Cutting edge: the mouse NK cell-associated antigen recognized by DX5 monoclonal antibody is CD49b (alpha 2 integrin, very late antigen-2)

J Immunol. 2001 Aug 1;167(3):1141-4. doi: 10.4049/jimmunol.167.3.1141.


DX5 mAb is a useful reagent because it stains NK cells from all mouse strains examined. We have identified the molecule recognized by DX5 mAb by using a retrovirus-mediated expression cloning system. A 5-kb cDNA encoding a protein that is reactive with the DX5 mAb was isolated from a NK cell cDNA library, and this molecule was identical with CD49b (very late Ag-2, alpha(2) integrin). The DX5 mAb reacted with transfectants expressing CD49b, and binding of DX5 to the NK cells and CD49b transfectants was blocked in the presence of other anti-CD49b mAbs. When NK1.1(+) NK cells were cultured with IL-2, they progressively lost reactivity with DX5 mAb as a consequence of cellular proliferation. Cytotoxicity mediated by the DX5(+) NK cells was dramatically higher as compared with DX5(-) NK cells. Therefore, DX5 mAb recognizes CD49b and can be used to define functionally distinct subsets of NK cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / metabolism*
  • Antigen-Antibody Reactions
  • Antigens, CD / biosynthesis
  • Antigens, CD / genetics
  • Antigens, CD / immunology*
  • Antigens, CD / physiology
  • Cell Line
  • Cells, Cultured
  • Clone Cells
  • Cloning, Molecular / methods
  • Cytotoxicity Tests, Immunologic
  • Humans
  • Hybridomas
  • Integrin alpha2
  • Interleukin-2 / pharmacology
  • Jurkat Cells
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Rats
  • Rats, Inbred Lew


  • Antibodies, Monoclonal
  • Antigens, CD
  • Integrin alpha2
  • Interleukin-2