Classical swine fever virus inhibits nitric oxide production in infected macrophages

Classical swine fever virus (CSFV)-macrophage interactions during infection were analysed by examining macrophage transcriptional responses via microarray. Eleven genes had increased mRNA levels (> 2.5-fold, P < 0.05) in infected cell cultures, including arginase-1, an inhibitor of nitric oxide production, phosphoinositide 3-kinase, chemokine receptor 4 and interleukin-1 beta Lower levels of nitric oxide and increased arginase activity were found in CSFV-infected macrophages. These changes in gene expression in macrophages suggest viral modulation of host expression to suppress nitric oxide production.