MD-2 enables Toll-like receptor 2 (TLR2)-mediated responses to lipopolysaccharide and enhances TLR2-mediated responses to gram-positive and gram-negative bacteria and their cell wall components

R. Dziarski, Q. Wang, K. Miyake, C. J. Kirschning, D. Gupta

Research output: Contribution to journalArticle

160 Scopus citations


MD-2 is associated with Toll-like receptor 4 (TLR4) on the cell surface and enables TLR4 to respond to LPS. We tested whether MD-2 enhances or enables the responses of both TLR2 and TLR4 to Gram-negative and Gram-positive bacteria and their components. TLR2 without MD-2 did not efficiently respond to highly purified LPS and LPS partial structures. MD-2 enabled TLR2 to respond to nonactivating protein-free LPS, LPS mutants, or lipid A and enhanced TLR2-mediated responses to both Gram-negative and Gram-positive bacteria and their LPS, peptidoglycan, and lipoteichoic acid components. MD-2 enabled TLR4 to respond to a wide variety of LPS partial structures, Gram-negative bacteria, and Gram-positive lipoteichoic acid, but not to Gram-positive bacteria, peptidoglycan, and lipopeptide. MD-2 physically associated with TLR2, but this association was weaker than with TLR4. MD-2 enhanced expression of both TLR2 and TLR4, and TLR2 and TLR4 enhanced expression of MD-2. Thus, MD-2 enables both TLR4 and TLR2 to respond with high sensitivity to a broad range of LPS structures and to lipoteichoic acid, and, moreover, MD-2 enhances the responses of TLR2 to Gram-positive bacteria and peptidoglycan, to which the TLR4-MD-2 complex is unresponsive.

Original languageEnglish (US)
Pages (from-to)1938-1944
Number of pages7
JournalJournal of Immunology
Issue number3
StatePublished - Feb 1 2001


ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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