Induction of lymphokine-activated killer activity in rat splenocyte cultures: the importance of 2-mercaptoethanol and indomethacin.
The role of 2-mercaptoethanol and indomethacin in the induction of lymphokine-activated killer (LAK) activity by interleukin-2 (IL-2) in rat splenocyte cultures was investigated. Spleens from 4-month-old male rats of five different strains were tested. Splenocytes were cultured for 3-5 days in the presence of IL-2 (1000 U/ml) and LAK activity was assessed by 4-h 51Cr release assays with P815 and YAC-1 cells as targets. LAK activity could be induced by IL-2 in splenocytes from all rat strains, but only when 2-mercaptoethanol was present in the culture medium. Optimal LAK activity was induced when the 2-mercaptoethanol concentration in splenocyte cultures was at least 5 microM. Different rat strains showed differences in levels of in vitro induction of LAK activity. In the presence of 2-mercaptoethanol the level of LAK activity induced by IL-2 was high in BN and Lewis rats, intermediate in Wistar and Wag rats, and low in DZB rats. In the absence of 2-mercaptoethanol no or minimal LAK activity was induced. Furthermore we observed that addition of 50 microns indomethacin to the culture medium in the presence of 2-mercaptoethanol augmented the induction of LAK activity to some extent. In the absence of 2-mercaptoethanol, addition of indomethacin resulted only in low levels or no induction of LAK activity. We conclude that for optimal induction of LAK activity by IL-2 in rat splenocyte cultures 2-mercaptoethanol is essential, while indomethacin can only marginally further improve this induction.
Kuppen
P J
PJ
Department of Pathology, University of Leiden, The Netherlands.
Eggermont
A M
AM
Marinelli
A
A
de Heer
E
E
van de Velde
C J
CJ
Fleuren
G J
GJ
D000818:Animals; D002478:Cells, Cultured; D002860:Chromium Radioisotopes; D003601:Cytotoxicity Tests, Immunologic; D007213:Indomethacin / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology; D015979:Killer Cells, Lymphokine-Activated / Q000187:drug effects*; D008297:Male; D008623:Mercaptoethanol / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000166:cytology* / Q000187:drug effects
D002860:Chromium Radioisotopes; D007376:Interleukin-2; D008623:Mercaptoethanol; D007213:Indomethacin