Cytotoxic profile of CD3+CD20+ T cells in progressive multiple sclerosis

Association Between T2DM, TyG Index, Multiple Sclerosis, and Rheumatoid Arthritis: Insights into Potential Mechanisms

Abundant research indicates that type 2 diabetes mellitus (T2DM) and insulin resistance (IR) have a certain association with autoimmune-related diseases (ARDs). However, the conclusions remain elusive. Therefore, this study aimed to explore whether there are causal associations between T2DM and IR indicator, triglyceride-glucose (TyG) index with ARDs, and evaluate the impact of immune cells. Comprehensive Mendelian randomization (MR) analysis combined with Bayesian colocalization was employed to investigate the relationship between T2DM, TyG index, ARDs, and specific-marker immune cells by extracting summary-level data from various genome-wide association studies (GWASs). Further investigations utilizing single-cell RNA sequencing (scRNA-seq) analysis were performed to explore the potential molecular mechanisms underlying the MR analysis results. Causal associations of T2DM with multiple sclerosis (MS) and rheumatoid arthritis (RA) were detected. Additionally, the TyG index was genetically predicted to be associated with MS. Furthermore, immune cells were found to be related to T2DM and TyG index, of which CD3 on naive CD8 + T cell mediate the effect on the association between TyG index and multiple sclerosis (MS). Additionally, genetic variation of TCF7L2 and TNFSF13B were assessed to play a crucial role in the aforementioned associations supported by colocalization analysis. This study identified T2DM and IR related to increased risk of MS and RA. The analysis of relevant immune cells and shared genetic loci provides a novel direction for exploring comorbidity mechanisms.

The origin of human CD20+ T cells: a stolen identity?

Human T cells expressing CD20 play an important role in the defense against virus and cancer and are central in the pathogenesis of both malignancies and various autoimmune disorders. Therapeutic modulation of CD20+ T cells and the CD20 expression level is therefore of significant interest. In rodents, CD20 on T cells is likely the product of an active transfer of CD20 from a donor B cell interacting with a recipient T cell in a process termed trogocytosis. Whether the same applies to human CD20+ T cells is highly debated. Investigating this dispute showed that human CD20- T cells could achieve CD20 along with a series of other B-cell markers from B cells through trogocytosis. However, none of these B-cell markers were co-expressed with CD20 on human CD20+ T cells in blood or inflamed CSF, implying that additional mechanisms may be involved in the development of human CD20+ T cells. In support of this, we identified true naïve CD20+ T cells, measured endogenous production of CD20, and observed that CD20 could be inherited to daughter cells, contradicting that all human CD20+ T cells are a product of trogocytosis.

Current Knowledge about CD3+CD20+ T Cells in Patients with Multiple Sclerosis

Multiple sclerosis (MS) is a disease of the central nervous system (CNS) characterized by inflammation and autoimmune responses. This review explores the participation of T cells, particularly certain CD3+CD20+ T cells, in the clinical manifestations of MS and highlights their presence in diagnosed patients. These T cells show aberrant expression of CD20, normally considered a B-cell marker. In this review, relevant journal articles available in PubMed and CINAHL were identified by employing diverse search terms, such as MS, CD3+CD20+ T cells, the incidence and significance of CD3+CD20+ T cells in MS patients, and the impact of rituximab treatment. The search was limited to articles published in the ten-year period from 2014 to 2024. The results of this review suggest that most scholars agree on the presence of CD3+CD20+ T cells in cerebrospinal fluid. Emerging concepts relate to the fundamental role of CD20-expressing T cells in determining the target and efficacy of MS therapeutics and the presence of T cells in the cerebrospinal fluid of MS patients. The results clearly show that CD20+ T cells indicate disease chronicity and high disease activity.

An angel or a devil? Current view on the role of CD8+ T cells in the pathogenesis of myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) and the experimental autoimmune MG (EAMG) animal model are characterized by T-cell-induced and B-cell-dominated autoimmune diseases that affect the neuromuscular junction. Several subtypes of CD4+ T cells, including T helper (Th) 17 cells, follicular Th cells, and regulatory T cells (Tregs), contribute to the pathogenesis of MG. However, increasing evidence suggests that CD8+ T cells also play a critical role in the pathogenesis and treatment of MG.

MAIN BODY

Herein, we review the literature on CD8+ T cells in MG, focusing on their potential effector and regulatory roles, as well as on relevant evidence (peripheral, in situ, cerebrospinal fluid, and under different treatments), T-cell receptor usage, cytokine and chemokine expression, cell marker expression, and Treg, Tc17, CD3+CD8+CD20+ T, and CXCR5+ CD8+ T cells.

CONCLUSIONS

Further studies on CD8+ T cells in MG are necessary to determine, among others, the real pattern of the Vβ gene usage of autoantigen-specific CD8+ cells in patients with MG, real images of the physiology and function of autoantigen-specific CD8+ cells from MG/EAMG, and the subset of autoantigen-specific CD8+ cells (Tc1, Tc17, and IL-17+IFN-γ+CD8+ T cells). There are many reports of CD20-expressing T (or CD20 + T) and CXCR5+ CD8 T cells on autoimmune diseases, especially on multiple sclerosis and rheumatoid arthritis. Unfortunately, up to now, there has been no report on these T cells on MG, which might be a good direction for future studies.

Alterations in the innate and adaptive immune system in a real-world cohort of multiple sclerosis patients treated with ocrelizumab

B cell depletion by the anti-CD20 antibody ocrelizumab is effective in relapsing-remitting (RR) and primary progressive (PP) multiple sclerosis (MS). We investigated immunological changes in peripheral blood of a real-world MS cohort after 6 and 12 months of ocrelizumab. All RRMS and most PPMS patients (15/20) showed treatment response. Ocrelizumab not only reduced CD20+ B cells, but also numbers of CD20+ T cells. Absolute numbers of monocytes, dendritic cells and CD8+ T cells were increased, while CD56hi natural killer cells were reduced after ocrelizumab. The residual B cell population shifted towards transitional and activated, IgA+ switched memory B cells, double negative B cells, and antibody-secreting cells. Delaying the treatment interval by 2-3 months increased mean B cell frequencies and enhanced naive B cell repopulation. Ocrelizumab reduced plasma levels of interleukin(IL)-12p70 and interferon(IFN)-α2. These findings will contribute to understanding ineffective treatment responses, dealing with life-threatening infections and further unravelling MS pathogenesis.

CD20+ T cells: an emerging T cell subset in human pathology

Introduction

Although CD20 is classically a B cell marker, in the last three decades, dim expression has been noted on a subset of T cells as well that has been independently verified by a number of groups. Our understanding of these cells and their function is not well established.

Methods

A thorough review of original articles on CD20⁺T cells was undertaken of Pubmed by using combination of phrases including “CD20⁺”, “CD20-positive” and “T cells”. Articles in English were considered, and there was no time restriction.

Results

CD20⁺T cells express the standard T cell markers and, in comparison to CD20¯ T cells, appear to express greater inflammatory cytokines and markers of effector function. Although the ontogeny of these cells is still being established, the current theory is that CD20 may be acquired by trogocytosis from B cells. CD20⁺T cells may be found in healthy controls and in a wide range of pathologies including autoimmune diseases, haematological and non-haematological malignancies and human immunodeficiency virus (HIV) infections. One of the best studied diseases where these cells are found is multiple sclerosis (MS) where a number of therapeutic interventions, including anti-CD20 depletion, have been shown to effectively deplete these cells.

Conclusion

This review summarises the latest understanding of CD20⁺T cells, their presence in various diseases, their putative function and how they may be an ongoing target of CD20-depleting agents. Unfortunately, our understanding of these cells is still at its infancy and ongoing study in a wider range of pathologies is required.