Laboratory of Emerging Infectious Diseases, Department of Frontier Veterinary Science, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan.
In Vitro Cell Dev Biol Anim. 2010 Jun;46(6):560-5. doi: 10.1007/s11626-009-9271-9. Epub 2010 Feb 5.
Human defensins play a fundamental role in the initiation of innate immune responses to some microbial pathogens. In this paper, we show that human alpha-defensin-5 displays a parasiticidal role against Toxoplasma gondii, the causative agent of toxoplasmosis. Exposure of the tachyzoite form of T. gondii to defensin induced aggregation and significantly reduced parasite viability in a concentration-dependent peptide. Pre-incubation of tachyzoites with human alpha-defensin-5 followed by exposure to a mouse embryonal cell line (NIH/3T3) significantly reduced T. gondii infection in these cells. Thus, human alpha-defensin-5 is an innate immune molecule that causes severe toxocity to T. gondii and plays an important role in reducing cellular infection. This is the first report showing that human alpha-defensin-5 causes aggregation, leading to Toxoplasma destruction.
人防御素在先天免疫反应对一些微生物病原体的启动中发挥着基本作用。在本文中，我们表明人α-防御素-5对弓形虫，即弓形体病的病原体具有寄生杀伤作用。防御素诱导的速殖子形式的弓形体聚集，并显著降低寄生虫活力在浓度依赖性肽。速殖子与人α-防御素-5孵育后再暴露于小鼠胚胎成纤维细胞系（NIH/3T3）中，可显著降低这些细胞中的弓形虫感染。因此，人α-防御素-5是一种先天免疫分子，它对弓形虫有严重的毒性作用，并在减少细胞感染方面起着重要作用。这是第一个报道表明人α-防御素-5引起聚集，导致弓形体破坏。
