Orally administered fungal vaccines show promise for the prevention of infectious diseases. Edible mushrooms are deemed appropriate hosts to produce oral vaccines due to their low production cost and low risk of gene contamination. However, their low expression level of antigens has limited the potential development of oral vaccines using mushrooms. The low expression level might result from impurity of the transgenic mycelia since dikaryotic mycelia are commonly used as transformation materials. In this study, stable transgenic hepatitis B virus surface antigen (HBsAg) in Flammulina velutipes transformants was obtained by Agrobacterium-mediated transformation, followed by fruiting and basidiospore mating. The formation of HBsAg was detected by western blot analysis. The expression levels of HBsAg in transgenic F. velutipes fruiting bodies were (129.3±15.1), (110.9±1.7) and (161.1±8.5) ng/g total soluble protein. However, the values may be underestimated due to incomplete protein extraction. Two of the four pigs in the experimental group produced positive anti-HBsAg-specific IgG after being fed the HBsAg transgenic F. velutipes fruiting bodies for 20 weeks, while no anti-HBsAg antibody was detected in the control group. One of the positive pigs had HBsAg titres of 5.36 and 14.9 mIU/mL in weeks 10 and 14, respectively, but expression faded thereafter. The other positive pig displayed HBsAg titres of 9.75, 17.86 and 39.87 mIU/mL in weeks 14, 18 and 20, respectively. The successful immunogenicity in pigs fed transgenic F. velutipes fruiting bodies demonstrated the potential of using the fungus as an oral vaccine.

中文翻译：

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乙肝转基因金针菇口服疫苗的开发。

口服真菌疫苗显示出有望预防传染病。由于食用蘑菇生产成本低，基因污染风险低，被认为是生产口服疫苗的合适宿主。然而，它们的抗原低表达水平限制了使用蘑菇的口服疫苗的潜在发展。低表达水平可能是由于转基因菌丝体的杂质引起的，因为双核菌丝体通常被用作转化材料。在这项研究中，农杆菌获得了金针菇转化子中稳定的转基因乙型肝炎病毒表面抗原（HBsAg）。介导的转化，然后结实和担子孢子交配。通过蛋白质印迹分析检测到HBsAg的形成。转基因绒果子实体中HBsAg的表达水平为（129.3±15.1），（110.9±1.7）和（161.1±8.5）ng / g总可溶性蛋白。但是，由于蛋白质提取不完全，该值可能会被低估。实验组的四只猪中有两头在喂入HBsAg转基因天鹅绒菌后产生了抗HBs​​Ag特异性IgG阳性子实体20周，而对照组中未检测到抗HBsAg抗体。一只阳性猪在第10周和第14周的HBsAg滴度分别为5.36和14.9 mIU / mL，但此后表达减弱。另一只阳性猪在第14、18和20周的HBsAg滴度分别为9.75、17.86和39.87 mIU / mL。在饲喂转基因velutipes子实体的猪中成功的免疫原性证明了使用这种真菌作为口服疫苗的潜力。