Pumchan Ansaya, Sae-Ueng Udom, Prasittichai Chaiya, Sirisuay Soranuth, Areechon Nontawith, Unajak Sasimanas
Department of Biochemistry, Faculty of Science, Kasetsart University, 50 Ngam Wong Wan, Chatuchak, Bangkok 10900, Thailand.
Kasetsart Vaccines and Bio-Product Innovation Centre, Kasetsart University, 50 Ngam Wong Wan, Chatuchak, Bangkok 10900, Thailand.
Vaccines (Basel). 2022 Jul 25;10(8):1180. doi: 10.3390/vaccines10081180.
Generally, the injection method is recommended as the best efficient method for vaccine applications in fish. However, labor-intensive and difficult injection for certain fish sizes is always considered as a limitation to aquatic animals. To demonstrate the effectiveness of a novel oral delivery system for the piscine vaccine with nano-delivery made from nano clay, halloysite nanotubes (HNTs) and their modified forms were loaded with killed vaccines, and we determined the ability of the system in releasing vaccines in a mimic digestive system. The efficaciousness of the oral piscine vaccine nano-delivery system was evaluated for its level of antibody production and for the level of disease prevention in tilapia. Herein, unmodified HNTs (H) and modified HNTs [HNT-Chitosan (HC), HNT-APTES (HA) and HNT-APTES-Chitosan (HAC)] successfully harbored streptococcal bivalent vaccine with inactivated , designated as HF, HAF, HCF and HACF. The releasing of the loading antigens in the mimic digestive tract demonstrated a diverse pattern of protein releasing depending on the types of HNTs. Remarkably, HCF could properly release loading antigens with relevance to the increasing pH buffer. The oral vaccines revealed the greatest elevation of specific antibodies to serotype Ia in HCF orally administered fish and to some extent in serotype III. The efficacy of streptococcal disease protection was determined by continually feeding with HF-, HAF-, HCF- and HACF-coated feed pellets for 7 days in the 1st and 3rd week. HCF showed significant RPS (75.00 ± 10.83%) among the other tested groups. Interestingly, the HCF-treated group exhibited noticeable efficacy similar to the bivalent-vaccine-injected group (RPS 81.25 ± 0.00%). This novel nano-delivery system for the fish vaccine was successfully developed and exhibited appropriated immune stimulation and promised disease prevention through oral administration. This delivery system can greatly support animals' immune stimulation, which conquers the limitation in vaccine applications in aquaculture systems. Moreover, this delivery system can be applied to carrying diverse types of biologics, including DNA, RNA and subunit protein vaccines.
一般来说，注射法被认为是鱼类疫苗接种的最佳有效方法。然而，对于某些鱼的大小而言，劳动强度大且注射困难一直被视为水产动物疫苗接种的一个限制因素。为了证明一种由纳米粘土、埃洛石纳米管（HNTs）及其改性形式制成的用于鱼类疫苗的新型口服递送系统的有效性，我们将灭活疫苗装载到这些材料中，并测定了该系统在模拟消化系统中释放疫苗的能力。通过罗非鱼体内抗体产生水平和疾病预防水平，评估了口服鱼类疫苗纳米递送系统的有效性。在此，未改性的HNTs（H）和改性的HNTs [HNT-壳聚糖（HC）、HNT-APTES（HA）和HNT-APTES-壳聚糖（HAC）]成功装载了灭活的链球菌二价疫苗，分别命名为HF、HAF、HCF和HACF。在模拟消化道中装载抗原的释放显示，根据HNTs的类型不同，蛋白质释放模式也不同。值得注意的是，HCF能够随着pH缓冲液的增加而适当释放装载的抗原。口服疫苗显示，口服HCF的鱼体内针对血清型Ia的特异性抗体有最大程度的升高，对血清型III也有一定程度的升高。通过在第1周和第3周连续7天投喂包被有HF、HAF、HCF和HACF的饲料颗粒，测定了链球菌疾病保护的效果。在其他测试组中，HCF显示出显著的相对百分比存活率（RPS）（75.00 ± 10.83%）。有趣的是，HCF处理组表现出与二价疫苗注射组相似的显著效果（RPS 81.25 ± 0.00%）。这种用于鱼类疫苗的新型纳米递送系统被成功开发出来，并通过口服给药表现出适当的免疫刺激作用和有望的疾病预防效果。这种递送系统可以极大地支持动物的免疫刺激，克服了水产养殖系统中疫苗应用的限制。此外，这种递送系统可用于携带多种类型的生物制剂，包括DNA、RNA和亚单位蛋白疫苗。
