1996 Fiscal Year Final Research Report Summary
Significance of Tropomyosin peptide
| Project/Area Number |
07670604
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Gastroenterology
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| Research Institution | Sapporo Medical University |
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Principal Investigator |
SAKAMAKI Sumio Sapporo Medical University School of Medicine, 4th Department of Internal Medicine, Assistant Professor, 医学部, 講師 (00196081)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Yasuo Sapporo Medical University School of Medicine, 4th Department of Internal Medici, 医学部, 助手 (10236325)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Ulcerative colitis / Tropomyosin / HLA-class II / HLA-DPw9 / ADCC / Peptide / ELISA / Epitope |
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| Research Abstract |
Recent studies suggest that autoimmune mechanism are involved in the pathogenesis of ulcerative colitis (UC). We have previously reported that auto antibodies in sera of patients with UC in active stage recognize Tropomyosin (TM) peptides expressed on a cell surface, which are associated with HLA-DPw9 molecule.
In this study, we aimed to analyze the TM peptide associated with HLA-DPw9 molecule. (1) The search for the homology sequence of TM peptide with the epitopes, which were recognized by Immunoglobulins already reported, was conducted using MPsrch data. The particular sequence (HIAED ADRK) of TM peptide, which was found to have a 88.9% homology to the IgE binding epitope in patients with shrimp allergy, was obtained as a candidate of the peptides associated with HLA-DPw9. (2) We newly synthesized this peptide (HIAED ADRK) and the presence of auto antibodies to this 9 mer peptide was investigated by ELISA using this synthetic peptide as antigen. Antibodies are present in sera of patients with UC (1.23(]SY.+-。[)0.4) but not in sera of healthy volunteers (0.40(]SY.+-。[)0.10) or CD (0.52(]SY.+-。[)0.21). (3) To examine if this 9 mer peptide is involved in ADCC,the UC sera, before and after absorption with this peptide, were used for ADCC assay with HLA-DPw9 gene transfected L-cells as a target. ADCC activity of UC sera (15.4(]SY.+-。[)6.5%) was significantly higher than that of normal volunteers (4.11(]SY.+-。[)0.52%) (p<0.05) and it was significantly reduced when the sera were absorbed with the peptides (5.98(]SY.+-。[)2.11%) (p<0.05). With these data, we surmised that synthetic peptide (HIAED ADRK) is presumably the one of responsive epitope (s) associated with HLA.
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