title: [Human peripheral blood CD56+ natural killer cell subsets and their phenotypic and biological properties].
abstract: OBJECTIVE
  To characterize the phenotypic and biological properties of CD56(+) natural killer cells from human peripheral blood mononuclear cells (PBMCs).
  
  
  METHODS
  Surface markers and intracellular cytotoxic molecules were stained with multi-color-labeled monoclonal antibodies and analyzed at the single cell level the relation between NK subsets and biological characteristics by flow cytometry.
  
  
  RESULTS
  NK cells in PBMCs could be divided into two major populations, CD56(bright) and CD56(dim), based upon the expression of CD56 molecules. Both CD56(bright) and CD56(dim) expressed CD95 (Fas) with CD95(bright) and CD95(dim) subsets. CD56(dim) subsets had higher percentage of CD8, granzyme B and perforin expression compared to those of CD56(bright) subsets. In CD56(bright) and CD56(dim) subpopulations, CD95(bright) and CD8(+) subsets had higher percentage of granzyme B and perforin expression.
  
  
  CONCLUSIONS
  CD56(+) NK cells in PBMCs are composed of distinct subpopulations, CD56(dim) and CD56(dim) CD8(+) NK subsets have higher percentage of granzyme B and perforin and may play an important role in the killing of target cells.
authors.affiliation: Department of Immunology, Medical School, Sun Yat-sen University, Guangzhou 510080, China. changyou_wu@yahoo.com
authors.forename: Chang-you
authors.initials: CY
authors.lastname: Wu
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Bin-yan
authors.initials: BY
authors.lastname: Yang
authors.forename: Mario
authors.initials: M
authors.lastname: Roedere
mesh_terms: D019002:CD56 Antigen / Q000378:metabolism*; D016827:CD8 Antigens / Q000378:metabolism; D053804:Granzymes / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000145:classification / Q000276:immunology* / Q000378:metabolism; D016131:Lymphocyte Subsets / Q000276:immunology; D054353:Perforin / Q000378:metabolism; D010641:Phenotype; D019014:fas Receptor / Q000378:metabolism
chemical_list: D019002:CD56 Antigen; D016827:CD8 Antigens; D019014:fas Receptor; D054353:Perforin; D053804:Granzymes