CONICET | Buscador de Institutos y Recursos Humanos

The development of resistance to insecticides and the need to use more rational and environment-friendly strategies have driven the research for new compounds of natural origin with entomotoxic properties. In this context, it has been reported that Jaburetox (Jbtx), a recombinant peptide generated from a urease of the leguminous Canavalia ensiformis, is toxic and lethal for insect species of several orders;the mechanism of action is little understood, thus limiting its biotechnological application. In this work, we studied the effect of Jbtx on the immune response of Rhodnius prolixus, an insect vector of Chagas? disease widely used as a model for physiological, genetic and biochemical research. The findings demonstrated that Jbtx triggers a humoral and cellular immune response, inducing hemocyte aggregation, apoptosis and increasing the activity of phenoloxidase, a key enzyme in melanization and defense processes. Jbtx also affected the nitric oxide synthase pathway, involved in immunity and signaling, modulating the mRNA and protein expression of the enzyme as well as its enzymatic activity and the production of nitric oxide. Finally, the Jbtx-induced activation of the immune response did not protect the insects against subsequent infections by entomopathogenic bacteria, suggesting an immunosuppressive effect caused by the peptide.