Molybdenum and cadmium co-induce necroptosis through Th1/Th2 imbalance-mediated endoplasmic reticulum stress in duck ovaries

Cadmium (Cd) and excess molybdenum (Mo) pose serious threats to animal health. Our previous study has determined that Cd and/or Mo exposure can cause ovarian damage of ducks, while the specific mechanism is still obscure. To further investigate the toxic mechanism of Cd and Mo co-exposure in the ovary, forty 8-day-old female ducks were randomly allocated into four groups for 16 weeks, and the doses of Cd and Mo in basic diet per kg were as follows: control group, Mo group (100 mg Mo), Cd group (4 mg Cd), and Mo + Cd group (100 mg Mo + 4 mg Cd). Cadmium sulfate 8/3-hydrate (CdSO4·8/3H2O) and hexaammonium molybdate ((NH4)6Mo7O24·4H2O) were the origins of Cd and Mo, respectively. At the 16th week of the experiment, all ovary tissues were collected for the detection of related indexes. The data indicated that Mo and/or Cd induced trace element disorders and Th1/Th2 balance to divert toward Th1 in the ovary, which activated endoplasmic reticulum (ER) stress and then provoked necroptosis through triggering RIPK1/RIPK3/MLKL signaling pathway, and eventually caused ovarian pathological injuries and necroptosis characteristics. The alterations of above indicators were most apparent in the joint group. Above all, this research illustrates that Mo and/or Cd exposure can initiate necroptosis through Th1/Th2 imbalance-modulated ER stress in duck ovaries, and Mo and Cd combined exposure aggravates ovarian injuries. This research explores the molecular mechanism of necroptosis caused by Mo and/or Cd, which reveals that ER stress attenuation may be a therapeutic target to alleviate necroptosis.

Potential of Lactobacillus plantarum A56 in relieving food allergy through immunoregulation, antioxidation, and reshaping intestinal microbiota

Food allergy is an abnormal immune reaction triggered by food protein antigens. Relevant studies have suggested that probiotic supplementation was with the potential to alleviate food allergy. This study aimed to explore the effects of Lactobacillus plantarum A56 on the alleviation of ovalbumin (OVA)-induced food allergy via immunomodulatory function, antioxidation, and modification of intestinal microbiota. Balb/c mice were sensitized with OVA (20 µg/mouse) by intraperitoneal injection for 3 weeks and accompanied by oral administration of L. plantarum A56 (109 CFU/mL), subsequently with orally challenged twice by OVA at 50 mg/mL for 1 week. The results showed that oral supplementation of L. plantarum A56 could effectively relieve allergic symptoms of mice, and decreased OVA-specific IgE and IgG1 concentrations. It also declined interleukin (IL)-4 level, raised interferon-γ (IFN-γ) in serum, and splenocyte supernatant, and the qPCR results were consistent with above results. Moreover, L. plantarum A56 treatment also fortified superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels, and reduced malondialdehyde (MDA) level in serum. The increased nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and forkhead box O1 (Foxo1) expression indicated that L. plantarum A56 exerted antioxidation through Nrf2-Foxo1 pathway. In addition, L. plantarum A56 treatment elevated Bacteroidetes richness, ASV/OTU number, species diversity, etc. Notably, Spearman correlation analysis indicated that Bacteroidetes displayed obviously negative correlation with IgE and IgG1, but Actinobacteria and Acidobacteria exhibited significantly positive correlation with IgG1 and IgE. Collectively, these results suggested that L. plantarum A56 could alleviate OVA-induced food allergy by regulating Th1/Th2 imbalance, antioxidation, and modulating intestinal microbiota.

Intestinal flora altered and correlated with interleukin-2/4 in patients with primary immune thrombocytopenia

BACKGROUND

Little is known about the changes and mechanisms of intestinal flora in primary immune thrombocytopenia (ITP) patients.

AIM

To explore the structural and functional differences of intestinal flora between ITP patients and healthy controls, and clarify the correlation between intestinal flora and Th1/Th2 imbalance.

METHODS

Feces from ITP patients and healthy controls were studied by 16S rRNA and metagenomic techniques at phylum, genus, species or functional levels. Blood samples were collected for the detection of interleukin -2 (IL-2) and IL-4 concentrations.

RESULTS

The following changes in ITP patients were found: a decrease of Bacteroidetes phylum, an increase of Proteobacteria phylum and alterations of ten genera and 1045 species. IL-2 and IL-4 were significantly correlated with six and five genera, respectively. Species of C. freundii, C. rodentium, and C. youngae were negatively correlated with bleeding scores, and S. infantis was positively related to platelet counts. Functionally, the intestinal flora of ITP patients changed mainly in terms of motility, chemotaxis, membrane transport, and metabolism.

CONCLUSION

The mechanism underlying functional and structural changes of intestinal flora in ITP patients may be related to inflammation and immunity, providing possibilities of probiotics or fecal transplants for ITP.

B Lymphocytes Balance Th1/Th2 to Participate in Fibrotic Hypersensitivity Pneumonia Induced by Pigeon Shedding

INTRODUCTION

We investigated the molecular mechanism by which B lymphocytes regulate Th1/Th2 imbalance to participate in the pulmonary fibrosis in hypersensitivity pneumonia induced by pigeon shedding in rats.

METHODS

CD19+ rats and CD19- rats were used to construct animal models of fibrotic hypersensitivity pneumonia. DAPT was used to inhibit the Notch signaling pathway. The pathological changes were assessed with HE and Masson staining. Protein level was detected with Western blot. Th1/Th2 ratio was analyzed with flow cytometry. Cytokine levels were measured with ELISA.

RESULTS

The pathological changes of pulmonary fibrosis were not obvious in the CD19- rats and after DAPT treatment. Notch signaling pathway proteins, including Notch1, Notch2, Jag1, Jag2, DLL1, and DLL4, in lung tissues of model rats were all significantly upregulated than those in control rats. However, these proteins in CD19- rats were lower in CD19+ rats, suggesting that B cells play a key role in inducing pneumonia. Besides, the Th1/Th2 ratio in the BALF of model rats decreased, which was further reversed by DAPT. However, we found that in CD19- rats, the regulation of the Th1/Th2 ratio by the Notch signaling pathway was lost.

CONCLUSION

Deleting B lymphocytes or blocking the Notch pathway both reversed the Th1/Th2 imbalance in fibrotic hypersensitivity pneumonia and inhibited pulmonary fibrosis.

Oral administration of Lactobacillus plantarum JC7 alleviates OVA-induced murine food allergy through immunoregulation and restoring disordered intestinal microbiota

PURPOSE

The incidence and prevalence of food allergy have sharply risen over the past several decades. Oral administration of probiotic stains has been proven as a safe and effective method to control food allergy. In this study, it aims to comprehensively investigate the anti-allergic effect of Lactobacillus plantarum JC7.

METHODS

Balb/c mice were randomly divided into three groups and received OVA (20 µg/mouse, intraperitoneal injection), L. plantarum JC7 (2 × 10⁸ CFU/mouse, intragastric administration) + OVA (20 µg/mouse, intraperitoneal injection) or 0.9% saline (intragastric administration) for 3 weeks. Body weight was monitored weekly, and allergic reactions were evaluated after challenge of OVA. Serum levels of OVA-specific immunoglobulins and various cytokines were tested using ELISA, and the cecum microbiota was analysed by 16S rRNA sequencing to explore the relationships between these indicators and OVA-induced food allergy. Western blotting was used to identify the expression levels of phosphorylated IκBα and nuclear factor kappa B p65.

RESULTS

OVA-sensitised mice showed mitigation of respiratory manifestations, alleviation of lung inflammation and congestion, and the presence of an intact intestinal villus structure. Furthermore, OVA-specific immunoglobulin E (IgE), OVA-specific-IgG1, and plasma histamine levels were declined in mice treated with L. plantarum JC7 than in OVA-sensitised mice. In addition, interferon-γ (IFN-γ) and interleukin 10 (IL-10) levels were significantly increased, while IL-4 and IL-17A levels were clearly decreased in mice that had undergone oral administration of L. plantarum JC7, compared with OVA-sensitised mice. These findings indicated imbalances of T helper cell type 1 (Th1)/Th2 and regulatory T cells (Treg)/Th17, which were confirmed by quantitative polymerase chain reaction (PCR). Western blotting demonstrated that the expression levels of phosphorylated IκBα and nuclear factor kappa B p65 were significantly increased in OVA-sensitised mice, but these changes were partly reversed after treatment with L. plantarum JC7. Oral administration of L. plantarum JC7 increased the richness, diversity, and evenness of cecum microbiota, characterised by higher Bacteroidetes abundance and lower Firmicutes abundance. Additionally, the intestinal microbial community composition was significantly altered in the OVA-sensitised group, indicating a disordered intestinal microbiota that was restored by the oral administration of L. plantarum JC7.

CONCLUSION

Overall, L. plantarum JC7 can prevent food allergy by rectifying Th1/Th2 and Treg/Th17 imbalances, combined with modifications of disordered intestinal microbiota.

α-Linolenic Acid Screened by Molecular Docking Attenuates Inflammation by Regulating Th1/Th2 Imbalance in Ovalbumin-Induced Mice of Allergic Rhinitis

α-Linolenic acid (ALA) is a natural essential fatty acid widely found in plant seed oils and beans, which shows positive anti-inflammatory and antiallergic effects. In our previous study, ALA was proven to bind tightly to the seven protein targets closely associated with allergic rhinitis (AR) by molecular docking, which indicates that ALA may have a potential role in the treatment of AR. A mouse model of AR induced by ovalbumin (OVA) was adopted in this study to explore the therapeutical effect and potential mechanism of ALA in treating AR. Results demonstrated that ALA remarkably relieved the nasal symptoms, reduced the OVA-sIgE level in the serum, relieved the histopathological injuries, and downregulated the mRNA expression levels of IL-6 and IL-1β in the nasal mucosa. ALA also remarkably moderated the imbalance of Th1/Th2 cells, increased the mRNA expression levels of T-bet and STAT1, and reduced GATA3 and STAT6. ALA was proven to have a substantial therapeutic effect on mice with AR, and the underlying mechanism was likely to be the regulation of Th1/Th2 imbalance through the JAK/T-bet/STAT1 and JAK/GATA3/STAT6 pathways. This study provides a specific experimental basis for the clinical use and drug development of ALA in the treatment of AR.

Molybdenum and cadmium co-exposure induces endoplasmic reticulum stress-mediated apoptosis by Th1 polarization in Shaoxing duck (Anas platyrhyncha) spleens

Excessive molybdenum (Mo) and cadmium (Cd) are deleterious to animals, but immunotoxicity co-induced by Mo and Cd remains unclear. To ascertain the confederate impacts of Mo and Cd on endoplasmic reticulum (ER) stress-mediated apoptosis by Helper T (Th) cells 1 polarization in the spleen of ducks, we randomly allocated forty 8-day-old Shaoxing ducks (Anas platyrhyncha) into 4 groups and reared them with having different doses of Mo and/or Cd basic diet. At the 16th week of the experiment, serum and spleen tissues were extracted. Data confirmed that Mo and/or Cd strikingly promoted their levels in spleen, caused histological abnormality and trace elements imbalance, and disrupted Th1/Th2 balance to divert toward Th1, then triggered ER stress by increasing three branches PERK/eIF2α/CHOP, IRE1/Caspase-12 and TRAF2/JNK signaling pathways-related genes mRNA and proteins levels, which stimulated apoptosis by elevating Bak-1, Bax, Caspase-9, Caspase-3 mRNA expression, and cleaved-Caspase-9/Caspase-9, cleaved-Caspase-3/Caspase-3 proteins expression as well as apoptosis rate, and decreasing Bcl-xL, Bcl-2 mRNA expression and Bcl-2/Bax ratio. Besides, the variation in combined group was most evident. Briefly, the study indicates that Mo and/or Cd exposure trigger ER stress-induced apoptosis via Th1 polarization in duck spleens, and its mechanism is somehow closely linked with the deposition of Cd and Mo, which may aggravate toxic damage to spleen.

Complex molecular mechanism of ammonia-induced apoptosis in chicken peripheral blood lymphocytes: miR-27b-3p, heat shock proteins, immunosuppression, death receptor pathway, and mitochondrial pathway

Ammonia gas, a toxic environmental pollutant, is a vital component of PM2.5 aerosols, and can decrease human and animal immunity. Peripheral blood lymphocytes (PBLs) are main immune cells. Nevertheless, poisoning mechanism of PBLs under ammonia exposure remains unclear. Here, we established an ammonia poisoning model of chicken PBLs to explore poisoning mechanism of ammonia-caused apoptosis in chicken PBLs. Cell viability and apoptosis rate were detected using CCK8 assay and flow cytometry, respectively. Mitochondrial membrane potential (MMP) was observed using fluorescent staining. In addition, qRT-PCR was performed to measure mRNA levels of apoptosis-related genes (tumor necrosis factor-α (TNF-α), tumor necrosis factor receptor 1 (TNFR1), TNF receptor-associated death domain (TRADD), Fas-associated death domain (FADD), Caspase-8, BH3-interacting domain death agonist (Bid), Bcl-2-associated X protein (Bax), Bcl-2 homologous antagonist/killer (Bak), B-cell lymphoma-2 (Bcl-2), Cytochrome-c (Cytc), apoptotic protease activating factor-1 (APAF1), Caspase-9, and Caspase-3), immune-related genes (interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, IL-6, IL-1β, IL-10, transforming growth factor-β1 (TGF-β1), IL-17, IL-21, and IL-22), heat shock protein (HSP) genes (HSP25, HSP40, HSP60, HSP70, HSP90, and HSP110), as well as miR-27b-3p. Western blot was used to determine protein levels of apoptosis-related factors (TNF-α, Caspase-8, Bcl-2, Caspase-9, and Caspase-3), as well as HSPs (HSP40, HSP60, HSP70, and HSP90). The results indicated that TRADD, FADD, and APAF1 were target genes of miR-27b-3p, as well as miR-27b-3p participated in molecular mechanism of apoptosis through targeting TNF-α/TNFR1/Caspase-8 death receptor pathway-triggered Bid/Cytc/Caspase-9 mitochondrial pathway in ammonia-treated chicken PBLs. In addition, our findings demonstrated that excess ammonia led to immunosuppression via Th1/Th2 imbalance and Treg/Th17 imbalance. Simultaneously, ammonia stress activated HSPs. In summary, for the first time, our data demonstrated that HSPs-triggered immunosuppression led to apoptosis under ammonia exposure. Our findings provided a new insight into molecular mechanism of ammonia poisoning and an important reference for environmental risk assessment related to ammonia.

Schisandrin B Induced ROS-Mediated Autophagy and Th1/Th2 Imbalance via Selenoproteins in Hepa1-6 Cells

Schisandrin B (Sch B) is well-known for its antitumor effect; however, its underlying mechanism remains confusing. Our study aimed to investigate the role of selenoproteins in Sch B-induced autophagy and Th1/Th2 imbalance in Hepa1-6 cells. Hepa1-6 cells were chosen to explore the antitumor mechanism and were treated with 0, 25, 50, and 100 μM of Sch B for 24 h, respectively. We detected the inhibition rate of proliferation, transmission electron microscopy (TEM), monodansylcadaverine (MDC) staining, reactive oxygen species (ROS) level and oxidative stress-related indicators, autophagy-related genes, related Th1/Th2 cytokines, and selenoprotein mRNA expression. Moreover, the heat map, principal component analysis (PCA), and correlation analysis were used for further bioinformatics analysis. The results revealed that Sch B exhibited well-inhibited effects on Hepa1-6 cells. Subsequently, under Sch B treatment, typical autophagy characteristics were increasingly apparent, and the level of punctate MDC staining enhanced and regulated the autophagy-related genes. Overall, Sch B induced autophagy in Hepa1-6 cells. In addition, Sch B-promoted ROS accumulation eventually triggered autophagy initiation. Results of Th1 and Th2 cytokine mRNA expression indicated that Th1/Th2 immune imbalance was observed by Sch B treatment in Hepa1-6 cells. Intriguingly, Sch B downregulated the majority of selenoprotein expression. Also, the heat map results observed significant variation of autophagy-related genes, related Th1/Th2 cytokines, and selenoprotein expression in response to Sch B treatment. PCA outcome suggested the key role of Txnrd1, Txnrd3, Selp, GPX2, Dio3, and Selr with its potential interactions in ROS-mediated autophagy and Th1/Th2 imbalance of Hepa1-6 cells. In conclusion, Sch B induced ROS-mediated autophagy and Th1/Th2 imbalance in Hepa1-6 cells. More importantly, the majority of selenoproteins were intimately involved in the process of autophagy and Th1/Th2 imbalance, Txnrd3, Selp, GPX2, Dio3, and Selr had considerable impacts on the process.

Aberrant expression of long non-coding RNA PVT1 in allergic rhinitis children: Correlation with disease risk, symptoms, and Th1/Th2 imbalance

Background

Long non‐coding RNA plasmacytoma variant translocation 1 (lnc‐PVT1) exacerbates inflammation and induces T helper (Th) 1/Th2 imbalance in allergic diseases, but its clinical role in allergic rhinitis (AR) remains unclear. Hence, we conducted this study to compare lnc‐PVT1 expression among AR children, disease controls (DCs), and health controls (HCs), aiming to investigate its clinical application in AR children.

Methods

Sixty AR children, 30 DCs, and 30 HCs were enrolled in the study, and then, their lnc‐PVT1 expression in peripheral blood mononuclear cell was detected. Serum interferon‐gamma (IFN‐γ), interleukin 10 (IL‐10), Th1, and Th2 cells in AR children were also analyzed. Besides, lnc‐PVT1 was also detected at Week (W)4 after treatment in AR patients.

Results

Lnc‐PVT1 was upregulated in AR children compared with DCs and HCs (both p < 0.001). Lnc‐PVT1 was positively related to nasal rhinorrhea score, itching score, congestion score, and total nasal symptom score (TNSS) in AR children (all p < 0.050), instead of sneezing score (p = 0.115). Lnc‐PVT1 negatively associated with Th1 cells in AR children (p = 0.028) also exhibited a negative correlation trend with IFN‐γ (but without statistical significance) (p = 0.065). Differently, lnc‐PVT1 was positively related to Th2 cells (p = 0.012) and IL‐10 (p = 0.021) in AR children. Besides, lnc‐PVT1 and TNSS were reduced at W4 after treatment in AR children (both p < 0.001); notably, lnc‐PVT1 expression decline was correlated with TNSS decline during treatment (p = 0.013).

Conclusion

Lnc‐PVT1 works as a biomarker, whose aberrant expression is related to disease severity, Th1/Th2 imbalance, and its decrement can reflect treatment outcome in AR children.

Construction of a lncRNA-miRNA-mRNA network to determine the key regulators of the Th1/Th2 imbalance in multiple sclerosis

Aim: The exact epigenetic mechanisms that determine the balance of T helper (Th)1 and Th2 cells and autoimmune responses in multiple sclerosis (MS) remain unclear. We aim to clarify these. Methods: A combination of bioinformatics analysis and molecular evaluations was utilized to identify master hub genes. Results: A competitive endogenous RNA network containing six long noncoding RNAs (lncRNAs), 21 miRNAs and 86 mRNAs was provided through enrichment analysis and a protein-protein interaction network. NEAT1 and MALAT1 were found as differentially expressed lncRNAs using Gene Expression Omnibus (GSE21942). Quantitative real-time PCR results demonstrate dysregulation in the RUNX3 (a regulator of Th1/Th2 balance), GATA3 and TBX21, as well as miR-544a and miR-210-3p (which directly target RUNX3). ELISA also confirmed an imbalance in IFN-γ (Th1)/IL-4 (Th2) in MS patients. Conclusion: Our findings introduce novel biomarkers leading to Th1/Th2 imbalance in MS.

Salidroside Mitigates Airway Inflammation in Asthmatic Mice via the AMPK/Akt/GSK3β Signaling Pathway

INTRODUCTION

This study aimed to explore the effects and mechanisms of salidroside (SAL) in airway inflammation in asthmatic mice.

METHODS

Mice were sensitized with ovalbumin (OVA) to establish an asthma model. They were divided into the control group, OVA group, SAL low-dose group (SAL-L), SAL high-dose group (SAL-H), and dexamethasone (DXM) group. The airway reactivity of the mice was measured, and the total cells, neutrophils, eosinophils, and lymphocytes were counted, respectively. The levels of IL-4, IL-5, IL-13, and IFN-γ in bronchoalveolar lavage fluid (BALF) were detected by ELISA. Immunohistochemistry was used to detect the expression levels of p-AMPK, p-Akt, and p-GSK3β. Western blot was used to detect cytokine levels in lung tissue and p-AMPK, p-Akt, and p-GSK3β levels in LPS-induced 16HBE cells.

RESULTS

The airway hyperresponsiveness of asthmatic mice in the SAL-H group decreased (p < 0.05), and the total number of cells, neutrophils, eosinophils, and lymphocytes decreased significantly (p < 0.05). In addition, the airways of mice showed airway inflammatory infiltration and goblet cell proliferation, and the corresponding cellular inflammatory factors IL-4, IL-5, and IL-13 were significantly decreased. However, the expression of IFN-γ in BALF and lung tissues was increased (p < 0.05). Moreover, after the mice were treated with SAL, the phosphorylation level of AMPK was significantly increased, which further reduced the phosphorylation levels of Akt and GSK3β (p < 0.05). Both SAL and AMPK inhibitors exerted effects on LPS-induced 16HBE cells, consistent with in vivo results.

CONCLUSION

SAL can inhibit bronchial hyperresponsiveness and reduce tracheal inflammation by increasing AMPK phosphorylation and inhibiting Akt and GSK3β signaling pathways.

Key Gene and Functional Pathways Identified in Unexplained Recurrent Spontaneous Abortion Using Targeted RNA Sequencing and Clinical Analysis

Identifying the mechanisms underlying unexplained recurrent spontaneous abortion (URSA) can help develop effective treatments. This study provides novel insights into the biological characteristics and related pathways of differentially expressed genes (DEGs) in URSA. Nineteen patients with URSA and three healthy fertile women with regular menstruation (control group) were recruited. RNA was extracted from the two groups to determine the differential expression of immunoregulatory gene sequences. Gene ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analyses were used to identify the biological functions and pathways of the identified DEGs. A protein-protein interaction (PPI) network was constructed using the STRING database. Furthermore, qRT-PCR and ELISA were performed to validate the differential expression of the hub genes. We also explored the regulatory mechanism of Th1/Th2 imbalance. A total of 99 DEGs were identified, comprising 94 upregulated and five downregulated genes. Through GO analysis, nine immune cell function-related clusters were selected, and genes with significant differential expression were primarily enriched in eight immune regulatory functions related to the KEGG signalling pathway. Subsequently, five hub genes (TLR2, CXCL8, IFNG, IL2RA, and ITGAX) were identified using Cytoscape software; qRT-PCR confirmed the differential expression among the hub genes, whereas ELISA revealed a significant difference in extracellular IFN-γ and IL-8 levels. The levels of Th1 (IFN-γ) and the Th1/Th2 ratio were higher in the peripheral blood of URSA patients than in control group patients. These findings suggest that the occurrence of URSA may be associated with the abnormal expression of some specific immunoregulatory genes involved in T-cell activation and differentiation. Among the identified DEGs, IFNG may play a key role in regulating maternal immune response. Although further validation is required, our data provide an important theoretical basis for elucidating the pathogenesis of recurrent spontaneous abortion.

Th1/Th2 imbalance and heat shock protein mediated inflammatory damage triggered by manganese via activating NF-κB pathway in chicken nervous system in vivo and in vitro

Manganese (Mn) is a ubiquitous heavy metal pollutant in environment, and excess Mn can damage nervous system of humans and animals. However, molecular mechanism of Mn-induced poultry neurotoxicity on inflammatory injury is still not fully clear. Thus, the purpose of the conducted research was to explore molecular mechanism of inflammatory injury caused by Mn in chicken nervous system. Two Mn poisoning models were established in vivo and in vitro. One hundred and eighty chickens were randomly separated into four groups. One control group was raised drinking water and standard diet. Three Mn groups were raised drinking water, and the standard diet supplemented with three different concentrations of MnCl2 ∙ 4H2O. There were 45 birds and 3 replicates in each group. Neurocytes from chicken embryos were cultured in mediums without and with six different concentrations of MnCl2 ∙ 4H2O in vitro. Our experiments showed that excess Mn caused cerebral histomorphological structure alternations and damage, and increased the expressions (P < 0.05) of inflammation-related factor NF-κB, TNF-α, iNOS, COX-2, and PTGEs in vivo and in vitro, meaning that excess Mn caused inflammatory damage and inflammatory response in chicken nervous system. Moreover, there were an upregulated IFN-γ mRNA expression and a downregulated IL-4 mRNA expression (P < 0.05) in bird cerebra and embryonic neurocytes after exposure to Mn, indicating that Mn exposure caused Th1/Th2 imbalance and immunosuppression. Additionally, in our research, the elevation (P < 0.05) of five HSPs (HSP27, HSP40, HSP60, HSP70, and HSP90) was found, suggesting that HSPs participated molecular mechanism of Mn stress. In addition, the inflammatory toxicity of Mn to chicken nervous system was time- and dose-dependent. Taken all together, our findings indicated that Th1/Th2 imbalance and HSPs mediated Mn-caused inflammatory injury via NF-κB pathway in chicken nervous system in vivo and in vitro.

Cadmium induces endoplasmic reticulum stress-mediated apoptosis in pig pancreas via the increase of Th1 cells

Cadmium (Cd), an environmental pollutant, causes several adverse reactions in animals. High dose of Cd has serious cytotoxicities, including the induction of programmed cell necrosis, autophagy and apoptosis, which has aroused wide public concern. The balance of cytokine network is affected by Th1/Th2 balance which is closely related to immune response and the occurrence, development, treatment and outcome of various diseases. Cd can induce severe apoptosis, but the relationship between Cd induced apoptosis and Th1/Th2 balance has not been clarified. In this study, we established a pig Cd poisoning model, exposing to CdCl₂ for 40 days (20 mg Cd/kg diet). Firstly, deviation of Th1/Th2 balance was observed by fluorescence staining, and apoptosis was observed by TUNEL staining. Then, real-time fluorescence quantitative analysis and Western blot were used to detect the expression of related proteins. The results show that Cd can interfere with the balance of Th1/Th2 and shift the balance towards Th1. In addition, through the experiments, we found that Cd exposure can increase the expression of glucose-regulated protein 94 (GRP94) and glucose-regulated protein 78 (GRP78), marker proteins of unfolded protein response (UPR). Cd exposure can increase the expression of pancreatic endoplasmic reticulum kinase (PERK), CCAAT-enhancer-binding protein homologous protein (CHOP), inositol-requiring enzyme 1 (IRE-1), activating transcription factor 6 (ATF-6), cysteinyl aspartate specific proteinase (Caspase12), indicating the three branches (ATF6, PERK and IRE-1) of endoplasmic reticulum stress (ER-stress) were activated. Moreover, we found that the expression of pro-apoptosis genes in the downstream pathway of ER-stress increased. In summary, our results indicated that Cd exposure upregulated the expression of pro-apoptosis related genes and caused apoptosis via the activation of the ER-stress signaling pathways in pancreas cells. And these negative effects were correlated with the equilibrium drift of Th1/Th2, increase in the expression and secretion of Th1 cytokines.

Germacrone alleviates collagen-induced arthritis via regulating Th1/Th2 balance and NF-κB activation

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease. The imbalance of T helper type 1 (Th1) and Th2 immune responses contributes to the pathogenesis of this disease. Germacrone is a major bioactive component isolated from Rhizoma Curcuma with multiple bioactivities including anti-inflammation. However, the role and mechanism of germacrone in RA are still unknown. Collagen-induced arthritis (CIA) model was established in male DBA/1 J mice by two immunizations with chicken collagen II. Germacrone was orally administered once per day starting on the day of second immunization for 3 weeks. Arthritis scoring was evaluated every 3 days after second immunization. H&E staining was used for histopathological examination. Levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-4 in serum and synovial tissues of mice were detected by ELISA. Th1 and Th2 cell percentage in mouse spleens was analyzed by flow cytometry. IκB and phosphorylation of NF-κB p65 (p-p65) expression in mouse synovial tissues was assayed by Western blot. We found germacrone treatment significantly reduced arthritis score and inflammation in CIA mice. Levels of TNF-α and IFN-γ were elevated, and IL-4 reduced, in the serum and synovial tissues of CIA mice. Germacrone partially reversed levels of these cytokines. Moreover, germacrone decreased the ratio of Th1 to Th2 cells in mouse spleens. Additionally, germacrone remarkably enhanced IκB expression, but suppressed p-p65 level in CIA mice. Taken together, these results suggest that germacrone alleviated the progression of arthritis that might be related to the regulation of Th1/Th2 balance and inactivation of NF-κB pathway.

Tuberculosis patients display a high proportion of CD8+ T cells with a high cytotoxic potential

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) and remains a major cause of morbidity and mortality worldwide. In the host's immune response system, T cells play a critical role in mediating protection against Mtb infection, but the role of CD8⁺ T cells is still controversial. We evaluated the phenotypical characterization and cytotoxic ability of CD8⁺ T cells by flow cytometry‐based assay. Cytokine levels in serum were measured by multiplex cytokine assay. Our data show that cells from TB patients have an increased percentage of peripheral blood CD8⁺αβ⁺ T (p = 0.02) and CD56⁺CD8⁺ T (p = 0.02) and a decreased frequency of NKG2D⁺CD8⁺ T (p = 0.02) compared with healthy donors. Unlike CD8⁺ T cells from healthy donors, CD8⁺ T cells from TB patients exhibit greater cytotoxicity, mediated by HLA class I molecules, on autologous monocytes in the presence of mycobacterial antigens (p = 0.005). Finally, TB patients have a proinflammatory profile characterized by serum high level of TNF‐α (p = 0.02) and IL‐8 (p = 0.0001), but, interestingly, IL‐4 (p = 0.002) was also increased compared with healthy donors. Our data show evidence regarding the highly cytotoxic status of CD8⁺ T cells in Mtb infection. These cytotoxic cells restricted to HLA‐A, B, and C could be used to optimize strategies for designing new TB vaccines or for identifying markers of disease progression.

Tumor-derived MDSCs inhibit airway remodeling in asthmatic mice through regulating IL-10 and IL-12

Myeloid-derived suppressor cells (MDSCs), a group of newly discovered and heterogeneous myeloid-derived immunosuppressive cells, play an important role in the progress of asthma, however, the specific mechanism is still largely unclear. Our previous study has indicated that during the onset of asthma, the accumulation of MDSCs and the level of serum interleukin (IL)-10 increased, while the level of IL-12 decreased. The present study aimed to investigate whether tumor-derived MDSCs could inhibit airway remodeling in asthmatic mice through regulating IL-10 and IL-12 secretion. To perform our investigation, we established a mouse model of breast cancer, and the extracted MDSCs from breast caner mouse model were injected into a mouse model of asthma induced by ovalbumin (OVA). Then, asthmatic airway remodeling of mice was analyzed and the levels of IL-10 and IL-12 in the serum and bronchoalveolar lavage fluid (BALF) of mice were detected. In addition, the correlation of MDSCs with the levels of IL-10 and IL-12 in the transplantation group was analyzed. The transplantation of tumor-derived MDSCs into asthmatic mice significantly improved airway remodeling, decreased MDSCs and the expression of IL-10, and significantly increased the expression of IL-12. Besides, we confirmed that IL-10 was positively correlated with MDSCs, while IL-12 was negatively correlated with MDSCs. The results indicated that tumor-derived MDSCs could reduce IL-10 level, increase the level of IL-12, and thus correct the Th1/Th2 imbalance in asthmatic mice. In summary, our results revealed that tumor-derived MDSCs could serve as a potential novel target for asthma therapy.

TARC expression in the circulation and cutaneous granulomas correlates with disease severity and indicates Th2-mediated progression in patients with sarcoidosis

BACKGROUND

Sarcoidosis is a systemic disorder characterized by the accumulation of lymphocytes and monocyte/macrophage lineage cells that results in the formation of non-caseating granulomas. Thymus- and activation-regulated chemokine (TARC)/CCL17 is an important chemokine in the amplification of Th2 responses, which are achieved by recruiting CCR4-expressing CD4⁺ T lymphocytes. TARC concentrations are known to increase in the serum of sarcoidosis patients; however, its role in the assessment of severity and prognosis of sarcoidosis remains unknown. The objective of this study is to elucidate the role of TARC in sarcoidosis by investigating its expression in peripheral blood and at inflammatory sites. We also examined its relationship with clinical features.

METHODS

Serum levels of TARC, soluble interleukin 2 receptor, angiotensin-converting enzyme, and lysozyme were measured in 82 sarcoidosis patients. The Th1 and Th2 balance in circulating CD4⁺ T cells was evaluated by flow cytometry. The immunohistochemical staining of TARC and CCR4 was performed in order to identify the source of TARC in affected skin tissues.

RESULTS

TARC serum levels were elevated in 78% of patients and correlated with disease severity. The percentage of CCR4⁺ cells and the CCR4⁺/CXCR3⁺ cell ratios were significantly higher in sarcoidosis patients than in normal subjects (P = 0.002 and P = 0.015, respectively). Moreover, TARC was expressed by monocyte/macrophage lineage cells within granulomas. The abundancy as well as distribution of TARC staining correlated with its serum levels.

CONCLUSIONS

The present results suggest that elevations in TARC drive an imbalanced Th2- weighted immune reaction and might facilitate prolonged inflammatory reactions in sarcoidosis.

Down-regulation of Notch signaling pathway reverses the Th1/Th2 imbalance in tuberculosis patients

Th1/Th2 imbalance to Th2 is of significance in the peripheral immune responses in Tuberculosis (TB) development. However, the mechanisms for Th1/Th2 imbalance are still not well determined. Notch signaling pathway is involved in the peripheral T cell activation and effector cell differentiation. However, whether it affects Th1/Th2 imbalance in TB patients is still not known. Here, we used γ-secretase inhibitor (DAPT) to treat the peripheral blood mononuclear cells (PBMCs) from healthy people or individuals with latent or active TB infection in vitro, respectively. Then, the Th1/Th2 ratios were determined by flow cytometry, and cytokines of IFN-γ, IL-4, IL-10 in the culture supernatant were measured by CBA method. The Notch signal pathway associated proteins Hes1, GATA3 and T-bet were quantitated by real-time PCR or immunoblotting. Our results showed that DAPT effectively inhibited the protein level of Hes1. In TB patients, the Th2 ratio increased in the PBMCs, alone with the high expression of GATA3 and IL-4, resulting in the high ratios of Th2/Th1 and GATA3/T-bet in TB patients. However, Th2 cells ratio decreased after blocking the Notch signaling pathway by DAPT and the Th2/Th1 ratio in TB patients were DAPT dose-dependent, accompanied by the decrease of IL-4 and GATA3. But, its influence on Th1 ratio and Th1 related T-bet and IFN-γ levels were not significant. In conclusion, our results suggest that blocking Notch signaling by DAPT could inhibit Th2 responses and restore Th1/Th2 imbalance in TB patients.

spv locus aggravates Salmonella infection of zebrafish adult by inducing Th1/Th2 shift to Th2 polarization

Salmonella enterica serovar typhimurium (S. typhimurium) are facultative intracellular enteric pathogens causing disease with a broad range of hosts. It was known that Th1-type cytokines such as IFN-γ, IL-12, and TNF-α etc. could induce protective immunity against intracellular pathogens, while Th2-type cytokines such as IL-4, IL-10, and IL-13 etc. are proved to help pathogens survive inside hosts and cause severe infection. One of the critical virulence factor attributes to the pathogenesis of S. typhimurium is Salmonella plasmid virulence genes (spv). Until now, the interaction between spv locus and the predictable generation of Th1 or Th2 immune responses to Salmonella has not been identified. In this study, zebrafish adults were employed to explore the effect of spv locus on Salmonella pathogenesis as well as host adaptive immune responses especially shift of Th1/Th2 balance. The pathological changes of intestines and livers in zebrafish were observed by hematoxylin-eosin (HE) staining and electron microscopy. Levels of the transcription factors of Th1 (Tbx21) and Th2 (GATA3) were measured by real-time quantitative PCR (RT-qPCR). Expression of cytokines were determined by using RT-qPCR and ELISA, respectively. Results showed that spv operon aggravates damage of zebrafish. Furthermore, it demonstrated that spv locus could inhibit the transcription of tbx21 gene and suppress the expression of cytokines IFN-γ, IL-12 and TNF-α. On the contrary, the transcription of gata3 gene could be promoted and the expression of cytokines IL-4, IL-10 and IL-13 were enhanced by spv locus. Taken together, our data revealed that spv locus could aggravate Salmonella infection of zebrafish adult by inducing an imbalance of Th1/Th2 immune response and resulting in a detrimental Th2 bias of host.

Citrus tachibana Leaves Ethanol Extract Alleviates Airway Inflammation by the Modulation of Th1/Th2 Imbalance via Inhibiting NF-κB Signaling and Histamine Secretion in a Mouse Model of Allergic Asthma

Asthma is a chronic inflammatory disease of bronchial airway, which is characterized by chronic airway inflammation, airway edema, goblet cell hyperplasia, the aberrant production of the Th2 cytokines, and eosinophil infiltration in the lungs. In this study, the therapeutic effect and the underlying mechanism of Citrus tachibana leaves ethanol extract (CTLE) in the ovalbumin (OVA)-induced allergic asthma and compound 48/80-induced anaphylaxis were investigated. Oral administration of CTLE inhibited OVA-induced asthmatic response by reducing airway inflammation, OVA-specific IgE and IgG1 levels, and increasing OVA-specific IgG2a levels. CTLE restored Th1/Th2 balance through an increase in Th2 cytokines tumor necrosis factor-α, interleukin (IL)-4, and IL-6 and decreases in Th1 cytokines interferon-γ and IL-12. Furthermore, CTLE inhibited the total level of NF-κB and the phosphorylation of IκB-α and NF-κB by OVA. In addition, CTLE dose-dependently inhibited compound 48/80-induced anaphylaxis via blocking histamine secretion from mast cells. The anti-inflammatory mechanism of CTLE may involve the modulation of Th1/Th2 imbalance via inhibiting the NF-κB signaling and histamine secretion. Taken together, we suggest that CTLE could be used as a therapeutic agent for patients with Th2-mediated or histamine-mediated allergic asthma.

Altered Th1/Th2 commitment contributes to lung senescence in CXCR3-deficient mice

Aging is an inevitable process associated with immune imbalance, which is characterized by a progressive functional decline in major organs, including lung. However, effects of altered Th1/Th2 commitment on lung senescence are largely unknown. To examine effects of altered Th1/Th2 balance on lung aging, we measured proportions of Th1 and Th2 cells and expression of cytokines, chemokines, collagen deposition and other relevant physiological and pathological parameters in 2- and 20-months-old (mo) CXCR3-deficient (CXCR3(-/-)) C57BL/6J mice compared with wild-type (WT) mice. There was a significant weight-loss observed in 20-mo CXCR3(-/-) mice compared with the same aged WT group. Although lung function and structure changed with age in both groups, central airway resistance (Rn), tissue elastance (H) and damping (G) were significantly lower in 20-mo CXCR3(-/-) mice than those of WT mice. In contrast, the whole lung volume (V(L)), the mean linear intercept length of alveolar (L(m)), and the total lung collagen content were significantly elevated in 20-mo CXCR3(-/-) mice. With aging, the lungs of WT mice had typical Th1-type status (increased population of Th1 cells and concentrations of cytokine IFN-γ and CXCR3 ligands) while CXCR3(-/-) mice showed Th2-type polarization (decreased proportion of Th1 cells and concentrations of CXCR3 ligands but increased level of IL-4). Our data suggest that Immunosenescence is associated with lung aging, and that altered Th1/Th2 imbalance favors Th2 predominance in CXCR3(-/-) mice, which contributes to the process of accelerated lung aging in this model.