In order to investigate peptide mimics of carbohydrate blood group A antigen, a phage display 12-mer peptide library was screened with a monoclonal antibody against blood group A antigen, NaM87-1F6. The antibody-bindi...In order to investigate peptide mimics of carbohydrate blood group A antigen, a phage display 12-mer peptide library was screened with a monoclonal antibody against blood group A antigen, NaM87-1F6. The antibody-binding properties of the selected phage peptides were evaluated by phage ELISA and phage capture assay. The peptides were co-expressed as glutathione S-transferase （GST） fusion proteins. RBC agglutination inhibition assay was performed to assess the natural blood group A antigen-mimicking ability of the fusion proteins. The results showed that seven phage clones selected bound to NaM87-1F6 specifically, among which, 6 clones bore the same peptide sequence, EYWYCGMNRTGC and another harbored a different one QIWYERTLPFTF. The two peptides were successfully expressed at the N terminal of GST protein. Both of the fusion proteins inhibited the RBC agglutination mediated by anti-A serum in a concentration-dependent manner. These results suggested that the fusion proteins based on the selected peptides could mimic the blood group A antigen and might be used as anti-A antibody-adsorbing materials when immunoabsorption was applied in ABO incompatible transplantation.展开更多
In the past five years, the therapy of colorectal carcinoma by mouse monoclonal antibody (mAb) 17 1A has proven that the tumour associated antigen (17 1A antigen) recognized by mAb 17 1A serves as a useful antigen in...In the past five years, the therapy of colorectal carcinoma by mouse monoclonal antibody (mAb) 17 1A has proven that the tumour associated antigen (17 1A antigen) recognized by mAb 17 1A serves as a useful antigen in the detection of tumor cells and adjuvant therapy of colorectal carcinoma. In this study, we investigated modulation of 17 1A antigen expression by human interferon α (IFN α) using flow cytometry analysis. IFN α enhances 17 1A antigen expression on HT 29 cell surfaces by about 40%. Using M79 sepharose column (M79: mouse mAb to 17 1A antigen), a protein (p33) with a relative molecular mass of 3 3×10 4 was isolated from HT 29 and HCT (colon carcinoma cell lines) by affinity chromatography analysis and SDS PAGE under reducing and non reducing conditions. P33 was identified as 17 1A antigen by silver staining and ELISA assay. The antibodies 17 1A and M79 could recognize the protein p33. These results indicate that HT29 and HCT cell lines all express a relative molecular mass of 3 3×10 4 tumor associated antigen whose expression could be up modulated by human IFN α.展开更多
The tumor-associated antigen Ep-CAM (17-1A antigen), defined by the murine monoclonal antibody (mAb) 17-1A, has been identified as a 42-kD glycoprotein. The mAb 17-1A has been used for immunotherapy of colorectal can...The tumor-associated antigen Ep-CAM (17-1A antigen), defined by the murine monoclonal antibody (mAb) 17-1A, has been identified as a 42-kD glycoprotein. The mAb 17-1A has been used for immunotherapy of colorectal cancer. We obtained mAb 19F4 using a synthetic peptide containing antigen determinants of 17-1A antigen. The mAb 19F4 can bind the corresponding dominants of the 17-1A antigen in ELISA. Western-blot analysis demonstrated that mAb 19F4 recognized a 50-kD protein from cell lysates of MCF-7 (breast cancer cell line). Both mAb 19F4 and 17-1A detected a 42-kD protein in the cell lysates of HT-29 (colorectal cancer cell line). The results suggest that new members of the tumor-associated antigen family 17-1A may exist.展开更多
A is a tumor associated antigen. Monoclonal antibody (mAb) against 17 1A has been used in adjuvant therapy of colorectal carcinoma. Using mAb against 17 1A antigen on affinity chromatography, a novel putative tumor ...A is a tumor associated antigen. Monoclonal antibody (mAb) against 17 1A has been used in adjuvant therapy of colorectal carcinoma. Using mAb against 17 1A antigen on affinity chromatography, a novel putative tumor associated antigen (P50) whose relative molecular mass is 5 0×10 4 has been isolated from human colorectal tumor tissues which are recognized by mAbs 17 1A and M79, while the relative molecular mass of 17\|1A antigen isolated from several colorectal tumor cell lines is 3 3×10 4. P50 was recognized by mAbs 17 1A and M79 which are specific mAbs against 17 1A antigen.展开更多
文摘In order to investigate peptide mimics of carbohydrate blood group A antigen, a phage display 12-mer peptide library was screened with a monoclonal antibody against blood group A antigen, NaM87-1F6. The antibody-binding properties of the selected phage peptides were evaluated by phage ELISA and phage capture assay. The peptides were co-expressed as glutathione S-transferase （GST） fusion proteins. RBC agglutination inhibition assay was performed to assess the natural blood group A antigen-mimicking ability of the fusion proteins. The results showed that seven phage clones selected bound to NaM87-1F6 specifically, among which, 6 clones bore the same peptide sequence, EYWYCGMNRTGC and another harbored a different one QIWYERTLPFTF. The two peptides were successfully expressed at the N terminal of GST protein. Both of the fusion proteins inhibited the RBC agglutination mediated by anti-A serum in a concentration-dependent manner. These results suggested that the fusion proteins based on the selected peptides could mimic the blood group A antigen and might be used as anti-A antibody-adsorbing materials when immunoabsorption was applied in ABO incompatible transplantation.
文摘In the past five years, the therapy of colorectal carcinoma by mouse monoclonal antibody (mAb) 17 1A has proven that the tumour associated antigen (17 1A antigen) recognized by mAb 17 1A serves as a useful antigen in the detection of tumor cells and adjuvant therapy of colorectal carcinoma. In this study, we investigated modulation of 17 1A antigen expression by human interferon α (IFN α) using flow cytometry analysis. IFN α enhances 17 1A antigen expression on HT 29 cell surfaces by about 40%. Using M79 sepharose column (M79: mouse mAb to 17 1A antigen), a protein (p33) with a relative molecular mass of 3 3×10 4 was isolated from HT 29 and HCT (colon carcinoma cell lines) by affinity chromatography analysis and SDS PAGE under reducing and non reducing conditions. P33 was identified as 17 1A antigen by silver staining and ELISA assay. The antibodies 17 1A and M79 could recognize the protein p33. These results indicate that HT29 and HCT cell lines all express a relative molecular mass of 3 3×10 4 tumor associated antigen whose expression could be up modulated by human IFN α.
基金Supported by the National Key Basic Research SpecificFunds(No.G19990 75 60 7) and the National ScienceFoundation for Outstanding Young Scientist of China(No.3 0 0 2 5 0 3 8)
文摘The tumor-associated antigen Ep-CAM (17-1A antigen), defined by the murine monoclonal antibody (mAb) 17-1A, has been identified as a 42-kD glycoprotein. The mAb 17-1A has been used for immunotherapy of colorectal cancer. We obtained mAb 19F4 using a synthetic peptide containing antigen determinants of 17-1A antigen. The mAb 19F4 can bind the corresponding dominants of the 17-1A antigen in ELISA. Western-blot analysis demonstrated that mAb 19F4 recognized a 50-kD protein from cell lysates of MCF-7 (breast cancer cell line). Both mAb 19F4 and 17-1A detected a 42-kD protein in the cell lysates of HT-29 (colorectal cancer cell line). The results suggest that new members of the tumor-associated antigen family 17-1A may exist.
基金the Ministry of Education of China !(No .1 996 4 6 6 )
文摘A is a tumor associated antigen. Monoclonal antibody (mAb) against 17 1A has been used in adjuvant therapy of colorectal carcinoma. Using mAb against 17 1A antigen on affinity chromatography, a novel putative tumor associated antigen (P50) whose relative molecular mass is 5 0×10 4 has been isolated from human colorectal tumor tissues which are recognized by mAbs 17 1A and M79, while the relative molecular mass of 17\|1A antigen isolated from several colorectal tumor cell lines is 3 3×10 4. P50 was recognized by mAbs 17 1A and M79 which are specific mAbs against 17 1A antigen.
