The Immunomodulatory Effect of Toll-like Receptors 7/8 ligand (tlrs7/8) in Allergic Rhinitis Patients

there is a growing interest in the targeting of Toll-like receptors (TLRs) for the treatment of allergic diseases. Several new compounds are now undergoing preclinical and clinical evaluation. TLRs7/8 ligands are promising candidate drugs for the treatment of allergic rhinitis (AR). Here we focus on TLRs7/8 ligand; resiquimod (R848) as an adjuvant to immunotherapy (IT) in AR patients.Objectives: We are trying to assess the in vitro capacity of R848 as an immune-modulator on the pro-inflammatory cytokines; interleukin (IL) 4, IL-13 and anti-inflammatory cytokines; IL-10 and IFN-γ.Material and Methods: Peripheral blood mononuclear cells (PBMCs) were obtained from 20 non atopic donors, 10 non IT atopic donors and 10 IT atopic donors. PBMCs were cultured in the absence and presence of date palm pollen allergen (Phoenix dactylifera; Pho d) and/ or R848. IL4, IL-10, IL-13 and IFN-γ were measured in the culture supernatants.Main Results: R484 was able alone to significantly increase the anti-inflammatory response in atopic donors however, the combination of both provides inferior stimulus when compared to R848 alone.Conclusion: In vitro treatment of PBMCs with R484 hijacks the pro-inflammatory immune process triggered by TLRs7/8 to mediate anti-inflammatory response. This provides important insight into the efficacy and mode of action of TLRs7/8 ligands in AR and paves the way for their clinical application in humans.Key words: Toll-like receptors, Allergic rhinitis, R848, Phoenix dactylifera..