The heat shock protein 90 of Toxoplasma gondii is essential for invasion of host cells and tachyzoite growth

• Published in: Parasite (Paris) 2017, Vol.24, p.22-22
• Main Authors: Sun, Hongchao, Zhuo, Xunhui, Zhao, Xianfeng, Yang, Yi, Chen, Xueqiu, Yao, Chaoqun, Du, Aifang
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Protozoan - analysis; Antibodies, Protozoan - biosynthesis; Blotting, Western; Cercopithecus aethiops; Complementation; Differentiation; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique; Gene Knockout Techniques; Genetic Complementation Test; Heat shock protein 90; Heat shock proteins; Hot Temperature; HSP90 Heat-Shock Proteins - genetics; HSP90 Heat-Shock Proteins - immunology; HSP90 Heat-Shock Proteins - physiology; Hsp90 protein; Hydrogen-Ion Concentration; Invasion; Mice; Mice, Inbred BALB C; Parasites; Protozoa; Rabbits; Radioimmunoprecipitation Assay; Real-Time Polymerase Chain Reaction; Recombinant Proteins - genetics; Recombinant Proteins - immunology; Recombinant Proteins - isolation & purification; Replication; Signal transduction; Toxoplasma - chemistry; Toxoplasma - growth & development; Toxoplasma - pathogenicity; Toxoplasma - physiology; Toxoplasma gondii; Vero Cells; Vertebrates; Virulence
• ISSN: 1776-1042; 1252-607X; 1776-1042
• DOI: 10.1051/parasite/2017023

Toxoplasma gondii is an obligate intracellular apicomplexan parasite that infects almost all warm-blooded vertebrates. Heat shock proteins (HSP) regulate key signal transduction events in many organisms, and heat shock protein 90 (Hsp90) plays an important role in growth, development, and virulence in several parasitic protozoa. Here, we discovered increased transcription of the Hsp90 gene under conditions for bradyzoite differentiation, i.e. alkaline and heat shock conditions in vitro, suggesting that Hsp90 may be connected with bradyzoite development in T. gondii. A knockout of the TgHsp90 strain (ΔHsp90) and a complementation strain were constructed. The TgHsp90 knockout cells were found to be defective in host-cell invasion, were not able to proliferate in vitro in Vero cells, and did not show long-time survival in mice in vivo. These inabilities of the knockout parasites were restored upon complementation of TgHsp90. These data unequivocally show that TgHsp90 contributes to bradyzoite development, and to invasion and replication of T. gondii in host cells.