Steroid Treatment Reduces Allergic Airway Inflammation and Does Not Alter the Increased Numbers of Dendritic Cells and Calcitonin Gene-Related Peptide-Expressing Neurons in Airway Sensory Ganglia

The impact of influenza pulmonary infection and inflammation on vagal bronchopulmonary sensory neurons

Influenza A virus (IAV) is rapidly detected in the airways by the immune system, with resident parenchymal cells and leukocytes orchestrating viral sensing and the induction of antiviral inflammatory responses. The airways are innervated by heterogeneous populations of vagal sensory neurons which also play an important role in pulmonary defense. How these neurons respond to IAV respiratory infection remains unclear. Here, we use a murine model to provide the first evidence that vagal sensory neurons undergo significant transcriptional changes following a respiratory IAV infection. RNA sequencing on vagal sensory ganglia showed that IAV infection induced the expression of many genes associated with an antiviral and pro-inflammatory response and this was accompanied by a significant increase in inflammatory cell recruitment into the vagal ganglia. Assessment of gene expression in single-vagal sensory neurons confirmed that IAV infection induced a neuronal inflammatory phenotype, which was most prominent in bronchopulmonary neurons, and also evident in some neurons innervating other organs. The altered transcriptome could be mimicked by intranasal treatment with cytokines and the lung homogenates of infected mice, in the absence of infectious virus. These data argue that IAV pulmonary infection and subsequent inflammation induces vagal sensory ganglia neuroinflammation and this may have important implications for IAV-induced morbidity.

Naso-ocular neuropeptide interactions in allergic rhinoconjunctivitis, rhinitis, and conjunctivitis

Background

Ocular as well as nasal symptoms contribute to allergic response but remain poorly characterized. The aim of this study was to analyze the levels of substance P (SP), vasoactive intestinal peptide (VIP), and calcitonin gene-related peptide (CGRP) in tears and nasal secretions of patients with allergic rhinoconjunctivitis (ARC), allergic rhinitis, and allergic conjunctivitis, while exploring possible mechanisms of naso-ocular interactions.

Methods

A total of 21 patients with ARC, 17 with allergic rhinitis, 13 with allergic conjunctivitis, and 15 healthy controls were enrolled in the study. Nasal secretions and tears were collected. Patient demographics and clinical characteristics were recorded and levels of substance P, VIP, and CGRP were measured.

Results

SP levels in nasal secretions and tears were significantly higher in the ARC, AR, and AC groups. Similar results were obtained for VIP levels. CGRP levels in tears were also significantly higher in the 3 patient groups. The level of SP was significantly higher in the nasal secretions than in the tears of the ARC, AR, and AC patient groups. The level of VIP was significantly higher in the nasal secretions than in the tears in the ARC and AR groups. The level of CGRP was significantly higher in the nasal secretions than in the tears in the ARC and AC groups. Finally, both of the nasal and tear levels of SP and VIP but not CGRP were positively correlated with the visual analog scale (VAS) score in the patients with ARC.

Conclusion

The results of this study suggested that SP, VIP, and CGRP play important roles in the mechanism of ARC and that nasal neurotransmitters and neuropeptides might have more important roles than those of ocular origin.

Majie cataplasm provides a shield against asthmatic punch from the neuroimmune system

Asthma poses a threat to human health, and its pathogenesis is closely related to the neuroimmune system. Majie cataplasm can not only regulate the immune system but also the nervous system in asthma patients for its components. We speculate that Majie cataplasm may relieve asthmatic patients with sensitivity to hormone or not by regulating the body's neuroimmune system.

Methods

In this experiment, a mouse model of asthma was well established by ovalbumin. The lung function of animals was examined and pathological changes in the lung tissue were assessed by hematoxylin-eosin staining. Serum immunoglobulin E (IgE), calcitonin gene-related peptide (CGRP) and neurokinin A (NKA) were measured by ELISA. The location of CGRP, CD3 and neutrophil in lung tissue and their expressions were detected by immunofluorescence staining. In addition, contents of CGRP mRNA, Substance P (SP) mRNA, interleukin (IL)-17 mRNA and interleukin(IL)-13 mRNA were detected by quantitative polymerase chain reaction.

Results

Compared with the asthma model group, Majie cataplasm and dexamethasone can not only equivalently relieve airway hyperresponsiveness, but also make the content of serum IgE reduced. In addition, they can lower the content of serum CGRP and NKA after OVA stimulation, and this effect was more obvious for Majie cataplasm. Our results also showed that Majie Cataplasm and dexamethasone could inhibit the secretion of CGRP and the infiltration of T lymphocytes together with neutrophils in lung tissue and reduce expressions of CGRP mRNA, SP mRNA, IL-17 mRNA and IL-13 mRNA in lung tissue.

Conclusion

Majie cataplasm effectively relieves expressions of neuropeptides such as CGRP, reduces the infiltration of immune cells in lung tissue, regulates the body's neuroimmune system, and has a therapeutic potential for both Th2 asthma and neutrophilic asthma.

Decreased Migration of Dendritic Cells into the Jugular-Nodose Ganglia by the CXCL12 Neutraligand Chalcone 4 in Ovalbumin-Sensitized Asthmatic Mice

OBJECTIVE

The chemokine CXCL12 interacting with the CXC receptor 4 (CXCR4) has been reported to play a role in the development and progression of bronchial asthma, but its mechanism of action is still unknown. The objective of this study was to assess the effect of the CXCL12 neutraligand chalcone 4 on the migration of dendritic cells (DCs) in a murine model of allergic airway inflammation.

METHODS

A 21-day ovalbumin (OVA)-induced allergic-airway TH2 inflammation model in BALB/c mice was used. Four groups were sensitized with OVA adsorbed on alum and challenged either with OVA or saline for 4 days. Mice were treated intranasally with chalcone 4 (300 nmol/kg body weight) or solvent 2 h before each OVA or saline challenge; 24 h after the last challenge, CD11c+F4/80- DCs were counted in the bronchoalveolar lavage. Jugular-nodose ganglion complex (JNC) sections were sampled, and for immunofluorescence staining, cryocut sections were prepared. MHC II+F4/80- DCs as well as calcitonin gene-related peptide (CGRP)- and substance P (SP)-positive neuronal cell bodies were analyzed.

RESULTS

In OVA-challenged mice, chalcone 4 caused a significantly decreased DC/neuron ratio in the JNC from 51.7% in solvent-treated to 32.6% in chalcone 4-treated mice. In parallel, chalcone 4 also decreased the DC population in BALF from 11.5 × 103 cells in solvent to 4.5 × 103 cells in chalcone 4-treated mice. By contrast, chalcone 4 had no effect on the expression of the neuropeptides CGRP and SP in JNC.

CONCLUSION

This study reported the CXCL12 neutraligand chalcone 4 to affect DC infiltration into the airways and airway ganglia as well as to decrease airway eosinophilic inflammation and, therefore, validated CXCL12 as a new target in allergic disease models of asthma.