Consequences of herpes simplex virus type 2 and human cell interaction at supraoptimal temperatures

Abstract

The consequences of herpes simplex virus type 2 (HSV-2) and human embryonic fibroblast cell interaction at different temperatures (37, 40 and 42.degree. C) were investigated. Incubation at 37 or 40.degree. C was permissive for HSV-2 inhibition of host DNA synthesis, induction of virus-specific DNA replication and infectious virus production. The amount of [methyl-3H]thymidine incorporated into viral DNA and the final yield of new infectious virus were significantly reduced at 40.degree. C compared to 37.degree. C. At 42.degree. C, detectable virus-specific DNA synthesis was totally blocked. Maximum stimulation of host cell DNA synthesis at 42.degree. C was measured after a multiplicity of infection of 0.5-1.0 PFU[plaque-forming units]/cell. By autoradiography, data indicated that HSV-2 stimulates host cell chromosomal DNA synthesis. Stimulation of thymidine kinase activity with thermostability properties in common with a virus enzyme was detected during the 1st 24 h of infection at 42.degree. C; after 24 h the enhanced thymidine kinase activity had properties in common with host cell isozymes. Stimulation of host cell DNA synthesis apparently does not require viral DNA synthesis.