Linghua Zhang, Xingshan Tian, Fengzhen Zhou
Microbiological Staff Room, College of Life Sciences, South China Agricultural University, Wushan Road, Tianhe district, Guangzhou 510642, GuangDong, China.
Vaccine. 2008 Jan 10;26(2):224-33. doi: 10.1016/j.vaccine.2007.10.058. Epub 2007 Nov 20.
Numerous studies have demonstrated that oligonucleotides containing CpG motifs (CpG ODN) are efficient immunoadjuvants to various antigens administered by parenteral routes to mice. Recently, it has been found that CpG ODNs also is a promising mucosal adjuvant in mice. To date, there have been no studies to screen the optimal CpG sequence and modified ODN backbone to piglets in vivo, when delivered by oral route. We have previously demonstrated that human-specific CpG ODN is a potent adjuvant to pseudorabies live attenuated virus (PRV) vaccine when administered subcutaneously (SC) or ocularly in piglets. In this study, we screened and evaluated the optimal CpG sequences (porcine-specific, human-specific, mouse-specific ODN) and optimal backbone (SOS-backbone consisting of a nuclease-resistant phosphorothioate guanosines at the 5' and the 3'-end and with a phosphodiester (O) in the center and phosphorothioate (S) backbone (S-backbone)) to PRV vaccine delivered orally in piglets. The proliferation of peripheral blood mononuclear cells (PBMCs), IFN-gamma and IL-4 in serum, and the titre of IgG, IgG2/IgG1 isotype in serum and IgA in intestinal washings and feces to PRV vaccine were tested at different time-points. The results suggested that, CpG ODNs augmented systemic (IgG in serum, T-cell proliferation) and mucosal (IgA in intestinal washings and feces) immune responses against antigen. CpG ODNs stimulated both T-helper type1 (Th1) (IgG2) and Th2 (IgA) responses when delivered orally. With the same backbone, the porcine-specific ODN-induced responses were comparable with human-specific ODNs, but stronger than mouse-specific CpG ODNs. SOS-backbone induced a stronger IFN-gamma and proliferative responses than S-backbone, while antibody responses induced by SOS-backbones were slightly less or similar with S-backbone. The in vivo data demonstrate for the first time that porcine-specific and human-specific ODNs both are optimal sequences for mucosal system in piglets.
众多研究表明，含有CpG基序的寡核苷酸（CpG ODN）是通过非肠道途径给小鼠注射各种抗原时的有效免疫佐剂。最近，人们发现CpG ODN在小鼠中也是一种有前景的黏膜佐剂。迄今为止，尚未有研究在仔猪经口服途径给药时，筛选最佳的CpG序列和修饰的ODN骨架。我们之前已经证明，人特异性CpG ODN在仔猪皮下（SC）或经眼给药时，是伪狂犬病减毒活疫苗（PRV）的有效佐剂。在本研究中，我们筛选并评估了最佳的CpG序列（猪特异性、人特异性、小鼠特异性ODN）和最佳骨架（SOS骨架，在5'和3'-末端由抗核酸酶的硫代磷酸鸟苷组成，中间为磷酸二酯（O），硫代磷酸（S）骨架（S-骨架））用于经口服给仔猪的PRV疫苗。在不同时间点检测外周血单核细胞（PBMC）的增殖、血清中的IFN-γ和IL-4，以及血清中IgG、IgG2/IgG1亚型的滴度和肠道冲洗液及粪便中针对PRV疫苗的IgA。结果表明，CpG ODN增强了针对抗原的全身（血清中的IgG、T细胞增殖）和黏膜（肠道冲洗液和粪便中的IgA）免疫反应。口服给药时，CpG ODN刺激了辅助性T细胞1型（Th1）（IgG2）和Th2（IgA）反应。在相同骨架下，猪特异性ODN诱导的反应与人特异性ODN相当，但强于小鼠特异性CpG ODN。SOS骨架诱导的IFN-γ和增殖反应比S-骨架更强，而SOS骨架诱导的抗体反应略低于或与S-骨架相似。体内数据首次证明，猪特异性和人特异性ODN都是仔猪黏膜系统的最佳序列。
