T cell immunoglobulin and mucin domain-containing molecule 3 on CD14+ monocytes serves as a novel biological marker for diabetes duration in type 2 diabetes mellitus

Immune cell dysfunction: A critical player in development of diabetes complications

Diabetes mellitus, a global health challenge, influences millions worldwide by leading to severe complications and premature death. A key factor in its pathogenesis is immune cell dysfunction, which aggravates both type 1 and type 2 diabetes. The important role that immune cell dysregulation plays in the emergence of diabetes complications is investigated in this research. It highlights the manner in which diabetes compromises the immune system's adaptive as well as innate responses. Key defects in innate immunity include impaired pathogen recognition, and dysfunctional behavior of macrophages, neutrophils, and natural killer (NK) cells. Additionally, the complement system is dysregulated, and cytokine production is altered, affecting overall immune signaling. The study investigates the dysfunction of several T and B cell subsets, such as CD4+ T cells, CD8+ T cells, regulatory T cells, and B cells, in relation to adaptive immunity. These dysfunctions collectively contribute to chronic inflammation, reduced pathogen clearance, and increased susceptibility to infections, ultimately exacerbating diabetes complications. Developing targeted therapies to reduce diabetes complications and enhance patient outcomes requires an understanding of these mechanisms.

Plasma soluble TIM-3 is increased in normoglycemic South Asian women compared to Nordic women after gestational diabetes mellitus and associated with markers of metaflammation

Background

Women with South Asian ethnicity have a higher risk of developing type 2 diabetes mellitus (T2DM) compared with white women of European descent, especially after gestational diabetes mellitus (GDM). Central obesity and adipose tissue dysfunction have been linked to their higher risk of T2DM, but the mechanisms are not known. We hypothesize that low-grade, persistent immune cell activation is involved in metabolic disturbances following GDM with different influence according to ethnicity.

Methods

We measured plasma levels of T cell exhaustion marker soluble T cell immunoglobin mucin domain 3 (sTIM-3), sCD25, sCD27 and soluble lymphocyte activation gene (sLAG)-3 in 266 women of South Asian (n = 160) and white Nordic (n = 106) ethnic background with a history of GDM.

Results

Baseline plasma concentration of sTIM-3 was higher in South Asian women compared to Nordic women (p < 0.001). This difference was driven by higher sTIM-3 in South Asian women with NGT, compared to their Nordic counterparts (p = 0.005) but there were no significant differences comparing Nordic and South Asian women with altered glucose tolerance (AGT). Soluble TIM-3 correlated positively with waist-height ratio (WHtR) and body mass index across all groups, but whereas sTIM-3 correlated moderately and consistently with markers of metaflammation in South Asians, this pattern was not found in Nordic women. Mediation analysis indicated that 15 % of the difference found in adipose insulin resistance between ethnicities could be mediated by sTIM-3, and that 33 % of the difference in sTIM-3 concentrations could be mediated by WHtR. Moreover, T cell markers sCD27 and sLAG3 were also increased in South Asian women compared with Nordic women, further supporting involvement of T cell activation in these women.

Conclusion

We found increased levels of sTIM-3, as well as additional markers of T cell activation/exhaustion, in a population of normoglycemic South Asian women with previous gestational diabetes as compared to women of Nordic descent. The possible causal relationship between T cell activation and metabolic dysfunction in high-risk South Asian women is however still elusive and merits further investigation.

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.

T cell immunoglobulin and mucin domain-containing protein 3 is highly expressed in patients with acute decompensated heart failure and predicts mid-term prognosis

Background and aims

T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) is mainly expressed by immune cells and plays an immunomodulatory role in cardiovascular disease. However, the prognostic value of Tim-3 in acute decompensated heart failure (ADHF) is unclear. This study aimed to investigate the expression profile of Tim-3 on CD4⁺ and CD8⁺ T cells in patients with ADHF and its impact on their prognosis.

Methods

In this prospective study, 84 patients who were hospitalized with ADHF and 83 patients without heart failure were enrolled. Main clinical data were collected during patient visits. The Tim-3 expression on CD4⁺ and CD8⁺ T cells in peripheral blood samples was assayed by flow cytometry. Long-term prognosis of the patients with ADHF was evaluated by major adverse cardiac and cerebrovascular events (MACCE) over a 12-month follow-up period.

Results

We found that the Tim-3 expression on CD4⁺ T cells [2.08% (1.15–2.67%) vs. 0.88% (0.56–1.39%), p < 0.001] and CD8⁺ T cells [3.81% (2.24–6.03%) vs. 1.36% (0.76–3.00%), p < 0.001] in ADHF group were significantly increased vs. the non-ADHF group. Logistic analysis revealed that high levels of Tim-3 expressed on CD4⁺ and CD8⁺ T cells were independent risk factors of ADHF (OR: 2.76; 95% CI: 1.34–5.65, p = 0.006; OR: 2.58; 95% CI: 1.26–5.31, p = 0.010, respectively). ROC curve analysis showed that the high level of Tim-3 on CD4⁺ or CD8⁺ T cells as a biomarker has predictive performance for ADHF (AUC: 0.75; 95% CI: 0.68–0.83; AUC: 0.78, 95% CI: 0.71–0.85, respectively). During a median follow-up of 12 months, the Cox regression analysis revealed that higher Tim-3 on CD4⁺ and CD8⁺ T cells were strongly associated with increased risks of MACCE within 12 months after ADHF (HR: 2.613; 95% CI: 1.11–6.13, p = 0.027; HR: 2.762, 95% CI: 1.15–6.63, p = 0.023; respectively).

Conclusion

Our research indicated that the expression level of Tim-3 on CD4⁺ and CD8⁺ T cells, elevated in patients with ADHF, was an independent predictor of MACCE within 12 months after ADHF. It suggests a potential immunoregulatory role of Tim-3 signaling system in the mechanism of ADHF.

Tim-3 Expression Causes NK Cell Dysfunction in Type 2 Diabetes Patients

Type 2 diabetes mellitus (T2DM) is characterized by high blood glucose levels and chronic low-grade inflammation. It shows a strong association with obesity and immune dysfunction, which makes T2DM patients more susceptible to infectious diseases. NK cells play an important role in pathogen control and tumor surveillance. However, whether NK cell distribution and functional status are altered in T2DM is unclear. To address this issue, we compared surface receptor expression and cytokine production between peripheral blood NK cells from 90 T2DM patients and 62 age- and sex-matched healthy controls. We found a significantly lower frequency and absolute number of NK cells in patients than in controls. Interestingly, the expression of inhibitory receptor Tim-3 was significantly increased, while the expression of the activating receptor NKG2D was significantly decreased, in T2DM NK cells. Both TNF-α secretion and degranulation capacity (evidenced by CD107a expression) were dampened in NK cells from patients. The expression of Tim-3 on NK cells correlated positively with both HbA1c and fasting blood glucose levels and negatively with the percentage and absolute number of total NK cells and was associated with increased NK cell apoptosis. In addition, Tim-3 expression on NK cells negatively correlated with TNF-α production, which could be restored by blocking Galectin-9/Tim-3 pathway. Our results suggest that NK cell dysfunction secondary to augmented Tim-3 expression occurs in T2DM patients, which may partly explain their increased susceptibility to cancer and infectious disease.

Increased Tim-3+ monocytes/macrophages are associated with disease severity in patients with IgA nephropathy

T-cell immunoglobulin and mucin-domain-containing protein-3 (Tim-3) plays multiple important roles in immune response and participates in the pathogenesis of various inflammatory diseases by regulating macrophage polarization. However, its functions in the development of IgA nephropathy (IgAN) are still unclear. In this study, changes in the relative levels of Tim-3⁺ monocytes/macrophages in peripheral blood and renal tissue, and their clinical significance in patients with IgAN were investigated. The expression of CD68 and Tim-3 in macrophages from patients with IgAN was determined via immunohistochemistry and immunofluorescence staining assays. Peripheral blood of 48 patients with biopsy-proven IgAN and 18 healthy controls (HCs) was collected to determine the frequency of circulating CD14⁺Tim-3⁺ cells using flow cytometry, before and after 24 weeks of prednisolone treatment. Serum interleukin (IL)-10 and tumor necrosis factor α (TNF-α) levels were measured using enzyme-linked immunosorbent assays. The potential association between clinical signs and Tim-3⁺ monocytes/macrophages was analyzed. The percentages of circulating CD14⁺Tim-3⁺ monocytes were higher in samples from patients with IgAN than in those from HCs and were positively associated with the pathological features (segmental glomerulosclerosis and tubular atrophy/interstitial fibrosis) of IgAN, according to the Oxford classification. Tissue staining assays revealed cells positive for both CD68 and Tim-3 in tubulointerstitial lesions of IgAN patients. In addition, elevated levels of serum IL-10 and TNF-α were detected in these patients in comparison to HCs. Furthermore, the frequency of circulating CD14⁺Tim-3⁺ monocytes had a positive correlation with levels of 24-h urinary protein and serum IL-10, and was negatively associated with renal function. After 24 weeks of treatment with prednisolone, the percentages of CD14⁺Tim-3⁺ cells were significantly reduced. In summary, our findings indicate that Tim-3⁺ monocytes/macrophages might be involved in the pathogenesisof IgAN and could be used as a potential indicator to evaluate disease severity.

Alajez N, Abu Nada M, Elkord E. Transcriptomic Profiling of Tumor-Infiltrating CD4+TIM-3+ T Cells Reveals Their Suppressive, Exhausted, and Metastatic Characteristics in Colorectal Cancer Patients

T cell immunoglobulin mucin-3 (TIM-3) is an immune checkpoint identified as one of the key players in regulating T-cell responses. Studies have shown that TIM-3 is upregulated in the tumor microenvironment (TME). However, the precise role of TIM-3 in colorectal cancer (CRC) TME is yet to be elucidated. We performed phenotypic and molecular characterization of TIM-3⁺ T cells in the TME and circulation of CRC patients by analyzing tumor tissues (TT, TILs), normal tissues (NT, NILs), and peripheral blood mononuclear cells (PBMC). TIM-3 was upregulated on both CD4⁺ and CD3⁺CD4⁻ (CD8⁺) TILs. CD4⁺TIM-3⁺ TILs expressed higher levels of T regulatory cell (Tregs)-signature genes, including FoxP3 and Helios, compared with their TIM-3⁻ counterparts. Transcriptomic and ingenuity pathway analyses showed that TIM-3 potentially activates inflammatory and tumor metastatic pathways. Moreover, NF-κB-mediated transcription factors were upregulated in CD4⁺TIM-3⁺ TILs, which could favor proliferation/invasion and induce inflammatory and T-cell exhaustion pathways. In addition, we found that CD4⁺TIM-3⁺ TILs potentially support tumor invasion and metastasis, compared with conventional CD4⁺CD25⁺ Tregs in the CRC TME. However, functional studies are warranted to support these findings. In conclusion, this study discloses some of the functional pathways of TIM-3⁺ TILs, which could improve their targeting in more specific therapeutic approaches in CRC patients.

The frequency of Tim-3 on circulating Tfh cells was increased in type 2 diabetes mellitus patients

Type 2 diabetes mellitus (T2DM) is a chronic, low-grade inflammation disease. T follicular helper (Tfh) cells and T cell immunoglobulin and mucin domain 3 (Tim-3) are implicated in many immune diseases. This study aims to explore whether Tim-3 expression on Tfh cells is associated with T2DM progression. White blood cells (WBCs) were harvested from 30 patients with T2DM and 20 healthy donors. The abundance of circulating Tfh cells (cTfh) and the frequency of Tim-3 were analyzed by flow cytometry. Levels of fasting plasma glucose (FPG), insulin, hemoglobin A1C (HbA1C), and fasting plasma C-peptide were measured. Body mass index (BMI) and diabetes duration were also recorded. Patients with T2DM had higher numbers of cTfh cells. In addition, cTfh cells showed a negative correlation with HbA1C and diabetes duration, a positive correlation with fasting plasma C-peptide. The frequency of Tim-3 on cTfh cells was higher among T2DM patients compared with healthy donors. The in vitro experiment showed that high glucose levels increased the abundance cTfh cells but had no effect on Tim-3 expression. Our results suggest that cTfh cells and associated Tim-3 frequency may contribute to the progression of T2DM, and high glucose levels may influence cTfh cells directly.

Circulating T Cells Exhibit Different TIM3/Galectin-9 Expression in Patients with Obesity and Obesity-Related Diabetes

AIMS

Obesity is highly associated with type 2 diabetes mellitus (T2DM). The TIM3/galectin-9 pathway plays an important role in immune tolerance. Herein, we aimed to investigate the expression of TIM3 and galectin-9 in peripheral blood and to evaluate their clinical significance in patients with obesity and obesity-related T2DM.

METHODS

We performed flow cytometry on peripheral blood samples from healthy donors (HC), patients with simple obesity (OB), and patients with obesity comorbid T2DM (OD). The expression of TIM3 on CD3⁺, CD4⁺, and CD8⁺ T cells was determined. The level of galectin-9 in plasma was detected by ELISA.

RESULTS

We demonstrated the enhancement of TIM3 on CD3⁺, CD4⁺, and CD8⁺ T cells in the OB group when compared with healthy controls, while it was decreased significantly in the OD group. The TIM3⁺CD8⁺ T cells of the OB group were positively correlated with risk factors including BMI, body fat rate, and hipline. The concentration of galectin-9 of the OD group in plasma was significantly higher than that of healthy donors and the OB group. Moreover, the level of galectin-9 of the OD group was positively correlated with fasting insulin and C-peptide, which were two clinical features that represented pancreatic islet function in T2DM.

CONCLUSIONS

Our results suggested that TIM3 and galectin-9 may be potential biomarkers related to the pathogenesis of obesity-related T2DM.

Level of serum soluble Tim-3 expression in early-phase acute pancreatitis

BACKGROUND/AIMS

T-cell immunoglobulin and mucin domain 3 (Tim-3) assumedly play a crucial immunomodulatory role in inflammatory response. Data on the potential role of soluble Tim-3 (sTim-3) in acute pancreatitis (AP) are scarce. We conducted a prospective clinical study to characterize its role in the early-phase AP.

METHODS

In total, 44 patients with AP (16 mild and 28 none-mild) who presented within 24 hours on admission and 20 healthy volunteers (NC) were included in our study. Serum interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, and sTim-3 levels were detected using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Levels of the pro-inflammatory cytokines IL-6 and TNF-α and the anti-inflammatory cytokine IL-10 in the none-mild and mild groups were significantly elevated compared with those of the NC group. The sTim-3 levels of the none-mild and mild group were significantly increased compared with the NC. The sTim-3 level positively correlated with the IL-6 and TNF-α but showed no obvious correlations with the IL-10 level. The sTim-3 level positively correlated with the APACHE II score.

CONCLUSION

The results indicate that sTim-3 participates in the early progression of AP by positively regulating the pro-inflammatory cytokines and that the measurement of serum sTim-3 is an early marker for predicting AP.

Unlike PD-L1, PD-1 Is Downregulated on Partial Immune Cells in Type 2 Diabetes

INTRODUCTION

Type 2 diabetes is a worldwide disease which is associated with chronic, low-grade inflammation. The PD-1/PD-L1 pathway has been reported to be a negative regulatory element in immune homeostasis and to be involved in many diseases.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from type 2 diabetes patients (n = 23) and healthy donors (n = 20). The PD-L1 and PD-1 expressions on corresponding immune cells were evaluated by flow cytometry.

RESULTS

The PD-L1 expression on corresponding immune cells has no significant difference between these two groups. We showed the downregulated PD-1 expression in type 2 diabetes patients. The correlation analysis indicated that the PD-1 on NK cells has a positive correlation with insulin and diabetes duration. And an inverse correlation has been shown between the PD-1 expression on monocytes and BMI (body mass index).

CONCLUSIONS

The results in this article suggest that PD-1, unlike PD-L1, might participate in the progression of type 2 diabetes. This investigation will provide evidence for the potential immune therapy for T2D.

miR-330-5p/Tim-3 axis regulates macrophage M2 polarization and insulin resistance in diabetes mice

Obesity is associated with a state of low-grade inflammatory response in adipose tissue, and contributes to the development of type 2 diabetes. Immune cells such as macrophages can infiltrate adipose tissue and are responsible for the majority of inflammatory cytokine production. Therefore, adipose tissue promotes macrophage infiltration, resulting in local inflammation and insulin resistance. Tim-3 negatively regulates IFN-γ secretion and influences the ability to induce T cell tolerance in diabetes. MicroRNA contributes to the development of immunological tolerance and involves in macrophage polarization. However, the potential of Tim-3 to regulate macrophage polarization and the related microRNA has not been reported. In this experiment, 8-week-old C57BL/6 mice were fed a high-fat diet for 8 weeks. The adipose tissue macrophages were isolated, miR-330-5p and Tim-3 levels, and M1/M2 polarization were analyzed. In addition, insulin tolerance tests was detected. The results demonstrated that miR-330-5p levels increased but Tim-3 levels decreased, leading to M1 polarization and insulin tolerance in diabetes mice. In addition, inhibition of miR-330-5p enhanced Tim-3 levels, leading to M2 polarization and insulin tolerance attenuation in diabetes mice. Furthermore, we detected the inverse relationship between miR-330-5p and Tim-3. We found that Tim-3 mRNA contained conserved miR-330-5p binding sites in its 3'UTR, and miR-330-5p could directly regulate Tim-3 expression through these 3'UTR sites. Our study demonstrated that miR-330-5p served as a regulator of the M2 polarization and miR-330-5p/Tim-3 axis potentially down-regulated insulin resistance in diabetes, probably through enhancing the M2 polarization of macrophage.

Tim-3在肝脏疾病中的调节作用

T淋巴细胞免疫球蛋白黏蛋白分子(T-cell immunoglobulin domain and mucin domain-containing molecule, Tim)-3是Tim家族中的一员, 为近年来新发现的一种在辅助Ⅰ型T淋巴细胞(Help T cell 1, Th1)上特异性表达的Ⅰ型细胞表面分子. Tim-3作为负性调节因子通过与其配体Galectin-9结合引起细胞死亡, 进而调控Th1型细胞功能. Tim-3还表达于其他类型细胞表面, 如自然杀伤细胞、树突状细胞和单核细胞, 对自身免疫性疾病和其他免疫介导的疾病进行免疫调控. 对Tim-3在不同细胞不同免疫条件下的功能以及如何调节进行研究, 将有利于研发Tim-3的潜在治疗作用. 近年来大量研究显示Tim-3通道与肝脏疾病发生发展有着密切关系, 本文就其在肝脏疾病中的调节作用做一总结.

T cell immunoglobulin and mucin domain-containing molecule 3 on CD14+ monocytes serves as a novel biological marker for diabetes duration in type 2 diabetes mellitus

Aims/Introduction

Type 2 diabetes is a worldwide disease that is associated with increased rates of obesity and reduced physical activity. Obesity‐associated insulin resistance in type 2 diabetes is a disorder in the balance between pro‐inflammatory and anti‐inflammatory signals. T cell immunoglobulin and mucin domain‐containing molecule 3 (Tim‐3) has been reported as an important regulatory inflammation molecule, and plays a pivotal role in several inflammation‐related diseases.

Materials and Methods

Peripheral blood mononuclear cells were obtained from type 2 diabetes patients (n = 31) and healthy donors (n = 18), and Tim‐3 expression on peripheral blood mononuclear cells was evaluated by flow cytometry.

Results

We showed the downregulated expression of Tim‐3 on CD14⁺ monocytes from type 2 diabetes patients. In addition, the upregulated expression of Tim‐3 on peripheral CD4⁺ T cells and CD8⁺ T cells was observed in the present study. The correlation analysis between Tim‐3 expression on CD14⁺ monocytes and diabetes duration showed the longer diabetes duration time, the lower Tim‐3 expression on CD14 monocytes.

Conclusions

The present results suggest that Tim‐3 might participate in the progression of type 2 diabetes by its negative regulation on these immune cells, and Tim‐3 on CD14⁺ monocytes serves as a novel biological marker for diabetes duration in type 2 diabetes patients.