Univ. Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France.
Univ. Paris 7, Inserm, UMR, 1162 Paris, France.
Genes (Basel). 2019 Aug 31;10(9):667. doi: 10.3390/genes10090667.
Many pathogens (virus, bacteria, fungi, or parasites) have developed a wide variety of mechanisms to evade their host immune system. The budding yeast has successfully been used to decipher some of these immune evasion strategies. This includes the -acting mechanism that limits the expression of the oncogenic Epstein-Barr virus (EBV)-encoded EBNA1 and thus of antigenic peptides derived from this essential but highly antigenic viral protein. Studies based on budding yeast have also revealed the molecular bases of epigenetic switching or recombination underlying the silencing of all except one members of extended families of genes that encode closely related and highly antigenic surface proteins. This mechanism is exploited by several parasites (that include pathogens such as , , , or ) to alternate their surface antigens, thereby evading the immune system. Yeast can itself be a pathogen, and pathogenic fungi such as , which is phylogenetically very close to , have developed stealthiness strategies that include changes in their cell wall composition, or epitope-masking, to control production or exposure of highly antigenic but essential polysaccharides in their cell wall. Finally, due to the high antigenicity of its cell wall, yeast has been opportunistically exploited to create adjuvants and vectors for vaccination.
许多病原体（病毒、细菌、真菌或寄生虫）已经发展出各种各样的机制来逃避宿主的免疫系统。芽殖酵母已被成功用于破译其中一些免疫逃避策略。其中包括作用机制，该机制限制了致癌性 Epstein-Barr 病毒 (EBV) 编码的 EBNA1 的表达，从而限制了源自这种必需但高度抗原的病毒蛋白的抗原肽的表达。基于芽殖酵母的研究还揭示了表观遗传开关或重组的分子基础，这些开关或重组是沉默除一个成员之外的、编码密切相关和高度抗原表面蛋白的扩展基因家族的基础。这种机制被几种寄生虫（包括病原体，如、、、或）利用，以交替其表面抗原，从而逃避免疫系统。酵母本身可能是一种病原体，而亲缘关系非常密切的病原真菌，如，已经发展出了隐身策略，包括改变细胞壁成分或表位掩盖，以控制其细胞壁中高度抗原但必需的多糖的产生或暴露。最后，由于其细胞壁的高抗原性，酵母被机会主义地利用来创建佐剂和疫苗载体。
