AIRE-overexpressing BMDCs suppress TFH cells through ICOSL to prevent and attenuate autoimmune diabetes in NOD mice

Total Alkaloids of Sophora alopecuroides Linn. Attenuates Rheumatoid Arthritis Through Regulating Follicular Helper T Cells

Background

Rheumatoid arthritis (RA) is a chronic autoimmune disease with abnormal differentiation of follicular helper T (Tfh) cells, Total alkaloids of Sophora alopecuroides Linn. (Leguminosae) (TASA) have potential effects on collagen-induced arthritis (CIA) mice, while the mechanism needs further elucidation. The purpose of this study is to explore the regulation of TASA on rheumatoid arthritis and related mechanism.

Methods

The proportion of Tfh and B lymphocytes in peripheral blood lymphocytes of RA patients was examined by flow cytometry. We constructed the collagen induced arthritis DBA/1J mice model. Between days 15 and 45 following the first immunization, the mice were treated intraperitoneally with saline, TASA (100, 50, and 25 mg/kg), and dexamethasone (DXM) for 30 days. Molecular biological techniques such as FCM, PCR, ELISA, and Western-blotting were used to examine Tfh cells and associated signal pathways.

Results

Our results indicated that the follicular helper T cells and B lymphocytes in rheumatoid arthritis patients were significantly increased compared with the healthy control. The percentage of Tfh cells are correlated with RA related inflammatory factors. Total alkaloids of Sophora alopecuroides Linn. could significantly attenuate joint swelling. Meanwhile, it reduced the frequencies of spleen Tfh, B lymphocytes and the expression of TLR2, TLR9, p-NF-κBp65, CXCR5, Bcl-6, ICOS of ankle joints in CIA mice.

Conclusion

Total alkaloids of Sophora alopecuroides Linn. may down-regulate the frequency and function of Tfh cells and inhibit GCB cells via TLRs/NF-κB signal pathway to relieve the immune-pathological progression of CIA mice.

Targeting IL-12 family cytokines: A potential strategy for type 1 and type 2 diabetes mellitus

Diabetes is a common metabolic disease characterized by an imbalance in blood glucose levels. The pathogenesis of diabetes involves the essential role of cytokines, particularly the IL-12 family cytokines. These cytokines, which have a similar structure, play multiple roles in regulating the immune response. Recent studies have emphasized the importance of IL-12 family cytokines in the development of both type 1 and type 2 diabetes mellitus. As a result, they hold promise as potential therapeutic targets for the treatment of these conditions. This review focuses on the potential of targeting IL-12 family cytokines for diabetes therapy based on their roles in the pathogenesis of both types of diabetes. We have summarized various therapies that target IL-12 family cytokines, including drug therapy, combination therapy, cell therapy, gene therapy, cytokine engineering therapy, and gut microbiota modulation. By analyzing the advantages and disadvantages of these therapies, we have evaluated their feasibility for clinical application and proposed possible solutions to overcome any challenges. In conclusion, targeting IL-12 family cytokines for diabetes therapy provides updated insights into their potential benefits, such as controlling inflammation, preserving islet β cells, reversing the onset of diabetes, and impeding the development of diabetic complications.

APECED and the place of AIRE in the puzzle of the immune network associated with autoimmunity

In the last 20 years, discoveries about the autoimmune regulator (AIRE) protein and its critical role in immune tolerance have provided fundamental insights into understanding the molecular basis of autoimmunity. This review provides a comprehensive overview of the effect of AIRE on immunological tolerance and the characteristics of autoimmune diseases in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED), which is caused by biallelic AIRE mutations. A better understanding of the immunological mechanisms of AIRE deficiency may enlighten immune tolerance mechanisms and new diagnostic and treatment strategies for autoimmune diseases. Considering that not all clinical features of APECED are present in a given follow-up period, the diagnosis is not easy in a patient at the first visit. Longer follow-up and a multidisciplinary approach are essential for diagnosis. It is challenging to prevent endocrine and other organ damage compared with other diseases associated with multiple autoimmunities, such as FOXP3, LRBA, and CTLA4 deficiencies. Unfortunately, no curative therapy like haematopoietic stem cell transplantation or specific immunomodulation is present that is successful in the treatment.

Effects of Aire on perforin expression in BMDCs via TLR7/8 and its therapeutic effect on type 1 diabetes

AIMS

Type 1 diabetes, as a kind of autoimmune diseases, usually results from the broken-down of self-tolerance. Autoimmune regulator (Aire), as a transcription factor, induces peripheral tolerance by regulating Toll-like receptor (TLR) expression in dendritic cells (DCs). Several studies have recently identified a small population of perforin-expressing DCs, which is an important population of tolerogenic DCs (tolDCs) that restricts autoreactive T cells in vivo through a perforin-mediated mechanism. Thus, the present study explored the specific relationship among Aire, perforin-expressing DCs and immune tolerance, as well as their roles in type 1 diabetes.

METHODS

We conducted studies based on the Aire-overexpressing bone marrow-derived dendritic cell (BMDC) model. And through in vitro and in vivo experiments to observe that Aire-overexpressing BMDCs which express perforin induce immune tolerance and treat type 1 diabetes via TLR7/8.

RESULTS

Aire enhances the expression of perforin in BMDCs after treatment with the TLR7/8 ligand as well as promotes the expression of TLR7/8 and myeloid differentiation primary response gene 88 (MyD88)-dependent pathway molecules. Aire-overexpressing BMDCs mediate apoptosis of allogeneic CD8⁺ T cells via perforin in vitro. Moreover, Aire-overexpressing BMDCs enhance the therapeutic effect of type 1 diabetes in non-obese diabetic (NOD) mice via perforin and induce apoptosis of autoreactive CD8⁺ T cells in vivo.

CONCLUSIONS

These results provide an experimental basis for comprehensively elucidating the role and significance of Aire expression in peripheral DCs, thereby providing new ideas for the treatment of autoimmune diseases by using Aire as a target to induce the production of perforin-expressing DCs.

Thymic and extrathymic Aire-expressing cells in maternal-fetal tolerance

Healthy pregnancy requires maternal immune tolerance to both fetal and placental tissues which contain a range of self- and non-self-antigens. While many of the components and mechanisms of maternal-fetal tolerance have been investigated in detail and previously and thoroughly reviewed (Erlebacher A. Annu Rev Immunol. 2013;31:387-411), the role of autoimmune regulator (Aire), a critical regulator of central tolerance expressed by medullary thymic epithelial cells (mTECs), has been less explored. Aire is known to facilitate the expression of a range of otherwise tissue-specific antigens (TSAs) in mTECs, and here we highlight recent work showing a role for mTEC-mediated thymic selection in maintaining maternal-fetal tolerance. Recently, however, our group and others have identified additional populations of extrathymic Aire-expressing cells (eTACs) in the secondary lymphoid organs. These hematopoietic antigen-presenting cells possess the ability to induce functional inactivation and/or deletion of cognate T cells, and deletion of maternal eTACs during pregnancy increases T-cell activation in the lymph nodes and lymphocytic infiltration of the uterus, leading to pregnancy complications including intrauterine growth restriction (IUGR) and fetal resorption. In this review, we briefly summarize findings related to essential Aire biology, discuss the known roles of Aire-deficiency related to pregnancy complications and infertility, review the newly discovered role for eTACs in the maintenance of maternal-fetal tolerance-as well as recent work defining eTACs at the single-cell level-and postulate potential mechanisms by which eTACs may regulate this process.