Abstract：
Immersion vaccination, albeit easier to administer than immunization by injection, sometimes has challenges with antigen uptake, resulting in sub-optimal protection. In this research, a new strategy to enhance antigen uptake of a heat-inactivated Vibrio harveyi vaccine in Asian seabass (Lates calcarifer) using oxygen nanobubble-enriched water (ONB) and positively charged chitosan (CS) was explored. Antigen uptake in fish gills was assessed, as was the antibody response and vaccine efficacy of four different combinations of vaccine with ONB and CS, and two control groups. Pre-mixing of ONB and CS before introducing the vaccine, referred to as (ONB + CS) + Vac, resulted in superior antigen uptake and anti-V. harveyi antibody (IgM) production in both serum and mucus compared to other formulas. The integration of an oral booster (4.22 × 108 CFU/g, at day 21-25) within a vaccine trial experiment set out to further evaluate how survival rates post exposure to V. harveyi might be improved. Antibody responses were measured over 42 days, and vaccine efficacy was assessed through an experimental challenge with V. harveyi. The expression of immune-related genes IL1β, TNFα, CD4, CD8, IgT and antibody levels were assessed at 1, 3, and 7-day(s) post challenge (dpc). The results revealed that antibody levels in the group (ONB + CS) + Vac were consistently higher than the other groups post immersion immunization and oral booster, along with elevated expression of immune-related genes after challenge with V. harveyi. Ultimately, this group demonstrated a significantly higher relative percent survival (RPS) of 63 % ± 10.5 %, showcasing the potential of the ONB-CS-Vac complex as a promising immersion vaccination strategy for enhancing antigen uptake, stimulating immunological responses, and improving survival of Asian seabass against vibriosis.
摘要：
沉浸式疫苗接种，尽管比注射免疫更容易管理，有时对抗原摄取有挑战，导致次优保护。在这项研究中,探索了使用富含氧气的纳米气泡的水（ONB）和带正电的壳聚糖（CS）增强亚洲鲈鱼（Latescalcarifer）中热灭活的哈维氏弧菌疫苗抗原摄取的新策略。评估了鱼g中的抗原吸收，与ONB和CS的四种不同疫苗组合的抗体反应和疫苗功效一样，和两个对照组。在引入疫苗之前预先混合ONB和CS，称为(ONB+CS)+VAC，导致优异的抗原摄取和抗V。与其他配方相比，血清和粘液中的harveyi抗体（IgM）产生。口服助推器的积分(4.22×108CFU/g，在第21-25天）的疫苗试验实验中，旨在进一步评估暴露于V.harveyi后的生存率如何提高。在42天内测量抗体反应，通过用V.harveyi进行实验攻击来评估疫苗的效力。免疫相关基因IL1β的表达,TNFα,在攻击后(dpc)1、3和7天评估CD4、CD8、IgT和抗体水平。结果显示，（ONB+CS）+Vac组的抗体水平在浸没免疫和口服加强后始终高于其他组，在用V.harveyi攻击后，免疫相关基因的表达也升高。最终,该组表现出明显更高的相对生存率（RPS），为63％±10.5％，展示了ONB-CS-Vac复合物作为增强抗原摄取的有前途的浸没疫苗接种策略的潜力，刺激免疫反应，提高亚洲鲈鱼对弧菌病的存活率。
