CpG ODN对鸡新城疫LaSota活疫苗的免疫增强效应

Immune Enhancement of CpG ODN on LaSota Lived Vaccine against Newcastle Disease in Chickens

将3种不同的未甲基化CpG ODN分别与新城疫LaSota活疫苗混合后,经滴鼻和点眼免疫鸡,通过检测鸡血清中HI抗体、外周血T淋巴细胞增殖活性、诱导巨噬细胞分泌NO含量,以及刺激外周血淋巴细胞表达IFN-γ、IL-6与IL-1βmRNA量,分析各CpG ODN对新城疫LaSota活疫苗免疫效果的影响。结果表明,经2次免疫后,含GTCGTT核心基序的CpG ODN1组,鸡血清平均HI抗体效价最高达8.2log2、淋巴细胞刺激指数达9.836、NO分泌量达35.833μmol/L,分别比疫苗单独免疫组高出2个滴度(P<0.05)、4.4(P<0.01)、27.6μmol/L(P<0.01);含GACGTT核心基序的CpG ODN2组增强作用不明显,与疫苗单独免疫组无差异;而CpG ODN3的免疫刺激活性由于受其侧翼序列的影响,作用明显减弱甚至丧失。对细胞因子的影响,CpG ODN3组IFN-γmRNA表达量稍高于CpG ODN1组,而其余细胞因子均以CpG ODN1组表达水平最高(P<0.05)。由此证明CpG ODN1能显著增强鸡对新城疫LaSota活疫苗的体液和细胞免疫反应,可以作为高效的免疫增强剂。

The immune effects of three different unmethylated CpG oligodeoxynucleotides （CpG ODN） on LaSota lived vaccine against Newcastle disease in chickens inoculated by intranasal and eye-drop route were investigated and the CpG ODNs were evaluated for their ability to activate B lymphocytes to induce HI antibody, promote T lymphocytes proliferation, induce macrophage nitric oxide （NO） production, and stimulate mRNA expression of IFN y,IL 6 and IL-1β in periph eral blood mononuclear cells （PBMC） in this study. After two successive immunizations, our resuits demonstrated that the birds in CpG ODN1-group produced a mean serum HI antibody titer of 8.2 log2, a lymphoproliferative stimulation index （SI） of 9. 836 and a NO production of 35. 833 μmol/L. There existed an increment by 2 log2 （P〈0. 05）, 4.4（P〈0. 01）, 27.6μmol/L （P〈0.01）, respectively, compared with control group （inoculated with LaSota lived vaccine only）. CpG ODN2 containing the GACGTT motif in group 2 showed a faint efficacy and there was no difference between this group and control group. However, deviation of flanking bases of CpG ODN3 in group 3 significantly reduced or diminished its stimulatory activity. Meanwhile, it was found that there were remarkable mRNA expression of IFN-γ,IL-6 and IL-1β in peripheral blood mononuclear cells of CpG ODN1-treated birds（P〈0.05）, in despite of CpG ODN3 induced a littie higher level of mRNA expression of IFN-γ than that of CpG ODNl-group. These results indieate that CpG ODN1 is a potent LaSota lived vaccine adjuvant for stimulating both antibody and cell mediated immune responses in chickens.