DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.48120#0135
Abstracts
117
Molecular Cloning of Ki Antigen C DNA and Enzyme-Linked-
Immunosorbent-Assay for Anti-Ki Using Recombinant Ki
Y. Takasaki1, M. Shibata2, K. Shimada3, T. Nikaidou3, Y. Nishida3,
M. Sakamoto1, H. Hashimoto1, and S. Hirose 1
'Juntendo University, Tokyo 113,
2 Med. Bio. Lab.
3Aichi Cancer Center, Nagoya, Japan
In 1981, TOJO et al. firstly reported anti-Ki antibody and showed its clinical
significance in lupus patients. But the characteristics of Ki antigen have not been
well defined. In this report, we attempted to isolate the cDNA for Ki to elucidate
the structure and function of this antigen, and establish enzyme-Iinked-im-
munosorbent-assay (ELISA) for anti-Ki antibodies using recombinant-antigen.
A cDNA clone (pb-Ki-1) for the Ki antigen was isolated from a cDNA library
of bovine retina by using anti-Ki serum obtained from lupus patients. Using pb-
Ki-1 as a probe, human full-length Ki cDNA clone (Ah-Ki-10) was also isolated
from a agtl 1 libraly of placenta mRNA. The sequence predicted a protein of 254
amino acids (M. W. 29508) with highly hydrophilic and weakly acidic characters.
The purified bacterial product of pb-Ki (b-Na-X) was specifically reacted with an-
ti-Ki sera in double immunodiffusion and immunoblotting and reactions were
specifically inhibited by adsorption both with b-NA-X and Ki antigen purified
from rabbit thymus extract.
Using b-NA-X as an antigen, ELISA for anti-Ki antibodies was established,
Fifty pl (lOpl/ml) of antigen solution was added to a well of Immunoplate II
(Nunc) to coat the antigen, and after sera (1:300) were reacted, reactions were
detected by alkaline phosphatase labeled anti-human IgG. This system was
specifically reacted with anti-Ki standard sera. When sera from patients with
various rheumatic diseases were tested, anti-Ki antibodies were frequently
detected in patients with lupus (14.4% out of 111) compared with patients with
other dieseases (PSS 3.3%, PM/DM 6.6%, RA 6.0%, SjS 4.0%). In SLE, the fre-
quencies of pericarditis and pleuritis were significantly high in patients with anti-
Ki. Those results suggested that ELISA using recombinant Ki antigen was useful
for the diagnosis of lupus reacting with anti-Ki antibodies specifically.
117
Molecular Cloning of Ki Antigen C DNA and Enzyme-Linked-
Immunosorbent-Assay for Anti-Ki Using Recombinant Ki
Y. Takasaki1, M. Shibata2, K. Shimada3, T. Nikaidou3, Y. Nishida3,
M. Sakamoto1, H. Hashimoto1, and S. Hirose 1
'Juntendo University, Tokyo 113,
2 Med. Bio. Lab.
3Aichi Cancer Center, Nagoya, Japan
In 1981, TOJO et al. firstly reported anti-Ki antibody and showed its clinical
significance in lupus patients. But the characteristics of Ki antigen have not been
well defined. In this report, we attempted to isolate the cDNA for Ki to elucidate
the structure and function of this antigen, and establish enzyme-Iinked-im-
munosorbent-assay (ELISA) for anti-Ki antibodies using recombinant-antigen.
A cDNA clone (pb-Ki-1) for the Ki antigen was isolated from a cDNA library
of bovine retina by using anti-Ki serum obtained from lupus patients. Using pb-
Ki-1 as a probe, human full-length Ki cDNA clone (Ah-Ki-10) was also isolated
from a agtl 1 libraly of placenta mRNA. The sequence predicted a protein of 254
amino acids (M. W. 29508) with highly hydrophilic and weakly acidic characters.
The purified bacterial product of pb-Ki (b-Na-X) was specifically reacted with an-
ti-Ki sera in double immunodiffusion and immunoblotting and reactions were
specifically inhibited by adsorption both with b-NA-X and Ki antigen purified
from rabbit thymus extract.
Using b-NA-X as an antigen, ELISA for anti-Ki antibodies was established,
Fifty pl (lOpl/ml) of antigen solution was added to a well of Immunoplate II
(Nunc) to coat the antigen, and after sera (1:300) were reacted, reactions were
detected by alkaline phosphatase labeled anti-human IgG. This system was
specifically reacted with anti-Ki standard sera. When sera from patients with
various rheumatic diseases were tested, anti-Ki antibodies were frequently
detected in patients with lupus (14.4% out of 111) compared with patients with
other dieseases (PSS 3.3%, PM/DM 6.6%, RA 6.0%, SjS 4.0%). In SLE, the fre-
quencies of pericarditis and pleuritis were significantly high in patients with anti-
Ki. Those results suggested that ELISA using recombinant Ki antigen was useful
for the diagnosis of lupus reacting with anti-Ki antibodies specifically.