Innate Immunity

A Double Escapee

Science Signaling  04 Sep 2012:
Vol. 5, Issue 240, pp. ec232
DOI: 10.1126/scisignal.2003546

The Toll-like receptors (TLRs) TLR2 and TLR7 are thought to contribute to the sensing of Gram-positive bacteria, such as Staphylococcus aureus and Streptococcus pneumonia, by the immune system. Mice deficient in these receptors, however, are still sensitive to infection with these bacteria. Oldenburg et al. now demonstrate that TLR13 also plays a role in detecting Gram-positive bacteria. TLR13 recognized a conserved region in the peptidyl transferase loop of bacterial 23S ribosomal RNA (rRNA). Intriguingly, this same sequence is modified by specific methyltransferases that confer resistance to erythromycin. Indeed, erythromycin-resistant bacteria were no longer detectible by TLR13.

M. Oldenburg, A. Krüger, R. Ferstl, A. Kaufmann, G. Nees, A. Sigmund, B. Bathke, H. Lauterbach, M. Suter, S. Dreher, U. Koedel, S. Akira, T. Kawai, J. Buer, H. Wagner, S. Bauer, H. Hochrein, C. J. Kirschning, TLR13 recognizes bacterial 23S rRNA devoid of erythromycin resistance–forming modification. Science 337, 1111–1115 (2012). [Abstract] [Full Text]