Activated autophagy restored the impaired frequency and function of regulatory T cells in chronic prostatitis

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

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

Metabolomics Analysis Reveals the Differential Metabolites and Establishes the Therapeutic Effect Prediction Nomogram Among CP/CPPS Patients Who Respond or Do Not Respond to LiST

Objective

Low-intensity shockwave therapy (LiST) has been applied in the clinical treatment of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), but few studies have focused on the prediction of its therapeutic effect before treatment.

Methods

Seventy-five CP/CPPS patients from our institute between July 2020 and May 2021 were enrolled and received 3 Hz, 0.25 mJ/mm² LiST once a week over the course of four weeks. The scores of the NIH-CPSI, IPSS questionnaire and demographic features before treatment were recorded. The plasma before LiST treatment was also collected, while liquid chromatography-tandem mass spectrometry was used to detect the metabolites. Least absolute shrinkage and selection operator (LASSO) regression analysis was employed to identify the prediction metabolites and generate the metabolism score. Receiver operating characteristic curves and calibration curves were drawn to assess the prediction accuracy of the nomogram.

Results

Twelve metabolites were identified at incomparable levels before and after LiST treatment. The metabolism score generated by LASSO analysis presented a perfect prediction value (AUC: 0.848, 95% CI: 0.719-0.940) in the training cohort and further increased to 0.892 (95% CI: 0.802-0.983) on the nomogram, which accompanied with the NIH-CPSI scores and age. Similar results of the metabolism score (AUC: 0.732, 95% CI: 0.516-0.889) and total nomogram (AUC: 0.968, 95% CI: 0.909-1.000) were obtained in the testing cohort. Further enrichment of the 12 metabolites indicated that the glycine and serine metabolism pathway was involved in the LiST treatment.

Conclusion

We used our system to accurately and quantitatively measure plasma metabolites and establish a predictive model to identify suitable patients for LiST treatment.

Gut Microflora Modulates Th17/Treg Cell Differentiation in Experimental Autoimmune Prostatitis via the Short-Chain Fatty Acid Propionate

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a very common urological disorder and has been gradually regarded as an immune-mediated disease. Multiple studies have indicated that the gut microflora plays a pivotal part in immune homeostasis and autoimmune disorder development. However, whether the gut microflora affects the CP/CPPS, and the underlying mechanism behind them remain unclear. Here, we built an experimental autoimmune prostatitis (EAP) mouse model by subcutaneous immunity and identified that its Th17/Treg frequency was imbalanced. Using fecal 16s rRNA sequencing and untargeted/targeted metabolomics, we discovered that the diversity and relative abundance of gut microflora and their metabolites were obviously different between the control and the EAP group. Propionic acid, a kind of short-chain fatty acid (SCFA), was decreased in EAP mice compared to that in controls, and supplementation with propionic acid reduced susceptibility to EAP and corrected the imbalance of Th17/Treg cell differentiation in vivo and in vitro. Furthermore, SCFA receptor G-protein-coupled receptor 43 and intracellular histone deacetylase 6 regulated by propionic acid in Th17 and Treg cells were also evaluated. Lastly, we observed that fecal transplantation from EAP mice induced the decrease of Treg cell frequency in recipient mice. Our data showed that gut dysbiosis contributed to a Th17/Treg differentiation imbalance in EAP via the decrease of metabolite propionic acid and provided valuable immunological groundwork for further intervention in immunologic derangement of CP/CPPS by targeting propionic acid.

Chronic Prostatitis and Pelvic Pain Syndrome: Another Autoimmune Disease?

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), characterized by chronic pain in the perineum or lower abdomen regions, is a frequent disorder in men. Previous studies demonstrated that the immune mediators, including interleukin (IL)-1β, IL-6, interferon-γ, tumor necrosis factor-α, and immunoglobulins, are elevated in the expressed prostate secretions and seminal fluid of CP/CPPS men. The memory T, T helper 1 (Th1), Th17, and Th22 cells increase in the peripheral blood of CP/CPPS men. Additionally, prostate antigens specific-autoreactive T cells are identified in CP/CPPS patients. After generally reviewing and comparing the inflammatory responses in autoimmune diseases and CP/CPPS, we presumed that CP/CPPS is more likely to be defined as an autoimmune disease. Thus, a better understanding of autoimmune diseases would contribute to a deeper understanding of the CP/CPPS and provide new inspirations for the treatment of this disease.

The lncRNA PVT1 regulates autophagy in regulatory T cells to suppress heart transplant rejection in mice by targeting miR-146a

Regulatory T cells (Tregs) are indispensable for the maintenance of immune tolerance. The purpose of this study was to investigate the effect of the interaction of the lncRNA PVT1 and miR-146a on Treg autophagy and reveal the mechanism to alleviate transplant rejection. PVT1 and miR-146a expression levels were analyzed by qRT-PCR. Bioinformatic analysis and methylation profiling were used to determine the relationship between PVT1 and miR-146a. Altered autophagic status in Tregs was detected by western blotting. The effect of autophagy on Treg function was assessed in cell coculture in vitro and in animal models. Our results showed that PVT1 expression was reduced in Tregs during rejection and negatively correlated with miR-146a expression. Higher PVT1 expression was associated with higher autophagy in Tregs. Further, highly autophagic Tregs had stronger inhibitory effects on CD4⁺ T cells in vitro, prolonged allograft survival and alleviated rejection in vivo. Mechanistic studies showed that overexpression of PVT1 enhanced TNF receptor-associated factor (TRAF) 6 expression by directly targeting miR-146a. MiR-146a overexpression reversed PVT1-induced Treg autophagy and inhibited PVT1-induced TRAF6 expression. The present study shows a novel regulatory pathway of the autophagy program that comprises PVT1, miR-146a, and TRAF6. Our findings may provide potential targets and new therapeutic strategies for transplant rejection.

Knockdown of miR-146a in regulatory T cells suppresses heart transplantation rejection in mice by increasing autophagy

Clinical trials of regulatory T cells (Tregs) have shown that adoptive transfer of Tregs has great promise for the treatment of rejection. However, strategies to improve Treg function are needed in order to enhance their efficacy and reduce the number of Tregs required for adoptive transfer. Autophagy is a process for degrading intracellular components, and it mediates cell death, lymphocyte homeostasis, and Treg function. Studies have shown that the survival and function of Tregs with disrupted autophagy are defective. We found that the autophagic status of Tregs was compromised during acute rejection, allowing us to enhance Treg autophagy by regulating microRNA-146a (miR-146a), which is highly expressed in Tregs and is implicated in their function and metabolism. MiR-146a antagomir-mediated miR-146a knockdown promoted Treg autophagy, as evaluated by Western blot analysis. Further, we evaluated whether altering autophagy affects Treg function in both an in vitro cell coculture model and a heart transplantation model in mice. An increase in autophagy enhanced the inhibitory effects of Tregs on CD4⁺ T cells and dendritic cells (DCs) in vivo and in vitro. In addition, adoptive transfer of highly autophagic Tregs treated with miR-146a antagomir significantly alleviated rejection. Collectively, these data provide a new method that uses miR-146a knockdown to increase Treg efficacy by increasing autophagy.