Temperature optima of mammalian and amphibian viruses in cell cultures of homeothermic and poikilothermic origin.

Abstract

The effect of incubation temperature on the growth of the mammalian viruses HSV and vaccinia and the amphibian viruses FV-1 and LT-1 was studied in cell cultures of mammalian, avian and reptilian origin. Unlike the mammalian (monkey) and avian (chick) cells, cells of the reptilian cell line TH-1A multiplied at optimal rates at 23°C and 30°C but did not multiply at 36° C. Despite the different temperature optima of the host cells studied, the mammalian viruses replicated at maximum rates at 36° C and the amphibian viruses replicated at maximum rates at 23° C in each host cell type. At the intermediate temperature of 30° C near maximal rates of replication of both amphibian and mammalian viruses were usually observed. However, at this temperature the turtle cell line TH-1A supported reduced rates of replication of both the “warm optimum” vaccinia virus and the“cool optimum” LT-1 and FV-1 viruses. The results suggest that the viral genome is the major determinant of the temperature required for synthesis of a given virus, but the host cell may influence the finer limits of the temperature range supporting replication.