Norwegian College of Fishery Science, University of Tromsø, Breivika, Tromsø N-9037, Norway.
Vaccine. 2011 Oct 26;29(46):8338-49. doi: 10.1016/j.vaccine.2011.08.087. Epub 2011 Aug 31.
Polymeric nanoparticles (NPs) of poly (lactic-co-glycolic) acid (PLGA) possess adjuvant properties. To date, there are few studies exploring their application as antigen carriers for vaccination of fish. This study presents a preclinical assessment of the early innate and adaptive immune responses in Atlantic salmon following immunization with PLGA NPs. A model antigen (TNP-LPH) and an immunostimulant (β-glucan) were entrapped in NPs of 300-400nm either alone or in combination. Both the antigen and the β-glucan were efficiently entrapped (>50%) in particles and an antigen release study indicated particle stability up to 50 days at 8°C. Spleen and head kidney were analyzed for pro-inflammatory markers (TNF-α, IL-1β, IL-8, C3a) and T cell cytokines, effector molecules and transcription factors (IFN-γ, T-bet, GATA-3, granzyme A, IL-10, Foxp3) at mRNA transcription levels 2, 4 and 8 days post i.p. immunization. NPs alone were able to moderately up-regulate pro-inflammatory immune responses. Addition of immunogenic cargo, either an antigen or β-glucan generally increased the gene expression of pro-inflammatory markers, while administering both resulted in the highest gene expression. These findings were also reflected by concurrently increased levels of IL-10. Comparing the treatment groups injected with antigen and β-glucan co-administered either in NPs or FCA demonstrated that the magnitude of the acute pro-inflammatory responses was equal between the treatments or highest in the NP injected group. Although elevated expression of granzyme A in the NP injected groups (carrying antigen and/or β-glucan) was observed, PLGA NPs were unable to induce T cell differentiation on mRNA gene expression levels, as increased levels of the indicating cytokines and transcriptions factors failed to occur. In conclusion, this study demonstrates that PLGA NPs have potential as an adjuvant in salmon vaccines as they enhance the early pro-inflammatory responses to immunization.
聚乳酸-羟基乙酸共聚物（PLGA）的聚合物纳米颗粒（NPs）具有佐剂特性。迄今为止，很少有研究探索其作为鱼类疫苗抗原载体的应用。本研究通过对大西洋鲑鱼进行免疫接种，对其早期固有和适应性免疫反应进行了临床前评估。将模型抗原（TNP-LPH）和免疫佐剂（β-葡聚糖）分别单独或联合包封在 300-400nm 的 NPs 中。抗原和β-葡聚糖均能有效地包封（>50%）在颗粒中，释放研究表明在 8°C 下 50 天内颗粒稳定。脾脏和头肾在注射后 2、4 和 8 天通过 mRNA 转录水平分析促炎标志物（TNF-α、IL-1β、IL-8、C3a）和 T 细胞细胞因子、效应分子和转录因子（IFN-γ、T-bet、GATA-3、颗粒酶 A、IL-10、Foxp3）。单独的 NPs 能够适度上调促炎免疫反应。添加免疫原性货物，无论是抗原还是β-葡聚糖，通常都会增加促炎标志物的基因表达，而同时添加两者则会导致基因表达最高。同时增加的 IL-10 水平也反映了这些发现。将与 FCA 一起注射的抗原和β-葡聚糖共同给药的治疗组与注射抗原和β-葡聚糖的 NPs 治疗组进行比较，结果表明两种处理方式的急性促炎反应程度相同，或在 NPs 注射组中最高。尽管在注射 NPs（携带抗原和/或β-葡聚糖）的各组中观察到颗粒酶 A 的表达升高，但 PLGA NPs 无法在 mRNA 基因表达水平上诱导 T 细胞分化，因为指示细胞因子和转录因子的水平升高并未发生。总之，本研究表明，PLGA NPs 作为鱼类疫苗佐剂具有潜力，因为它们增强了对免疫接种的早期促炎反应。
