Open AccessIdentification and Functional Characterization of Chicken Toll-Like Receptor 5 Reveals a Fundamental Role in the Biology of Infection with Salmonella enterica Serovar Typhimurium
Author(s) -
Muhammad Iqbal,
Victoria J. Philbin,
G. S. K. Withanage,
Paul Wigley,
Richard K. Beal,
Marianne Goodchild,
Paul Barrow,
Ian McConnell,
Duncan J. Maskell,
John R. Young,
Nat Bumstead,
Yvonne Boyd,
Adrian L. Smith
Publication year - 2005
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.73.4.2344-2350.2005
Subject(s) - tlr5 , flagellin , biology , salmonella enterica , salmonella , microbiology and biotechnology , serotype , mutant , toll like receptor , flagellum , receptor , innate immune system , gene , genetics , bacteria
Toll-like receptors (TLRs) are a major component of the pattern recognition receptor repertoire that detect invading microorganisms and direct the vertebrate immune system to eliminate infection. In chickens, the differential biology of Salmonella serovars (systemic versus gut-restricted localization) correlates with the presence or absence of flagella, a known TLR5 agonist. Chicken TLR5 (chTLR5) exhibits conserved sequence and structural similarity with mammalian TLR5 and is expressed in tissues and cell populations of immunological and stromal origin. Exposure of chTLR5+ cells to flagellin induced elevated levels of chicken interleukin-1beta (chIL-1beta) but little upregulation of chIL-6 mRNA. Consistent with the flagellin-TLR5 hypothesis, an aflagellar Salmonella enterica serovar Typhimurium fliM mutant exhibited an enhanced ability to establish systemic infection. During the early stages of infection, the fliM mutant induced less IL-1beta mRNA and polymorphonuclear cell infiltration of the gut. Collectively, the data represent the identification and functional characterization of a nonmammalian TLR5 and indicate a role in restricting the entry of flagellated Salmonella into systemic sites of the chicken.