Transformation of mammalian cells by DNA-containing viruses following photodynamic inactivation

Mechanisms of photodynamic inactivation of herpes simplex viruses: comparison between methylene blue, light plus electricity, and hematoporhyrin plus light.

“…Photoactive dyes such as proflavine or neutral redl have been shown to inhibit the plaque-forming ability of HSV after photoirradiation of either infected cells or a suspension of dye and virus (4-7) by a process known as photodynamic inactivation (PDI). This technique not only inactivates HSV, but the resulting particles can transform hamster embryo fibroblasts (6). The molecular biologic targets critical for PDI by heterotricyclic compounds have not been elucidated, but Khan et al (5) have suggested that irradiation of infected cells pretreated with proflavine interferes with viral productioni at a step subsequient to DNA svnthesis.…”

Photoinactivation of Latent Herpes Simplex Virus in Rabbit Kidney Cells

“…Extracellular HSV particles have been shown to be photosensitive either when extracellular virus is exposed to neutral red or proflavine (1,17) or when the virus is grown in cells in medium containing the dye (11). It was the aim of this study to look at the photosensitizing ability of these agents on virus within viable cells.…”

“…The overall effectiveness of photosensitization therapy has yet to be proven, and potential hazards of the treatment have been brought up (11). In experimental studies virus has been inactivated by exposure to light both after extracellular virus was treated with dye (1, 17) and after virus was grown in cells treated with dye and then separated from the cellular material (11). In the present study we have treated cultures with neutral red and proflavine in an attempt to inactivate virus within the infected cells.…”

“…These studies include cases of herpetic eye infections (7,9,16) and genital herpes lesions (4,5) as well as primary and recurrent oral and skin lesions. The overall effectiveness of photosensitization therapy has yet to be proven, and potential hazards of the treatment have been brought up (11). In experimental studies virus has been inactivated by exposure to light both after extracellular virus was treated with dye (1, 17) and after virus was grown in cells treated with dye and then separated from the cellular material (11).…”

“…Herpes simplex virus (HSV) is inactivated by photosensitizing dyes such as neutral red and proflavine after exposure to visible light (1, 11,17). Experiments with other viruses have indicated that these dyes bind to the viral nucleic acid, resulting in the breakdown of guanine residues (3,(12)(13)(14)18).…”