The Role of Double-Stranded RNA in Induction of the Acute-Phase Response in an Abortive Influenza Virus Infection Model

Abstract

The inducer of the acute-phase response in “flu-like” viral infections is not defined, The hypothesis that virus-associated double-stranded (ds) RNA serves this function was investigated by comparison of several acute-phase responses (fever and sleep patterns, white and nucleated red blood cell levels,serum antiviral activityand ceruloplasmin) induced by the synthetic dsRNA polyriboinosinic:polyribocytidylic acid (poly[rI:rC]) with those induced by influenza virus in rabbits. The capacity of either dsRNA or influenza virus to induce hyporesponsivenesswith respect to these acute-phase parameters upon rechallenge with the same agent or cross-challenge 24 h later was also examined, Poly(rI:rC) induced only minimal hyporesponsivenessto itself but wasa potent inducer of hyporesponsiveness to virus with respect to fever, sleep, leukograms, and antiviral activity. Therefore, poly(rI:rC) can substitute for virus in terms of induction of acutephase hyporesponsiveness, suggesting that dsRNA of viral origin triggers the acute-phase response in this model of influenza.