布鲁氏菌病弱毒活疫苗经不同黏膜途径免疫奶牛的排菌程度及免疫反应

Immune Effect and Bacterial Excretion of Dairy Cattle vaccinated with Live Attenuated Brucellosis Vaccine via Different Mucosal Immunization Approaches

关键词:  布鲁氏菌病疫苗  黏膜免疫  排菌  抗体  细胞因子

Key words:  Brucellosis vaccine  mucosal immunization  brucella excretion  antibody titer  cytokines secreting

摘要:

为探究布鲁氏菌病疫苗经不同黏膜途径免疫奶牛后对体液免疫与细胞免疫水平及疫苗体外排菌方面的影响,本试验将80头10-12月龄的奶牛平均分为四组,通过眼部滴注(A组)、口腔喷注(B组)、阴道灌注(C组)三种黏膜免疫途径对奶牛接种布鲁氏菌病弱毒活疫苗(A19株),并与皮下注射免疫组(D组)进行比较。测定了免疫后7d内黏膜免疫组的排菌情况,180d内四组免疫奶牛的抗体效价和60d内四组免疫奶牛的外周血淋巴细胞细胞因子分泌(IFN-γ、IL-2和IL-4)水平。结果显示：黏膜免疫组在免疫后5d内均有不同程度的排菌,以免疫后1d内排菌量为最高,并且在黏膜免疫组中阴道灌注组排菌量最低；各组奶牛在免疫后20d时MSAT测定抗体效价平均值均上升至最高,之后持续下降,黏膜免疫组的抗体水平显著低于注射免疫组,且在黏膜免疫组中阴道灌注组的抗体水平最高；A组和B组奶牛在免疫后120d RBT检测无阳性,C组在免疫后150d RBT检测无阳性,D组在免疫后180d RBT检测阳性率40%；B组、C组在免疫后7d,A组、D组在免疫后20d IFN-γ分泌量达到最高值,各组IL-2和IL-4分泌量未见明显变化,黏膜免疫组中阴道免疫组的IFN-γ分泌量为最高,仅次于注射免疫。结果表明,阴道灌注是一种较优的奶牛布鲁氏菌病黏膜免疫方式。

Abstract:

To investigate the effects of different mucosal immunization approaches on humoral immunity response、cellular immunity response and brucella excretion situation of Dairy Cattle vaccinated with live brucellosis vaccine. 80 cows (10-12 months old) were divided into four groups (20 for each group) .The cows were inoculated with Brucella A19(B.abortus)by eye infusion (group A), oral injection (group B) ,vaginal perfusion (group C) and subcutaneous injection(group D) respectively with same full standard dose. We checked the brucella excretion situation within 7 days after immunization for group A, B and C, followed the antibody changes within 180 days and cytokines secretion (IFN-γ,IL-2,IL-4) within 60 days for group A , B , C and D. the results showed that brucella excretions of three mucosal immunization approaches were lasted for 5 days and reached highest within the first day; the brucella excretion of group C was the lowest compared to group A and B; the antibody titer and the duration of antibody positive rates of group A , B , C were significantly lower than group D, for all the cows the antibody titer reached the peak on 20dpi, furthermore group C had the highest antibody level compared to other two mucosal immunization groups; the antibody positive rates of group A , B ,C were all 0% on 120dpi, 120dpi,150dpi respectively while the antibody positive rate of group D was 40% on 180dpi; tested groups’ IFN-γ excretions reached the peak on 7dpi (group B and group C)or 20dpi (group A and group D) while the IL-2 and IL-4 secretion had no significantly change, IFN-γ excretion of group C was the most among all the mucosal immunization groups and a little lower than group D. Our results indicate that vaginal perfusion is a much better approach for vaccination of dairy cattle with live attenuated brucellosis vaccine.