Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.
BMC Vet Res. 2020 Nov 7;16(1):427. doi: 10.1186/s12917-020-02648-1.
H9N2 Low pathogenic avian influenza virus (LPAIV) raises public health concerns and its eradication in poultry becomes even more important in preventing influenza. AJSAF is a purified active saponin fraction from the stem bark of Albizzia julibrissin. In this study, AJSAF was evaluated for the adjuvant potentials on immune responses to inactivated H9N2 avian influenza virus vaccine (IH9V) in mice and chicken in comparison with commercially oil-adjuvant.
AJSAF significantly induced faster and higher H9 subtype avian influenza virus antigen (H9-Ag)-specific IgG, IgG1, IgG2a and IgG2b antibody titers in mice and haemagglutination inhibition (HI) and IgY antibody levels in chicken immunized with IH9V. AJSAF also markedly promoted Con A-, LPS- and H9-Ag-stimulated splenocyte proliferation and natural killer cell activity. Furthermore, AJSAF significantly induced the production of both Th1 (IL-2 and IFN-γ) and Th2 (IL-10) cytokines, and up-regulated the mRNA expression levels of Th1 and Th2 cytokines and transcription factors in splenocytes from the IH9V-immunized mice. Although oil-formulated inactivated H9N2 avian influenza vaccine (CH9V) also elicited higher H9-Ag-specific IgG and IgG1 in mice and HI antibody titer in chicken, this robust humoral response was later produced. Moreover, serum IgG2a and IgG2b antibody titers in CH9V-immunized mice were significantly lower than those of IH9V alone group.
AJSAF could improve antigen-specific humoral and cellular immune responses, and simultaneously trigger a Th1/Th2 response to IH9V. AJSAF might be a safe and efficacious adjuvant candidate for H9N2 avian influenza vaccine.
H9N2 低致病性禽流感病毒（LPAIV）引起了公众健康的关注，其在禽类中的根除对于预防流感变得更加重要。AJSAF 是从合欢树皮中提取的一种纯化的活性皂素级分。在这项研究中，与市售油佐剂相比，评估了 AJSAF 对灭活 H9N2 禽流感病毒疫苗（IH9V）在小鼠和鸡中免疫反应的佐剂潜力。
AJSAF 显著诱导更快和更高的 H9 亚型禽流感病毒抗原（H9-Ag）特异性 IgG、IgG1、IgG2a 和 IgG2b 抗体滴度在小鼠和血凝抑制（HI）和 IgY 抗体水平在鸡用 IH9V 免疫。AJSAF 还显著促进了 ConA、LPS 和 H9-Ag 刺激的脾细胞增殖和自然杀伤细胞活性。此外，AJSAF 还显著诱导了 Th1（IL-2 和 IFN-γ）和 Th2（IL-10）细胞因子的产生，并上调了 IH9V 免疫小鼠脾细胞中 Th1 和 Th2 细胞因子和转录因子的 mRNA 表达水平。虽然油佐剂灭活 H9N2 禽流感疫苗（CH9V）也在小鼠中引起了更高的 H9-Ag 特异性 IgG 和 IgG1 以及鸡的 HI 抗体滴度，但这种强烈的体液反应是后来产生的。此外，CH9V 免疫小鼠的血清 IgG2a 和 IgG2b 抗体滴度明显低于 IH9V 单独组。
AJSAF 可以提高抗原特异性体液和细胞免疫反应，并同时引发 IH9V 的 Th1/Th2 反应。AJSAF 可能是 H9N2 禽流感疫苗的一种安全有效的佐剂候选物。
