Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, Ceredigion, SY23 3DA, Wales.
Parasitol Res. 2021 Mar;120(3):979-991. doi: 10.1007/s00436-021-07055-5. Epub 2021 Jan 27.
Fasciola hepatica (liver fluke), a significant threat to food security, causes global economic loss for the livestock industry and is re-emerging as a foodborne disease of humans. In the absence of vaccines, treatment control is by anthelmintics; with only triclabendazole (TCBZ) currently effective against all stages of F. hepatica in livestock and humans. There is widespread resistance to TCBZ and its detoxification by flukes might contribute to the mechanism. However, there is limited phase I capacity in adult parasitic helminths with the phase II detoxification system dominated by the soluble glutathione transferase (GST) superfamily. Previous proteomic studies have demonstrated that the levels of Mu class GST from pooled F. hepatica parasites respond under TCBZ-sulphoxide (TCBZ-SO) challenge during in vitro culture ex-host. We have extended this finding by exploiting a sub-proteomic lead strategy to measure the change in the total soluble GST profile (GST-ome) of individual TCBZ-susceptible F. hepatica on TCBZ-SO-exposure in vitro culture. TCBZ-SO exposure demonstrated differential abundance of FhGST-Mu29 and FhGST-Mu26 following affinity purification using both GSH and S-hexyl GSH affinity. Furthermore, a low or weak affinity matrix interacting Mu class GST (FhGST-Mu5) has been identified and recombinantly expressed and represents a new low-affinity Mu class GST. Low-affinity GST isoforms within the GST-ome was not restricted to FhGST-Mu5 with a second likely low-affinity sigma class GST (FhGST-S2) uncovered. This study represents the most complete Fasciola GST-ome generated to date and has supported the potential of subproteomic analyses on individual adult flukes.
肝片形吸虫（liver fluke），对食品安全构成重大威胁，给畜牧业造成全球性经济损失，且正在重新成为人类食源性疾病。在没有疫苗的情况下，治疗控制依赖于驱虫药；目前只有三氯苯达唑（triclabendazole，TCBZ）对所有阶段的肝片形吸虫在牲畜和人类中有效。该药物已广泛耐药，吸虫的解毒作用可能是其耐药机制之一。然而，成年寄生性蠕虫的一期能力有限，二期解毒系统主要由可溶性谷胱甘肽转移酶（glutathione transferase，GST）超家族主导。以前的蛋白质组学研究表明，在体外培养中，来自聚集的肝片形吸虫寄生虫的 Mu 类 GST 水平会对 TCBZ-亚砜（TCBZ-SO）的挑战作出响应。我们利用亚蛋白质组学先导策略，测量了在体外培养中接触 TCBZ-SO 时，个别对 TCBZ 敏感的肝片形吸虫总可溶性 GST 谱（GST-ome）的变化，从而扩展了这一发现。TCBZ-SO 暴露后，通过使用 GSH 和 S-己基 GSH 亲和性进行亲和纯化，发现 FhGST-Mu29 和 FhGST-Mu26 的丰度存在差异。此外，还鉴定并重组表达了一种低亲和力基质相互作用的 Mu 类 GST（FhGST-Mu5），它代表了一种新的低亲和力 Mu 类 GST。GST-ome 中的低亲和力 GST 同工型不仅限于 FhGST-Mu5，还发现了第二种可能的低亲和力 sigma 类 GST（FhGST-S2）。这项研究代表了迄今为止生成的最完整的 Fasciola GST-ome，并支持了对单个成年吸虫进行亚蛋白质组分析的潜力。
