Agonists of Toll-like receptors (TLRs) are potent activators of the innate immune system and hold promise as vaccine adjuvant and for anticancer immunotherapy. Unfortunately, in soluble form they readily enter systemic circulation and cause systemic inflammatory toxicity. Here we demonstrate that by covalent ligation of a smallmolecule imidazoquinoline-based TLR7/8 agonist to 50-nm-sized degradable polymeric nanogels the potency of the agonist to activate TLR7/8 in in vitro cultured dendritic cells is largely retained. Importantly, imidazoquinoline-ligated nanogels focused the in vivo immune activation on the draining lymph nodes while dramatically reducing systemic inflammation. Mechanistic studies revealed a prevalent passive diffusion of the nanogels to the draining lymph node. Moreover, immunization studies in mice have shown that relative to soluble TLR7/8 agonist, imidazoquinoline-ligated nanogels induce superior antibody and T-cell responses against a tuberculosis antigen. This approach opens possibilities to enhance the therapeutic benefit of small-molecule TLR agonist for a variety of applications.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Jul 19 2016|
Bibliographical noteFunding Information:
We thank Dr. Kris Huygen and Dr. Marta Romano for providing the PPE44 peptide epitopes and for their scientific support. This work was supported by the Research Foundation-Flanders (FWO) and the Flemish Liga Against Cancer (B.G.D.G.), an FWO postdoctoral grant (to S.D.K.), an Alexander von Humboldt Foundation postdoctoral Feodor Lynen research fellowship (to L.N.), Special Research Fund (BOF)-UGent and Agency for Innovation by Science and Technology (IWT) Flanders PhD scholarships (to N.V., A.D.B., L.L., and G.V.), and National Institutes of Health (NIH) National Institute of Allergy and Infectious Diseases (NIAID) Contract HSN272200900033C (to S.A.D.).
- Dendritic cells
- Lymph node
- Toll-like receptor