ISSN:
1432-1211
Keywords:
Key words Pig
;
Cytokine
;
Interleukin-18
;
Chromosomal location
;
Tissue expression
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Interleukin 18 (IL-18), a recently described cytokine, plays an important role in the cell-mediated immune response, in particular through its ability to induce the production of interferon (IFN)-γ. We cloned pig IL-18 cDNA from the intestinal epithelial cell line IPI-2I using a reverse transcriptase-polymerase chain reaction method with primers derived from the human IL-18 sequence. The amino acid sequence deduced from pig IL-18 cDNA encodes a 192 amino-acid polypeptide that exhibits 92, 90, 81, and 71% similarity to IL-18 from horse, dog, human, and rodents (mouse and rat), respectively. Structural comparison of the IL-18 protein with IL-1α and IL-1β showed that IL-18 shares several characteristics with the IL-1 cytokine family: the IL-1 signature-like sequence, a potential caspase-1 (ICE) cleavage site, and the presence of 12 predicted β strands. Fluorescence in situ hybridization was used to localize the IL-18 gene on the short arm (p13) of pig chromosome 9. Analysis of IL-18 expression in different organs of piglets demonstrated that IL-18 mRNA is weakly expressed in the kidney and the lung. By contrast, we observed highly constitutive expression of IL-18 mRNA in the spleen, mesenteric lymph nodes, and the intestine, particularly in the small intestine, indicating a potential role for IL-18 as a first line of host defense in the intestinal mucosa.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002510050630
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