Molecular escape mechanisms of Theileria parasites

• Project/Area Number: 07406019
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Basic veterinary science/Basic zootechnical science
• Research Institution: Hokkaido University
• Principal Investigator: ONUMA Misao Graduate School of Vet.Med., Hokkaido University, Professor, 大学院・獣医学研究科, 教授 (70109510)
• Co-Investigator(Kenkyū-buntansha): OHASHI Kazuhiko Graduate School of Vet.Med., Hokkaido University, Inst., 大学院・獣医学研究科, 助手 (90250498) ; SUGIMOTO Chihiro Graduate School of Vet.Med., Hokkaido University, Assoc.Prof., 大学院・獣医学研究科, 助教授 (90231373)
• Project Period (FY): 1995 – 1998
• Project Status: Completed (Fiscal Year 1998)
• Budget Amount: ¥12,400,000 (Direct Cost: ¥12,400,000); Fiscal Year 1998: ¥3,600,000 (Direct Cost: ¥3,600,000); Fiscal Year 1997: ¥3,600,000 (Direct Cost: ¥3,600,000); Fiscal Year 1996: ¥5,200,000 (Direct Cost: ¥5,200,000)
• Keywords: Theileria parasites / piroplasm / evasion mechanism / parasite genotype / tick / 原虫表面抗原遺伝子 / ダニ体内の有性生殖 / 持続感染 / 抗原多型性 / バキュロウィルス発現系 / 表面抗原 / PCR

Research Abstract

Theileria sergenti is a tick-borne protozoa of cattle. T.sergenti infected calves show persistent infection, possibly over their life span, but the mechanisms by which the parasites evade host defense mechanisms are not clearly understood. The complete life-cycle of T.sergenti in the mammalian host and tick vector remains unclear, the parasite may undergo a sexual stage in tick gut. To study the population changes during persistent infection in cattle and vector ticks, we have inoculated T.sergenti which consist of 2 parasite populations with C and I type allele of p32 and analyzed the population changes by allele-specific PCR to differentiate between individual types of parasites. Changes in a dominant parasite population were demonstrated during transmission from calves to the tick vector and from infected ticks to calves. The antigenic diversity which may be produced at the sexual stage in tick vector. The analysis of chromosome provide us the basic information to study the generation of genetic and antigenic polymorphism.
Chromosome analysis of T.sergenti showed 4 chromosomes. From the results of Southern blot analysis, p32 gene was located on the 1st chromosome, p23, heat shock protein 70 (HSP 70) and cystein proteinase genes were on the chromosome 2 and ribosomal RNA gene was on chromosomes 1 and 3/4.

Research Products

• [Publications] Murenga A.: "Molecular characterization of a Haemaphysalis longicornis tick salivary gland-associated 29 kilodalton in rabbits." Infect. Immun.in press. (1999)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Kawazu, S.: "Phylogenetic relationships of the benign Theileria species in cattle and Asian buffalo based on the major piroplasm surface protein (p33-34) gene sequence." Int.J.Parasitol.in press. (1999)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Sako, Y.: "Molecular cloning and characterization of 23kDa piroplasm surface proteins of Theileria sergenti and T.buffeli." Int.J.Parasitol.in press. (1999)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Sako, Y.: "Expression of major piroplasm surface protein of Theileria sergenti in sporozoite stage." J.Vet.Med.Sci.in press. (1999)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Sako, Y.: "Cloning of a cystein proteinase gene of Theileria sergenti." J.Vet.Med.Sci.in press. (1999)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Murenga A.: "Molecular characterization of a Haemaphysalis longicornis tick salivary gland-ssociated 29 kilodalton in rabbits." Infect.Immun.(in press). (1999)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Kawazu, S.: "Phylogenetic relationships of the benign Theileria species in cattle and Asian buffalo based on the major piroplasm surface protein (p33-34) gene sequence." Int.J.Parasiol.(in press). (1999)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Sako, Y.: "Molecular cloning and characterization of 23kDa piroplasm surface proteins of Theileria sergenti and T.buffeli" Int.J.Parasitol.(in press). (1999)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Sako, Y.: "Expression of a major piroplasm surface protein of Theileria sergenti in sporozoite stage." J.Vet.Med.Sci.(in press). (1999)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Sako, Y.: "Cloning of a cystein proteinase gene of Theileria sergenti." J.Vet.Med.Sci.(in press). (1999)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Murenga A.: "Molecular characterization of a Haemaphysalis longicornis tick salivary gland-associated 29 kilodalton in rabbits." Infect.Immun.(in press). (1999)
• [Publications] Kawazu,S.: "Phylogenetic relationships of the benign Theileria species in cattle and Asian buffalo based on the major piroplasm surface protein (p33-34) gene sequence." Int.J.Parasitol.(in press). (1999)
• [Publications] Sako,Y.: "Molecular cloning and characterization of 23kDa piroplasm surface proteins of Theileria sergenti and T.buffeli." Int.J.Parasitol.(in press). (1999)
• [Publications] Sako,Y.: "Expression of a major piroplasm surface protein of Theileria sergenti in sporozoite stage." J.Vet.Med.Sci.(in press). (1999)
• [Publications] Sako,Y.: "Cloning of a cystein proteinase gene of Theileria sergenti." J.Vet.Med.Sci.(in press). (1999)
• [Publications] Iwasaki T.: "Differentiation and quantification of Theileria sergenti piroplasm types using type-specific monoclonal antibodies." J.Vet.Med.Sci.(in press). (1998)
• [Publications] Onuma M.: "Theileria parasite infection in East Asia and control of the disease." Comp.Immun.Microbiol.Infect.Dis.(in press). (1998)
• [Publications] Kakuda T.: "Analysis of immunodominant piroplasm surface protein genes of benign Theileria parasites distributed in China and Korea by allele-specific polymerase chain reaction." J.Vet.Med.Sci.60. 237-239 (1998)
• [Publications] Wang CT.: "Survey of Theileria parasite infection in cattle in Taiwan." J.Vet.Med.Sci.60. 253-255 (1998)
• [Publications] Kubota S., et al.: "Analysis of immunodominant piroplasm surface antigen alleles in mixed populations of T. sergenti and T. Buffeli." Int.J.Parasitol.26. 741-747 (1996)
• [Publications] Kubota S., et al.: "Population dynamics of T. sergenti in persistently infected cattle and vector ticks analysed by PCR." Parasitology. 112. 437-442 (1996)
• [Publications] Watarai S., et al.: "Isolaton and characterization of gangliosides from T. sergenti." J.Vet.Med.Sci.58. 1099-1105 (1996)
• [Publications] Kubota,S.: "Population dynamics of T.serganti in persisteutly infeted catle and vector ticks ovalyged by PCR." Parasitology. (In press). (1996)
• [Publications] Kubota,S.: "Parasite pogulation oualysis ofT.sergenti and T.bufeli by allele-sgecitic PCR for immuadominaut Piroplasiu gurpel" Intenational J for parasitology. (In press). (1996)