Mapping PAM4 (clivatuzumab), a monoclonal antibody in clinical trials for early detection and therapy of pancreatic ductal adenocarcinoma, to MUC5AC mucin
Mapping PAM4 (clivatuzumab), a monoclonal antibody in clinical trials for early detection and therapy of pancreatic ductal adenocarcinoma, to MUC5AC mucin
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DOI：
10.1186/1476-4598-12-143
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发表时间：
2013-11-20
期刊：
影响因子：
37.3
通讯作者：
Goldenberg, David M.
中科院分区：
文献类型：
--
作者：
Gold, David V.;Newsome, Guy;Goldenberg, David M.
背景资料：PAM 4是一种与正常胰腺、胰腺良性病变和源自其他组织的癌症相比对胰腺导管腺癌（PDAC）具有高特异性的抗体，正在研究其作为早期检测以及抗体靶向成像和治疗的生物标志物。因此，这种单克隆抗体（MAb）结合的抗原的特性可以提供信息，从而改善抗体的使用。先前的结果表明，该抗原是一种粘蛋白型糖蛋白，富含半胱氨酸二硫键，为PAM 4-epitemia.Methods提供稳定的构象：间接和夹心酶免疫测定（EIA）进行比较和对比的反应性PAM 4与几个抗粘蛋白抗体具有已知的反应性，以特定的粘蛋白物种（例如，例如，在一个实施例中，MUC 1、MUC 4、MUC 5AC等）。研究设计来阻断PAM 4与其特异性抗原的反应性也performed.Results：我们证明，单克隆抗体2-11 M1和45 M1，每一个与MUC 5AC反应，能够在异源夹心免疫测定中提供信号，其中PAM 4是捕获抗体。此外，我们鉴定了MAb 21 M1、62 M1和463 M1，其各自与MUC 5AC反应，抑制PAM 4与其特异性表位的反应。针对MUC 1、MUC 3、MUC 4、MUC 16和CEACAM 6的单克隆抗体不与PAM 4捕获的抗原反应，也不能阻断PAM 4与其抗原的反应。此外，这种认识可以允许通过在该夹心EIA中应用抗MUC 5AC MAb作为探针来改进当前用于检测早期PDAC的基于PAM 4血清的免疫测定。
Background: PAM4, an antibody that has high specificity for pancreatic ductal adenocarcinoma (PDAC), compared to normal pancreas, benign lesions of the pancreas, and cancers originating from other tissues, is being investigated as a biomarker for early detection, as well as antibody-targeted imaging and therapy. Therefore, the identity of the antigen bound by this monoclonal antibody (MAb) can provide information leading to improved use of the antibody. Prior results suggested the antigen is a mucin-type glycoprotein rich in cysteine disulfide bridges that provide stable conformation for the PAM4-epitope.Methods: Indirect and sandwich enzyme immunoassays (EIA) were performed to compare and contrast the reactivity of PAM4 with several anti-mucin antibodies having known reactivity to specific mucin species (e. g., MUC1, MUC4, MUC5AC, etc.). Studies designed to block reactivity of PAM4 with its specific antigen also were performed.Results: We demonstrate that MAbs 2-11 M1 and 45 M1, each reactive with MUC5AC, are able to provide signal in a heterologous sandwich immunoassay where PAM4 is the capture antibody. Further, we identify MAbs 21 M1, 62 M1, and 463 M1, each reactive with MUC5AC, as inhibiting the reaction of PAM4 with its specific epitope. MAbs directed to MUC1, MUC3, MUC4, MUC16 and CEACAM6 are not reactive with PAM4-captured antigen, nor are they able to block the reaction of PAM4 with its antigen.Conclusions: These data implicate MUC5AC as a specific mucin species to which PAM4 is reactive. Furthermore, this realization may allow for the improvement of the current PAM4 serum-based immunoassay for detection of early-stage PDAC by the application of anti-MUC5AC MAbs as probes in this sandwich EIA.