title: Mesenchymal stem cells promote leukaemic cells aberrant phenotype from B-cell acute lymphoblastic leukaemia.
abstract: OBJECTIVE
  The role of bone marrow-mesenchymal stem cells (BM-MSC) in leukaemic cell control is controversial. The purpose of this work was to evaluate BM-MSC role regarding the viability, proliferation and immunophenotype of normal B-cell precursors from control (Ct) patients and leukaemic cells from B-acute lymphoblastic leukaemia (B-ALL) patients.
  
  
  METHODS
  BM-MSC were isolated and characterised from voluntary donors. Mononuclear cells isolated from Ct and B-ALL bone marrow samples were cultured in the presence or absence of BM-MSC for 7days. Cell viability was determined with LIVE/DEAD and proliferation index evaluated by CFSE labelling. Cell population immunophenotypes were characterised by estimating CD19, CD10, CD20 and CD45 antigens by flow cytometry.
  
  
  RESULTS
  After co-culture, B-ALL cells exhibited higher viability (20-40%) as compared to just cells (3-10%). Ct and B-ALL absolute cell counts were higher in the presence of BM-MSC (Ct: 25/mm(3)cf8/mm(3), B-ALL: 15/mm(3)cf3/mm(3)). Normal B-cell subpopulations in co-culture had increased expression of CD19 and CD10 (Pre-pre B) and CD45 and CD20 antigens (Pre-B). B-ALL cells co-cultured with BM-MSC showed an increase in CD19 and CD20, although the greatest increase was observed in the CD10 antigen.
  
  
  CONCLUSIONS
  Lymphoid cell maintenance, at early stages of differentiation, was significantly promoted by BM-MSC in normal and leukaemic cells. Co-cultures also modulated the expression of antigens associated with the B-ALL asynchronous phenotype as CD10 co-expressed with CD19 and CD20. To our knowledge, this is the first time that CD10, CD19 and CD20 leukaemic antigens have been reported as being regulated by BM-MSC.
authors.affiliation: Grupo de Inmunobiología y Biología Celular, Facultad de Ciencias, Pontificia Universidad Javeriana, Cra 7(a), No. 40-62, Bogotá D.C., Colombia.
authors.forename: Viviana M
authors.initials: VM
authors.lastname: Rodríguez-Pardo
authors.forename: José A
authors.initials: JA
authors.lastname: Aristizabal
authors.forename: Diana
authors.initials: D
authors.lastname: Jaimes
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Quijano
authors.forename: Iliana
authors.initials: I
authors.lastname: de los Reyes
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Herrera
authors.forename: Julio
authors.initials: J
authors.lastname: Solano
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Vernot
mesh_terms: D001402:B-Lymphocytes / Q000473:pathology*; D001854:Bone Marrow Cells / Q000473:pathology; D016022:Case-Control Studies; D049109:Cell Proliferation; D048430:Cell Shape; D002470:Cell Survival; D016000:Cluster Analysis; D018920:Coculture Techniques; D006801:Humans; D016130:Immunophenotyping; D018655:Lymphocyte Count; D059630:Mesenchymal Stem Cells / Q000473:pathology*; D039902:Multipotent Stem Cells / Q000473:pathology; D010641:Phenotype; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000276:immunology / Q000473:pathology*