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Forward Genetics Screens Using Macrophages to Identify Toxoplasma gondii Genes Important for Resistance to IFN-γ-Dependent Cell Autonomous Immunity
Published on: March 12, 2015
Parasiticidal activity of human alpha-defensin-5 against Toxoplasma gondii
Tetsuya Tanaka1, Md Morshedur Rahman, Banzragch Battur
1Laboratory of Emerging Infectious Diseases, Department of Frontier Veterinary Science, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan.
Abstract:
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.
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