Open AccessInterleukin-1 Beta Secretion is Activated Comparably by FliC and FljB Flagellins but Differentially by Wild-Type and DNA Adenine Methylase-DeficientSalmonella
Author(s) -
Raphael Simon,
Charles E. Samuel
Publication year - 2008
Publication title -
journal of interferon and cytokine research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.031
H-Index - 94
eISSN - 1557-7465
pISSN - 1079-9907
DOI - 10.1089/jir.2008.0022
Subject(s) - flagellin , secretion , biology , salmonella , flagellum , microbiology and biotechnology , mutant , salmonella enterica , cytoplasm , gene , bacteria , biochemistry , genetics
Recognition of cytoplasmic bacterial flagellin by the Nod-like receptor ICE protease-activating factor (Ipaf) in macrophages leads to activation of caspase-1 and secretion of interleukin-1beta (IL-1beta). Salmonella possess two genes, fliC and fljB, that encode flagellin proteins. We examined the ability of purified FliC and FljB proteins to activate IL-1beta secretion in the mouse macrophage-like J774 cell line and in mouse primary peritoneal cells. We found that purified FliC and FljB flagellins possessed a comparable ability to activate IL-1beta secretion following introduction into the cytoplasm of J774 or primary cells. We also examined the ability of an attenuated Salmonella mutant strain (dam) deficient in DNA adenine methylase to activate IL-1beta secretion. Compared to infection of primary cells with wild-type Salmonella, IL-1beta secretion was reduced in cells infected with the dam mutant even though the two strains expressed similar levels of flagellin. As a control, cells infected with a flagellin-deficient (flhC) Salmonella strain did not show enhanced IL-1beta secretion.