological malignancies. Myxoma virus (MYXV) is an oncolytic virus that can target and eliminate contaminating cancer cells from auto-transplant grafts. The aims of this study were to examine the impact of MYXV on normal hematopoietic stem and progenitor cells and define the optimal treatment conditions for ex vivo virotherapy.
  
  
  METHODS
  Bone marrow (BM) and mobilized peripheral blood stem cells (mPBSCs) from patients with hematologic malignancies were treated with MYXV at various time, temperature and incubation media conditions. Treated BM cells from healthy normal donors were evaluated using flow cytometry for MYXV infection, long-term culture-initiating cell (LTC-IC) assay and colony-forming cell (CFC) assay.
  
  
  RESULTS
  MYXV initiated infection in up to 45% of antigen-presenting monocytes, B cells and natural killer cells; however, these infections were uniformly aborted in >95% of all cells. Fresh graft sources showed higher levels of MYXV infection initiation than cryopreserved specimens, but in all cases less than 10% of CD34(+) cells could be infected after ex vivo MYXV treatment. MYXV did not impair LTC-IC colony numbers compared with mock treatment. CFC colony types and numbers were also not impaired by MYXV treatment. MYXV incubation time, temperature or culture media did not significantly change the percentage of infected cells, LTC-IC colony formation or CFC colony formation.
  
  
  CONCLUSIONS
  Human hematopoietic cells are non-permissive for MYXV. Human hematopoietic stem and progenitor cells were not infected and thus unaffected by MYXV ex vivo treatment.
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Nancy Y
authors: NY
authors: Villa
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Swarna
authors: S
authors: Bais
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Winnie M
authors: WM
authors: Chan
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Amy M
authors: AM
authors: Meacham
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Elizabeth
authors: E
authors: Wise
authors: Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Masmudur M
authors: MM
authors: Rahman
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Jan S
authors: JS
authors: Moreb
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Emma H
authors: EH
authors: Rosenau
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: John R
authors: JR
authors: Wingard
authors: Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, Florida, USA.
authors: Grant
authors: G
authors: McFadden
authors: Division of Hematology & Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA. Electronic address: christopher.cogle@medicine.ufl.edu.
authors: Christopher R
authors: CR
authors: Cogle
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism; D064592:Autografts / Q000592:standards; D001853:Bone Marrow / Q000473:pathology; D001854:Bone Marrow Cells / Q000473:pathology; D018929:Cell Culture Techniques / Q000379:methods*; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured; D005260:Female; D019337:Hematologic Neoplasms / Q000473:pathology*; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods / Q000592:standards; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000502:physiology; D006801:Humans; D008297:Male; D009233:Myxoma virus / Q000502:physiology*; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000517:prevention & control; D050130:Oncolytic Virotherapy / Q000379:methods*; D019172:Transplantation Conditioning / Q000379:methods
chemical_list: D018952:Antigens, CD34
keywords: bone marrow; mobilized peripheral stem cell blood; myxoma virus; purging; virotherapy