非甲基化的CpG基元（5’侧翼为两个嘌吟,3’侧翼为两个嘧啶）能够诱发免疫应答,诱生IgM、γ干扰素（IFN-γ）、白细胞介素6(IL-6）、IL-12、IL-18、σ肿瘤坏死因子（TNF-α）。据此,作者设计了两段含该基元的寡核苷酸GCTAGACGTTAGCGT和TCAACGTT。作者构建了编码疟疾环子孢子蛋白（CSP）的DNA疫苗1012/PyCSP,去除1012/PyCSP的多接头,并用人组织纤溶酶原激活物基因的5’非翻译区和前导序列替代之,获得1020/PyCSP。在1020/PyCSP的增强子上游引入两拷贝的 Unmethylated CpG motifs (two purines on the 5 ’flanks and two pyrimidines on the 3’ flanks) are capable of inducing an immune response, inducing IgM, interferon gamma (IFN-γ), interleukin 6 (IL) -6), IL-12, IL-18, sigma tumor necrosis factor (TNF-a). Accordingly, the authors designed two oligonucleotides GCTAGACGTTAGCGT and TCAACGTT containing the motif. The authors constructed DNA vaccine 1012 / PyCSP encoding malaria circumsporozoite protein (CSP), removed the polylinker of 1012 / PyCSP and replaced it with the 5 ’untranslated region and leader sequence of the human tissue plasminogen activator gene to obtain 1020 / PyCSP. Two copies were introduced upstream of the 1020 / PyCSP enhancer