Presentation of two epitopes of the preS2 region of hepatitis B virus on live recombinant bacteria.
Presentation of two epitopes of the preS2 region of hepatitis B virus on live recombinant bacteria.
复制标题
乙型肝炎病毒 preS2 区域的两个表位在活重组细菌上的呈现。
作者：
A. Charbit;E. Sobczak;M. Michel;A. Molla;P. Tiollais;M. Hofnung
我们已经开发了一种基因程序，通过使用外膜LamB蛋白作为载体，在大肠杆菌表面暴露外源表位，我们应用该程序表达B型肝炎病毒前S2区的两个不同部分：A区，残基132-145，和B区，残基153-171。所获得的杂交蛋白（LamB-preS 2 A和LamB-preS 2 B）在大肠杆菌中正常表达、稳定，并保留了LamB的大部分生物学功能。将相应的菌株直接作为免疫原接种家兔和小鼠。发现两种病毒序列在两种动物种属中均具有免疫原性。使用LamB-preS 2 A，诱导的抗体能够与病毒颗粒和固定化肽反应。对于LamB-preS 2 B，产生的抗体不能识别固定的肽。然而，结果表明，插入LamB中的B表位在产生抗病毒抗体方面至少与相应的合成肽一样有效。因此，LamB的表位呈递可呈现免疫优势。我们还表明，肽A是聚合的人血清白蛋白受体的重要组成部分。这些结果进一步验证了LamB载体系统的表位呈递，提供了关于表达的两个肝炎B区域的信息。
Having developed a genetic procedure to expose a foreign epitope at the surface of Escherichia coli by using the outer membrane LamB protein as a carrier, we apply this procedure to express two distinct portions of the preS2 region of hepatitis B virus: region A, residues 132-145, and region B, residues 153-171. The resulting hybrid proteins (LamB-preS2 A and LamB-preS2 B) were normally expressed, stable, and still kept most biologic functions of LamB. The corresponding bacterial strains were used directly as immunogens in rabbits and mice. Both viral sequences were found to be immunogenic in the two animal species. With LamB-preS2 A, antibodies induced were able to react with the viral particles and the immobilized peptide. With LamB-preS2 B, the antibodies raised were not able to recognize the immobilized peptide. However, the results suggest that the B epitope, inserted in LamB, was at least as efficient as the corresponding synthetic peptide in raising antiviral antibodies. Thus, epitope presentation with LamB may present advantages for immunization. We also have shown that peptide A is an essential part of the polymerized human serum albumin receptor. These results, which validate further the LamB vector system for epitope presentation, provide information on the two hepatitis B regions expressed.