Hapten optimization for cocaine vaccine with improved cocaine recognition.
Hapten optimization for cocaine vaccine with improved cocaine recognition.
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优化可卡因疫苗的合粒，提高可卡因识别率。
DOI：
10.1111/cbdd.12326
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发表时间：
2014-09
影响因子：
3
通讯作者：
Orson FM
中科院分区：
文献类型：
--
作者：
Ramakrishnan M;Kinsey BM;Singh RA;Kosten TR;Orson FM
在缺乏任何有效治疗可卡因成瘾的药物疗法的情况下，免疫疗法作为一种治疗干预措施正在积极推行。虽然已经探索了几种不同的可卡因半抗原来开发抗可卡因抗体，但没有成功设计出具有生理条件下天然可卡因中发现的质子化托烷氮的半抗原，包括已在 II 期临床试验中进行测试的琥珀酰去甲可卡因 (SNC) 半抗原。在此，我们讨论三种不同的可卡因半抗原：己基去甲可卡因（HNC）、溴乙酰氨基丁基去甲可卡因（BNC）和琥珀酰丁基去甲可卡因（SBNC），每种半抗原都具有模仿天然可卡因的叔氮结构，可以优化抗可卡因抗体的特异性，从而更好地识别可卡因。用这些与免疫原性蛋白缀合的半抗原免疫的小鼠产生了高滴度的抗可卡因抗体。然而，在 HNC 和 BNC 半抗原与载体蛋白化学缀合的过程中，2β 甲酯基团被水解，并且用这些缀合物疫苗对小鼠进行免疫接种，小鼠体内产生了结合可卡因和无活性苯甲酰爱康宁代谢物的抗体。而在 SBNC 结合疫苗的情况下，似乎没有发生甲酯水解，导致抗体对可卡因比 BE 具有更高的特异性。尽管我们观察到 SNC 半抗原具有类似的特异性，但显着的区别是 SBNC 在托烷氮原子上带有正电荷，因此预计它对可卡因有更好的结合。当使用各自的半抗原-BSA作为底物时，SBNC抗体（2.8μM）的50％可卡因抑制浓度（IC50）值明显优于SNC抗体（9.4μM）。此外，两种血清的抗体对BE均无抑制作用。与 BNC 和 HNC 相比，SBNC 缀合物在 4°C 下保持几个月，在 37°C pH 10 缓冲液中保持 2-3 天也高度稳定，没有任何明显的水解。
In the absence of any effective pharmacotherapy for cocaine addiction, immunotherapy is being actively pursued as a therapeutic intervention. While several different cocaine haptens have been explored to develop anti-cocaine antibodies, none of the hapten was successfully designed which had a protonated tropane nitrogen as is found in native cocaine under physiological conditions, including the succinyl norcocaine (SNC) hapten that has been tested in phase II clinical trials. Herein, we discuss three different cocaine haptens: hexyl-norcocaine (HNC), bromoacetamido butyl- norcocaine (BNC), and succinyl-butyl- norcocaine (SBNC), each with a tertiary nitrogen structure mimicking that of native cocaine which could optimize the specificity of anti-cocaine antibodies for better cocaine recognition. Mice immunized with these haptens conjugated to immunogenic proteins produced high titer anti-cocaine antibodies. However, during chemical conjugation of HNC and BNC haptens to carrier proteins, the 2β methyl ester group is hydrolyzed and immunizing mice with these conjugate vaccines in mice produced antibodies that bound both cocaine and the inactive benzoylecgonine metabolite. While in the case of the SBNC conjugate vaccine hydrolysis of the methyl ester did not appear to occur, leading to antibodies with high specificity to cocaine over BE. Though we observed similar specificity with a SNC hapten, the striking difference is that SBNC carries a positive charge on the tropane nitrogen atom, and therefore it is expected to have better binding of cocaine. The 50% cocaine inhibitory concentration (IC50) value for SBNC antibodies (2.8 μM) was significantly better than the SNC antibodies (9.4 μM) when respective hapten-BSA was used as a substrate. In addition, antibodies from both sera had no inhibitory effect from BE. In contrast to BNC and HNC, the SBNC conjugate was also found to be highly stable without any noticeable hydrolysis for several months at 4°C and 2-3 days in pH 10 buffer at 37°C.