title: Effect of Cysticercus cellulosae on neutrophil function and death.
abstract: Neutrophils, eosinophils and macrophages interact with invading parasites and naive hosts. The initial reaction of leukocytes is the generation of reactive oxygen species (ROS). The cytotoxic effects of extracts derived from intact Cysticercus cellulosae and from the scolex or membrane fractions on neutrophils were examined. DNA fragmentation of neutrophils was observed when cells were incubated with an extract from the intact metacestode; however, the addition of antioxidant enzymes to the incubation medium had a protective effect. The scolex and membrane extracts did not affect DNA fragmentation of neutrophils. Hydrogen peroxide production of neutrophils incubated with metacestode fractions from C. cellulosae increased by 190% (total extract), 120% (scolex) or 44% (membrane). An increase in antioxidant catalase activity (28%) concomitant with the increased production of ROS was observed in neutrophils incubated with metacestode fractions, which could be an attempt at self-protection. ROS production by neutrophils in the presence of the intact cysticerci extract did not alter phagocytosis. In contrast, the scolex and membrane fractions increased the phagocytic capacity of neutrophils by 44 and 28%, respectively. The results showed that the extract from intact C. cellulosae was toxic for neutrophils via ROS production, leading to DNA fragmentation and inhibition of phagocytic capacity, but neutrophils are able to protect themselves against oxidative stress by via catalase activity.
authors.affiliation: Department of Basic Science, Faculty of Zootechny and Food Engineering, University of São Paulo, Av. Duque de Caxias Norte 225, 13635-000 Pirassununga, SP, Brazil.
authors.forename: L M
authors.initials: LM
authors.lastname: Chaible
authors.forename: T C
authors.initials: TC
authors.lastname: Alba-Loureiro
authors.forename: A A M
authors.initials: AA
authors.lastname: Maia
authors.forename: S M P
authors.initials: SM
authors.lastname: Pugine
authors.forename: C R
authors.initials: CR
authors.lastname: Valle
authors.forename: T C
authors.initials: TC
authors.lastname: Pithon-Curi
authors.forename: R
authors.initials: R
authors.lastname: Curi
authors.forename: M P
authors.initials: MP
authors.lastname: De Melo
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D002478:Cells, Cultured; D003551:Cysticercosis / Q000469:parasitology / Q000662:veterinary; D003552:Cysticercus / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D053938:DNA Fragmentation; D018509:DNA, Helminth / Q000276:immunology*; D005434:Flow Cytometry / Q000662:veterinary; D005979:Glutathione Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000201:enzymology / Q000469:parasitology* / Q000502:physiology*; D018384:Oxidative Stress; D010587:Phagocytosis; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D013552:Swine; D013553:Swine Diseases / Q000469:parasitology
chemical_list: D018509:DNA, Helminth; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase