Zhao Kai, Gao Yuan, Hu Gaowei, Wang Lei, Cui Shangjin, Jin Zheng
Institute of Nanobiomaterials and Immunology, School of Life Science, Taizhou University, Taizhou 318000, China.
State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Vaccines (Basel). 2021 Sep 16;9(9):1027. doi: 10.3390/vaccines9091027.
Porcine (PPV) is the most important infectious agent causing infertility in pigs, which can be prevented by routine vaccination. Successful vaccination depends on the association with potent adjuvants that can enhance the immunogenicity of antigen and activate the immune system. Polysaccharide adjuvant has low toxicity and high safety, and they can enhance the humoral, cellular and mucosal immune responses. In the present study, we prepared the VP2 protein subunit vaccine against PPV (PPV/VP2/N-2-HACC) using water-soluble -2-Hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC) as the vaccine adjuvant, and the ability of the PPV/VP2/N-2-HACC to induce immune responses and protect sows from PPV infection was evaluated. In vivo immunization showed that the sows immunized with the PPV/VP2/N-2-HACC by intramuscular injection produced higher HI antibody levels and long-term immune protection compared with the other groups, while the subunit vaccine did not stimulate the proliferation of CD4+ and CD8+ T lymphocytes to trigger the secretion of higher levels of IL-2, IL-4, IFN-α, IFN-β, and IFN-γ, indicating that the PPV/VP2/N-2-HACC mainly induced humoral immunity rather than cellular immunity. PPV was not detected in the viscera of the sows immunized with the PPV/VP2/N-2-HACC, and the protective efficacy was 100%. Collectively, our findings suggested that the N-2-HACC was a potential candidate adjuvant, and the PPV/VP2/N-2-HACC had immense application value for the control of PPV.
猪细小病毒（PPV）是引起猪不育的最重要的感染因子，可通过常规疫苗接种预防。成功的疫苗接种取决于与能增强抗原免疫原性并激活免疫系统的有效佐剂的联合使用。多糖佐剂毒性低、安全性高，可增强体液免疫、细胞免疫和黏膜免疫反应。在本研究中，我们以水溶性的-2-羟丙基三甲基氯化铵壳聚糖（N-2-HACC）作为疫苗佐剂，制备了抗PPV的VP2蛋白亚单位疫苗（PPV/VP2/N-2-HACC），并评估了PPV/VP2/N-2-HACC诱导免疫反应及保护母猪免受PPV感染的能力。体内免疫试验表明，与其他组相比，肌肉注射PPV/VP2/N-2-HACC免疫的母猪产生了更高的血凝抑制（HI）抗体水平和长期免疫保护，而亚单位疫苗未刺激CD4+和CD8+T淋巴细胞增殖以触发更高水平的白细胞介素-2（IL-2）、白细胞介素-4（IL-4）、干扰素-α（IFN-α）、干扰素-β（IFN-β）和干扰素-γ（IFN-γ）分泌，表明PPV/VP2/N-2-HACC主要诱导体液免疫而非细胞免疫。在接种PPV/VP2/N-2-HACC的母猪内脏中未检测到PPV，保护效力为100%。总体而言，我们的研究结果表明N-2-HACC是一种潜在的候选佐剂，PPV/VP2/N-2-HACC在控制PPV方面具有巨大的应用价值。
