Molecular mechanism of vaccination effect induced by stress protein-Malaria CS antigen

已经显示，用在体内结合天然存在的肽或通过体外重建结合合成肽的gp96和hsc70免疫可诱导肽特异性CTL。此外，分枝杆菌热休克蛋白70共价融合到OVA衍生的片段显示产生MHC I类限制性CL反应。本研究将约氏疟原虫环子孢子蛋白、肿瘤抗原、HY抗原和卵清蛋白等5种不同的CTL表位分别与小鼠热休克相关蛋白70（hsc70）的N端或C端融合，并在大肠杆菌中表达。通过用所有融合蛋白接种诱导肽特异性CTL，表明CTL表位的同源侧翼区是不必要的。根注射是CIL诱导的关键。CD8 ^+ T细胞的启动不需要CD4^+ T细胞，用融合蛋白脉冲的骨髓来源的树突状细胞接种也能引起CL反应。此外，通过使用hsc70的缺失突变体，将hsc70产生CTL的最负责区域定位到hsc70_<280-385>。

Immunization with gp96 and hsc70 that bound naturally occurring peptides in vivo or bound synthetic peptides by in vitro reconstitution, have been shown to induce peptide specific CTLs. In addition, mycobacterial hsp70 covalently fused to OVA-derived fragments was shown to generate MHC class I restricted CL responses. In the present study, five different CTL epitopes, including peptides derived from Plasmodium yoelii circumsporozoite protein, tumor antigens, HY antigen and OVA, were genetically fused either to N or C terminus of murine heat shock cognate protein 70 (hsc70), and expressed in E.coli. Peptide specific CTLs were induced by vaccination with all the fusion proteins, indicating that no cognate flanking regions of CTL epitopes are necessary. A root of injection was crucial for CIL induction. CD4^+ T cells were not required for the priming of CD8^+ T cells, and vaccination with bone-marrow derived dendritic cells pulsed with fusion proteins also elicited CL responses. Furthermore, by using deletion mutants of hsc70, the most responsible region of hsc70 to generate CTLs was mapped to hsc70_<280-385>.