This article is available from: http://www.biomedcentral.com/1471-2164/9/141
[Background] The response of the trout, O. mykiss, head kidney to bacterial lipopolysaccharide
(LPS) or active and attenuated infectious hematopoietic necrosis virus (IHNV and attINHV
respectively) intraperitoneal challenge, 24 and 72 hours post-injection, was investigated using a
salmonid-specific cDNA microarray.
[Results] The head kidney response to i.p. LPS-induced inflammation in the first instance displays
an initial stress reaction involving suppression of major cellular processes, including immune
function, followed by a proliferative hematopoietic-type/biogenesis response 3 days after
administration. The viral response at the early stage of infection highlights a suppression of
hematopoietic and protein biosynthetic function and a stimulation of immune response. In fish
infected with IHNV a loss of cellular function including signal transduction, cell cycle and
transcriptional activity 72 hours after infection reflects the tissue-specific pathology of IHNV
infection. attIHNV treatment on the other hand shows a similar pattern to native IHNV infection
at 24 hours however at 72 hours a divergence from the viral response is seen and replace with a
recovery response more similar to that observed for LPS is observed.
[Conclusion] In conclusion we have been able to identify and characterise by transcriptomic
analysis two different types of responses to two distinct immune agents, a virus, IHNV and a
bacterial cell wall component, LPS and a 'mixed' response to an attenuated IHNV. This type of
analysis will lead to a greater understanding of the physiological response and the development of
effective immune responses in salmonid fish to different pathogenic and pro-inflammatory agents.
This work was supported by Plan Nacional AGL2005-12134 from the Ministerio
de Educación y Ciencia, España and the EU-funded project
IMAQUANIM, EC contract number FOOD-CT-2005-007103.
Peer reviewed