A differentiation antigen of human NK and K cells identified by a monoclonal antibody (HNK-1)

J Immunol. 1981 Sep;127(3):1024-9.


A monoclonal IgM antibody (HNK-1) was produced against a membrane antigen from the cultured T cell line, HSB-2. By indirect immunofluorescence, this antibody reacted with certain human cultured T cell lines (HSB-2 and MOLT-4 but not MOLT-3) but not with other lines of B cell or phagocytic cell origin. HNK-1 reacted with 15.1 +/- 7.1% of normal blood lymphocytes but was unreactive with monocytes, granulocytes, erythrocytes, and platelets. HNK-1+ cells separated by a fluorescence-activated cell sorter (FACS) were a homogeneous population of medium sized lymphocytes with abundant neutrophilic cytoplasm containing azurophilic granules. HNK-1+ cells were nonadherent, surface Ig-, mostly FcIgG receptor+ and both positive and negative for demonstrable sheep erythrocyte (E) rosetting capability. Cell suspensions enriched for E-rosetting T cells and depleted of FcIgG receptor+ cells contained few (6%) HNK-1+ cells. Depletion of HNK-1+ cells from blood mononuclear cell populations by complement (C) mediated lysis greatly reduced NK activity against K-562 target cells and K cell lytic activity against antibody-coated chicken red blood cells. Treatment with HNK-1 alone or C alone did not affect these activities. When the FACS was utilized to separate HNK-1+ and HNK-1- cells from 6 individuals, the HNK-1+ cell population contained almost all of the NK and K cell function. The monoclonal antibody HNK-1 thus defines the first differentiation antigen shown to be selectively expressed on human NK and K cells.

Publication types

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

MeSH terms

  • Animals
  • Antibodies*
  • Antibodies, Monoclonal
  • Antigens, Surface*
  • Cells, Cultured
  • Humans
  • Killer Cells, Natural / immunology*
  • Lymphocytes / classification
  • Rabbits
  • T-Lymphocytes / cytology


  • Antibodies
  • Antibodies, Monoclonal
  • Antigens, Surface