Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830046, China.
Laboratory of Plant Stress Biology in Arid Land, College of Life Sciences, Xinjiang Normal University, Urumqi 830054, China.
J Vet Sci. 2021 May;22(3):e30. doi: 10.4142/jvs.2021.22.e30. Epub 2021 Mar 16.
New-generation adjuvants for foot-and-mouth disease virus (FMDV) vaccines can improve the efficacy of existing vaccines. Chinese medicinal herb polysaccharide possesses better promoting effects.
In this study, the aqueous extract from L. (AEAR), an immunoregulatory crude polysaccharide, was utilized as the adjuvant of inactivated FMDV vaccine to explore their immune regulation roles.
The mice in each group were subcutaneously injected with different vaccine formulations containing inactivated FMDV antigen adjuvanted with three doses (low, medium, and high) of AEAR or AEAR with ISA-206 adjuvant for 2 times respectively in 1 and 14 days. The variations of antibody level, lymphocyte count, and cytokine secretion in 14 to 42 days after first vaccination were monitored. Then cytotoxic T lymphocyte (CTL) response and antibody duration were measured after the second vaccination.
AEAR significantly induced FMDV-specific antibody titers and lymphocyte activation. AEAR at a medium dose stimulated Th1/Th2-type response through interleukin-4 and interferon-γ secreted by CD4⁺ T cells. Effective T lymphocyte counts were significantly elevated by AEAR. Importantly, the efficient CTL response was remarkably provoked by AEAR. Furthermore, AEAR at a low dose and ISA-206 adjuvant also synergistically promoted immune responses more significantly in immunized mice than those injected with only ISA-206 adjuvant and the stable antibody duration without body weight loss was 6 months.
These findings suggested that AEAR had potential utility as a polysaccharide adjuvant for FMDV vaccines.
口蹄疫病毒（FMDV）疫苗的新一代佐剂可以提高现有疫苗的效力。中药多糖具有更好的促进作用。
本研究以免疫调节粗多糖 L.（AEAR）的水提物为佐剂，与灭活 FMDV 抗原联合，探讨其免疫调节作用。
每组小鼠分别皮下注射不同的疫苗制剂，包含灭活 FMDV 抗原，佐剂为 AEAR 的低、中、高三个剂量或 AEAR 与 ISA-206 佐剂。在首次接种后 14 天内监测抗体水平、淋巴细胞计数和细胞因子分泌的变化。然后在第二次接种后测量细胞毒性 T 淋巴细胞（CTL）反应和抗体持续时间。
AEAR 显著诱导 FMDV 特异性抗体滴度和淋巴细胞激活。AEAR 中剂量通过 CD4⁺T 细胞分泌的白细胞介素-4 和干扰素-γ刺激 Th1/Th2 型反应。AEAR 显著增加有效的 T 淋巴细胞计数。重要的是，AEAR 可显著引发有效的 CTL 反应。此外，AEAR 低剂量和 ISA-206 佐剂联合使用也比单独使用 ISA-206 佐剂更显著地促进免疫应答，抗体持续时间稳定，无体重减轻，可持续 6 个月。
这些发现表明 AEAR 具有作为 FMDV 疫苗多糖佐剂的潜力。
