Effect of Separate and Combined Injections of Poly rI: Poly rC and Endotoxin on Reticulo-endothelial Activity, Interferon, and Antibody Production in the Mouse

The effect of repeated stimulation on both the interferon and antibody systems and on reticuloendothelial activity was studied by injection of endotoxin 2 days before injection of (poly rI):(poly rC). A single injection of endotoxin or (poly rI):(poly rC) increased or decreased the response in each system depending on the time of administration. If the injection of (poly rI):(poly rC) was preceded by an injection of endotoxin 2 days before, its activity was markedly reduced in all of the three systems studied. Although different doses of endotoxin were required to induce a state of hyporeactivity or tolerance to the effects of (poly rI):(poly rC) in either system, it is possible that a common mechanism underlies the hyporeactivity in all systems.