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Structures of TLR-ligand complexes

Mi Sun Jin1, Jie-Oh Lee

  • 1Department of Chemistry and Institute for the Bio-Century, KAIST, 373-1 Kusong-dong, Yusong-gu, Daejeon, Republic of Korea.

Current Opinion in Immunology
|July 1, 2008
PubMed

Insights

Toll-like receptors (TLRs) are key to innate immunity. Structural studies reveal how TLRs bind diverse microbial molecules, forming

Area of Science:

  • Immunology
  • Structural Biology
  • Biochemistry

Background:

  • Toll-like receptors (TLRs) are crucial pattern recognition receptors in the innate immune system.
  • They identify conserved molecular patterns from microbes, initiating immune responses.
  • Understanding TLR structure and ligand interaction is vital for immunology research.

Purpose of the Study:

  • To review recent high-resolution crystal structures of four TLRs and their ligand complexes.
  • To discuss proposed activation mechanisms based on these structural insights.
  • To explore the structural deviations of TLRs from canonical leucine-rich repeat (LRR) proteins.

Main Methods:

  • High-resolution X-ray crystallography was employed to determine TLR structures.
  • Analysis of structural data for four TLRs and their complexes with various ligands.
  • Comparative analysis of TLR structures against canonical LRR proteins.

Main Results:

  • Structures reveal TLRs deviate significantly from canonical LRR structures.
  • TLRs interact with a wide array of ligands in a highly diverse manner.
  • Agonistic ligands induce an 'm'-shaped TLR dimer formation where C-termini converge.

Conclusions:

  • The observed structural rearrangement in TLR dimers suggests a common activation mechanism across the TLR family.
  • These findings provide critical insights into the molecular basis of innate immune recognition.
  • Structural data advances the understanding of TLR function in host defense.

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