单克隆抗体识别的癌胚抗原决定簇及其生化特性

CARCINOEMBRYONIC ANTIGENS DEFINED BY A PANEL OF MONOCLONAL ANTIBODIES AND THEIR BIOCHEMICAL CHARACTERISTICS

本文应用系列抗CEA及相关抗原的单抗系列,探测了其抗原决定簇、生化特性及抗体反应的特异性。并以物理、化学因素处理、鉴定了抗原的化学稳定性及相关结构。以亚细胞膜结合-微量固相放免分析试验,分析了此系列单抗与结直肠癌组织细胞反应的限定性。

Epitope domains and biochemical characteristics in Carcinoembryonic antigen were identified by a panel of monoclonal antibodies, 7 anti-CEA, 2 anti-blocd group substance Lewisy and H type-2 and 2 anti-epidermal growth factor receptor antibodies. Of 7 anti-CEA to mcncclenal antibodies, the first 5 were reactive only to CEA, while the remaining 2 antibodies reacted epitopes commonly expressed on CEA and the normal cross-reacting antigen, NCA. CEA-associated epitopes were identified, 2 independent epitopes by antibodies 1, 5, antibodies 2, 3, 4, 6, 7 defined a series of conformation-indenpendent epitopes which were topographically closely related to the CEA molecule. We also found Lewisy epitope in CEA molecule defined by antibody C_(14) (specific to Lewisy antigen) . CEA Treatcd with physical and chemical reagents the chemical stabilityand covespadnig strueture of CEA were idenfified. The activity of CEA was resistant to heating and aldehyde fix fluid, epitopes of CEA defined by 4 antibodies were sensitive to reduction and alkylation which indicated theyr were related to disulphide bond. ENM-binding micro-RIA test showed a panel of monoclonal antibodies was specifically reacted to colorectal cancer. These data provided a basis for application in diagnosis and immunotherapy.