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Auxiliary role for d ‐alanylated wall teichoic acid in Toll‐like receptor 2‐mediated survival of Staphylococcus aureus in macrophages
Author(s) -
Shiratsuchi Akiko,
Shimizu Kaori,
Watanabe Ikuko,
Hashimoto Yumi,
Kurokawa Kenji,
Razanajatovo Iony M.,
Park Keun H.,
Park Hae K.,
Lee Bok L.,
Sekimizu Kazuhisa,
Nakanishi Yoshinobu
Publication year - 2010
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2009.03168.x
Subject(s) - teichoic acid , mutant , cell wall , tlr2 , lipoteichoic acid , microbiology and biotechnology , staphylococcus aureus , biology , cell envelope , kinase , bacterial cell structure , phosphorylation , alanine , biochemistry , toll like receptor , receptor , bacteria , peptidoglycan , amino acid , innate immune system , gene , escherichia coli , genetics
Summary We previously reported that Staphylococcus aureus avoids killing within macrophages by exploiting the action of Toll‐like receptor 2 (TLR2), which leads to the c‐Jun N‐terminal kinase (JNK)‐mediated inhibition of superoxide production. To search for bacterial components responsible for this event, a series of S. aureus mutants, in which the synthesis of the cell wall was interrupted, were screened for the level of JNK activation in macrophages. In addition to a mutant lacking the lipoproteins that have been suggested to act as a TLR2 ligand, two mutant strains were found to activate the phosphorylation of JNK to a lesser extent than the parental strain, and this defect was recovered by acquisition of the corresponding wild‐type genes. Macrophages that had phagocytosed the mutant strains produced more superoxide than those engulfing the parental strain, and the mutant bacteria were more efficiently killed in macrophages than the parent. The genes mutated, dltA and tagO , encoded proteins involved in the synthesis of d ‐alanylated wall teichoic acid. Unlike a cell wall fraction rich in lipoproteins, d ‐alanine‐bound wall teichoic acid purified from the parent strain by itself did not activate JNK phosphorylation in macrophages. These results suggest that the d ‐alanylated wall teichoic acid of S. aureus modulates the cell wall milieu for lipoproteins so that they effectively serve as a ligand for TLR2.