title: Purification of human tonsil plasma cells: pre-enrichment step by immunomagnetic selection of CD31(+) cells.
abstract: BACKGROUND
  The advancement of knowledge about the biology of human normal plasma cells (PC) is hampered by their low frequency and difficult isolation. The aim of this study is to design a way of purifying these cells.
  
  
  METHODS
  To this end, advantage was taken of the fact that human tonsil PC expressed surface CD31 at higher levels than the rest of tonsil B cells.
  
  
  RESULTS
  The immunomagnetic selection of CD31(+) cells from tonsil B cells increased by a factor of 12 the proportion of PC, determined as CD38(high) cells. This method recovered half of the initial number of PC, and did not alter the PC functions, because IgG secretion was similar in control B cell cultures as well as in cultures of B cells obtained at successive steps of the selection procedure. In addition, CD38(high) cells pre-enriched by this technique were readily isolated by FACS sorting and clearly identified as PC.
  
  
  CONCLUSIONS
  Therefore, immunomagnetic pre-enrichment of CD31(+) cells is an efficient method that allows the complete purification of human functional PC.
authors.affiliation: Servicio de Inmunología, Hospital Universitario Puerta del Mar, Cádiz, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Medina
authors.forename: C
authors.initials: C
authors.lastname: Segundo
authors.forename: J A
authors.initials: JA
authors.lastname: Brieva
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D002478:Cells, Cultured; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D014066:Palatine Tonsil / Q000166:cytology / Q000276:immunology*; D010950:Plasma Cells / Q000166:cytology* / Q000276:immunology; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D014068:Tonsillectomy
chemical_list: D015703:Antigens, CD; D019408:Platelet Endothelial Cell Adhesion Molecule-1