Effects of T cell leptin signaling on systemic glucose tolerance and T cell responses in obesity

Nutritional conditions and PFS and OS in cancer immunotherapy: the MOUSEION-010 meta-analysis

BACKGROUND

The MOUSEION-010 Meta-Analysis assessed the association between nutritional status and clinical outcomes such as Progression Free Survival (PFS) and Overall Survival (OS) among cancer patients treated with immune checkpoint inhibitors (ICIs).

METHODS

Nutritional status was assessed based on the Prognostic Nutrition Index (PNI), Geriatric Nutritional Risk Index (GNRI) and Controlling Nutritional Status (CONUT) indexes. Databases consulted were: Embase, PubMed, Scopus and Web of Science.

RESULTS

PNI and GNRI indexes did not show a significant association with both PFS and OS, while CONUT index displayed a significant difference in PFS between the two groups, in favor of the control group (Z = 4.04; p < 0.01) also without any publication bias (β= -1.27; 95% CI = [-2.13; -0.42]; p = 0.10]). The same trend was recorded in OS, too (Z = 4.24; p < 0.01). However, publication bias was present (β = 1.89; 95% CI = [1.26; 2.54]; p = 0.028]) and the numerosity of the studies did not reveal the sufficient statistical power to obtain reliable results.

CONCLUSION

Malnutrition could negatively impact cancer patients, especially in advanced phases. Our findings could be associated with the reduction of physical ability and daily activity performance, lower compliance with treatment protocols, and shorter survival outcomes.

The Impact of Gastric Leptin and Leptin Receptor Expression on Metabolic Outcomes Post Laparoscopic Sleeve Gastrectomy

PURPOSE

Obesity is a growing global crisis, with predictions that nearly half of the world's population will be overweight or with severe obesity by 2030. Metabolic bariatric surgery, effective for those unable to lose weight through conventional methods, results in significant weight loss and alleviates associated medical problems. This study investigates changes in gastric leptin (LE) and leptin receptor (LER) expression following laparoscopic sleeve gastrectomy (LSG) and explores their metabolic contributions to surgical outcomes.

MATERIALS AND METHODS

Immunohistochemical staining for LE and LER was performed on gastric tissue biopsies from 54 patients pre- and post-LSG. Expression levels were scored for each epithelium and connective tissue component. Changes in these scores post-LSG were analyzed and correlated with body mass index (BMI), total weight loss (TWL), blood hemoglobin A1c, blood cholesterol, and triglyceride levels. Statistical analysis included paired t-tests, Pearson correlation coefficients, and one-way ANOVA.

RESULTS

Significant decreases in LE and LER receptor expression were observed post-LSG, correlating with reductions in BMI, blood hemoglobin A1c, total cholesterol, and triglyceride levels. The mean BMI decreased from 46.82 kg/m2 pre-surgery to 32.45 kg/m2 at 1 year post-surgery (p < 0.001). Hemoglobin A1c levels reduced from 7.8% to 5.9% (p < 0.001). Total cholesterol and triglyceride levels showed significant reductions, with cholesterol decreasing from 220 mg/dL to 180 mg/dL (p < 0.001) and triglycerides from 180 mg/dL to 120 mg/dL (p < 0.001). Pearson correlation coefficients demonstrated strong negative correlations between LE expression and BMI (r = -0.65, p < 0.001) and between LER expression and hemoglobin A1c (r = -0.60, p < 0.001).

CONCLUSIONS

Beyond weight reduction, the decreased expression of gastric LE and LER post-LSG contributes metabolically to weight loss and improved associated metabolic parameters following the metabolic bariatric surgery.

A detective story of intermittent fasting effect on immunity

Intermittent fasting (IF) refers to periodic fasting routines, that caloric intake is minimized not by meal portion size reduction but by intermittently eliminating ingestion of one or several consecutive meals. IF can instigate comprehensive and multifaceted alterations in energy metabolism, these metabolic channels may aboundingly function as primordial mechanisms that interface with the immune system, instigating intricate immune transformations. This review delivers a comprehensive understanding of IF, paying particular attention to its influence on the immune system, thus seeking to bridge these two research domains. We explore how IF effects lipid metabolism, hormonal levels, circadian rhythm, autophagy, oxidative stress, gut microbiota, and intestinal barrier integrity, and conjecture about the mechanisms orchestrating the intersect between these factors and the immune system. Moreover, the review includes research findings on the implications of IF on the immune system and patients burdened with autoimmune diseases.

Impact of hyperglycemia on immune cell function: a comprehensive review

Hyperglycemia, a hallmark of diabetes and various metabolic disorders, has profound implications for immune cell function. The relationship between elevated blood glucose levels and immune cell function is a topic of significant medical interest. In this review, we aim to comprehensively review effects of hyperglycemia on various immune cell types and its clinical implications, particularly T cells, macrophages, natural killer cells, and neutrophils. It aims to consolidate current knowledge on the subject, with a focus on both type 1 and type 2 diabetes, as well as other pathological states where hyperglycemia is a concern. A comprehensive examination of recent studies and clinical data was conducted to assess effects of hyperglycemia on immune cell function. Evidence indicates that hyperglycemia can significantly alter immune cell function, with different diabetic conditions showing varied responses. Roles of key metabolic hormones in regulating T cell function highlight potential therapeutic targets for restoring immune balance. In addition, reprogramming of innate immune cells such as macrophages and natural killer cells under hyperglycemic conditions suggests a complex metabolic-immunological interface. This review will contribute to a better understanding of the link between diabetes, other metabolic disorders, and immune function. By examining recent research and clinical findings, this review will enhance our comprehension of the mechanisms at play and guide future medical strategies for managing and treating conditions associated with hyperglycemia.

Sex-Dependent T Cell Dysregulation in Mice with Diet-Induced Obesity

Obesity is an emerging public health problem. Chronic low-grade inflammation is considered a major promotor of obesity-induced secondary diseases such as cardiovascular and fatty liver disease, type 2 diabetes mellitus, and several cancer entities. Most preliminary studies on obesity-induced immune responses have been conducted in male rodents. Sex-specific differences between men and women in obesity-induced immune dysregulation have not yet been fully outlined but are highly relevant to optimizing prevention strategies for overweight-associated complications. In this study, we fed C57BL/6 female vs. male mice with either standard chow or an obesity-inducing diet (OD). Blood and spleen immune cells were isolated and analyzed by flow cytometry. Lean control mice showed no sex bias in systemic and splenic immune cell composition, whereas the immune responses to obesity were significantly distinct between female and male mice. While immune cell alterations in male OD mice were characterized by a significant reduction in T cells and an increase in myeloid-derived suppressor cells (MDSC), female OD mice displayed preserved T cell numbers. The sex-dependent differences in obesity-induced T cell dysregulation were associated with varying susceptibility to body weight gain and fatty liver disease: Male mice showed significantly more hepatic inflammation and histopathological stigmata of fatty liver in comparison to female OD mice. Our findings indicate that sex impacts susceptibility to obesity-induced T cell dysregulation, which might explain sex-dependent different incidences in the development of obesity-associated secondary diseases. These results provide novel insights into the understanding of obesity-induced chronic inflammation from a sex-specific perspective. Given that most nutrition, exercise, and therapeutic recommendations for the prevention of obesity-associated comorbidities do not differentiate between men and women, the data of this study are clinically relevant and should be taken into consideration in future trials and treatment strategies.

Evidence That Peripheral Leptin Resistance in Omental Adipose Tissue and Liver Correlates with MASLD in Humans

Leptin regulates lipid metabolism, maximizing insulin sensitivity; however, peripheral leptin resistance is not fully understood, and its contribution to metabolic dysfunction-associated steatotic liver disease (MASLD) is unclear. This study evaluated the contribution of the leptin axis to MASLD in humans. Forty-three participants, mostly female (86.04%), who underwent cholecystectomy were biopsied. Of the participants, 24 were healthy controls, 8 had MASLD, and 11 had metabolic dysfunction-associated steatohepatitis (MASH). Clinical and biochemical data and the gene expression of leptin, leptin receptor (LEPR), suppressor of cytokine signaling 3 (SOCS3), sterol regulatory element-binding transcription factor 1 (SREBF1), stearoyl-CoA desaturase-1 (SCD1), and patatin-like phospholipase domain-containing protein 2 (PNPLA2), were determined from liver and adipose tissue. Higher serum leptin and LEPR levels in the omental adipose tissue (OAT) and liver with MASH were found. In the liver, LEPR was positively correlated with leptin expression in adipose tissue, and SOCS3 was correlated with SREBF1-SCD1. In OAT, SOCS3 was correlated with insulin resistance and transaminase enzymes (p < 0.05 for all. In conclusion, we evidenced the correlation between the peripheral leptin resistance axis in OAT-liver crosstalk and the complications of MASLD in humans.

Diet switch pre-vaccination improves immune response and metabolic status in formerly obese mice

Metabolic disease is epidemiologically linked to severe complications upon influenza virus infection, thus vaccination is a priority in this high-risk population. Yet, vaccine responses are less effective in these same hosts. Here we examined how the timing of diet switching from a high-fat diet to a control diet affected influenza vaccine efficacy in diet-induced obese mice. Our results demonstrate that the systemic meta-inflammation generated by high-fat diet exposure limited T cell maturation to the memory compartment at the time of vaccination, impacting the recall of effector memory T cells upon viral challenge. This was not improved with a diet switch post-vaccination. However, the metabolic dysfunction of T cells was reversed if weight loss occurred 4 weeks before vaccination, restoring a functional recall response. This corresponded with changes in the systemic obesity-related biomarkers leptin and adiponectin, highlighting the systemic and specific effects of diet on influenza vaccine immunogenicity.

Macrophage and T cell networks in adipose tissue

The signals and structure of the tissues in which leukocytes reside critically mould leukocyte function and development and have challenged our fundamental understanding of how to define and categorize tissue-resident immune cells. One specialized tissue niche that has a powerful effect on immune cell function is adipose tissue. The field of adipose tissue leukocyte biology has expanded dramatically and has revealed how tissue niches can shape immune cell function and reshape them in a setting of metabolic stress, such as obesity. Most notably, adipose tissue macrophages and T cells are under intense investigation due to their contributions to adipose tissue in the lean and obese states. Both adipose tissue macrophages and T cells have features associated with the metabolic function of adipose tissue that are distinct from features of macrophages and T cells that are classically characterized in other tissues. This Review provides state-of-the-art understanding of adipose tissue macrophages and T cells and discusses how their unique niche can help us to better understand diversity in leukocyte responses.

CCL22 and Leptin associated with steroid resistance in childhood idiopathic nephrotic syndrome

Objective

Previous studies have indicated a decrease in T regulatory cells (Tregs) among patients with steroid-resistant nephrotic syndrome. CCL22 and Leptin influenced the immune function of Tregs through their respective pathways. This study aimed to compare patients with steroid-sensitive nephrotic syndrome (SSNS) and steroid-resistant nephrotic syndrome (SRNS) in terms of CCL22 and Leptin levels.

Methods

This prospective study included 117 children diagnosed with idiopathic nephrotic syndrome (INS). Peripheral blood samples were collected before initiating steroid therapy, and serum levels of CCL22 and Leptin were measured. Patients were categorized into three groups based on their response to steroid treatment. Renal biopsies were recommended for all children diagnosed with INS, with higher acceptance rates in glucocorticoid resistance patients.

Results

Based on the response to steroid treatment, 117 children were divided as groups of SSNS (82 cases), frequent relapse nephrotic syndrome (FRNS) (10 cases), and SRNS (25 cases). A total of 41 patients underwent kidney biopsy, 11 cases (13.4%) in SSNS, 7 cases (70.0%) in FRNS and 24 cases (96.0%) in SRNS. 30 cases were minimal change disease (MCD), 9 cases were mesangial proliferative glomerulonephritis (MsPGN) and 3 cases were focal segmental glomerulosclerosis (FSGS). The levels of Leptin were significantly higher in SR patients (1208.1 ± 1044.1 pg/ml) compared to SS patients (515.4 ± 676.9 pg/ml) and controls (507.9 ± 479.8 pg/ml), regardless of the pathological type. CCL22 levels were significantly elevated in SRNS (92.2 ± 157.0 pg/ml), but the difference seemed to be attributed to the specific type of pathology, such as Minimal change disease (MCD) (127.4 ± 206.7 pg/ml) and focal segmental glomerulosclerosis (FSGS) (114.8 ± 22.0 pg/ml). For SRNS prediction, the AUC of Leptin, CCL22, and the joint prediction index were 0.764, 0.640, and 0.806, respectively.

Conclusion

Serum levels of CCL22 and Leptin, detected prior to steroid therapy, were associated with steroid resistance in childhood INS.