Brucella spp. is the causative agent of brucellosis, one of the worldwide diseases. The pathogen infects humans and animals mainly through the digestive or respiratory tract. Therefore, induction of mucosal immunity is required as the first line of defense. In this study, three Brucella abortus recombinant proteins, malate dehydrogenase (rMdh), outer membrane proteins (rOmp) 10 and 19 were loaded in mucoadhesive chitosan nanoparticles (CNs) and induction of mucosal and systemic immunity were investigated after intranasal immunization of BALB/c mice. These antigens were also coimmunized as cocktail (rCocktail) to evaluate multiple antigen specific vaccine candidates. At 6-weeks post-immunization (wpi), antigen specific total IgG was increased in all of the immunized groups, predominantly IgG1. In addition, spleenocyte from rMdh-, rOmp19-, and rCocktail-immunized groups significantly produced IFN-γ and IL-4 suggesting the induction of a mixed Th1-Th2 response. For mucosal immunity, anti-Mdh IgA from nasal washes and fecal excretions, and anti-Omps IgA from sera, nasal washes, genital secretions and fecal excretions were significantly increased in single antigen immunized groups. In the rCocktail-immunized group, anti-Mdh IgA were significantly increased while anti-Omps IgA was not. Collectively, this study indicates that comprise of B. abortus antigen-loaded CNs elicited the antigen-specific IgA with a Th2-polarized immune responses and combination of the highly immunogenic antigens elicited IgG specific to each type of antigen.

布鲁氏菌属。是布鲁氏菌病的致病因子，布鲁氏菌病是全球性疾病之一。病原体主要通过消化道或呼吸道感染人和动物。因此，需要诱导粘膜免疫作为第一道防线。在这项研究中，三个布鲁氏流产将重组蛋白，苹果酸脱氢酶（rMdh），外膜蛋白（rOmp）10和19装入粘膜粘附性壳聚糖纳米颗粒（CNs）中，并在鼻腔免疫BALB / c小鼠后研究了粘膜和全身免疫的诱导作用。这些抗原也作为鸡尾酒（rCocktail）被共免疫，以评估多种抗原特异性疫苗候选物。免疫后6周（wpi），所有免疫组的抗原特异性总IgG均增加，主要是IgG1。另外，来自rMdh-，rOmp19-和rCocktail免疫组的脾细胞显着产生IFN-γ和IL-4，表明诱导了混合的Th1-Th2反应。对于粘膜免疫，可通过洗鼻液和粪便排泄物获得抗-Mdh IgA，通过血清，鼻洗液获得抗-Omps IgA，在单抗原免疫组中，生殖器官分泌物和粪便排泄物显着增加。在rCocktail免疫组中，抗-Mdh IgA显着增加，而抗-Omps IgA没有。总体而言，这项研究表明，负载有流产双歧杆菌的CNs引发具有Th2极化的免疫反应的抗原特异性IgA，并且高度免疫原性抗原的组合引发了对每种抗原特异的IgG。