Interferon-like activity produced by anterior kidney leucocytes of rainbow trout stimulated in vitro by infectious hematopoietic necrosis virus or Poly I:C

Abstract

Leucocytes from the anterior ludneys of rainbow trout Oncorhynchus rnykiss produced an interferon-like cytokine (ILC) or cytokines when stimulated wlth free infectious hematopoietic necrosls (IHN) virus, with cell membrane-associated (CMA) IHN virus on glutaraldehyde-fixed chinook salmon embryo cells, or with the synthetic polyribonucleotide Poly 1:C. Peak yields of ILC were similar in leucocyte cultures stimulated by free virus or by CMA virus at optlrnal multiplicities of infection. The antiviral activity had both acid-resistant and acid-labile components, indicating production of several cytokines. Moreover, activity produced by free virus-stimulated leucocytes was significantly (p I 0.05) more resistant to treatment at pH 2 than was activity produced by CMA virus-stimulated leucocytes. Leucocyte populations enriched for macrophages (but not for neutrophils or lymphocytes) demonstrated a significantly enhanced capacity for ILC production after stimulation by Poly 1:C or free IHN virus. The capacity of macrophages for ILC production may be a n important element of the nonspecific resistance of salmonids to IHN virus.

Induction of Mx protein by interferon and double-stranded RNA in salmonid cells

“…This is in accordance with studies of IFN induction in rainbow trout kidney leucocytes by exposure to various viruses or poly I:C (Congleton & Sun, 1996;Rogel Gaillard et al, 1993). The large variation in activity obtained from macrophages of di#erent salmon batches may be due to di#erences in the life history of the fish, like experiences of stress or infections.…”

Aquabirnavirus-induced Protection of Marine Fish against Piscine Nodavirus Infection

“…The current effort was prompted by our previous work on the ability of the ABV to induce protection against VHSV in Japanese flounder (Pakingking et al, 2003(Pakingking et al, , 2004. There have been also extensive in vivo and in vitro studies on the induction of non-specific protection by IFN-like activity in salmonids, in which a number of fish-pathogenic double-stranded or negative-stranded RNA viruses like infectious pancreatic necrosis virus (IPNV), VHSV, infectious hematopoietic necrosis virus (IHNV), and infectious salmon anemia virus (ISAV) were used in addition to dsRNA polyinosinic polycytidylic acid (poly I:C) (Eaton, 1990;Rogel-Gaillard et al, 1993;Congleton et al, 1996;. To our knowledge, this is the first report to document the in vivo effect of IFN-like substance(s) against a positive-sense ssRNA virus; betanodaviruses.…”

An antiviral state induced in Chinook salmon embryo cells (CHSE-214) by transfection with the double-stranded RNA poly I:C

“…The type I IFNs convert host cells in to an antiviral state by inducing expression of proteins that inhibit virus replication, including 2 ,5 -oligoadenylate synthetase, dsRNA dependent protein kinase (PKR) and Mx proteins [1,2]. In salmonids, induction of type I IFN-like activity by dsRNA or virus infection has been demonstrated by several workers [3][4][5][6][7][8][9][10]. However, IFN genes have yet to be cloned from fish.…”

“…The synthetic dsRNA, polyinosinic polycytidylic acid (poly I:C), is a potent inducer of type I IFN both in mammals [17,18] and fish [3,6,9]. Cell lines from Atlantic salmon treated with poly I:C express Mx protein and become protected against infection with infectious pancreatic necrosis virus (IPNV) [6,7].…”