ABSTRACT
The interleukin-2 (IL2)-induced plastic-adherent spleen cells were shown to have the morphology of large granular lymphocytes and phenotypic and functional characteristics of NK cells. Culture of these NK cells selected by adherence to plastic in the presence of IL2 resulted in their rapid expansion. The initially adherent population of NK cells grew as a single-cell suspension and had high levels of antitumor cytotoxicity against a large variety of NK-cell sensitive and resistant tumor cell targets but not against normal cells. The chapter describes phenotypic and functional characteristics of a subset of human NK cells. The in vivo experiments in animal models and the phase one clinical trial in patients with advanced cancer described above focused attention on A-LAK cells and resulted in a more extensive evaluation of their functional characteristics. A significantly higher proportion of A-NK than NA-NK cells proliferated after 48 to 96 hour culture in the presence of IL2. This observation was confirmed by standard 3[H]thymidine incorporation assays as well as by cell counts performed at different times during culture.
