WHAT DO WE KNOW ABOUT PRIONS?

Prions are infectious agents made primarily of a misfolded host protein rather than nucleic acid, and they cause a distinctive group of fatal neurodegenerative diseases in humans and animals. Over four decades of research has established the core “protein-only” concept: a normal cellular prion protein can adopt an abnormal conformation that templates further misfolding, accumulates in the nervous system, and produces progressive brain damage after long incubation periods. What makes prions scientifically and practically important is not only their clinical severity but also their unusual biology: they can exist as different “strains” encoded by conformation, show strong species barriers, persist in the environment, and resist many routine decontamination methods.

朊病毒（Prions）是一类主要由错误折叠的宿主蛋白构成的感染因子，而非核酸，可致使人类与动物罹患一类独特的致死性神经退行性疾病。历经四十余年的研究，学界已确立核心的“纯蛋白”假说：正常的细胞型朊蛋白可转变为异常构象，该异常构象会作为模板诱导更多正常朊蛋白发生错误折叠，并在神经系统中累积，经过漫长的潜伏期后引发进行性脑损伤。朊病毒在科学与实践层面的重要性，不仅在于其临床危害性极强，更在于其独特的生物学特性：它们可存在多种由构象编码的“毒株”，表现出显著的物种屏障效应，可在环境中长期存活，且能抵抗多种常规去污消毒手段。