Arrieta-Mendoza Darwuin, Garces Bruno, Hidalgo Alejandro A, Neira Victor, Ramirez Galia, Neira-Carrillo Andrónico, Bucarey Sergio A
Doctoral Program in Forestry, Agricultural and Veterinary Sciences, South Campus, University of Chile, Av. Santa Rosa 11315, La Pintana, Santiago 8820808, Chile.
Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, 2320 Sazié, Santiago 8320000, Chile.
Vaccines (Basel). 2024 May 17;12(5):550. doi: 10.3390/vaccines12050550.
This work evaluated in vivo an experimental-multivalent-vaccine (EMV) based on three Porcine Respiratory Complex (PRC)-associated antigens: Porcine Circovirus Type 2 (PCV2), (Mhyop) and (Mhyor), microencapsulated with sulfated chitosan (M- ChS + PRC-antigens), postulating chitosan sulphate (ChS) as a mimetic of the heparan sulfate receptor used by these pathogens for cell invasion. The EMV was evaluated physicochemically by SEM (Scanning-Electron-Microscopy), EDS (Energy-Dispersive-Spectroscopy), Pdi (Polydispersity-Index) and zeta potential. Twenty weaned pigs, distributed in four groups, were evaluated for 12 weeks. The groups 1 through 4 were as follows: 1-EMV intramuscular-route (IM), 2-EMV oral-nasal-route (O/N), 3-Placebo O/N (M-ChS without antigens), 4-Commercial-vaccine PCV2-Mhyop. qPCR was used to evaluate viral/bacterial load from serum, nasal and bronchial swab and from inguinal lymphoid samples. Specific humoral immunity was evaluated by ELISA. M-ChS + PRC-antigens measured between 1.3-10 μm and presented low Pdi and negative zeta potential, probably due to S (4.26%). Importantly, the 1-EMV protected 90% of challenged animals against PCV2 and Mhyop and 100% against Mhyor. A significant increase in antibody was observed for Mhyor (1-EMV and 2-EMV) and Mhyop (2-EMV), compared with 4-Commercial-vaccine. No difference in antibody levels between 1-EMV and 4-Commercial-vaccine for PCV2-Mhyop was observed. Conclusion: The results demonstrated the effectiveness of the first EMV with M-ChS + PRC-antigens in pigs, which were challenged with Mhyor, PCV2 and Mhyop, evidencing high protection for Mhyor, which has no commercial vaccine available.
本研究在体内评估了一种基于三种与猪呼吸道复合体（PRC）相关抗原的实验性多价疫苗（EMV）：猪圆环病毒2型（PCV2）、猪支原体肺炎（Mhyop）和猪鼻支原体（Mhyor），这些抗原用硫酸化壳聚糖微囊化（M-ChS + PRC抗原），推测硫酸化壳聚糖（ChS）可模拟这些病原体用于细胞入侵的硫酸乙酰肝素受体。通过扫描电子显微镜（SEM）、能谱分析（EDS）、多分散指数（Pdi）和zeta电位对EMV进行了物理化学评估。将20头断奶仔猪分为四组，进行了12周的评估。第1组至第4组如下：1-EMV肌肉注射途径（IM），2-EMV口鼻途径（O/N），3-安慰剂O/N（不含抗原的M-ChS），4-商业疫苗PCV2-Mhyop。采用qPCR评估血清、鼻拭子、支气管拭子和腹股沟淋巴样样本中的病毒/细菌载量。通过ELISA评估特异性体液免疫。M-ChS + PRC抗原的粒径在1.3-10μm之间，Pdi较低，zeta电位为负，这可能归因于硫（4.26%）。重要的是，1-EMV可保护90%的受攻击动物免受PCV2和Mhyop感染，100%免受Mhyor感染。与4-商业疫苗相比，观察到Mhyor（1-EMV和2-EMV）和Mhyop（2-EMV）的抗体显著增加。在PCV2-Mhyop方面，未观察到1-EMV和4-商业疫苗之间抗体水平的差异。结论：结果证明了第一种含M-ChS + PRC抗原的EMV对感染Mhyor、PCV2和Mhyop的猪具有有效性，证明了其对尚无商业疫苗的Mhyor具有高度保护作用。
