Pathogenesis of Iridovirus: in vitro Influence on Macrophage Activity and Cytokine-Like Protein Production in Fish

摘要: Siwicki A. , F. Pozet M. Morand, E. Terech-Majewska, D. Bernard: Pathogenesis of Iridovirus: in Vitro Influence on Macrophage Activity and Cytokine-Like Protein Production In Fish. Acta Vet. Brno, 2001, 70: 451–456. recent years, iridovirus-like agents have been recognized as the cause several diseases fish. An pathogen isolated from catfish (Ictalurus melas) was tested vitro macrophage activity cytokine-like protein (IL-1, IL-6) production carp (Cyprinus carpio L.), rainbow trout (Oncorhynchus mykiss) sheatfish (Silurus glanis L.). The influence iridovirus pronephric examined by studying respiratory burst (RBA) potential killing (PKA) well cytokines leukocytes stimulated ConA. results showed that decreased RBA PKA carp, sheatfish. highest inhibitory effect observed (70 % activity), compared to (35 activity) (20 activity). had a similar pattern. significantly (P < 0.05) IL-1-like IL-6-like observed. This preliminary comparative study demonstrated suppressive sheatfish, but immunosuppressive Iridovirus, fish, macrophage, cytokines, RBA, Iridoviruses, large double-stranded cytoplasmic DNA viruses, infect different insect vertebrate hosts. major structural component non-enveloped icosahedral virus particles is capsid protein, which appears be highly conserved among members family Iridoviridae, Phycodnaviridae African swine fever virus. There are viruses appear distantly related iridoviruses including endosymbiotic algae (Coggius 1974; Ahne et al. 1990). common property these essential steps transcription, replication assembly take place cytoplasm host cells. experimental need cell nucleus for productive infection (Ahne 1997). One most interesting features iridoviruses, phycodnaviruses, significant homology between amino acid sequences their 1997; Tidona al.1998). Vertebrate found amphibians reptiles. Many new iridoviruses-like described species Their morphological biological characteristics clearly separate them Address correspondence: Professor Andrzej K. DVM, PhD, DSc Department Microbiology Clinical Immunology Faculty Veterinary Medicine, University Olsztyn, 10-957 Olsztyn – Kortowo II, Poland Phone:+48 22 756 24 90 Fax: +48 E-mail: irs@warman.com.pl; siwicki@moskit.uwm.edu.pl http://www.vfu.cz/acta-vet/actavet.htm fish associated with lymphocystis disease (LD), epizootic haematopoietic necrosis (EHN) epidermal infections. To date, mechanisms involved penetration into not understood. presented severe lesions were pronephros, spleen, vascular system. characteristic feature generalized acute renal tissue. Macrophages neutrophils interstitial tissue harboured phagosomes. Residual degenerating cells numerous viral subunit assemblies 1990; reports effects mitogenstimulated Materials Methods Animals cel ls separat ion pronephros culture performed healthy L.) mean weight 100 g, according method Bayne (1985) salmonid Secombes (1990). Before dissection, 20 each anaesthetized Propiscin (IFI, Poland) bled caudal vein (Vacutainer systems, Bencton Dickinson) reduce blood volume pronephros. Single suspensions obtained placing RPMI-1640 (Sigma) medium teasing it through steel mesh. They Histopaque1077 or Ficoll-Paque (density 1.077 g/ml), Pharmacia) gradients. Cel l ine Laboratoire Departemental d’Analyses (LDA 39) France (59.90) used this quantified plaque assay using Epithelioma papulosum cyprini (EPC) incubated at °C 72 h. EPC line MEM (BHK21 Medium, Glasgow minimum medium, Life Technologies, USA) 10 tryptose phosphate broth (Difco) foetal calf serum (FCS, Technologies) grow iridovirus, (1992). For production, FCS content reduced 2 pH adjusted 7.6 (Pozet 1992). Immunological assays A modification (1990) macrophages Phorbol myristate acetate (PMA, Sigma; stock solution: 50 μg/ml ethanol, kept frozen –20 °C). Cell suspension (100 μl; concentration 1×106 /well RPMI-1640) distributed 96-well plates (Nunclon) μl 1 × 105 plaque-forming units/ml h 14 After incubation, non-adherent removed washing RPMI medium. replaced ml RPMI, nitro blue tetrazolium (NBT Sigma) solution (2 RPMI) without PMA (Sigma). 30 min after NBT wells washed thoroughly metanol. order measure H2O2 read micro reader (Optical density 620 nm; Labsystems iEMS Reader MF, Finland). Anderson (1993) technique Rook macrophages. 0.2 (Sigma, PBS containing living Aeromonas hydrophila (1 108 bacteria/ml) °C. second part our study, interleukin 1-like (IL-1-like protein) 6-like (IL-6-like investigated, previously (1994). separated ml) 24well 106 cells/ml supplemented with: ConA RPMI), + (at doses only temperature control FCS. incubation supernatant stored prior assay. levels interleukins evaluated ELISA (Genzyme kits, USA). 452