Bovine interleukin 2: production and characterization

The production of bovine IL 2 was studied and IL 2 was partially characterized. PMA at 5 ng/ml + Concanavalin A at 5 micrograms/ml treatment of peripheral blood mononuclear cells gave a greater yield of IL 2 activity in the supernatants than Con A, PMA or sodium periodate treatments alone. Macrophage depletion increased yields as did the addition of indomethacin, a prostaglandin E2 inhibitor. Bovine IL 2 was sensitive to trypsin, relatively stable at pH 2-9, 2-ME resistant and sensitive to increasing molar concentrations of urea. The activity of bovine IL 2 was reduced by over 45% at 70 degrees C for 30 min and 95% at 90 degrees C for 30 min. Bovine IL 2 was more stable at 4 degrees C than at room temperature and the stability at room temperature could be improved by inclusion of 1% BSA. Bovine IL 2 eluted from DEAE-Sephadex as a broad peak with 0.1-0.2 M NaCl. Peak activity corresponded to a molecular weight of approximately 16,000 daltons on Sephadex G-100.