title: CD39/NTPDase-1 activity and expression in normal leukocytes.
abstract: BACKGROUND
  CD39/NTPDase-1 is a cell surface enzyme expressed on leukocytes and endothelial cells that metabolizes ATP to ADP and AMP. CD39 is expressed on numerous different types of normal leukocytes, but details of its expression have not been determined previously.
  
  
  METHODS
  We examined CD39 expression and activity in leukocytes isolated from healthy volunteers. Expression of CD39 on leukocytes was measured by FACS and activity of CD39 in lymphocytes and neutrophils was determined by an enzymatic radio-TLC assay.
  
  
  RESULTS
  We established that CD39 is expressed on neutrophils, lymphocytes, and monocytes. The enzyme is found on >90% of monocytes, neutrophils, and B-lymphocytes, and 6% of T-lymphocytes and natural killer cells. Per cell density of expression varied, with the highest expression on monocytes and B-lymphocytes. ATPase and ADPase activities were highest on B-lymphocytes, lower on neutrophils, lowest on T-lymphocytes. The ratio of ADPase:ATPase activity was 1.8 for neutrophils and B-lymphocytes and 1.4 for T-lymphocytes. Hypertensive volunteers had lower levels of CD39 on their T-lymphocytes and NK cells. No correlation between age, gender, ethnic background, or cholesterol level and CD39 expression was observed.
  
  
  CONCLUSIONS
  We conclude that CD39 activity and expression are present to varying degrees on all leukocytes types examined. Differences between leukocyte types should be considered when examining CD39 in disease states.
authors.affiliation: Research Service, Veterans Affairs New York Harbor Healthcare System, New York, NY 10010, United States.
authors.forename: E Dianne
authors.initials: ED
authors.lastname: Pulte
authors.forename: M Johan
authors.initials: MJ
authors.lastname: Broekman
authors.forename: Kim E
authors.initials: KE
authors.lastname: Olson
authors.forename: Joan H F
authors.initials: JH
authors.lastname: Drosopoulos
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Kizer
authors.forename: Naziba
authors.initials: N
authors.lastname: Islam
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Marcus
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood*; D001081:Apyrase / Q000097:blood*; D001402:B-Lymphocytes / Q000201:enzymology / Q000276:immunology; D001774:Blood Chemical Analysis; D002469:Cell Separation; D002855:Chromatography, Thin Layer; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007962:Leukocytes / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D008934:Mitogens / Q000494:pharmacology; D009000:Monocytes / Q000201:enzymology / Q000276:immunology; D009504:Neutrophils / Q000201:enzymology / Q000276:immunology; D013601:T-Lymphocytes / Q000201:enzymology / Q000276:immunology
chemical_list: D015703:Antigens, CD; D008934:Mitogens; D001081:Apyrase; C067869:CD39 antigen