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• Eating low-fat yogurt for 4 weeks had a minor impact on circulating immune markers. • The isocaloric nondairy control food increased regulatory T cells but lowered interleukin-10. • Yogurt consumption maintained the regulatory T and helper T-cell proportions. Yogurt consumption may help reduce chronic inflammation associated with obesity. However, the underlying mechanism(s) by which yogurt consumption modulates the immune system have not been validated in human intervention studies. We hypothesized that 4-week yogurt consumption (12 oz/day) attenuates systemic inflammation by modulating the proportion of circulating T helper (Th) 17 and regulatory T (Treg) cells in adult women with elevated body mass index (BMI). To test the hypothesis, we conducted a randomized crossover dietary intervention study consisted of a 4-week dietary intervention in which participants consumed 12 oz of either low-fat dairy yogurt or a soy pudding control snack per day, with a 4-week washout between treatments. Thirty-nine healthy adult women with a BMI between 25 and 40 kg/m2 were enrolled and 20 completed the study. Changes in the biometrics, circulating T cells, and markers of systemic and colonic inflammation were assessed between the 2 treatment groups, as well as 24-hour diet recalls were conducted at baseline and following each treatment. The primary study outcome, the change in the proportion of circulating Th17 cells, was unaffected by the treatments. Secondary outcome measures, circulating Treg, Th17, and markers of chronic inflammation, were maintained by yogurt treatment, whereas circulating Treg was increased and interleukin-10 was reduced by control snack treatment. However, circulating Treg changes were not associated with changes to other biomarkers of inflammation, implying other immune cells and/or tissues may mediate circulating biomarkers of chronic inflammation. This study was approved by the University of Wisconsin-Madison institutional review board and registered at ClinicalTrials.gov NCT04149418. We hypothesized that 4-week low-fat yogurt consumption (12 oz/day) attenuates systemic inflammation by modulating the proportion of circulating Th17 and Treg cells in adult women with elevated BMI. We conducted a randomized crossover dietary intervention study. Yogurt consumption had a minor impact on the immune cell and cytokine profiles, whereas IL-10 was reduced and Treg was increased by control intervention. Th17, T helper 17; Treg, regulatory T cell; BMI, body mass index; IL, interleukin. [Display omitted] [ABSTRACT FROM AUTHOR]

Simple Summary: T regulatory cells are specialized lymphocytes that prevent excessive immune responses, yet they can suppress beneficial anti-tumor immunity when infiltrating malignant tumors. Osteopontin, a versatile protein produced by various cells, including T lymphocytes, influences both inflammation-related diseases and cancer immunity. Its role in T regulatory cells, however, remains less explored. Our study examined the impact of osteopontin deficiency on T regulatory cells. We generated mice lacking osteopontin in these cells and observed impaired immune suppression capabilities, which resulted in increased tumor-fighting activity against melanoma. These findings emphasize osteopontin's crucial role in T regulatory cell stability and functionality within the tumor microenvironment, providing valuable insights for developing new immunotherapeutic strategies. Foxp3-expressing regulatory T (Treg) cells represent the most highly immunosuppressive cell in the tumor microenvironment (TME) that halts effective anti-tumor immunity. Osteopontin (Opn), an extracellular matrix (ECM) glycophosphoprotein, plays key roles in many types of immune-related diseases and is associated with cancer aggressiveness when expressed by tumor cells. However, its role in Foxp3Treg heterogeneity, function, and stability in the TME is poorly defined. We generated mice with a Foxp3-specific deletion of Opn and assessed the ability of Opn-deficient Tregs to suppress inflammation. As these mice aged, they developed a scurfy-like syndrome characterized by aberrant and excessive activation of effector T cells. We evaluated and further confirmed the reduced suppressive capacity of Opn-deficient Tregs in an in vivo suppression assay of colitis. We also found that mice with Opn-deficient Foxp3+ Tregs have enhanced anti-tumor immunity and reduced tumor burden, associated with an unstable Treg phenotype, paralleled by reduced Foxp3 expression in tumor-infiltrating lymphocytes. Finally, we observed reduced Foxp3 and Helios expression in Opn-deficient Tregs compared to wild-type controls after in vitro activation. Our findings indicate that targeting Opn in Tregs reveals vigorous and effective ways of promoting Treg instability and dysfunction in the TME, facilitating anti-tumor immunity. [ABSTRACT FROM AUTHOR]

Objective: Transforming growth factor-beta (TGF-β), an anti-inflammatory cytokine, plays a crucial role in restraining the proliferation and differentiation of T effector cells in autoimmune diseases. Glycoprotein A repetitions predominant (GARP), belonging to the leucine-rich repeat protein family, functions in facilitating the presentation of TGF-β on the surface of regulatory T-cells. The study aims to evaluate the activity of regulatory T-cell in Iraqi patients with psoriasis, treated with topical and biological therapy considering the level of TGF-β1 and LRRC32 gene (GARP) expression. Materials and Methods: In this study 22 blood samples of psoriasis patients and 24 healthy samples as a control group were analyzed to measure the level of TGF-β1 by enzyme-linked immunosorbent assay and the gene expression level of the LRRC32 (GARP gene) by quantitative reverse transcription polymerase chain reaction technique. Results: The results showed a significant decrease (p=0.004) in the level of TGF-β1 in the serum of patients with psoriasis treated with topical therapy and others treated with biological therapy compared to the control group. A significant increase (p=0.05) in the folding of LRRC32 gene expression was detected in psoriasis patients compared to the control percentage (100%). Moreover, there was a significant increase (p=0.000) in the percentage of the gene expression folding of LRRC32 gene in patients treated with biological therapy and patients treated with topical therapy compared to control percentage (100%). Conclusions: The high expression of the LRRC32 gene in patient samples is an indication of the effective role of regulatory T-cells under biological and topical treatment. [ABSTRACT FROM AUTHOR]

Background: Postmenopausal osteoporosis (PMO) is a chronic condition characterized by decreased bone strength. This study aims to investigate the effects and mechanisms of the combination of Butyricicoccus pullicaecorum (Bp) and 3-hydroxyanthranilic acid (3-HAA) on PMO. Methods: The effects of Bp and 3-HAA on PMO were evaluated in ovariectomized (OVX) rats by assessing stereological parameters, femur microstructure, and autophagy levels. The T helper (Th) 17/Regulatory T (Treg) cells of rats were detected using flow cytometric analysis. Furthermore, the impact of Bp and 3-HAA on the gut microbiota of rats was assessed using 16S rRNA gene sequencing. The correlation between the gut microbiota of rats and Th17/Treg immune factors, as well as femoral stereo parameters, was separately assessed using Spearman rank correlation analysis. Results: Bp and 3-HAA treatments protected OVX rats by promoting osteogenesis and inhibiting autophagy. Compared to the Sham group, OVX rats showed an increase in Th17 cells and a decrease in Treg cells. Bp and 3-HAA reversed these changes. Enterorhabdus and Pseudomonas were significantly enriched in OVX rats. Bp and 3-HAA regulated the gut microbiota of OVX rats, enriching pathways related to nutrient metabolism and immune function. There was a correlation between the gut microbiota and the Th17/Treg, as well as femoral stereo parameters. The concurrent administration of Bp and 3-HAA medication facilitated the enrichment of gut microbiota associated with the improvement of PMO. Conclusion: The combination therapy of Bp and 3-HAA can prevent PMO by modulating the gut microbiota and restoring Th17/Treg immune homeostasis. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated that Th1 cytokines like IL-2, IL-12 and IFN-γ have initiatory role in alopecia areata (AA) and positive correlation with disease severity. They informed that serum levels of Th17 cytokines, IL-17, IL-22, IL-23 increased in active AA patients and corelated, particularly IL-17, with disease severity. In recent reports it was showed the balance between Th17 and Treg cells is crucial for maintaining tolerance to self-antigens, and an imbalance towards Th17 may contribute to the development of autoimmune diseases like AA. But research on serum Treg markers in AA is limited. It was aimed to investigate whether the Treg cells have a role in the pathogenesis of AA analyzing the serum levels of Treg cytokines IL-35 and TGF-β in the patients with AA. 42 AA patients and 38 healthy controls were enrolled. Patient demographics, clinical data, disease severity assessed by Severity of Alopecia Tool (SALT) scores were recorded. Serum samples were collected and analyzed for TGF-β and IL-35 levels using ELISA kits. The cytokine levels in both groups were statistically compared. Their relation with parameters of demographic and severity of disease was evaluated. The patient and control groups had no statistically significant difference, there was 71.4% males and 28.6% females in patient group, while the control group had 63.2% males and 36.8% females, Severity analysis classified 18 patients with mild AA, 19 with moderate AA, and 5 with alopecia totalis/areata universalis. While TGF-β levels exhibited no significant difference between groups, IL-35 levels were significantly elevated in AA patients (p = 0.002). Logistic regression identified IL-35 as a significant parameter influencing disease status (OR = 1.055). Correlation analysis revealed a weak positive correlation between patient age and IL-35 levels (r = 0.436; p = 0.004). Notably, IL-35 levels displayed a significant decrease in individuals with antinuclear antibody (ANA) positivity. No correlations were identified between cytokine levels and disease severity, prognosis, or disease activity. Elevated IL-35 levels suggest that IL-35 and specific Treg cell subsets can play a role in AA pathogenesis. The nuanced roles of TGF-β and IL-35 highlight the need for comprehensive studies to interpret their implications in the complex immunopathogenesis of AA. These findings open avenues for further research, positioning IL-35 as a prospective target for investigating and potentially intervening in AA pathogenesis. [ABSTRACT FROM AUTHOR]

Regulatory T cells (Treg) play a prominent role in utero tolerating non-inherited maternal antigens and in regulating immune responses against pathogens at birth. This study investigates Treg immunity in newborns in West Africa, where sepsis remains a major public health problem. Treg phenotypes on neonates subgroups with early-onset sepsis (EOS), presumed sepsis, and healthy newborn with and without prenatal risk factors were evaluated. Treg phenotypes varied according to prenatal conditions, with increase in Treg frequency and Foxp3 expression in healthy newborns with prenatal risk factors compared to those with none risk. Compared to healthy newborns with prenatal risk factors, EOS neonates had a significantly reduced frequency of Treg and Foxp3 expression. In the Treg pool, higher frequency of activated Treg was observed in EOS neonates, suggesting an in-utero activation upstream of the sepsis onset. Their migration to the infection site may explain the reduced frequency of circulating Integrin α4β1+ Treg suggestive of homing to the endothelial tissue. EOS neonates show increases expression of CTLA-4, PD-1 and CD39 on Treg, which negatively regulate the activation of effector T cells (Teff) corroborating by the lower frequency of Teff in EOS neonates. The higher frequency of CD39+ Treg and the lower frequency of integrinα4β1+ Treg in EOS non-survivor suggests that Treg exhaustement and endothelial homing are associated with outcome severity. Neonates developing EOS are born with an altered Treg phenotypic profile. Treg expression of CTLA-4, PD-1, CD39, and integrinα4β1 cell markers can be considered as early warning or diagnostic markers of EOS. [ABSTRACT FROM AUTHOR]

Objective: To explore the role of different cells and molecules in the pathogenesis of allergic rhinitis (AR) with positive Artemisia allergen by detecting their expression levels. Methods: From January 2021 to December 2022,200 AR patients diagnosed in the Otolaryngology Clinic of Ordos Central Hospital were selected as the AR group, and 50 healthy people who underwent physical examination in the hospital during the same period were randomly selected as the healthy control (HC) group. The levels of GATA-3mRNA, RORγtmRNA and FoxP3mRNA in peripheral blood mononuclear cells were detected by real-time fluorescence quantitative PCR (qRT-PCR). The proportions of Th2, Th17 and Treg cells were detected by flow cytometry. The concentrations of IL-4, IL-5, IL-17 and IL-10 in serum were detected by enzyme-linked immunosorbent assay. The differences of transcription gene level, immune cell ratio and cytokine concentration between the two groups were analyzed. Results: There was no difference in age and gender between the two groups. The levels of GATA-3mRNA and RORγtmRNA transcription genes in peripheral blood mononuclear cells, the percentage of Th2, Th17 and Treg immune cells, the levels of eosinophils and basophils in peripheral blood, the concentrations of IL-4, IL-5, IL-17, IL-10 cytokines and IgE in serum of AR patients were significantly higher than those in HC group (P < 0.05). IL-4 and IL-17 were positively correlated with total IgE level. Conclusion: The secretion of immune cells and cytokines in peripheral blood of AR patients is abnormal. Th2, Th17, Treg specific transcription factors and related cells and cytokines are involved in the occurrence and development of allergic rhinitis. [ABSTRACT FROM AUTHOR]

Objectives: Predicting the efficacy of biological disease–modifying antirheumatic drugs is challenging. In this study, we aimed to explore markers that predict the efficacy of abatacept in rheumatoid arthritis (RA) patients. Methods: Thirty RA patients receiving abatacept were recruited, and peripheral blood mononuclear cells from the participants were subjected to DNA microarray analysis. The expression of CC chemokine receptor 4 (CCR4), which was selected by the result of DNA microarray, was determined by flow cytometry in 16 newly diagnosed treatment-naïve RA patients. CCR4 expression on each helper T-cell subset was also measured. Results: CCR4 was upregulated in the abatacept responder. The expression levels of CCR4 were significantly correlated with the improvement of the Clinical Disease Activity Index. CCR4 expression was predominantly observed in CD4+ T cells in peripheral blood mononuclear cells. The percentage of CCR4-expressing CD4+ T cells was significantly higher in RA patients than in healthy individuals. Interestingly, Th17 and Treg cells expressed high levels of CCR4 compared to non-Th17-related helper T cells. Conclusions: CCR4 is a Th17- and Treg-related gene, and the high CCR4 expression in peripheral blood samples may predict the efficacy of abatacept in RA. [ABSTRACT FROM AUTHOR]

Vaccines are the most effective and feasible way to control pathogen infection. Helminths have been reported to jeopardize the protective immunity mounted by several vaccines. However, there are no experimental data about the effect of helminth infection on the effectiveness of COVID-19 vaccines. Here, a mouse model of trichinosis, a common zoonotic disease worldwide, was used to investigate effects of Trichinella spiralis infection on the RBD protein vaccine of SARS-CoV-2 and the related immunological mechanism, as well as the impact of albendazole (ALB) deworming on the inhibitory effect of the parasite on the vaccination. The results indicated that both the enteric and muscular stages of T. spiralis infection inhibited the vaccine efficacy, evidenced by decreased levels of IgG, IgM, sIgA, and reduced serum neutralizing antibodies, along with suppressed splenic germinal center (GC) B cells in the vaccinated mice. Pre-exposure to trichinosis promoted Th2 and/or Treg immune responses in the immunized mice. Furthermore, ALB treatment could partially reverse the inhibitory effect of T. spiralis infection on the efficiency of the vaccination, accompanied by a restored proportion of splenic GC B cells. Therefore, given the widespread prevalence of helminth infections worldwide, deworming therapy needs to be considered when implementing COVID-19 vaccination strategies. [ABSTRACT FROM AUTHOR]

The miR-15/16 family targets a large network of genes in T cells to restrict their cell cycle, memory formation, and survival. Upon T cell activation, miR-15/16 are downregulated, allowing rapid expansion of differentiated effector T cells to mediate a sustained response. Here, we used conditional deletion of miR-15/16 in regulatory T cells (Tregs) to identify immune functions of the miR-15/16 family in T cells. miR-15/16 are indispensable to maintain peripheral tolerance by securing efficient suppression by a limited number of Tregs. miR-15/16 deficiency alters expression of critical Treg proteins and results in accumulation of functionally impaired FOXP3loCD25loCD127hi Tregs. Excessive proliferation in the absence of miR-15/16 shifts Treg fate and produces an effector Treg phenotype. These Tregs fail to control immune activation, leading to spontaneous multi-organ inflammation and increased allergic inflammation in a mouse model of asthma. Together, our results demonstrate that miR-15/16 expression in Tregs is essential to maintain immune tolerance.

Amyotrophic Lateral Sclerosis (ALS) is a poorly understood and fatal disease. It has a low prevalence and a 2–4 year survival period. Various theories and hypotheses relating to its development process have been proposed, albeit with no breakthrough in its treatment. Recently, the role of the adaptive immune system in ALS, particularly CD4+ T cells, has begun to be investigated. CD4+ T cells are a heterogeneous group of immune cells. They include highly pro-inflammatory types such as Th1 and Th17, as well as highly anti-inflammatory cells such as Tregs. However, the landscape of the role of CD4+ T cells in ALS is still not clearly understood. This review covers current hypotheses that elucidate how various CD4+ T cells can contribute to ALS development. These hypotheses include the SWITCH model, which suggests that, in the early stages of the disease, Tregs are highly capable of regulating the immune response. However, in the later stages of the disease, it seems that pro-inflammatory cells such as Th1 and Th17 are capable of overwhelming Treg function. The reason why this occurs is not known. Several research groups have proposed that CD4+ T cells as a whole might experience aging. Others have proposed that gamma delta T cells might directly target Tregs. Additionally, other research groups have argued that less well-known CD4+ T cells, such as Emoes+ CD4+ T cells, may be directly responsible for neuron death by producing granzyme B. We propose that the ALS landscape is highly complicated and that there is more than one feasible hypothesis. However, it is critical to take into consideration the differences in the ability of different populations of CD4+ T cells to infiltrate the blood–brain barrier, taking into account the brain region and the time of infiltration. Shedding more light on these still obscure factors can help to create a personalized therapy capable of regaining the balance of power in the battle between the anti-inflammatory and pro-inflammatory cells in the central nervous system of ALS patients.

Sarcoidosis is a multisystem inflammatory disease of unknown etiology characterized by the formation of non-caseating granulomas, most commonly in the lung tissue. It presents with two main forms: acute and chronic. Patients with chronic sarcoidosis tend to have a less favorable prognosis with a risk of developing lung fibrosis. Sarcoidosis development involves the activation of T cells, which release various chemokines and cytokines that stimulate the inflammatory process. The aim of our study was to investigate the role of the ratio between Th17 and Treg cells in the chronic course of sarcoidosis. We studied peripheral blood plasma samples from patients with chronic sarcoidosis (CS) (n = 101) and healthy individuals (HC) (n = 40). The diagnosis in CS patients was confirmed by histological methods. We determined the levels of Th17 and Treg (% of total lymphocytes) by flow cytometry. The concentration of cytokines (pg/ml) IL-17A and IL-10 was measured by multiplex analysis using Luminex xMap. Correlations between the Th17/Treg ratio and clinical parameters, including serum angiotensin-converting enzyme (sACE) activity level in the peripheral blood, forced expiratory volume in the first second (FEV1, %), fibrosis manifestations, and extrapulmonary manifestations were analyzed in CS patients. Our analysis revealed elevated levels of Th17 cells (p = 0.028) and decreased Treg levels (p = 0.026) in CS patients compared to healthy controls. This resulted in a significantly increased Th17/Treg ratio (p = 0.003) and IL-17A/IL-10 ratio (p < 0.001) in sarcoidosis patients. Furthermore, the Th17/Treg ratio positively correlated with sACE levels (p = 0.018), fibrosis manifestations (p = 0.019), and extrapulmonary manifestations (p = 0.016), and negatively correlated with FEV1% (p = 0.021). Our results indicate an increase in the Th17/Treg ratio, as well as the ratio of their main cytokines in patients with chronic sarcoidosis, which may emphasize their potential role as a diagnostic and prognostic biomarker of disease severity. At the molecular level, the balance between Treg and Th17 cells is maintained by the transcription factors Foxp3 and RORγt, which regulate the differentiation and function of these cells. Disruption of this balance in patients with chronic sarcoidosis may indicate a possible mechanism for disease progression.

Abstract Objective To explore the role of different cells and molecules in the pathogenesis of allergic rhinitis (AR) with positive Artemisia allergen by detecting their expression levels. Methods From January 2021 to December 2022,200 AR patients diagnosed in the Otolaryngology Clinic of Ordos Central Hospital were selected as the AR group, and 50 healthy people who underwent physical examination in the hospital during the same period were randomly selected as the healthy control (HC) group. The levels of GATA-3mRNA, RORγtmRNA and FoxP3mRNA in peripheral blood mononuclear cells were detected by real-time fluorescence quantitative PCR (qRT-PCR). The proportions of Th2, Th17 and Treg cells were detected by flow cytometry. The concentrations of IL-4, IL-5, IL-17 and IL-10 in serum were detected by enzyme-linked immunosorbent assay. The differences of transcription gene level, immune cell ratio and cytokine concentration between the two groups were analyzed. Results There was no difference in age and gender between the two groups. The levels of GATA-3mRNA and RORγtmRNA transcription genes in peripheral blood mononuclear cells, the percentage of Th2, Th17 and Treg immune cells, the levels of eosinophils and basophils in peripheral blood, the concentrations of IL-4, IL-5, IL-17, IL-10 cytokines and IgE in serum of AR patients were significantly higher than those in HC group (P

Qing-Hui Li,1,2 Qiu-Yan Zhao,1 Wei-Jing Yang,1 Ai-Fang Jiang,2 Chun-E Ren,2 Yu-Han Meng2 1School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261021, People’s Republic of China; 2Center of Reproductive Medicine, Affiliated Hospital of Shandong Second Medical University, Weifang, Shandong, 261000, People’s Republic of ChinaCorrespondence: Yu-Han Meng, Center of Reproductive Medicine, Affiliated Hospital of Shandong Second Medical University, No. 2428.Yuhe Road, Kuiwen District, Weifang, Shandong, 261031, People’s Republic of China, Tel/Fax +86 536-3081389, Email yhmeng6@163.comAbstract: Recurrent spontaneous abortion (RSA) is defined as two or more consecutive pregnancy failures, which brings tremendous stress to women of childbearing age and seriously affects family well-being. However, the reason in about 50% of cases remains unknown and is defined as unexplained recurrent spontaneous abortion (URSA). The immunological perspective in URSA has attracted widespread attention in recent years. The embryo is regarded as a semi-allogeneic graft to the mother. A successful pregnancy requires transition to an immune environment conducive to embryo survival at the maternal–fetal interface. As an important member of regulatory immunity, regulatory T (Treg) cells play a key role in regulating immune tolerance at the maternal–fetal interface. This review will focus on the phenotypic plasticity and lineage stability of Treg cells to illustrate its relationship with URSA.Keywords: immune homeostasis, Treg cells, phenotype, maternal–fetal tolerance

Abstract More than 80% of patients with myasthenia gravis (MG) are positive for anti-acetylcholine receptor (AChR) antibodies. Regulatory T cells (Tregs) suppress overproduction of these antibodies, and patients with AChR antibody-positive MG (AChR MG) exhibit impaired Treg function and reduced Treg numbers. The gut microbiota and their metabolites play a crucial role in maintaining Treg differentiation and function. However, whether impaired Tregs correlate with gut microbiota activity in patients with AChR MG remains unknown. Here, we demonstrate that butyric acid-producing gut bacteria and serum butyric acid level are reduced in patients with AChR MG. Butyrate supplementation effectively enhanced Treg differentiation and their suppressive function of AChR MG. Mechanistically, butyrate activates autophagy of Treg cells by inhibiting the mammalian target of rapamycin. Activation of autophagy increased oxidative phosphorylation and surface expression of cytotoxic T-lymphocyte-associated protein 4 on Treg cells, thereby promoting Treg differentiation and their suppressive function in AChR MG. This observed effect of butyrate was blocked using chloroquine, an autophagy inhibitor, suggesting the vital role of butyrate-activated autophagy in Tregs of patients with AChR MG. We propose that gut bacteria derived butyrate has potential therapeutic efficacy against AChR MG by restoring impaired Tregs.

Abstract Background Regulatory T cells (Tregs) are crucial in maintaining immune homeostasis and preventing autoimmunity and inflammation. A proportion of Treg cells can lose Foxp3 expression and become unstable under inflammation conditions. The precise mechanisms underlying this phenomenon remain unclear. Methods The PI16 gene knockout mice (PI16fl/flFoxp3Cre) in Treg were constructed, and the genotypes were identified. The proportion and phenotypic differences of immune cells in 8-week-old mice were detected by cell counter and flow cytometry. Two groups of mouse Naïve CD4+T cells were induced to differentiate into iTreg cells to observe the effect of PI16 on the differentiation and proliferation of iTreg cells, CD4+CD25+Treg and CD4+CD25− effector T cells (Teff) were selected and co-cultured with antigen presenting cells (APC) to observe the effect of PI16 on the inhibitory ability of Treg cells in vitro. The effects of directed knockout of PI16 in Treg cells on inflammatory symptoms, histopathological changes and immune cell expression in mice with enteritis and autoimmune arthritis were observed by constructing the model of antigen-induced arthritis (AIA) and colitis induced by dextran sulfate sodium salt (DSS). Results We identified peptidase inhibitor 16 (PI16) as a negative regulator of Treg cells. Our findings demonstrate that conditional knock-out of PI16 in Tregs significantly enhances their differentiation and suppressive functions. The conditional knockout of the PI16 gene resulted in a significantly higher abundance of Foxp3 expression (35.12 ± 5.71% vs. 20.00 ± 1.61%, p = 0.034) in iTreg cells induced in vitro compared to wild-type mice. Mice with Treg cell-specific PI16 ablation are protected from autoimmune arthritis (AIA) and dextran sulfate sodium (DSS)-induced colitis development. The AIA model of PI16CKO is characterized by the reduction of joint structure and the attenuation of synovial inflammation and in DSS-induced colitis model, conditional knockout of the PI16 reduce intestinal structural damage. Additionally, we found that the deletion of the PI16 gene in Treg can increase the proportion of Treg (1.46 ± 0.14% vs. 0.64 ± 0.07%, p

The mortality of hepatocellular carcinoma (HCC) is on the rise globally, particularly in the Western world, with etiology gradually shifting from virus-related liver diseases to metabolic disorders such as non-alcoholic fatty liver disease. Early detection of HCC is challenging, and effective prognostic indicators are currently lacking, urgently necessitating reliable markers to assist in treatment planning and clinical management. Here, we introduce hepatocellular carcinoma senescence genes (HSG) to assess cellular senescence in HCC and devise a hepatocellular carcinoma senescence score (HSS) for prognostic prediction. Higher HSS levels signify poorer prognosis and increased tumor proliferation activity. Additionally, we observe alterations in the tumor immune microenvironment with higher HSS levels, such as increased infiltration of Treg, potentially providing a basis for immunotherapy. Furthermore, we identify key genes, such as PTTG1, within the senescence gene set and demonstrate their regulatory roles in HCC cells and Treg through experimentation. In summary, we establish a scoring system based on hepatocellular carcinoma senescence genes for prognostic prediction in HCC, potentially offering guidance for clinical treatment planning. [ABSTRACT FROM AUTHOR]

The spleen plays a role in innate and adaptive immunity, and autoimmune diseases like rheumatoid arthritis (RA). We investigated the effect of splenectomy in early and moderate stages of autoimmune arthritis in a mouse model. To induce recombinant human G1-induced arthritis (GIA), BALB/c mice were immunized intraperitoneally three times in 4-week intervals with the rhG1 antigen. Mice were splenectomized on day 7 (SPE1) or day 35 (SPE2) after the initiation of immunization; tested for clinical severity, joint radiological and histological changes, serum levels of inflammatory cytokines and autoantibodies, and rhG1-specific immune responses; and compared to those in control mice with spleen left intact. Circulating Tregs and T-helper subset ratios in the spleen and inguinal lymph nodes (LNs) were also examined using flow cytometry. The onset of severe inflammatory response was significantly delayed in SPE1 and SPE2 groups compared to control mice at early stages of GIA, which was associated with increased circulating Tregs. After the third immunization, as disease progressed, the severity scores were robustly increased in all mice. Nevertheless, in splenectomized mice, we observed reduced joint deterioration and cartilage damage, more Th2 cells in LNs, and reduced levels of pro-inflammatory cytokines and autoantibodies in their sera. Mesenteric LN cells of splenectomized mice exhibited weaker response in vitro against the rhG1 antigen compared to control mice spleen. In conclusion, splenectomy in the early stages of GIA delayed the inflammatory response, suggesting a protective effect against the development and progression of severe destructive arthritis. We propose that splenectomy in early stages of autoimmune arthritis could be beneficial because it prevents bone and cartilage destruction in the joints. This might be mediated through increasing the circulating Treg frequency and decreasing the Th1/Th17 polarization which could contribute to reduced serum levels of pro-inflammatory cytokines and pathological autoantibodies. Graphical Abstract [ABSTRACT FROM AUTHOR]

Osteoporosis (OP) is a chronic systemic metabolic bone disease. In recent years, with development of population aging, incidence of OP is also increasing, bringing huge economic burden to family and society. There are many causes of OP, such as aging, oxidative stress, epigenetic and many other aspects, and with further development of research, inflammatory factors and other bone immunology into people's vision. Th17 cells are effector T cell subpopulation that induce development of inflammation and promote bone loss. On the contrary, Treg can maintain their own tolerance and further suppress their own immunity, thus playing a bone protective role. Under physiological conditions, Th17/Treg balance can maintain bone homeostasis, while under pathological conditions, disruption of Th17/Treg balance can lead to bone loss. Based on this, this paper will review pathways and cytokines mediating Th17/Treg balance in OP, in order to provide new ideas and methods for treatment of OP. [ABSTRACT FROM AUTHOR]

Introduction: We investigated the function of type 2 innate lymphoid cells (ILC2s) and IL-33 in pulmonary tuberculosis (PTB). Methodology: Peripheral blood samples were collected from PTB patients and healthy controls. The cytometric bead array was used to detect plasma IL-33, TGF-β, IL-4, IL-5, IL-6, IL-10, IL-13, and soluble ST2 (sST2). ILC2s, Th2, and Treg cells were detected with flow cytometry. Quantitative real-time PCR was used to measure mRNA levels. ILC2s were co-cultured with peripheral blood mononuclear cells and then intervened with IL-33 or anti-ST2 antibody + IL-33 in vitro. IL-4, IL-6, IL-5, IL-10, IL-13, and TGF-β levels were measured by enzyme-linked immunosorbent assay. Results: Compared with healthy controls, the levels of IL-33, sST2, TGF-β, IL-10, and IL-6 in the plasma of PTB patients were significantly higher. No significant difference was found in the plasma IL-4, IL-5, and IL-13 levels. Patients with PTB had significantly increased ILC2s proportion and mRNA levels of RAR-related orphan receptor α and GATA binding protein 3. After 48 h of IL-33 stimulation in vitro, Treg cell proportion significantly increased and the IL-10 level was significantly elevated. Treatment with anti-ST2 abolished these effects. No significant difference was found in cytokines of IL-4, IL-6, IL-5, IL-13, and TGF-β, or Th2 cells before and after IL-33 treatment. ILC2s proportion in peripheral blood was increased and plasma IL-33 was upregulated in PTB patients. Conclusions: IL-33 may promote the growth of ILC2s and the production of Treg-related cell cytokines, but not Th2-related cell cytokines, to participate in immune response to PTB. [ABSTRACT FROM AUTHOR]

The bleomycin-induced scleroderma model is a well-established and dependable method for creating a mouse model of SSc (systemic sclerosis). In the field of skin connective tissue diseases, increasing evidence from clinical and animal experiments suggests that TLRs (Toll-like receptors) play an important role in several diseases. This study aimed to determine the role of TLR7 (Toll-like receptor 7) and TLR9 (Toll-like receptor 9) in the mechanisms of immune abnormalities and fibrosis in SSc. This study used TLR7-KO mice (TLR7-knockout mice with a balb/c background) and TLR9-KO mice (TLR9-knockout mice with a balb/c background) as well as WT mice (wild-type balb/c mice). All three kinds of mice were induced by BLM (bleomycin) in a scleroderma model as the experimental group; meanwhile, WT mice treated with PBS (phosphate-buffered saline) were used as the control group. We analyzed the fibrotic phenotype and the immunological abnormality phenotype of TLR7-deficient and TLR9-deficient mice in the SSc disease model using flow cytometry, RT-PCR (reverse transcription–polymerase chain reaction), a histological examination, and IHC (immunohistochemical staining). In a mouse model of SSc disease, the deletion of TLR7 attenuated skin and lung fibrosis, while the deletion of TLR9 exacerbated skin and lung fibrosis. The deletion of TLR7 resulted in a relative decrease in the infiltration and expression of various pro-inflammatory and fibrotic cells and cytokines in the skin. On the other hand, the deletion of TLR9 resulted in a relative increase in the infiltration and expression of various pro-inflammatory and cytokine-inhibiting cells and cytokines in the skin. Under the influence of pDCs (plasmacytoid dendritic cells), the balances of Beff/Breg (IL-6 + CD19 + B cell/IL-10 + CD19 + B cell), Th17/Treg (IL-17A + CD4 + T cell/Foxp3 + CD25 + CD4 + T cell), M1/M2 (CD86 + macrophage/CD206 + macrophage), and Th1/Th2 (TNFα + CD3 + CD4 + T cell/IL-4 + CD3 + CD4 + T cell) were biased towards the suppression of inflammation and fibrosis as a result of the TLR7 deletion. Comparatively, the balance was biased towards promoting inflammation and fibrosis due to the TLR9 deletion. In the SSc model, TLR7 promoted inflammation and fibrosis progression, while TLR9 played a protective role. These results suggest that TLR7 and TLR9 play opposite roles in triggering SSc to produce immune system abnormalities and skin fibrosis. [ABSTRACT FROM AUTHOR]

Sepsis is a systemic inflammatory response syndrome caused by trauma or infection, which can lead to multiple organ dysfunction. In severe cases, sepsis can also progress to septic shock and even death. Effective treatments for sepsis are still under development. This study aimed to determine if targeting the PI3K/Akt signaling with CAL-101, a PI3K p110δ inhibitor, could alleviate lipopolysaccharide (LPS)-induced sepsis and contribute to immune tolerance. Our findings indicated that CAL-101 treatment improved survival rates and alleviated the progression of LPS-induced sepsis. Compared to antibiotics, CAL-101 not only restored the Th17/regulatory T cells (Treg) balance but also enhanced Treg cell function. Additionally, CAL-101 promoted type 2 macrophage (M2) polarization, inhibited TNF-α secretion, and increased IL-10 secretion. Moreover, CAL-101 treatment reduced pyroptosis in peritoneal macrophages by inhibiting caspase-1/gasdermin D (GSDMD) activation. This study provides a mechanistic basis for future clinical exploration of targeted therapeutics and immunomodulatory strategies in the treatment of sepsis. • CAL-101 improved the survival rate and alleviated the progression in LPS-induced sepsis compared to antibiotic therapy. • CAL-101 not only rebalanced proportion of Th17/Treg, but also restored the function of Treg cells in LPS-induced sepsis. • CAL-101 promoted the M2 macrophages polarization and reduced pyroptosis by inhibiting the activation of Caspase 1/GSDMD. [ABSTRACT FROM AUTHOR]

Tyrosine kinase inhibitor (TKI) drugs have significantly improved chronic myeloid leukemia (CML) outcomes. Neopeptides from CML cells may induce specific immune responses, which are crucial for deep molecular (DMR) and treatment-free remission (TFR). In this study of Ethiopian patients with CML (n = 162), the HLA alleles and single-nucleotide polymorphisms of five cytokines revealed significant associations with clinical outcomes. Clinically unfavorable outcomes correlated with HLA alleles A*03:01/02, A*23:17:01, B*57:01/02/03, and HLA-DRB4*01:01 (p-value = 0.0347, p-value = 0.0285, p-value = 0.037, and p-value = 0.0127, respectively), while HLA-DRB4*01:03:01 was associated with favorable outcomes (p-value = 0.0058). After assigning values for the 'low', 'intermediate', and 'high' gene expression of the SNPs' respective cytokine genes, Kaplan–Meier estimates for relapse-free survival, adjusted for age, treatment duration, and relapse risk among patients after the administration of TKIs, indicated that a gene expression ratio above the overall median of TNF-α, IL-6, and the combination of TGF-β1/IL-10, IFNγ, and IL-6/IL-10 TGF-β1 was correlated with a higher likelihood of treatment failure ((RR: 3.01; 95% CI: 1.1–8.3; p-value = 0.0261) and (RR: 2.4; 95% CI: 1.1–5.2; p-value = 0.022), respectively). Multi-SNPs, surpassing single-SNPs, and HLA allele polymorphisms showed promise in predicting outcomes of patients with CML during TKI treatment, prompting further exploration into their potential utility. [ABSTRACT FROM AUTHOR]

Dendritic cell (DC)-based vaccines have emerged as a promising strategy in cancer immunotherapy due to low toxicity. However, the therapeutic efficacy of DC as a monotherapy is insufficient due to highly immunosuppressive tumor environment. To address these limitations of DC as immunotherapeutic agent, we have developed a polymeric nanocomplex incorporating (1) oncolytic adenovirus (oAd) co-expressing interleukin (IL)-12 and granulocyte-macrophage colonystimulating factor (GM-CSF) and (2) arginine-grafted bioreducible polymer with PEGylated paclitaxel (APP) to restore antitumor immune surveillance function in tumor milieu and potentiate immunostimulatory attributes of DC vaccine. Nanohybrid complex (oAd/APP) in combination with DC (oAd/APP+DC) induced superior expression level of antitumor cytokines (IL-12, GM-CSF, and interferon gamma) than either oAd/APP or DC monotherapy in tumor tissues, thus resulting in superior intratumoral infiltration of both endogenous and exogenous DCs. Furthermore, oAd/APP+DC treatment led superior migration of DC to secondary lymphoid organs, such as draining lymph nodes and spleen, in comparison with either monotherapy. Superior migration profile of DCs in oAd/APP+DC treatment group resulted in more prolific activation of tumor-specific T cells in these lymphoid organs and greater intratumoral infiltration of T cells. Additionally, oAd/ APP+DC treatment led to lower subset of tumor infiltrating lymphocytes and splenocytes being immunosuppressive regulatory T cells than any other treatment groups. Collectively, oAd/APP+DC led to superior induction of antitumor immune response and amelioration of immunosuppressive tumor microenvironment to elicit potent tumor growth inhibition than either monotherapy. [ABSTRACT FROM AUTHOR]

This study sought to compare the behavior of Treg subsets displaying different coexpression patterns of Neuropilin‐1 (Nrp1) and Helios, under the influence of gut stress unrelated to hematopoietic stem cell transplantation, pretransplantation conditioning, and posttransplant gastrointestinal acute graft versus host disease (GI‐aGvHD). Host CD4+/CD25hi/Foxp3+ Treg cells, identified by flow cytometry, were isolated from various tissues of mice affected by these stressors. Expression of CD25, CTLA‐4, CD39, OX40, integrin‐β7, LAG3, TGFβ/LAP, granzyme‐A, ‐B, and interleukin‐10 was compared in four Treg subsets displaying Helios or Nrp1 only, both or none. Fluorescence‐activated cell sorter–sorted Treg subsets, displaying markers affected in a conditioning‐ and GI‐aGVHD‐restricted manner, were further investigated by transcriptome profiling and T‐cell suppression assays. We found that conditioning by irradiation greatly diminished the relative frequency of Helios+/Nrp1+ Treg, shifting the balance toward Helios−/Nrp1− Treg in the host. Upregulation of integrin‐β7 and OX40 occurred in GI‐aGvHD‐dependent manner in Helios+/Nrp1+ cells but not in Helios−/Nrp1− Treg. Sorted Treg subsets, confirmed to overexpress Nrp1, Helios, OX40, or integrin‐β7, displayed superior immunosuppressive activity and enrichment in activation‐related messenger RNA transcripts. Our data suggest that conditioning‐induced shrinkage of the Nrp1+/Helios+ Treg subset may contribute to the development of GI‐GvHD by impairing gut homing and decreasing the efficiency of Treg‐mediated immunosuppression. [ABSTRACT FROM AUTHOR]

Regulatory T cells (Tregs) are a subset of T cells participating in a variety of diseases including mycoplasmal pneumonia, contagious ecthyma, and so on. The role of Tregs in goat contagious ecthyma is not completely understood due to the lack of species-specific antibodies. Here, we developed a combination of CD4 and CD25 fluorescence monoclonal antibodies (mAb) to recognize goat Tregs and assessed its utility in flow cytometry, immunofluorescence staining. Using immunofluorescence staining, we found that the frequency of Treg cells was positively correlated with the viral load during orf virus infection. These antibodies could serve as important tools to monitor Tregs during orf virus infection in goats. Key points: • A combination of fluorescent mAbs (C11 and D12) was prepared for the detection of goat Tregs. • C11 and D12 are effective in flow cytometry, immunofluorescence staining, and C11 has excellent species specificity. • The frequency of Treg cells was positively correlated with the viral load during orf virus infection. [ABSTRACT FROM AUTHOR]

Natural IgE cytotoxic peptides (nECPs), which are derived from the constant domain of the heavy chain of human IgE producing B cells via endoplasmic reticulum (ER) stress, are decorated onto MHC class 1a molecules (MHCIa) as unique biomarkers for CTL (cytotoxic T lymphocyte)‐mediated immune surveillance. Human IgE exhibits only one isotype and lacks polymorphisms; IgE is pivotal in mediating diverse, allergen‐specific allergies. Therefore, by disrupting self‐IgE tolerance via costimulation, the CTLs induced by nECPs can serve as universal allergy vaccines (UAVs) in humans to dampen IgE production mediated by diverse allergen‐specific IgE‐secreting B cells and plasma cells expressing surface nECP‐MHCIa as targets. The study herein has enabled the identification of nECPs, A32 and SP‐1/SP‐2 nonameric natural peptides produced through the correspondence principle. Vaccination using nECP induced nECP‐specific CTL that profoundly suppressed human IgE production in vitro as well as chimeric human IgE production in human IgE/HLA‐A2.01/HLA‐B7.02 triple transgenic rodents. Furthermore, nECP‐tetramer‐specific CTLs were found to be converted into CD4 Tregs that restored IgE competence via the homeostatic principle, mediatepred by SREBP‐1c suppressed DCs. Thus, nECPs showed causal efficacy and safety as UAVs for treating categorically type I hypersensitivity IgE‐mediated allergies. The applied vaccination concept presented provides the foundation to unify, integrate through a singular class of tetramer‐specific TCR clonotypes for regulaing human IgE production. The three signal theory pertains to mechanisms of three cells underlying central tolerance (S), breaking self tolerance (NS) and regaining peripheral tolerance (S) via homeostasis concerning nECP as an efficacious and safe UAV to treat type I IgE‐mediated hypersensitivity. The three signal theory impirically extended, may be heuritic for immuno‐regulation of adaptive immune repertoire in general. [ABSTRACT FROM AUTHOR]

This article examines the expression of FCRL3 and its correlation with TIGIT in regulatory T cells of patients with systemic lupus erythematosus (SLE). The study used single-cell RNA sequencing and flow cytometry to analyze the expression of FCRL3 and TIGIT in T-cell subsets. The results showed that FCRL3 expression was elevated in Treg cells of SLE patients and positively associated with TIGIT expression. The co-expression of FCRL3 and TIGIT may have clinical significance in the diagnosis of SLE. Further research is needed to explore the potential role of FCRL3 and TIGIT in SLE. [Extracted from the article]

Loewi's discovery of acetylcholine (ACh) release from the frog vagus nerve and the discovery by Dale and Dudley of ACh in ox spleen led to the demonstration of chemical transmission of nerve impulses. ACh is now well-known to function as a neurotransmitter. However, advances in the techniques for ACh detection have led to its discovery in many lifeforms lacking a nervous system, including eubacteria, archaea, fungi, and plants. Notably, mRNAs encoding choline acetyltransferase and muscarinic and nicotinic ACh receptors (nAChRs) have been found in uninnervated mammalian cells, including immune cells, keratinocytes, vascular endothelial cells, cardiac myocytes, respiratory, and digestive epithelial cells. It thus appears that non-neuronal cholinergic systems are expressed in a variety of mammalian cells, and that ACh should now be recognized not only as a neurotransmitter, but also as a local regulator of non-neuronal cholinergic systems. Here, we discuss the role of non-neuronal cholinergic systems, with a focus on immune cells. A current focus of much research on non-neuronal cholinergic systems in immune cells is α7 nAChRs, as these receptors expressed on macrophages and T cells are involved in regulating inflammatory and immune responses. This makes α7 nAChRs an attractive potential therapeutic target. [ABSTRACT FROM AUTHOR]

Background: Regulatory T cells (Tregs) are crucial in maintaining immune homeostasis and preventing autoimmunity and inflammation. A proportion of Treg cells can lose Foxp3 expression and become unstable under inflammation conditions. The precise mechanisms underlying this phenomenon remain unclear. Methods: The PI16 gene knockout mice (PI16fl/flFoxp3Cre) in Treg were constructed, and the genotypes were identified. The proportion and phenotypic differences of immune cells in 8-week-old mice were detected by cell counter and flow cytometry. Two groups of mouse Naïve CD4+T cells were induced to differentiate into iTreg cells to observe the effect of PI16 on the differentiation and proliferation of iTreg cells, CD4+CD25+Treg and CD4+CD25− effector T cells (Teff) were selected and co-cultured with antigen presenting cells (APC) to observe the effect of PI16 on the inhibitory ability of Treg cells in vitro. The effects of directed knockout of PI16 in Treg cells on inflammatory symptoms, histopathological changes and immune cell expression in mice with enteritis and autoimmune arthritis were observed by constructing the model of antigen-induced arthritis (AIA) and colitis induced by dextran sulfate sodium salt (DSS). Results: We identified peptidase inhibitor 16 (PI16) as a negative regulator of Treg cells. Our findings demonstrate that conditional knock-out of PI16 in Tregs significantly enhances their differentiation and suppressive functions. The conditional knockout of the PI16 gene resulted in a significantly higher abundance of Foxp3 expression (35.12 ± 5.71% vs. 20.00 ± 1.61%, p = 0.034) in iTreg cells induced in vitro compared to wild-type mice. Mice with Treg cell-specific PI16 ablation are protected from autoimmune arthritis (AIA) and dextran sulfate sodium (DSS)-induced colitis development. The AIA model of PI16CKO is characterized by the reduction of joint structure and the attenuation of synovial inflammation and in DSS-induced colitis model, conditional knockout of the PI16 reduce intestinal structural damage. Additionally, we found that the deletion of the PI16 gene in Treg can increase the proportion of Treg (1.46 ± 0.14% vs. 0.64 ± 0.07%, p < 0.0001) and decrease the proportion of Th17 (1.00 ± 0.12% vs. 3.84 ± 0.64%, p = 0.001). This change will enhance the shift of Th17/Treg toward Treg cells in AIA arthritis model (0.71 ± 0.06% vs. 8.07 ± 1.98%, p = 0.003). In DSS-induced colitis model of PI16CKO, the proportion of Treg in spleen was significantly increased (1.40 ± 0.15% vs. 0.50 ± 0.11%, p = 0.003), Th17 (2.18 ± 0.55% vs. 6.42 ± 1.47%, p = 0.017), Th1 (3.42 ± 0.19% vs. 6.59 ± 1.28%, p = 0.028) and Th2 (1.52 ± 0.27% vs. 2.76 ± 0.38%, p = 0.018) in spleen was significantly decreased and the Th17/Treg balance swift toward Treg cells (1.44 ± 0.50% vs. 24.09 ± 7.18%, p = 0.012). Conclusion: PI16 plays an essential role in inhibiting Treg cell differentiation and function. Conditional knock out PI16 gene in Treg can promote the Treg/Th17 balance towards Treg dominance, thereby alleviating the condition. Targeting PI16 may facilitate Treg cell-based therapies for preventing autoimmune diseases and inflammatory diseases. The research provides us with novel insights and future research avenues for the treatment of autoimmune diseases, particularly arthritis and colitis. [ABSTRACT FROM AUTHOR]

More than 80% of patients with myasthenia gravis (MG) are positive for anti-acetylcholine receptor (AChR) antibodies. Regulatory T cells (Tregs) suppress overproduction of these antibodies, and patients with AChR antibody-positive MG (AChR MG) exhibit impaired Treg function and reduced Treg numbers. The gut microbiota and their metabolites play a crucial role in maintaining Treg differentiation and function. However, whether impaired Tregs correlate with gut microbiota activity in patients with AChR MG remains unknown. Here, we demonstrate that butyric acid-producing gut bacteria and serum butyric acid level are reduced in patients with AChR MG. Butyrate supplementation effectively enhanced Treg differentiation and their suppressive function of AChR MG. Mechanistically, butyrate activates autophagy of Treg cells by inhibiting the mammalian target of rapamycin. Activation of autophagy increased oxidative phosphorylation and surface expression of cytotoxic T-lymphocyte-associated protein 4 on Treg cells, thereby promoting Treg differentiation and their suppressive function in AChR MG. This observed effect of butyrate was blocked using chloroquine, an autophagy inhibitor, suggesting the vital role of butyrate-activated autophagy in Tregs of patients with AChR MG. We propose that gut bacteria derived butyrate has potential therapeutic efficacy against AChR MG by restoring impaired Tregs. [ABSTRACT FROM AUTHOR]

Forkhead box P3 (Foxp3)-expressing regulatory T (Treg) cells play essential roles in immune homeostasis but also contribute to establish a favorable environment for tumor growth by suppressing anti-tumor immune responses. It is thus necessary to specifically target tumor-infiltrating Treg cells to minimize effects on immune homeostasis in cancer immunotherapy. However, molecular features that distinguish tumor-infiltrating Treg cells from those in secondary lymphoid organs remain unknown. Here we characterize distinct features of tumor-infiltrating Treg cells by global analyses of the transcriptome and chromatin landscape. They exhibited activated phenotypes with enhanced Foxp3-dependent transcriptional regulation, yet being distinct from activated Treg cells in secondary lymphoid organs. Such differences may be attributed to the extensive clonal expansion of tumor-infiltrating Treg cells. Moreover, we found that TCF7 and LEF1 were specifically downregulated in tumor-infiltrating Treg cells both in mice and humans. These factors and Foxp3 co-occupied Treg suppressive function-related gene loci in secondary lymphoid organ Treg cells, whereas the absence of TCF7 and LEF1 accompanied altered gene expression and chromatin status at these gene loci in tumor-infiltrating Treg cells. Functionally, overexpression of TCF7 and LEF1 in Treg cells inhibited the enhancement of Treg suppressive function upon activation. Our results thus show the downregulation of TCF7 and LEF1 as markers of highly suppressive Treg cells in tumors and suggest that their absence controls the augmentation of Treg suppressive function in tumors. These molecules may be potential targets for novel cancer immunotherapy with minimum effects on immune homeostasis. [ABSTRACT FROM AUTHOR]

Sepsis is a serious, potentially fatal disease caused by the body's reaction to microbial invasions by bacteria, viruses, and fungi. Current research shows that the process of fighting sepsis passes through two phases. The first phase is a cytokine storm, and the second phase involves a cycle of pro-inflammatory and anti-inflammatory responses led by Regulatory CD4+ T-cells (CD4+ Tregs). Various immunomodulatory therapies have been proposed to break the cycle of pro- and anti-inflammatory reactions to sepsis. However, clinical trials are yet to show any promising results, indicating the need for further research into the mechanisms behind Treg dysfunction. We used next-generation sequencing (NGS) analysis of five datasets comprising of bulk RNA-seq and single-cell RNA-seq data to explore our research question. Our results identified Acod1 (Aconitate Decarboxylase 1) as a primary mediator of Treg suppression of immune cells as well as various metabolic pathways regulated by IL4 and IL10. scRNA-seq analysis showed that Acod1 and FoxP3 were localised in the same Treg-like cells. Further evidence from our study further suggests a mutual positive regulation loop between Acod1 and FoxP3 in sepsis. Additionally, CD36 was identified as a downstream target of Acod1. CD36 is a known metabolite regulator in Tregs, where it functions as a transporter of long fatty chains (LCFA) and is regulated by IL4 and IL10. Taken together, our results indicate that the metabolic CD36/Acod1 axis could be responsible for the continuous activation of Treg in sepsis. Thus, targeting this axis could prove valuable in improving the sepsis prognosis. [ABSTRACT FROM AUTHOR]

Myocardial infarction (MI) induces the generation of proinflammatory Ly6Chigh monocytes in the spleen and the recruitment of these cells to the myocardium. CD4+ Foxp3+ CD25+ T-cells (Tregs) promote the healing process after myocardial infarction by engendering a pro-healing differentiation state in myocardial monocyte-derived macrophages. We aimed to study the effects of CD4+ T-cells on splenic myelopoiesis and monocyte differentiation. We instigated MI in mice and found that MI-induced splenic myelopoiesis is abrogated in CD4+ T-cell deficient animals. Conventional CD4+ T-cells promoted myelopoiesis in vitro by cell–cell-contact and paracrine mechanisms, including interferon-gamma (IFN-γ) signalling. Depletion of regulatory T-cells enhanced myelopoiesis in vivo, as evidenced by increases in progenitor cell numbers and proliferative activity in the spleen 5 days after MI. The frequency of CD4+ T-cells-producing factors that promote myelopoiesis increased within the spleen of Treg-depleted mice. Moreover, depletion of Tregs caused a proinflammatory bias in splenic Ly6Chigh monocytes, which showed predominantly upregulated expression of IFN-γ responsive genes after MI. Our results indicate that conventional CD4+ T-cells promote and Tregs attenuate splenic myelopoiesis and proinflammatory differentiation of monocytes. [ABSTRACT FROM AUTHOR]

Numerous studies have demonstrated that regulatory T (Treg) cells play an important role in the tumour microenvironment (TME). The aim of this study was to investigate whether VEGFR2 affects the expression of miR-3200-3p in exosomes secreted by tumour cells, thereby influencing Treg senescence in the TME. The results showed that VEGFR2 expression level was the highest in Calu-1 cells, and after transfection with si-VEGFR2, the exosomes secreted from Calu-1 cells were extracted and characterised with no significant difference from the exosomes of the untransfected group, but the expression of miR-3200-3p in the exosomes of the transfected si-VEGFR2 group was elevated. The Cell Counting Kit-8 (CCK-8) and flow cytometry (FCM) results suggested that exosomes highly expressing miR-3200-3p could inhibit Treg cell viability and promote apoptosis levels when treated with Treg cells. Detection of the senescence-associated proteins p16 INK4A and MMP3 by western blot (WB) revealed that exosomes highly expressing miR-3200-3p were able to elevate their protein expression levels. Tumour xenograft experiments demonstrated that exosomes with high miR-3200-3p expression promoted Treg cell senescence and inhibited subcutaneous tumour growth in nude mice. Dual-luciferase reporter assays and RNA pull-down assays showed that miR-3200-3p could be linked with DDB1. Overexpression of DDB1 reverses changes in DCAF1/GSTP1/ROS protein expression caused by exosomes with high miR-3200-3p expression. In conclusion, inhibition of VEGFR2 expression in tumour cells promotes the expression of miR-3200-3p in exosomes secreted by tumour cells. miR-3200-3p enters the TME through exosomes and acts on DDB1 in Treg cells to promote senescence of Treg cells to inhibit tumour progression. [ABSTRACT FROM AUTHOR]

The spleen is essential for lymphocyte proliferation, which is associated to sepsis prognosis. Adenosine 2A receptor (A2AR) blocking promotes lymphocyte proliferation in sepsis, however the mechanism is uncertain. Our sepsis cecum ligation perforation model showed that blocking A2AR increased survival and CD4+ cell numbers in a spleen‐dependent mechanism. The sequencing of the transcriptome of the spleen indicated alterations in the expression of genes involved in the control of lymphocyte proliferation by inhibiting A2AR, including a reduction in the expression of PD‐L1. Flow cytometry analysis of PD‐L1 expression intensity in splenic cell subpopulations revealed that the Treg cell subpopulation was the strongest PD‐L1‐expressing cell population, and Treg PD‐L1 expression decreased after blocking A2AR. In vitro activation of A2AR was able to upregulate PD‐L1 expression of Treg and boost Treg capacity to limit lymphocyte proliferation, while blockage of PD‐L1 partly reduced A2AR‐activated Treg's ability to inhibit lymphocyte proliferation. In addition, blocking CREB phosphorylation significantly inhibited A2AR‐induced PD‐L1 expression. According to the findings of our research, inhibiting A2AR improves the prognosis of sepsis by lowering the level of PD‐L1 expression by Treg in the spleen and reducing the inhibition of lymphocyte proliferation. [ABSTRACT FROM AUTHOR]

T cells play critical role in multiple immune processes including antigen response, tumor immunity, inflammation, self-tolerance maintenance and autoimmune diseases et. Fetal liver or bone marrow-derived thymus-seeding progenitors (TSPs) settle in thymus and undergo T cell-lineage commitment, proliferation, T cell receptor (TCR) rearrangement, and thymic selections driven by microenvironment composed of thymic epithelial cells (TEC), dendritic cells (DC), macrophage and B cells, thus generating T cells with diverse TCR repertoire immunocompetent but not self-reactive. Additionally, some selfreactive thymocytes give rise to Treg with the help of TEC and DC, serving for immune tolerance. The sequential proliferation, cell fate decision, and selection during T cell development and self-tolerance establishment are tightly regulated to ensure the proper immune response without autoimmune reaction. There are remarkable progresses in understanding of the regulatory mechanisms regarding ubiquitination in T cell development and the establishment of self-tolerance in the past few years, which holds great potential for further therapeutic interventions in immune-related diseases. [ABSTRACT FROM AUTHOR]

Introduction: Allergen-specific immunotherapy (AIT) plays a pivotal role in altering the immune status and tissue responses in allergic rhinitis (AR). This study focuses on the impact of sublingual immunotherapy (SLIT) involving dust mite drops, exploring the modulation of regulatory T cells (Treg) and their specific marker, BLIMP1, in the nasal mucosa. Methods: Immune cells were isolated from nasal lavage fluid of patients with AR undergoing SLIT (n = 94). Treg cells were analyzed for BLIMP1 expression, and chemokine levels associated with Treg recruitment were assessed using Luminex assay. Patients were categorized on the basis of SLIT efficacy and followed for changes after discontinuation. Results: SLIT induced a significant increase in nasal Treg cells (7.09 ± 2.59% vs. 0.75 ± 0.27%, P < 0.0001). BLIMP1 expression in Treg cells notably increased after SLIT (0.36 ± 0.22% to 16.86 ± 5.74%, P < 0.0001). Ineffective SLIT cases exhibited lower levels of nasal Treg and Blimp1 + Treg cells (both P < 0.0001). Receiver operating characteristic (ROC) analysis confirmed their potential as efficacy predictors (AUC = 0.908 and 0.968, respectively). SLIT discontinuation led to a significant reduction in Treg and Blimp1 + Treg cells (P < 0.001), emphasizing their maintenance during treatment. Pro-inflammatory cytokines decreased (P < 0.001), while CCL2 associated with Treg recruitment increased (P = 0.0015). Conclusion: Elevated nasal Blimp1 + Treg cells serve as a predictive biomarker for SLIT responsiveness in pediatric AR. Their influence on immunotherapy effectiveness contributes to a nuanced understanding of SLIT mechanisms, allowing for disease stratification and personalized treatment plans. This study offers scientific support for predicting SLIT efficacy, enhancing the prospects of improved treatment outcomes in AR. [ABSTRACT FROM AUTHOR]

BackgroundProgressive age-associated change in frequencies and functional capacities of immune cells is known as immunosenescence. Despite data linking chronic environmental, physiological, and psychosocial stressors with accelerated aging, how stress contributes to immunosenesence is not well characterized.ObjectiveTo help delineate the contribution of cumulative physiological stress on immunosensence we assessed relationships between a composite measurement of cumulative physiological stress, reflecting the functioning of the hypothalamic-pituitary-adrenal axis, sympathetic nervous system, cardiovascular system, and metabolic processes, and lymphocyte changes typically affiliated with aging in a cohort of healthy volunteers ranging from 18 to 66 y.ResultsPhysiological stress load positively correlated with subject age in the study cohort and was significantly higher in adults 50-66 y compared to adults 18-33 y and 34-49 y. Using physiological stress load, we identified a significant age-dependent association between stress load and frequencies of circulating regulatory T lymphocytes (Tregs). Frequencies were higher in younger participants, but only in participants exhibiting low physiological stress load. As stress load increased, frequencies of Tregs decreased in young participants but were unchanged with increasing stress load in middle and older age individuals. Follow-up analysis of stress load components indicated lower circulating DHEA-S and higher urinary norepinephrine as the primary contributors to the effects of total stress load on Tregs. In addition, we identified age-independent inverse associations between stress load and frequencies of naïve Tregs and naïve CD4 T cells and positive associations between stress load and frequencies of memory Tregs and memory CD4 T cells. These associations were primarily driven by stress load components waist circumference, systolic and diastolic blood pressure, CRP, and HbA1c. In summary, our study results suggest that, in younger people, physiological stress load may diminish regulatory T cell frequencies to levels seen in older persons. Furthermore, independent of age, stress load may contribute to contraction of the naïve Treg pool and accumulation of memory Treg cells.Clinical trialRegistered on ClincialTrials.gov (Identifier: NCT02367287).

Regulatory T cells (Tregs), a subset of CD4+T cells marked by the expression of the transcription factor forkhead box protein 3 (Foxp3), are pivotal in maintaining immune equilibrium and preventing autoimmunity. In our review, we addressed the functional distinctions between Foxp3+Tregs and other T cells, highlighting their roles in autoimmune diseases and cancer. We uncovered the dual nature of Tregs: they prevented autoimmune diseases by maintaining self-tolerance while contributing to tumor evasion by suppressing anti-tumor immunity. This study underscored the potential for targeted therapeutic strategies, such as enhancing Treg activity to restore balance in autoimmune diseases or depleting Foxp3+Tregs to augment anti-tumor immune responses in cancer. These insights laid the groundwork for future research and clinical applications, emphasizing the critical role of Foxp3+Tregs in immune regulation and the advancement of next-generation immunotherapies.

Bleomycin (BLM) induces lung injury, leading to inflammation and pulmonary fibrosis. Regulatory T cells (Tregs) maintain self-tolerance and control host immune responses. However, little is known about their involvement in the pathology of pulmonary fibrosis. Here we show that a unique Treg subset expressing trefoil factor family 1 (Tff1) emerges in the BLM-injured lung. These Tff1-expressing Tregs (Tff1-Tregs) were induced by IL-33. Moreover, although Tff1 ablation in Tregs did not change the pathological condition, selective ablation of Tff1-Tregs using an intersectional genetic method promoted pro-inflammatory features of macrophages in the injured lung and exacerbated the fibrosis. Taken together, our study revealed the presence of a unique Treg subset expressing Tff1 in BLM-injured lungs and their critical role in the injured lung to ameliorate fibrosis.

Background: The notable decline in the number of Tregs within Necrotizing enterocolitis (NEC) intestinal tissues，contribute to excessive inflammation and necrosis, yet the precise underlying factors remain enigmatic. Ferroptosis, a novel cell death stemming from a disrupted lipid redox metabolism, is the focus of this investigation. Specifically, this study delves into the ferroptosis of Treg cells in the context of NEC and observes the protective effects exerted by vitamin E intervention, which aims to mitigate ferroptosis of Treg cells. Methods: To investigate the reduction of Treg cells in NEC intestine, we analyzed its association with ferroptosis from multiple angles. We constructed a mouse with a specific knockout of Gpx4 in Treg cells, aiming to examine the impact of Treg cell ferroptosis on NEC intestinal injury and localized inflammation. Ultimately, we employed vitamin E treatment to mitigate ferroptosis in NEC intestine's Treg cells, monitoring the subsequent amelioration in intestinal inflammatory damage. Results: The diminution of Treg cells in NEC is attributed to ferroptosis stemming from diminished GPX4 expression. Gpx4-deficient Treg cells exhibit impaired immunosuppressive function and are susceptible to ferroptosis. This ferroptosis of Treg cells exacerbates intestinal damage and inflammatory response in NEC. Notably, Vitamin E can inhibit the ferroptosis of Treg cells, subsequently alleviating intestinal damage and inflammation in NEC. Additionally, Vitamin E bolsters the anti-lipid peroxidation capability of Treg cells by upregulating the expression of GPX4. Conclusion: In the context of NEC, the ferroptosis of Treg cells represents a significant factor contributing to intestinal tissue damage and an exaggerated inflammatory response. GPX4 is pivotal for the viability and functionality of Treg cells. Vitamin E exhibits the capability to mitigate the ferroptosis of Treg cells, thereby enhancing their number and function, which plays a crucial role in mitigating intestinal tissue damage and inflammatory response in NEC.

Regulatory T cells (Tregs) are crucial immune cells that initiate a tolerable immune response. Transforming growth factor-beta (TGFβ) is a key cytokine produced by Tregs and plays a significant role in stimulating tissue fibrosis. Systemic sclerosis, an autoimmune disease characterized by organ fibrosis, is associated with an overrepresentation of regulatory T cells. This review aims to identify Treg-dominant tolerable host immune reactions and discuss their association with scleroderma and end-stage organ failure. End-stage organ failures, including heart failure, liver cirrhosis, uremia, and pulmonary fibrosis, are frequently linked to tissue fibrosis. This suggests that TGFβ-producing Tregs are involved in the pathogenesis of these conditions. However, the exact significance of TGFβ and the mechanisms through which it induces tolerable immune reactions during end-stage organ failure remain unclear. A deeper understanding of these mechanisms could lead to improved preventive and therapeutic strategies for these severe diseases.

Regulatory T cells (Treg) play a prominent role in utero tolerating non-inherited maternal antigens and in regulating immune responses against pathogens at birth. This study investigates Treg immunity in newborns in West Africa, where sepsis remains a major public health problem. Treg phenotypes on neonates subgroups with early-onset sepsis (EOS), presumed sepsis, and healthy newborn with and without prenatal risk factors were evaluated. Treg phenotypes varied according to prenatal conditions, with increase in Treg frequency and Foxp3 expression in healthy newborns with prenatal risk factors compared to those with none risk. Compared to healthy newborns with prenatal risk factors, EOS neonates had a significantly reduced frequency of Treg and Foxp3 expression. In the Treg pool, higher frequency of activated Treg was observed in EOS neonates, suggesting an in-utero activation upstream of the sepsis onset. Their migration to the infection site may explain the reduced frequency of circulating Integrin α4β1+ Treg suggestive of homing to the endothelial tissue. EOS neonates show increases expression of CTLA-4, PD-1 and CD39 on Treg, which negatively regulate the activation of effector T cells (Teff) corroborating by the lower frequency of Teff in EOS neonates. The higher frequency of CD39+ Treg and the lower frequency of integrinα4β1+ Treg in EOS non-survivor suggests that Treg exhaustement and endothelial homing are associated with outcome severity. Neonates developing EOS are born with an altered Treg phenotypic profile. Treg expression of CTLA-4, PD-1, CD39, and integrinα4β1 cell markers can be considered as early warning or diagnostic markers of EOS.

Inflammation is a process that is associated with the activation of distal immunosuppressive pathways that have evolved to restore homeostasis and prevent excessive tissue destruction. However, long-term immunosuppression resulting from systemic and local inflammation that may stem from dysbiosis, infections, or aging poses a higher risk for cancers. Cancer incidence and progression dramatically increase with chronic infections including HIV infection. Thus, studies on pro-tumorigenic effects of microbial stimulants from resident microbiota and infections in the context of inflammation are needed and underway. Here, we discuss chronic infections and potential neuro-immune interactions that could establish immunomodulatory programs permissive for tumor growth and progression.

Introduction & Objectives Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disorder. Dysfunction of regulatory T cells (Treg) may play a role in AD immunopathogenesis.1 Rezpegaldesleukin (REZPEG: NKTR-358) is a polyethylene glycol (PEG)-conjugated recombinant human interleukin 2 (rhIL-2) with the ability to selectively promote the activation and up-to 12-fold expansion of Tregs, while having relatively minimal effect on conventional T cells (Tcons).2 It represents a potential novel therapeutic approach for patients with moderate-to- severe AD. A Phase 1b study of REZPEG for patients with moderate-to-severe AD demonstrated a rapid time to response (2-4 weeks) during induction therapy and a prolonged durability of response, i.e. throughout the 36- week follow-up after cessation of therapy.3 These results support further development of REZPEG for patients with AD. Objective Evaluate the efficacy and safety of REZPEG in patients with moderate-to-severe AD. Materials & Methods This Phase 2b, randomized, double-blinded, placebo-controlled, international, multicenter study of REZPEG vs placebo enrolls biologic and JAK-inhibitor (JAKi) naïve adults with moderate-to-severe AD, defined by a baseline Eczema Area and Severity Index (EASI) score of ≥16, an Investigator's Global Assessment (IGA) AD score of ≥3, affected total body surface area (BSA) of ≥10%, and chronic AD history of at least one year. Patients are randomized in a 3:3:3:2 ratio to three different REZPEG dosing regimens or placebo, administered subcutaneously during the induction phase. Responders achieving EASI50 post-induction are re-randomized to maintenance dosing every 4 or 12 weeks. Non-responders or those experiencing acute exacerbations are transferred to an open-label rescue arm receiving REZPEG. The primary outcome is the least squares mean percentage reduction in EASI from baseline at the end of induction. Secondary and exploratory endpoints include proportions achieving IGA 0/1 with a ≥2 point reduction, EASI75, EASI90, EASI50, itch relief (≥4 point improvement on the Numerical Rating Scale), % BSA improvement, safety, tolerability, patient-reported outcomes (PROs), pharmacokinetics, and pharmacodynamics. Results Trial ongoing (NCT06136741). Conclusion REZPEG represents an innovative approach to stimulate regulatory T cells, potentially offering lasting benefits for patients with moderate-to-severe AD. This Phase 2b trial seeks to define the optimal dosing schedule and further establish the efficacy and safety profile of REZPEG in a population new to biologic and JAK inhibitor therapies. [ABSTRACT FROM AUTHOR]

Introduction & Objectives Alopecia areata (AA) is a chronic inflammatory skin disorder resulting in patchy, non-scaring hair loss. The pathogenesis for AA involves loss of immune privilege for the hair follicle through overactivity of the Th1 and Th17 cells and dysfunction of regulatory T cells (Treg).1 Rezpegaldesleukin (REZPEG: NKTR-358) is a polyethylene glycol (PEG)-conjugated recombinant human interleukin 2 (rhIL-2) with the ability to selectively promote the activation and up-to 12-fold expansion of Tregs, while having relatively minimal effect on conventional T cells (Tcons).2 REZPEG is a biologic therapy and represents a potential novel therapeutic approach for patients with severe to very-severe AA. There are currently no biologic therapies approved for the treatment of AA. REZPEG has previously demonstrated clinical activity in patients with chronic inflammatory skin conditions, including atopic dermatitis (AD), psoriasis, and systemic lupus erythematous. Specifically, a Phase 1b study of REZPEG for patients with moderate-to-severe AD demonstrated a rapid time to response (2-4 weeks) during induction therapy and a prolonged durability of response, i.e. throughout the 36-week follow-up after cessation of therapy. These results support further development of REZPEG for patients with moderate to severe AD (phase 2b study ongoing, NCT06136741) and other inflammatory skin diseases, including AA. Objective Evaluate the efficacy and safety of REZPEG in patients with severe alopecia areata. Materials & Methods We are conducting a Phase 2b, randomized, double-blinded, placebo-controlled, international, multicenter study of REZPEG vs placebo for JAK-inhibitor naïve patients with severe to very severe AA. Eligibility requires adult males (aged 18-60 years) or adult females (aged 18-70) with severe to very severe AA with the following inclusion criteria: baseline Severity Alopecia Tool (SALT) score ≥ 50, stable hair loss for 6-months, current episode of severe AA of less than 8-years, and no hair loss from causes other than AA. Patients will be randomly assigned in a 3:3:2 ratio to 2 different REZPEG dosing regimens vs. placebo, administered subcutaneously, during the treatment period and all patients will undergo an extended follow-up. The primary endpoint for this study is the percent change from baseline in SALT score at end of treatment period. Key secondary/exploratory endpoints include the following: percent change from baseline in SALT score at other assessed timepoints, proportions with ≥ 50%, 75%, 90% reduction in SALT at end of treatment period and other assessed timepoints, proportion of patients with absolute SALT score ≤ 10, ≤ 20, ≤ 30, ≤ 50 at end of treatment period and other assessed timepoints, safety/tolerability, various patient reported outcomes (PROs), pharmacokinetics, and pharmacodynamics. Results Trial ongoing (NCT 06340360). Conclusion REZPEG is a novel regulatory T cell stimulating therapy that may confer prolonged therapeutic benefit for patients with chronic inflammatory skin conditions, including AA and AD. This phase 2b trial is evaluating the efficacy and safety of multiple dosing regimens of REZPEG in JAK-inhibitor and biologic-therapy naïve patients with severe to very severe alopecia areata. [ABSTRACT FROM AUTHOR]

Abstract Background A better understanding of the pathogenesis of polyarticular juvenile idiopathic arthritis (polyJIA) is needed to aide in the development of data-driven approaches to guide selection between therapeutic options. One inflammatory pathway of interest is JAK-STAT signaling. STAT3 is a transcription factor critical to the differentiation of inflammatory T helper 17 cells (Th17s). Previous studies have demonstrated increased STAT3 activation in adult patients with rheumatoid arthritis, but less is known about STAT3 activation in polyJIA. We hypothesized that Th17 cells and STAT3 activation would be increased in treatment-naïve polyJIA patients compared to pediatric controls. Methods Blood from 17 patients with polyJIA was collected at initial diagnosis and again if remission was achieved (post-treatment). Pediatric healthy controls were also collected. Peripheral blood mononuclear cells were isolated and CD4 + T cell subsets and STAT activation (phosphorylation) were evaluated using flow cytometry. Data were analyzed using Mann–Whitney U and Wilcoxon matched-pairs signed rank tests. Results Treatment-naïve polyJIA patients had increased Th17 cells (CD3 + CD4 + interleukin(IL)-17 +) compared to controls (0.15% v 0.44%, p

Despite the success of therapies in lung cancer, more studies of new biomarkers for patient selection are urgently needed. The present study aims to analyze the role of galectin‐3 (GAL‐3) in the lung tumor microenvironment (TME) using tumorspheres as a model and explore its potential role as a predictive and prognostic biomarker in non‐small cell lung cancer patients. For in vitro studies, lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC) primary cultures from early‐stage patients and commercial cell lines were cultured, using tumorsphere‐forming assays and adherent conditions for the control counterparts. We analyzed the pattern of secretion and expression of GAL‐3 using reverse transcription–quantitative real‐time PCR (RTqPCR), immunoblot, immunofluorescence, flow cytometry, and immunoassay analysis. Our results using three‐dimensional (3D) models of lung tumor cells revealed that soluble GAL‐3 (sGAL‐3) is highly expressed and secreted. To more accurately mimic the TME, a co‐culture of tumorspheres and fibroblasts was used, revealing that GAL‐3 could be important as an immunomodulatory molecule expressed and secreted in the TME, modulating immunosuppression through regulatory T cells (TREGS). In the translational phase, we confirmed that patients with high expression levels of GAL‐3 had more TREGS, which suggests that tumors may be recruiting this population through GAL‐3. Next, we evaluated levels of sGAL‐3 before surgery in LUAD and LUSC patients, hypothesizing that sGAL‐3 could be used as an independent prognostic biomarker for overall survival and relapse‐free survival in early‐stage LUAD patients. Additionally, levels of sGAL‐3 at pretreatment and first response assessment from plasma to predict clinical outcomes in advanced LUAD and LUSC patients treated with first‐line pembrolizumab were evaluated, further supporting that sGAL‐3 has a high efficiency in predicting durable clinical response to pembrolizumab with an area under curve of 0.801 (P = 0.011). Moreover, high levels might predict decreased progression‐free survival and OS to anti‐PD‐1 therapy, with sGAL‐3 being a prognosis‐independent biomarker for advanced LUAD.