THE GROWTH KINETICS OF AN ATTENUATED POLIOVIRUS TYPE 1 STRAIN, LSc, 2ab AT AN ELEVATED TEMPERATURE

An appreciable increase in viral RNA polymerase, infectious RNA and infectious virus particles was noticed when HeLa cell cultures infected with an attenuated poliovirus type 1 strain, LSc, 2ab, were maintained at 40 C. The induction of a very small, but significant amount of viral RNA polymerase was always observed in infected cells kept at 40 C. Increase in RNase-resistant infectious RNA was the most remarkable, amounting to from 10 to 30% of that produced at 35 C. The ratio of the amount produced at 40 C to that produced at 35 C was 1 to 3% with total infectious RNA and about 0.01% with infectious virus particles, which could be unmasked only by the use of photosensitive virus as inoculum.<BR>The heat sensitivity in situ or in vitro of the LSc, 2ab-induced RNA polymerase and the Mahoney-induced one was compared and both enzymes showed approximately the same rate of inactivation.<BR>ARLINGHAUS, R. B. AND POLATNICK, J. (1969) : The isolation of two enzyme-ribonucleic acid complexes involved in the synthesis of foot-and-mouth diseases virus ribonucleic acid. Proc. Natl. Acad. Sci. U. S., 62, 821-828.<BR>BALTIMORE, B. AND FRANKLIN, R. M. (1963) : A new ribonucleic acid polymerase appearing after mengovirus infection of L-cells. J. Biol. Chem., 238, 3395-3400.<BR>BALTIMORE, D., BECKER, Y. AND DARNELL, J. E. (1964) : Virus-specific double-stranded RNA in poliovirus-infected cells. Science, 143, 1034-1036.<BR>BISHOP, J. M., SUMMERS, D. F. AND LEVINTOW, L. (1965) : Characterization of ribonucle-ase-resistant RNA from poliovirus-infected HeLa cells. Proc. Natl. Acad. Sci. U. S., 54, 1273-1281.<BR>BISHOP, J. M. AND KOCH, G. (1967) : Purification and characterization of poliovirus-induced infectious double-stranded ribonucleic acid. J. Biol. Chem., 242, 1736-1743.<BR>COOPER, P. D. (1966) : The inhibition of poliovirus growth by actinomycin D and the prevention of the inhibition by pretreatment of the cells with serum or insulin. Virology, 28, 663-678.<BR>GRADO, C., FISCHER, S. AND CONTRERAS, G. (1965) : The inhibition by actinomycin D of poliovirus multiplication in HEp 2 cells. Virology, 27, 623-625.<BR>HSIUNG, G. D. AND MELNICK, J. L. (1955) : Plaque formation with poliomyelitis, coxsackie, and orphan (echo) viruses in bottle cultures of monkey epithelial cells. Virology, 1, 533-535.<BR>LODISH, H. F. AND ZINDER, N. D. (1966) : Replication of the RNA of bacteriophage f2. Science, 152, 372-378.<BR>LWOFF, A. (1969) : Death and transfiguration of a problem. Bacteriol. Rev., 33, 390-403.<BR>MÉNARD, D. AND LWOFF, A. (1967) : Existence probable de deux RNA replicases chez le poliovirus. Compt. Rend. Acad. Sci. Paris, 246, Série D, 2350-2352.<BR>NICOL, F. R. AND TERSHAK, D. R. (1968) : Rescue of temperature-sensitive poliovirus. J. Virol., 2, 415-420.<BR>PAGANO, J. S. AND VAHERI, A. (1965) : Enhancement of infectivity of poliovirus RNA with diethylaminoethyl-dextran (DEAE-D) . Arch, ges. Virusforsch., 17, 456-464.<BR>PRIEss, H. AND EGGERS, H. J. (1968) : Synthesis and activity of RNA polymerase of a temperature sensitive poliovirus mutant at an elevated temperature. Nature, 220, 1047-1048.<BR>SABIN, A. B. AND LWOFF, A. (1959) : Relation between reproductive capacity of polioviruses at different temperatures in tissue culture and neurovirulence. Science, 129, 1287-1288.<BR>SCHAFFER, F. L. AND GORDON, M. (1966) : Differential inhibitory effects of actinomycin D among strains of poliovirus. J. Bacteriol., 91, 2309-2316.<BR>TERSHAK, D. R. (1969) : Synthesis of ribonucleic acid in cells infected with LSc poliovirus at elevated temperatures. J. Virol., 3, 297-303.<BR>WILSON, J. N. AND COOPER, P. D. (1965) : The effect of light on poliovirus grown in neutral red. Virology, 26, 1-9.