Local Receptor-interacting Protein Kinase 2 inhibition mitigates HDM-induced asthma

House dust mite (HDM) is the most frequent trigger of allergic asthma with innate and adaptive immune mechanisms playing critical roles in outcomes. We recently identified the NOD1/RIPK2 signalling pathway as a relevant contributor to murine HDM-induced asthma. This study aimed to evaluate the effectiveness of a pharmacological RIPK2 inhibitor administered locally as a preventive and therapeutic approach using an HDM-induced asthma model in Wild-type (WT) and humanized (h)NOD1 mice harbouring an asthma associated risk allele, and its relevance using airway liquid interface (ALI) epithelial cultures from asthmatics. A RIPK2 inhibitor was administered intra-nasally either preventively or therapeutically in a murine HDM-induced asthma model. Airway hyperresponsiveness (AHR), bronchoalveolar lavage composition, cytokine/chemokines expression and mucus production were evaluated, as well as the effect of the inhibitor on precision-cut lung slices (PCLS). Furthermore, the inhibitor was tested on ALI cultures from asthmatics and controls. While local preventive administration of the RIPK2 inhibitor reduced AHR, eosinophilia, mucus production, Th2 cytokines and IL-33 in WT mice, its therapeutic administration failed to reduce the above parameters, except IL-33. By contrast, therapeutic RIPK2 inhibition mitigated all asthma features in hNOD1 mice. Results of PCLS emphasized an early role of TSLP and IL-33 in the NOD1-dependent response to HDM, and a late effect of NOD1 signalling on IL-13 effector response. RIPK2 inhibitor down-regulated TSLP and chemokines in HDM-stimulated ALI epithelial cultures from asthma patients. These data support that local interference of the NOD1 signalling pathway through RIPK2 inhibition may represent a new therapeutic approach in HDM-induced asthma.