College of Veterinary Medicine, Jeonbuk National University, Iksan, Republic of Korea.
Avian Pathol. 2020 Oct;49(5):486-495. doi: 10.1080/03079457.2020.1775782. Epub 2020 Jul 14.
H9N2, a low pathogenic avian influenza virus, causes significant economic losses in the poultry industry worldwide. Herein, we describe the construction of an attenuated Gallinarum (SG) strain for expression and delivery of H9N2 haemagglutinin (HA) 1 (SG-HA1), HA2 (SG-HA2) and/or the conserved matrix protein 2 ectodomain (SG-M2e). We demonstrated that recombinant SG strains expressing HA1, HA2 and M2e antigens were immunogenic and safe in a chicken model. Chickens (= 8) were vaccinated once orally with SG alone, SG-HA1, SG-HA2, SG-M2e, or mixture of SG-HA1, SG-HA2 and SG-M2e, or vaccinated once intramuscularly with an oil-adjuvant inactivated H9N2 vaccine. Our results demonstrated that vaccination with SG mutants encoding influenza antigens, administered individually or as a mixture, elicited significantly (< 0.05) greater antigen-specific humoral and cell-mediated immune responses in chickens compared with those vaccinated with SG alone. A conventional H9N2 vaccine induced significantly ( < 0.05) greater HA1 and HA2 antibody responses than SG-based H9N2 vaccine strains, but significantly ( < 0.05) less robust M2e-specific responses. Upon challenge with the virulent H9N2 virus on day 28 post-vaccination, chickens vaccinated with either the SG-based H9N2 or conventional H9N2 vaccines exhibited comparable lung inflammation and viral loads, although both were significantly lower ( < 0.05) than in the group vaccinated with SG alone. In conclusion, our results showed that SG-based vaccination stimulated efficient immune responses against virulent H9N2. Further studies are needed to fully develop this approach as a preventive strategy for low pathogenic avian influenza viruses affecting poultry. expressing HA1, HA2 and M2e antigens are immunogenic and safe. has dual function of acting as a delivery system and as a natural adjuvant. Vaccine constructs elicit specific humoral and cell-mediated immune responses.
H9N2 是一种低致病性禽流感病毒，它会给全球家禽业造成重大经济损失。在此，我们描述了一株减毒鸡源（SG）株的构建，该株可表达和递呈 H9N2 血凝素（HA）1（SG-HA1）、HA2（SG-HA2）和/或保守的基质蛋白 2 胞外域（SG-M2e）。我们证明了在鸡模型中，表达 HA1、HA2 和 M2e 抗原的重组 SG 株具有免疫原性和安全性。将鸡（=8）口服一次接种 SG 株、SG-HA1、SG-HA2、SG-M2e，或接种一次肌肉注射油佐剂灭活 H9N2 疫苗。结果表明，与单独接种 SG 株相比，接种编码流感抗原的 SG 突变株，无论是单独接种还是混合接种，都能显著（<0.05）增强鸡的抗原特异性体液和细胞免疫应答。传统的 H9N2 疫苗诱导的 HA1 和 HA2 抗体应答显著（<0.05）高于基于 SG 的 H9N2 疫苗株，但 M2e 特异性应答显著（<0.05）较弱。在接种后 28 天攻毒强毒 H9N2 病毒后，接种基于 SG 的 H9N2 或传统 H9N2 疫苗的鸡的肺部炎症和病毒载量相当，但均显著（<0.05）低于单独接种 SG 株的鸡。总之，我们的结果表明，基于 SG 的接种能刺激针对强毒 H9N2 的有效免疫应答。需要进一步研究以充分开发这种方法作为预防低致病性禽流感病毒感染家禽的策略。 表达 HA1、HA2 和 M2e 抗原具有免疫原性和安全性。 具有作为递送系统和天然佐剂的双重功能。疫苗构建物能诱导特异性体液和细胞免疫应答。
