In vitro effects of CpG oligodeoxynucleotides delivered by gelatin nanoparticles on canine peripheral blood mononuclear cells of atopic and healthy dogs - a pilot study

Background Cytosine‐phosphate‐guanine (CpG) oligodeoxynucleotides offer a novel promising immunotherapeutic approach for atopic dermatitis (AD) both in humans and animals. Gelatin nanoparticles (GNP) enhance and prolong CpG‐associated immunomodulatory effects and minimize adverse effects both in vitro and in vivo. Information about the effects of this combination in dogs is lacking. Hypothesis/Objectives The aim of this study was to evaluate immunological effects of CpG coupled to GNP on canine peripheral blood mononuclear cells (PBMCs) in vitro. Animals Eight dogs with AD, diagnosed by standard criteria and with a concurrent immediate hypersensitivity to house dust mites were included. Control samples were taken from eight healthy, age‐matched control dogs without history or evidence of cutaneous or systemic illness. Methods Peripheral blood mononuclear cells of healthy and allergic dogs were incubated with CpG‐GNP and the uptake of CpG‐GNP was demonstrated using confocal laser scanning microscopy. Cell culture supernatant concentrations of interferon gamma (IFN‐γ), interleukin (IL)‐4, IL‐6 and IL‐10 were measured by Canine Cytokine Milliplex. Results No significant changes in IFN‐γ and IL‐4 were found when comparing PBMCs incubated with CpG and CpG‐GNP with the negative controls in atopic and healthy dogs. Interleukin‐6 was not detected in any of the groups. However, a statistically significant increase in IL‐10 concentration was found after 24 h stimulation with CpG‐GNP compared with CpG alone both in atopic and healthy dogs. Conclusions and clinical importance As IL‐10 is considered an immunosuppressive cytokine playing a key role in peripheral tolerance; the reported CpG‐GNP formulation could be a new approach in allergy treatment. Résumé Contexte Les oligodéoxynucléotides cytosine‐phosphate‐guanine (CpG) offrent une nouvelle approche immunothérapeutique prometteuse de la dermatite atopique (AD) à la fois chez l'homme et chez l'animal. Les nanoparticules de gélatine (GNP) améliorent et prolongent les effets immunomodulateurs associés aux CpG et minimisent les effets secondaires in vitro et in vivo. On ne connait aucune information sur les effets de cette combinaison chez le chien. Hypothèses/Objectifs Le but de cette étude était d'évaluer les effets immunologiques de CpG couplé à GNP sur les cellules mononucléées sanguines périphériques (PBMCs) in vitro. Sujets Huit chiens avec AD, diagnostiquée par les critères standards et avec une hypersensibilité