Induction and persistence of Mx protein in tissues, blood and plasma of Atlantic salmon parr, Salmo salar, injected with poly I:C.
ABSTRACT The expression of Mx transcripts and Mx protein was monitored at weekly intervals for 7 weeks, by qRT-PCR and immunohistochemistry, in the kidney, liver, gill and blood of Atlantic salmon parr following injection of poly I:C. Elevated levels of Mx transcripts compared to PBS injected control fish were found in the tissues at week 1. Background levels were then found up to week 7, with the exception of week 4 when high levels were again found in poly I:C injected fish as well as control fish. Immunostaining for Mx protein in the kidney, liver and gill of poly I:C injected fish was higher than in control fish from weeks 1-4, but little staining was found in the tissues of both poly I:C treated and control fish thereafter. Blood monocytes stained consistently in all fish, suggesting that this leucocyte type constitutively expressed Mx protein. From weeks 2-4, lymphocytes of both groups consistently stained for Mx protein but the consistency decreased at weeks 5-7. Staining of neutrophils was also inconsistent. Western blots of plasma showed an immunoreactive band of 76 kDa typical of salmon Mx protein. Semi-quantitative measurements of dot blots showed poly I:C injected fish to have higher levels of plasma Mx protein than controls on weeks 1-4 with very low levels on weeks 5-7. The results indicate that following induction of an interferon response with poly I:C, Atlantic salmon parr maintain elevated levels of Mx protein in tissues, leucocytes and blood plasma for about 4 weeks. Production of Mx protein by blood monocytes appears to be constitutive, though production by lymphocytes and neutrophils was less consistent.
- SourceAvailable from: Bergljot Magnadottir[show abstract] [hide abstract]
ABSTRACT: All metazoans possess innate immune defence system whereas parameters of the adaptive immune system make their first appearance in the gnathostomata, the jawed vertebrates. Fish are therefore the first animal phyla to possess both an innate and adaptive immune system making them very interesting as regards developmental studies of the immune system. The massive increase in aquaculture in recent decades has also put greater emphasis on studies of the fish immune system and defence against diseases commonly associated with intensive fish rearing. Some of the main components of the innate and adaptive immune system of fish are described. The innate parameters are at the forefront of immune defence in fish and are a crucial factor in disease resistance. The adaptive response of fish is commonly delayed but is essential for lasting immunity and a key factor in successful vaccination. Some of the inherent and external factors that can manipulate the immune system of fish are discussed, the main fish diseases are listed and the pathogenicity and host defence discussed. The main prophylactic measures are covered, including vaccination, probiotics and immunostimulation. A key element in the immunological control of fish diseases is the great variation in disease susceptibility and immune defence of different fish species, a reflection of the extended time the present day teleosts have been separated in evolution. Future research will probably make use of molecular and proteomic tools both to study important elements in immune defence and prophylactic measures and to assist with breeding programmes for disease resistance.Marine Biotechnology 03/2010; 12(4):361-79. · 2.74 Impact Factor
Conference Proceeding: Metrology for analog module testing using analog testability bus[show abstract] [hide abstract]
ABSTRACT: In this paper, we propose a method to generate high quality test waveform on chip to avoid the parasitic effects in an analog testability bus test environment. For the test response analysis, we derive an extraction methodology to remove the parasitic effects and obtain the intrinsic response of the CUT. The test results show that the algorithm is robust such that the intrinsic responses remain the same regardless of the small variation in the test waveforms. With the concept of intrinsic responses, we are able to use a single library for the testing and diagnosis of multiple instantiation of an analog moduleComputer-Aided Design, 1996. ICCAD-96. Digest of Technical Papers., 1996 IEEE/ACM International Conference on; 12/1996
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ABSTRACT: IPNV is the agent of a well-characterized acute disease that produces a systemic infection and high mortality in farmed fish species and persistent infection in surviving fish after outbreaks. Because modulation of the host expression of pro and anti-inflammatory cytokines can help establish persistence, in this study, we examined the expression of IL-1β, IL-8, IFNα1 and IL-10 during acute and persistent IPNV infection of Atlantic salmon. Results showed that IPNV infection induces an increase of the IFNα1 and IL-10 mRNA levels in the spleen and head kidney (HK) of fish after acute experimental infection. Levels of the pro-inflammatory cytokines IL-1β and IL-8 did not rise in the spleen although an increase of IL-1β, but not of IL-8, was observed in head kidney. In carrier asymptomatic salmon, cytokine gene expression of IFNα1 in the spleen and IL-10 in head kidney were also significantly higher than expression in non-carrier fish. Interestingly, a decrease of IL-8 expression was also observed. IPNV infection of SHK-1, which is a macrophage-like cell line of salmon, also induced an increase of expression of the anti-inflammatory cytokine IL-10 with no effects on the expression of IL-1β and IL-8. The effects are induced by an unknown mechanism during viral infection because poly I:C and the viral genomic dsRNA showed the opposite effects on cytokine expression in SHK-1 cells. In summary, IPNV always induces up-regulation of the anti-inflammatory cytokine IL-10 in Atlantic salmon. As this is accompanied by a lack of induction of the pro-inflammatory cytokines IL-1β and IL-8, the anti-inflammatory milieu may explain the high frequency, prevalence and persistence of IPNV in salmon. Effects might be part of the viral mechanisms of immune evasion.Fish & Shellfish Immunology 11/2011; 32(2):291-300. · 2.96 Impact Factor