[Mimic epitope recognized by monoclonal antibody MG7 against gastric cancer through screening phage displayed random peptide library].
OBJECTIVE
To get mimic peptide epitopes that could be recognized by a monoclonal antibody against gastric cancer named MG7 from random peptide library displayed by phage, and to provide useful information for further study of the interaction between antigen and antibody.


METHODS
Through affinity enrichment and immunoscreening of two phage-displayed non-apeptide libraries constructed in pVIII with MG7 MAb separately, several positive phages were obtained. Fluorescence labeling and dot blot were carried out for further identification of their binding activities. Then, some of the positive phages were sequenced and their corresponding peptide sequence was deduced according to their DNA sequence. Finally, HLA binding prediction software was applied for HLA binding analysis.


RESULTS
Based on several rounds of screening and binding activity detection, we got twelve and thirty positive phage clones respectively from two libraries. Through DNA sequencing, peptide deducing and sequence aligning analysis of the positive phages, some preserved epitope information such as PLX(0 - 2)S, SAVR, XRMX and YARN were obtained. The prediction using HLA binding analysis software showed that most of the sequenced peptide had the potentiality to bind with HLA molecules.


CONCLUSIONS
PLX(0 - 2)S, SAVR, XRMX and YARN may be some of the motifs which could be recognized by monoclonal antibody MG7.
Xu
L
L
Institute of Digestive Diseases, Xijing Hospital, The 4th Military Medical University, Xi'an 710032, China.
Qiao
T
T
Chen
B
B
D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000235:genetics / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D001435:Bacteriophages / Q000276:immunology; D004247:DNA / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D004926:Escherichia coli / Q000821:virology; D005455:Fluorescent Antibody Technique; D019151:Peptide Library; D013274:Stomach Neoplasms / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D018985:Epitopes, B-Lymphocyte; D019151:Peptide Library; D004247:DNA