Comparison of interferon production in mice by bacterial endotoxin and statolon

A comparison has been made of interferon production in mice injected intravenously with Escherichia coli endotoxin or statolon. Similar to previous findings with endotoxin, doses of cycloheximide which effectively blocked protein synthesis did not prevent the appearance of circulating interferon in mice injected with statolon. This finding indicates the existence of this interferon in a preformed state in the intact animal.Mice given two intravenous doses of either endotoxin or statolon, 48 hours apart, showed markedly diminished interferon response to the second injection of only the homologous stimulus. Pretreatment of mice with endotoxin failed to diminish significantly the response to statolon, and prior injection of statolon had no effect on the interferon titer produced with endotoxin. In addition, although endotoxin produced markedly enhanced levels of interferon in mice infected with attenuated tubercle bacilli (BCG), interferon production following different doses of statolon was not significantly different in infected and uninfected mice.These results are interpreted to mean that, although the interferons produced in mice by statolon and endotoxin are both present in a preformed state in the animal and both have similar molecular weights of 90,000, they are released from different cell populations or by different mechanisms.