Abstract
A 24-kDa recombinant protein from Trypanosoma cruzi (rTc24) was evaluated by enzyme-linked immunosorbent assay (ELISA) and Western blot (immunoblot) tests to identify treated chagasic patients considered parasitologically cured on the basis of persistently negative tests of hemocultures and lytic antibodies. Some of these patients were termed dissociated because their sera, although negative by the complement-mediated lysis test, were positive by conventional serology. The negative lysis test indicates the absence of active infection after specific treatment, but this assay requires live and infectious parasites and cannot be used easily in a laboratory routine. Here we tested rTc24 by ELISA and Western blotting as an alternative for the complement-mediated lysis test. For the group of patients with active infection despite the treatment (uncured patients), all the sera tested recognized rTc24 in both tests. For the dissociated patients, approximately 80% of the sera did not react with rTc24 in the ELISA or in Western blots, in agreement with the negative complement-mediated lysis tests. Thus, the 24-kDa T. cruzi recombinant antigen, when used for initial trials to evaluate cure of chagasic patients submitted to specific treatment, will allow the identification of most, but not all, cases.
Full Text
The Full Text of this article is available as a PDF (436.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Almeida I. C., Krautz G. M., Krettli A. U., Travassos L. R. Glycoconjugates of Trypanosoma cruzi: a 74 kD antigen of trypomastigotes specifically reacts with lytic anti-alpha-galactosyl antibodies from patients with chronic Chagas disease. J Clin Lab Anal. 1993;7(6):307–316. doi: 10.1002/jcla.1860070603. [DOI] [PubMed] [Google Scholar]
- Almeida I. C., Milani S. R., Gorin P. A., Travassos L. R. Complement-mediated lysis of Trypanosoma cruzi trypomastigotes by human anti-alpha-galactosyl antibodies. J Immunol. 1991 Apr 1;146(7):2394–2400. [PubMed] [Google Scholar]
- Andrade S. G., Freitas L. A., Peyrol S., Pimentel A. R., Sadigursky M. Trypanosoma cruzi antigens detected by immunoelectron microscopy in the spleen of mice serologically positive but parasitologically cured by chemotherapy. (Preliminary report). Rev Soc Bras Med Trop. 1988 Jan-Mar;21(1):41–42. doi: 10.1590/s0037-86821988000100010. [DOI] [PubMed] [Google Scholar]
- Engman D. M., Krause K. H., Blumin J. H., Kim K. S., Kirchhoff L. V., Donelson J. E. A novel flagellar Ca2+-binding protein in trypanosomes. J Biol Chem. 1989 Nov 5;264(31):18627–18631. [PubMed] [Google Scholar]
- Engvall E., Perlmann P. Enzyme-linked immunosorbent assay (ELISA). Quantitative assay of immunoglobulin G. Immunochemistry. 1971 Sep;8(9):871–874. doi: 10.1016/0019-2791(71)90454-x. [DOI] [PubMed] [Google Scholar]
- Ferreira H. de O. Tratamento da forma indeterminada da doença de Chagas com nifurtimox e benzonidazol. Rev Soc Bras Med Trop. 1990 Oct-Dec;23(4):209–211. doi: 10.1590/s0037-86821990000400005. [DOI] [PubMed] [Google Scholar]
- Galvao L. M., Nunes R. M., Cançado J. R., Brener Z., Krettli A. U. Lytic antibody titre as a means of assessing cure after treatment of Chagas disease: a 10 years follow-up study. Trans R Soc Trop Med Hyg. 1993 Mar-Apr;87(2):220–223. doi: 10.1016/0035-9203(93)90501-g. [DOI] [PubMed] [Google Scholar]
- Gazzinelli R. T., Galvao L. M., Krautz G., Lima P. C., Cancado J. R., Scharfstein J., Krettli A. U. Use of Trypanosoma cruzi purified glycoprotein (GP57/51) or trypomastigote-shed antigens to assess cure for human Chagas' disease. Am J Trop Med Hyg. 1993 Nov;49(5):625–635. doi: 10.4269/ajtmh.1993.49.625. [DOI] [PubMed] [Google Scholar]
- Joiner K. A., daSilva W. D., Rimoldi M. T., Hammer C. H., Sher A., Kipnis T. L. Biochemical characterization of a factor produced by trypomastigotes of Trypanosoma cruzi that accelerates the decay of complement C3 convertases. J Biol Chem. 1988 Aug 15;263(23):11327–11335. [PubMed] [Google Scholar]
- Kipnis T. L., Krettli A. U., Dias da Silva W. Transformation of trypomastigote forms of Trypanosoma cruzi into activators of alternative complement pathway by immune IgG fragments. Scand J Immunol. 1985 Aug;22(2):217–226. doi: 10.1111/j.1365-3083.1985.tb01874.x. [DOI] [PubMed] [Google Scholar]
- Krautz G. M., Coutinho M. G., Galvão L. M., Cançado J. R., Krettli A. U. Antígenos solúveis liberados por tripomastigotas de Trypanosoma cruzi utilizados no teste de ELISA para detectar cura em pacientes chagásicos após tratamento específico. Rev Soc Bras Med Trop. 1994 Oct-Dec;27(4):199–207. doi: 10.1590/s0037-86821994000400001. [DOI] [PubMed] [Google Scholar]
- Krettli A. U., Brener Z. Resistance against Trypanosoma cruzi associated to anti-living trypomastigote antibodies. J Immunol. 1982 May;128(5):2009–2012. [PubMed] [Google Scholar]
- Krettli A. U., Cançado J. R., Brener Z. Effect of specific chemotherapy on the levels of lytic antibodies in Chagas's disease. Trans R Soc Trop Med Hyg. 1982;76(3):334–340. doi: 10.1016/0035-9203(82)90184-5. [DOI] [PubMed] [Google Scholar]
- Krettli A. U., Pontes de Carvalho L. C. Binding of C3 fragments to the Trypanosoma cruzi surface in the absence of specific antibodies and without activation of the complement cascade. Clin Exp Immunol. 1985 Nov;62(2):270–277. [PMC free article] [PubMed] [Google Scholar]
- Krettli A. U., Weisz-Carrington P., Nussenzweig R. S. Membrane-bound antibodies to bloodstream Trypanosoma cruzi in mice: strain differences in susceptibility to complement-mediated lysis. Clin Exp Immunol. 1979 Sep;37(3):416–423. [PMC free article] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Luz Z. M., Coutinho M. G., Cançado J. R., Krettli A. U. Hemocultura: técnica sensível na detecço do Trypanosoma cruzi em pacientes chagásicos na fase crônica da doença de chagas. Rev Soc Bras Med Trop. 1994 Jul-Sep;27(3):143–148. doi: 10.1590/s0037-86821994000300004. [DOI] [PubMed] [Google Scholar]
- Martins M. S., Hudson L., Krettli A. U., Cançado J. R., Brener Z. Human and mouse sera recognize the same polypeptide associated with immunological resistance to Trypanosoma cruzi infection. Clin Exp Immunol. 1985 Aug;61(2):343–350. [PMC free article] [PubMed] [Google Scholar]
- Norris K. A., Bradt B., Cooper N. R., So M. Characterization of a Trypanosoma cruzi C3 binding protein with functional and genetic similarities to the human complement regulatory protein, decay-accelerating factor. J Immunol. 1991 Oct 1;147(7):2240–2247. [PubMed] [Google Scholar]
- Norris K. A., Galvão L. M., Schrimpf J. E., Cançado J. R., Krettli A. U. Humoral immune response to the Trypanosoma cruzi complement regulatory protein as an indicator of parasitologic clearance in human Chagas' disease. Infect Immun. 1994 Sep;62(9):4072–4074. doi: 10.1128/iai.62.9.4072-4074.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Norris K. A., Harth G., So M. Purification of a Trypanosoma cruzi membrane glycoprotein which elicits lytic antibodies. Infect Immun. 1989 Aug;57(8):2372–2377. doi: 10.1128/iai.57.8.2372-2377.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ouaissi A., Aguirre T., Plumas-Marty B., Piras M., Schöneck R., Gras-Masse H., Taibi A., Loyens M., Tartar A., Capron A. Cloning and sequencing of a 24-kDa Trypanosoma cruzi specific antigen released in association with membrane vesicles and defined by a monoclonal antibody. Biol Cell. 1992;75(1):11–17. doi: 10.1016/0248-4900(92)90119-l. [DOI] [PubMed] [Google Scholar]
- Smith D. B., Johnson K. S. Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene. 1988 Jul 15;67(1):31–40. doi: 10.1016/0378-1119(88)90005-4. [DOI] [PubMed] [Google Scholar]
- Taibi A., Plumas-Marty B., Guevara-Espinoza A., Schöneck R., Pessoa H., Loyens M., Piras R., Aguirre T., Gras-Masse H., Bossus M. Trypanosoma cruzi: immunity-induced in mice and rats by trypomastigote excretory-secretory antigens and identification of a peptide sequence containing a T cell epitope with protective activity. J Immunol. 1993 Sep 1;151(5):2676–2689. [PubMed] [Google Scholar]
- Towbin H., Staehelin T., Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. doi: 10.1073/pnas.76.9.4350. [DOI] [PMC free article] [PubMed] [Google Scholar]