In vitro propagation of cultured human natural killer cells expressing the HNK-1 differentiation antigen and spontaneous cytotoxic function.
Human natural killer (NK) cells expressing the HNK-1 differentiation antigen were established in long-term tissue culture for over 3 months. The fluorescence-activated cell sorter-purified HNK-1+ cells required both phytohemagglutinin and exogenous interleukin 2 to propagate in long-term culture. After 2 weeks of culture, virtually all of the growing cells exhibited the surface membrane phenotype associated with immature HNK-1+ cells, since they simultaneously expressed the HNK-1, Leu-4 and Leu-2a but lacked the M1. Leu-3a and T6 antigens, and Fc gamma receptors. They exhibited a lymphoblastoid appearance, contained cytoplasmic granules, and exhibited spontaneous cytotoxic function against a broader spectrum of target cells than did fresh HNK-1+ cells from the same donor. Cultured HNK-1+ cells lacked antibody-dependent cell-mediated cytotoxic (ADCC) function, while fresh HNK-1+ were fully capable of ADCC function. On the other hand, cultured HNK-1- cells were lymphoblasts without cytoplasmic granules or NK cytotoxic function. The cultured HNK-1+ cells gradually lost their HNK-1 antigen expression over time, although the expression of other surface antigens (e.g., Leu-4 and Leu-2a) was unchanged. With prolonged culture (greater than 2 months), they also exhibited decreasing cytotoxic function and a diminished number of cytoplasmic granules. They were eventually indistinguishable from HNK-1- cells after 3 months of culture. These observations were not influenced by adding interferon-gamma to the cultures. The results demonstrate that the immature form of NK cells (that express T cell antigens) preferentially proliferate in long-term cultures when incubated with phytohemagglutinin and interleukin 2.
D000328:Adult; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005455:Fluorescent Antibody Technique; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D007700:Kinetics; D008875:Middle Aged; D010641:Phenotype; D011961:Receptors, Fc / Q000032:analysis
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D011961:Receptors, Fc