Raising antibodies to human leukocyte interferon

Human leukocyte interferon proved to be a good immunogen in sheep, rabbits and guinea pigs. Sera from immunized animals neutralized the antiviral action of leukocyte interferon at high dilution. The highest anti-interferon titres obtained were 1:1,200,000 for sheep, 1:150,000 for rabbits, 1:30,000 for guinea pigs. Partial purification of human leukocyte interferon, by ethanol precipitation, improved its qualities as an immunogen. While it appeared more efficient to give initial injections without adjuvant, the inclusion in booster injections, of Freund's complete adjuvant produced a markedly superior response and, in one sheep, maintained high levels of circulating antibody for several months.