All Trypanosoma cruzi developmental forms present lysosome-related organelles

• Published in: Histochemistry and cell biology 2008-12, Vol.130 (6), p.1187-1198
• Main Authors: Sant’Anna, Celso, Parussini, Fabiola, Lourenço, Daniela, de Souza, Wanderley, Cazzulo, Juan Jose, Cunha-e-Silva, Narcisa Leal
• Format: Article
• Language: English
• Subjects: Animals; Biochemistry; Biomedical and Life Sciences; Biomedicine; Carboxypeptidases - analysis; Cell Biology; Cellular biology; Cysteine Endopeptidases - analysis; Developmental Biology; Enzymes; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Life Cycle Stages; Lysosomes - enzymology; Lysosomes - ultrastructure; Microscopy, Electron, Transmission; Molecules; Organelles - enzymology; Organelles - ultrastructure; Original Paper; Parasites; Proton-Translocating ATPases - analysis; Protozoan Proteins - analysis; Trypanosoma cruzi; Trypanosoma cruzi - enzymology; Trypanosoma cruzi - growth & development; Trypanosoma cruzi - ultrastructure
• ISSN: 0948-6143; 1432-119X
• DOI: 10.1007/s00418-008-0486-8

Trypanosoma cruzi epimastigote forms concentrate their major protease, cruzipain, in the same compartment where these parasites store macromolecules obtained from medium and for this ability these organelles were named as reservosomes. Intracellular digestion occurs mainly inside reservosomes and seems to be modulated by cruzipain and its natural inhibitor chagasin that also concentrates in reservosomes. T . cruzi mammalian forms, trypomastigotes and amastigotes, are unable to capture macromolecules by endocytosis, but also express cruzipain and chagasin, whose role in infectivity has been described. In this paper, we demonstrate that trypomastigotes and amastigotes also concentrate cruzipain, chagasin as well as serine carboxypeptidase in hydrolase-rich compartments of acidic nature. The presence of P-type proton ATPase indicates that this compartment is acidified by the same enzyme as epimastigote endocytic compartments. Electron microscopy analyzes showed that these organelles are placed at the posterior region of the parasite body, are single membrane bound and possess an electron-dense matrix with electronlucent inclusions. Three-dimensional reconstruction showed that these compartments have different size and shape in trypomastigotes and amastigotes. Based on these evidences, we suggest that all T. cruzi developmental stages present lysosome-related organelles that in epimastigotes have the additional and unique ability of storing cargo.