不同牛PrP合成肽段的抗原性研究

目的研究PrP多肽的抗原性以及不同偶联方法对多肽免疫原性的影响。方法选择4段牛PrP多肽(BoP1、BoP2、BoP3、BoP4)为半抗原,KLH为载体,MBS、戊二醛两种偶联方法进行偶联,免疫BALB/c小鼠,间接ELISA方法检测小鼠血清中抗体效价,并对两种偶联方法进行比较。结果两组动物均出现死亡,戊二醛偶联多肽免疫小鼠出现不同程度的腹水,MBS偶联多肽免疫小鼠未见其它异常反应;戊二醛偶联的4种多肽产生的抗体效价无显著性差异(P>0.05),MBS偶联的KLH-BoP1、KLH-BoP2、KLH-BoP4产生抗体效价无显著性差异(P>0.05),MBS偶联的KLH-BoP3抗体效价低于其它3种多肽(P<0.05);对同一种多肽而言,不同偶联方法KLH-BoP1、KLH-BoP2、KLH-BoP4所产生抗体效价无显著性差异(P>0.05),戊二醛偶联KLH-BoP3产生的抗体效价明显高于MBS偶联KLH-BoP3产生的抗体效价(P<0.05)。结论PrP多肽可作为半抗原刺激小鼠强烈的免疫反应,不同偶联方法,不同肽段抗原性不同,为抗PrP多克隆及单克隆抗体的制备奠定了基础。

Study on the antigenicity of prion protein peptides

To investigate the antigenicity of prion replication protein (PrP) peptidesand the influence of different coupling methods on the immunogenicity of these peptides, four bovine prion peptides (BoP_l, BoP_2, BoP_3 and BoP_4) were selected as haptens, and the keyhole limpet hemocyanin (KLH) was used as protein carrier. The hapten and carrier were linked by m-maleimidobenzoyi-N-hydroxysuccijnimide ester (MBS) and glutaraldehyde respectively and they were used as antigens to immunize mice. The serum antibody titer of the immunized mice was monitored by indirect ELISA and the antibody titers of mice immunized with antigens coupled with two different methods were compared. It was found that death occurred in both group of mice immunized, in which different degree of ascites appeared in mice immunized with peptides coupled by glutaraldehyde, but there was no abnormalities in mice immunized with peptides coupled by MBS. The titers of antibodies against four peptides were not significantly different in case of glutaraldehyde-coupled antigen, but those were quite different in case of MBS-coupled antigen, however, the titre of antibody against KLH-P_3 was significantly lower than others. For KLH-BoP_l, KLH-BoP_2, and BoP4 peptides, the same antibody titers were found in cases with different coupling methods, but for BOP_3, glutaraldyhyde-coupled antigen could induce higher antibody titer than that of MBS. In conclusion, the prion peptides used as hapten to couple with KLH as protein carrier can be employed as antigen to induce high levels of antibody production, and different coupling methods show different effects on their antigenicity. The results of this work has laid an important basis for the development of polyclonal and monoclonal antibodies against prion replicationprotein.