Journal of Leukocyte Biology 45:21-28 (1989) © 1989 Alan R. Liss, Inc. Isolation and Characterization of Interleukin-1 From

lnterleukin-1 (IL-lot and lL-1 collectively) has been shown to be produced by a wide variety of cell types. The purpose of this study was to evaluate the ability of bovine polymorphonuciear leukocytos (PMN5) to synthesize and release IL-i-like cytokines and characterize the active molecule(s). Purified peripheral blood PMN8 were cultured for various periods of time in the presence of opsonized zymosan particles. The resulting culture supernatants exhibited IL-i activity as determined by enhanced mitogen-Induced proliferation of the D10 G4.1 murine T-helper cell line. Supernatants from nonstlmulated PMNs or PMNs stimulated for less than 6 h did not enhance D1O G4.1 proliferation. The active molecule (PMNIL-1) was isolated by using gel filtration high-performance liquid chromatography (HPLC). Further characterization of the HPLC-purified molecule by SOS-PAGE and Isoelectric focusing indicates bovine PMNIL-1 has a molecular weight of 17.8 kd and api of 4.1. Key words: cattle, neutrophils, IL-i, synthesi