Rapid and widely disseminated acute phase protein response after experimental bacterial infection of pigs

Abstract

The acute phase protein response is a well-described generalized early host response to tissue injury, inflammation and infection, observed as pronounced changes in the concentrations of a number of circulating serum proteins. The biological function of this response and its interplay with other parts of innate host defence reactions remain somewhat elusive. In order to gain new insight into this early host defence response in the context of bacterial infection we studied gene expression changes in peripheral lymphoid tissues as compared to hepatic expression changes, 14–18 h after lung infection in pigs. The lung infection was established with the pig specific respiratory pathogen Actinobacillus pleuropneumoniae. Quantitative real-time PCR based expression analysis were performed on samples from liver, tracheobronchial lymph node, tonsils, spleen and on blood leukocytes, supplemented with measurements of interleukin-6 and selected acute phase proteins in serum. C-reactive protein and serum amyloid A were clearly induced 14–18 h after infection. Extrahepatic expression of acute phase proteins was found to be dramatically altered as a result of the lung infection with an extrahepatic acute phase protein response occurring concomitantly with the hepatic response. This suggests that the acute phase protein response is a more disseminated systemic response than previously thought. The current study provides to our knowledge the first example of porcine extrahepatic expression and regulation of C-reactive protein, haptoglobin, fibrinogen, pig major acute phase protein, and transferrin in peripheral lymphoid tissues.

Expression of Innate Immune Response Genes in Liver and Three Types of Adipose Tissue in Cloned Pigs

“…Alternatively, the small-scale induction of APP genes seen here may represent a normal physiological response, induced by proinflammatory cytokines not originating from the liver, because the expression of APPs in the liver is affected by disturbance of tissues wherever it may occur (Skovgaard et al, 2009). It is possible that these extrahepatic cytokines could be delivered from the VAT and omental fat via the portal vein as these adipose tissues are drained by the portal circulation.…”

“…Primers were designed using Primer3 (http://frodo.wi .mit.edu/) as described previously (Skovgaard et al, 2009) and synthesized at TAG Copenhagen (Copenhagen, Denmark). Primer sequences and amplicon lengths are shown in Table 1.…”

“…Even if the effects may seem small compared to those observed during a full-blown acutephase response to infection (see, for example, Skovgaard et al, 2009Skovgaard et al, , 2010, such small changes may easily result in long-term phenotypic effects. Investigations in human healthy adults with prolonged acute-phase response in the high-normal range have been shown to have an increased long-term risk of angina, myocardial infarction, cardiovascular disease, and death (Munford, 2001;Ridker et al, 2000).…”

Gene expression responses toRiemerella anatipestiferinfection in the liver of ducks

“…Analysis of the disassociation curves confirmed that fluorescent signal was generated only from specific cDNA transcripts. The housekeeping gene b-actin was used to normalize the level of target gene expression due to its uniform expression levels over a variety of tissue and treatment conditions (Skovgaard et al, 2009;Tian et al, 2009). Each individual sample was run in triplicate.…”

Acute Phase Proteins as Biomarkers in Animal Health and Welfare

“…In pigs experimentally infected by Streptococcus suis showed increased serum concentrations of Hp, CRP, SAA and Pig-MAP (Sorensen et al, 2006). In an experimental infection with Actinobacillus pleuropneumoniae increased serum levels of CRP and SAA were found but extrahepatic expression of these two proteins and of Hp and Pig-MAP was also detected in peripheral lymphoid tissues by PCR (Skovgaard et al, 2009). Extrahepatic presence of Hp has been also detected in lung by immunohistochemistry (Hiss et al, 2008).…”