TY - JOUR
T1 - Generation of novel covalent RNA-protein complexes in cells by ultraviolet B irradiation
T2 - Implications for autoimmunity
AU - Andrade, Felipe
AU - Casciola-Rosen, Livia A.
AU - Rosen, Antony
PY - 2005/4
Y1 - 2005/4
N2 - Objective. To determine whether ultraviolet B (UVB) irradiation induces novel modifications in autoantigens targeted during experimental photoinduced epidermal damage. Methods. To search for novel UVB-induced autoantigen modifications, lysates made from UVB-irradiated human keratinocytes or HeLa cells were immunoblotted using human autoantibodies that recognize ribonucleoprotein autoantigens. Novel autoantigen structures identified were further characterized using nucleases and RNA hybridization. Results. Human sera that recognize U1-70 kd (U1-70K) and La by immunoblotting also recognized multiple novel species when they were used to immunoblot lysates of UVB-irradiated keratinocytes or HeLa cells. These species were not present in control cells and were not observed when apoptosis was induced by Fas ligation or cytotoxic lymphocyte granule contents. Biochemical analysis using multiple assays revealed that these novel UVB-induced molecular species result from the covalent crosslinking between the U1 RNA and the hYRNA molecules with their associated proteins, including U1-70K, La, and likely components of the Sm particle. Conclusion. These data demonstrate that UVB irradiation of live cells can directly induce covalent RNA-protein complexes, which are recognized by human autoantibodies. As previously described for other autoantigens, these covalent complexes of RNA and proteins may have important consequences in terms of antigen capture and processing.
AB - Objective. To determine whether ultraviolet B (UVB) irradiation induces novel modifications in autoantigens targeted during experimental photoinduced epidermal damage. Methods. To search for novel UVB-induced autoantigen modifications, lysates made from UVB-irradiated human keratinocytes or HeLa cells were immunoblotted using human autoantibodies that recognize ribonucleoprotein autoantigens. Novel autoantigen structures identified were further characterized using nucleases and RNA hybridization. Results. Human sera that recognize U1-70 kd (U1-70K) and La by immunoblotting also recognized multiple novel species when they were used to immunoblot lysates of UVB-irradiated keratinocytes or HeLa cells. These species were not present in control cells and were not observed when apoptosis was induced by Fas ligation or cytotoxic lymphocyte granule contents. Biochemical analysis using multiple assays revealed that these novel UVB-induced molecular species result from the covalent crosslinking between the U1 RNA and the hYRNA molecules with their associated proteins, including U1-70K, La, and likely components of the Sm particle. Conclusion. These data demonstrate that UVB irradiation of live cells can directly induce covalent RNA-protein complexes, which are recognized by human autoantibodies. As previously described for other autoantigens, these covalent complexes of RNA and proteins may have important consequences in terms of antigen capture and processing.
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U2 - 10.1002/art.20992
DO - 10.1002/art.20992
M3 - Article
C2 - 15818701
AN - SCOPUS:17244382409
SN - 0004-3591
VL - 52
SP - 1160
EP - 1170
JO - Arthritis and rheumatism
JF - Arthritis and rheumatism
IS - 4
ER -