Inhibition of dendritic cell autophagy alleviates the progression of allergic rhinitis by inhibiting Th1/Th2/Th17 immune imbalance and inflammation.

Introduction: Immune imbalance is a fundamental immunological feature of allergic rhinitis (AR). The autophagy in CD11c⁺ dendritic cells (DCs), the strongest antigen-presenting cells, was reported to induce the occurrence of AR by facilitating CD4⁺ T cell immune imbalance and subsequent inflammation. Our study was designed to confirm that inhibition of DC autophagy can alleviate the progression of AR by inhibiting the T cell immune imbalance.

Methods: The AR mouse model was established by using ovalbumin (OVA). OVA-induced mouse models were then injected intraperitoneally with the autophagy inhibitor Baf-A1. Levels of OVA-specific IgE, PGD2, ECP, LTC4, and Th1/Th2/Th17 cell-related cytokines in serum or nasal lavage fluid (NLF) were examined using the corresponding commercial ELISA kits. Morphological changes in the nasal mucosa were observed by HE staining. Nasal mucosa tissues were collected for western blotting to assess the expression of autophagy markers (LC3, P62, and Beclin 1) in each group of mice.

Results: Baf-A1 treatment alleviated the allergic symptoms, mitigated inflammatory immune cell infiltration in the nasal mucosa, decreased IgE, LTC4, ECP, and PGD2 levels in both serum and NLF, impaired CD11c⁺ DC autophagy, and restored Th1/Th2/Th17 cytokine imbalance in OVA-induced AR mice. Furthermore, Baf-A1 treatment also reversed the immune imbalance of CD4⁺ T cell subtypes and attenuated Th1/Th2/Th17 cytokine imbalance in vitro.

Conclusion: Inhibition of CD11c⁺ DC autophagy suppressed the immune imbalance of CD4⁺ T cell subsets and attenuated the subsequent inflammatory response, thereby ameliorating the progression of AR.