Synthesis and Immunological Characterization of Toll-Like Receptor 7 Agonistic Conjugates


Activation of toll-like receptors (TLRs) on cells of the innate immune system initiates, amplifies, and directs the antigen-specific acquired immune response. Ligands that stimulate TLRs, therefore, represent potential immune adjuvants. In this study, a potent TLR7 agonist was conjugated to phospholipids, poly(ethylene glycol) (PEG), or phospholipid-PEG via a versatile benzoic acid functional group. Compared to the unmodified TLR7 agonist, each conjugate displayed a distinctive immunological profile in vitro and in vivo. In mouse macrophages and human peripheral blood mononuclear cells, the phospholipid TLR7 agonist conjugate was at least 100-fold more potent than the free TLR7 ligands, while the potency of PEG-phospholipid conjugate was similar to that of the unmodified TLR7 agonist. When administered systemically in mice, the phospholipid and phospholipid-PEG TLR7 conjugates induced prolonged increases in the levels of proinflammatory cytokines in serum, compared to the unmodified TLR7 activator. When the conjugates were used as adjuvants during vaccination, only the phospholipid TLR7 agonist conjugates induced both Th1 and Th2 antigen-specific immune responses. These data show that the immunostimulatory activity of a TLR7 ligand can be amplified and focused by conjugation, thus broadening the potential therapeutic application of these agents.

DOI: 10.1021/bc900054q

Extracted Key Phrases

5 Figures and Tables

Citations per Year

77 Citations

Semantic Scholar estimates that this publication has 77 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@inproceedings{Chan2009SynthesisAI, title={Synthesis and Immunological Characterization of Toll-Like Receptor 7 Agonistic Conjugates}, author={Michael F. S. Chan and Tomoko Hayashi and Crystal S. Kuy and Christine S. Gray and Christina C. N. Wu and Maripat Corr and Wolfgang Wrasidlo and Howard B Cottam and Dennis Carson}, booktitle={Bioconjugate chemistry}, year={2009} }