Hyperthermia and host-cell reactivation of adenovirus 12

Exposure of cultured human fibroblasts to hyperthermia delayed the host-cell reactivation of UV-irradiated human adenovirus type 12 (AD12). The experimental design consisted of irradiating human AD12 with UV doses ranging from 180 to 1800 ergs/mm2, infecting human cell populations at 37 degrees C, exposing the infected cells for 7 h to 39.5 degrees C and 41.8 degrees C, returning them to 37 degrees C and estimating the frequency of cells with intranuclear viral inclusion bodies (IB) 41 and 89 h after hyperthermia treatment. Hyperthermia reduced the fractions of fibroblasts with viral IB in the 41 h samples. By 89 h the capacity to form IB in the treated cells was comparable to that in control cells. Hyperthermia of 39.5 and 41.8 degrees C for 7 h did not affect the replication of nonirradiated AD12. The pattern of host-cell reactivation of AD12 following hyperthermia was compared to that in DNA repair deficient xeroderma pigmentosum cell populations.