- Volume 42, Issue 3, 1979

A persistent infection with rabies virus (HEP-Flury) was established in the CNS-derived hybrid cell line 108 CC15 which possesses specific membrane receptors for prostaglandins, catecholamines and acetylcholine. We report a differential virus influence on the specific receptor response to PGE, isoproterenol and acetycholine as indicated by typical changes of the intracellular cyclic AMP levels.

As the adenylate cyclase activity was unchanged in infected cells in vitro, a selective virus influence on specific receptors themselves or their coupling to the cAMP synthesizing system must be considered.

The circular DNA molecules of cotton bollworm nuclear polyhedrosis virus, visualized by electron microscopy, have a mol. wt. of 81 × 106. In addition, renaturation kinetics studies suggest a genetic complexity corresponding to a mol. wt. of 82 × 106. A G + C content of 42% for the virus DNA is estimated from its thermal denaturation profile and buoyant density in CsCl.

Establishment and characteristics of a baby hamster kidney cell line (BHK 0-853) persistently infected with a subacute sclerosing panencephalitis (SSPE) strain of measles virus (Lec strain) is described. The persistent infection was easily and repeatedly established and no special conditions were required. There was a predictable fluctuation in expression of virus intracellular and membrane antigens which varied from greater than 90% to less than 1% of the cells demonstrating these antigens during the first 6 or 7 passages. Thereafter, fluctuation of antigen and infectious virus expression continued in an unpredictable fashion.

Culex annulirostris mosquitoes infected with SFV-S, a temperature-sensitive, small-plaque mutant of Semliki Forest virus isolated from cultured Aedes albopictus cells, could not be infected later with wild-type virus (SFV-W). Interference occurred as soon as 24 h after infection with SFV-S. In mosquitoes infected with a mixture of the two viruses, both replicated normally.

Immunoprecipitates obtained by reacting Dane particle cores with human antibodies to hepatitis B core antigen (HBcAg) were chromatographed on columns of Sepharose 4B CL using 3 m-NaSCN as eluant. An antigen having the size and immunological specificity of monomeric e-antigen (HBeAg) was separated from HBcAg by this method. Antisera from animals immunized with HBcAg or HBeAg reacted not only with the antigen used for immunization but also with HBeAg and HBcAg, respectively. This indicates that HBeAg determinants are associated with the core of Dane particles.

The highly oncogenic human adenovirus type 12 temperature sensitive mutant, H12ts401, is unable to maintain the growth characteristics of transformed cells at the non-permissive temperature. In lytic infection, the 401 gene function is required to produce virus DNA. In the present study, virus DNA synthesized in ts401-infected human cells after temperature shift-up was characterized. No apparent suppression of DNA chain elongation or ligation occurs at the non-permissive temperature, but, as shown by density labelling, new initiation of virus DNA replication is inhibited under this condition. The results indicate that the 401 gene function is involved in the initiation of virus DNA synthesis in the lytic cycle.