title: Echinococcus multilocularis laminated-layer components and the E14t 14-3-3 recombinant protein decrease NO production by activated rat macrophages in vitro.
abstract: Echinococcus multilocularis and Echinococcus granulosus cause alveolar and cystic (unilocular) echinococcosis, respectively, in humans and animals. It is known that these parasites can affect, among other molecules, nitric oxide (NO) production by periparasitic host cells. Nevertheless, detailed dissection of parasite components specifically affecting cell NO production has not been done to date. We compare the effect of E. granulosus and E. multilocularis defined metacestode structural (laminated-layer associated) and metabolic (14-3-3 protein, potentially related with E. multilocularis metacestode tumor-like growth) components on the NO production by rat alveolar macrophages in vitro. Our results showed that none of these antigens could stimulate macrophage NO production in vitro. However, a reversed effect of some Echinococcus antigens on NO in vitro production was found when cells were previously exposed to LPS stimulation. This inhibitory effect was found when E. multilocularis laminated-layer (LL) or cyst wall (CW) soluble components from both species were used. Pre-stimulation of cells with LPS also resulted in a strong, dose-dependent reduction of NO and iNOS mRNA production after incubation of cells with the E14t protein. Thus, the E. multilocularis 14-3-3 protein appears to be one of the components accounting for the suppressive effect of the CW and LL metacestode extracts.
authors.affiliation: Laboratorio de Parasitología, Facultad de Farmacia, Universidad de Salamanca, Avda, Campo Charro s/n 37007 Salamanca, España, Spain.
authors.forename: M Amparo
authors.initials: MA
authors.lastname: Andrade
authors.forename: Mar
authors.initials: M
authors.lastname: Siles-Lucas
authors.forename: Elsa
authors.initials: E
authors.lastname: Espinoza
authors.forename: José Luis
authors.initials: JL
authors.lastname: Pérez Arellano
authors.forename: Bruno
authors.initials: B
authors.lastname: Gottstein
authors.forename: Antonio
authors.initials: A
authors.lastname: Muro
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000494:pharmacology*; D000818:Animals; D048209:Echinococcus granulosus / Q000502:physiology; D048210:Echinococcus multilocularis / Q000276:immunology / Q000502:physiology*; D015801:Helminth Proteins / Q000032:analysis / Q000235:genetics / Q000494:pharmacology*; D006801:Humans; D016676:Macrophages, Alveolar / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000494:pharmacology
chemical_list: D048948:14-3-3 Proteins; D015801:Helminth Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D009569:Nitric Oxide; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat