Antigenic significance of a Trypanosoma rangeli sialidase.
The Trypanosoma rangeli-secreted sialidase was purified by bovine submaxillary gland mucin-sepharose affinity chromatography. In immunoblotting analysis, antibodies raised against this molecule recognized polypeptides of 73 kDa in T. rangeli medium supernatant (TrSialr) and of 70 kDa in the cell lysates of T. rangeli (TrSials) and T. cruzi (TcSialL) epimastigotes. TrSialr, TrSials, and TcSialL were subjected to proteolytic cleavage with papain; the resultant peptide pattern displayed differences in the immunoblotting profiles. TrSials was purified by immunoprecipitation, and this protein band was recognized by sera from T. cruzi-infected chronic mice and Chagas' disease patients. In contrast, TrSialr was not recognized by these sera. The antibodies from the infected mice also recognized a band of 70 kDa present in the medium. These preliminary observations imply that the released and somatic sialidases are partially different molecules, with probably different biological roles. The related proteins recognized in T. rangeli and T. cruzi epimastigotes share many antigenic characteristics but have some structural differences, probably related to their function in the parasitic cell. On the basis of the strong antigenicity of TrSials, this molecule is proposed as the antigen for the detection of antibodies arising during T. cruzi infection.
Center for Research and Diagnosis of Parasitic Diseases (CIDEP), Faculty of Medicine, University of Panama, Panama.
Azael
A
Saldaña
Robert A
RA
Harris
Anders
A
Orn
Carlota
C
Monroy
Eduardo
E
Ortega-Barria
Octavio E
OE
Sousa
D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis; D000953:Antigens, Protozoan / Q000032:analysis / Q000276:immunology*; D015153:Blotting, Western; D014355:Chagas Disease / Q000276:immunology; D002847:Chromatography, Agarose; D003429:Cross Reactions; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D051379:Mice; D009439:Neuraminidase / Q000276:immunology / Q000378:metabolism*; D010206:Papain; D015800:Protozoan Proteins / Q000032:analysis / Q000276:immunology*; D014345:Trypanosoma / Q000201:enzymology* / Q000276:immunology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007106:Immune Sera; D015800:Protozoan Proteins; D009439:Neuraminidase; D010206:Papain