Study of temperature-dependent inhibition of reproduction of some picornaviruses by aurantine and mitomycin.

Abstract

Aurantine, a preparation consisting of a mixture of actinomycins C3 and C2, is capable under certain conditions to inhibit reproduction of poliomyelitis and encephalomyocarditis viruses. The effectiveness of inhibition depends upon the type of cell culture, virus strain and particularly upon temperature. Increase of incubation temperature markedly enhanced the antiviral effect of aurantine. The latter exerts its inhibiting effect in the second half of the eclipse period and prevents accumulation of the viral RNA. If the sensitive period takes place in the absence of the antibiotic or in its presence but at sufficiently low temperature, the subsequent stages of the synthesis of virus components and virion maturation may take place in the presence of aurantine even at relatively high temperature. Inhibition of protein synthesis by puromycin prevents occurrence in the absence of aurantine of processes sensitive to the latter antibiotic. Guanidine prevents these processes only partially and if the infected cells are incubated in hypotonic medium, these processes appear to occur completely. At a sufficiently high temperature of incubation reproduction of poliomyelitis and encephalomyocarditis viruses is inhibited also in the presence of mitomycin C. Various possible explanations of the data obtained are discussed in particular, a hypothesis according to which the virus infection induces formation of a certain cellular protein which is necessary for normal virus reproduction to a greater extent at supraoptimal than at relatively low temperatures.