Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-06T08:05:09.472Z Has data issue: false hasContentIssue false

The immunogenicity of Echinococcus granulosus antigen 5 is determined by its post-translational modifications

Published online by Cambridge University Press:  11 July 2005

C. LORENZO
Affiliation:
Cátedra de Inmunología, Facultad de Química, UDELAR, Instituto de Higiene, Av. A. Navarro 3051, piso 2, 11600 Montevideo, Uruguay
J. A. LAST
Affiliation:
Pulmonary/Critical Care Medicine, School of Medicine, University of California, Davis, CA, USA
G. G. GONZÁLEZ-SAPIENZA
Affiliation:
Cátedra de Inmunología, Facultad de Química, UDELAR, Instituto de Higiene, Av. A. Navarro 3051, piso 2, 11600 Montevideo, Uruguay

Abstract

Since its early introduction as a marker for the immunodiagnosis of hydatid disease, antigen 5 (Ag5) has been regarded as one of the more relevant antigens of Echinococcus granulosus, and it is still widely used in different confirmation techniques. In this work we prepared 2 recombinant forms of the antigen, namely, rAg5 (corresponding to the unprocessed polypeptide chain of the antigen) and rAg5-38s (corresponding to its 38 kDa subunit). Their antigenicities were compared to that of the native antigen using a human serum collection. There was a major drop in the reactivity of the sera, particularly against rAg5-38s, which was confirmed by analysis of the cross-reactivity of 2 panels of monoclonal antibodies specific for rAg5-38s and the native antigen. Using the chemically deglycosylated native antigen, we demonstrated that the reduced antigenicity of the recombinants is due to the loss of the sugar determinants, and not to their misfolding. Inhibition experiments using phosphorylcholine confirmed that this moiety also contributes to the reactivity of the antigen, but to a much lesser extent. The presence of immunodominant highly cross-reactive glycan moieties in the Ag5 molecule may involve a parasite evasion mechanism.

Type
Research Article
Copyright
© 2005 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Barbieri, M., Sterla, S., Battistoni, J. and Nieto, A. ( 1993). High performance latex reagent for hydatid serology using an Echinococcus granulosus lipoprotein antigen fraction purified from cyst fluid in one step. International Journal for Parasitology 23, 565572.CrossRefGoogle Scholar
Capron, A., Vernes, A. and Biguet, J. ( 1967). Le Diagnostic Immuno-Electrophorétique de l'Hydatidose. SIMEP, Lyon.
Chamekh, M., Facon, B., Dissous, C., Haque, A. and Capron, A. ( 1990). Use of a monoclonal antibody specific for a protein epitope of Echinococcus granulosus antigen 5 in a competitive antibody radioimmunoassay for diagnosis of hydatid disease. Journal of Immunological Methods 134, 129137.CrossRefGoogle Scholar
Chamekh, M., Gras-Masse, H., Bossus, M., Facon, B., Dissous, C., Tartar, A. and Capron, A. ( 1992). Diagnostic value of a synthetic peptide derived from Echinococcus granulosus recombinant protein. Journal of Clinical Investigation 89, 458464.CrossRefGoogle Scholar
Di Felice, G., Pini, C., Afferni, C. and Vicari, G. ( 1986). Purification and partial characterization of the major antigen of Echinococcus granulosus (antigen 5) with monoclonal antibodies. Molecular and Biochemical Parasitology 20, 133142.CrossRefGoogle Scholar
Edge, A. S. ( 2003). Deglycosylation of glycoproteins with trifluoromethanesulphonic acid: elucidation of molecular structure and function. The Biochemical Journal 376, 339350.CrossRefGoogle Scholar
Gonzalez, G., Orn, A., Cazzulo, J. J. and Gronvik, K. O. ( 1994). Production and characterization of monoclonal antibodies against the major cysteine proteinase of Trypanosoma cruzi. Scandinavian Journal of Immunology 40, 389394.CrossRefGoogle Scholar
Gonzalez, G., Spinelli, P., Lorenzo, C., Hellman, U., Nieto, A., Willis, A. and Salinas, G. ( 2000). Molecular characterization of P-29, a metacestode-specific component of. Molecular and Biochemical Parasitology 105, 177184.CrossRefGoogle Scholar
Harnett, W. and Harnett, M. M. ( 1999). Phosphorylcholine: friend or foe of the immune system? Immunology Today 20, 125129.Google Scholar
Haslam, S. M., Khoo, K. H., Houston, K. M., Harnett, W., Morris, H. R. and Dell, A. ( 1997). Characterisation of the phosphorylcholine-containing N-linked oligosaccharides in the excretory-secretory 62 kDa glycoprotein of Acanthocheilonema viteae. Molecular and Biochemical Parasitology 85, 5366.CrossRefGoogle Scholar
Hokke, C. H. and Deelder, A. M. ( 2001). Schistosome glycoconjugates in host-parasite interplay. Glycoconjugate Journal 18, 573587.CrossRefGoogle Scholar
Khoo, K. H. and Dell, A. ( 2001). Glycoconjugates from parasitic helminths: structure diversity and immunobiological implications. Advances in Experimental Medicine and Biology 491, 185205.CrossRefGoogle Scholar
Lightowlers, M. W., Liu, D. Y., Haralambous, A. and Rickard, M. D. ( 1989). Subunit composition and specificity of the major cyst fluid antigens of Echinococcus granulosus. Molecular and Biochemical Parasitology 37, 171182.CrossRefGoogle Scholar
Liu, D., Rickard, M. D. and Lightowlers, M. W. ( 1993). Analysis of taeniid antigens using monoclonal antibodies to Echinococcus granulosus antigen 5 and antigen B. Parasitology Research 79, 8285.CrossRefGoogle Scholar
Lorenzo, C., Salinas, G., Brugnini, A., Wernstedt, C., Hellman, U. and Gonzalez-Sapienza, G. ( 2003). Echinococcus granulosus antigen 5 is closely related to proteases of the trypsin family. The Biochemical Journal 369, 191198.CrossRefGoogle Scholar
March, F., Enrich, C., Mercader, M., Sanchez, F., Munoz, C., Coll, P. and Prats, G. ( 1991). Echinococcus granulosus: antigen characterization by chemical treatment and enzymatic deglycosylation. Experimental Parasitology 73, 433439.CrossRefGoogle Scholar
Shepherd, J. and McManus, D. ( 1987). Specific and cross-reactive antigens of Echinococcus granulosus hydatid cyst fluid. Molecular and Biochemical Parasitology 25, 143154.CrossRefGoogle Scholar
Swets, J. A. ( 1988). Measuring the accuracy of diagnostic systems. Science 240, 12851293.CrossRefGoogle Scholar
Tomasz, A. ( 1967). Choline in the cell wall of a bacterium: novel type of polymer-linked choline in Pneumococcus. Science 157, 694697.CrossRefGoogle Scholar
Yarzabal, L. A., Bout, D. T., Naquira, F. R. and Capron, A. R. ( 1977). Further observations on the specificity of antigen 5 of Echinococcus granulosus. Journal of Parasitology 63, 495499.CrossRefGoogle Scholar