[Neutralizing antibodies to human gamma-interferon]

Spleen lymphocytes from normal subjects who suddenly died were used as cells producing gamma-interferon. One spleen yielded (3-8) X 10(8) viable cells which made it possible to prepare from 3 to 81 of splenocyte suspension culture. Staphylococcal enterotoxin A (SEA) and B (SEB) were used as gamma-interferon inducers. Stimulation of splenocyte suspension culture with SEA and SEB resulted in production of gamma-interferon with an average activity of 640-2560 units/ml. A partially purified interferon preparation with an activity of 2 X 10(4) units/ml was obtained by sorption of gamma-interferon on porous glass CPG-200-240 followed by elution with a buffer containing 50% ethylene glycol and Sephadex G-25 gel chromatography. As a result of 11 successive intramuscular immunizations of rabbits at 2-week intervals with a partially purified and concentrated preparation of gamma-interferon with Freund's complete adjuvant, blood serum was obtained which was capable of neutralizing 32 units of gamma-interferon up to a dilution of 1:128. The serum was highly specific: it showed no specific interaction with antigenic determinants of either natural alpha- and beta- or plasmid alpha-F and alpha-F/D human interferons.