Comparison of the Peptidase Activity in the Oncosphere Excretory/Secretory Products of Taenia Solium and Taenia Saginata

Abstract

We compared the peptidase activities of the excretory/secretory (E/S) antigens of oncospheres of Taenia solium and related, but nonpathogenic, Taenia saginata. Taenia solium and T. saginata oncospheres were cultured, and the spent media of 24-, 48-, 72-, and 96-hr fractions were analyzed. Activities for serine peptidases (chymotrypsin-, trypsin-, and elastase-like), cysteine peptidases (cathepsin B-, cathepsin L-, and calpaine-like), and aminopeptidase (B-like peptidases) were tested fluorometrically with peptides coupled to 7-amino-4-methylcoumarin. In both species, the E/S antigens showed cysteine, serine, and aminopeptidase activities. Although no particular peptidase had high activity in T. solium, and was absent in T. saginata, or vice versa, different patterns of activity were found. A chymotrypsin-like peptidase showed the highest activity in both parasites, and it had 10 times higher activity in T. solium than in T. saginata. Trypsin-like and cathepsin B-like activities were significantly higher in T. solium. Minimal levels of cathepsin B were present in both species, and higher levels of elastase-like and cathepsin L-like activity were observed in T. saginata. Taenia solium and T. saginata have different levels and temporal activities of proteolytic enzymes that could play a modulator role in the host specificity for larval invasion through penetration of the intestinal mucosa.

Adsorption and inactivation of proteolytic enzymes by Triaenophorus nodulosus (Cestoda)

“…This agrees with the data obtained by other authors showing the production of serine proteinase inhibitors by cestodes (Pappas, 1978;Pappas & Uglem, 1990). Serine proteinase inhibitors are among the key components of secretory products in many parasite species (Zimic et al, 2007). They play an important role in the parasite's survival because of their ability to inhibit the host's enzymes, and are normally present in the microenvironment and/or secreted by the immune effector cells (Zang & Maizels, 2001).…”

Gene cloning, expression, and localization of antigen 5 in the life cycle of Echinococcus granulosus

“…However, up to date, whether Ag5 is expressed in the two infective stages-protoscolex and egg is still unknown. EgAg5 has significant homology with the Trypsin-like protein of Taenia solium which exists in the excretory/secretory (E/S) antigens of oncosphere of T. solium and shows high level of activity in serine proteases (Zimic et al 2007); therefore, we guess EgAg5 is also expressed in oncosphere or egg of E. granulosus.…”

Cisteínoproteasas catepsinas L de Taenia solium: rol biológico en la infección y potencial uso para el inmunodiagnóstico de la neurocisticercosis

“…El cerdo es infectado al consumir alimentos contaminados con huevos, o proglótidos grávidos de la tenia adulta. Después que el cerdo ha ingerido los huevos, estos son estimulados por el ambiente ácido del estómago lo cual provoca que se liberen los embriones u oncósferas, estos luego atraviesan la pared intestinal y migran a diferentes partes del cuerpo por el torrente sanguíneo (5) . En el tejido muscular esquelético o nervioso del cerdo, las oncósferas suelen anclarse hasta convertirse en cisticercos, produciéndose la cisticercosis porcina.…”

“…Del mismo modo, las que presentaban actividad de tripsina y catepsina B también fueron mayores en T. solium; mientras que las proteínas con actividad similar a catepsina L y elastasa resultaron más altas en T. saginata. Las diferencias entre los perfiles de actividad de las peptidasas entre ambos parásitos, explicarían el rol modulador de las enzimas proteolíticas en la especificidad del hospedero para la invasión del cisticerco mediante la penetración de la mucosa intestinal, hipótesis que aún falta verificarse (5) .…”