Reassessment of the differential effects of ultraviolet and ionizing radiation on HIV promoter: the use of cell survival as the basis for comparisons.
Effects of different radiation treatments on the human immunodeficiency virus-1 (HIV) promoter were reassessed for exposures comparable to those encountered in clinical or cosmetic practice, using survival of the host cell as a basis for comparisons. The exposures were performed with two ultraviolet radiation sources commonly used as medical or cosmetic devices (UVASUN 2000 and FS20 lamps), a germicidal (G15T8) lamp and an X-ray machine. The UVC component of the FS20 lamp was filtered out. The emission spectra of the lamps were determined. The characteristics of these sources allowed us to discriminate among effects of UVA1 (340-400 nm), UVB + UVA2 (280-340 nm) and UVC (254 nm) radiations. Effects of irradiation were ascertained using cultures of HeLa cells stably transfected with the HIV promoter linked to a reporter-chloramphenicol acetyl transferase-gene. The exposures used caused at least two logs of cell killing. In this cytotoxicity range, UVA1 or X radiations had no effect on the HIV promoter, whereas UVB + UVA2 or UVC radiations activated the HIV promoter in a fluence-dependent manner. Survivals following exposure to UVB + UVA2 or UVC radiation were (1) at the lowest measurable HIV promoter activation, 30 and 20%, respectively, (2) at one-half maximal activation, 6 and 3%, respectively and (3) at the maximal activation, 0.5 and 0.2%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Beer
J Z
JZ
Center for Devices and Radiological Health, Food and Drug Administration, Rockville, MD 20857.
Olvey
K M
KM
Lee
W
W
Zmudzka
B Z
BZ
D002470:Cell Survival / Q000528:radiation effects; D015967:Gene Expression Regulation, Viral / Q000528:radiation effects; D015497:HIV-1 / Q000235:genetics / Q000528:radiation effects*; D006367:HeLa Cells; D006801:Humans; D011401:Promoter Regions, Genetic / Q000528:radiation effects*; D014466:Ultraviolet Rays