Immunoblot Analysis of Trypomastigote Excreted–Secreted Antigens as a Tool for the Characterization of Trypanosoma cruzi Strains and Isolates

Abstract

An analysis of antibody recognition of Trypanosoma cruzi exoantigens by immunoblotting revealed a unique banding pattern that seems to be characteristic of each strain or isolate. Trypomastigote excreted-secreted antigens (TESA) present in supernatants of LLC-MK2 cells infected with 5 strains and 10 isolates of T. cruzi produced 13 different immunoblotting patterns. The same bands were observed when probed with acute-phase Chagas' disease serum or with serum from a rabbit immunized with the repetitive domain of T. cruzi transialidase recombinant protein (anti-shed acute-phase antigens). Three similar patterns were observed with TESA from 3 human isolates that probably belong to the same T. cruzi strain. When clone CL Brener, clone CL-14, and CL parental strain were analyzed, the same bands were observed, although they presented different biological behavior. These results suggest that immunoblotting analysis of TESA may be a useful tool for characterization of T. cruzi strains and isolates.

Excretory-Secretory Antigens of Trypanosoma cruzi Are Potentially Useful for Serodiagnosis of Chronic Chagas' Disease

“…The discrimination of different clinical forms of the disease was not possible based upon the analysis of the antigenic profiles. The data reported herein confirm previous studies (10,11,20,21) and show that the high sensitivity of TESA-blot in chronic cases in combination with the absence of cross-reactions with leishmaniasis makes this test attractive as an alternative to conventional tests. On the other hand, it may be used as a specific confirmatory assay to exclude cross-reactions after serum screening by conventional serology (20).…”

“…The 150-to 170-kDa band identified herein probably corresponds to the 150-to 160-kDa band described previously (11,20). In agreement with other studies (10,11,20,21), the recognition of the 150-to 170-kDa band in different strains provides indirect evidence that this molecule is not very polymorphic among T. cruzi isolates and contains conserved epitopes that are highly immunogenic in the chronic phase of Chagas' disease. Thus, this antigenic preparation (TESA) meets the criteria proposed by Zingales et al (24) and Stolf (18).…”

“…On the other hand, it may be used as a specific confirmatory assay to exclude cross-reactions after serum screening by conventional serology (20). An additional, favorable feature of TESA is its stability when stored either at Ϫ40 or 4°C, resulting in similar immunoblot antigenic patterns (11). The 150-to 170-kDa band identified herein probably corresponds to the 150-to 160-kDa band described previously (11,20).…”

“…An additional, favorable feature of TESA is its stability when stored either at Ϫ40 or 4°C, resulting in similar immunoblot antigenic patterns (11). The 150-to 170-kDa band identified herein probably corresponds to the 150-to 160-kDa band described previously (11,20). In agreement with other studies (10,11,20,21), the recognition of the 150-to 170-kDa band in different strains provides indirect evidence that this molecule is not very polymorphic among T. cruzi isolates and contains conserved epitopes that are highly immunogenic in the chronic phase of Chagas' disease.…”

Purified Excreted-Secreted Antigens from Trypanosoma cruzi Trypomastigotes as Tools for Diagnosis of Chagas' Disease

“…The use of TESA proteins for the diagnosis of Chagas' disease has been reported, and their use has generally provided good results in terms of specificity and sensitivity (15,18,20,27,28). However, most studies have tested relatively small numbers of samples (18,20,28), and some have used TESA proteins from a single strain (27,28).…”