TY - JOUR
T1 - Autoantigenicity of DFS70 is restricted to the conformational epitope of C-terminal alpha-helical domain
AU - Ogawa, Yasushi
AU - Sugiura, Kazumitsu
AU - Watanabe, Akihiro
AU - Kunimatsu, Mitoshi
AU - Mishima, Masaki
AU - Tomita, Yasushi
AU - Muro, Yoshinao
PY - 2004/11
Y1 - 2004/11
N2 - Autoantibodies against DFS70 (Dense Fine Speckles 70) are found in 30% of Japanese atopic dermatitis patients, and less frequently in patients with other diseases. We have recently reported that they are also seen in 11% of hospital workers, but in only ∼2% of patients with systemic rheumatic disease. In this study, in order to investigate the possible pathological role of anti-DFS70 antibodies, fine epitope mapping was carried out using 93 anti-DFS70 autoantibody-positive sera. Immunoblotting using overlapping peptides failed to reveal major linear epitopes. Western blotting using various truncated proteins showed a strikingly uniform epitope distribution on a suspected tertiary structure expressed by DFS70349-435. Some sera showed reactivity only in an immunoprecipitation assay using an in vitro translated DFS70. Circular dichroism analysis revealed that DFS349-435 contains an approximately 40% alpha-helical conformation, while an overlapping, non-antigenic peptide is composed of random coiled structures. The skewed single major epitope enabled us to establish a highly quantitative ELISA for the epitope region. Antibody titers showed no significant differences between the diseased group and healthy individuals. We propose that anti-DFS70 antibody may be a natural autoantibody, which might modify or reflect the inflammatory process of various disorders.
AB - Autoantibodies against DFS70 (Dense Fine Speckles 70) are found in 30% of Japanese atopic dermatitis patients, and less frequently in patients with other diseases. We have recently reported that they are also seen in 11% of hospital workers, but in only ∼2% of patients with systemic rheumatic disease. In this study, in order to investigate the possible pathological role of anti-DFS70 antibodies, fine epitope mapping was carried out using 93 anti-DFS70 autoantibody-positive sera. Immunoblotting using overlapping peptides failed to reveal major linear epitopes. Western blotting using various truncated proteins showed a strikingly uniform epitope distribution on a suspected tertiary structure expressed by DFS70349-435. Some sera showed reactivity only in an immunoprecipitation assay using an in vitro translated DFS70. Circular dichroism analysis revealed that DFS349-435 contains an approximately 40% alpha-helical conformation, while an overlapping, non-antigenic peptide is composed of random coiled structures. The skewed single major epitope enabled us to establish a highly quantitative ELISA for the epitope region. Antibody titers showed no significant differences between the diseased group and healthy individuals. We propose that anti-DFS70 antibody may be a natural autoantibody, which might modify or reflect the inflammatory process of various disorders.
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U2 - 10.1016/j.jaut.2004.07.003
DO - 10.1016/j.jaut.2004.07.003
M3 - Article
C2 - 15501393
AN - SCOPUS:14244257153
VL - 23
SP - 221
EP - 231
JO - Journal of Autoimmunity
JF - Journal of Autoimmunity
SN - 0896-8411
IS - 3
ER -