Partial protective responses induced by a recombinant cysteine proteinase from Leishmania (Leishmania) amazonensis in a murine model of cutaneous leishmaniasis

Abstract A 500 bp fragment encoding an isoform of cysteine proteinase from Leishmania ( Leishmania ) amazonensis was subcloned and expressed in the pHis vector, resulting in a recombinant protein of 24 kDa, rLacys24. In Western blots of L. ( L. ) amazonensis extracts, antibodies directed to rLacys24 recognized a cysteine proteinase isoform of 30 kDa. Analysis by fluorescence-activated cell sorter showed a significantly higher expression of CD8 + lymphocytes in animals immunized with rLacys24 plus CFA, whereas a low expression of CD4 + lymphocytes was observed in these animals. The cytotoxicity of lymphocytes isolated from mice immunized with rLacys24 plus CFA on L. ( L. ) amazonensis -infected macrophages was significantly higher than that observed in the presence of lymphocytes from control animals. Immunization of BALB/c mice with rLacys24 plus CFA resulted in a low but significant decrease of foot lesions after challenge with L. ( L. ) amazonensis compared to those exhibited by control mice.