0000000000076332
AUTHOR
Magdalena Paterka
Cladribine exerts an immunomodulatory effect on human and murine dendritic cells
Cladribine is a purine nucleoside analog developed to treat lymphoid malignancies. Reported therapeutic benefits for the autoimmune disease multiple sclerosis indicate additional immunomodulatory effects beyond the well-characterized cytotoxic activity causing lymphopenia. Here, we demonstrate that cladribine reduces the secretion of inflammatory cytokines and chemokines by murine and human dendritic cells, the most potent antigen-presenting cells. This compound also modulates the expression of the activation markers CD86 and MHC II. Furthermore, cladribine affects the T cell priming capacity of dendritic cells, resulting in reduced induction of interferon-γ- and tumor necrosis factor-α-pro…
Role of Sortilin in Models of Autoimmune Neuroinflammation
Abstract The proneurotrophin receptor sortilin is a protein with dual functions, being involved in intracellular protein transport, as well as cellular signal transduction. The relevance of the receptor for various neuronal disorders, such as dementia, seizures, and brain injury, is well established. In contrast, little is known about the role of sortilin in immune cells and inflammatory diseases. The aim of our study was to elucidate the distribution of sortilin in different immune cell types in mice and humans and to analyze its function in autoimmune CNS inflammation. Sortilin was expressed most profoundly in murine and human macrophages and dendritic cells and to a much lesser extent in…
New candidates for CD4 T cell pathogenicity in experimental neuroinflammation and multiple sclerosis
Multiple sclerosis is a chronic autoimmune demyelinating disease of the central nervous system, which is thought to be triggered by environmental factors in genetically susceptible individuals leading to activation of autoreactive T lymphocytes. Large multi-centre genome-wide association studies have identified multiple genetic risk loci in multiple sclerosis. In this study, we investigated T cell transcriptomic changes in experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis. We correlated these findings with the multiple sclerosis risk genes postulated by the most recent Immunochip analysis and found that multiple sclerosis susceptibility genes were significant…
FTY720 (fingolimod) treatment tips the balance towards less immunogenic antigen-presenting cells in patients with multiple sclerosis.
Objective: We aimed to clarify whether fingolimod has direct effects on antigen-presenting cells in multiple sclerosis patients. Methods: Frequency and phenotype of directly ex vivo dendritic cells and monocytes were analyzed in 43 individuals, including fingolimod-treated and untreated multiple sclerosis patients as well as healthy subjects. These cells were further stimulated with lipopolysaccharide to determine functional effects of fingolimod treatment. Results: Absolute numbers of CD1c+ dendritic cells and monocytes were not significantly reduced in fingolimod-treated patients indicating that fingolimod did not block the migration of antigen-presenting cells to peripheral blood. CD86 w…
Modulation of dendritic cell properties by laquinimod as a mechanism for modulating multiple sclerosis.
Laquinimod is an orally administered compound that is under investigation in relapsing-remitting multiple sclerosis. To understand the mechanism by which laquinimod exerts its clinical effects, we have performed human and murine studies assessing its immunomodulatory properties. In experimental autoimmune encephalomyelitis, the therapeutic administration of laquinimod beginning during the recovery of SJL mice, prevented further relapses as expected and strongly reduced infiltration of CD4+ and CD8+ T cells in the central nervous system. We hypothesized that this beneficial effect was mediated by dendritic cells, since we and others found a modulation of different dendritic cell subsets unde…
Cross-recognition of a myelin peptide by CD8+ T cells in the CNS is not sufficient to promote neuronal damage.
Multiple sclerosis (MS) is an inflammatory disease of the CNS thought to be driven by CNS-specific T lymphocytes. Although CD8+T cells are frequently found in multiple sclerosis lesions, their distinct role remains controversial because direct signs of cytotoxicity have not been confirmedin vivo. In the present work, we determined that murine ovalbumin-transgenic (OT-1) CD8+T cells recognize the myelin peptide myelin oligodendrocyte glycoprotein 40–54 (MOG40–54) bothin vitroandin vivo. The aim of this study was to investigate whether such cross-recognizing CD8+T cells are capable of inducing CNS damagein vivo. Using intravital two-photon microscopy in the mouse model of multiple sclerosis, …
Gatekeeper role of brain antigen‐presenting CD11c + cells in neuroinflammation
Multiple sclerosis is the most frequent chronic inflammatory disease of the CNS. The entry and survival of pathogenic T cells in the CNS are crucial for the initiation and persistence of autoimmune neuroinflammation. In this respect, contradictory evidence exists on the role of the most potent type of antigen-presenting cells, dendritic cells. Applying intravital two-photon microscopy, we demonstrate the gatekeeper function of CNS professional antigen-presenting CD11c(+) cells, which preferentially interact with Th17 cells. IL-17 expression correlates with expression of GM-CSF by T cells and with accumulation of CNS CD11c(+) cells. These CD11c(+) cells are organized in perivascular clusters…
The role of CD8+ T cells and their local interaction with CD4+ T cells in myelin oligodendrocyte glycoprotein35-55-induced experimental autoimmune encephalomyelitis.
Abstract T cells have an essential role in the induction of multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). Although for CD4+ T cells it is well established that they contribute to the disease, less is known about the role of CD8+ T cells. Our aim was to determine the individual contribution of CD4+ and CD8+ T cells in myelin oligodendrocyte glycoprotein (MOG)35–55–induced EAE. We investigated MOG35–55–activated CD8+ T cells to clarify their potential to induce or attenuate EAE. We monitored the behavior of CD8+ T cells and their interaction with CD4+ T cells directly at the site of inflammation in the CNS using intravital imaging of the brainstem of…
Flow cytometric analysis of T cell/monocyte ratio in clinically isolated syndrome identifies patients at risk of rapid disease progression.
Background: Multiple sclerosis is a chronic inflammatory central nervous system disease diagnosed by clinical presentation and characteristic magnetic resonance imaging findings. The role of cerebrospinal fluid (CSF) analysis has been emphasized in particular in the context of differential diagnosis in patients with a first episode suggestive of multiple sclerosis. Objective: We investigated here the potential additional value of analysis of CSF cellularity by fluorescence activated cell sorting (FACS) in the setting of a routine diagnostic work-up in our inpatient clinic. Methods: CSF cells from back-up samples from patients with suspected chronic inflammatory central nervous system disord…
The role of NFATc2 in chronic autoimmune neuroinflammation
Dimethyl fumarate (DMF), a fumaric acid ester with potential immunomodulatory and neuroprotective effect, was recently approved as treatment for relapsing–remitting multiple sclerosis (MS). DMF ameliorates the clinical course of experimental autoimmune encephalomyelitis (EAE), the murine model of MS, where it exerts a neuroprotective action, reducing demyelination and axonal loss. We hypothesized that these effects are mediated, at least in part, through its action on microglia. We used a microglial cell line (N9) activated with lipopolysaccharide (LPS) to analyze the effect of monomethyl fumarate (MMF), a bioactive metabolite of DMF, in vitro. We show that MMF reverts the molecular phenoty…
Dendritic cells tip the balance towards induction of regulatory T cells upon priming in experimental autoimmune encephalomyelitis
Counter-balancing regulatory mechanisms, such as the induction of regulatory T cells (Treg), limit the effects of autoimmune attack in neuroinflammation. However, the role of dendritic cells (DCs) as the most powerful antigen-presenting cells, which are intriguing therapeutic targets in this context, is not fully understood. Here, we demonstrate that conditional ablation of DCs during the priming phase of myelin-specific T cells in experimental autoimmune encephalomyelitis (EAE) selectively aborts inducible Treg (iTreg) induction, whereas generation of T helper (Th)1/17 cells is unaltered. DCs facilitate iTreg induction by creating a milieu with high levels of interleukin (IL)-2 due to a st…
In Vivo Imaging of Partially Reversible Th17 Cell-Induced Neuronal Dysfunction in the Course of Encephalomyelitis
SummaryNeuronal damage in autoimmune neuroinflammation is the correlate for long-term disability in multiple sclerosis (MS) patients. Here, we investigated the role of immune cells in neuronal damage processes in animal models of MS by monitoring experimental autoimmune encephalomyelitis (EAE) by using two-photon microscopy of living anaesthetized mice. In the brainstem, we detected sustained interaction between immune and neuronal cells, particularly during disease peak. Direct interaction of myelin oligodendrocyte glycoprotein (MOG)-specific Th17 and neuronal cells in demyelinating lesions was associated with extensive axonal damage. By combining confocal, electron, and intravital microsc…