Arenas-Gamboa Angela M, Ficht Thomas A, Kahl-McDonagh Melissa M, Rice-Ficht Allison C
Veterinary Pathobiology, Texas A&M University and Texas Agricultural Experiment Station, College Station, TX 77845-1114, USA.
Infect Immun. 2008 Jun;76(6):2448-55. doi: 10.1128/IAI.00767-07. Epub 2008 Mar 24.
The development of safe and efficacious immunization systems to prevent brucellosis is needed to overcome the disadvantages of the currently licensed vaccine strains that restrict their use in humans. Alginate microspheres coated with a protein of the parasite Fasciola hepatica (vitelline protein B [VpB]) and containing live Brucella melitensis attenuated mutant vjbR::Tn5 (BMEII1116) were evaluated for vaccine efficacy and immunogenicity in mice. A single immunization dose in BALB/c mice with the encapsulated vjbR mutant improved protection against wild-type B. melitensis 16M challenge compared to the nonencapsulated vaccine strain (P < 0.05). The encapsulated mutant was also shown to induce a sustained elevation of Immunoglobulin G levels. Cytokine secretion from spleen cells of mice vaccinated with the encapsulated vjbR::Tn5 revealed elevated secretion of gamma interferon and interleukin-12, but no interleukin-4, suggesting an induction of a T helper 1 response reflecting the enhanced immunity associated with microencapsulation. Together, these results suggest that microencapsulation of live attenuated organisms offers the ability to increase the efficacy of vaccine candidates.
为克服目前已获许可的疫苗株在人体使用方面的局限性，需要开发安全有效的免疫接种系统来预防布鲁氏菌病。对包被有肝片吸虫（Fasciola hepatica）一种蛋白质（卵黄蛋白B [VpB]）且含有减毒活布鲁氏菌（Brucella melitensis）突变体vjbR::Tn5（BMEII1116）的藻酸盐微球进行了小鼠疫苗效力和免疫原性评估。与未包被的疫苗株相比，在BALB/c小鼠中单次接种包被的vjbR突变体可增强对野生型布鲁氏菌16M攻击的保护作用（P < 0.05）。包被的突变体还可诱导免疫球蛋白G水平持续升高。接种包被的vjbR::Tn5的小鼠脾细胞分泌的细胞因子显示，γ干扰素和白细胞介素-12分泌增加，但白细胞介素-4未增加，这表明诱导了辅助性T细胞1型反应，反映了与微囊化相关的增强免疫力。总之，这些结果表明，减毒活生物体的微囊化能够提高候选疫苗的效力。
