Biology subjects

Vural, A.

Publications and source records attributed to Vural, A..

8 recordsLinked to original sources

bioRxiv2026

Glucose-Responsive CD20+ Cytotoxic T Cells: A Novel Pro-inflammatory Mediator in the Immunopathogenesis of Type 2 Diabetes

ObjectiveAlthough T-cell-mediated inflammation is a hallmark of Type 2 Diabetes (T2D), the contribution of CD20-expressing T cells--a highly potent subset recently implicated in various autoimmune conditions--to T2D pathogenesis remains unknown. This study aimed to characterize the frequency, functional profile, and glucose-responsiveness of CD20+ cytotoxic T lymphocytes (CTLs) in patients with T2D. Research Design and MethodsPeripheral blood mononuclear cells (PBMCs) from 25 treatment-naive T2D patients and 20 age-matched healthy controls (HC) were analyzed using multicolor flow cytometry. We assessed the frequency of CD3+CD8+CD20+ cells and their production of cytotoxic molecules (Granzyme B, Perforin, Granzyme K) and pro-inflammatory cytokines (IFN-{gamma}, TNF-, GM-CSF). To further establish the link with hyperglycemia, HC-derived CTLs were exposed to increasing glucose concentrations (100-450 mg/dL) in vitro. Single-cell RNA sequencing (scRNA-seq) data from a public T2D dataset was utilized to validate the molecular signature of MS4A1 (CD20)+ CTLs. ResultsThe frequency of circulating CD20+ CTLs was significantly elevated in T2D patients compared to HCs (p<0.0001) and demonstrated a strong positive correlation with HbA1c, fasting glucose, and triglyceride levels. Notably, CD20+ CTLs from T2D patients exhibited a "hyperfunctional" phenotype, characterized by significantly higher degranulation (CD107a), elevated expression of Granzymes B/K and Perforin, and increased production of IFN-{gamma} and TNF- compared to HCs (p<0.01 for all). In contrast, no such differences were observed in the CD20-CTL compartment. In vitro experiments revealed that escalating glucose levels directly enhanced the proliferation and cytotoxic potential of CD20+ CTLs, suggesting a nutrient-sensing mechanism. scRNA-seq analysis further confirmed the distinct pro-inflammatory and effector transcriptional profile of MS4A1+ T cells in T2D. ConclusionsOur findings identify CD20+ CTLs as a novel, glucose-sensitive, and hyperfunctional immune subset in T2D. The strong correlation between these cells and clinical metabolic parameters suggests that CD20+ CTLs may act as a critical link between chronic hyperglycemia and systemic inflammation, representing a potential new therapeutic target for immunomodulation in T2D.

immunology↗

bioRxiv2026

CD8+CD20+ Cytotoxic T Lymphocytes Exhibit Augmented Degranulation and Pro-inflammatory Potential in Multiple Sclerosis

The effectiveness of CD20-targeting therapies in multiple sclerosis (MS) underscores the role of B cells in the disease, yet the limited success of other B cell-specific treatments suggests additional mechanisms at play. Intriguingly, CD20 is also expressed on a subset of highly active memory T cells, particularly cytotoxic CD8+ T lymphocytes (CTLs). This study investigated the functional characteristics of CD8+CD20+ CTLs in MS. We observed a significant increase in CD8+CD20+ CTL prevalence in MS patients, with enhanced infiltration into the cerebrospinal fluid. Consistent with prior reports, these cells exhibited heightened proliferation and production of IFN-{gamma}, TNF-, and GM-CSF. Notably, we demonstrate for the first time that CD8+CD20+ CTLs display escalated degranulation and produce significantly higher levels of Granzyme B, Perforin, and Granzyme K compared to their CD20-counterparts, with further augmentation in pwMS compared to healthy controls. These findings suggest that in MS, CD8+CD20+ CTLs are actively recruited to the CNS, exhibiting enhanced cytotoxicity and a potent pro-inflammatory profile, particularly through elevated Granzyme K production, contributing significantly to the chronic inflammatory milieu and immunopathogenesis of MS.

immunology↗

bioRxiv2025

Reactive Pericytes Lead to Microvascular Dysfunction and Cortical Neurodegeneration During Experimental Autoimmune Encephalomyelitis

The mechanisms underlying neurodegeneration in multiple sclerosis remain incompletely understood. In this study, we aimed to investigate the role of vascular dysfunction in cortical neurodegeneration using a chronic cranial window model of experimental autoimmune encephalomyelitis in mice. After the induction of experimental autoimmune encephalomyelitis with myelin oligodendrocyte glycoprotein peptides in C57BL/6J mice, we assessed cerebrovascular reactivity though a chronic cranial window using laser speckle contrast imaging and intrinsic optical signal imaging in awake animals. We observed a significant reduction in cortical cerebrovascular reactivity during peak inflammation in the EAE group, as detected by laser speckle contrast imaging after 5% hypercapnia (p=0.04) and optical signal imaging after whisker stimulation (p=0.008). Histological analysis revealed a diffuse increase in CD13+ pericyte coverage (p=0.001), accompanied by focal IgG deposition within the microvascular lumen (p=0.04) and increased amount of CD45+ leukocytes stalled in microvessels (p=0.03) in the cortex of experimental autoimmune encephalomyelitis mice. Microglial activation was also present in the cortex of experimental autoimmune encephalomyelitis mice (p=0.04) and was particularly evident around microvessels with IgG deposition. Subpial and intracortical foci exhibiting loss of NeuN reactivity (p=0.03) and axonal loss (p=0.007) were detected in experimental autoimmune encephalomyelitis, but not in control mice. Altogether, these results demonstrate that microvascular function and neurovascular unit elements are globally affected in the cortex during autoimmune neuroinflammation and is related to neurodegeneration.

neuroscience↗

bioRxiv2025

CD20+ natural killer cells are polyfunctional, memory-like cells that are enriched in inflammatory disorders

While CD20 was initially characterized as a B cell-specific marker, its expression on memory T cells has expanded our understanding of this molecules distribution and function. Here, we identify a previously unrecognized CD20-expressing NK cell population and demonstrate its functional significance. CD56+CD20+ NK cells exhibit hallmarks of cellular activation, including elevated NKp46, CD69, and CD137 expression, enhanced proliferative capacity, and increased production of inflammatory cytokines (IFN-{gamma}, GM-CSF, TNF-, IL-10). Functional analyses revealed enhanced cytotoxicity against K562 targets, correlating with increased expression of cytolytic mediators including granzymes A, B, and K, perforin, FASL, and TRAIL. Single-cell transcriptional profiling demonstrated that MS4A1-expressing NK cells possess a distinct molecular signature characterized by elevated granzyme K expression and memory-like features. These cells preferentially localize to secondary lymphoid organs and accumulate in inflammatory tissues. Notably, CD56+CD20+ NK cells are enriched in multiple inflammatory conditions, including multiple sclerosis, autoimmune hepatitis, hepatitis B infection, hepatocellular carcinoma, and lung cancer. Treatment with rituximab depletes this population, suggesting potential therapeutic implications. Our findings establish CD20+ NK cells as a functionally distinct lymphocyte subset with enhanced effector capabilities and tissue-homing properties, providing new insights into immune regulation in inflammatory diseases. One Sentence SummaryOur study reveals expression of CD20 by NK cells, in relation with enhanced functionality, memory-like features, and inflammation.

immunology↗

bioRxiv2024

Sex-specific DNA methylation differences in Amyotrophic lateral sclerosis

Sex is an important covariate in all genetic and epigenetic research due to its role in the incidence, progression and outcome of many phenotypic characteristics and human diseases. Amyotrophic lateral sclerosis (ALS) is a motor neuron disease with a sex bias towards higher incidence in males. Here, we report for the first time a blood-based epigenome-wide association study meta-analysis in 9274 individuals after stringent quality control (5529 males and 3975 females). We identified a total of 226 ALS saDMPs (sex-associated DMPs) annotated to a total of 159 unique genes. These ALS saDMPs were depleted at transposable elements yet significantly enriched at enhancers and slightly enriched at 3UTRs. These ALS saDMPs were enriched for transcription factor motifs such as ESR1 and REST. Moreover, we identified an additional 10 genes associated with ALS saDMPs through chromatin loop interactions, suggesting a potential regulatory role for these saDMPs on distant genes. Furthermore, we investigated the relationship between DNA methylation at specific CpG sites and overall survival in ALS using Cox proportional hazards models. We identified two ALS saDMPs, cg14380013 and cg06729676, that showed significant associations with survival. Overall, our study reports a reliable catalogue of sex-associated ALS saDMPs in ALS and elucidates several characteristics of these sites using a large-scale dataset. This resource will benefit future studies aiming to investigate the role of sex in the incidence, progression and risk for ALS.

genomics↗

bioRxiv2024

A Novel Mouse Model Demonstrates In Vivo Replenishment of Central Nervous System Pericytes After Successful Acute Ablation

Central nervous system (CNS) pericytes play crucial roles in vascular development and blood-brain barrier maturation during prenatal development, as well as in regulating cerebral blood flow in adults. They have also been implicated in the pathogenesis of numerous neurological disorders. However, the behavior of pericytes in the adult brain after injury remains poorly understood, partly due to limitations in existing pericyte ablation models. To investigate pericyte responses following acute ablation, we developed a tamoxifen-inducible pericyte ablation model by crossing PDGFR{beta}-P2A-CreERT2 and Rosa26-DTA176 transgenic mouse lines. Using this model, we studied the effects of different tamoxifen doses and conducted histological examinations 15 and 60 days post-injection to assess both short- and long-term impacts of pericyte ablation. Our results demonstrate that a low dose of tamoxifen effectively ablates CNS pericytes in mice without reducing survival or causing significant systemic side effects, such as weight loss. Additionally, we found that the extent of pericyte depletion varies between the cortex and the spinal cords gray and white matter regions. Importantly, both pericyte coverage and numbers increased in the weeks following acute ablation, indicating the regenerative capacity of CNS pericytes in vivo. This model offers a valuable tool for future studies on the role of pericytes in neurological disorders, overcoming the limitations of constitutive pericyte ablation models.

neuroscience↗

bioRxiv2023

Biomolecular Condensates defined by Receptor Independent Activator of G protein Signaling: Properties and Regulation

Activator of G-protein Signaling 3 (AGS3), a receptor independent activator of G-protein signaling, oscillates among different subcellular compartments in a regulated manner including punctate entities referred to as biomolecular condensates (BMCs). The dynamics of the AGS3 oscillation and the specific subcompartment within the cell is intimately related to the functional diversity of the protein. To further address the properties and regulation of AGS3 BMCs, we asked initial questions regarding a) the distribution of AGS3 across the broader BMC landscape with and without cellular stress, and b) the core material properties of these punctate structures. Cellular stress (oxidative, pHi, thermal) induced the formation of AGS3 BMCs in two cell lines (Hela, COS7) as determined by fluorescent microscopy. The AGS3-BMCs generated in response to oxidative stress were distinct from stress granules (SG) as defined by the SG marker protein G3BP1 and RNA processing BMCs defined by the P-body protein Dcp1a. Immunoblots of fractionated cell lysates indicated that cellular stress shifted AGS3 to the membrane pellet fraction, whereas the protein markers for stress granules (G3BP1) SG- BMCs remained in the supernatant. We next asked if the formation of the stress-induced AGS3 BMCs was regulated by protein binding partners involved with signal processing. The stress-induced generation of AGS3 BMCs was regulated by the signaling protein Gi3, but not by the AGS3 binding partner DVL2. Finally, we addressed the fluidity or rigidity of the stress-induced AGS3-BMCs using fluorescent recovery following photobleaching of individual AGS3-BMCs. The AGS3-BMCs indicated distinct diffusion kinetics that were consistent with restricted mobility of AGS3 within the stress-induced AGS3-BMCs. These data suggest that AGS3 BMCs represents a distinct class of stress granules that define a new type of BMC that may serve as previously unappreciated signal processing nodes. Summary statementAGS3 assembles into distinct biomolecular condensates in response to cell stress and this assembly is selectively regulated by AGS3 binding partners involved in signal transduction within the cell.

cell biology↗

bioRxiv2018

The Project MinE databrowser: bringing large-scale whole-genome sequencing in ALS to researchers and the public.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive fatal neurodegenerative disease affecting 1 in 350 people. The aim of Project MinE is to elucidate the pathophysiology of ALS through whole-genome sequencing at least 15,000 ALS patients and 7,500 controls at 30X coverage. Here, we present the Project MinE data browser (databrowser.projectmine.com). a unique and intuitive one-stop, open-access server that provides detailed information on genetic variation analyzed in a new and still growing set of 4,366 ALS cases and 1,832 matched controls. Through its visual components and interactive design, the browser specifically aims to be a resource to those without a biostatistics background and allow clinicians and preclinical researchers to integrate Project MinE data into their own research. The browser allows users to query a transcript and immediately access a unique combination of detailed (meta)data, annotations and association statistics that would otherwise require analytic expertise and visits to scattered resources.

genomics↗