Rapid lupus autoantigen relocalization and reactive oxygen species accumulation following ultraviolet irradiation of human keratinocytes.
OBJECTIVE
In vitro treatment with ultraviolet B (UVB) induces relocalization of lupus autoantigens to the cell surface. We have addressed the relationship between autoantigen relocalization, accumulation of intracellular reactive oxygen species (ROS) and the induction of apoptosis following UVA and UVB exposure.


METHODS
Human primary keratinocytes were exposed in vitro to doses of UVA and UVB equivalent to 0.01-4 times the minimal erythemal dose. The cellular locations of Ro60, Ro52, Sm, U2-B" and La were determined using monoclonal antibodies. ROS accumulation and apoptosis induction were assessed using the intracellular ROS probe 2'7'-dichlorodihydrofluorescein diacetate, and the viability stains Hoechst 33342 and propidium iodide.


RESULTS
UV treatment induced the relocalization of all five autoantigens investigated and an accumulation of ROS. UVA and UVB induced necrosis and apoptosis, respectively.


CONCLUSIONS
These data suggest that both UVA and UVB induce ROS within keratinocytes but have significantly different effects upon autoantigen relocalization and cell viability.
Lawley
W
W
Division of Chemical Pathology, Centre for Mechanisms of Human Toxicity, Hodgkin Building, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK.
Doherty
A
A
Denniss
S
S
Chauhan
D
D
Pruijn
G
G
van Venrooij
W J
WJ
Lunec
J
J
Herbert
K
K
D000954:Antigens, Surface / Q000378:metabolism; D017209:Apoptosis / Q000528:radiation effects; D001324:Autoantigens / Q000378:metabolism*; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008297:Male; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009336:Necrosis; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism; D014466:Ultraviolet Rays
D000954:Antigens, Surface; D001324:Autoantigens; D017382:Reactive Oxygen Species; D012261:Ribonucleoproteins