1989 Fiscal Year Final Research Report Summary
THE MOLECULAR BIOLOGICAL STUDY OF THE RELATIONSHIP BETWEEN THE ACTIVE STAGE OF CHRONIC HEPATITIS B AND THE MUTATION OF THE HEPATITIS B VIRUS
| Project/Area Number |
63480203
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Gastroenterology
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| Research Institution | Ehime University |
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Principal Investigator |
OHTA Yasuyuki Professor of Medicine, Ehime University, 医学部, 教授 (40033055)
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| Co-Investigator(Kenkyū-buntansha) |
HORIIKE Norio Assistant Instructor of Medicine, Ehime University, 医学部, 助手 (90173624)
MICHITAKA Kojiro Assistant Instructor of Medicine, Ehime University, 医学部附属病院, 助手 (50209798)
ONJI Morikazu Lecturer of Medicine, Ehime University, 医学部附属病院, 講師 (10112260)
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| Project Period (FY) |
1988 – 1989
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| Keywords | HBVDNA / PGR(Polymerase chain reaction) / Mutation |
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| Research Abstract |
We have reported that the presence of sublobular necrosis of the hepatocytes is important in the progress of chronic hepatitis to liver cirrhosis. It has been evident that the necrosis is caused by the immunological response of the host to the hapatocytes infected by hepatitis B virus (HBV). But it has not been clear why the necrosis of hepatocytes are repeated even if the HBV-infected hepatocytes are cleared once.
We report here, the result of the study of the presence of mutation at the C region of a HBV clone in cases of chronic active hepatitis B, and the HBV clone with the stop codon at amino acid position 28 in the precore region of HBVDNA is prominently present in the serum of some of HBeAg-positive patients. Four serum samples from two patients with chronic hepatitis B were examined for the cloning or HBV. Serum samples were collected before and after seroconversion. from HBeAg to anti-HBe in one patient, and at two different Points in the HBeAg-positive stage of another patient. DNA was extracted from 370ul of serum by the alkaline lysis method, and HBVDNA fragment was amplified by PCR (Polymerase Chain reaction). Amplified fragments were inserted into a pUC vector, and 4 independent clones possessing HBVDNA were isolated, the sequences of which were determined by the dideoxy chain termination method. In the two patients there are no mutations before and after the elevation or the transaminase, but the stop codon at the precore region was present in all 12 clones derived from the HBeAg- Positive stages of both patients, and also in all 4 clones derived from the anti-HBe-positive stage of the first patient.
These results suggest that mutant HBV with the stop codon, and Wild-type HBV coexist and that a small population of wild-type HBV among a large population of mutant HBV was producing in our cases.
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Research Products
(2 results)
