Changes of Th17 cells, regulatory T cells, Treg/Th17, IL-17 and IL-10 in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

Implication of serum soluble IL-2 receptor α in type 2 diabetes mellitus

Objectives

The aim of this study was to determine the association of serum soluble IL-2 receptor α (sIL-2RA) with T2DM-related characteristics and complications.

Methods

Serum sIL-2RA levels were determined in 156 T2DM patients, and the association with T2DM-related characteristics and complications was evaluated.

Results

Serum sIL-2RA levels were significantly increased in T2DM patients with diabetic kidney disease (DKD) (median, IQR, 1434.9, 958.1-1896.0, pg/ml), in comparison with those without DKD (median, IQR, 851.2, 660.2-1089.9, pg/ml)(P < 0.001). The ROC analysis revealed good performance of sIL-2RA for identifying DKD, with the areas under the curve of 0.789 (95%CI of 0.711-0.867, P < 0.001). The correlation analyses showed significantly positive correlations of serum sIL-2RA with urea (r = 0.458, P < 0.001), creatinine (r = 0.508, P < 0.001) and uACR (r = 0.469, P < 0.001), and negative correlation with eGFR (r=-0.561, P < 0.001). The multivariate analyses showed that serum sIL-2RA was independently associated with the increased risks of DKD (OR, 95%CI, 6.539, 1.401-30.529, P = 0.017) and DR (OR, 95%CI, 3.606, 1.073-12.114, P = 0.038). Additionally, serum sIL-2RA was significantly associated with inflammatory indicators in DKD patients, and with metablic indicators in non-DKD patients (all P < 0.05).

Conclusion

Serum sIL-2RA may be closely associated with inflammation, glucose and lipid metabolisms, DKD and DR risks in T2DM. Furthermore, it may be a potential biomarker for T2DM-related micro-vascular complications.

Role of Peripheral Blood Regulatory T Cells and IL-2 in the Collateral Circulation of Acute Ischemic Stroke

Background

Inflammation is recognized as a pivotal factor in the pathophysiology of acute ischemic stroke (AIS) and has the potential to influence the collateral circulation of patients. The objective of this investigation was to explore the link between peripheral regulatory T cells (Tregs), interleukin-2 (IL-2), and the status of collateral circulation.

Methods

Between September 2023 and May 2024, the study incorporated 117 AIS patients from the neurology department, with 60 identified as having good collateral status (GCS) and 57 with poor collateral status (PCS). Additionally, a control group of 46 healthy individuals was included. Collateral circulation in AIS patients was assessed via computed tomography angiography. The levels of peripheral blood Tregs were quantified through flow cytometry, while IL-2 was measured by ELISA.

Results

In this investigation, patients diagnosed with PCS demonstrated reduced Tregs (5.77 ± 1.55%) and IL-2 levels (7.37 ± 2.61 pg/mL) compared to individuals with GCS (7.09 ± 1.32%, 9.95 ± 3.58 pg/mL) and healthy controls (7.17 ± 1.40%,10.33 ± 4.01 pg/mL). Logistic regression analysis identified significant associations between Tregs and IL-2 levels and collateral circulation status (p<0.05), with diminished levels of both being independent predictors of PCS when compared to GCS. A nomogram was developed to forecast risk factors for collateral circulation, further highlighting the potential of plasma Tregs and IL-2 levels as biomarkers in predicting collateral circulation among AIS patients. The diagnostic performance of Tregs and IL-2 was assessed utilizing receiver operating characteristic (ROC) analysis. The area under the ROC curve (AUC) for Tregs in differentiating GCS from PCS patients was ascertained to be 0.741 (95% confidence interval [CI]: 0.652-0.830), while for IL-2, it was 0.710 (95% CI: 0.618-0.803). Moreover, the combined measurement of Tregs and IL-2 resulted in an AUC of 0.779 (95% CI: 0.695-0.863).

Conclusion

Plasma levels of peripheral blood Tregs and IL-2 may function as promising biomarkers for the prediction of collateral circulation status, suggesting potential new therapeutic approaches aimed at enhancing cerebral collateral circulation, and providing new therapeutic targets for acute ischemic stroke.

Improving regulatory T cell-based therapy: insights into post-translational modification regulation

Regulatory T (Treg) cells are pivotal for maintaining immune homeostasis and play essential roles in various diseases, such as autoimmune diseases, graft-versus-host disease (GVHD), tumors, and infectious diseases. Treg cells exert suppressive function via distinct mechanisms, including inhibitory cytokines, granzyme or perforin-mediated cytolysis, metabolic disruption, and suppression of dendritic cells. Forkhead Box P3 (FOXP3), the characteristic transcription factor, is essential for Treg cell function and plasticity. Cumulative evidence has demonstrated that FOXP3 activity and Treg cell function are modulated by a variety of post-translational modifications (PTMs), including ubiquitination, acetylation, phosphorylation, methylation, glycosylation, poly(ADP-ribosyl)ation, and uncharacterized modifications. This review describes Treg cell suppressive mechanisms and summarizes the current evidence on PTM regulation of FOXP3 and Treg cell function. Understanding the regulatory role of PTMs in Treg cell plasticity and function will be helpful in designing therapeutic strategies for autoimmune diseases, GVHD, tumors, and infectious diseases.

Schistosoma antigens: A future clinical magic bullet for autoimmune diseases?

Autoimmune diseases are characterized by dysregulated immunity against self-antigens. Current treatment of autoimmune diseases largely relies on suppressing host immunity to prevent excessive inflammation. Other immunotherapy options, such as cytokine or cell-targeted therapies, have also been used. However, most patients do not benefit from these therapies as recurrence of the disease usually occurs. Therefore, more effort is needed to find alternative immune therapeutics. Schistosoma infection has been a significant public health problem in most developing countries. Schistosoma parasites produce eggs that continuously secrete soluble egg antigen (SEA), which is a known modulator of host immune responses by enhancing Th2 immunity and alleviating outcomes of Th1 and Th17 responses. Recently, SEA has shown promise in treating autoimmune disorders due to their substantial immune-regulatory effects. Despite this interest, how these antigens modulate human immunity demonstrates only limited pieces of evidence, and whether there is potential for Schistosoma antigens in other diseases in the future remains an unsolved question. This review discusses how SEA modulates human immune responses and its potential for development as a novel immunotherapeutic for autoimmune diseases. We also discuss the immune modulatory effects of other non-SEA schistosome antigens at different stages of the parasite's life cycle.

Associations of Placental Inflammation and Oxidative Stress Biomarkers with Glucolipid Metabolism in Children: A Birth Cohort Study in China

BACKGROUND

The maternal intrauterine immune environment may affect offspring long-term health. We aimed to investigate the association between the intrauterine placental immunological milieu and glycolipid metabolic health in children.

METHODS AND RESULTS

This study enrolled 1803 mother-child pairs from the Ma'anshan birth cohort (2013-2014). Placental mRNA expression of inflammatory cytokines (interleukin-1β [IL-1β], IL-10, monocyte chemoattractant protein-1, tumor necrosis factor-α, IL-4, IL-6, IL-8, C-reactive protein, and interferon-γ) and oxidative stress biomarkers (heme oxygenase-1, hypoxia-inducible factor-1alpha, and glucose-related protein 78) was quantified using real-time quantitative polymerase chain reaction. Fasting blood glucose, insulin, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol were assessed at 5 to 6 years old. Statistical analyses included multiple linear regression, binary logistic regression, restricted cubic spline model, and the Bayesian kernel machine regression model. Placental inflammatory cytokines (IL-1β, monocyte chemoattractant protein-1, C-reactive protein, IL-6, IL-8, IL-10) and oxidative stress biomarkers (heme oxygenase-1, hypoxia-inducible factor-1alpha, glucose-related protein 78) showed positive associations with children's fasting blood glucose levels. Heme oxygenase-1 and glucose-related protein 78 exhibited negative correlations with children's fasting insulin levels. Elevated IL-6, heme oxygenase-1, hypoxia-inducible factor-1alpha, and glucose-related protein 78 were associated with increased risk of prediabetes in children. Overall upregulation of placental proinflammatory cytokines and oxidative stress factors mRNA expression correlated with higher prediabetes risk in children. Bayesian kernel machine regression analysis indicated a joint positive effect of the 12 placental inflammation and oxidative stress mixtures on children's risk of high fasting blood glucose.

CONCLUSIONS

This exploratory study underscores significant correlations between maternal intrauterine placental inflammation, oxidative stress markers, and offspring fasting blood glucose and insulin levels. These findings highlight the potential role of intrauterine holistic immunity in shaping offspring glucose metabolism health.

Quantitative analysis of Tr1 lymphocytes in patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is usually accompanied by a low-grade inflammatory phenomenon, which participates in the pathogenesis of different complications of this condition. The inflammatory response is under the regulation of different mechanisms, including T regulatory (Treg) lymphocytes. However, the possible role of type 1 T regulatory (Tr1) cells in T2DM has not been explored so far.

AIM

To carry out a quantitative analysis of Tr1 lymphocytes and other immune cell subsets in patients with T2DM and correlate these results with clinical findings and treatments.

MATERIALS AND METHODS

Sixty patients with T2DM and twenty-three healthy controls were included in the study. Biochemical and anthropometric variables were evaluated, and Tr1 lymphocytes (CD4+CD49+LAG-3+IL-10+) and other cell subsets (Th17, Th22 and Foxp3 + Treg cells) were analyzed in peripheral blood samples by multiparametric flow cytometry.

RESULTS

Significant increased levels of Tr1 cells were detected in patients with severe and mild disease, compared to healthy controls. In addition, CD4+IL-10+ lymphocytes were also increased in patients with T2DM. In contrast, similar levels of Foxp3+ Treg cells, Th17 and Th22 lymphocytes were observed in patients and controls. Likewise, no significant associations were detected between Tr1 cell levels and different clinical and laboratory parameters. However, those patients receiving glucagon-like peptide-1 receptor agonists (GLP-1-RA) showed similar levels of Tr1 cells than healthy controls, and significant lower numbers than untreated patients.

CONCLUSION

We observed an increase in Tr1 and CD4+IL10+ lymphocyte levels in T2DM. Moreover, GLP1-RA treatment was significantly associated with normalization of the Tr1 levels. This highlights another potential immune dysfunction in patients with T2DM, which could participate in the pathogenesis of this condition.

Inflammatory and endothelial host responses in community-acquired pneumonia: exploring the relationships with HbA1c, admission plasma glucose, and glycaemic gap-a cross-sectional study

Introduction

Diabetes is associated with dysregulated immune function and impaired cytokine release, while transient acute hyperglycaemia has been shown to enhance inflammatory cytokine release in preclinical studies. Although diabetes and acute hyperglycaemia are common among patients with community-acquired pneumonia (CAP), the impact of chronic, acute, and acute-on-chronic hyperglycaemia on the host response within this population remains poorly understood. This study investigated whether chronic, acute, and acute-on- chronic hyperglycaemia are associated with distinct mediators of inflammatory, endothelial, and angiogenic host response pathways in patients with CAP.

Methods

In a cross-sectional study of 555 patients with CAP, HbA1c, admission plasma (p)-glucose, and the glycaemic gap (admission p-glucose minus HbA1c- derived average p-glucose) were employed as measures of chronic, acute, and acute-on-chronic hyperglycaemia, respectively. Linear regression was used to model the associations between the hyperglycaemia measures and 47 proteins involved in inflammation, endothelial activation, and angiogenesis measured at admission. The models were adjusted for age, sex, CAP severity, pathogen, immunosuppression, comorbidity, and body mass index. Adjustments for multiple testing were performed with a false discovery rate threshold of less than 0.05.

Results

The analyses showed that HbA1c levels were positively associated with IL-8, IL-15, IL-17A/F, IL-1RA, sFlt-1, and VEGF-C. Admission plasma glucose was also positively associated with these proteins and GM-CSF. The glycaemic gap was positively associated with IL-8, IL-15, IL-17A/F, IL-2, and VEGF-C.

Conclusion

In conclusion, chronic, acute, and acute-on-chronic hyperglycaemia were positively associated with similar host response mediators. Furthermore, acute and acute-on-chronic hyperglycaemia had unique associations with the inflammatory pathways involving GM-CSF and IL-2, respectively.

Research Progress on the Weak Immune Response to the COVID-19 Vaccine in Patients with Type 2 Diabetes

Coronavirus Disease 2019 (COVID-19) is generally susceptible to the population, highly infectious, rapidly transmitted, and highly fatal. There is a lack of specific drugs against the virus at present and vaccination is the most effective strategy to prevent infection. However, studies have found that some groups, particularly patients with diabetes, show varying degrees of weak immune reactivity to various COVID-19 vaccines, resulting in poor preventive efficacy against the novel coronavirus in patients with diabetes. Therefore, in this study, patients with type 2 diabetes mellitus (T2DM) who had weak immune response to the COVID-19 vaccine in recent years were analyzed. This article reviews the phenomenon, preliminary mechanism, and related factors affecting weak vaccine response in patients with T2DM, which is expected to help in the development of new vaccines for high-risk groups for COVID-19.

The dynamic shifts of IL-10-producing Th17 and IL-17-producing Treg in health and disease: a crosstalk between ancient "Yin-Yang" theory and modern immunology

The changes in T regulatory cell (Treg) and T helper cell (Th) 17 ratios holds paramount importance in ensuring internal homeostasis and disease progression. Recently, novel subsets of Treg and Th17, namely IL-17-producing Treg and IL-10-producing Th17 have been identified. IL-17-producing Treg and IL-10-producing Th17 are widely considered as the intermediates during Treg/Th17 transformation. These "bi-functional" cells exhibit plasticity and have been demonstrated with important roles in multiple physiological functions and disease processes. Yin and Yang represent opposing aspects of phenomena according to the ancient Chinese philosophy "Yin-Yang" theory. Furthermore, Yin can transform into Yang, and vice versa, under specific conditions. This theory has been widely used to describe the contrasting functions of immune cells and molecules. Therefore, immune-activating populations (Th17, M1 macrophage, etc.) and immune overreaction (inflammation, autoimmunity) can be considered Yang, while immunosuppressive populations (Treg, M2 macrophage, etc.) and immunosuppression (tumor, immunodeficiency) can be considered Yin. However, another important connotation of "Yin-Yang" theory, the conversion between Yin and Yang, has been rarely documented in immune studies. The discovery of IL-17-producing Treg and IL-10-producing Th17 enriches the meaning of "Yin-Yang" theory and further promotes the relationship between ancient "Yin-Yang" theory and modern immunology. Besides, illustrating the functions of IL-17-producing Treg and IL-10-producing Th17 and mechanisms governing their differentiation provides valuable insights into the mechanisms underlying the dynamically changing statement of immune statement in health and diseases.

Periodontal Disease, Local and Systemic Inflammation in Puerto Ricans with Type 2 Diabetes Mellitus

Periodontal disease (PD) is prevalent in type 2 diabetic condition (T2DM).

OBJECTIVES

We assessed the associations between serum or gingival crevicular fluid (GCF) endothelial and inflammatory mediators and chronic PD among T2DM Hispanic adults.

METHODS

We enrolled 248 Puerto Rican residents with T2DM aged 40-65 years. The exposures included serum inflammatory mediators (IL-1b, IL-6, IL-10, and TNF-α), endothelial adhesion molecules, RANKL levels, and the GCF content of these analytes from a subset of 158 samples. The outcomes included the percent of sites with a probing pocket depth (PPD) ≥ 4 mm and clinical attachment loss ≥ 4 mm. Adjusted logistic regression models were fit to the categorized outcomes.

RESULTS

Increased serum IL-10 (Adj. OR: 1.10, p = 0.04), sICAM-1 (Adj. OR: 1.01; p = 0.06), and elevated serum IL-1β (Adj. OR: 1.93; p = 0.06) were statistically significant or close to being significantly associated with a percent of sites with PPD ≥ 4 mm. An increase in GCF IL-1α (Adj. OR: 1.16; p < 0.01) and IL-1β (Adj: 2.40; p = 0.02) was associated with periodontal parameters.

CONCLUSIONS

Our findings suggested that oral and systemic endothelial and inflammatory mediators are associated with periodontal clinical parameters among Hispanic adults with T2DM.

Immunoregulation via Cell Density and Quorum Sensing-like Mechanisms: An Underexplored Emerging Field with Potential Translational Implications

Quorum sensing (QS) was historically described as a mechanism by which bacteria detect and optimize their population density via gene regulation based on dynamic environmental cues. Recently, it was proposed that QS or similar mechanisms may have broader applications across different species and cell types. Indeed, emerging evidence shows that the mammalian immune system can also elicit coordinated responses on a population level to regulate cell density and function, thus suggesting that QS-like mechanisms may also be a beneficial trait of the immune system. In this review, we explore and discuss potential QS-like mechanisms deployed by the immune system to coordinate cellular-level responses, such as T cell responses mediated via the common gamma chain (γc) receptor cytokines and the aryl hydrocarbon receptors (AhRs). We present evidence regarding a novel role of QS as a multifunctional mechanism coordinating CD4⁺ and CD8⁺ T cell behavior during steady state and in response to infection, inflammatory diseases, and cancer. Successful clinical therapies such as adoptive cell transfer for cancer treatment may be re-evaluated to harness the effects of the QS mechanism(s) and enhance treatment responsiveness. Moreover, we discuss how signaling threshold perturbations through QS-like mediators may result in disturbances of the complex crosstalk between immune cell populations, undesired T cell responses, and induction of autoimmune pathology. Finally, we discuss the potential therapeutic role of modulating immune-system-related QS as a promising avenue to treat human diseases.