The Effects of Silymarin and Cyclosporine A on the Proliferation and Cytokine Production of Regulatory T Cells

Inhibition of Cyclophilin A-Metalloproteinase-9 Pathway Alleviates the Development of Neuropathic Pain by Promoting Repair of the Blood-Spinal Cord Barrier

BACKGROUND

Dysfunction of the blood-spinal cord barrier (BSCB) contributes to the occurrence and development of neuropathic pain (NP). Previous studies revealed that the activation of cyclophilin A (CypA)-metalloproteinase-9 (MMP9) signaling pathway can disrupt the integrity of the blood-brain barrier (BBB) and aggravate neuroinflammatory responses. However, the roles of CypA-MMP9 signaling pathway on BSCB in NP have not been studied. This study aimed to investigate the effect of CypA on the structure and function of the BSCB and pain behaviors in mice with NP.

METHODS

We first created the mouse chronic constriction injury (CCI) model, and they were then intraperitoneally injected with the CypA inhibitor cyclosporine A (CsA) or vehicle. Pain behaviors, the structure and function of the BSCB, the involvement of the CypA-MMP9 signaling pathway, microglia activation, and expression levels of proinflammatory factors in mice were examined.

RESULTS

CCI mice presented mechanical allodynia and thermal hyperalgesia, impaired permeability of the BSCB, downregulated tight junction proteins, activated CypA-MMP9 signaling pathway, microglia activation, and upregulated proinflammatory factors, which were significantly alleviated by inhibition of CypA.

CONCLUSIONS

Collectively, the CypA-MMP9 signaling pathway is responsible for CCI-induced NP in mice by impairing the structure and function of the BSCB, and activating microglia and inflammatory responses.

Co-treatment with Fexofenadine and Budesonide Increases FoxP3 Gene Expression in Patients with Allergic Rhinitis

BACKGROUND

T helper type 2 (Th2), Th17, and regulatory T cells (Tregs) play essential roles in the pathogenesis and control of allergic rhinitis (AR). Fexofenadine and budesonide are first-line treatments for AR. This study aimed to investigate the effect of co-treatment with fexofenadine and budesonide on the expression of Th2, Th17, and Treg-specific transcription factors (GATA-binding protein 3 [GATA-3], RAR-related orphan receptor gamma [RORγt], and forkhead box P3 [FoxP3], respectively) in AR patients.

METHODS

In this study, 29 AR patients were co-treated with fexofenadine and budesonide for 1 month. Blood was collected from AR patients before and after 1 month of treatment. The gene expression levels of GATA-3, RORγt, and FoxP3 transcription factors in blood samples were measured. In addition, serum immunoglobulin E (IgE) levels and eosinophil percentages in blood samples were determined.

FINDINGS

The expression level of FoxP3 increased significantly after treatment compared with that before treatment (P < .001). In contrast, GATA-3 and RORγt expression levels did not show any noticeable changes. In addition, the percentage of peripheral blood eosinophils significantly decreased (P < .01). Serum IgE levels decreased compared with those before treatment, but the difference was not statistically significant. Furthermore, the clinical symptoms of the patients improved compared with those before treatment.

CONCLUSION

Our results showed that combined treatment with fexofenadine and budesonide increased the expression level of the FoxP3 gene, decreased the percentage of peripheral blood eosinophils, and improved the clinical symptoms of AR patients. This regimen appears to improve disease symptoms, at least in part by increasing the Treg population and decreasing the eosinophil population.

Regulating the regulatory T cells as cell therapies in autoimmunity and cancer

Regulatory T cells (Tregs), possess a pivotal function in the maintenance of immune homeostasis. The dysregulated activity of Tregs has been associated with the onset of autoimmune diseases and cancer. Hence, Tregs are promising targets for interventions aimed at steering the immune response toward the desired path, either by augmenting the immune system to eliminate infected and cancerous cells or by dampening it to curtail the damage to self-tissues in autoimmune disorders. The activation of Tregs has been observed to have a potent immunosuppressive effect against T cells that respond to self-antigens, thus safeguarding our body against autoimmunity. Therefore, promoting Treg cell stability presents a promising strategy for preventing or managing chronic inflammation that results from various autoimmune diseases. On the other hand, Tregs have been found to be overactivated in several forms of cancer, and their role as immune response regulators with immunosuppressive properties poses a significant impediment to the successful implementation of cancer immunotherapy. However, the targeting of Tregs in a systemic manner may lead to the onset of severe inflammation and autoimmune toxicity. It is imperative to develop more selective methods for targeting the function of Tregs in tumors. In this review, our objective is to elucidate the function of Tregs in tumors and autoimmunity while also delving into numerous therapeutic strategies for reprogramming their function. Our focus is on reprogramming Tregs in a highly activated phenotype driven by the activation of key surface receptors and metabolic reprogramming. Furthermore, we examine Treg-based therapies in autoimmunity, with a specific emphasis on Chimeric Antigen Receptor (CAR)-Treg therapy and T-cell receptor (TCR)-Treg therapy. Finally, we discuss key challenges and the future steps in reprogramming Tregs that could lead to the development of novel and effective cancer immunotherapies.

Changes in immune profile affect disease progression in hepatocellular carcinoma

Objective: Hepatocellular carcinoma (HCC) as a chronic liver condition is largely associated with immune responses. Previous studies have revealed that different subsets of lymphocytes play fundamental roles in controlling or improving the development and outcome of solid tumors like HCC. Hence, this study aimed to investigate whether immune system changes were related to disease development in HCC patients. Methods: Peripheral blood mononuclear cells were isolated from 30 HCC patients and 30 healthy volunteers using Ficoll density centrifugation. The isolated cells were stained with different primary antibodies and percentages of different immune cells were determined by flow cytometry. Results: HCC patients indicated significant reductions in the numbers of CD4⁺ cells, Tbet+IFNγ+cells, and GATA+IL-4+cells in peripheral blood in comparison with healthy individuals (p < 0.05). There was no significant change in IL-17+RORγt+cells between patient and healthy groups. In contrast, Foxp3+CD127^lowcell frequency was significantly higher in patients than healthy subjects (p < 0.0001). The numbers of Th1, Th2, and Th17 cells were significantly lower in HCC patients than healthy control (p < 0.0001), although the reduction in Th2 cell numbers was not statistically significant. On the contrary, Treg percentage showed a significant increase in patients compared to healthy subjects (p < 0.0001). Other data revealed that Th1, Th2, and Th17 cell frequencies were significantly higher in healthy individuals than patients with different TNM stages of HCC, with the exception of Th2 in patients with stage II HCC (p < 0.01-0.05). Treg percentage was significantly increased in patients with different TNM stages (p < 0.0001). Among all CD4⁺ T cells, the frequency of Th2 cell was significantly associated with TNM stages of HCC (p < 0.05). Conclusion: Our data provide further evidence to show that immune changes may participate in determining HCC progression and disease outcome. However, it should be mentioned that more investigations are needed to clarify our results and explain possible impacts of other immune cells on the pathogenesis of HCC.

Buserelin Inhibits the Immunosuppressive Activity of Regulatory T Cells through the Protein Kinase A Signaling in a Central Precocious Puberty Model

Background: Gonadotropin-releasing hormone analogs (GnRHas) are used for treating central precocious puberty (CPP). However, their roles in the regulation of immune cells especially regulatory T cells (Tregs) remains elusive. Therefore, we characterized buserelin-induced phenotypical and functional changes of Tregs.Methods: A rat CPP model was established followed by administration of buserelin acetate. Flow cytometry was used to evaluate the expression of functional molecules in splenic Tregs. The suppressive activity of Tregs was determined by the suppression assay. GnRHR expression in Tregs was assessed by flow cytometry analysis and Immunoblotting. Normal Tregs were then stimulated and treated with buserelin acetate in vitro. After that, Foxp3 expression, Treg proliferation, and cytokine production were analyzed by flow cytometry. Intracellular signaling was evaluated by Immunoblotting, and Treg function was determined by the suppression assay.Results: After in vivo buserelin treatment, the frequency of splenic Tregs was decreased, with the reduction in the expression of Foxp3, IL-10, and TGF-β. The suppressive activity of Tregs was weakened. Buserelin down-regulated Foxp3 expression while promoting the expression of RORγt and IL-17 in Tregs through activating the protein kinase A (PKA) pathway in vitro. The PKA inhibitor H-89 abolished the effect of buserelin and enhanced Treg function.Conclusion: Buserelin impaired the immunosuppressive activity of Tregs through the PKA signal pathway. Buserelin-induced activation of PKA signaling down-regulated Foxp3 expression while promoting RORγt expression in Tregs, and subsequently weakened Treg function. Our study indicates the necessity of monitoring Treg activity in CPP patients to avoid potential autoimmunity or inflammation.

Characterizing the immune responses of those who survived or succumbed to COVID-19: Can immunological signatures predict outcome?

BACKGROUND

Immunodeficiency has pivotal role in the pathogenesis of coronavirus disease 2019 (COVID-19). Several studies have indicated defects in the immune system of COVID-19 patients at different disease stages. Therefore, this study investigated whether alters in immune responses of COVID-19 patients may be considered as predicting factors for disease outcome.

METHODS

The percentages of innate and adoptive immune cells in the recovered and dead patients with COVID-19, and healthy subjects were determined by flow cytometry. The levels of pro- and anti-inflammatory cytokines and other immune factors were also measured by enzyme-linked immunosorbent assay.

RESULTS

At the first day of hospitalization, the frequencies of CD56^dim CD16⁺ NK cells and CD56^bright CD16^dim/- NK cells in patients who died during treatment were significantly increased compared to recovered and healthy individuals (P < 0.0001). The recovered and dead patients had a significant increase in monocyte number in comparison with healthy subjects (P < 0.05). No significant change was observed in Th1 cell numbers between the recovered and dead patients while Th2, Th17 cell, and Treg percentages in death cases were significantly lower than healthy control and those recovered, unlike exhausted CD4 + and CD8 + T cells and activated CD4 + T cells (P < 0.0001-0.05). The activated CD8 + T cell was significantly higher in the recovered patients than healthy individuals (P < 0.0001-0.05). IL-1α, IL-1β, IL-6, and TNF-α levels in patients were significantly increased (P < 0.0001-0.01). However, there were no differences in TNF-α and IL-1β levels between dead and recovered patients. Unlike TGF-β1 level, IL-10 was significantly increased in recovered patients (P < 0.05). Lymphocyte numbers in recovered patients were significantly increased compared to dead patients, unlike ESR value (P < 0.001-0.01). CRP value in recovered patients significantly differed from dead patients (P < 0.001).

CONCLUSION

Changes in frequencies of some immune cells and levels of some immune factors may be considered as predictors of mortality in COVID-19 patients.

Infection of Epstein-Barr Virus is Associated with the Decrease of Helios+FoxP3+Regulatory T Cells in Active Ulcerative Colitis Patients

Background: Loss of immune homeostasis to enteric pathogens is considered to be involved in the pathogenesis of ulcerative colitis (UC), and regulatory T cells (Tregs) are key for this immune homeostasis. Helios exhibits an important effect on regulating the suppressive function of Tregs. Epstein-Barr virus (EBV) is more commonly detected in UC. However, whether there is an association between EBV infection and Helios⁺Tregs and its impact on disease activity of UC remain unclear. We aimed to explore the clinical significance of Helios⁺Tregs and their potential association with EBV infection in UC. Methods: Seventy-six UC patients and 38 controls were consecutively enrolled. Helios⁺FoxP3⁺Tregs were analyzed using flow cytometry and compared among groups. Eight active UC patients treated with 5-aminosalicylic acid were followed up. Correlation analyses were conducted between Helios⁺FoxP3⁺Tregs and disease activity indicators. In addition, EBV viral loads in the mucosal lesion were quantified in active UC by quantitative polymerase chain reaction and were comprehensively analyzed in subgroups of different disease severity, and their associations with Helios⁺FoxP3⁺Tregs were also analyzed. Results: Helios⁺FoxP3⁺Tregs were significantly decreased in active UC and were inversely correlated with serum C-reactive protein and Mayo score. Moreover, we observed the recovery of Helios⁺FoxP3⁺Tregs in followed-up active UC achieving remission after treatment. EBV loads were higher in active UC, and levels of Helios⁺FoxP3⁺Tregs in the EBV-positive subgroup were lower than the EBV-negative subgroup in moderate and severe active patients. Most importantly, we found that Helios⁺FoxP3⁺Tregs were significantly negatively correlated with EBV viral loads. Conclusion: Helios⁺FoxP3⁺Tregs are likely to play a pivotal role in disease activity of UC and may be influenced by EBV infection.

Effects of the programmed cell death 1 (PDCD1) polymorphisms in susceptibility to systemic lupus erythematosus

The failure of immunological tolerance to self-antigens plays a fundamental role in the pathogenesis of systemic lupus erythematosus (SLE). PD-1 is an inhibitory receptor for regulating the immune system and preventing development of autoimmune disorders. This study aimed to determine the role of four single-nucleotide polymorphisms (SNPs) within programmed cell death 1 (PDCD1 or PD-1) gene and haplotypes defined by these SNPs in susceptibility to SLE in the Iranian population. Blood samples were obtained from 253 SLE and 564 healthy subjects. Red blood cells were lysed and genomic DNAs were extracted using salting-out method. Genotype determinations of PD1.1, PD1.3, PD1.5 and PD1.9 SNPs were performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and 12 haplotypes were constructed by PDCD1 SNPs. Our results showed significant differences in PD1.5 genotype frequencies between patient and control groups (p < .001). The frequencies of PD1.5 C/C, C/T and T/T genotypes versus other genotypes in SLE patients significantly differed from healthy subjects (p < .001, p = .001 and p = .002, respectively). Allelic analysis indicated a significant association between the frequency of PD1.5C allele and development of SLE in our population (odds ratio [OR] = 1.91, 95% confidence interval [CI] = 1.51-2.42, p < .001). At the haplotype level, GGCC, GACT and GGCT haplotypes were significantly different between SLE and control groups (OR = 2.14, 95% CI = 1.73-2.66, p < .001; OR = 9.76, 95% CI = 4.47-21.3, p < .001; and OR = 0.32, 95% CI = 0.24-0.42, p < .001, respectively). Based on these findings, PD1.5 SNP and some haplotypes of PDCD1 contribute to SLE risk in the Iranian population.