1998 Fiscal Year Final Research Report Summary
ANTI-SELENOCYSTEIN-tRNA ANTIBODIES IN SERA OF AUTOIMMUNE HEPATITIS PATIENTS
Project/Area Number |
09670579
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Gastroenterology
|
Research Institution | JIKEI UNIVERSITY SCHOOL OF MEDICINE |
Principal Investigator |
MATSUFUJI Tamiko JIKEI UNIVERSITY SCHOOL OF MEDICINE,FACULTY OF MEDICINE, 医学部, 講師 (00199845)
|
Project Period (FY) |
1997 – 1998
|
Keywords | autoimmune hepatitis / auto-antibody / autoimmune desease / selenocysteine / tRNA / epitope / enzyme immunoassay |
Research Abstract |
We have found auto-antibodies against selenocysteine (Sec)-tRNA or its complex with proteins in the sera of 5 patients out of 12 autoimmune hepatitis cases (42%). The antibody-positive cases were all female. There was no tendency of age, extent of liver function, occurrences of other auto-antibodies, responses to steroid therapy ; The serum auto-antibodies in the patients did not show quantitative or qualitative changes during the 2-year observation period. Anti-Sec-tRNA antibody was not found in the serum of primary bilirary cirrhosis, auto-immune cholangitis, chronic hepatitis type C patients. Three cases out of 5 anti-Sec-tRNA antibody-positive patients had "direct-type" auto-antibodies which directly recognized in-vitro synthesized radiolabeled human Sec-tRNA.Epitope analysis of the direct-type auto-antibodies revealed that two of them specifically recognized different secondary or tertiary tRNA structures at the D- and TpsiC-loop regions while the other precipitated both Sec-tRNA and Serine-tRNA.Analysis of the "indirect-type" auto-antibodies which only recognized Sec-tRNA-protein complex reacted a protein band of approximately 5OkDa in an extract of human cultured cells. We have developed a non-isotopic assay for the direct-type auto-antibodies by sandwich enzyme immunoassay using biotin-14-CTP-labeled Sec-tRNA as the antigen. In summary we have shown that the occurrence of direct- or indirect-type anti-Sec-tRNA-antibodies is high among AIH patients in Japan. The antibodies recognize variety of epitopes including different regions of Sec-tRNA and a protein bound to Sec-tRNA.
|