The effect of cyclic nucleotides on virus infection.

The yield of influenza virus from infected primary chick kidney cells (PCKC) was enhanced by treatment with dcAMP. In addition, rapid serial passages of the virus in treated chick cells at low multiplicities did also exhibit maintenance of high virus titers. The action of dcAMP upon viral replication could be reproduced in the chick cells by treatment with various agents known to increase intracellular cAMP levels by differing mechanisms. Furthermore, an adrenergic component in the activation of the PCKC cAMP system is indicated by the effects of certain catecholamines on influenza virus yield. Dibutyryl cAMP was shown in the same host to inhibit multiplication of Herpesvirus hominis Type 2, and its effect on other cell-virus systems indicates that its action consists of some host-specific element(s).