Background: Atopic dermatitis (AD) is a chronic skin inflammatory disease characterized by disequilibrium between Th1/Th2 lymphocytes. Helicobacter pylori neutrophil-activating protein (HP-NAP) has been reported that it has the potential immunomodulatory effect able to regulate the Th1/Th2 balance.
Objective: This study aimed to investigate the therapeutic effect of HP-NAP in AD mice model.
Methods: The model of AD was built with oxazolone (OXA) in BALB/c mice, then HP-NAP was used to treat AD by intraperitoneal injection. Ear thickness was measured by a digital thickness gauge. The ears tissues were collected and subjected to hematoxylin-eosin (H&E) and toluidine blue (TB) staining. The mRNA expression levels of inflammatory cytokines (IL-1β, IL-5, IL-6, and TNF-α) in ear tissue were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The secretion of IgE, IL-4, and IFN-γ was measured by enzyme-linked immunosorbent assay (ELISA).
Results: Treatment with HP-NAP successfully alleviated the symptoms of AD, such as erythema, horny substance, and swelling. The infiltration of lymphocytes and mast cells were significantly reduced following HP-NAP therapy. The secretion of IgE and IL-4 was significantly attenuated following treatment with HP-NAP. Additionally, HP-NAP observably downregulated inflammatory cytokine expression (e.g. IL-1β, IL-5, IL-6, and TNF-α) in ear tissues.
Conclusions and clinical relevance: Taken together, our results showed that HP-NAP possessed the potential to be a novel immunomodulatory candidate drug against AD.
Keywords: Atopic dermatitis; HP-NAP; IgE; Th1/Th2 balance; immunomodulation.