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The data presented here is related to negative results obtained with the recombinant expression of chitinase from four species of Leishmania parasites in two expression systems, performed in order to investigate the molecular characteristics of the Leishmania chitinase and its possible application in leishmaniasis diagnosis. Thus, heterologous Leishmania sp chitinase proteins were expressed in bacteria using the prokaryotic expression vector pET28a and Escherichia coli Mach-T1, and in Spodoptera frugiperda (Sf9) insect cells, using the eukaryotic bac-to-bac expression system (Thermo Fisher Scientific) to produce recombinant baculoviruses to infect Sf9. Biochemical and cellular analysis of the various recombinant forms of the Leishmania sp chitinase produced in prokaryotic and eukaryotic expression systems were performed through SDS-PAGE and Western blotting. Chitinase produced and purified from bacteria presented low yield and formed inactive aggregates. Heterologous chitinase obtained after infection of Sf9 insect cells with all the four Leishmania species recombinant baculoviruses presented high yield of insoluble proteins. Dot-blot serological tests presented inconclusive results against the recombinant Leishmania sp chitinases produced in both expression systems. The experiments described in this paper can help researchers to avoid errors when choosing a recombinant expression systems to produce Leishmania parasites proteins for biotechnological purposes.

Leishmaniasis, an infectious disease that affects humans, domestic dogs, and wild animals, is caused by 20 of the 53 Leishmania genus species and is transmitted by sandflies. Despite its significant impact, the disease is often neglected. Leishmania genus, belong to Trypanosomatide Family and Kinetoplastida Order, are grouped in five subgroups according to biogeographic and evolution history of parasites and hosts. The GH18 Leishmania chitinase is encoded by a specie-specific single copy gene, conserved in basal groups of trypanosomatids, and is absent in the genus Trypanosoma. Preservation of the chitinase genomic locus in the aquatic free-living protozoan Bodo saltans, discloses a primitive common origin. Trypanosomatid chitinase amino acid sequence comparative analysis revealed high similarity with chitinase from sea living prokaryotes and protozoan microorganisms, indicating a probable marine origin. Amino acid sequence comparative analysis revealed that perhaps the trypanosomatid chitinase derived from a water living Kinetoplastida ancestor and its phylogenetic reconstruction corroborates the Supercontinent Origins theory for Leishmania. The chitinase-encoding gene was effective for differential molecular diagnosis among Leishmania clinical important species worldwide.

Enzymes called proteases play important roles in the physiology of all living organisms and in the interaction of a parasite/symbiont with its host. Different types of peptidases act on specific substrates and are regulated by specific inhibitors. Ecotins, described firstly in Eschericchia coli, are inhibitors of serine peptidases (ISP) from S1A family including trypsin, chymotrypsin, neutrophil elastase, and cathepsin G. Ecotin-like inhibitors are present in parasites from Trypanosomatidae family, including Trypanosoma cruzi, the causative agent of Chagas’ disease. This chapter explores the evolutive origin of the T. cruzi TcISP2 and its possible interactions with proteins of the human immune system and in Chagas’ disease. The phylogenetic relationship of TcISP2 with trypanosomatids ISPs, comparative loci analysis among trypanosomatids, and the occurrence of bacteria endosymbionts in the group strongly suggest horizontal transfer as the main origin mechanism for trypanosomatids ISPs, followed by duplication events and losses that could explain its current genomic pattern. The relationship of TcISP2 with the vertebrate host immune system can be inferred by its antigenicity in Chaga’s disease murine model, presenting high antibody titer after 60 days post-infection, which could indicate the inhibition of TcISP2 activity associated with chronic phase of the Chaga’s disease.