Action of recombinant interferons and interleukin 2 in modulating radiation effects on viability and cytotoxicity of large granular lymphocytes.
We have evaluated in vitro the modulating effect of interferon (IFN) alpha, beta and gamma as well as interleukin 2 (IL-2) on the radiosensitivity of large granular lymphocytes (LGL) having natural killer cell activity. LGL were treated with IFNs or IL-2 in concentrations from 1 to 1000 U/ml before or after a single or a split dose of irradiation. The viability of LGL was measured by intracellular ATP, and cytotoxicity by a 51Cr release assay. Both viability and cytotoxicity were clearly higher when IFNs and IL-2 were used before irradiation. Some IFNs were slightly radiosensitizing in ATP studies. Only IFN gamma in a concentration of 1000 U/ml was significantly radioprotective in cytotoxicity tests when used before irradiation. IL-2 had a significant concentration-dependent radioprotective effect in cytotoxicity when used before or after irradiation, and in the viability of preincubated LGL. No combination of IFNs and IL-2 was more radioprotective than IL-2 used alone. IL-2 retarded the time dependent decrease of ATP and 51Cr release levels after irradiation. According to our results, IL-2 is a radioprotective substance for LGL.
Hietanen
T
T
Department of Oncology, Tampere University Hospital, Finland.
Kellokumpu-Lehtinen
P
P
Pitkänen
M
M
D000255:Adenosine Triphosphate / Q000032:analysis; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000528:radiation effects*; D006801:Humans; D007372:Interferons / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000528:radiation effects*; D011994:Recombinant Proteins / Q000494:pharmacology
D007376:Interleukin-2; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D007372:Interferons