Development of RNA/DNA Hydrogel Targeting Toll-Like Receptor 7/8 for Sustained RNA Release and Potent Immune Activation

Guanosine- and uridine-rich single-stranded RNA (GU-rich RNA) is an agonist of Toll-like receptor (TLR) 7 and TLR8 and induces strong immune responses. A nanostructured GU-rich RNA/DNA assembly prepared using DNA nanotechnology can be used as an adjuvant capable of improving the biological stability of RNA and promoting efficient RNA delivery to target immune cells. To achieve a sustained supply of GU-rich RNA to immune cells, we developed a GU-rich RNA/DNA hydrogel (RDgel) using nanostructured GU-rich RNA/DNA assembly, from which GU-rich RNA can be released in a sustained manner. A hexapod-like GU-rich RNA/DNA nanostructure, or hexapodRD6, was designed using a 20-mer phosphorothioate-stabilized GU-rich RNA and six phosphodiester DNAs. Two sets of hexapodRD6 were mixed to obtain RDgel. Under serum-containing conditions, GU-rich RNA was gradually released from the RDgel. Fluorescently labeled GU-rich RNA was efficiently taken up by DC2.4 murine dendritic cells and induced a high level of tumor necrosis factor-α release from these cells when it was incorporated into RDgel. These results indicate that the RDgel constructed using DNA nanotechnology can be a useful adjuvant in cancer therapy with sustained RNA release and high immunostimulatory activity.

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Soluble forms of Toll-like receptor 4 are present in human saliva and modulate tumour necrosis factor-α secretion by macrophage-like cells

Clinical & Experimental Immunology ◽

10.1111/j.1365-2249.2009.03854.x ◽

2009 ◽

Vol 156 (2) ◽

pp. 285-293 ◽

Cited By ~ 43

Author(s):

S. L. Zunt ◽

L. V. Burton ◽

L. I. Goldblatt ◽

E. E. Dobbins ◽

M. Srinivasan

Keyword(s):

Tumour Necrosis Factor ◽

Tumour Necrosis ◽

Human Saliva ◽

Tumour Necrosis Factor Α ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Factor Α ◽

Necrosis Factor

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Exacerbated Imiquimod-Induced Psoriasis-Like Skin Inflammation in IRF5-Deficient Mice

International Journal of Molecular Sciences ◽

10.3390/ijms21103681 ◽

2020 ◽

Vol 21 (10) ◽

pp. 3681

Author(s):

Momoko Nakao ◽

Tomomitsu Miyagaki ◽

Makoto Sugaya ◽

Shinichi Sato

Keyword(s):

Critical Role ◽

Skin Inflammation ◽

Interferon Α ◽

Toll Like Receptor ◽

Adaptive Immune ◽

Th17 Cytokines ◽

Factor Α ◽

Deficient Mice ◽

Necrosis Factor

Interferon regulatory factors (IRFs) play diverse roles in the regulation of the innate and adaptive immune responses in various diseases. In psoriasis, IRF2 is known to be involved in pathogenesis, while studies on other IRFs are limited. In this study, we investigated the role of IRF5 in psoriasis using imiquimod-induced psoriasis-like dermatitis. Although IRF5 is known to play a critical role in the induction of proinflammatory cytokines by immune cells, such as dendritic cells (DCs), macrophages, and monocytes, IRF5 deficiency unexpectedly exacerbated psoriasiform skin inflammation. The interferon-α and tumor necrosis factor-α mRNA expression levels were decreased, while levels of Th17 cytokines including IL-17, IL-22, and IL-23 were increased in IRF5-deficient mice. Furthermore, IL-23 expression in DCs from IRF5-deficient mice was upregulated both in steady state and after toll-like receptor 7/8 agonist stimulation. Importantly, the expression of IRF4, which is also important for the IL-23 production in DCs, was augmented in DCs from IRF5-deficient mice. Taken together, our results suggest that IRF5 deficiency induces the upregulation of IRF4 in DCs followed by augmented IL-23 production, resulting in the amplification of Th17 responses and the exacerbation of imiquimod-induced psoriasis-like skin inflammation. The regulation of IRF4 or IRF5 expression may be a novel therapeutic approach to psoriasis.

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