Th17/Treg immunoregulation and implications in treatment of sulfur mustard gas-induced lung diseases

The immune cells profiles of individuals with sulfur mustard-induced serious long-term respiratory complications

Sulfur mustard (SM) induced pulmonary disorder is a heterogeneous disease characterized by uncontrolled inflammatory immune responses. In this cross-sectional study carried out in Isfahan-Iran, our objective was to thoroughly evaluate the clinical health and peripheral blood leukocyte profiles of adult veterans exposed to SM 25-30 years. In total, 361 people were studied in two groups, 287 chemical veterans with pulmonary complications and 64 healthy individuals as a control group. The participants underwent a comprehensive lung evaluation, including physical examination, Pulmonary Assessment, and Spirometry Assessment. Blood samples were collected in EDTA-treated tubes and flow cytometry analysis was employed to study different population of leukocytes including lymphocytes, monocytes, and natural killer cells. In our results, SM-exposed patients showed a significant increase in mean WBC and lymphocyte absolute count. However, the frequency of CD14+ monocytes and CD3+ CD4+ CD25+Hi as regulatory T cell subsets significantly decreased in SM-exposed patients. In addition, there was a negative correlation between CD45+ CD14+ cells and residual volume (RV). The population of NK cells showed a negative correlation with forced expiratory volume in the first one second to the forced vital capacity (FEV1/FVC). On the other hand, the percentage of CD19+ B cells positively correlated with Mid-maximum expiratory flow (MMEF) rate, ppm Reading, Carboxyhemoglobin (CoHb), and FEV1, and it was negatively correlated with airway resistance (RAW). Evaluation of CD3+ CD8+ cytotoxic T cells frequency negatively correlated with CoHb, ppm Reading, total lung capacity (TLC), and RV. Furthermore, the count of CD3+ CD4+ T cells demonstrated a negative correlation with TLC. The percentage of CD3+ CD4+ CD25+ cells was positively correlated with ppm reading and CoHb. Overall, our findings revealed modifications in total lymphocyte dynamics and a decrease in the percentage and absolute number of regulatory T cells, compromising the regulatory arm of the immune system to modulate SM-induced inflammatory damages.

Mogroside V protects lipopolysaccharides-induced lung inflammation chicken via suppressing inflammation mediated by the Th17 through the gut-lung axis

Lipopolysaccharide (LPS) exposure triggers pulmonary inflammation, leading to compromised lung function in broiler. As amplified by policy restrictions on antibiotic usage, seeking antibiotic alternatives has become imperative. Mogroside V (MGV) has been reported to have a beneficial role in livestock and poultry production due to its remarkable antiinflammatory effects. Despite evidence showcasing MGV's efficacy against LPS-triggered lung inflammation, its precise mechanism of action remains elusive. In this study, we transplanted normal fecal microbiota (CF), fecal microbiota modified by MGV (MF), and sterile fecal filtrate (MS) into broiler with LPS-induced pneumonia. The results showed that through fecal microbiota transplantation (FMT), transplanting MGV-induced microbial populations significantly mitigated tissue damage induced by LPS and enhanced the mRNA level of pulmonary tight junction proteins and mucoprotein (P < 0.01). The expression levels of RORα (P < 0.001), Foxp3 (P < 0.01), and PD-L1 (P < 0.01) were significantly increased in the MF group than CF group. The concentrations of IL-6 and IL-17 in broilers lung tissue of MF group were lower than those in broilers of CF group (P < 0.05). Furthermore, the concentration of TGF-β in broilers serum of MS and MF groups was higher than those in broilers of CF group (P < 0.05). Microbial community analysis demonstrated that at genus level, the harmful bacterial populations Escherichia-Shigella and Helicobacter following FMT treatment were significantly reduced in MF group (P < 0.05), potentially mediating its protective effects. Compared with CF group, valerate content and FFAR2 mRNA expression levels in MF group were significantly increased (P < 0.05). The study suggests that MGV via the gut-lung axis, attenuates Th17-mediated inflammation, offering promise as a therapeutic strategy against LPS-induced lung inflammation in chickens.

Insight into the role of macrophages in periodontitis restoration and development

Periodontitis is one of the chronic diseases that have the greatest impact on human health, and it is associated with several other chronic diseases. Tissue damage associated with periodontitis is often connected with immune response. Immune cells are a crucial component of the human immune system and are directly involved in periodontitis during the inflammatory phase of the disease. Macrophages, as a key component of the immune system, are responsible for defence, antigen presentation and phagocytosis in healthy tissue. They are also closely linked to the development and resolution of periodontitis, through mechanisms such as macrophage polarization, pattern recognition receptors recognition, efferocytosis, and Specialized Pro-resolving Mediators (SPMs) production. Additionally, apoptosis and autophagy are also known to play a role in the recovery of periodontitis. This review aims to investigate the aforementioned mechanisms in more detail and identify novel therapeutic approaches for periodontitis.

The Complex Dysregulations of CD4 T Cell Subtypes in HIV Infection

Human immunodeficiency virus (HIV) infection remains an important global public health problem. About 40 million people are infected with HIV, and this infection caused about 630,000 deaths in 2022. The hallmark of HIV infection is the depletion of CD4+ T helper lymphocytes (Th cells). There are at least seven different Th subtypes, and not all are the main targets of HIV. Moreover, the effect of the virus in a specific subtype can be completely different from that of the others. Although the most compromised Th subtype in HIV infection is Th17, HIV can induce important dysregulations in other subtypes, such as follicular Th (Tfh) cells and regulatory Th cells (Treg cells or Tregs). Several studies have shown that HIV can induce an increase in the immunosuppressive activity of Tregs without causing a significant reduction in their numbers, at least in the early phase of infection. The increased activity of this Th subtype seems to play an important role in determining the immunodeficiency status of HIV-infected patients, and Tregs may represent a new target for innovative anti-HIV therapies, including the so-called "Kick and Kill" therapeutic method whose goal is the complete elimination of the virus and the healing of HIV infection. In this review, we report the most important findings on the effects of HIV on different CD4+ T cell subtypes, the molecular mechanisms by which the virus impairs the functions of these cells, and the implications for new anti-HIV therapeutic strategies.

Unraveling the hepatic stellate cells mediated mechanisms in aging's influence on liver fibrosis

Aging enhances numerous processes that compromise homeostasis and pathophysiological processes. Among these, activated HSCs play a pivotal role in advancing liver fibrosis. This research delved into how aging impacts liver fibrosis mechanisms. The study involved 32 albino rats categorized into four groups: Group I (young controls), Group II (young with liver fibrosis), Group III (old controls), and Group IV (old with liver fibrosis). Various parameters including serum ALT, adiponectin, leptin, and cholesterol levels were evaluated. Histopathological analysis was performed, alongside assessments of TGF-β, FOXP3, and CD133 gene expressions. Markers of fibrosis and apoptosis were the highest in group IV. Adiponectin levels significantly decreased in Group IV compared to all other groups except Group II, while cholesterol levels were significantly higher in liver fibrosis groups than their respective control groups. Group III displayed high hepatic expression of desmin, α-SMA, GFAP and TGF- β and in contrast to Group I. Increased TGF-β and FOXP3 gene expressions were observed in Group IV relative to Group II, while CD133 gene expression decreased in Group IV compared to Group II. In conclusion, aging modulates immune responses, impairs regenerative capacities via HSC activation, and influences adipokine and cholesterol levels, elevating the susceptibility to liver fibrosis.

Regulatory T cells (Tregs) in liver fibrosis

The ability of the human liver to both synthesize extracellular matrix(ECM), as well as regulate fibrogenesis, are integral functions to maintaining homoeostasis. Chronic liver injury stimulates fibrogenesis in response to the imbalance between ECM accumulation and fibrosis resolution. Liver disease that induces fibrogenesis is associated with multiple risk factors like hepatitis infection, schistosomiasis, alcohol, certain drugs, toxicants and emerging aetiology like diabetes and obesity. The activation of hepatic stellate cells (HSCs), whose function is to generate and accumulate ECM, is a pivotal event in liver fibrosis. Simultaneously, HSCs selectively promote regulatory T-cells (Tregs) in an interleukin-2-dependent pattern that displays a dual relationship. On the one hand, Tregs can protect HSCs from NK cell attack, while on the other hand, they demonstrate an inhibitory effect on HSCs. This paper reviews the dual role of Tregs in liver fibrogenesis which includes its promotion of immunosuppression, as well as its activation of fibrosis. In particular, the balance between Tregs and the Th17 cell population, which produce interleukin (IL)-17 and IL-22, is explored to demonstrate their key role in maintaining homoeostasis and immunoregulation. The contradictory roles of Tregs in liver fibrosis in different immune microenvironments and molecular pathways need to be better understood if they are to be deployed to manage this disease.

Estrogen Protects against Renal Ischemia-Reperfusion Injury by Regulating Th17/Treg Cell Immune Balance

Inflammation is a critical mediator of renal ischemia-reperfusion (I/R) injury (IRI), and T lymphocytes exert a key role in the renal IRI-induced inflammation. Connexin 43 (Cx43) is related to the maintenance of T lymphocyte homeostasis. Various preclinical researches have reported that estrogen is a renoprotective agent based on its anti-inflammatory potential. The present research is aimed at studying the role of T lymphocytes activated by Cx43 in 17β-estradiol-mediated protection against renal IRI. Female rats were classified into six groups: control rats, I/R rats, ovariectomized rats, ovariectomized I/R rats, and ovariectomized rats treated with 17β-estradiol or gap27. Levels of serum creatinine (Scr) and blood urea nitrogen (BUN) and Paller scoring were dramatically increased in I/R rats, especially in ovariectomized rats. By contrast, these indicators were markedly decreased by administering estradiol or gap27. Immunofluorescence staining revealed that CD4⁺ T cells infiltrated kidney tissues in the early stage of IRI. In both peripheral blood and renal tissue, the proportion of CD3⁺CD4⁺ T cells and ratio of CD4⁺ to CD8⁺ were high in I/R rats, especially in ovariectomized rats. The proportion of CD3⁺CD8⁺ T cells was low in peripheral blood but high in renal tissues. Administration of estrogen or Gap27 reversed these effects. IL-17 levels in both serum and tissue homogenate were significantly increased in ovariectomized rats subjected to I/R but significantly decreased in estrogen or gap 27 treated rats. The opposite trend was observed for IL-10 levels. Correlation analysis demonstrated that IL-17 was correlated positively with BUN, Scr, and Paller scores, while IL-10 was negatively correlated with these indicators. Western blot showed that Cx43 expression was markedly increased in the peripheral blood T lymphocytes of I/R rats, especially ovariectomized rats. After intervention with estrogen and gap27, Cx43 expression was significantly downregulated. These findings indicate that Cx43 may participate in the regulation of Th17/Treg balance by estrogen against renal IRI.

Emerging Insights into the Impact of Air Pollution on Immune-Mediated Asthma Pathogenesis

PURPOSE OF REVIEW

Increases in ambient levels of air pollutants have been linked to lung inflammation and remodeling, processes that lead to the development and exacerbation of allergic asthma. Conventional research has focused on the role of CD4+ T helper 2 (TH2) cells in the pathogenesis of air pollution-induced asthma. However, much work in the past decade has uncovered an array of air pollution-induced non-TH2 immune mechanisms that contribute to allergic airway inflammation and disease.

RECENT FINDINGS

In this article, we review current research demonstrating the connection between common air pollutants and their downstream effects on non-TH2 immune responses emerging as key players in asthma, including PRRs, ILCs, and non-TH2 T cell subsets. We also discuss the proposed mechanisms by which air pollution increases immune-mediated asthma risk, including pre-existing genetic risk, epigenetic alterations in immune cells, and perturbation of the composition and function of the lung and gut microbiomes. Together, these studies reveal the multifaceted impacts of various air pollutants on innate and adaptive immune functions via genetic, epigenetic, and microbiome-based mechanisms that facilitate the induction and worsening of asthma.

Observation of the Effect of Singulair Combined With Ketotifen in the Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease With Airway Hyperresponsiveness and Its Influence on Th17/Treg

Objective

To investigate the effect of montelukast sodium (singulair) combined with ketotifen fumarate on the acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with airway hyperresponsiveness (AHR) and its effect on helper T cells 17 (Th17)/regulator T cells (Treg).

Methods

168 patients with AECOPD and AHR diagnosed in our hospital from February 2018 to December 2019 were selected, and divided into the observation group (n = 84) and the control group (n = 84). Both groups were given anti infection, bronchodilator, glucocorticoid, phosphodiesterase inhibitor, cough and expectorant. The observation group was additionally treated with singulair tablets and ketotifen tablets for 14 days. The curative effect were observed after treatment. The first second forced expiratory volume (FEV1), forced vital capacity (FVC) and FEV1 as percentage of predicted value (FEV1% pred), blood oxygen pressure (PaO₂) and blood carbon dioxide pressure (PaCO₂), high-sensitivity C-reactive protein (hs-CRP) and procalcitonin (PCT), Th17 and Treg levels were measured in both groups before and after treatment.

Results

Compared with the control group, the total effective rate after treatment in the observation group was increased (94.05 vs. 75.00%, P < 0.05). Compared with before treatment, the FEV1, FVC and FEV1%pred levels of the two groups of patients after treatment were increased (P < 0.05). Compared with the control group, the FEV1, FVC and FEV1%pred levels of the observation group were increased after treatment (P < 0.05). Compared with before treatment, the PaCO2, hs-CRP and PCT levels of the two groups of patients were reduced after treatment, and PaO2 levels were increased (P < 0.05). Compared with the control group, the PaCO2, hs-CRP and PCT levels in the observation group were reduced after treatment, and the PaO2 level was increased (P < 0.05). Compared with before treatment, Th17 and Th17/Treg levels of the two groups of patients were reduced after treatment, and Treg levels were increased (P < 0.05). Compared with the control group, the Th17 and Th17/Treg levels of the observation group were reduced after treatment, and the Treg levels was increased (P < 0.05).

Conclusion

Singulair combined with ketotifen in the treatment of patients with AECOPD combined with AHR can significantly improve the efficacy, improve lung function, reduce inflammatory response, and improve the balance of Th17/Treg, effectively controlling the disease.

Diacetyl Vapor Inhalation Induces Mixed, Granulocytic Lung Inflammation with Increased CD4+CD25+ T Cells in the Rat

Diacetyl (DA) is a highly reactive alpha diketone associated with flavoring-related lung disease. In rodents, acute DA vapor exposure can initiate an airway-centric, inflammatory response. However, this immune response has yet to be fully characterized in the context of flavoring-related lung disease progression. The following studies were designed to characterize the different T cell populations within the lung following repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor for 5 consecutive days × 6 h/day. Lung tissue and bronchoalveolar lavage fluid (BALF) were analyzed for changes in histology by H&E and Trichrome stain, T cell markers by flow cytometry, total BALF cell counts and differentials, BALF IL17a and total protein immediately, 1 and 2 weeks post-exposure. Lung histology and BALF cell composition demonstrated mixed, granulocytic lung inflammation with bronchial lymphoid aggregates at all time points in DA-exposed lungs compared to air controls. While no significant change was seen in percent lung CD3+, CD4+, or CD8+ T cells, a significant increase in lung CD4+CD25+ T cells developed at 1 week that persisted at 2 weeks post-exposure. Further characterization of this CD4+CD25+ T cell population identified Foxp3+ T cells at 1 week that failed to persist at 2 weeks. Conversely, BALF IL-17a increased significantly at 2 weeks in DA-exposed rats compared to air controls. Lung CD4+CD25+ T cells and BALF IL17a correlated directly with BALF total protein and inversely with rat oxygen saturations. Repetitive DA vapor exposure at occupationally relevant concentrations induced mixed, granulocytic lung inflammation with increased CD4+CD25+ T cells in the rat lung.

Regulatory Effects of Andrographolide on Lung Tissue Inflammation and Th17/Treg in Rats with Chronic Obstructive Pulmonary Disease Induced by Smoking and Lipopolysaccharide

The pathogenesis of Chronic obstructive pulmonary disease (COPD) is complex, and lung tissue inflammation and Th17/Treg imbalance are the key factors causing lung dysfunction. We constructed a rat COPD model induced by smoking and lipopolysaccharide to explore andrographolide’s regulation on lung inflammation and Th17/Treg in COPD rats. By contrast, the study found that normal rats, COPD rats forced expiratory volume of 0.3 seconds (FEV0.3), FEV0.3/forced vital capacity (FVC), and peak expiratory flow (PEF) levels decreased. In addition, the levels of IL-8, TNF-α, IL-17, and IL-6 in alveolar lavage fluid increased, and the level of IL-10 decreased. Concurrently, the total number of white blood cells, monocytes and macrophages, neutrophils, and lymphocytes increased. Meanwhile, the contents of CD25, CD4, and Foxp3 in lung tissue all increased, and the protein levels of HMGB1, TLR4, and p65 increased. After treatment with andrographolide, the levels of FEV0.3, FEV0.3/FVC, and PEF increased, proving the increase was positively correlated with the concentration of andrographolide. The levels of IL-8, TNF-α, IL-17, and IL-6 in rat alveolar lavage fluid decreased, and the level of IL-10 sequentially. The total number of white blood cells, the number of monocytes and macrophages, the number of lymphocytes, and the neutral Granulocytes decreased significantly. And the contents of CD25, CD4, and Foxp3 in lung tissue significantly decreased, and the protein levels of HMGB1, TLR4, and p65 significantly decreased. The above results indicate that andrographolide might be a potential COPD treatment approach. Andrographolide improves the lung function of rats with COPD, reduces lung inflammation, regulates Th17/Treg balance, and its mechanism may be related to HMGB1/TLR4/NF-кB signaling.

Two dimensional proteomic analysis of serum shows immunological proteins exclusively expressed in sulfur mustard exposed patients with long term pulmonary complications

BACKGROUND

Despite more than 30 years after utilization of sulfur mustard or bis (2-chloroethyl) sulfide (SM) by Iraqi troops against Iranian military members and civilians, there are a lot of reported delayed complications for the exposed people. Nonetheless, the molecular mechanism of action from this chemical warfare agent is not recognized yet.

MATERIAL AND METHOD

In this study, we employed two dimensional gel electrophoresis (2DE) technique to investigate the serum proteins from chemical exposed people compared to non-exposed individuals to provide an inside into molecular mechanism of this chemical agent. Each group was divided into two subgroups including individuals with, and without respiratory complications. For each group, 10 individuals were included after informed consent.

RESULT

The results showed protein spots, which were exclusively/mainly expressed in chemical exposed patients with complications, including T cell receptor alpha, and hematopoietic cell signal transducer. Also there were protein spots that were expressed only in all exposed groups (with and without complications). On the other hand, we could identify protein spots that were exclusively expressed/altered only in non-exposed group with complications including Pre T-cell antigen receptor, CD40 ligand, and multidrug and toxin extrusion proteins.

CONCLUSION

Our investigation could result in identification of proteins that are associated to chemical exposure, as well as those specific for respiratory complications irrespective of chemical exposure. These candidate proteins can be used as biomarker, as well as a base for understanding the molecular mechanism of this chemical agent.

A review of Sulfur Mustard-induced pulmonary immunopathology: An Alveolar Macrophage Approach

Despite many studies investigating the mechanism of Sulfur Mustard (SM) induced lung injury, the underlying mechanism is still unclear. Inflammatory and subsequent fibroproliferative stages of SM-toxicity are based upon several highly-related series of events controlled by the immune system. The inhalation of SM gas variably affects different cell populations within the lungs. Various studies have shown the critical role of macrophages in triggering a pulmonary inflammatory response as well as its maintenance, resolution, and repair. Importantly, macrophages can serve as either pro-inflammatory or anti-inflammatory populations depending on the present conditions at any pathological stage. Different characteristics of macrophages, including their differentiation, phenotypic, and functional properties, as well as interactions with other cell populations determine the outcomes of lung diseases and the extent of long- or short-term pulmonary damage induced by SM. In this paper, we summarize the current state of knowledge regarding the role of alveolar macrophages and their mediators in the pathogenesis of SM in pulmonary injury. Investigating the specific cells and mechanisms involved in SM-lung injury may be useful in finding new target opportunities for treatment of this injury.

Long-term Respiratory Effects of Mustard Vesicants

Sulfur mustard and related vesicants are cytotoxic alkylating agents that cause severe damage to the respiratory tract. Injury is progressive leading, over time, to asthma, bronchitis, bronchiectasis, airway stenosis, and pulmonary fibrosis. As there are no specific therapeutics available for victims of mustard gas poisoning, current clinical treatments mostly provide only symptomatic relief. In this article, the long-term effects of mustards on the respiratory tract are described in humans and experimental animal models in an effort to define cellular and molecular mechanisms contributing to lung injury and disease pathogenesis. A better understanding of mechanisms underlying pulmonary toxicity induced by mustards may help in identifying potential targets for the development of effective clinical therapeutics aimed at mitigating their adverse effects.

Angiogenesis modulatory factors in subjects with chronic ocular complications of Sulfur Mustard exposure: A case-control study

BACKGROUND

Chronic ocular complications of Sulfur Mustard (SM) exposure leads to severe ocular morbidity during time. The aim of this study was to compare serum levels of Interleukin 17 (IL-17), IL-12, vascular endothelial growth factor (VEGF)-C, VEGF-D and nitric oxide (NO) in SM-exposed patients versus the control group and to measure tear concentration of VEGF-C only in the SM-exposed group.

METHODS

In this prospective case control, 128 SM-exposed patients and 31 healthy control subjects were included. In the case group ocular manifestations were classified to three subgroups of mild (19 cases), moderate (31 cases) and severe (78 cases) forms of disease. Serum levels of IL-17, IL-12, NO, VEGF-C and VEGF-D, in all subjects and tear concentration of VEGF-C in SM-exposed group was evaluated.

RESULTS

All subjects were male and mean ± standard deviation (SD) of age in the case and control groups were 44.9 ± 8.8 and 40.9 ± 10.1 years, respectively. Except for significantly lower serum level of IL-17 (p < 0.001) and NO (p = 0.003), other values were not significantly different. The tear concentration of VEGF-C and serum level of IL-12 were not different between subgroups in the SM-exposed group, yet were significantly lower among those with abnormally dilated and tortuous conjunctival vessels and corneal pannus, respectively (p = 0.01, p = 0.015).

CONCLUSIONS

Exposure to SM significantly reduced serum level of IL-17 and NO in the delayed phase, yet did not influence VEGF-C; VEGF-D or IL-12.

Dendritic cells and Th17/Treg ratio play critical roles in pathogenic process of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common disorder of respiratory system. This study aimed to evaluate changes of mature dendritic cells (DCs) and regulatory T cells (Treg) in lung tissues and peripheral blood of COPD patients. For lung tissue analysis, patients were divided into no-smoking and no-COPD (CS-COPD-), smoking and no-COPD (CS + COPD-) and COPD group. For peripheral blood analysis, patients were divided into CS-COPD-, CS + COPD-, stable COPD (SCOPD) and acute exacerbation of COPD (AECOPD) group. Hematoxylin and eosin (HE) staining was used to evaluate inflammation of lung tissues. Immunohistochemistry assay was employed to examine CD80, CCR6, IL-17 A, FoxP3 in lung tissues. DCs and Treg cells were isolated from lung tissues and peripheral blood. Levels of CD80, FoxP3+ Treg, CCR6 and IL-17 A were detected by using flow cytometry. Results showed that FEV%, FVC% and FEV1/FVC were significantly reduced and Bosken scores were remarkably increased in COPD patients compared to non-COPD patients (p < 0.05). CD80 and FoxP3 levels were lower, and CCR6 and IL-17A levels were higher obviously in COPD compared to non-COPD patients (p < 0.05). COPD patients illustrated reduced mDCs levels and enhanced imDCs levels. COPD patients exhibited remarkably higher Th17 levels compared to no-smoking patients (p < 0.05). COPD patients illustrated obviously lower Treg levels and significantly higher Th17/Treg ratio compared to non-smoking patients (p < 0.05). Th17% (Th17/Treg) negatively and Treg% was positively correlated with FEV1%, FEVC%, FEV1/FEVC (p < 0.05). In conclusion, dendritic cells and Th17/Treg ratio play critical roles for pathogenic process of chronic obstructive pulmonary disease.