1994 Fiscal Year Final Research Report Summary
Gene cloning of 40kD and its functional analysis in ulcerative colitis.
| Project/Area Number |
05670489
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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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 assistaht Professor, 医学部, 講師 (00196081)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Yaso Sapporo Medical University.faculty, 医学部, 助手 (10236325)
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| Project Period (FY) |
1993 – 1994
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| Keywords | ulcerative colitis / anti-colon antibody / 40kD protein / tropomyosin / ADCC / MHC-class ll Ag / HLA-DP / mechanism of colonic mucosa injuray |
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| Research Abstract |
We have previously reported that circulating antibody against 40 kD colonic antigen are present in the sera of patients with ulcerative colitis (UC). Recently the sequence of tryptic peptide of 40kD protein has been proved to correspond to tropomyosin (TM). In this study, we investigated the anti-TM antibody titer in patients with UC by a new ELISA method using porcine TM for coating antigen. And whether these antibody causes antibody dependent cell mediated cytotoxicity (ADCC) against RPM14788 cells established from colon cancer patient.
If TM is a target molecule for ADCC antibody, TM must be expressed in the surface of target cells. So we investigated the interaction of TM peptides with HLA class ll molecules using HLA-DP,DQ,DR gene transfected mouse fibroblasts (L-cell) by FACS.The tesults we obtainel were as follows ;
1.In active phase of UC patients, anti-TM antibody titer was high and causes ADCC These ADCC activities of UC sera were reduced when the sera were preincubated with TM.
2.TM and HLA class ll (DP) antigens were expressed in the surface of RPM14788 cells when examined by FACS.
3.TM peptide was bound not with DQ or DR expressed L cells but with DP expressed L cells.
In conclusion, TM antigen was expressed on the surface of ADCC target cells in association with HLA-DP molecule and must be a target molecule for ADCC in UC patients.
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