Belisle B W, Twiddy E M, Holmes R K
Infect Immun. 1984 Dec;46(3):759-64. doi: 10.1128/iai.46.3.759-764.1984.
Nine selected hybridoma cell lines that produced monoclonal antibodies against the heat-labile enterotoxin encoded by a plasmid from an Escherichia coli strain of human origin (LTh) were characterized. Hybridomas that produced anti-LTh antibodies with previously unrecognized specificities or reactivities were selected for cloning. Each monoclonal antibody was tested for isotype and for binding to LTh holotoxin, the A and B subunits derived from LTh (LTh-A and LTh-B), holotoxin encoded by a plasmid from an E. coli strain of porcine origin (LTp), and cholera enterotoxin (CT). Binding was also tested in Western blots with the following antigens: pentameric LTh-B, monomeric LTh-B, LTh-A, and the A1 and A2 fragments produced from LTh-A by treatment with trypsin. These monoclonal anti-LTh antibodies and selected anti-LTh and anti-CT monoclonal antibodies described previously were tested for neutralization of LTh, LTp, and CT. Five of the nine new monoclonal antibodies gave detectable cross-reactions with LTp and CT. Four reacted with determinants of LTh that were not present on CT; one of these four did not react with LTp and was specific for a unique epitope of LTh. Three antibodies were specific for LTh-B. All three reacted with pentameric LTh-B, but only one reacted in Western blots with monomeric LTh-B. Six antibodies were specific for LTh-A. Three reacted in Western blots with LTh-A and its A1 fragment; the other three did not react in Western blots. All nine of the new monoclonal antibodies neutralized LTh but not CT; the eight that cross-reacted with LTp in binding assays also neutralized LTp. Of four neutralizing anti-CT monoclonal antibodies that bound to LTh, none had significant neutralizing activity against LTh.
对九株筛选出的杂交瘤细胞系进行了特性鉴定，这些细胞系可产生针对源自人源大肠杆菌菌株质粒编码的不耐热肠毒素（LTh）的单克隆抗体。选择产生具有先前未识别的特异性或反应性的抗LTh抗体的杂交瘤进行克隆。对每种单克隆抗体进行了亚型检测，并检测其与LTh全毒素、源自LTh的A和B亚基（LTh-A和LTh-B）、源自猪源大肠杆菌菌株质粒编码的全毒素（LTp）以及霍乱肠毒素（CT）的结合情况。还在蛋白质免疫印迹中用以下抗原检测结合情况：五聚体LTh-B、单体LTh-B、LTh-A以及用胰蛋白酶处理LTh-A产生的A1和A2片段。对这些新的抗LTh单克隆抗体以及先前描述的选定抗LTh和抗CT单克隆抗体进行了LTh、LTp和CT中和试验。九种新单克隆抗体中有五种与LTp和CT产生了可检测到交叉反应。四种与CT上不存在的LTh决定簇发生反应；这四种中的一种不与LTp反应，对LTh的一个独特表位具有特异性。三种抗体对LTh-B具有特异性。这三种都与五聚体LTh-B反应，但在蛋白质免疫印迹中只有一种与单体LTh-B反应。六种抗体对LTh-A具有特异性。三种在蛋白质免疫印迹中与LTh-A及其A1片段反应；另外三种在蛋白质免疫印迹中不反应。所有九种新单克隆抗体都能中和LTh但不能中和CT；在结合试验中与LTp交叉反应的八种也能中和LTp。在与LTh结合的四种中和抗CT单克隆抗体中，没有一种对LTh具有显著中和活性。
