Related Experiment Video
Updated: Jul 16, 2026
07:04
Immunostimulatory Agent Evaluation: Lymphoid Tissue Extraction and Injection Route-Dependent Dendritic Cell Activation
Published on: September 16, 2018
Immunostimulatory CpG oligonucleotides form defined three-dimensional structures: results from an NMR study
Guangyu He1, Amritraj Patra, Karsten Siegmund
1Institute of Organic Chemistry, University of Karlsruhe TH, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
Chemmedchem
|March 17, 2007
Summary
This study used NMR to investigate DNA structures that activate the innate immune system via Toll-like receptor 9 (TLR9). Findings reveal structural changes beyond the core sequence, crucial for understanding DNA-TLR9 molecular recognition.
Area of Science:
- Immunology
- Molecular Biology
- Biophysics
Background:
- Vertebrate innate immunity involves DNA recognition by Toll-like receptor 9 (TLR9).
- The immunostimulatory DNA eicosamer 5'-TCCATGACGTTCCTGATGCT-3' requires an unmethylated CG dinucleotide for activity.
- The precise structural basis for DNA recognition by TLR9 remains largely unelucidated.
Purpose of the Study:
- To elucidate the structural basis of DNA recognition by Toll-like receptor 9 (TLR9).
- To investigate the structural properties of immunostimulatory DNA sequences using NMR spectroscopy.
Main Methods:
- Proton Nuclear Magnetic Resonance ((1)H NMR) spectroscopy was employed.
- Two-dimensional NMR spectra were used for resonance assignment.
- Structural transitions upon heating were monitored via line width and chemical shift changes.
Main Results:
- Structural transitions were observed in DNA oligonucleotides ranging from hexamers to pentaeicosamers upon heating.
- Resonances were unambiguously assigned using 2D NMR.
- Structure formation was detected extending beyond the core 5'-GACGTT-3' hexamer, including the 5'-terminal TC dinucleotide.
Conclusions:
- DNA structure formation extends beyond the minimal TLR9-activating core sequence.
- These extended structural features may play a significant role in the molecular recognition by Toll-like receptors.
- Understanding these DNA structural dynamics is key to deciphering innate immune system activation pathways.
