Wyckoff John H, Howland Jeri L, Scott Catherine M O'Connell, Smith Robert A, Confer Anthony W
Department of Veterinary Pathobiology, 250 McElroy Hall, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078-2007, USA.
Vet Microbiol. 2005 Nov 30;111(1-2):77-87. doi: 10.1016/j.vetmic.2005.09.004. Epub 2005 Oct 19.
Augmentation of immunization of cattle Brucella abortus S19 or a B. abortus soluble protein extract (SPEBA) vaccine through administration of recombinant bovine IL 2 (rBoIL 2) was evaluated. Seventy-five heifers were divided among 6 groups that were treated with the following: Group 1, no treatment; Group 2, rBoIL 2 (1microg/kg) on day 0; Group 3, SPEBA (2 mg) on day 0 and week 9; Group 4, SPEBA + rBoIL 2 on day 0, SPEBA on week 9; Group 5, S19 (10(7) CFU) on day 0 and week 9; Group 6, S19 + rBoIL 2 on day 0, S19 only on week 9. Approximately, 6 months after vaccination, cattle were bred by natural service, and at mid-gestation pregnant cattle were challenged intraconjunctivally with 9.1 x 10(5) CFU of virulent B. abortus S2308. Pre- and post-challenge antibody responses were measured by an enzyme-linked immunosorbent assay, a particle concentration fluorescence assay, and the card test. Lymphoproliferation (LP) responses to gamma-irradiated B. abortus and SPEBA antigens were measured in peripheral blood mononuclear cells. After vaccination, antibody responses to B. abortus elevated rapidly in SPEBA- and S19-vaccinates with and without rBoIL 2, however, these responses were significantly (P < 0.05) higher in vaccinates which also received rBoIL 2. Antibody levels for all vaccinated groups had returned to those of negative control groups by the challenge date with the exception of the SPEBA/rBoIL 2 group. In general, LP responses were higher in vaccinated or rBoIL 2-treated cattle than for unvaccinated controls. Challenge of 48 pregnant heifers resulted in abortions in 4/9 of Group 1, 0/9 of Group 2, 4/8 of Group 3, 2/9 of Group 4, 1/7 of Group 5, and 0/6 of Group 6 cattle. Treatment with rBoIL 2 alone (Group 2) provided significant (P < 0.05) protection from infection, abortions and induction of sero-positive status compared to untreated (Group 1) cattle. Co-administration of rBoIL 2 with S19 resulted in significant (P < 0.05) augmentation in onset, duration and magnitude of LP responses to B. abortus antigens following challenge. Characterization of the cytokine response of bovine monocyte-derived macrophages by real-time polymerase chain reaction indicated that in vitro stimulation of these cells with rBoIL 2 resulted in a profound up-regulation of genes encoding tumor necrosis factor-alpha, IL 12p40, and interferon-gamma reflecting activation of the cells. Overall, rBoIL 2-treatment was associated with fewer infections, sero-conversions and a significant (P = 0.02) level of protection against abortion as compared to vaccination alone or no treatment.
通过给予重组牛白细胞介素2（rBoIL-2）来增强牛布鲁氏菌S19或流产布鲁氏菌可溶性蛋白提取物（SPEBA）疫苗的免疫效果进行了评估。75头小母牛被分为6组，分别接受以下处理：第1组，不处理；第2组，在第0天给予rBoIL-2（1微克/千克）；第3组，在第0天和第9周给予SPEBA（2毫克）；第4组，在第0天给予SPEBA + rBoIL-2，在第9周给予SPEBA；第5组，在第0天和第9周给予S19（10⁷CFU）；第6组，在第0天给予S19 + rBoIL-2，在第9周仅给予S19。大约在接种疫苗6个月后，通过自然交配使母牛受孕，在妊娠中期，对怀孕母牛进行结膜内接种9.1×10⁵CFU的强毒流产布鲁氏菌S2308。通过酶联免疫吸附测定、颗粒浓度荧光测定和平板凝集试验测量攻毒前后的抗体反应。在外周血单核细胞中测量对γ射线照射的流产布鲁氏菌和SPEBA抗原的淋巴细胞增殖（LP）反应。接种疫苗后，无论有无rBoIL-2，接受SPEBA和S19疫苗接种的牛对流产布鲁氏菌的抗体反应迅速升高，然而，在同时接受rBoIL-2的接种牛中，这些反应显著（P < 0.05）更高。到攻毒日期时，除了SPEBA/rBoIL-2组外，所有接种组的抗体水平已恢复到阴性对照组的水平。一般来说，接种疫苗或接受rBoIL-2处理的牛的LP反应高于未接种疫苗的对照组。对48头怀孕小母牛进行攻毒，结果第1组9头中有4头流产，第2组9头中0头流产，第3组8头中有4头流产，第4组9头中有2头流产，第5组7头中有1头流产，第6组6头中0头流产。与未处理（第1组）的牛相比，单独用rBoIL-2处理（第2组）可提供显著（P < 0.05）的抗感染、抗流产保护，并可防止血清学阳性状态的诱导。rBoIL-2与S19联合给药导致攻毒后对流产布鲁氏菌抗原的LP反应的起始、持续时间和幅度显著（P < 0.05）增强。通过实时聚合酶链反应对牛单核细胞衍生巨噬细胞的细胞因子反应进行表征表明，用rBoIL-2体外刺激这些细胞会导致编码肿瘤坏死因子-α、IL-12p40和干扰素-γ的基因显著上调，反映了细胞的激活。总体而言，与单独接种疫苗或不处理相比，rBoIL-2处理与更少的感染、血清转化以及显著（P = 0.02）的抗流产保护水平相关。
