Effect of an Antagonistic Peptide of CCR5 on the Expression of Autophagy-related Genes and β-Arrestin 2 in Lung Tissues of Asthmatic Mice

Changes of allergic inflammation and immunological parameters after Alt a 1 and A. alternata immunotherapy in mice

Background

The efficacy of allergen-specific subcutaneousimmunotherapy (SCIT) with Alt a 1 of the fungus A. alternata is still unknown. Yet, few studies compare the therapeutic effects and immunological mechanisms of Alt a 1 and A. alternata extracts. We aim to explore and compare the changes in allergic inflammation and immunological mechanisms of Alt a 1 and A. alternata in mice.

Methods

Female BALB/c mice administrated recombinant Alt a 1 (rAlt a 1), native Alt a 1 (nAlt a 1), and A. alternata. Lung histology, airway hyper-reactivity (AHR), bronchoalveolar lavage fluid (BALF) cytokine levels, serum immunoglobulin responses, the expression of Bcl-6, the percentages of T follicular helper cells (Tfh), cytokine-related Tfh subtypes, regulatory B cells (Breg), and IL-10+ Breg cells were detected.

Results

High-purity nAlt 1 protein was obtained. SCIT with Alt a 1 and Alternaria decreased airway and lung inflammation, including improvement of lung pathology, lower levels of AHR, reduction of total cell numbers, and IL-4 and IL-13 levels in BALF. Furthermore, Alt a 1-SCIT effectively suppressed the IgE responses, elevated IgG titers, and was superior in decreasing the expression of Bcl-6. Additionally, Alternaria-SCIT significantly decreased the expression of Tfh cells, L-4+ Tfh, and IL-5+ Tfh cells in the spleen, whereas Alt a 1 showed superior therapeutic effects in the lymph node. IL-13+ Tfh cells in these two treatment groups not being significant. IL-17A+ Tfh cells were alleviated most effectively after A. alternata-SCIT in both the spleen and lymph node. Intriguingly, IL-10+ Breg cells decreased remarkably in response to SCIT with rAlt a 1.

Conclusions

Treatments with Alt a 1 and A. alternata extracts had beneficial effects on allergic inflammation. Alt a 1-SCIT resulted in prominent improvement in the immunoglobulin responses, Bcl-6, and IL-10+ Breg cells. Alternaria-SCIT was more likely to suppress the expression of Tfh and cytokine-related Tfh subtypes.

Relationship Between the Expression of LC3 (Microtubule-Associated Protein 1A/1B-Light Chain 3) in Nasal Mucosa and Serum IL-5 and IL-4 Concentrations in Allergic Rhinitis Mice

Objective

To investigate the expression and correlation of autophagy-related microtubule-associated protein 1 light chain 3 beta LC3 and interleukin-5 IL-5 in allergic rhinitis AR.

Methods

Fifty-six 7-week-old BALC/C mice were randomly divided into experimental group (n = 56) and control group (n = 8). The experimental group used Dermatophagoides farinae (Der f) for AR modeling, and control group used PBS solution. As the experimental group sampled at 6 time points, and 8 mice were sacrificed each time, while the control group was sacrificed 24 hours after the last dose. The contents of serum IL-4, IL-5, and dust mite specific IgE HDM-sIgE in mice were detected by enzyme-linked immunosorbent assay ELISA, and the morphological changes of nasal mucosa were detected by a hematoxylin-eosin H&E staining. The expression of LC3 in mouse nasal mucosa was detected by immunohistochemical staining. Spearman correlation coefficient was used to assess the relationship between LC3 and IL-5 levels.

Results

In AR mice modelled with dust mites, the serum levels of IL-4 and HDM-sIgE increased gradually, and the serum IL-5 concentration had a peak at the early intraperitoneal administration stage similar to that at the end of modelling. The LC3 level in nasal mucosa of AR mice modelled with dust mites increased gradually in the early stages, but stabilized in the later stages. The expression of LC3 level in nasal mucosa was a positively correlated ration between serum IL-5 level in AR mice.

Conclusion

In the early stage of AR mice, the level of nasal mucosal autophagy and serum IL-5 levels were significantly increased and correlated, suggesting that nasal mucosal autophagy played a promoting role in the early stage of AR.

Deletion of Arrb2 Down-regulates Autophagy in the Mouse Hippocampus via Akt-mTOR Pathway Activation

The cytoplasmic multifunctional adaptor protein β-arrestin 2 (Arrb2) is involved in the occurrence of various nervous system diseases, such as Alzheimer's disease and Parkinson's disease. Previous laboratory studies have shown that the expression and function of the Arrb2 gene was increased in valproic acid-induced autistic mice models. However, few reports have examined the possible role of Arrb2 in the pathogenesis of autism spectrum disorder. Therefore, Arrb2-deficient (Arrb2^-/-) mice were further studied to uncover the physiological function of Arrb2 in the nervous system. In this study, we found that Arrb2^-/- mice had normal behavioral characteristics compared with wild-type mice. The autophagy marker protein LC3B was decreased in the hippocampus of Arrb2^-/- mice compared to wild-type mice. Western blot analysis revealed that deletion of Arrb2 caused hyperactivation of Akt-mTOR signaling in the hippocampus. In addition, abnormal mitochondrial dysfunction was observed in Arrb2^-/- hippocampal neurons, which was characterized by a reduction in mitochondrial membrane potential and adenosine triphosphate production and an increase in reactive oxygen species levels. Therefore, this study elucidates the interaction between Arrb2 and the Akt-mTOR signaling pathway and provides insights into the role of Arrb2 in hippocampal neuron autophagy.

Identification of potential key autophagy-related genes in asthma with bioinformatics approaches

OBJECTIVES

Asthma is a chronic respiratory disease characterized by airway remodeling and inflammation. Recent studies have demonstrated that multiple autophagy-related genes are involved in the pathogenesis of asthma. However, the roles of many of these autophagy-related genes in asthma remain unclear, particularly with regard to the diagnosis of asthma.

METHODS

In this study, autophagy-related differentially expressed genes (DEGs) in asthma were identified by bioinformatics analysis of the GSE76262 datasets. Hub genes were screened by protein-protein interaction (PPI) network and module analyses. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were used to explore potential signaling pathways. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of autophagy-related biomarkers in asthma.

RESULTS

A total of 17 autophagy-related DEGs were identified, most of which were involved in autophagy and protein processing in the endoplasmic reticulum signaling pathway. ROC curve analysis demonstrated that the hub genes (HIF1A, ERN1, and DNAJB1) identified from the PPI network exhibited good performance in the diagnosis of asthma. The GSE137268 and GSE43696 databases were used to verify the expression of 17 autophagy-related DEGs in asthma. Interestingly, ERN1 was an overlapping gene defined by the intersection of hub autophagy-related DEGs and key modules (including HIF1A, ERN1, and DNAJB1). We also analyzed the interaction between miRNAs and mRNAs for 14 autophagy-related DEGs with an area under the curve > 0.7. The identified genes were involved in the glypican, interferon-gamma, and plasma membrane estrogen receptor signaling pathways.

CONCLUSIONS

The results of this study indicate that specific signaling pathways and autophagy-related DEGs are potential diagnostic biomarkers related to the inception and progression of asthma.

Immunotherapy With Recombinant Alt a 1 Suppresses Allergic Asthma and Influences T Follicular Cells and Regulatory B Cells in Mice

Background

Alternaria is a major source of asthma-inducing allergens. Allergen-specific immunotherapy improves the progression of allergic asthma. The current treatment is based on crude Alternaria extracts. Alt a 1 is the predominant allergen in Alternaria. However, the treatment efficacy of recombinant Alt a 1 (rAlt a 1) in an asthmatic animal model and its influence on Tfh and Breg cells are unknown.

Objective

To explore the therapeutic treatment effects of rAlt a 1 on the progress of an asthmatic mouse model and its effect on Tfh and Breg cells.

Methods

We synthesized and purified rAlt a 1. Alternaria-sensitized and challenged mice received subcutaneous immunotherapy (SCIT) with four different rAlt a 1 dosages (5, 50, 100, and 150 µg) or PBS only. Finally, lung and airway inflammation, mouse mast cell protease 1 (MMCP-1), serum immunoglobulin responses, Tfh and Breg cell levels, and the correlation between asthmatic features (inflammation grades and IL-4 and IL-10 levels) and these two cell types were measured after Alternaria rechallenge.

Results

High purity and allergenic potency of rAlt a 1 protein were obtained. Following treatment with four different rAlt a 1 dosages, both lung and airway inflammation ameliorated, including lung pathology, serum MMCP-1 levels, inflammatory cell numbers, and cytokine levels in bronchoalveolar lavage fluid (BALF). Additionally, rAlt a 1-SCIT increased the expression of Alternaria-sIgG1, rAlt a 1-sIgG1, rAlt a 1-sIgG2a, and rAlt a 1-sIgG2b in serum. Moreover, the number and percentage of CXCR5⁺PD-1⁺Tfh cells were increased in the PC control, while they decreased in the rAlt a 1-SCIT groups. Meanwhile, the absolute numbers and proportions of Breg cells were evaluated after administration of rAlt a 1. A positive correlation was observed between CXCR5⁺PD-1⁺Tfh cells and inflammation grades (r = 0.50, p = 0.01), as well as a slightly strong positive relationship with IL-4 (r = 0.55, p = 0.005) and IL-10 (r = 0.58, p = 0.003) levels; Breg cells showed an opposite correlation with the grades of inflammation (r = -0.68, p = 0.0003), along with a negative correlation to IL-4 (r = -0.61, p = 0.001) and IL-10 (r = -0.53, p = 0.008) levels.

Conclusions

We verified that treatment with rAlt a 1 can alleviate asthma progression and further have a regulatory effect on Tfh and Breg cells in an Alternaria-induced asthmatic mouse model.

The Interplay of HIV and Autophagy in Early Infection

HIV/AIDS is still a global threat despite the notable efforts made by the scientific and health communities to understand viral infection, to design new drugs or to improve existing ones, as well as to develop advanced therapies and vaccine designs for functional cure and viral eradication. The identification and analysis of HIV-1 positive individuals that naturally control viral replication in the absence of antiretroviral treatment has provided clues about cellular processes that could interact with viral proteins and RNA and define subsequent viral replication and clinical progression. This is the case of autophagy, a degradative process that not only maintains cell homeostasis by recycling misfolded/old cellular elements to obtain nutrients, but is also relevant in the innate and adaptive immunity against viruses, such as HIV-1. Several studies suggest that early steps of HIV-1 infection, such as virus binding to CD4 or membrane fusion, allow the virus to modulate autophagy pathways preparing cells to be permissive for viral infection. Confirming this interplay, strategies based on autophagy modulation are able to inhibit early steps of HIV-1 infection. Moreover, autophagy dysregulation in late steps of the HIV-1 replication cycle may promote autophagic cell-death of CD4⁺ T cells or control of HIV-1 latency, likely contributing to disease progression and HIV persistence in infected individuals. In this scenario, understanding the molecular mechanisms underlying HIV/autophagy interplay may contribute to the development of new strategies to control HIV-1 replication. Therefore, the aim of this review is to summarize the knowledge of the interplay between autophagy and the early events of HIV-1 infection, and how autophagy modulation could impair or benefit HIV-1 infection and persistence, impacting viral pathogenesis, immune control of viral replication, and clinical progression of HIV-1 infected patients.