A Recombinant Humanized Anti-Cocaine Monoclonal Antibody Inhibits the Distribution of Cocaine to the Brain in Rats
A Recombinant Humanized Anti-Cocaine Monoclonal Antibody Inhibits the Distribution of Cocaine to the Brain in Rats
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DOI：
10.1124/dmd.114.057034
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发表时间：
2014-07-01
影响因子：
3.9
通讯作者：
Ball, William J.
中科院分区：
文献类型：
--
作者：
Norman, Andrew B.;Gooden, Felicia C. T.;Ball, William J.
单克隆抗体（mAb）h2 E2是嵌合人/鼠抗可卡因mAb 2 E2的人源化版本。重组h2 E2蛋白在体外从转染的哺乳动物细胞系中产生，并保留高亲和力（4 nM Kd）和特异性可卡因超过其非活性代谢物苯甲酰芽子碱（BE）和芽子碱甲酯。在大鼠中，h2 E2（120 mg/kg i. v.）终末消除半衰期较长，为9.0天，稳态分布容积（V-dss）较低，为0.3 l/kg。用h2 E2预处理产生了血浆可卡因浓度-时间曲线（AUC）下的面积的8.8倍的急剧增加，并且在脑中，在静脉内注射等摩尔可卡因剂量后可卡因的AUC同时降低68%。通过可卡因的V-dss的减少显示的通过h2 E2在血浆中的可卡因的螯合指示潜在的临床功效。尽管可卡因与血浆中h2 E2的结合应抑制分布和代谢，但可卡因的消除仍是多室的，尽管存在h2 E2，但仍从血浆中快速消除。BE是可卡因的主要代谢物，脑BE浓度比血浆高6倍，表明可卡因通常在脑中代谢。在h2 E2的存在下，脑BE浓度降低，血浆BE增加，与观察到的可卡因处置的h2 E2诱导的变化一致。可卡因分布到大脑的抑制证实了人源化mAb h2 E2作为开发可卡因滥用免疫疗法的主要候选物。
The monoclonal antibody (mAb), h2E2, is a humanized version of the chimeric human/murine anti-cocaine mAb 2E2. The recombinant h2E2 protein was produced in vitro from a transfected mammalian cell line and retained high affinity (4 nM K-d) and specificity for cocaine over its inactive metabolites benzoylecgonine (BE) and ecgonine methyl ester. In rats, pharmacokinetic studies of h2E2 (120 mg/kg i.v.) showed a long terminal elimination half-life of 9.0 days and a low volume of distribution at steady state (V-dss) of 0.3 l/kg. Pretreatment with h2E2 produced a dramatic 8.8-fold increase in the area under the plasma cocaine concentration-time curve (AUC) and in brain a concomitant decrease of 68% of cocaine's AUC following an i.v. injection of an equimolar cocaine dose. Sequestration of cocaine in plasma by h2E2, shown via reduction of cocaine's V-dss, indicates potential clinical efficacy. Although the binding of cocaine to h2E2 in plasma should inhibit distribution and metabolism, the elimination of cocaine remained multicompartmental and was still rapidly eliminated from plasma despite the presence of h2E2. BE was the major cocaine metabolite, and brain BE concentrations were sixfold higher than in plasma, indicating that cocaine is normally metabolized in the brain. In the presence of h2E2, brain BE concentrations were decreased and plasma BE was increased, consistent with the observed h2E2-induced changes in cocaine disposition. The inhibition of cocaine distribution to the brain confirms the humanized mAb, h2E2, as a lead candidate for development as an immunotherapy for cocaine abuse.