title: Prostaglandins E2and D2-regulators of host immunity in the model parasite Diphyllobothrium dendriticum: An immunocytochemical and biochemical study.
abstract: The spectrum of immunomodulating molecules produced by tapeworms is not yet well understood. The aims of this study, on the tapeworm Diphyllobothrium dendriticum, were: 1) detection and quantification of prostaglandins (PGs) E2and D2by high performance liquid chromatography; 2) visualization of PGE2and PGD2in specific cells, using methods of immunocytochemistry and confocal laser scanning microscopy; and 3) investigation of the ultrastructure of the cells potentially producing PGE2and PGD2. The PGE2immunoreaction (IR) was found in the apical terminals of the frontal glands and sensory organs in the tegument and in small neurons belonging to the main cords and commissures. PGE2-IR partly coincided with α-tubulin-IR. PGD2-IR occurred in the muscle fibers of longitudinal and transverse body muscles and coincided with phalloidin TRITC staining. Both PGE2and PGD2were found in the flame cells of the excretory system. Ultrastructural study of the tegument revealed two types of structures that potentially produce PGE2: ciliated and unciliated free nerve endings and frontal gland terminals reinforced with neurotubules. In the main nerve cords, small neurons were identified as potentially exhibiting PGE2-immunoreactivity. In homogenates of the plerocercoids, the measured content of PGE2and PGD2was 33.15ngmg-1and 1.94ngmg-1of fresh tissue weight, respectively. We found evidence of PGE2and PGD2in D. dendriticum parasitizing Coregonus autumnalis (fish) and proved excretion of PGE2and PGD2in response to C. autumnalis blood serum. Prostaglandins produced by D. dendriticum probably play a dual role: 1) PGE2and PGD2potentially modulate the fish antiparasitic immune response; 2) PGE2is presumably necessary for proper development and function of the nervous system, and PGD2can act as an antagonist against mediators causing muscle contraction.
authors.affiliation: Institute of General and Experimental Biology, Siberian Branch of Russian Academy of Sciences, Sakhyanovoi st. 6, 670047 Ulan-Ude, Russia. Electronic address: kutyrevi@yahoo.com.
authors.forename: Ivan A
authors.initials: IA
authors.lastname: Kutyrev
authors.affiliation: Department of Invertebrate Zoology, Faculty of Biology, M.V. Lomonosov Moscow State University, 1/12, Leninskie Gory, 119234 Moscow, Russia.
authors.forename: Natalia M
authors.initials: NM
authors.lastname: Biserova
authors.affiliation: Institute of General and Experimental Biology, Siberian Branch of Russian Academy of Sciences, Sakhyanovoi st. 6, 670047 Ulan-Ude, Russia.
authors.forename: Daniil N
authors.initials: DN
authors.lastname: Olennikov
authors.affiliation: Department of Ecological Parasitology, I.D. Papanin Institute for Biology of Inland Water, Russian Academy of Sciences, Borok, 152742 Yaroslavl Province, Russia.
authors.forename: Janetta V
authors.initials: JV
authors.lastname: Korneva
authors.affiliation: Institute of General and Experimental Biology, Siberian Branch of Russian Academy of Sciences, Sakhyanovoi st. 6, 670047 Ulan-Ude, Russia.
authors.forename: Olga E
authors.initials: OE
authors.lastname: Mazur
mesh_terms: D000818:Animals; D015232:Dinoprostone / Q000378:metabolism*; D004170:Diphyllobothrium / Q000276:immunology* / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D056747:Immunomodulation; D009411:Nerve Endings / Q000378:metabolism / Q000648:ultrastructure; D009420:Nervous System / Q000276:immunology / Q000378:metabolism; D015230:Prostaglandin D2 / Q000378:metabolism*; D013057:Spectrum Analysis
chemical_list: D015232:Dinoprostone; D015230:Prostaglandin D2
keywords: Cestode; Flame cells; Immunomodulators; Muscles; Nervous system; Prostaglandins