Tsilibary Effie-Photini C, Souto Eric P, Kratzke Marian, James Lisa M, Engdahl Brian E, Georgopoulos Apostolos P
Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN, USA.
Department of Neuroscience, Medical School, University of Minnesota, Minneapolis, MN, USA.
Neurosci Insights. 2020 Jun 30;15:2633105520931966. doi: 10.1177/2633105520931966. eCollection 2020.
Protective antigen (PA) 63 (PA63) is a protein derived from the PA83 component contained in the anthrax vaccine. The anthrax vaccine ("Biothrax") was administered together with other vaccines to Gulf War veterans, about 35% of whom later developed a multisymptom disease (Gulf War Illness [GWI]), with prominent neurological/cognitive/mood symptoms, among others. The disease has been traditionally attributed to exposures to toxic chemicals during the war but other factors could be involved, including vaccines received. Of these, the anthrax vaccine is the most toxic. Here, we assessed directly the PA63 toxin's harmful effects on cultured neuroblastoma 2A (N2A) cells with respect to cell spreading, process formation, apoptosis, and integrity of cell membrane, cytoskeleton, and mitochondria. We found that, when added in N2A cultures, PA63 toxin led to decreased cell spreading and cell aggregation, leading to apoptosis. The mechanisms of PA63-induced cell damage included compromised cell membrane permeability indicated by enhanced access of propidium iodide in cells. In addition, signaling pathways leading to organization of N2A cytoskeleton were negatively affected, as both actin and microtubular networks were compromised. Finally, the mitochondrial membrane potential was impaired in specific assays. Altogether, these alterations led to apoptosis as a collective toxic effect of PA63 which was substantially reduced by the concomitant addition of specific antibodies against PA63.
保护性抗原（PA）63（PA63）是一种源自炭疽疫苗中所含PA83成分的蛋白质。炭疽疫苗（“BioThrax”）与其他疫苗一起接种给海湾战争退伍军人，其中约35%的人后来患上了一种多症状疾病（海湾战争综合症[GWI]），症状包括突出的神经/认知/情绪症状等。传统上，这种疾病被归因于战争期间接触有毒化学物质，但也可能涉及其他因素，包括接种的疫苗。其中，炭疽疫苗毒性最强。在此，我们直接评估了PA63毒素对培养的神经母细胞瘤2A（N2A）细胞在细胞铺展、突起形成、凋亡以及细胞膜、细胞骨架和线粒体完整性方面的有害影响。我们发现，当将PA63毒素添加到N2A培养物中时，会导致细胞铺展减少和细胞聚集，进而引发凋亡。PA63诱导细胞损伤的机制包括细胞膜通透性受损，表现为碘化丙啶进入细胞的能力增强。此外，导致N2A细胞骨架组织的信号通路受到负面影响，因为肌动蛋白和微管网络均受到破坏。最后，在特定检测中，线粒体膜电位受损。总之，这些改变导致了凋亡，这是PA63的一种集体毒性作用，而同时添加针对PA63的特异性抗体可使其显著降低。
