Innate Type-2 Cytokines: From Immune Regulation to Therapeutic Targets

Particulate matter exposure induces pulmonary TH2 responses and oxidative stress-mediated NRF2 activation in mice

INTRODUCTION

Particulate matter (PM) is a harmful air pollutant associated with respiratory and cardiovascular diseases, but its effects on adaptive immunity are poorly understood.

OBJECTIVES

This study investigates the role of NRF2 in T cells in mediating immune and pulmonary responses to long-term PM exposure, highlighting its impact on inhalation toxicity.

METHODS

To establish a mouse model of lung injury induced by PM exposure, C57BL/6 mice were intranasally administered 20 μg/kg PM10 or PM2.5 daily for 16 weeks. Lung injury parameters were analyzed in bronchoalveolar lavage fluid (BALF), plasma, and lung tissue. Changes in the proportion of immune cells in the lymph nodes and spleen were analyzed.

RESULTS

Mice exposed to PM for 16 weeks showed severe lung damage, such as inflammatory cell infiltration, thickened alveolar walls, and increased oxidative stress and apoptosis. PM exposure also increased collagen and fibronectin levels, indicating tissue remodeling. Immune cell analysis revealed reduced B cell expansion, increased IL-4-producing CD4+ T cells, and decreased IFN-γ- and TNF-α-producing CD4+ T cells, accompanied by higher TH2 cytokines and plasma IgE and IgG1 levels. PM activated the NRF2 pathway, skewing immune responses toward TH2 differentiation, which worsened lung inflammation.

CONCLUSIONS

These findings highlight how PM exposure disrupts immune balance and exacerbates conditions like asthma and chronic obstructive pulmonary disease by promoting TH2-driven inflammation through NRF2 activation.

Adult Hymenolepis nana and its excretory-secretory products elicit mouse immune responses via tuft/IL-13 and FOXM1 signaling pathways

BACKGROUND

Hosts typically elicit diverse immune responses to the infection of various parasitic worms, with intestinal epithelial cells playing pivotal roles in detecting parasite invasion. Hymenolepis nana (H. nana) is a zoonotic parasitic worm that resides in the host's intestine. The contribution and underlying mechanisms of tuft cell-mediated immune reactions against H. nana remain unexplored.

METHODS

This study endeavors to examine the immune responses in the mouse intestine elicited by the adult H. nana and its excretory-secretory products (ESP). Ileal tissue alteration was detected using hematoxylin and eosin (H&E) staining, changes in the number of intestinal stem cells, goblet cells, tuft cells, and Paneth cells were detected by immunohistochemistry (IHC), immunofluorescence (IF), etc., and changes in the expression of type 2 cytokines and FOXM1 were detected by Western blotting (WB) or real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

The presence of adult H. nana and its ESP enhanced the number of tuft cells and goblet cells while fostering the production of type 2 cytokines. Furthermore, the surge in Paneth cells and FOXM1 triggered by H. nana aids in maintaining intestinal stem cells homeostasis and proliferation. Notably, the FOXM1 inhibitor RCM-1 dampened intestinal stem cells differentiation and type 2 cytokines secretion, potentially impeding the host's capacity to eliminate H. nana.

CONCLUSIONS

The adult H. nana and its ESP stimulate the immune responses in mice through tuft/interleukin (IL)-13 and FOXM1 signaling pathways and promote the elimination of H. nana from the host through the differentiation of intestinal stem cells into tuft cells, goblet cells, and Paneth cells, as well as the activation of type 2 immune responses. Meanwhile, RCM-1 inhibits the immune responses to H. nana in mice, thus affecting the excretion of H. nana by host.

Tissue-Specific Metabolic Reprogramming in Innate Lymphoid Cells and Its Impact on Disease

Recent advances have highlighted the crucial role of metabolic reprogramming in shaping the functions of innate lymphoid cells (ILCs), which are vital for tissue immunity and homeostasis. As tissue-resident cells, ILCs dynamically respond to local environmental cues, with tissue-derived metabolites such as short-chain fatty acids and amino acids directly modulating their effector functions. The metabolic states of ILC subsets-ILC1, ILC2, and ILC3-are closely linked to their ability to produce cytokines, sustain survival, and drive proliferation. This review provides a comprehensive analysis of how key metabolic pathways, including glycolysis, oxidative phosphorylation, and fatty acid oxidation, influence ILC activation and function. Furthermore, we explore the complex interactions between these metabolic pathways and tissue-specific metabolites, which can shape ILC-mediated immune responses in health and disease. Understanding these interactions reveals new insights into the pathogenesis of conditions such as asthma, inflammatory bowel disease, and cancer. A deeper understanding of these mechanisms may not only advance our knowledge of disease pathogenesis but also lead to the development of novel therapeutic strategies targeting metabolic pathways in ILCs to treat tissue-specific immune disorders.

E3 ligase RNF128 restricts A. alternata-induced ILC2 activation and type 2 immune response in the murine lung

Allergic airway inflammation is a universal airway disease induced by inhaling allergens. Published data show that RNF128, an E3 ligase, promotes Th2 activation in the OVA-induced asthma model. Recent advances have shown that group 2 innate lymphoid cells (ILC2s) produce the cytokines IL-5 and IL-13 to mediate type 2 immune response. However, whether RNF128 regulates ILC2-dependent allergic lung inflammation remains unclear. In this study, we observed greater expression of the E3 ligase RNF128 in ILC2s than in other immune cells. RNF128 deficiency caused a selective increase in the number of peripheral mature ILC2s, and mice with RNF128 deficiency were more susceptible to Alternaria alternata (A. alternata) -induced allergic lung inflammation. Furthermore, RNF128 deficiency increased recruitment of eosinophils and levels of IL-5 and IL-13 in the bronchoalveolar lavage fluid. RNF128 effectively inhibited the expansion of ILC2s and the number of IL-5- and IL-13-producing ILC2s. Specially, RNF128 deficiency promoted the expression of the interleukin-33 (IL-33) receptor ST2 in A. alternata-induced allergic lung inflammation. Above all, our study demonstrated that RNF128 played a key role in A. alternata-induced ILC2 activation and type 2 immune response, suggesting that RNF128 may be an effective therapeutic target for allergic lung inflammation initiated by ILC2s.

Type 3 immune response protects against Salmonella Typhimurium infection in the small intestine of neonatal rats

Bacterial infections, particularly Salmonella, pose a significant health risk to neonates due to their underdeveloped immune systems. Understanding the immune responses in the neonatal intestine during S. Typhimurium infection is crucial for developing effective therapeutic and prevention strategies. This study found neonatal rats exhibited severe symptoms, including significant mortality, body weight loss, diarrhea, and bacterial load increases in the gastrointestinal tract and various organs, particularly in the ileum. Moreover, neonatal rats exhibited a high percentage of type 3 immune cells including Th17, γδT17, and ILC3 after S. Typhimurium infection. Furthermore, cintirorgon treatment during early life, the agonist of RORγt, significantly enhanced IL-17A-secreting type 3 immune response and alleviated the symptoms. Our data reveal targeting RORγt and IL-17A pathways may offer a promising therapeutic strategy for bacterial infections in neonatal populations.

Bifidobacterium breve DSM 32583 and Limosilactobacillus fermentum CECT5716 postbiotics attenuate S. aureus and IL-33-induced Th2 responses

Over the past decades, the prevalence of allergic diseases noticeably increased in industrialized countries. The Th2 immune response plays a central role in these pathologies and its modulation using pro-/postbiotics constitutes a promising approach to prevent or alleviate disease symptoms. The aim of this in vitro study, was to investigate the ability of human milk-derived Bifidobacterium breve DSM 32583 (Bb) and Limosilactobacillus fermentum CECT5716 (Lf), to modulate the Th2 induced responses. To this end, Th2 cells were generated by co-culturing of human naïve Th cells with monocyte-derived dendritic cells (moDCs) either stimulated with Staphylococcus aureus or IL-33. The immunomodulatory effects of pro-/postbiotic preparations of Bb and Lf on moDCs and Th2 cells were evaluated in terms of maturation markers expression and cytokines production. Remarkably, the tested strains induced the anti-inflammatory cytokine IL-10 in moDCs, in a strain-, dose- and viability-dependent manner with no significant upregulation of IL-12p70 nor CD83, CD86 or HLA-DR. Interestingly, Bb and Lf postbiotics were able to dampen the Th2/Th1 response induced upon S. aureus- or IL-33 stimulation. They were also able to synergistically induce IL-10 in moDCs and T cells, upon co-stimulation with LPS. Finally, we observed that live probiotics triggered a mild Th1 response that was attenuated in the presence of galacto-oligosaccharides. Altogether, Bb and Lf pro-/postbiotics exhibited remarkable immune regulatory effects on both moDCs and Th2 cells. Therefore, further in vivo studies should be considered to validate these findings and assess their ability to prevent allergy or alleviate its symptoms in affected patients.

Quercetin inhibits ferroptosis through the SIRT1/Nrf2/HO-1 signaling pathway and alleviates asthma disease

Background

Quercetin (QCT) is a bioflavonoid derived from vegetables and fruits that has anti-inflammatory and anti-ferroptosis effects against various diseases. Previous studies have shown that QCT modulates the production of cellular inflammatory factors in asthma models and delays the development of chronic airway inflammation. However, the regulatory mechanism of QCT, a traditional Chinese medicine, in the treatment of asthma has not been elucidated. The aim of the present study is to investigate whether QCT can inhibit ferroptosis via the SIRT1/Nrf2 pathway and play a therapeutic role in asthma.

Methods

An ovalbumin-induced mouse asthma model was established, and its function was verified by hematoxylin eosin staining, enzyme linked immunosorbent assay, ferric ion assay, malondialdehyde and superoxide dismutase assays, dihydroethidium staining, immunohistochemical staining, western blotting, and quantitative real-time polymerase chain reaction.

Results

Our results indicated that an ovalbumin-induced asthma mouse model had been successfully established and that QCT inhibited inflammation, reduced serum levels of inflammatory factors IL-4, IL-5 and IL-13, increased superoxide dismutase levels in lung tissue homogenates, and reduced malondialdehyde and ferric ion production in asthmatic mice. In addition, we found that QCT was able to reverse the expression of SIRT1, Nrf2 and HO-1 in an in vivo asthma mouse model.

Conclusions

The data from this study indicate that QCT can alleviate asthma, and its mechanism is related to the regulation of ferroptosis, oxidative stress, and the expression of SIRT1 protein.

Weighted Breaths: Exploring Biologic and Non-Biologic Therapies for Co-Existing Asthma and Obesity

PURPOSE OF REVIEW

To discuss the effectiveness of biologics, some of which comprise the newest class of asthma controller medications, and non-biologics in the treatment of asthma co-existing with obesity.

RECENT FINDINGS

Our review of recent preliminary and published data from clinical trials revealed that obese asthmatics respond favorably to dupilumab, mepolizumab, omalizumab, and tezepelumab, which are biologics currently indicated as add-on maintenance therapy for severe asthma. Furthermore, clinical trials are ongoing to assess the efficacy of non-biologics in the treatment of obese asthma, including a glucagon-like peptide-1 receptor agonist, a Janus kinase inhibitor, and probiotics. Although many biologics presently indicated as add-on maintenance therapy for severe asthma exhibit efficacy in obese asthmatics, other phenotypes of asthma co-existing with obesity may be refractory to these medications. Thus, to improve quality of life and asthma control, it is imperative to identify therapeutic options for all existing phenotypes of obese asthma.