CONICET | Buscador de Institutos y Recursos Humanos

The Arginine Kinase from Trypanosoma cruzi (TcAK) is thoughtto be the product of gene transfer from an invertebrate host to aTrypanosoma ancestor. The function of this enzyme in the parasiteis still unknown, but since it was found in extra-cellular T. cruzi vesicles,and it shares a very conserved sequence with invertebrateAKs, which are well known allergens in a very wide range of species,we suspect that TcAK might have some immune modulating actionby making immune response incline towards a Th2 response that isineffective against the parasite, instead of a Th1 response that couldcontrol the infection.To start testing this hypothesis we decided to measure the presenceof TcAK specific IgE antibodies in the serum of individualsinfected and non-infected with the parasite. Samples were takenfrom individuals in Venezuela (49 Chagas positive and 46 Chagasnegative) and in Argentina (20 positive and 10 negative), in order totake into account the regional differences in parasite strains and inhost immune response. Detection was carried on by ELISA againstrecombinant TcAK, using secondary anti-human IgE coupled withalkaline phosphatase and pNPP dephosphorilation. Results for eachregional sera origin were obtained and treated separately, using forboth groups a ROC curve and Mann-Withney test.With both regional origins of the sera we found statistical significantdifferences in the TcAK recognition between the non-infectedand infected sera, with an Area Under the ROC curve >0,75 anda p < 0,005 for both the ROC analysis and the Mann-Withney test.These results points out that infection with the parasite trigers theproduction of IgE antibodies against TcAK, but wether this primingof the response towards IgE secretion is relevant for the infection isstill to be determined.