Dysregulation and chronicity of pathogenic T cell responses in the pre-diseased stage of lupus

Exploiting regulatory T cells (Tregs): Cutting-edge therapy for autoimmune diseases

Regulatory T cells (Tregs) are a specialized subset of suppressive T cells that are essential for maintaining self-tolerance, regulating effector T cells, managing microbial infections, preventing tumors, allergies, and autoimmune disorders, and facilitating allograft transplantation. Disruptions in Treg function or abundance contribute to an imbalance between pathogenic and protective immune cells in autoimmune diseases. Recently, one promising treatment strategy to restore immune balance involves the selective expansion or manipulation of Tregs using low-dose IL-2 therapy, adoptive Treg cell transfer, and chimeric antigen receptor (CAR)-Treg approaches. Tregs have been shown in an increasing number of research studies to prevent or even treat a variety of disorders, such as tumors, autoimmune and allergic diseases, transplant rejection, and graft-versus-host disease. A thorough comprehension of Treg function is anticipated to provide clear prospects for effective Treg immunotherapy in the treatment of a wide range of diseases. This review provides an overview of Tregs biology, including their functions, suppressive mechanisms, phenotypic markers, as well as their involvement in disease settings. Furthermore, we discuss the therapeutic potential of different Treg subpopulations and their translational applications in the treatment of autoimmune diseases.

Epigenetic attenuation of interferon signaling drives aging-related improvements in systemic lupus

In the general human population, aging is associated with a rise in systemic inflammation, primarily involving innate immune pathways related to interferon (IFN), toll-like receptor, and cytokine signaling. In systemic lupus erythematosus (SLE), a prototypical systemic autoimmune disease, aging is distinctly associated with improvements in disease activity, suggesting a unique relationship between aging and inflammation in this disease. Using a multi-omic approach incorporating transcriptional profiling, single cell RNA sequencing, proteomics and methylation analysis, we studied age-related changes in the immune profiles of 287 SLE patients between 20 and 83 years old, and compared the results against 928 healthy controls aged between 21 and 89 years old. In contrast to the increase in inflammatory gene expression that occurs with aging in most healthy adults, SLE patients exhibited the opposite. Most notable was a decrease in type I IFN signaling that was evident across multiple cell types, with CD56-dim natural killer (NK) cells, CD4 + effector memory T cells, and naïve B cells exhibiting the most significant differences. We found that aging in SLE patients was also associated with decreased IFN-α2 and IFN-λ1 levels, and differential methylation of the genome. Notably, of the genes both downregulated and hypermethylated with older age, IFN-related genes were disproportionately represented, suggesting that age-related decreases in IFN signaling were driven in part by epigenetic silencing. Both SLE patients and healthy controls demonstrated age-related declines in naïve T cells and lymphoid progenitor cells, but only SLE patients demonstrated age-related increases in CD56-dim NK cells. Taken together, our work provides new insight into the phenomenon of inflammaging and the unique clinical improvement in disease activity that occurs in SLE patients as they age.

Graft survival and mortality outcomes after kidney transplant in patients with lupus nephritis: a systematic review and meta-analysis

To explore the effect of lupus nephritis (LN) on graft survival in renal transplant patients. Literature search was conducted in PubMed, EMBASE and Scopus database for randomized controlled trials (RCTs), cohort, and case-control studies. The target population of interest was adult patients (aged >18 years) with end-stage renal disease (ESRD) and no history of previous renal transplants. Primary outcomes of interest were graft survival and patient survival. Pooled effect estimates were calculated using random-effects models and reported as hazard ratio (HR) with 95% confidence intervals (CI). A total of 15 studies were included. Compared to patients with ESRD due to other causes, patients with LN undergoing kidney transplant had lower patient survival rate (HR 1.15, 95% CI: 1.01, 1.31; N = 15, I2=34.3%) and worse graft survival (HR 1.06, 95% CI: 1.01, 1.11; N = 16, I2=0.0%), especially when studies with deceased donor were pooled together. Studies with a larger sample size (>200) showed that LN was strongly associated with lower graft and patient survival rates. Elevated risk of mortality in LN patients was detected in case-control studies, but not RCTs. On the other hand, RCTs, but not case-control studies, showed an increased risk of poor graft survival in LN patients. The findings suggest that the presence of LN might have a negative impact on both the graft survival and the overall patient survival of post-transplant ESRD patients. Further studies that account for factors such as study methodology, donor characteristics, and sample size are needed to reach definitive conclusions. Renal transplant patients with LN should undergo regular follow-up examinations.

Immunometabolic Mechanisms of LANCL2 in CD4+ T Cells and Phagocytes Provide Protection from Systemic Lupus Erythematosus

Lanthionine synthetase C-like 2 (LANCL2) is an immunoregulatory therapeutic target for autoimmune diseases. NIM-1324 is an investigational new drug aimed at addressing the unmet clinical needs of patients with systemic lupus erythematosus (SLE) by targeting the LANCL2 immunometabolic pathway. In R848 and bm12 adoptive transfer models of systemic inflammation that share pathologies with SLE, Lancl2-/- mice experienced greater mortality, increased spleen weight, and reduced CD25hi FOXP3+ CD4+ regulatory T cells compared with the wild type. Conversely, treatment with NIM-1324 in the wild type increased CD25hi FOXP3+ regulatory T cells while reducing inflammatory IL-17+ and IL-21+ CD4+ T cell subsets in the spleen. In traditional mouse models of SLE (NZB/W F1 and MRL/lpr), oral treatment with NIM-1324 protected against weight loss and proteinuria, decreased anti-dsDNA titers, and provided similar changes to the CD4+ T cell compartment in the spleen. The pharmacological activation of LANCL2 by NIM-1324 rescued hypocomplementemia, reduced kidney histopathological scores, and decreased blood IFN response genes and inflammatory cytokines. The loss of LANCL2 in phagocytes impairs phagosome processing, leading to increased uptake of material and inflammatory cytokine production, yet decreased markers of endosomal maturation, phagosome turnover, and lysozyme activity. Treatment with NIM-1324 increases metabolic and lysozyme activity in the phagosome, providing support for increased markers of early phagosome function. This efficacy translated to human PBMCs from patients with SLE, because ex vivo treatment with NIM-1324 resulted in reduced levels of IFN-α, IL-6, and IL-8. Consequently, the activation of LANCL2 effectively modulates CD4+ T cell differentiation and phagocyte activation, supporting immune tolerance in SLE.

Cell Cultures as a Versatile Tool in the Research and Treatment of Autoimmune Connective Tissue Diseases

Cell cultures are an important part of the research and treatment of autoimmune connective tissue diseases. By culturing the various cell types involved in ACTDs, researchers are able to broaden the knowledge about these diseases that, in the near future, may lead to finding cures. Fibroblast cultures and chondrocyte cultures allow scientists to study the behavior, physiology and intracellular interactions of these cells. This helps in understanding the underlying mechanisms of ACTDs, including inflammation, immune dysregulation and tissue damage. Through the analysis of gene expression patterns, surface proteins and cytokine profiles in peripheral blood mononuclear cell cultures and endothelial cell cultures researchers can identify potential biomarkers that can help in diagnosing, monitoring disease activity and predicting patient's response to treatment. Moreover, cell culturing of mesenchymal stem cells and skin modelling in ACTD research and treatment help to evaluate the effects of potential drugs or therapeutics on specific cell types relevant to the disease. Culturing cells in 3D allows us to assess safety, efficacy and the mechanisms of action, thereby aiding in the screening of potential drug candidates and the development of novel therapies. Nowadays, personalized medicine is increasingly mentioned as a future way of dealing with complex diseases such as ACTD. By culturing cells from individual patients and studying patient-specific cells, researchers can gain insights into the unique characteristics of the patient's disease, identify personalized treatment targets, and develop tailored therapeutic strategies for better outcomes. Cell culturing can help in the evaluation of the effects of these therapies on patient-specific cell populations, as well as in predicting overall treatment response. By analyzing changes in response or behavior of patient-derived cells to a treatment, researchers can assess the response effectiveness to specific therapies, thus enabling more informed treatment decisions. This literature review was created as a form of guidance for researchers and clinicians, and it was written with the use of the NCBI database.

The Role of the Spleen and the Place of Splenectomy in Autoimmune Hemolytic Anemia-A Review of Current Knowledge

Autoimmune hemolytic anemia (AIHA) is a rare, very heterogeneous, and sometimes life-threatening acquired hematologic disease characterized by increased red blood cell (RBC) destruction by autoantibodies (autoAbs), either with or without complement involvement. Recent studies have shown that the involvement of T- and B-cell dysregulation and an imbalance of T-helper 2 (Th2) and Th17 phenotypes play major roles in the pathogenesis of AIHA. AIHA can be primary (idiopathic) but is more often secondary, triggered by infections or drug use or as a part of other diseases. As the location of origin of autoAbs and the location of autoAb-mediated RBC clearance, as well as the location of extramedullary hematopoiesis, the spleen is crucially involved in all the steps of AIHA pathobiology. Splenectomy, which was the established second-line therapeutic option in corticosteroid-resistant AIHA patients for decades, has become less common due to increasing knowledge of immunopathogenesis and the introduction of targeted therapy. This article provides a comprehensive overview of current knowledge regarding the place of the spleen in the immunological background of AIHA and the rapidly growing spectrum of novel therapeutic approaches. Furthermore, this review emphasizes the still-existing expediency of laparoscopic splenectomy with appropriate perioperative thromboprophylaxis and the prevention of infection as a safe and reliable therapeutic option in the context of the limited availability of rituximab and other novel therapies.

Allogeneic cord blood regulatory T cells decrease dsDNA antibody and improve albuminuria in systemic lupus erythematosus

Background

Lupus nephritis (LN) constitutes the most severe organ manifestations of systemic lupus erythematosus (SLE), where pathogenic T cells have been identified to play an essential role in 'helping' B cells to make autoantibodies and produce inflammatory cytokines that drive kidney injury in SLE. Regulatory T cells (Tregs), responsible for decreasing inflammation, are defective and decreased in SLE and have been associated with disease progression. We hypothesize that treatment with allogeneic, healthy Tregs derived from umbilical cord blood (UCB) may arrest such an inflammatory process and protect against kidney damage.

Methods

UCB-Tregs function was examined by their ability to suppress CellTrace Violet-labeled SLE peripheral blood mononuclear cells (PBMCs) or healthy donor (HD) conventional T cells (Tcons); and by inhibiting secretion of inflammatory cytokines by SLE PBMCs. Humanized SLE model was established where female Rag2-/-γc-/- mice were transplanted with 3 × 106 human SLE-PBMCs by intravenous injection on day 0, followed by single or multiple injection of UCB-Tregs to understand their impact on disease development. Mice PB was assessed weekly by flow cytometry. Phenotypic analysis of isolated cells from mouse PB, lung, spleen, liver and kidney was performed by flow cytometry. Kidney damage was assessed by quantifying urinary albumin and creatinine secretion. Systemic disease was evaluated by anti-dsDNA IgG Ab analysis as well as immunohistochemistry analysis of organs. Systemic inflammation was determined by measuring cytokine levels.

Results

In vitro, UCB-Tregs are able to suppress HD Tcons and pathogenic SLE-PBMCs to a similar extent. UCB-Tregs decrease secretion of several inflammatory cytokines including IFN-γ, IP-10, TNF-α, IL-6, IL-17A, and sCD40L by SLE PBMCs in a time-dependent manner, with a corresponding increase in secretion of suppressor cytokine, IL-10. In vivo, single or multiple doses of UCB-Tregs led to a decrease in CD8+ T effector cells in different organs and a decrease in circulating inflammatory cytokines. Improvement in skin inflammation and loss of hair; and resolution of CD3+, CD8+, CD20+ and Ki67+ SLE-PBMC infiltration was observed in UCB-Treg recipients with a corresponding decrease in plasma anti-double stranded DNA IgG antibody levels and improved albuminuria.

Conclusions

UCB-Tregs can decrease inflammatory burden in SLE, reduce auto-antibody production and resolve end organ damage especially, improve kidney function. Adoptive therapy with UCB-Tregs should be explored for treatment of lupus nephritis in the clinical setting.

Vaccination in the Era of Immunosuppression

Patients with autoimmune inflammatory rheumatic diseases (AIIRDs) are at increased risk for severe infections. Vaccine responses and safety profiles may differ between AIIRD patients and the general population. While patients with autoimmune inflammatory rheumatic diseases (AIIRDs) often experience diminished humoral responses and reduced vaccine efficacy, factors such as the type of immunosuppressant medications used and the specific vaccine employed contribute to these outcomes. Notably, individuals undergoing B cell depletion therapy tend to have poor vaccine immunogenicity. However, despite these considerations, vaccine responses are generally considered clinically sufficient. Ideally, immunosuppressed AIIRD patients should receive vaccinations at least two weeks before commencing immunosuppressive treatment. However, it is common for many patients to already be on immunosuppressants during the immunization process. Vaccination rarely triggers flares in AIIRDs; if flares occur, they are typically mild. Despite the heightened infection risk, including COVID-19, among AIIRD patients with rheumatoid arthritis, systemic lupus erythematosus, sarcoidosis, and other diseases on immunosuppressants, the vaccination rates remain suboptimal. The future directions of vaccination in the era of immunosuppression will likely involve customized vaccines with enhanced adjuvants and alternative delivery methods. By addressing the unique challenges faced by immunosuppressed individuals, we may improve vaccine efficacy, reduce the risk of infections, and ultimately enhance the health outcomes. Additionally, clinical trials to evaluate the safety and efficacy of temporarily discontinuing immunosuppressants during vaccination in various AIIRDs are crucial.

Core fucosylation and its roles in gastrointestinal glycoimmunology

Glycosylation is a common post-translational modification in eukaryotic cells. It is involved in the production of many biologically active glycoproteins and the regulation of protein structure and function. Core fucosylation plays a vital role in the immune response. Most immune system molecules are core fucosylated glycoproteins such as complements, cluster differentiation antigens, immunoglobulins, cytokines, major histocompatibility complex molecules, adhesion molecules, and immune molecule synthesis-related transcription factors. These core fucosylated glycoproteins play important roles in antigen recognition and clearance, cell adhesion, lymphocyte activation, apoptosis, signal transduction, and endocytosis. Core fucosylation is dominated by fucosyltransferase 8 (Fut8), which catalyzes the addition of α-1,6-fucose to the innermost GlcNAc residue of N-glycans. Fut8 is involved in humoral, cellular, and mucosal immunity. Tumor immunology is associated with aberrant core fucosylation. Here, we summarize the roles and potential modulatory mechanisms of Fut8 in various immune processes of the gastrointestinal system.

Low-dose interleukin-2 therapy: a promising targeted therapeutic approach for systemic lupus erythematosus

PURPOSE OF REVIEW

Low-dose interleukin-2 (IL-2) therapy is increasingly recognized as a promising novel therapeutic concept in inflammatory and autoimmune diseases, in particular in systemic lupus erythematosus (SLE). As IL-2 is indispensable for the growth and survival of regulatory T cells (Treg), deficiency of this regulatory cytokine plays a significant role in immune dysregulation and breach of tolerance in SLE. Recovery of Treg activity by low-dose IL-2 therapy directly interferes with the immune pathology in SLE and thus can be considered a targeted treatment approach with a unique and physiological mode of action.

RECENT FINDINGS

In this review, the pathophysiological rationales behind the concept of low-dose IL-2 therapy in SLE will be explained and major advances in translational research and the clinical development of low-dose IL-2 therapy focusing on the results from two recent, randomized and placebo-controlled phase 2 trials will be highlighted.

SUMMARY

Several clinical studies including two recent randomized trials have proven the very good safety profile of low-dose IL-2 therapy and its capability to selectively recover and expand the Treg population in patients with active SLE. Given the emerging evidence for the clinical potential of low-dose IL-2 therapy in SLE, these studies strongly confirm the pathophysiological concept behind this targeted therapeutic approach in SLE and provide a robust basis for establishing further in-depth and confirmatory clinical trials testing the application of low-dose IL-2 in SLE and other autoimmune diseases.