CATHEPSIN D EXPRESSION IN HEMOCYTES AND ITS POTENTIAL ROLE IN THE IMMUNE SYSTEM OF DIPETALOGASTER MAXIMA (HEMIPTERA: REDUVIIDAE)

LEYRIA, J; CANAVOSO, LE; MOYETTA, NR; RAMOS FO

La Falda, Cordoba

Jornada; XXI Jornadas Científicas de la Sociedad de Biología de Córdoba; 2017

Sociedad de Biologia de Cordoba

Insects lack adaptive immunity and develop an efficient innate immune response against microorganisms and other aggressive agents. Insect immunity can be broadly divided in humoral and cellular, being the latter mediated by hemocytes. It has been recently reported that Jaburetox (JBTX), a recombinant peptide derived from a plant urease, induces an immunosuppressive effect in the triatomine Rhodnius prolixus, promoting the expression and activation of certain enzymes in the hemocytes. Although there is evidence associating cathepsin D (CatD), an aspartic peptidase, with the innate immune response, more studies are needed to establish its precise role. Moreover, the presence of CatD in insect hemocytes has not been reported yet. In this work, the expression of CatD in the hemocytes of Dipetalogaster maxima, a vector of Chagas´ disease, was evaluated in order to elucidate the potential targets of JBTX in the immune system. Hemocytes from nymphs of the fifth instar (6-8 days post-feeding) were used. Expression of CatD was analyzed by RT-PCR and Western blot. CatD exhibited a molecular weight compatible with a pro-peptidase. Immunofluorescence assays indicated that CatD was localized in the cytoplasm and nucleus of at least two populations of hemocytes. These results will allow us to understand the role of CatD in the immunity of insects and to expand our knowledge of the entomotoxic mechanisms displayed by plant ureases.