关键词: CpG ODN, 新城疫LaSota活疫苗, 免疫刺激活性, 鸡

Abstract: 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-γ,IL-6 and IL-1β in peripheral blood mononuclear cells (PBMC) in this study. After two successive immunizations, our results demonstrated that the birds in CpG ODN1-group produced a mean serum HI antibody titer of 8.2log2, a lymphoproliferative stimulation index (SI) of 9.836 and a NO production of 35.833 μmol/L. There existed an increment by 2log2 (P<0.05), 4.4(P<0.01), 27.6 μmol/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 little higher level of mRNA expression of IFN-γ than that of CpG ODN1-group. These results indicate that CpG ODN1 is a potent LaSota lived vaccine adjuvant for stimulating both antibody and cell mediated immune responses in chickens.

Key words: CpG ODN, LaSota lived vaccine against Newcastle disease, immunostimulatory activity, chicken