Antigenic properties of UV irradiated DNA as a function of spectral region and time

It is already known that UV irradiation in systemic lupus erythematosus (SLE), a disease of unknown etiology, denatures DNA in cells of the skin. We considered the change ofantigenic properties of UV irradiated DNA depending on UV spectral region and time of exposure to UV rays. Native DNA was irradiated and tested with antibodies from anti-DNA positive sera of lupus patients. We obtained negative DNA-antiDNA reactions ranging from 32,10 to 91,67% of the control for the spectral region peaking at 254 nm, and from 12,50 to 41,66% for the spectral region peaking at 365 nm. The data agree with the etiology of SLE but also indicate a specific type of denaturation caused by UV rays differing from thermal or sonar denaturation. The results also give support to further investigations in respect to the formation of antibodies characteristic for the time of UV irradiation.