Detection of antibodies in sera from Chagas' disease patients using a Trypanosoma cruzi immunodominant recombinant antigen

Abstract

A Trypanosoma cruzi DNA fragment encoding an immunodominant repetitive antigen (H49) was subcloned into a protein purification and expressed system. Purified H49 peptide reacted specifically in an enzyme-linked immunosorbent assay (ELISA) with sera from T. cruzi-infected patients, but not with sera from patients with other parasitic diseases such as leishmaniasis and T. rangeli-infection. The H49 recombinant ELISA was able to detect specific antibodies in 84% of chronic chagasic serum samples tested. One of the major advantage of the recombinant ELISA for serodiagnosis of chronic Chagas' disease resides in its high specificity (100%). Our data suggest that recombinant peptides could provide a practical basis for specific diagnosis tests for Chagas' disease.

The Repetitive Cytoskeletal Protein H49 of Trypanosoma cruzi Is a Calpain-Like Protein Located at the Flagellum Attachment Zone

“…The 204-bp repeat of the H49 gene was cloned in a pGEX vector (GE Healthcare) as described previously [32]. The catalytic domain (CysPc) and the H49 degenerated repeats (H49 deg) were amplified by PCR with specific primers based on the H49/calpains XM_799896 and XM_804900, respectively (Table S2).…”

An improved serodiagnostic test for Chagas' disease employing a mixture of Trypanosoma cruzi recombinant antigens

“…Evaluation of some recombinant proteins has shown promising results for diagnosis of T. cruzi infection. [11][12][13][14][15][16][17][18][19][20][21][22][23] Recently, our group evaluated the diagnostic efficiency of six T. cruzi recombinant antigens (H49, JL7, JL8, A13, B13, and 1F8) by ELISA with a panel of 541 serum samples of chagasic and nonchagasic individuals from nine countries in South and Central America. 19 The performance of each recombinant protein was compared with an in-house ELISA made with an alkaline extract of T. cruzi epimastigotes (EAE-ELISA).…”

A recombinant peptide antigen line immunoassay optimized for the confirmation of Chagas' disease

“…Most of the tests that are commercially available today in Brazil employ crude parasite extracts or subcellular fractions as antigen preparations. In recent years, various investigators have characterized T. cruzi ‐specific immunoreactive antigens, and several studies have evaluated the diagnostic potential of these antigens either in the form of recombinant proteins or as synthetic peptides 6–19 . General conclusions that can be drawn from the published results are that 1) recombinant antigens are more specific than parasite extracts, which can cross‐react with sera from patients harboring other diseases such as leishmaniasis, Trypanosoma rangeli infection, syphilis, or rheumatic fever; 2) sensitivities reported for the different recombinant antigens vary with the clinical status of the patient and the manifestation of the disease; and 3) the combined use of various recombinant antigens in the same test improves diagnostic sensitivity.…”