UMMS Affiliation

Department of Medicine, Division of Infectious Diseases and Immunology

Publication Date


Document Type



Biochemistry, Biophysics, and Structural Biology | Immunology and Infectious Disease | Infectious Disease


The pneumococcal type 1 pilus is an inflammatory and adherence-promoting structure associated with increased virulence in mouse models. We show that RrgA, an ancillary pilus subunit devoid of a lipidation motif, particularly when presented as part of an oligomer, is a TLR2 agonist. The surface-exposed domain III, and in particular a 49-amino acid sequence (P3), of the protein is responsible for the TLR2 activity of RrgA. A pneumococcal mutant carrying RrgA with a deletion of the P3 region was significantly reduced in its ability to activate TLR2 and induce TNF-alpha responses after mouse intraperitoneal infection, whereas no such difference could be noted when TLR2(-/-) mice were challenged, further implicating this region in recognition by TLR2. Thus, we conclude that the type 1 pneumococcal pilus can activate cells via TLR2, and the ancillary pilus subunit RrgA is a key component of this activation.


Bacterial Pathogenesis, Cell Surface Protein, Streptococcus, Toll-like Receptors (TLR), Virulence Factors

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© 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Publisher PDF posted after 12 months as allowed by the publisher's author rights policy at

DOI of Published Version



J Biol Chem. 2013 Jan 25;288(4):2665-75. doi: 10.1074/jbc.M112.398875. Epub 2012 Dec 11. Link to article on publisher's site

Journal/Book/Conference Title

The Journal of biological chemistry

Related Resources

Link to Article in PubMed

PubMed ID