Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 13, 2011
Publication Date: July 15, 2011
Citation: Sacco, R.E., Nicholson, T.L., Waters, T.E., Brockmeier, S. 2011. Porcine TLR3 characterization and expression in response to influenza virus and Bordetella bronchiseptica. Veterinary Immunology and Immunopathology. 142(1-2):57-63. Interpretive Summary: We have sequenced the gene for a protein expressed by white blood cells that is involved in the early immune response to bacteria and viruses. In this paper, we then show how the expression of this protein changes in response to bacterial and/or viral infection in pigs. Our findings are important in that we show that different types of viruses may modify this protein in pigs in different ways.
Technical Abstract: We have provided a detailed structural analysis of porcine alveolar macrophage TLR3 extracellular domain (ECD). The pTLR3-ECD contains 18 leucine-rich repeat (LRRs) consisting of blocks of consensus motifs and non-consensus motifs containing insertions. Excluding the N-terminal and C-terminal LRRs, pTLR3 has two LRRs with insertions, resulting in one LRR of 39 amino acids and another LRR of 34 amino acids. Furthermore, we have conducted the first examination of the regulated expression of porcine alveolar macrophage TLR3 during in vivo co-infection with influenza virus and Bordetella bronchiseptica. There was a bi-phasic upregulation of pTLR3 during influenza virus infection (day 1 and day 10 postinfection). Co-infection resulted in an enhanced expression of pTLR3 only at day 1 PI. Interestingly, B. bronchiseptica induced an upregulation in alveolar macrophage TLR3 expression at day 10 PI. Based on our work and that of others, the data suggest that there is a differential regulation of porcine AMphi TLR3 in response to positive- and negative-sense RNA viruses.