Legionella pneumophila Suppresses Interleukin-12 Production by Macrophages
AUTOR(ES)
Matsunaga, Kazuto
FONTE
American Society for Microbiology
RESUMO
In vitro infection of macrophages with Legionella pneumophila induced interleukin-1α (IL-1α), IL-10, monocyte chemotactic protein 1 (MCP-1), and MCP-3 but not IL-12. The lipopolysaccharide (LPS)-induced production of IL-12 was down-regulated by infection with virulent L. pneumophila, but other cytokines were not affected. In contrast, avirulent L. pneumophila or UV-killed, virulent L. pneumophila did not induce any suppression of IL-12. The IL-12 suppression occurred at the level of mRNA accumulation for IL-12 genes in response to LPS stimulation, but the infection induced a marked accumulation of mRNA for both MCP-1 and MCP-3, which are known to suppress IL-12 production in LPS-stimulated macrophages. However, pretreatment of macrophages with MCP-1 did not suppress LPS-induced IL-12 production at the concentrations induced by L. pneumophila infection. These results suggest that L. pneumophila selectively suppresses IL-12 production induced by LPS from macrophages in vitro by an MCP-independent mechanism.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=98106Documentos Relacionados
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