ABSTRACT
La enfermedad de Chagas, causada por el parásito protozoarioTrypanosoma cruzi, es endémica en América Central y Sudaméricay representa la miocarditis más frecuente a nivel mundial.El establecimiento de la infección crónica conduce a una patologíacardíaca debilitante por la cual mueren más de 50,000 personascada año. No existe consenso sobre si la causa del daño tisulares ocasionada por el parásito o está exacerbada por una respuestaautoinmune. En ambos escenarios, ha sido sugerido quecruzipaína- la principal cisteín proteasa del T. cruzi- cumple unrol importante en la progresión de la enfermedad.Cruzipaína, miembro de la superfamilia de las papaínas, seexpresa como una mezcla compleja de isoformas en los diferentesestadíos de desarrollo de todas las cepas del parásito. Esta glicoproteínaparticipa en la internalización del T. cruzi en las célulasmamíferas, lo que ha sido demostrado con inhibidores específicosde la enzima que interfieren en la invasión celular y la replicacióndel parásito. Además, cruzipaína genera una fuerte respuestaimmune en individuos infectados. Estas característicashacen de cruzipaína un potencial blanco de drogas terapéuticas.La presente revisión resume el conocimiento actual sobre elrol de cruzipaína en la patogénesis de la enfermedad, su compromisoen la invasión de células del huésped así como su participaciónen la activación y evasión de la respuesta inmune enmodelos experimentales y en pacientes chagásicos. El avance enesta área de investigación, proveerá nuevas estrategias terapéuticastendientes a incrementar la respuesta inmunoprotectiva yprevenir la respuesta deletérea producida por el parásito
The protozoan parasite Trypanosoma cruzi, etiological agentof Chagas disease, is endemic in Central and South America andproduces the most common myocarditis worldwide.Parasite persistence eventually leads to a debilitating heartdisease that kills more than 50,000 people every year. There is noconsensus as to whether tissue damage is caused entirely by theparasite or is exacerbated by an autoimmune response. In bothmodels of disease progression, cruzipain- the major cysteine proteinaseof T. cruzi- has been suggested to play an important role.Cruzipain is a member of the papain superfamily, and it isexpressed as a complex mixture of isoforms by different strains ofthe parasite, as well as in all its developmental stages. This parasiteglycoprotein plays a role in the process of T. cruzi internalizationinto mammalian cells, as proved by specific enzyme inhibitors, whichinterfere with cell invasion and inhibit parasite replication.In addition, cruzipain not only is essential for parasite survivalbut also generates a strong immune response in infected individuals.These characteristics point to cruzipain as a potential targetfor drug therapy and for the generation of immune responses.This review analyses our present knowledge of the role ofcruzipain in the disease pathogenesis, its involvement in host cellinvasion, immune activation and evasion by T. cruzi in experimentalmodels and human infection. Ongoing studies in this researcharea may provide novel therapeutic strategies that couldenhance the immunoprotective response while preventing thedeleterious parasite elicited responses observed during Chagasdisease
Subject(s)
Humans , Cysteine Endopeptidases/immunology , Trypanosoma cruzi/immunology , Host-Parasite Interactions/immunology , Chagas Disease/immunology , Trypanosoma cruzi/enzymology , Chagas Disease/etiology , Chagas Disease/parasitology , Autoimmunity/immunology , Cardiomyopathies/etiology , Cardiomyopathies/parasitologyABSTRACT
Alpha-galactosidase (alpha-Gal) enzyme, which is encoded by the melA gene hydrolyzes alpha-1,6 galactoside linkages found in sugars, such as raffinose and stachyose. These alpha-galacto-oligosaccharides (alpha-GOS), which are found in large quantities in vegetables, such as soy, can cause gastrointestinal disorders in sensitive individuals because monogastric animals (including humans) do not posses alpha-Gal in the gut. The use of microbial alpha-Gal is a promising alternative to eliminate alpha-GOS in soy-derived products. Using degenerate primers, the melA gene from Lactobacillus (L.) fermentum CRL722 was identified. The complete genomic sequence of melA (2223 bp), and of the genes flanking melA, were obtained using a combination of polymerase chain reaction-based techniques, and showed strong similarities with the alpha-Gal gene of thermophilic microorganisms. The alpha-Gal gene from L. fermentum CRL722 was cloned and the protein purified from cell-free extracts of the native and recombinant strains using various techniques (ion exchange chromatography, salt precipitation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and ultra-filtration); Its main biochemical properties were determined. The enzyme was active at moderately high temperatures (55 degrees C) and stable at wide ranges of temperatures and pH. The thermostable alpha-Gal from L. fermentum CRL722 could thus be used for technological applications, such as the removal of alpha-GOS found in soy products. The complete melA gene could also be inserted in other micro-organisms, that can survive in the harsh conditions of the gut to degrade alpha-GOS in situ. Both strategies would improve the overall acceptability of soy-derived products by improving their nutritional value.
