Progressive multifocal leukoencephalopathy (PML) is a rare and lethal central nervous demyelinating disease caused by JC polyomavirus (JCV), particularly in patients with impaired immune system. The variation of JCV plays an important role in the pathogenesis of PML, including the recombination of non-coding regulatory region (NCCR), which is closely related to binding sites of transcription factors and affect the level of gene transcription. Nucleotide mutations in VP1 region determine the antigenicity and receptor specificity of JCV, play an important role in cell adsorption, immune-mediation and pathogenicity. In addition, immune cells are also involved in the pathogenesis of PML. T lymphocytes can recognize virus antigens, clear JCV, which are directly related to the prognosis of PML. B lymphocytes can serve as latent sites of JCV, and participate in viral transmission, replication, and coordination of the expression of transcription factors. This paper summarizes the roles of JCV variation and immune cells in pathogenesis of PML.
进行性多灶性脑白质病（PML）是由JC多瘤病毒（JCV）引起的一种罕见、致命的中枢神经脱髓鞘疾病，主要发生在免疫系统受损的患者中。JCV的致病变异在PML发病机制中发挥重要作用，包括：①JCV非编码调控区（NCCR）基因重组和转录因子结合位点的变化影响基因转录水平；②VP1区域核苷酸突变决定了JCV的抗原性和受体特异性，且在细胞吸附、免疫介导和致病性方面起着重要作用。此外，免疫细胞在PML发病中也发挥重要作用。T淋巴细胞能够识别病毒抗原、清除JCV，与PML预后直接相关；B淋巴细胞可以作为JCV潜伏位点，并在病毒传播、复制以及协调转录因子的表达中发挥作用。本文主要从JCV的致病变异和机体免疫两方面对PML的发病机制进行详细阐述。