Main content area

Anti-parasitic effect on Toxoplasma gondii induced by a spider peptide lycosin-I

Tang, Yaqin, Hou, Shengjie, Li, Xianyao, Wu, Mengqi, Ma, Binbin, Wang, Zheng, Jiang, Jinying, Deng, Meichun, Duan, Zhigui, Tang, Xing, Liu, Yuan, Wang, Wenhua, Han, Xiaoqing, Jiang, Liping
Experimental parasitology 2019 v.198 pp. 17-25
Lycosa, Toxoplasma gondii, cell membranes, cytoplasm, drugs, fibroblasts, humans, interleukin-6, interleukin-8, mice, parasites, protozoal infections, quantitative polymerase chain reaction, tachyzoites, therapeutics, toxicity testing, toxoplasmosis, transmission electron microscopy, venoms
Toxoplasmosis is a widely distributed parasitic protozoan disease, caused by Toxoplasma gondii (T. gondii). High prevalence of toxoplasmosis and limitations of conventional treatments lead to a search for new therapeutic drugs. Lycosin-I is a linear peptide, derived from the venom of the spider Lycosa singoriensis. The aim of the present study was to determine the anti-parasitic effect of lycosin-Ι against T. gondii. In vitro, the anti-T. gondii activities of lycosin-Ι were evaluated by MTT assay, trypan blue exclusion assay, cell counting assay and plaque assay. Cytokines of IL-6 and IL-8 were measured by quantitative PCR. In addition, the structures of tachyzoites treated with lycosin-Ι were also observed by scanning and transmission electron microscopy. In vivo, mice were challenged with parasites treated by lycosin-I. The results revealed that lycosin-Ι had shown a significant ability to inhibit T. gondii invasion and proliferation. Cytokines of IL-6 and IL-8 were reduced by lycosin-Ι at transcription level in human foreskin fibroblast (HFF) cells infected with T. gondii tachyzoites, but they were increased compared to non-infected cells. For tachyzoites, lycosin-Ι induced their cell membrane alterations with formation of invaginations, some of them appeared to be vacuolated in their cytoplasm. Moreover, lycosin-Ι had prolonged the survival time of mice by controlling T. gondii proliferation. In conclusion, our present study provides the first evidence for anti-T. gondii by using the spider peptide lycosin-Ι. These findings suggest that lycosin-Ι is a potential alternative agent for the treatment of toxoplasmosis.