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Comparative analysis of the acute response of the trout, O. mykiss, head kidney to in vivo challenge with virulent and attenuated infectious hematopoietic necrosis virus and LPS-induced inflammation

Simon MacKenzie1*, Joan C Balasch1, Beatriz Novoa2, Laia Ribas3, Nerea Roher4, Aleksei Krasnov5 and Antonio Figueras2

Author Affiliations

1 Unitat de Fisiologia Animal, Departament de Biologia Cellular, de Fisiologia i d'Immunologia, Universitat Autonoma de Barcelona (UAB), Barcelona, Spain

2 Instituto de Investigaciones Marinas, CSIC, Vigo, Spain

3 Imperial College Faculty of Medicine, Dpt of Infectious Disease Epidemiology, London, UK

4 Departament de Fisiologia, Facultat de Biología, Universitat de Barcelona, Barcelona, Spain

5 Akvaforsk, Institutt for akvakulturforskning, Aas, Norway

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BMC Genomics 2008, 9:141  doi:10.1186/1471-2164-9-141

Published: 26 March 2008



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.


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.


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.