Clonación de cDNAs que codifican para antígenos del parásito Toxocara canis
Resumen
Toxocariasis is a parasite infectious disease provoked by worm larvae from Toxocara species. Different nematodes are involved in the pathogenesis of the disease, being Toxocara canis the most frequently found. The disease is known as "Larva migrans syndrorne" and it may involve any human organ, and in sorne cases cause a serious condition. This parasite has a worldwide distribution, affecting mainly children. Since it is very difficult to isolate it (direct diagnosis), serologic techniques have been mostly used to detect the presence of the parasite in the organism, being ELISA the one preferred, using excreted and secreted antigens by the parasite larva. Besides being a troublesome technique, it has been widely documented that it has cross reactions with a wide variety of other parasites. Our main goal is to improve these serologic methods, we proposed to start cloning cDNA that codifies T. canis recombinant antigens. Methods. We started to trace a T. canis cDNA gene library, using infected patients ' serum. Results - Conclusions. After a very arduous work we have been able to clone 2 cDNA made of 1500 and 900 pair of bases that would codify a recombinant protein still not described.Palabras clave:
cDNA gene library, recombinant proteins, Toxocara canisReferencias
l. HERSKOVIC P, ASTORGA B. Toxocariasis humana en Chile. Rev Med Chile 1985; 113: 18-2 l.
DE SA VIGNY D, VOLLER A, WOODRUFF Y. Toxocariasis: serological diagnisis by enzyme inmunoassay. Journal of Clinical Pathology 1979; 32: 284-288.
MAGNA VAL J, MICHAULT A, CALON N, CHARLET J. Epidemiology of human toxocariasis in La Réunion. Trans Roy Soc Trop Med Hyg 1994; 88: 531-533.
HERSKOVIC P, LEIV A S, ASTORGA B, MARZOUKA E, CEPEDA V. Toxocariasis humana en Chile. Evaluación del diagnóstico serológico mediante ELISA. Parasitol al Día 1986: 1 O: 76-80.
JACQUIER P, GOTTSTEIN B, STINGELIN Y, ECKERT J. Immunodiagnosis of toxocariasis in humans: Evaluation of a new enzyme-linked immunosorbent assay kit. J Clinic Microbiology 1991; 29: 1831-1835.
NUNES C, TUNDISI R, GARCÍA J, HEINEMANN M, OGASSA W ARA S, RICHTZENHAIN J. Cross-reaction between Toxicara Canis and Ascaris summ in the diagnosis of visceral larva migrans by western blotting technique, Rev Inst Med Trop S. Paulo 1997; 39: 253-256.
KENNEDY M, MAIZELS R. MEGHJI M, YOUNG L, QURESHI F, SMITH H. Species-specific and common epitopes on the secreted and surface antigens of Toxocara cati and Toxocara canis infective larvae. Parasite Immonol 1987; 9: 407-420.
PAGE A, RICHARDS T, LEWIS J, OMAR H, MAIZELS R. Comparison of islates and species of Toxocara and Toxocaris by biosynthetic labelling of somatic and ES protein from infective larvae. Parasitology 1991; 3: 451-464.
KONOSHI E. Monoclonal antibodies miltireactive with parasite antigens prodiced by hybridomas generated from naive mice. Parasitology 1997; 115: 387-393.
IGLESIAS R, LEIRO J, UBEIRA F, SANT AMARIA M, NA V ARRETE I, SAN MARTIN M. Antigens cross-reacti vity in mice between third-stage larvae of anisakis simplex ahd other nematodes. Parasitol Res 1996; 82: 378-381.
FREYER B, ESCHENBACHER K, MEHLHORN H, RUEGER W. Isolation and characterization of cDNA clones encoding a 32-kDa dense-granule antigen of Sarcocystis muris (apicornplexa). Parasitol Res 1998; 84: 583-589.
SAMBROOK J, FRITSCH E, MANIATIS T. Molecular cloning a laboratory manual. Second Edition. Cold Spring Harbor Laboratory Press, 1989.
LAGERKVIST A, STEW ART J, LAGERSTROM-FERMER M, LANDEGREN U. Manifold sequencing: Efficient processing of large sets of sequencing reactions. Proc Natl Acad Sci USA 1994; 91: 2245-2249.
HARLOW E, LANE D. Antibodies: A laboratory Manual. Cold Spring Harbor Laboratory, 1988.
GEMS D, FERGUSON C, ROBERTSON B. NIEVES R, PAGE A, BLAXTER M, ET AL. An abundant, trans-spliced mRNA from Toxocara canis infective larvae encodes a 26- kDa pro te in with homology tophosphatidyllcthanolamine-binding proteins. J Biol Chem 1995; 270: 18517-18522.
LOUKAS A. SELZER P, MAIZAELS R. Characrerization of Tc-cp 1-1, a capthepsin Llike cysteine protease frorn Toxocara canis infective larvae. Mol Biochem Parasitol 1998; 92: 275-289.
YAHIRO S. CAIN G, BUTLER J. Identification characterization and expression of a Toxocara canis nematode polyprotein allergen TBA-1. Parasite Immunol 1998; 20: 351-357.
LOUKAS A, HUNT P, MAIZELS R. Cloning and expression of an aquaporin-like gene from a parasitic nematode. Mol Biochern Parasitol 1999; 99: 287-293.
