title: HHV-6 cell receptor CD46 expression on various cell subsets of six blood and graft sources: a prospective series.
abstract: BACKGROUND
  Cord Blood (CB) are increasingly used as an alternative stem cells source in adults for allogeneic Stem Cell Transplantation (allo-SCT). The risk of human herpesvirus (HHV-6) reactivation is significantly higher after CB transplant vs unrelated peripheral blood stem cells (PBSC) allo-SCT. Higher HHV-6 cell receptor CD46 expression on progenitor cells in CB may explain this difference.
  
  
  OBJECTIVE
  To prospectively compare the HHV-6 cell receptor CD46 expression on various cell subsets of three freshly harvested blood sources on one hand and of three graft sources on the other hand.
  
  
  METHODS
  52 samples were used for the purpose of this study. They were issued from peripheral blood (PB, n = 10), G-CSF mobilised PB (GCSF-PB, n = 10), cord blood (CB, n = 10), unmanipulated bone marrow (uBM, n = 5), leukapheresis product (LP, n = 10) and thawed CB graft (n = 7). CD46 expression was assessed by FACS analysis on total lymphocytes, monocytes, NK cells, T and B cells subsets, plasmacytoid (pDCs) dendritic cells and stem cells.
  
  
  RESULTS
  As all cell subsets were found CD46 positive, CD46 mean fluorescence intensity (MFI) was then considered for comparison between the three blood sources and the three graft sources. The most impressive result observed was that HHV-6 cell receptor CD46 expression was significantly reduced in almost all cell components of thawed CB graft compared to other graft sources.
  
  
  CONCLUSIONS
  This original study shows strong differences in term of quantitative CD46 expression between several blood and grafts samples. Our results suggest that other factors than the qualitative CD46 expression play a role in the higher HHV-6 reactivation observed after CB transplant in adults.
authors.affiliation: Service d'Hématologie Clinique, CHU Hôtel Dieu, Université de Nantes, Centre d'Investigation Clinique en Cancerologie (CI2C) and INSERM U892, Nantes, France. patrice.chevallier@chu-nantes.fr
authors.forename: Patrice
authors.initials: P
authors.lastname: Chevallier
authors.forename: Nelly
authors.initials: N
authors.lastname: Robillard
authors.forename: Marina
authors.initials: M
authors.lastname: Illiaquer
authors.forename: Julie
authors.initials: J
authors.lastname: Esbelin
authors.forename: Mohamad
authors.initials: M
authors.lastname: Mohty
authors.forename: Celine
authors.initials: C
authors.lastname: Bodin-Bressollette
authors.forename: Thierry
authors.initials: T
authors.lastname: Guillaume
authors.forename: Veronique
authors.initials: V
authors.lastname: Stocco
authors.forename: Fabienne
authors.initials: F
authors.lastname: Auffray
authors.forename: Sophie
authors.initials: S
authors.lastname: Derenne
authors.forename: Lucie
authors.initials: L
authors.lastname: Planche
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Bene
authors.forename: Berthe-Marie
authors.initials: BM
authors.lastname: Imbert-Marcille
mesh_terms: D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000166:cytology / Q000821:virology; D003713:Dendritic Cells / Q000166:cytology / Q000821:virology; D005260:Female; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015654:Herpesvirus 6, Human; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000821:virology; D008297:Male; D051916:Membrane Cofactor Protein / Q000378:metabolism*; D008875:Middle Aged; D011446:Prospective Studies; D011991:Receptors, Virus / Q000378:metabolism*; D012307:Risk Factors; D014184:Transplantation, Homologous; D014775:Virus Activation; D055815:Young Adult
chemical_list: C497857:CD46 protein, human; D051916:Membrane Cofactor Protein; D011991:Receptors, Virus