Tandberg Julia, Lagos Leidy, Ropstad Erik, Smistad Gro, Hiorth Marianne, Winther-Larsen Hanne C
1 Department of Pharmaceutical Biosciences, Faculty of Mathematics and Natural Science, School of Pharmacy, University of Oslo , Oslo, Norway .
2 Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences , Ås, Norway .
Zebrafish. 2018 Aug;15(4):372-381. doi: 10.1089/zeb.2017.1556. Epub 2018 Jun 29.
The introduction of fish vaccination has had a tremendous impact on the aquaculture industry by providing an important measurement in regard to disease control. Infectious diseases caused by intracellular pathogens do, however, remain an unsolved problem for the industry. This is in many cases directly connected to the inability of vaccines to evoke a cellular immunity needed for long-term protection. Thus, there is a need for new and improved vaccines and adjuvants able to induce a strong humoral and cellular immune response. We have previously shown that membrane vesicles (MVs) from the intracellular fish pathogen Piscirickettsia salmonis are able to induce a protective response in adult zebrafish, but the incorporation of an adjuvant has not been evaluated. In this study, we report the use of chitosan as an adjuvant in combination with the P. salmonis-derived MVs for improved immunization against P. salmonis. Both free chitosan and chitosan-coated MVs (cMVs) were injected into adult zebrafish and their efficacy evaluated. The cMVs provided a significant protection (p < 0.05), while a small but nonsignificant reduction in mortalities was registered for fish injected with free chitosan. Both free chitosan and the cMVs were shown to induce an increased immune gene expression of CD 4, CD 8, MHC I, Mpeg1.1, TNFα, IL-1β, IL-10, and IL-6, but to a higher degree in the cMV group. Taken together, the results indicate a potential use of chitosan-coated MVs for vaccination, and that zebrafish is a promising model for aquaculture-relevant studies.
鱼类疫苗接种的引入通过提供疾病控制方面的重要措施，对水产养殖业产生了巨大影响。然而，由细胞内病原体引起的传染病仍然是该行业尚未解决的问题。在许多情况下，这直接与疫苗无法引发长期保护所需的细胞免疫有关。因此，需要新的和改进的疫苗及佐剂，以诱导强烈的体液免疫和细胞免疫反应。我们之前已经表明，来自细胞内鱼类病原体鲑鱼立克次氏体的膜泡（MVs）能够在成年斑马鱼中诱导保护性反应，但尚未评估佐剂的掺入情况。在本研究中，我们报告了壳聚糖作为佐剂与鲑鱼立克次氏体来源的MVs联合使用，以改善针对鲑鱼立克次氏体的免疫接种。将游离壳聚糖和壳聚糖包被的MVs（cMVs）注射到成年斑马鱼中，并评估其功效。cMVs提供了显著的保护作用（p < 0.05），而注射游离壳聚糖的鱼的死亡率有小幅但不显著的降低。游离壳聚糖和cMVs均显示能诱导CD 4、CD 8、MHC I、Mpeg1.1、TNFα、IL-1β、IL-10和IL-6的免疫基因表达增加，但在cMV组中程度更高。综上所述，结果表明壳聚糖包被的MVs在疫苗接种方面具有潜在用途，并且斑马鱼是水产养殖相关研究的一个有前景的模型。
