ИСТИНА

Kutyrev I., Scharsack J.P., Biserova N.M., Kurtz J. 2012. Prostaglandin E2 as a Cestodes immunomodulator. In proceeding of: The XI-th European Multicolloquium of Parasitology (EMOP XI), At Cluj-Napoca, Romania, Volume: 1 ABSTRACT Parasitic worms can survive in the host body for a long time due to their ability to control the immune response. Prostaglandins synthesized by parasites form an important class of immunomodulators. The mechanisms underlying immunoregulation of the host body with prostaglandins are poorly studied, and there is no evidence of prostaglandin functioning in cestodes. Prostaglandin E2 (PG E2) is the most important immunomodulator among prostaglandins. The present study investigated distribution of PG E2 in the organism of Diphyllobothrium dendriticum and influence of PG E2 on the cell culture of sticklebacks head kidney leukocytes. D. dendriticum plerocercoids have been withdrawn from Baikal omul. The sections of plerocercoids were incubated with monoclonal antibodies against PG E2 and α-tubulin, than with secondary antibodies. This was followed by examination with the aid of laser scanning confocal microscope. We have analyzed the frequency of leukocyte subsets (granulocyte to lymphocyte ratio) and production of reactive oxygen species (ROS), of head kidney leukocytes (HKL) isolated from sticklebacks following in vitro stimulation with PG E2 and with S. solidus conditioned cell culture medium. PG E2-IR was revealed in cortical parenchyma cells with long processes passed through subtegument and tegument, and formed bulbar-shape protrusion at the surface of the distal cyto-plasm. Co-localization of the PG E2-IR and α-tubulin-IR was found in tegument, subtegument and cortical parenchyma cells. A specific α-tubulin-IR was revealed in cells with long processes directed to the tegument. These processes are penetrated distal cytoplasm and formed bulbar-like protrusions on the tegumental surface. A specific PG E2-IR lay inside of the α-tubulin-IR loci. PG E2-like immnoreactivity of cells having IR against α-tubulin has been determined for the first time. Judging from their location and terminal frontal glands, these elements fulfill an immunoregulatory function; their glands synthesize prostaglandin E2 and release it into host cells. PG E2 has strong influence on HKL both immediately and after 4 days of incubation. It supressed respiratory burst alone and with extracts of S. solidus and LPS. It decreases the leucocyte number, mostly lymphocytes. As compared with extracts of S. solidus and LPS, PG E2 has inverse action. We can see that PG E2 influence the sticklebacks HKL. But in any cases they have effect not similar to S. solidus. However, from another hand, extract of S. solidus is a mix of different biologically active substances. Therefore we need in more detailed investigation of biochemical composition of Cestodes parasiting in fishes.