Muñoz Pilar M, Estevan Maite, Marín Clara M, Jesús De Miguel M, Jesús Grilló M, Barberán Montserrat, Irache Juan M, Blasco Jose M, Gamazo Carlos
CITA, Unidad de Sanidad Animal, Ap 727, 50080 Zaragoza, Spain.
Vaccine. 2006 Mar 10;24(11):1897-905. doi: 10.1016/j.vaccine.2005.10.042. Epub 2005 Nov 4.
Due to the important drawbacks of the Brucella melitensis Rev 1 vaccine, a safer vaccine based on an outer membrane complex from Brucella ovis encapsulated in poly-epsilon-caprolactone (PEC) microparticles (MP) was developed and tested in rams. Homogeneous batches of microparticles were prepared by a new double emulsion solvent evaporation method called "Total Recirculation One-Machine System" (TROMS). Such microparticles presented a mean diameter of 2 microm and displayed an antigen loading of about 13 microg HS per mg of microparticles. Subcutaneous vaccination of rams with 800 microg HS (hot saline antigenic extract of B. ovis) in PEC microparticles induced an adequate serological response against B. ovis antigens and conferred similar protection against challenge with B. ovis to that induced by the living attenuated B. melitensis Rev 1 reference vaccine. By contrast, lower doses (80 microg) of HS-PEC evoked reduced serological responses against B. ovis antigens and did not induce significant protection. The revaccination with 800 microg of HS-PEC increased the intensity and duration of the serological response against B. ovis antigens but did not improve the protection conferred by the single vaccination. Sample sera taken from any of the animals immunized with Rev 1 were seropositive in both Rose Bengal and the Complement Fixation tests (RBT, CFT) used for the diagnosis of smooth Brucella infections. By contrast, no positive reactors in both tests were recorded in the animals vaccinated with HS-PEC, being this a target objective of this study. HS-PEC microparticles can be used as a safe vaccine against brucellosis in rams, but further studies using higher doses of antigens are necessary to exploit their full potential for the prophylaxis of brucellosis in sheep.
由于布鲁氏菌Rev 1疫苗存在重要缺陷，一种基于绵羊布鲁氏菌外膜复合物并包裹于聚-ε-己内酯（PEC）微粒（MP）中的更安全疫苗得以研发，并在公羊身上进行了测试。通过一种名为“全循环单机系统”（TROMS）的新型双乳液溶剂蒸发法制备了均匀批次的微粒。此类微粒的平均直径为2微米，每毫克微粒的抗原负载量约为13微克热盐水抗原提取物（HS）。用800微克HS（绵羊布鲁氏菌热盐水抗原提取物）包裹于PEC微粒中对公羊进行皮下接种，可诱导出针对绵羊布鲁氏菌抗原的适当血清学反应，并赋予与减毒活布鲁氏菌Rev 1参考疫苗诱导的类似保护，以抵抗绵羊布鲁氏菌的攻击。相比之下，较低剂量（80微克）的HS-PEC引起的针对绵羊布鲁氏菌抗原的血清学反应降低，且未诱导出显著保护作用。用800微克HS-PEC进行再次接种可增加针对绵羊布鲁氏菌抗原的血清学反应的强度和持续时间，但并未改善单次接种所赋予的保护作用。从用Rev 1免疫的任何动物采集的样本血清在用于诊断光滑型布鲁氏菌感染的玫瑰红试验和补体结合试验（RBT、CFT）中均呈血清阳性。相比之下，在用HS-PEC接种的动物中，两项试验均未记录到阳性反应动物，这是本研究的一个目标。HS-PEC微粒可作为公羊布鲁氏菌病的安全疫苗，但需要进一步研究使用更高剂量的抗原，以充分发挥其在绵羊布鲁氏菌病预防中的潜力。
