B cell-targeted therapies in systemic lupus erythematosus

Dysregulated CXCL12 expression in osteoblasts promotes B-lymphocytes preferentially homing to the bone marrow in MRL/lpr mice

Objective: Todetect the abnormal distribution of B-lymphocytes between peripheral and bone marrow (BM) compartments and explore the mechanism of abnormal chemotaxis of B-lymphocytes in lupus subjects. Methods: The proportions of CXC chemokine receptor (CXCR)4+ B cells and CFDA-labeled MRL/lpr-derived B cells were detected by flow cytometry. The levels of CXC chemokine ligand (CXCL)12in peripheral blood (PB)were measured by ELISA. The migrated B cells to osteoblasts (OBs) was measured by transwell migration assay. The relative spatial position of B cells, OBs and CXCL12 was presented by Immunofluorescence assay. Results: Firstly, we found that the percentage of CXCR4+ B cells was lower in PB and higher in the BM from both MRL/lpr mice and patientswith Systemic lupus erythematosus (SLE). Secondly, OBs from MRL/lpr mice produced more CXCL12 than that from C57BL/6 mice. Besides, MRL/lpr-derived OBs demonstrated more potent chemotactic ability toward B-lymphocytes than control OBs by vitro an vivo. Additionally, more B-lymphocytes were found to co-localize with OBs within the periosteal zone of bone in MRL/lpr mice. Lastly, the percentages of CXCR4+B cells were found to be negatively correlated with serum Immunoglobulin (Ig) G concentration, moreover, BM CXCL12 levels were found to be positively correlated with SLE disease activity index Score and negatively correlated with serum Complement3 (C3) concentration. Conclusions: our results indicated that there is a shifted distribution of B-lymphocytes between BM and peripheral compartments in both SLE patients and MRL/lpr mice. Besides, the up-regulated levels of CXCL12 in OBs was indicated to contribute to the enhanced chemotactic migration and anchorage of B-lymphocytes to OBs.

Inhibition of GRK2 ameliorates the pristane-induced mouse SLE model by suppressing plasma cells differentiation

Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disorder characterized by diverse clinical manifestations and organ damage. Despite its elusive etiology, dysregulated subsets and functions of B cells are pivotal in SLE pathogenesis. Peoniflorin-6'-O-benzene sulfonate (CP-25), an esterification modification of Paeoniflorin, exhibits potent anti-inflammatory and immunomodulatory properties in autoimmune diseases (AID). However, the involvement of CP-25 and its target, GRK2, in SLE development has not been explored. In this study, we demonstrate that both genetic deficiency and pharmacological inhibition of GRK2 attenuate autoantibodies production, reduce systemic inflammation, and mitigate histopathological alterations in the spleen and kidney in the pristane-induced mouse SLE model. Importantly, our findings highlight that both genetic deficiency and pharmacological inhibition of GRK2 suppress plasma cells generation and restore dysregulated B-cell subsets by modulating two crucial transcription factors, Blimp1 and IRF4. Collectively, targeting GRK2 with CP-25 emerges as a promising therapeutic approach for SLE.

CAR T cell therapy for refractory pediatric systemic lupus erythematosus: a new era of hope?

Systemic lupus erythematosus (SLE) is a chronic autoimmune condition that can affect multiple organ systems and is heterogenous in its presentation and response to therapy. When diagnosed in childhood, SLE is associated with increased morbidity and mortality compared to adult SLE, often requiring substantial immunosuppression with the risk of significant side effects. There remains a significant unmet need for new therapies that can improve disease control and reduce glucocorticoid and other toxic medication exposure for patients with severe or refractory disease. The pathogenesis of SLE involves B cell dysregulation and autoantibody production, which are a hallmark of the disease. Currently approved B cell directed therapies often result in incomplete B cell depletion and may not target long-lived plasma cells responsible for SLE autoantibodies. It is hypothesized that by persistently eliminating both B cells and plasmablasts, CAR T therapy can halt autoimmunity and prevent organ damage in patient's refractory to current B cell-depleting treatments. Herein we summarize the current preclinical and clinical data utilizing CAR T cells for SLE and discuss the future of this treatment modality for lupus.

Global research trends in precision-targeted therapies for systemic lupus erythematosus (2003-2023): A bibliographic study

Background

Systemic lupus erythematosus (SLE) is a persistent inflammatory disease caused by an autoimmune response that predominantly affects multiple organs and systems. Growing evidence highlights the critical role of precision-targeted therapies in the management of SLE. Surprisingly, only a handful of bibliometric studies have thoroughly assessed this area. This study attempts to assess the global landscape of literature output and research trends related to precision-targeted therapy for SLE.

Method

Publications related to precision-targeted therapy for SLE from 2003 to 2023 were searched in the Web of Science Core Collection (WoSCC) database. VOSviewers, CiteSpace and the R package "bibliometrix" were used to perform this bibliometric analysis.

Results

A total of 3700 papers were retrieved, showing a steady annual increase in publications from 2003 to 2022. The United States led the field with the highest number of papers (36.1 %) and secured the top position in terms of citation frequency (59,889) and H-index (115). Anhui Medical University System claimed the top spot with an impressive output of 70 papers. Principal investigators Tsokos, George C. C., and Lu, Qianjin led the research effort. Among the journals, Frontiers in Immunology stood out, publishing the highest number of articles with 191. In particular, precision-targeted therapy for SLE has become a major research focus in recent years, covering aspects such as T cells, B cells, oxidative stress, remission, and PHASE-III.

Conclusion

This bibliometric study of ours systematically analyses research trends in precision targeted therapy for systemic lupus erythematosus, and this information identifies the research frontiers and hot directions in recent years and will serve as a reference for scientists working on targeted therapies.

Advances in Systemic Lupus Erythematosus Treatment With Monoclonal Antibodies: A Mini-Review

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organs and systems. It is characterized by the production of abnormal antibodies that attack healthy cells and tissues. The disease presents a wide range of symptoms and severity, from mild to severe. Diagnosis can be complex, but the classification criteria of the American College of Rheumatology (ACR) help to facilitate it. Incidence and prevalence vary considerably worldwide, mainly affecting adult women between the third and fourth decades of life, although it can also occur in childhood. The prognosis of SLE has improved over time, but there is still a risk of irreversible organ damage. Treatment is individualized for each patient and is based on immunosuppression and the use of corticosteroids. Biological therapies, such as monoclonal antibodies, have emerged as a more specific alternative. Methotrexate, antimalarials, glucocorticoids, immunosuppressants, and monoclonal antibodies are some of the medications used to treat SLE. New therapeutic strategies are currently being developed, such as targeted therapies, immunomodulators, and biological agents. Treatment adherence, monitoring, and regular follow-up are important aspects of SLE management. This article aims to describe the characteristics of the new monoclonal antibody therapies that exist for the management of SLE.

Dihydroartemisinin inhibits follicular helper T and B cells: implications for systemic lupus erythematosus treatment

Systemic lupus erythematosus (SLE) is a common autoimmune disease, and its pathogenesis mainly involves the aberrant activation of B cells through follicular helper T (Tfh) cells to produce pathogenic antibodies, which requires more effective and safe treatment methods. Dihydroartemisinin (DHA) is the main active ingredient of artemisinin and has immunosuppressive effects. In this study, in vitro experiments confirmed that DHA inhibited Tfh cell induction and weakened its auxiliary function in B cell differentiation; furthermore, DHA directly inhibited B cell activation, differentiation, and antibody production. Furthermore, a mouse model of SLE was established, and we confirmed that DHA significantly reduced the symptoms of SLE and lupus nephritis, and decreased serum immunoglobulin (Ig)G, IgM, IgA, and anti-dsDNA levels. Moreover, DHA reduced the frequencies of total Tfh cells, activated Tfh cells, and B cell lymphoma 6, and interleukin (IL)-21 levels in Tfh cells from the spleen and lymph nodes, as well as the levels of B cells, germinal center B cells, and plasma cells in the spleen, lymph nodes, and kidneys. Additionally, DHA inhibited Tfh cells by blocking IL-2-inducible T cell kinase (ITK) signaling and its downstream nuclear factor (NF)-κB, nuclear factor of activated T cell, and activating protein-1 pathways, and directly inhibited B cells by blocking Bruton's tyrosine kinase (BTK) signaling and the downstream NF-κB and Myc pathways. Overall, our results demonstrated that DHA inhibited Tfh cells by blocking ITK signaling and also directly inhibited B cells by blocking BTK signaling. Therefore, reducing the production of pathogenic antibodies might effectively treat SLE.

Inhibition of receptor interacting protein kinase-1 (RIPK1) in the treatment of murine lupus

OBJECTIVE

Systemic lupus erythematosus (SLE) is a type of autoimmune disease that involves multiple organs involved as well as cytokine dysregulation. The treatment of SLE is still challenging due to the side effects of the different drugs used. Receptor-interacting protein kinase 1 (RIPK1) is a kinase involved in T cell homeostasis and autoinflammation. Although clinical trials have shown that RIPK1 inhibition exhibits significant efficacy in different autoimmune diseases, its role in SLE remains unclear.

METHODS

MRL/lpr lupus-prone mice received RIPK1 inhibitor ZJU37 or vehicle intraperitoneally for 10 weeks. A BM12-induced chronic graft-versus-host-disease (cGVHD) lupus-like model was introduced in RIPK1 D138N mice or C57BL/6 mice. Nephritis, serum autoantibody levels, dysregulation of adaptive immune response and cytokines were compared in treated and untreated mice.

RESULTS

ZJU37 alleviated the clinical features of the MRL/lpr mice including nephritis and anti-dsDNA antibody production. In addition, ZJU37 treatment reduced the proportion of double-negative T cells in the spleen and the cytokines of TNFα, IFN-γ, IL-6, IL-17 and IL-1β in the serum. Moreover, RIPK1 D138N mice were able to prevent the cGVHD lupus-like model from SLE attack, manifesting as anti-dsDNA antibody production, the proliferation of germinal centre B cells, plasma cells, and T follicular helper cells as well as IgG and C3 deposits in kidneys.

CONCLUSION

RIPK1 inhibition has a protective effect in the mouse model of SLE and can potentially become a new therapeutic target for SLE in humans.

ETV5 promotes lupus pathogenesis and follicular helper T cell differentiation by inducing osteopontin expression

Follicular helper T (TFH) cells mediate germinal center reactions to generate high affinity antibodies against specific pathogens, and their excessive production is associated with the pathogenesis of systemic autoimmune diseases such as systemic lupus erythematosus (SLE). ETV5, a member of the ETS transcription factor family, promotes TFH cell differentiation in mice. In this study, we examined the role of ETV5 in the pathogenesis of lupus in mice and humans. T cell-specific deletion of Etv5 alleles ameliorated TFH cell differentiation and autoimmune phenotypes in lupus mouse models. Further, we identified SPP1 as an ETV5 target that promotes TFH cell differentiation in both mice and humans. Notably, extracellular osteopontin (OPN) encoded by SPP1 enhances TFH cell differentiation by activating the CD44-AKT signaling pathway. Furthermore, ETV5 and SPP1 levels were increased in CD4+ T cells from patients with SLE and were positively correlated with disease activity. Taken together, our findings demonstrate that ETV5 is a lupus-promoting transcription factor, and secreted OPN promotes TFH cell differentiation.

Cytokine and reactivity profiles in SLE patients following anti-CD19 CART therapy

Chimeric antigen receptor (CAR) T cells targeting CD19+ B cells have demonstrated efficacy in refractory systemic lupus erythematosus (SLE). Although initial clinical data suggest that anti-CD19 CAR T cell therapy is well tolerated and highly effective, the immunologic consequences of CAR T cell therapy in SLE patients remain unclear. We profiled serum in six refractory SLE patients prior to and 3 months following CAR T cell infusion. Three months post T cell infusion, the inflammatory cytokines IL-6 and TNFα decreased in patient sera. This was accompanied by elevations in serum IL-7 and BAFF. Furthermore, SLE-associated antibodies dropped profoundly in five of six patients. Last, consistent with other reports of CD19 CAR T therapy in B cell malignancies, we were able to show marginal impact of anti-CD19 CART therapy on pre-existing humoral immune responses in SLE patients. Together, these results provide insights into the mechanisms of efficacy of anti-CD19 CAR T cell therapy in SLE.

Emerging treatment for Sjögren's disease: a review of recent phase II and III trials

INTRODUCTION

Sjögren's Disease, SjD, is a systemic autoimmune disorder characterized by reduced function of the salivary and lacrimal glands. Patients suffer from dryness, fatigue, and pain and may present with or without extra-glandular organ involvement. Symptoms limit SjD patients' quality of life and are the most difficult to improve with therapy. SjD patients are heterogeneous and clustering them into biologically similar subgroups might improve the efficacy of therapies. The need for therapies that address both the symptoms and extra glandular organ involvement of SjD presents an unmet opportunity that has recently attracted a growing interest in the pharmaceutical industry.

AREAS COVERED

The goal of this report is to review recent phase II/III studies in SjD. To accomplish our goal, we performed a literature search for phase II/III studies and abstracts recently presented at conferences.

EXPERT OPINION

This review allows updates the reader on the multitude of recent phase II/III clinical trials. We speculate on how subtypes of SjD will drive future therapeutic targeting and inform pathogenesis.

B cell subsets-related biomarkers and molecular pathways for systemic lupus erythematosus by transcriptomics analyses

BACKGROUND

Systemic lupus erythematosus (SLE), an autoimmune disease, is characterised by B-cell abnormalities and a loss of tolerance that can produce autoantibody. However, the imperative genes and molecular pathways involved in the change of B cell populations remain unclear.

METHODS

The expression of B cell subsets between SLE and healthy controls (HCs) was detected based on micro-array transcriptome data. The Weighted Gene Co-Expression Network Analysis (WGCNA) further revealed the co-expression modules of naïve and memory B cells. Whereafter, we performed the functional enrichment analysis, Protein-protein interaction (PPI) networks construction and feature selection to screen hub genes. Ultimately, we recruited SLE patients and HCs from the Second Hospital of Shanxi Medical University and further verified these genes in transcriptome sequencing samples.

RESULTS

Total of 1087 SLE patients and 86 HCs constituted in the study. Compared to HCs, the levels of peripheral naïve B cells of SLE patients decreased, while memory B cells increased. WGCNA identified two modules with the highest correlation for the subsequent analysis. The purple module was primarily in connection with naïve B cells, and the GO analysis indicated that these genes were mainly abundant in B cell activation. The blue module relevant to memory B cells was most significantly enriched in the "defence response to virus" correlation pathway. Then we screened six hub genes by PPI and feature selection. Finally, four biomarkers (IFI27, IFITM1, MX2, IRF7) were identified by transcriptome sequencing verification.

CONCLUSION

Our study identified hub genes and key pathways associated with the naïve and memory B cells respectively, which may offer novel insights into the behaviours of B cells and the pathogenesis of SLE.

The role of B-cell ferroptosis in the pathogenesis of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the dysregulation of B cell subpopulation and function. Recent studies have suggested a potential role of ferroptosis, an iron-dependent form of regulated cell death, in the pathogenesis of SLE. Here, we demonstrate that B-cell ferroptosis occurs both in lupus patients and MRL/lpr mice. Treatment with liproxstatin-1, a potent ferroptosis inhibitor, could reduce autoantibody production, improve renal damage, and alleviate lupus symptoms in vivo. Furthermore, our results suggest that ferroptosis may regulate B cell differentiation and plasma cell formation, indicating a potential mechanism for its involvement in SLE. Taken together, targeting ferroptosis in B cells may be a promising therapeutic strategy for SLE.

Research progress on the clinical application and mechanism of iguratimod in the treatment of autoimmune diseases and rheumatic diseases

Autoimmune diseases are affected by complex pathophysiology involving multiple cell types, cytokines, antibodies and mimicking factors. Different drugs are used to improve these autoimmune responses, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, antibodies, and small molecule drugs (DMARDs), which are prevalent clinically in the treatment of rheumatoid arthritis (RA), etc. However, low cost-effectiveness, reduced efficacy, adverse effects, and patient non-response are unattractive factors driving the development of new drugs such as iguratimod. As a new disease-modifying antirheumatic drug, iguratimod has pharmacological activities such as regulating autoimmune disorders, inflammatory cytokines, regulating immune cell activation, differentiation and proliferation, improving bone metabolism, and inhibiting fibrosis. In recent years, clinical studies have found that iguratimod is effective in the treatment of RA, SLE, IGG4-RD, Sjogren 's syndrome, ankylosing spondylitis, interstitial lung disease, and other autoimmune diseases and rheumatic diseases. The amount of basic and clinical research on other autoimmune diseases is also increasing. Therefore, this review systematically reviews the latest relevant literature in recent years, reviews the research results in recent years, and summarizes the research progress of iguratimod in the treatment of related diseases. This review highlights the role of iguratimod in the protection of autoimmune and rheumatic bone and related immune diseases. It is believed that iguratimod's unique mode of action and its favorable patient response compared to other DMARDs make it a suitable antirheumatic and bone protective agent in the future.

hUC-MSC transplantation therapy effects on lupus-prone MRL/lpr mice at early disease stages

BACKGROUND

The efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation in treating systemic lupus erythematosus (SLE) has been confirmed by small-scale clinical trials. However, these trials focused on severe or refractory SLE, while few studies focused on mild SLE. Therefore, this study focused on the therapeutic effects of hUC-MSC transplantation in early-stage or mild MRL/lpr lupus model mice.

METHODS

Commercially available hUC-MSCs were transplanted into 8-week-old MRL/lpr mice by tail vein injection. Flow cytometry was used to analyze B cells and their subsets in the peripheral blood. Further, plasma inflammatory factors, autoantibodies, and plasma biochemical indices were detected using protein chip technology and ELISA kits. In addition, pathological staining and immunofluorescence were performed to detect kidney injury in mice.

RESULTS

hUC-MSC transplantation did not affect the mice's body weight, and both middle and high dose hUC-MSC transplantation (MD and HD group) actually reduced spleen weight. hUC-MSC transplantation significantly decreased the proportion of plasmablasts (PB), IgG1- PB, IgG1+ PB, IgG1+ memory B (MB) cells, IgG1+ DN MB, and IgG1+ SP MB cells. The hUC-MSC transplantation had significantly reduced plasma levels of inflammatory factors, such as TNF-α, IFN-γ, IL-6, and IL-13. Pathological staining showed that the infiltration of glomerular inflammatory cells was significantly reduced and that the level of glomerular fibrosis was significantly alleviated in hUC-MSC-transplanted mice. Immunofluorescence assays showed that the deposition of IgG and IgM antibodies in the kidneys of hUC-MSC-transplanted mice was significantly lower than in the control.

CONCLUSION

hUC-MSC transplantation could inhibit the proliferation and differentiation of peripheral blood B cells in the early-stage of MRL/lpr mice, thereby alleviating the plasma inflammatory environment in mice, leading to kidney injury remission. The study provides a new and feasible strategy for SLE treatment.

Current Treatment Approach, Emerging Therapies and New Horizons in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE), the prototype of systemic autoimmune diseases is characterized by extreme heterogeneity with a variable clinical course. Renal involvement may be observed and affects the outcome. Hydroxychloroquine should be administered to every lupus patient irrespective of organ involvement. Conventional immunosuppressive therapy includes corticosteroids, methotrexate, cyclophosphamide, mycophenolate mofetil, azathioprine, cyclosporine and tacrolimus. However, despite conventional immunosuppressive treatment, flares occur and broad immunosuppression is accompanied by multiple side effects. Flare occurrence, target organ involvement, side effects of broad immunosuppression and increased knowledge of the pathogenetic mechanisms involved in SLE pathogenesis as well as the availability of biologic agents has led to the application of biologic agents in SLE management. Biologic agents targeting various pathogenetic paths have been applied. B cell targeting agents have been used successfully. Belimumab, a B cell targeting agent, has been approved for the treatment of SLE. Rituximab, an anti-CD20 targeting agent is also used in SLE. Anifrolumab, an interferon I receptor-targeting agent has beneficial effects on SLE. In conclusion, biologic treatment is applied in SLE and should be further evaluated with the aim of a good treatment response and a significant improvement in quality of life.

A single-cell map of peripheral alterations after FMT treatment in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is characterized by loss of self-tolerance and persistent self-aggression, sustained chronic inflammation, production of autoantibodies and multi-system damage, and is largely incurable to date. The gut microbiota and its metabolites, now recognized as crucial environmental triggers of local/systemic immune reactions, have been implicated in the development and progression of SLE. Fecal microbiota transplantation (FMT) is restoration of disturbed microbiota by transplanting foreign gut microbiota from healthy individuals into the gastrointestinal tract of diseased individuals. Our previous clinical trial suggests that FMT is a potentially safe and effective treatment for SLE. In order to elucidate the potential effect of FMT on peripheral immune cells of patients with SLE, we collected PBMCs (n = 30) of 13 SLE patients who participated in the clinical trial before and after the FMT-treatment, and performed single-cell RNA sequencing. The results first revealed that peripheral T lymphocytes of SLE patients decreased and NK cells increased after the FMT treatment. Then, sub-clustering analysis discovered that total CD4⁺ T cells highly expressed genes of IL7R, CD28, and CD8⁺ T cells highly expressed genes of GZMH and NKG7 after FMT treatment. Moreover, FMT treatment reduced the expression of interferon-related genes (IRGs) in CD4⁺ T, CD8⁺ T, DP, NK, and B cells of SLE patients. More importantly, interferon-related pathways were more enriched in cells of the FMT non-responder group, and further the interferon genes expression of lymphocytes and myeloid cells was negatively correlated with the efficiency of FMT treatment. Collectively, our data identified various immunophenotypic and associated gene set changes following FMT treatment, illustrating the heterogeneity of response to FMT treatment in SLE.

Semaphorin 4A as a Potential Biomarker for Diagnosis of Systemic Lupus Erythematosus

BACKGROUND

Semaphorin 4A (Sema4A) is an immunoregulatory molecule that is closely related to the pathogenesis of some autoimmune diseases. However, the relationship between Sema4A and systemic lupus erythematosus (SLE) remains unknown. We therefore aimed to investigate the expression and clinical value of Sema4A in SLE patients.

METHODS

Patients with SLE, rheumatoid arthritis (RA), and healthy controls (HC) were enrolled. The whole blood samples were collected from SLE (83), RA (29) and HC (85), and the expression of Sema4A on several types of leukocytes in peripheral blood was detected by flow cytometry. The serum samples were collected from SLE(77), RA (23) and HC (63), and the concentrations of soluble Sema4A in plasma were detected by ELISA. The diagnostic value of membrane-bound and soluble Sema4A in SLE patients was evaluated using a receiver operating characteristic (ROC) curve.

RESULTS

The concentration of soluble Sema4A was significantly higher in plasma from SLE patients compared to that from HC and RA patients. In SLE patients, the ratio of CD4+CD11c+ myeloid dendritic cells (mDCs) expressing Sema4A increased significantly, and the levels of soluble Sema4A and membrane-bound Sema4A were negatively correlated with the levels of C3 and C4, respectively. The same result was observed for membrane-bound Sema4A on CD4+CD11c+ mDCs cells. In addition, the level of soluble Sema4A negatively correlated with the concentration of hemoglobin (Hb). Importantly, the expression ratio of membrane-bound Sema4A on CD4+CD11c+ mDCs was positively correlated with systemic lupus erythematosus disease activity index (SLEDAI). Finally, we revealed that soluble and membrane- bound Sema4A had high sensitivity and specificity for diagnosis of SLE, and had a greater ability to distinguish between SLE and RA.

CONCLUSION

Sema4A has potential as a new diagnostic biomarker for SLE, and is promising for distinguishing between SLE and RA.