猪带绦虫重组Bb-TSO45W-4B-TSOL18疫苗诱导仔猪免疫应答的动态观察

目的 研究猪带绦虫重组Bb-TSO45W-4B-TSOL18疫苗免疫仔猪后诱导免疫应答的动态变化。方法 将16头40 d龄健康仔猪均分为4组:重组Bb-TSO45W-4B-TSOL18疫苗组、重组Bb-TSO45W-4B疫苗组、重组Bb-TSOL18疫苗组和双歧杆菌液体培养基(MRS)对照组。各疫苗组均以1011CFU灌胃免疫,间隔2周免疫1次,共免疫2次。在免疫后0、2、4、6、8周采集仔猪前腔静脉血,分离血清和外周血淋巴细胞(PBMC)。采用ELISA法检测仔猪血清IgG、IgG1及IgG2a水平和PBMC培养上清液IL-2、IFN-γ、IL-4及IL-10水平;MTT比色法检测PBMC增殖水平;FCM检测CD₄⁺和CD₈⁺T细胞亚群。结果 　各疫苗组血清IgG、IgG1、IgG2a水平均在免疫后2~8周升高,均在免疫后4周、6周、4周达较高水平;PBMC增殖水平均在免疫后2~8周升高,均在免疫后6周达较高水平CD₄⁺和CD₈⁺T细胞水平均在免疫后2~8周升高,均在免疫后8周和6周达较高水平;PBMC培养上清液IL-2、IFN-γ、IL-4、IL-10水平分别在免疫后2~6周、2~8周、4~6周和2~8周升高,分别在免疫后4周、6周、4周和8周达较高水平。各疫苗组上述指标与MRS对照组比较差异均有统计学意义(P<0.05);重组Bb-TSO45W-4B-TSOL18疫苗组与重组Bb-TSO45W-4B疫苗组和重组Bb-TSOL18疫苗组比较差异均有统计学意义(P<0.05)。结论 猪带绦虫重组Bb-TSO45W-4B-TSOL18疫苗免疫仔猪可诱导产生特异性的免疫应答,且TSO45W-4B-TSOL18融合抗原疫苗组优于TSO45W-4B或TSOL18单一抗原疫苗组。

Dynamic observation of immune responses induced in piglets by immunization with recombinant bifidobacterium(Bb)-TSO45W-4B-TSOL18 vaccine of Taenia solium

To study dynamical changes of immune responses induced in piglets by immunization with recombinant bifidobacterium (Bb)-TSO45W-4B-TSOL18 vaccine of Taenia solium, sixteen healthy piglets of 40 days old were randomly divided into four groups: rBb-TSO45W-4B-TSOL18 vaccine group, rBb-TSO45W-4B vaccine group, rBb-TSOL18 vaccine group, and Bb liquid medium (MRS) control group. All vaccine groups were given 10¹¹ CFU through intragastric immunization. A total of two times of immunization were conducted, once for every two weeks. On 0th, 2nd, 4th, 6th and 8th week after immunization, the blood from precaval vein were collected to separate serum and peripheral blood lymphocytes (PBMC). Levels of IgG, IgG1 and IgG2a was detected by enzyme linked immunosorbent assay(ELISA). Proliferation level of PBMC was detected by methyl thiazolyl tetrazolium (MTT) method. Levels of IL-2, IFN-γ, IL-4 and IL-10 in PBMC culture supernatant were determined by ELISA. Percentage of CD₄⁺ and CD₈⁺T cell subsets were detected by flow cytometry (FCM). The study demonstrated that levels of IgG, IgG1 and IgG2a in all vaccine groups increased from 2 to 8 weeks after immunization, and reached the highest level by the 4th week, 6th week, and 4th week. Proliferation level of PBMC increased from 2 to 8 weeks, and reached the highest level by the 6th week. Percentage of CD₄⁺ and CD₈⁺T cells increased from 2 to 8 weeks, and reached the highest level by the 8th week and 6th week. Levels of IL-2, IFN-γ, IL-4 and IL-10 in PBMC culture supernatant increased from 2 to 6 weeks, 2 to 8 weeks, 4 to 6 weeks and 2 to 8 weeks, and reached the highest level by the 4th week, 6th week, 4th week and 8th week. The differences of above indexes between all vaccine groups and MRS control group were statistically significant. The differences between rBb-TSO45W-4B-TSOL18 vaccine group and rBb-TSO45W-4B vaccine group or rBb-TSOL18 vaccine group were statistically significant. It was concluded that rBb-TSO45W-4B-TSOL18 vaccine of Taenia solium might induce piglets to produce specific immune responses, and the immune effect of TSO45W-4B-TSOL18 fusion antigen vaccine is better than that of TSO45W-4B or TSOL18 single antigen vaccine.