T-Helper Type 2 Cells Direct Antigen-Induced Eosinophilic Skin Inflammation in Mice

Plasma Levels of CXCL9 and MCP-3 are Increased in Asthma-COPD Overlap (ACO) Patients

Purpose

Asthma and chronic obstructive pulmonary disease overlap patients (ACO) have more exacerbations and a worse prognosis than pure asthma or COPD, and it is of great interest to identify differential biomarkers of ACO. We compared blood eosinophil counts, plasma IgE and protein levels among patients with asthma, ACO, COPD, and healthy subjects to identify those associated with ACO.

Patients and Methods

397 adults (age 40-90 years) were recruited from two Colombian cities: asthma (n=123), COPD (n=100), ACO (n=74) and healthy control (HC, n=100). Plasma protein levels were measured using the Proximity Extension Assay (Olink Proteomics).

Results

There were no differences in blood eosinophil counts between the patient groups. Total and specified IgE levels were higher in patients with ACO than in those with COPD. Ten plasma proteins showed significant differences between the patients with ACO and HC. In patients above 60 years old, CXCL9 discriminates ACO from asthma patients with AUC 0.73 (0.63-0.82, DeLong test p=0.007), and in patients below 60 years old, MCP-3 discriminates ACO from COPD patients with AUC 0.84 (0.62-1.0, DeLong test p=0.006). CUB domain-containing protein 1 (CDCP1) levels (OR, 0.47; p=0.008) and age > 60 years (OR, 0.25; p=0.001) were negatively associated with ACO.

Conclusion

CXCL9 levels could be used to discriminate ACO from asthma patients and MCP-3 to discriminate ACO from COPD. Protein inflammatory signatures in plasma of ACO patients were similar to the COPD group. This study revealed novel biomarkers that may help characterize patients with ACO.

Oral treatment with Rosa multiflora fructus extract modulates mast cells in canine atopic dermatitis

Introduction

Canine atopic dermatitis is a hereditary, often pruritic, and predominantly T-cell-driven inflammatory skin disease involving an interplay between skin barrier abnormalities and allergen sensitization. However, progress in developing therapeutics for companion animals remains slow, with few drugs advancing to Phase II clinical trials to investigate the underlying mechanisms in target animals. While Rosa multiflora fruit extract (RMFE) has been strongly implicated in the improvement of various inflammatory diseases, its effects on canine atopic dermatitis (cAD) and the putative underlying mechanisms remain unclear. In this study, we aimed to evaluate the efficacy of RMFE in the treatment of cAD and explore its underlying mechanisms.

Methods

In this study, RMFE was administered orally (repeatedly for 2 weeks) to ovalbumin (OVA)-induced atopic dermatitis-induced beagles. The effects of RMFE on cAD were assessed through clinical symptom observation and scoring using the canine atopic dermatitis extent and severity index. Additionally, histopathological analysis was performed (hematoxylin and eosin, Masson's trichrome, and toluidine blue). Cluster of differentiation 4-positive immunostaining was also performed, along with cytokine level and messenger ribonucleic acid level analyses of T-helper 2 (Th2) immune and inflammatory response markers in the modeled skin.

Results

RMFE improved the clinical manifestations of cAD, leading to histopathological modulation of inflammation and immune cells. It also altered Th2 effector cytokine levels. Furthermore, RMFE reduced allergic responses in the AD model dogs by reducing mast cell numbers, inhibiting their activation to release inflammatory mediators, and reducing immunoglobulin E (IgE) production.

Discussion

Our results suggest that RMFE can modulate mast cell activation and Th2-dominant immune responses in cAD, helping to reduce AD-induced inflammatory responses.

The essential oils from Asarum sieboldii Miq. Alleviate allergic rhinitis by regulating tight junction and inflammation; Network analysis and preclinical validation

ETHNOPHARMACOLOGICAL RELEVANCE

Essential oils from herbs, including those from Asarum sieboldii Miq., are readily absorbed through mucous membranes, explaining their widespread use in inhalation formulations. Asarum sieboldii Miq. has a long history of traditional use for various medicinal purposes, attributed to its anti-inflammatory, antiallergic, and antioxidant properties. Despite research on Asarum sieboldii Miq. for allergic inflammation in respiratory diseases, detailed mechanistic studies are still lacking.

AIM OF THE STUDY

We utilized bioinformatics and network pharmacology to identify the effectiveness of Asarum sieboldii Miq. in treating allergic rhinitis (AR). Our aim is to elucidate the potential therapeutic effects of essential oil derived from Asarum sieboldii Miq. (ASO), which is recognized for its diverse pharmacological properties, on AR.

MATERIALS AND METHODS

Common genes associated with the active compounds of ASO and AR were utilized to construct a related network and predict their mode of action. AR was induced in BALB/c mice by exposing them to ovalbumin (OVA) and particulate matter 10 (PM10; airborne particles <10 μm). With induction, aerosolized ASO (0.0002% and 0.02%) were administered via nebulizer for 5 min per day, three times a week for 7 weeks. Mice were examined for histopathological changes in the nasal tissue, nasal epithelial inflammation, the production of allergen-specific cytokine response in vitro and in vivo.

RESULTS

The common genes of ASO and AR were predicted to include 'Tight junction', 'Apoptosis', and 'TGF-beta signaling', which are the main pathways of pathogenesis in AR. Consistent with network prediction, nebulized ASO treatment effectively improved the expression of tight junction-related factors, zonula occludens-1, claudin-1, occludin and junction adhesion molecule A, in OVA + PM10 induced mice. Additionally, it reduced hyperplasia of nasal epithelial thickness, goblet cell counts, and inflammatory cell infiltration (eosinophils, neutrophils, macrophages, and lymphocytes) in nasal lavage fluid, while also alleviating allergic symptoms such as sneezing, rubbing, and serum IgE level when compared to the AR-induced group. The levels of mRNA and protein expression related to tight junctions were restored to normal levels by ASO, as confirmed in immunofluorescence analysis in nasal epithelial cells RPMI2650. Furthermore, treatment of ASO on PM10-treated nasal epithelial cells significantly reduced ROS production, recovered mitochondria membrane potential, and inhibition of the production of proinflammatory cytokines (TNF-α, IL-4, and IL-13) and inflammatory mediators linked to the MAPK/NF-κB signaling pathways.

CONCLUSION

Intranasal nebulization of ASO improves TJs and alleviates allergic nasal inflammation in AR. It supports the potential pharmaceutical application of ASO treatment for AR.

Differential resistance to nematode infection is associated with the genotype- and age-dependent pace of intestinal T cell homing

The resistance of inbred mice to nematode infections varies depending on the extent of protective Th2 responses. Here, we compared two mouse lines differing in resistance to infection with the enteric nematode Heligmosomoides polygyrus bakeri despite the similar instruction of GATA-3+ T effector cells. Resistant BALB/c mice rapidly recruited high numbers of Th2 cells to the gut within the 1-week time frame required for larval development in the intestinal submucosa. C57BL/6 mice failed in the optimal control of early nematode fitness, with mucosal Th2 response peaking after 2 weeks when the larvae had left the tissue and relocated to the gut lumen as adult worms. The faster homing of Th2 cells to the gut of BALB/c mice is related to the extensive expression of the chemokine receptor CCR9 in GATA-3+ cells and higher frequencies of aldehyde dehydrogenase expressing dendritic cells present in mesenteric lymph nodes. Furthermore, nematode-infected older BALB/c mice displayed impaired resistance due to delayed mucosal homing of effector cells, which synergized with more numerous Th2/1 hybrid cells acting as IFN-γ-dependent confounders of type 2 responses. Hence, the distinct kinetics of effector cell recruitment to the infected gut and the quality of GATA-3+ T cell responses contribute to the genotype- and age-dependent resistance to intestinal nematode infections.

Eosinophilic inflammation: a key player in COPD pathogenesis and progression

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) remains a significant public health challenge due to its high morbidity and mortality rates. Emerging research has identified eosinophilic inflammation as a crucial factor in the pathogenesis and exacerbation of COPD, warranting a detailed exploration of its underlying mechanisms and therapeutic implications.

OBJECTIVE

This review aims to elucidate the role of eosinophils in COPD, focusing on their contribution to airway remodeling, exacerbation frequency, and the inflammatory cascade.

METHODS

We conducted a comprehensive literature review of recent studies that discuss the pathophysiological role of eosinophils in COPD and the clinical outcomes associated with modulating eosinophilic activity.

RESULTS

Eosinophils contribute to COPD progression by releasing cytotoxic proteins and cytokines that intensify the inflammatory response and airway alterations. Targeting specific eosinophil-related cytokines with monoclonal antibodies or receptor antagonists may potentially reduce eosinophil counts, mitigate exacerbations, and improve patient outcomes.

CONCLUSION

Understanding eosinophilic involvement in COPD can facilitate the development of precision medicine approaches, offering more tailored and effective treatment options. Future research should continue to focus on the integration of eosinophil biomarkers in clinical practice to enhance therapeutic decisions and management strategies for COPD patients.

Role of CD4+ T Cells in Allergic Airway Diseases: Learning from Murine Models

The essential contribution of CD4⁺ T cells in allergic airway diseases has been demonstrated, especially by using various murine models of antigen-induced airway inflammation. In addition to antigen-immunized mouse models employing mast cell-deficient mice and CD4⁺ T cell-depleting procedure, antigen-specific CD4⁺ T cell transfer models have revealed the possible development of allergic inflammation solely dependent on CD4⁺ T cells. Regardless of the classical Th1/Th2 theory, various helper T cell subsets have the potential to induce different types of allergic inflammation. T cell receptor (TCR)-transgenic (Tg) mice have been used for investigating T cell-mediated immune responses. Besides, we have recently generated cloned mice from antigen-specific CD4⁺ T cells through somatic cell nuclear transfer. In contrast to TCR-Tg mice that express artificially introduced TCR, the cloned mice express endogenously regulated antigen-specific TCR. Upon antigen exposure, the mite antigen-reactive T cell-cloned mice displayed strong airway inflammation accompanied by bronchial hyperresponsiveness in a short time period. Antigen-specific CD4⁺ T cell-cloned mice are expected to be useful for investigating the detailed role of CD4⁺ T cells in various allergic diseases and for evaluating novel anti-allergic drugs.

Lysophosphatidylcholines inhibit human eosinophil activation and suppress eosinophil migration in vivo

Eosinophils are important multifaceted effector cells involved in allergic inflammation. Following allergen challenge, eosinophils and other immune cells release secreted phospholipases, generating lysophosphatidylcholines (LPCs). LPCs are potent lipid mediators, and serum levels of LPCs associate with asthma severity, suggesting a regulatory activity of LPCs in asthma development. As of yet, the direct effects of LPCs on eosinophils remain unclear. In the present study, we tested the effects of the major LPC species (16:0, 18:0 and 18:1) on eosinophils isolated from healthy human donors. Addition of saturated LPCs in the presence of albumin rapidly disrupted cholesterol-rich nanodomains on eosinophil cell membranes and suppressed multiple eosinophil effector responses, such as CD11b upregulation, degranulation, chemotaxis, and downstream signaling. Furthermore, we demonstrate in a mouse model of allergic cell recruitment, that LPC treatment markedly reduces immune cell infiltration into the lungs. Our observations suggest a strong modulatory activity of LPCs in the regulation of eosinophilic inflammation in vitro and in vivo.

Effects and mechanism of action of Huang-Lian-Jie-Du-Tang in atopic dermatitis-like skin dysfunction in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD), a disorder prevalent during childhood and adulthood, seriously affects the patient's quality of life. Although Huang-Lian-Jie-Du-Tang (HLJDT) has shown anti-inflammatory effects in previous studies, its effects and mechanism of action underlying AD disorder are still largely unknown.

OBJECTIVE

This study explored the anti-inflammatory and immunomodulatory effects of HLJDT on the AD-like dermal disorder, induced in vitro by lipopolysaccharide (LPS)-triggered inflammation, and in vivo by 2,4-dinitrochlorobenzene (DNCB).

MATERIALS AND METHODS

In vivo HLJDT effects were investigated by determining the severity of dermatitis, which consisted of observing signs of skin lesions, visually and through haematoxylin and eosin (HE) staining, in mouse ears and dorsal skin, measuring serum levels of interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, interferon (IFN)-γ, the tumour necrosis factor (TNF)-α, and determining the splenic index, number of splenic CD4⁺/CD8⁺ T-lymphocytes, as well as the phosphorylation levels of mitogen-activated protein kinases (including MAPKs-p38, ERK, and JNK), IκB-α, and nuclear factor kappa B (NF-κB) (p65) within dermal lesions. Morphological changes in LPS-induced inflammation were observed under a microscope, and ELISA and qPCR assays were used to measure IL-1α, IL-1β, IL-6, and TNF-α expression levels. The protein expression levels of P-ERK/ERK, P-p38/p38, P-JNK/JNK, P-IKβ-α, and P-p65 were measured through western blotting. Additionally, p65 expression was assessed by immunofluorescence, and LPS binding to RAW264.7 cell membrane was studied with laser confocal microscopy.

RESULTS

HLJDT could remarkably mitigate DNCB-induced AD-like lesion symptoms, alleviating inflammatory mediator infiltration in mouse ears and dorsal skin tissue, down-regulating serum expression levels of IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IFN-γ, and TNF-α, normalising the splenic CD4⁺/CD8⁺ T-lymphocyte ratio, and inactivating MAPKs (including p38, ERK, and JNK), IκB-α, and NF-κB (p65) in dorsal skin. Furthermore, HLJDT inhibited LPS-induced differentiation of RAW264.7 cells, as evidenced by the decreased protein and mRNA expression of IL-1α, IL-1β, IL-6, and TNF-α. Additionally, it decreased ERK, p38, JNK, IKβ-α, and p65 phosphorylation levels in the MAPKs/NF-κB pathway, inhibited p65 nuclear translocation, and reduced LPS binding to the RAW264.7 cell membrane.

CONCLUSIONS

HLJDT significantly improved AD-like symptoms via inhibition of the MAPKs/NF-κB pathway. Therefore, administration of HLJDT might be a potential treatment for AD in the clinical setting.