R848, a Toll-like receptors 7 and 8 agonist, a potential therapy for allergic rhinitis patients.

Background/purpose(s): There is a growing interest in the targeting of Toll-like receptors (TLRs) for the treatment of allergic diseases. TLRs7/8 ligands are future candidates of therapeutic value in allergic rhinitis (AR). This study focus on TLRs7/8 ligand; resiquimod (R848) as an adjuvant to immunotherapy (IT) in AR patient.

Methods: Peripheral blood mononuclear cells (PBMCs) were obtained from atopic donors and non atopic donors. PBMCs were cultured in the absence and presence of date palm pollen allergen (Phoenix dactylifera; Pho d) and/or R848. Interleukin-4 (IL-4), IL-10, IL-13 and interferon gamma (IFN-γ) were measured in the culture supernatants.

Results: R848 was able to significantly increase the anti-inflammatory response in atopic donors more than non atopic donors. Nevertheless, the combination of both; R848 and Pho d provides inferior stimulus as compared to R848 alone in both atopic and non atopic donors.

Conclusion: Invitro treatment of PBMCs with R484 hijacks the pro inflammatory immune process triggered by TLRs7/8 to mediate anti-inflammatory response. This may provide a conception about the activity and efficacy of TLRs7/8 ligands in AR and open the gate for them to be applied in clinically in humans.