Search Results (130)

Background/Objectives: Exposure to particulate matter (PM) containing bacterial endotoxins triggers inflammation and oxidative stress in the respiratory epithelium. In this study, we investigated chitosan nanoparticle-loaded Cordyceps militaris grown on germinated Rhynchosia nulubilis (GCN) as a potential functional food-derived ingredient against PM- and lipopolysaccharide (LPS)-induced cellular damage in human lung epithelial cells. Methods: This study employed an integrative approach combining GCN analysis with bioinformatics methods using a PM- and LPS-induced pulmonary cellular inflammation model. Gene Expression Omnibus (GEO) transcriptomic datasets and Cytoscape-based network analysis were utilized to identify key hub genes and signaling pathways associated with PM- and LPS-induced pulmonary inflammation, which were subsequently validated by RT-PCR and Western blotting. Results: Nano-encapsulation significantly improved the antioxidant capacity and storage stability of the extract compared with non-encapsulated Cordyceps militaris grown on germinated Rhynchosia nulubilis (GRC). GCN markedly attenuated PM- and LPS-induced cytotoxicity and intracellular reactive oxygen species (ROS) production in a dose-dependent manner, resulting in a therapeutic index approximately 4.5-fold higher than that of GRC under PM and LPS co-exposure. Bioinformatics analysis identified inflammation-related genes and pathways associated with PM- and LPS-induced pulmonary responses, primarily enriched in tumor necrosis factor (TNF)-related inflammatory pathways, Toll-like receptor signaling, and cytokine signaling. Consistent with these findings, GCN suppressed the expression of C-X-C motif chemokine ligand 2 (CXCL-2) and tumor necrosis factor-alpha (TNF-α) mRNA and inhibited mitogen-activated protein kinase (MAPK)-mediated activator protein-1 (AP-1) and nuclear factor-kappa B (NF-κB) signaling pathways in human type II alveolar epithelial cells (A549). Conclusions: Collectively, nano-encapsulation enhanced the stability and bioactivity of Cordyceps militaris-based extracts, suggesting that GCN may have potential as a functional food-derived candidate ingredient to protect airway epithelial cells against inflammation and oxidative stress induced by PM and LPS. As this study was conducted using an in vitro A549 epithelial cell model, further validation in physiologically relevant systems is needed to confirm its translational applicability. Full article

Mucosal immunity in the respiratory tract provides the first line of defense against airborne pathogens, yet most current vaccines fail to induce strong and durable immune responses at these sites. Respiratory viruses, including respiratory syncytial virus (RSV), influenza viruses, and coronaviruses, remain major global health threats, in part due to their ability to evade long-term mucosal protection. Although systemic vaccination generates robust circulating immunity, it induces limited local responses, particularly secretory immunoglobulin A (IgA), which is critical for preventing viral entry and transmission at the airway surface. The mechanisms regulating B cell responses within the airway mucosa are not fully understood. B cell–activating factor (BAFF), a member of the tumor necrosis factor (TNF) superfamily, has emerged as an important context-dependent regulator of mucosal B cell immunity. BAFF is produced by airway epithelial cells and multiple myeloid populations, including dendritic cells and neutrophils, and is rapidly induced during respiratory viral infection through type I interferon–dependent pathways. Functionally, BAFF supports B cell survival, differentiation, and class-switch recombination, promoting the generation of antibody-secreting plasma cells and enhancing IgA production. In the lung, these effects align with early, intermediate, and late stages of the response, supporting initial local antibody production, the formation of inducible bronchus-associated lymphoid tissue (iBALT), and the development of tissue-resident memory B cells that sustain long-term immunity. Although BAFF plays an essential role in mucosal immunity, its activity requires tight regulation to maintain immune balance. Current evidence supports BAFF as a promising immunomodulatory component and highlights its potential as an adjuvant platform for enhancing mucosal vaccine efficacy, warranting further investigation as a potential adjuvant in this context. Full article

Asthma represents a chronic inflammatory condition of the respiratory tract, where long-term bronchial inflammation serves as a primary driver of progressive airway remodeling. This complex pathology emerges from the intricate synergy between host genetic susceptibility and diverse environmental triggers, ultimately impairing pulmonary function. At the cellular level, asthmatic responses are orchestrated by a dynamic crosstalk among various immune and structural populations, including airway epithelial cells, T-lymphocytes, eosinophils, and mast cells, which collectively perpetuate the inflammatory milieu. Although inhaled corticosteroids are the conventional cornerstone of therapy, their clinical application is frequently hindered by potential systemic toxicity and the emergence of steroid-resistant phenotypes. Consequently, botanical extracts derived from both aerial and underground plant organs have gained attention as versatile multi-target candidates capable of modulating the multifaceted pathophysiological networks of asthma. This scoping review critically synthesizes the pharmacological efficacy of these plant-based interventions in regulating pivotal signaling cascades, such as MAPK, NF-κB, STAT3/6, and GATA3. Based on a systematic literature search covering the period from 2005 to 2025, this study provides a focused quantitative analysis of preclinical literature from the last decade (2016–2025) to evaluate the in vitro and in vivo models employed to validate these therapeutic effects. The assessment reveals that the vast majority of current research continues to rely on crude botanical preparations, with only a limited subset of studies utilizing enriched fractions or fully characterized isolated compounds. This predominance of unrefined extracts underscores a significant gap in chemical standardization and highlights the necessity for more rigorous mechanistic validation. Ultimately, this paper outlines strategic pathways for translating preclinical findings into clinical practice, offering a robust framework for the development of standardized plant-derived interventions in asthma management. Full article

Inflammation at the superior airway level has multiple manifestations, and allergic rhinitis and chronic rhinosinusitis with or without polyps are two of the most frequent and troublesome of them, with innate and adaptive immunity being implicated. Dendritic cells, epithelial cells, neutrophils, macrophages, mucosal mast cells, eosinophils, basophils, innate lymphoid cells (ILCs), and NK cells are the players in innate immunity, while regulatory T (Treg), TH1, TH2, TH17, T follicular helper, and B cells are components of the adaptative immune system. Th9 cells, a subset of T helper cells discovered in 2008 that produce interleukin-9 (IL-9), play a vital role in the adaptive immune response and have advantageous and harmful effects in different diseases due to the induction pattern. We queried international databases for current, up-to-date information regarding the interplay between interleukin 9 (IL-9) and helper T cells (especially Th9 cells), and by other immune cells. Interleukin-9 has multiple immunological functions, acting on various target cells through its specific receptor (IL-9R), such as the following: the regulation of allergic (Th2-type) immune responses; effects on epithelial and mucosal cells, mast cells, and eosinophils; chronic inflammation; and autoimmunity. Thus, there is a further need to translate laboratory findings into clinical practice regarding IL-9. Full article

Pertussis is a highly contagious respiratory infection caused by Bordetella pertussis and remains a persistent global health challenge despite widespread vaccination. This review aims to analyze the immune pathogenesis of B. pertussis infection and to identify key immunological limitations of current acellular pertussis vaccines that contribute to ongoing transmission. A narrative review of the literature was conducted, focusing on mechanisms of host–pathogen interaction, immune evasion, and vaccine-induced immunity. Evidence indicates that although acellular vaccines effectively reduce disease severity, they fail to prevent nasopharyngeal colonization and transmission, largely due to insufficient induction of mucosal immunity, T helper 1 (Th1) and T helper 17 (Th17) responses, and airway tissue-resident memory T cells. In contrast, natural infection induces broader immune responses, including secretory IgA production and robust cellular immunity, which are associated with improved bacterial clearance. Emerging next-generation vaccine strategies, including mucosal, outer membrane vesicle-based, and live-attenuated platforms, demonstrate enhanced ability to reduce bacterial colonization in preclinical and clinical models. In conclusion, effective control of pertussis transmission will require vaccine approaches that replicate infection-induced immunity at the respiratory mucosa, emphasizing the need for redesigned immunization strategies. Full article

Respiratory infections remain a leading cause of morbidity and mortality worldwide, highlighting the urgent need to better understand host defense mechanisms in the respiratory tract. Recent advances in sequencing technologies have challenged the traditional view of the lungs as sterile organs and revealed the presence of a distinct, low-biomass microbial community known as the lung microbiota. These microbial populations interact closely with airway epithelial cells and immune cells to maintain respiratory homeostasis and regulate host immune responses. In healthy lungs, microbial communities dominated by Firmicutes, Bacteroidetes, and Proteobacteria contribute to immune regulation through interactions with innate and adaptive immune pathways. Microbiota-derived signals are detected by pattern recognition receptors, activating signaling pathways that regulate cytokine production, immune cell recruitment, and T-cell differentiation. In the respiratory mucosa, microbial stimulation can also induce epithelial and antigen-presenting cells to produce B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL), which promote immunoglobulin A (IgA) class-switch recombination and support mucosal antibody responses. During pulmonary infection, disruption of microbial communities can lead to dysbiosis that amplifies inflammatory responses, impairs epithelial barrier integrity, and increases susceptibility to secondary bacterial infections. In addition to local microbial interactions, the gut–lung axis represents a key communication pathway linking intestinal microbiota with respiratory immunity through microbial metabolites such as short-chain fatty acids (SCFAs) and immune signaling networks. This review summarizes current insights into microbiota–immune crosstalk in the lung during pulmonary infection and discusses how these interactions may inform mucosal vaccine development. A deeper understanding of host–microbiota interactions may enable microbiome-informed vaccines and therapeutic strategies to improve protection against respiratory diseases. Full article

CX3CR1 is a chemokine receptor expressed on respiratory epithelial and immune cells and has been identified as a host factor important for infections with respiratory syncytial virus (RSV). In this review, we discuss the roles CX3CR1 plays in the pathogenesis of RSV infections as a viral entry receptor and regulator of immune cell trafficking. The conserved CX3C motif of the RSV G glycoprotein binds to CX3CR1 to mediate viral attachment and entry into respiratory epithelial cells. Furthermore, soluble G protein (sG) can bind to CX3CR1 and competitively interfere with cell signaling induced by the chemokine CX3CL1, resulting in inhibition of immune cell recruitment to the site of infection. In addition, sG engages TLR2 on epithelial cells, activating MyD88-NF-κB signaling and priming the NLRP3 inflammasome, which enhances viral dissemination through pyroptotic cell death. CX3CR1 signaling should be viewed as one of several overlapping host factors that—along with developmental changes in interferon and STAT3 signaling, airway anatomy, inflammasome activity, and tissue-resident memory responses—contribute to differential disease outcomes of RSV infection. A more complete molecular understanding of RSV-CX3CR1 interactions and downstream host responses may enable the development of improved prevention and treatment strategies. Full article

Mucins are highly glycosylated proteins that form the structural basis of mucus and represent a key component of innate immunity at mucosal surfaces, particularly in the respiratory tract. Beyond their mechanical barrier function, mucins actively participate in pathogen trapping, regulation of mucociliary clearance, modulation of inflammatory responses, and maintenance of epithelial homeostasis. Dysregulation of mucin synthesis, composition, or transport contributes to mucus hypersecretion, impaired airway clearance, and chronic inflammation in respiratory diseases such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis. This review summarizes current insights into mucin biology, including their biosynthesis, structure, classification, and regulation, with emphasis on the gel-forming mucins MUC5AC and MUC5B. The role of mucins in mechanical protection, host–pathogen interactions, control of inflammation, and coordination of innate immune responses is reviewed. Attention is given to the interplay between mucins, immune cells, and microbial communities in maintaining airway barrier integrity. The article further examines mucoactive therapeutic strategies aimed at restoring mucus barrier function. Expectorants, mucolytics, mucoregulators, and mucokinetic agents are reviewed with respect to their mechanisms of action and clinical relevance. Established drugs, including N-acetylcysteine, carbocysteine, dornase alfa, ambroxol, and hypertonic solutions, are considered alongside emerging molecular targets such as NF-κB-dependent regulation of mucin expression, calcium-activated chloride channels, MARCKS-mediated mucin exocytosis, purinergic signaling pathways, and NO/cGMP signaling. Non-pharmacological approaches, including airway clearance techniques and respiratory rehabilitation, are covered concisely. Conclusions: Overall, this review highlights mucins as dynamic regulators of innate immunity and underscores the need for mechanism-based, personalized mucoactive therapies to improve outcomes in chronic inflammatory airway diseases. Full article

Brucella infection is frequently acquired by inhalation, but the pathogen disseminates systemically from the lungs. However, little is known about the interaction of Brucella spp. with the airways. Using a 3D air-exposed organotypic human bronchial tissue model (polarized 16HBE14o- bronchial epithelial cells grown over a collagen matrix containing MRC-5 lung fibroblasts), we analyzed Brucella abortus replication, translocation and cytokine responses over prolonged post-infection times. Apically inoculated B. abortus invaded, replicated and persisted during the whole follow-up (16 days) within the bronchial tissue without inducing cytotoxicity. Viable bacteria were also detected in the conditioned medium (CM) since day five post-infection, indicating release from the basolateral side. In parallel experiments, no invasion or bacterial release was detected for Escherichia coli. The levels of IL-6, IL-8 and MCP-1 were increased in CM from Brucella-infected 3D cultures and in monocultures of polarized bronchial epithelial cells or lung fibroblasts. Collagenase/gelatinase activity was increased in 3D cultures and MRC-5 monocultures. Infection transference from bronchial cells to lung fibroblasts was documented using monocultures. An immune cross-talk was detected, as cytokine levels were increased in fibroblasts stimulated with bronchial CM, and vice versa. These results suggest that the bronchial mucosa can sustain B. abortus persistence, replication and dissemination, and that it induces a proinflammatory response to which both epithelial cells and fibroblasts contribute. Full article

Human rhinovirus (HRV) is one of the common respiratory viral infection agents that triggers airway obstruction and asthma exacerbations, especially during childhood. This project aimed at evaluating the mechanism of ultraviolet (UV) and infrared (IR) radiations to inactivate HRV infection and replication inside and outside infected airway epithelial cells and the resulting impact on interferon responses and epithelial barrier integrity. Hereby, airway epithelial cells were infected with different RV concentrations. Later these cells are exposed to UV and IR light to analyze their impact on the viral immune response of the host by real-time PCR. It was found that RV1B disrupted cell junctions of airway epithelial cell barriers. Moreover, high doses of RV1B activated pattern recognition receptor (TLR3), induced interferon (IFN-β) response and reduced SOCS1, which is a negative regulator of IFN-β. Further, IR lights inhibited rhinovirus post infection in primary nasal epithelial cells (NECs). Finally, UVC exposure significantly inhibited the antiviral effects of the host via SOCS1 inhibition and decreased RV1B within 72 h. Collectively, these findings support the role of UV light as an effective therapeutic approach for acutely eliminating RV but resulting in barrier and antiviral damage, which can have a drawback effect for asthma. Full article

Periodontal pathogens, including Porphyromonas gingivalis (P. gingivalis), are implicated in respiratory inflammatory conditions, and aspirated oral bacterial components may contribute to airway inflammation. This association has prompted the exploration of innovative therapeutic strategies in addition to conventional oral hygiene practices. We evaluated the anti-inflammatory efficacy of an alkaline extract of Sasa senanensis leaves (SE) against heat-inactivated P. gingivalis-induced inflammation in respiratory tissues. In human bronchial epithelial cells (BEAS-2B), SE reduced interleukin (IL)-6 and IL-8 mRNA expression and cytokine secretion in a dose-dependent manner. Moreover, SE attenuated nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs), including p38 and c-Jun N-terminal kinase (JNK), indicating broad anti-inflammatory actions. In mice, SE administration decreased early lung cytokine levels and reduced NF-κB activity following intratracheal challenge with heat-inactivated P. gingivalis. Together, these in vitro and in vivo findings indicate that SE suppresses proinflammatory signaling triggered by P. gingivalis components and may serve as a natural adjunct to mitigate bacteria-associated airway inflammatory responses. Full article

Background: Chronic obstructive pulmonary disease (COPD) is a progressive inflammatory lung disorder with limited effective therapies. NRICM102, a traditional multi-herbal formulation originally developed for COVID-19, exhibits anti-inflammatory and immunomodulatory potential. Objectives: The aim of this study was to investigate the therapeutic efficacy of NRICM102 in a COPD-relevant inflammatory lung injury mice model. Methods: Mice were exposed to lipopolysaccharide (LPS) and benzo[a]pyrene (B[a]P) to induce chronic airway inflammation and structural lung damage and treated with NRICM102 (1.5–3.0 g/kg) or dexamethasone. Lung function, histopathology, transcriptomic profiling, and protein expression of key inflammatory markers were assessed. Results: NRICM102 significantly restored LPS+B[a]P-induced enhanced pause (Penh) and arterial oxygen saturation (aO₂%), similar to the effect of dexamethasone. Histological analysis revealed marked alveolar damage, inflammatory cell infiltration, and fibrosis in the model group, all of which were significantly attenuated by NRICM102 in a dose-dependent manner, with high-dose (3.0 g/kg) treatment showing pronounced structural preservation. Transcriptomic profiling revealed that NRICM102, particularly at 3.0 g/kg, partially reversed COPD-associated gene expression patterns, characterized by reduced activation of cytokine signaling, chemokine activity, and antigen presentation pathways. GO, DO, and KEGG enrichment analyses indicated selective modulation of immune-related pathways, with high-dose NRICM102 affecting genes involved in adaptive immunity and cytokine receptor interactions, including a subset of 150 reverted genes. Immunofluorescence analysis confirmed dose-dependent reductions in key inflammatory, immune, and mucus-related markers, including IL-1β, NLRP3, Muc5ac, and MMP12 expression. Conclusions: NRICM102 confers significant protective effects against COPD-relevant inflammatory lung injury by improving pulmonary function, preserving lung architecture, and selectively modulating immune and inflammatory pathways. These results provide preclinical evidence supporting the potential of NRICM102 to modulate inflammation and immune responses associated with COPD-related pathology, although further studies are needed to establish its therapeutic relevance. Full article

Background/Objectives: Respiratory Syncytial Virus (RSV) causes severe disease in infants, the elderly, and immunocompromised individuals, with reinfections linked to poor induction of durable mucosal immunoglobulin A (IgA). We investigated the role of IgA in immunity and protection induced by a RSV subunit vaccine candidate, tFrsc/TriAdj, which consists of a truncated RSV fusion protein (tFrsc) with a tri-component adjuvant (TriAdj). Methods: Wild-type (IgA⁺/⁺) and IgA-deficient (IgA⁻/⁻) BALB/c mice were immunized intranasally and subsequently challenged with RSV. Results: Vaccination with tFrsc/TriAdj induced robust systemic and mucosal IgG, and high lung and serum neutralizing antibodies, in both IgA⁺/⁺ and IgA⁻/⁻ mice. As expected, IgA⁻/⁻ mice lacked IgA and exhibited modest reductions in nasal IgG compared to IgA^+/+ mice following challenge, correlating to failure to clear RSV from the upper respiratory tract. In contrast, viral replication in the lungs was fully suppressed in both genotypes, indicating that IgG alone was sufficient for lower respiratory tract protection. Isotype analysis revealed diminished Th1-associated IgG2a and elevated IgG1 across mucosal and systemic compartments in IgA⁻/⁻ mice, suggesting a Th2 bias. Flow cytometric analysis confirmed reduced recruitment of IFN-γ⁺ CD4⁺ T cells in the lungs of immunized IgA⁻/⁻ mice. Interestingly, IL-17 production and numbers of IL-17⁺ CD4⁺ T cells in the lungs were increased, suggesting an enhanced Th17 response. Furthermore, IgA-deficient mice displayed reduced splenic IgG⁺ B cell populations, which is also a novel observation. Conclusions: Collectively, these findings demonstrate that although tFrsc/TriAdj confers lower airway protection in the absence of IgA, vaccine-induced IgA is critical for upper airway protection, Th1/balanced immune responses, and optimal B cell responses. Full article

Objective: Ongoing debates focus on the role of human leukocyte antigen (HLA) class II expression in shaping clinical phenotypes of chronic inflammatory airway diseases. This study seeks to clarify the impact of class II HLA on chronic obstructive pulmonary disease (COPD) and asthma–COPD overlap (ACO). Method: The expression levels of HLA-DQ/DR in blood immune cells were analyzed in 116 participants: 41 with COPD, 37 with ACO, 20 with pure asthma, and 18 healthy subjects (HS). Results: In the COPD group, HLA-DR protein expression levels were significantly elevated on blood M2a monocytes (7695 ± 3743 vs. 5391 ± 3153 MFI, p = 0.026), helper T cells (2551 ± 956 vs. 1836 ± 531 MFI, adjusted p = 0.018), cytotoxic T cells (1591 ± 531 vs. 1360 ± 477 MFI, adjusted p = 0.036), and B cells (20,667 ± 7985 vs. 15,694 ± 2003 MFI, adjusted p = 0.031) compared to the HS group. Conversely, no significant changes were observed in the asthma group. In ACO patients, helper T cells showed increased HLA-DR protein expression (2416 ± 914 MFI; adjusted p = 0.016) compared with the HS group. Higher levels of HLA-DR expression correlated with reduced pulmonary function, frequent exacerbations, and more severe symptoms. Following one year of treatment in 14 COPD and 16 ACO patients, HLA-DR protein expression on blood helper T cells, cytotoxic T cells, M2a monocytes, and neutrophils significantly declined (all p < 0.05). In vitro experiments demonstrated that exposure of M2- or M1-polarized THP-1 cells to a stimulus mix containing cigarette smoke extract, house dust mite antigens, and lipopolysaccharide led to up-regulation of HLA-DR expression. This response was linked to increased apoptosis and reduced production of reactive oxygen species. Conclusions: Up-regulation of HLA-DR in COPD and ACO patients may represent a novel biomarker for assessing disease severity and treatment response. Additionally, it could serve as a useful tool to distinguish COPD and ACO from asthma. Full article

The development of new approach methodologies that include human cells differentiated into organotypic formats is of high interest due to their structural and functional similarities to tissues in vivo, enabling mechanistic understanding and translation to adverse health outcomes in humans. However, these systems often fail to capture complex intercellular signaling required for processes such as pulmonary inflammation induced by polycyclic aromatic hydrocarbons (PAHs). To investigate airway epithelial–macrophage interactions in response to benzo[a]pyrene and a PAH mixture (Tox Mix), co-culture models utilizing primary human bronchial epithelial cells (HBECs) differentiated at the air–liquid interface were cultured with THP-1 macrophages either directly or indirectly, alongside HBECs alone. After 24 h of exposure, cytokine expression (IL1B, IL6, CXCL8, TNF) as well as PAH biomarkers previously identified for chemical metabolism (CYP1A1, CYP1B1), oxidative stress (ALDH3A1, HMOX1, NQO1), and barrier integrity (TJP2) were evaluated. Cytotoxicity and barrier integrity were also assessed. HBECs alone and direct co-cultures exhibited similar responses after PAH treatment, while indirect co-cultures showed lower sensitivity to induction of inflammatory cytokines and CYP1A1 and CYP1B1 biomarker expression following exposure to PAHs. The expression of other biomarkers, including ALDH3A1, HMOX1, and NQO1, remained largely consistent across all models after treatment. Overall, these findings suggest that direct co-culture systems may provide a more physiologically relevant platform for studies of PAH-induced toxicity and demonstrate that the configuration of co-culture systems can influence cellular responses to chemical exposure. Full article