Article

Excretory-secretory products from Fasciola hepatica induce eosinophil apoptosis by a caspase-dependent mechanism.

Parasitología, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, CIBICI-CONICET, Medina Allende y Haya de la Torre, Ciudad Universitaria, 5000 Cordoba, Argentina.
Veterinary Immunology and Immunopathology (impact factor: 2.08). 07/2007; 117(3-4):197-208. DOI:10.1016/j.vetimm.2007.03.007 pp.197-208
Source: PubMed

ABSTRACT Eosinophils (Eo) are known to be important effector cells in the host defense against helminth parasites. Excretory-secretory products (ESP) released by helminths have shown wide immunomodulatory properties, such as the induction of cellular apoptosis. We investigated the ability of ESP from Fasciola hepatica to induce Eo apoptosis. In this work, we observed that ESP induced an early apoptosis of rat peritoneal eosinophils and that this phenomenon was time- and concentration-dependent. Furthermore, we demonstrated that activation of protein tyrosine kinases (TyrK) and caspases were necessary to mediate the Eo apoptosis induced by the ESP, and that carbohydrate components present in these antigens were involved in this effect. We have described for the first time the ability of ESP from F. hepatica to modify the viability of Eo by apoptosis induction. Besides that, we have observed Eo apoptosis in the liver of rats 21 days after F. hepatica infection. The diminution in Eo survival in early infection could be a parasite strategy in order to prevent a host immune response.

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Keywords

apoptosis induction
 
carbohydrate components present
 
effector cells
 
Eo apoptosis
 
Eo apoptosis induced
 
Eo survival
 
ESP induced
 
Excretory-secretory products
 
F. hepatica
 
F. hepatica infection
 
Fasciola hepatica
 
helminth parasites
 
host defense
 
host immune response
 
induce Eo apoptosis
 
parasite strategy
 
protein tyrosine kinases
 
rat peritoneal eosinophils
 
rats 21 days
 
wide immunomodulatory properties
 

Marianela C Serradell