Prophylactic administration of fingolimod (FTY720) ameliorated experimental autoimmune myasthenia gravis by reducing the number of dendritic cells, follicular T helper cells and antibody-secreting cells

Sema-3E/PlexinD1 axis modulates dendritic cell phenotypes and functions: Current status and future implications

This comprehensive research review explores the complex interplay between the Sema-3E/PlexinD1 axis and dendritic cells (DCs), highlighting its critical role in immune modulation with implications for clinical application Critical regulators of immune responses Dendritic cells are central to adaptive immunity, and the Sema-3E /PlexinD1 axis emerges as a key modulator affecting their phenotypes and functions Review delineates the impact of this signaling axis on DC maturation, migration, antigen presentation, and cytokine production, unravels its multifaceted role in shaping the immune response. Recognizing the limitations and gaps in current knowledge, the study highlights the need for further studies to condition downstream signaling events and related information experienced by the Sema-3E/PlexinD1 axis emphasizes the clarity of the immune system. The review concludes by identifying opportunities for translation, focusing on therapeutic and diagnostic potential. It highlights the importance of collaborative, interdisciplinary efforts to address the challenges and harness the therapeutic and pathological potential of targeting the Sema-3E/PlexinD1 axis, thus opening the way for transformative advances in immunology and clinical medicine.

Antibody response to SARS-CoV-2 vaccination or infection in a prospective cohort of children with neuroinflammatory diseases

INTRODUCTION

Immune medications affect antibody responses to SARS-CoV-2 vaccination in adults with neuroinflammatory disorders, but little is known about antibody responses in children with neuroinflammation and on immune treatments. Here we measure antibody levels in response to SARS-CoV-2 vaccination in children receiving anti-CD20 monoclonal antibodies, or fingolimod.

METHODS

Children under 18 years of age with pediatric-onset neuroinflammatory disorders who received at least two mRNA vaccines were included. Plasma samples were assayed for SARS-CoV-2 antibodies (spike, spike receptor binding domain-RBD, nucleocapsid) and neutralization antibodies.

RESULTS

Seventeen participants with pediatric onset neuroinflammatory diseases were included: 12 multiple sclerosis, one neuromyelitis optica spectrum disorder, two MOG-associated disease, and two autoimmune encephalitis. Fourteen were on medications (11 on CD20 monoclonal antibodies-mAbs, one on fingolimod, one on steroids, one on intravenous immunoglobulin) and three were untreated. Nine patients also had pre-vaccination samples available. All participants had seropositivity to spike or spike RBD antibodies except for those receiving CD20 mAbs. However, this proportion was higher in children than in an adult MS patient cohort. The most significant contributor to antibody levels was duration of DMT.

CONCLUSION

SARS-CoV-2 antibodies are decreased in children on CD20 monoclonal antibodies than on other treatments. Treatment duration associated with vaccination responses.

T follicular helper cells in autoimmune diseases

T follicular helper (Tfh) cells with the phenotype of mainly expressing surface molecules C-X-C motif chemokine receptor type 5 (CXCR5), inducible co-stimulator (ICOS), secreting cytokine interleukin-21 (IL-21) and requiring the transcription factor B cell lymphoma 6 (BCL-6) have been recently defined as a new subset of CD4⁺ T cells. They exist in germinal centers (GCs) of lymphoid organs and in peripheral blood. With the ability to promote B cell development, GC formation and antibody production, Tfh cells play critical roles in the pathogenesis of many autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS), etc. The aberrant proliferation and function of Tfh cells will cause the pathological process like autoantibody production and tissue injury. In this paper, we review the recent advances in Tfh cell biology and their roles in autoimmune diseases, with a mention of their use as therapeutic targets, which will shed more light on the pathogenesis and treatment of certain autoimmune diseases.

Immune responses to SARS-CoV-2 vaccination in multiple sclerosis: a systematic review/meta-analysis

INTRODUCTION

Responses to SARS-CoV-2 vaccination in patients with MS (pwMS) varies by disease-modifying therapies (DMTs). We perform a meta-analysis and systematic review of immune response to SARS-CoV-2 vaccines in pwMS.

METHODS

Two independent reviewers searched PubMed, Google Scholar, and Embase from January 1, 2019-December 31, 2021, excluding prior SARS-CoV-2 infections. The meta-analysis of observational studies in epidemiology (MOOSE) guidelines were applied. The data were pooled using a fixed-effects model.

RESULTS

Eight-hundred sixty-four healthy controls and 2203 pwMS from 31 studies were included. Antibodies were detected in 93% healthy controls (HCs), and 77% pwMS, with >93% responses in all DMTs (interferon-beta, glatiramer acetate, cladribine, natalizumab, dimethyl fumarate, alemtuzumab, and teriflunomide) except for 72% sphingosine-1-phosphate modulators (S1PM) and 44% anti-CD20 monoclonal antibodies (mAbs). T-cell responses were detected in most anti-CD20 and decreased in S1PM. Higher antibody response was observed in mRNA vaccines (99.7% HCs) versus non-mRNA vaccines (HCs: 72% inactivated virus; pwMS: 86% vector, 59% inactivated virus). A multivariate logistic regression model to predict vaccine response demonstrated that mRNA versus non-mRNA vaccines had a 3.4 odds ratio (OR) for developing immunity in anti-CD20 (p = 0.0052) and 7.9 OR in pwMS on S1PM or CD20 mAbs (p < 0.0001). Antibody testing timing did not affect antibody detection.

CONCLUSION

Antibody responses are decreased in S1PM and anti-CD20; however, cellular responses were positive in most anti-CD20 with decreased T cell responses in S1PM. mRNA vaccines had increased seroconversion rates compared to non-RNA vaccines. Further investigation in how DMTs affect vaccine immunity are needed.

Skeletal Muscle and COVID-19: The Potential Involvement of Bioactive Sphingolipids

SARS-CoV-2 virus infection is the cause of the coronavirus disease 2019 (COVID-19), which is still spreading over the world. The manifestation of this disease can range from mild to severe and can be limited in time (weeks) or persist for months in about 30–50% of patients. COVID-19 is considered a multiple organ dysfunction syndrome and the musculoskeletal system manifestations are beginning to be considered of absolute importance in both COVID-19 patients and in patients recovering from the SARS-CoV-2 infection. Musculoskeletal manifestations of COVID-19 and other coronavirus infections include loss of muscle mass, muscle weakness, fatigue or myalgia, and muscle injury. The molecular mechanisms by which SARS-CoV-2 can cause damage to skeletal muscle (SkM) cells are not yet well understood. Sphingolipids (SLs) represent an important class of eukaryotic lipids with structural functions as well as bioactive molecules able to modulate crucial processes, including inflammation and viral infection. In the last two decades, several reports have highlighted the role of SLs in modulating SkM cell differentiation, regeneration, aging, response to insulin, and contraction. This review summarizes the consequences of SARS-CoV-2 infection on SkM and the potential involvement of SLs in the tissue responses to virus infection. In particular, we highlight the role of sphingosine 1-phosphate signaling in order to aid the prediction of novel targets for preventing and/or treating acute and long-term musculoskeletal manifestations of virus infection in COVID-19.

Molecular Pharmacology and Novel Potential Therapeutic Applications of Fingolimod

Fingolimod is a well-tolerated, highly effective disease-modifying therapy successfully utilized in the management of multiple sclerosis. The active metabolite, fingolimod-phosphate, acts on sphingosine-1-phosphate receptors (S1PRs) to bring about an array of pharmacological effects. While being initially recognized as a novel agent that can profoundly reduce T-cell numbers in circulation and the CNS, thereby suppressing inflammation and MS, there is now rapidly increasing knowledge on its previously unrecognized molecular and potential therapeutic effects in diverse pathological conditions. In addition to exerting inhibitory effects on sphingolipid pathway enzymes, fingolimod also inhibits histone deacetylases, transient receptor potential cation channel subfamily M member 7 (TRMP7), cytosolic phospholipase A2α (cPLA2α), reduces lysophosphatidic acid (LPA) plasma levels, and activates protein phosphatase 2A (PP2A). Furthermore, fingolimod induces apoptosis, autophagy, cell cycle arrest, epigenetic regulations, macrophages M1/M2 shift and enhances BDNF expression. According to recent evidence, fingolimod modulates a range of other molecular pathways deeply rooted in disease initiation or progression. Experimental reports have firmly associated the drug with potentially beneficial therapeutic effects in immunomodulatory diseases, CNS injuries, and diseases including Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, and even cancer. Attractive pharmacological effects, relative safety, favorable pharmacokinetics, and positive experimental data have collectively led to its testing in clinical trials. Based on the recent reports, fingolimod may soon find its way as an adjunct therapy in various disparate pathological conditions. This review summarizes the up-to-date knowledge about molecular pharmacology and potential therapeutic uses of fingolimod.