Parasitology Research

, Volume 93, Issue 1, pp 36–40 | Cite as

The involvement of the cysteine proteases of Clonorchis sinensis metacercariae in excystment

  • Shunyu Li
  • Young-Bae Chung
  • Byung-Suk Chung
  • Min-Ho Choi
  • Jae-Ran Yu
  • Sung-Tae Hong
Original Paper

Abstract

The effects of trypsin, bile, trypsin-bile, pepsin, dithiothreitol (DTT) and metacercarial excretory-secretory product (ESP) on the in vitro excystment of Clonorchis sinensis metacercariae were investigated. The majority of metacercariae excysted immediately in trypsin-bile in PBS solution, a process which was complete after 30 min of incubation. When incubated in metacercarial ESP in PBS, excystment was potentiated in the presence of 5 mM DTT, but was inhibited dose-dependently by a cysteine protease inhibitor, iodoacetic acid. Two active protease bands of 28 and 40 kDa were identified in the ESP of metacercariae by gelatin substrate SDS-PAGE. Scanning electron microscopy demonstrated that the larvae in solutions of DTT and ESP migrated through a small hole on the metacercarial wall, whereas larvae were liberated by entire wall disruption in trypsin solution. These results suggest that trypsin is a major extrinsic factor of the rapid excystment of C. sinensis metacercariae, and that endogenous cysteine proteases are also involved in metacercarial excystment.

References

  1. Chung YB, Kong Y, Joo IJ, Cho SY, Kang SY (1995) Excystment of Paragonimus westermani metacercariae by endogenous cysteine protease. J Parasitol 81:137–142PubMedGoogle Scholar
  2. Chung YB, Lee M, Yang HJ, Chung BS, Lee SY, Choi MH, Hong ST (2002) Characterization of partially purified 8 kDa antigenic protein of Clonorchis sinensis. Korean J Parasitol 40:83–88PubMedGoogle Scholar
  3. Fried B (1994) Metacercarial excystment of trematodes. Adv Parasitol 33:91–144Google Scholar
  4. Fried B, Stromberg BE (1985) In vitro excystment of metacercariae of Fascioloides magna (Trematoda). J Parasitol 71:263–264PubMedGoogle Scholar
  5. Fujino T, Ishii Y, Cho DW (1979) Surface ultrastructure of the tegument of Clonorchis sinensis newly excysted juveniles and adult worms. J Parasitol 65:579–590PubMedGoogle Scholar
  6. Heussen C, Dowdle EB (1980) Electrophoretic analysis of plasminogen activators in polyacrylamide gels containing sodium dodecyl sulfate and copolymerized substrates. Anal Biochem 102:196–202PubMedGoogle Scholar
  7. Intapan PM, Maleewong W (2001) In vitro excystation of Paragonimus heterotremus metacercariae. J Parasitol 87:1184–1186PubMedGoogle Scholar
  8. Irwin SWB (1983) In vitro excystment of the metacercaria of Maritrema arenaria (Digenea: Microphallidae). Int J Parasitol 13:191–196CrossRefGoogle Scholar
  9. McKerrow JH (1989) Parasite proteases. Exp Parasitol 68:111–115PubMedGoogle Scholar
  10. Ohyama F (1998) Effects of acid pepsin pretreatment, bile acids and reductants on the excystation of Clonorchis sinensis (Trematoda: Opisthorchiidae) metacercariae in vitro. Parasitol Int 47:29–39Google Scholar
  11. Seo BS (1959) The in vitro excystation of metacercariae of Clonorchis sinensis. New Med J 2:1389–1397Google Scholar
  12. Smoluk JL, Fried B (1994) Light microscopic observations of Echinostoma trivolvis (Trematoda) metacercariae during in vitro excystation. Parasitol Res 80:435–438PubMedGoogle Scholar
  13. Sohn WM, Seo M, Chai JY (2003) Surface ultrastructure of the adult stage of Acanthotrema felis (Trematoda: Heterophyidae). Korean J Parasitol 41:107–111PubMedGoogle Scholar

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Shunyu Li
    • 1
    • 2
  • Young-Bae Chung
    • 3
  • Byung-Suk Chung
    • 1
  • Min-Ho Choi
    • 1
  • Jae-Ran Yu
    • 4
  • Sung-Tae Hong
    • 1
  1. 1.Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine and Institute of Endemic DiseasesSeoul National University Medical Research CenterSeoul 110-799Korea
  2. 2.Department of Parasitology, College of MedicineYanbian UniversityYanjiP.R. China
  3. 3.Department of Parasitology, College of MedicineCheju National UniversityJeju 690-756Korea
  4. 4.Department of Parasitology, College of MedicineKonkuk UniversityChungju 380-701Korea

Personalised recommendations