Simultaneous expression of the S and L surface antigens of hepatitis B, and formation of mixed particles in the methylotrophic yeast, Hansenula polymorpha
Simultaneous expression of the S and L surface antigens of hepatitis B, and formation of mixed particles in the methylotrophic yeast, Hansenula polymorpha
复制标题
甲基营养酵母多形汉逊酵母中乙型肝炎 S 和 L 表面抗原的同时表达和混合颗粒的形成
作者：
Z. Janowicz;K. Melber;A. Merckelbach;E. Jacobs;N. Harford;M. Comberbach;C. Hollenberg
已经为甲基营养酵母多形汉逊酵母开发了一个表达系统，用于在源自甲醇氧化酶和甲酸脱氢酶基因的强甲醇诱导型启动子的控制下共表达 L (preS1-S2-S) 和 S 型乙型肝炎表面抗原 (HBsAg)。该多形多形菌表达系统的一个独特特征是可以通过多聚体整合机制整合多达 100 个表达盒拷贝。构建了包含不同数量的L和S表达盒的几种多聚体整合体，以给出以不同L与S比率为特征的菌株谱。 S抗原的表达水平为可溶性细胞总蛋白的5-8%。通过蔗糖和 CsCl 密度梯度离心以及颗粒特异性免疫分析进行的分析表明，合成的 HBsAg 自发组装成含有 S 和 L 蛋白的复合亚病毒颗粒。仅发现一小部分 L 蛋白被糖基化。这些源自地精的复合颗粒可用于生产乙型肝炎病毒疫苗，由于存在更广泛的表位和可忽略的糖基化，因此具有改善免疫原性的潜力。
An expression system has been developed for the methylotrophic yeast Hansenula polymorpha and used to co‐express both the L (preS1‐S2‐S) and S hepatitis B surface antigens (HBsAg) under the control of strong methanol‐inducible promoters derived from the methanol oxidase and from the formate dehydrogenase genes. A unique feature of this H. polymorpha expression system is the possibility of integrating up to 100 copies of an expression cassette via a multimeric integration mechanism. Several multimeric integrants containing various numbers of L and S expression cassettes were constructed to give a spectrum of strains characterized by different L to S ratios. The expression level of S antigen was 5–8% of the total soluble cell protein. Analysis by sucrose and CsCl density gradient centrifugation and by particle‐specific immunoassays demonstrated that the synthesized HBsAg spontaneously assembled into composite subviral particles containing both S and L proteins. Only a minor portion of the L protein was found to be glycosylated. These H. polymorpha‐derived composite particles can be used for the production of a hepatitis B virus vaccine with the potential for improved immunogenicity due to the presence of a wider spectrum of epitopes and negligible glycosylation.