title: Significant biochemical, biophysical and metabolic diversity in circulating human cord blood reticulocytes.
abstract: BACKGROUND
  The transition from enucleated reticulocytes to mature normocytes is marked by substantial remodeling of the erythrocytic cytoplasm and membrane. Despite conspicuous changes, most studies describe the maturing reticulocyte as a homogenous erythropoietic cell type. While reticulocyte staging based on fluorescent RNA stains such as thiazole orange have been useful in a clinical setting; these 'sub-vital' stains may confound delicate studies on reticulocyte biology and may preclude their use in heamoparasite invasion studies.
  
  
  METHODS
  Here we use highly purified populations of reticulocytes isolated from cord blood, sorted by flow cytometry into four sequential subpopulations based on transferrin receptor (CD71) expression: CD71high, CD71medium, CD71low and CD71negative. Each of these subgroups was phenotyped in terms of their, morphology, membrane antigens, biomechanical properties and metabolomic profile.
  
  
  RESULTS
  Superficially CD71high and CD71medium reticulocytes share a similar gross morphology (large and multilobular) when compared to the smaller, smooth and increasingly concave reticulocytes as seen in the in the CD71low and CD71negativesamples. However, between each of the four sample sets we observe significant decreases in shear modulus, cytoadhesive capacity, erythroid receptor expression (CD44, CD55, CD147, CD235R, and CD242) and metabolite concentrations. Interestingly increasing amounts of boric acid was found in the mature reticulocytes.
  
  
  CONCLUSIONS
  Reticulocyte maturation is a dynamic and continuous process, confounding efforts to rigidly classify them. Certainly this study does not offer an alternative classification strategy; instead we used a nondestructive sampling method to examine key phenotypic changes of in reticulocytes. Our study emphasizes a need to focus greater attention on reticulocyte biology.
authors.affiliation: Laboratory of Malaria Immunobiology, Singapore Immunology Network (SIgN), Agency for Science Technology and Research (ASTAR), Biopolis, Singapore.
authors.forename: Benoît
authors.initials: B
authors.lastname: Malleret
authors.forename: Fenggao
authors.initials: F
authors.lastname: Xu
authors.forename: Narla
authors.initials: N
authors.lastname: Mohandas
authors.forename: Rossarin
authors.initials: R
authors.lastname: Suwanarusk
authors.forename: Cindy
authors.initials: C
authors.lastname: Chu
authors.forename: Juliana A
authors.initials: JA
authors.lastname: Leite
authors.forename: Kayen
authors.initials: K
authors.lastname: Low
authors.forename: Claudia
authors.initials: C
authors.lastname: Turner
authors.forename: Kanlaya
authors.initials: K
authors.lastname: Sriprawat
authors.forename: Rou
authors.initials: R
authors.lastname: Zhang
authors.forename: Olivier
authors.initials: O
authors.lastname: Bertrand
authors.forename: Yves
authors.initials: Y
authors.lastname: Colin
authors.forename: Fabio T M
authors.initials: FT
authors.lastname: Costa
authors.forename: Choon Nam
authors.initials: CN
authors.lastname: Ong
authors.forename: Mah Lee
authors.initials: ML
authors.lastname: Ng
authors.forename: Chwee Teck
authors.initials: CT
authors.lastname: Lim
authors.forename: Francois
authors.initials: F
authors.lastname: Nosten
authors.forename: Laurent
authors.initials: L
authors.lastname: Rénia
authors.forename: Bruce
authors.initials: B
authors.lastname: Russell
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D005312:Fetal Blood / Q000166:cytology* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D012156:Reticulocytes / Q000166:cytology* / Q000378:metabolism
chemical_list: D015703:Antigens, CD