Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK; Centre for Environment, Fisheries and Aquaculture Science, Barrack Road, the Nothe, Weymouth, Dorset, DT4 8UB, UK.
Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, UK.
Fish Shellfish Immunol. 2022 Feb;121:505-515. doi: 10.1016/j.fsi.2021.09.044. Epub 2021 Oct 19.
The development of effective vaccines is a critical step towards the domestication of emerging fish species for aquaculture. However, traditional vaccine delivery through intraperitoneal (i.p.) injection requires fish to reach a minimum size and age and therefore cannot provide protection at early developmental stages when infection may occur. This study investigated the effectiveness of immersion vaccination with respect to immunocompetence in a cleaner fish species (ballan wrasse, Labrus bergylta, Ascanius) used in Atlantic salmon farming as an alternative means to control sea lice. The species is susceptible to atypical strains of Aeromonas salmonicida (aAs) at early life stages (<15 g), when i.p. vaccination is not applicable. While immersion vaccination is currently used in commercial hatcheries, the optimal fish size for vaccination, and efficacy of the vaccine delivered by this route has not yet been established. Importantly, efficacy depends on the capability of the species immune system to recognise antigens and process antigens to trigger and produce an adaptive immune response, (process known as immunocompetence). In this study, the efficacy of a polyvalent autogenous vaccine administered by immersion in juvenile ballan wrasse and the subsequent immune response induced was investigated after prime and booster vaccination regimes. In addition, temporal expression (0-150 days post hatch) of adaptive immune genes including major histocompatibility complex (MHC II CD74 molecule) and immunoglobulin M (IgM) was assessed using quantitative PCR (qPCR). Prime and/or boost vaccination by immersion of juvenile ballan wrasse (0.5 g and 1.5 g corresponding to 80 and 170 days post hatch (dph), respectively) did not provide significant protection against aAs vapA V after bath challenge under experimental conditions. Despite no evident protection >80 dph, MHC II and IgM transcripts were first reported at 35 and 75 dph, respectively, suggesting a window of immunocompetence. The results provide important new information on the onset of adaptive immunity in ballan wrasse and highlight that immersion vaccination in the species for protection against aAs should be performed at later developmental stages (>1.5 g) in the hatchery.
开发有效的疫苗是实现新兴鱼类养殖驯化的关键步骤。然而，通过腹腔内（i.p.）注射进行传统疫苗接种需要鱼类达到最小尺寸和年龄，因此不能在感染可能发生的早期发育阶段提供保护。本研究调查了在大西洋鲑鱼养殖中用作控制海虱的替代方法的清洁鱼（白斑狗鱼，Labrus bergylta，Ascanius）的浸浴免疫接种对免疫能力的有效性。当腹腔内接种不适用于早期生命阶段（<15 克）时，该物种易受非典型气单胞菌（aAs）菌株的影响。虽然浸浴免疫接种目前在商业孵化场中使用，但尚未确定最佳的鱼类接种大小和通过这种途径接种疫苗的功效。重要的是，功效取决于该物种免疫系统识别抗原和处理抗原以触发和产生适应性免疫反应的能力（称为免疫能力）。在这项研究中，研究了在幼鱼白斑狗鱼中通过浸浴给予多价自体疫苗的功效以及在初级和加强免疫接种方案后诱导的随后免疫反应。此外，使用定量 PCR（qPCR）评估了适应性免疫基因（包括主要组织相容性复合体（MHC II CD74 分子）和免疫球蛋白 M（IgM））的时间表达（孵化后 0-150 天）。通过浸浴对幼鱼白斑狗鱼进行初级和/或加强免疫接种（0.5 克和 1.5 克分别对应孵化后 80 和 170 天（dph）），在实验条件下用 bath 挑战后不能提供针对 aAs vapA V 的显著保护。尽管在>80 dph 时没有明显的保护，但 MHC II 和 IgM 转录物分别在 35 和 75 dph 首次报道，表明存在免疫能力窗口。这些结果提供了有关白斑狗鱼适应性免疫的起始的重要新信息，并强调在孵化场中应在发育后期（>1.5 克）对该物种进行浸浴免疫接种以提供针对 aAs 的保护。
