Interleukin 2 is not sufficient for the continuous growth of cloned NK-like cytotoxic cell lines.
Interleukin 2 (IL 2) has been strongly implicated as the agent responsible for the continuous growth of T cell lines in vitro. In the present study we confirmed that IL 2 alone could support the growth of a widely used cytotoxic T cell line. In contrast, we found that IL 2 was not sufficient to support the long-term growth of cloned NK-like cytotoxic lymphocyte cell lines. Whereas such lines would grow indefinitely in concanavalin A-induced mouse spleen cell supernatant, they would only grow for short periods (2 to 3 days) in the IL 2-containing supernatant of phytohemagglutinin-stimulated LBRM-33 tumor cells, or in IL 2 partially purified from spleen cell or LBRM-33 supernatants. The addition of concanavalin-A or interferon (type beta or gamma) to these supernatants did not improve growth. By contrast, the NK-like cells proliferated equally well in a short-term (24-hr) assay, irrespective of the source of IL 2 (spleen or LBRM-33 supernatant, or partially purified IL 2). Furthermore, the NK-like cells readily depleted IL 2 from the medium, either during growth at 37 degrees C or by absorption at 4 degrees C. It is concluded that at least some cytotoxic cell lines require both IL 2 and other, as yet unidentified, spleen cell-derived factors for long-term growth.
D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002470:Cell Survival; D002999:Clone Cells / Q000166:cytology; D003208:Concanavalin A / Q000494:pharmacology / Q000502:physiology; D003470:Culture Media; D007376:Interleukin-2 / Q000502:physiology*; D007694:Killer Cells, Natural / Q000166:cytology*; D008222:Lymphokines; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D051381:Rats; D011920:Rats, Inbred WF; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology*; D013997:Time Factors
D003470:Culture Media; D007376:Interleukin-2; D008222:Lymphokines; C021649:concanavalin A-induced helper factors; D003208:Concanavalin A