Welcome to the Autoimmunity 2021 Congress Calendar

Background and Aims

Background and aims: TWEAK (TNF weak inducer of apoptosis) is a cytokine member of the TNF ligand superfamily. We have been the first to show that TWEAK produced by infiltrating monocytes/macrophages contributed to neuroinflammation during multiple sclerosis (MS). Moreover, we have also recently suggested on a small cohort of patients that soluble TWEAK levels were elevated in MS and were associated with disease activity. Here, our aims were to determine soluble TWEAK levels in a larger cohort of MS and to compare TWEAK levels in i) MS patients versus controls and ii) relapsing remitting MS (RRMS) patients vs progressive MS patients.

Methods

Methods: Serum samples from 200 patients with MS and controls were collected, and soluble TWEAK levels were evaluated by using a commercially available ELISA kit. The data of the first 103 MS patients and 20 controls are presented here.

Results

Results: Serum soluble TWEAK levels were significantly higher in MS patients than in controls (1031+/-388pg/ml, vs 864+/-209 pg/ml, p=0.048). Although soluble TWEAK levels were higher in RRMS patients (1071+/-441pg/ml) than in progressive MS patients (972+/-267pg/ml), this did not reach statistical significance. In the RRMS patients’ group, soluble TWEAK did not correlate with EDSS disability score (R=0.03, p=0.76).

Conclusions

Conclusions: We confirm here in an independent cohort that serum levels of TWEAK are higher in MS patients than in controls. Moreover, soluble TWEAK levels tend to be lower in progressive MS than in RRMS. Further studies examining clinical and MRI parameters (notably gadolinium enhancement) in our whole cohort are in progress.

Background and Aims

Pro-inflammatory age-associated IgD^-CD27^- double negative (DN) B cells are abnormally elevated in the peripheral blood and cerebrospinal fluid of multiple sclerosis (MS) patients. This study aimed to investigate the developmental and migratory phenotype and function of DN B cells in MS.

Methods

Expression of developmental markers was determined on DN, IgD^-CD27⁺ class-switched memory (CSM) and IgD⁺CD27^- naive B cells of healthy controls (HC, n=48) and MS patients (n=96) by flow cytometry. Pro-inflammatory chemokine receptors and the transcription factor T-bet, previously described in another pathological age-associated B cell subset, were measured on B cell subsets of HC (n=25) and MS patients (n=49). Using an in vitro chemotaxis assay, migration of MS (n=7) B cell subsets was studied.

Results

DN B cells are mature antigen-experienced cells as indicated by low CD5, CD10 and CD38 expression and IgG or IgA expression in the majority of cells. However, IgA⁺ and activated CD95⁺ cells were less frequent in DN versus CSM B cells. DN B cells showed the highest T-bet expression and similar expression of chemokine receptors CXCR3 and CXCR5 compared to naive and CSM B cells, respectively. MS DN B cells further showed a high migration capacity towards CXCL10 (CXCR3 ligand) and CXCL13 (CXCR5 ligand) that was similar to CSM B cells.

Conclusions

DN B cells resemble CSM B cells but are at an earlier maturation state. Their potential importance in MS pathology was underlined by their migration towards chemokines important for B cell migration through the blood-brain barrier in MS.

Background and Aims

Autoimmune myasthenia gravis (MG) is caused by autoantibodies directed against the acetylcholine receptor (AChR). In MG, the thymus is the effector tissue characterized by a chronic inflammation, defective regulatory T-cells and ectopic germinal centers (eGCs) (Berrih-Aknin 2014). A crosstalk between Th17 cells and thymic epithelial cells, mediated by IL-23 and IL-17, sustains thymic events supporting antibody production by B-cells found in eGCs (Villegas et al. 2019).

We analyzed the effect of blocking the IL-23/Th17 axis, on the thymus and MG clinical course in a MG preclinical mouse model.

Methods

Immune-deficient NSG mice were engrafted with AChR⁺ MG thymic biopsies (NSG-MG). The NSG-MG model recapitulates MG symptoms and development (Sudres et al. 2017). Twenty five days after engraftment, mice were treated with a monoclonal anti human IL-23 antibody. We assessed the treatment effects on the engrafted thymic biopsies, muscle homeostasis and on MG global clinical score.

Results

The treatment limited or stopped the activation of inflammatory T-cells (CD4⁺CCR6⁺ CCR4⁺ T-cells) in the thymus and the periphery. In addition, a decreased thymic expression of protein involved in eGC stabilization was observed. More, increased muscle regeneration gene expression and significant muscular improvements were observed and correlated with amelioration of clinical symptoms and global disease score.

Conclusions

Altogether these data suggest that an anti-IL-23 therapy could be beneficial in MG by acting on the thymic inflammatory state and on muscle physiology. The inhibition of IL-23 activates transduction pathways involved in antibody production and in muscle regeneration process favoring then disease amelioration.

Background and Aims

Thymomas are associated with a very high risk to develop Myasthenia Gravis (MG). Our objectives were to identify histological and biological parameters allowing an early diagnostic of thymoma patients susceptible to develop MG.

Methods

We conducted a detailed retrospective analysis from our MG patient database (n=1766) searching for differences between patients with thymoma-associated MG (MGT) and thymoma without MG (TOMA), in comparison with MG patients without thymoma (MG). We also performed multiplex and Simoa analyses to measure serum levels for 16 cytokines in these groups of patients and controls (n=14-22).

Results

We identified a set of parameters associated with MG development in thymoma patients: 1) detection of anti-acetylcholine receptor (AChR) antibodies, 2) development of B1 or B2 thymoma subtypes, 3) presence of ectopic thymic germinal centers (GCs), 4) local invasiveness of thymoma, and 5) being a woman under 50 years old. Among all these parameters, 58.8% of MGT patients displayed GCs with a positive correlation between the number of GCs and the anti-AChR titers. By immunohistochemistry, we found thymic GCs in the adjacent tissue of thymoma encircled by high endothelial venules (HEVs) that could favor peripheral cell recruitment. We also clearly associated MG symptoms with higher IFN-γ, IL-1β and sCD40L serum levels specifically in MGT compared to TOMA patients.

Conclusions

Altogether, these analyses had allowed the clear identification of histological, in particular the presence of GCs, and biological parameters that would help to evaluate the probability of the outcome of MG post-operatively in thymoma patients.

Background and Aims

Glucocorticoids (GCs) are used for the treatment of relapse multiple sclerosis.(MS). Decreased sensitivity to GCs in MS patients has been associated with lack of suppressive effect of GCs on inflammatory molecules, increased resistance to apoptosis which in turn affect the response to high intravenous methylprednisolone (IVMP). We investigated GC-sensitivity by measuring the effect of IVMP treatment on transactivation of anti-inflammatory, anti-apoptotic and apoptotic genes (GILZ, MCL-1 and NOXA respectively) in accordance to clinical outcome.

Methods

We studied 24 MS patients: clinically isolated syndrome (CIS/n=9), relapsing remitting (RRMS/n=8) and secondary progressive (SPMS/n=7) under relaspe. Patients underwent treatment with IVMP (1000mg/day) for 5 consecutive days. Blood was drawn on before and 1 hour after IVMP on day 1 and also 1h after 5th IVMp. GIlZ, MCL-1 and NOXA gene expression was determined by qPCR. The Expanded Disability Status was also evaluated before and after IVMP (on 5th day) and all patients were divided according to their clinical response into two groups.

Results

Our data demonstrate that the GILZ and MCL-1 gene expression were significantly higher after first IVMP injection (day1) in clinical responders compared to non-clinical responders (p≤0.05). However, the NOXA gene expression 1h after 5th IVMP was significantly higher in clinical responders as compared to non-clinical responders (p≤0.05).

Conclusions

Our findings suggest that the differential GILZ and MCL-1 gene expression between clinical responders and non-clinical responders implicate the importance of GILZ and MCL-1 as possible markers for predicting glucocorticoid sensitivity and response to GC-therapy in MS patients after the first IVMP treatment.

Background and Aims

Myasthenia gravis (MG) is a rare neuromuscular disease due to autoantibodies against the acetylcholine receptor (AChR). Thymic abnormalities are associated with MG such as ectopic germinal center development with B cells producing anti-AChR antibodies. The MG thymus is characterized by the overexpression of interferon (IFN)-β and IFN-I induced genes (ISGs). IFN-β orchestrates thymic changes associated with MG and favors the autoimmune reaction against α-AChR. An IFN-I signature is observed in periphery in other autoimmune diseases such as SLE or dermatomyositis. Our objective was to search for an IFN-I signature in periphery in MG patients.

Methods

Serum and PBMCs were collected from early-onset MG (EOMG) patients and age-matched healthy donors. The expression of IFN-α, IFN-β and six ISGs have been measured by RT-qPCR in PBMCs. The serum levels of IFN-α and IFN-β have been measured by Simoa and ELISA.

Results

In PBMCs, no increased expression of IFN-α, IFN-β or of ISGs, except RASD2, were observed in MG either in patients treated or not with corticosteroids or in patients thymectomized or not.

In the serum, no increased expression of IFN-α and IFN-I were observed in MG patients even when patients were stratified according to the severity of the disease or to their treatments (corticosteroids, thymectomy).

Conclusions

Altogether, these results showed that there is no IFN-I signature in PBMCs or in the serum of EOMG patients. The IFN-I signature is confined to the thymus with no apparent release in the periphery.

Background and Aims

Chronic neuroinflammation and autoimmunity are key pathological hallmarks of multiple sclerosis (MS) and entail a dysregulation of the natural process to resolve inflammation which is orchestrated by the super-family of specialized pro-resolving mediators (SPMs), that include lipoxins (LXs), resolvins (Rvs), protectins (PDs) and maresins (MaRs), that have been shown to modulate critical subsets of autoreactive T cells. Yet the role of resolution of inflammation in multiple sclerosis is still unknown.

Methods

We performed targeted-metabololipidomics in the plasma of healthy donors and MS patients with different clinical forms of disease and we analyzed the expression of SPM biosynthetic enzymes and receptors in leukocytes obtained from MS patients. Furthermore, we investigated the response of key pathogenic cells involved in MS to specifically altered SPMs by means polychromatic flow cytometry and using a primary model of blood brain barrier.

Results

We identified a unique lipid mediator signature associated with MS clinical forms and we reported an impaired plasma production of specific SPMs (e.g. RvD1 and PD1), which were strongly reduced along disease progression. These findings were supported by impaired/altered expression of key SPM biosynthetic enzymes and receptors (e.g. 15-LOX, GRP32, GRP18) in leukocytes of MS patients. Furthermore, RvD1 and PD1 reduced activation and cytokine production from monocytes of MS patients and inhibited inflammation-induced blood-brain barrier dysfunction.

Conclusions

Overall, we here provide critical evidence of a failed resolution pathway within the neuro-immune axis in MS, suggesting new insights into its autoimmune pathogenesis and providing innovative diagnostic and therapeutic approaches.

Background and Aims

Regulatory T cells (Tregs) CD4⁺CD25⁺FoxP3⁺СD127^low provide among others regulation of inflammatory reactions by suppressing effector cells. The function and the numbers of Tregs are compromised in patients with Remitting Relapsing Multiple Sclerosis (RRMS). We aimed to determine whether adoptive transfer of expanded ex vivo autologous Tregs (eTregs) into patients with RRMS are safe and tolerable, and if they can restore the patients Treg deficit leading to disease-modifying effects.

Methods

In our study we traced differentiation of eTregs CD4⁺CD25⁺FoxP3⁺СD127^low after short-term cultivation of initial CD4⁺ T cells of 37 RRMS patients. Fourteen patients were injected once with 300 - 450x10⁶ eTregs and followed for 24 weeks.

Results

The resulting cell population consisted of 96,2-98,5% Tregs with increased capacity to suppress proliferation of effector target cells. The RRMS patients injected with Tregs reported minor and only temporary side effects. Two weeks after the cell injection the Treg level in the patients’ peripheral blood samples was elevated with a tendency to slowly decline during the following 2-3 months. The number of relapses was reduced by 76% in the RRMS patients. The expanded Tregs were seen to be twice as active in respect to up-regulation of FOXP3 and Helios genes expression compared to the patients Tregs at time of harvesting.

Conclusions

Infusion of eTregs is safe and feasible leading to a significant reduction in relapse and leading to EDSS stabilization indicating that the method could hold the potential to become a new treatment option for RRMS patients.