Welcome to the 13th International Congress on Autoimmunity interactive program

Abstract Body

Multiple sclerosis (MS) can be a devastating disease causing significant physical, cognitive and mental disabilities. With currently available disease modifying therapies (DMTs) for MS, in particular the higher efficacy ones (namely natalizumab, alemtizimab, cladribine, ocrelizumab and ofatumumab), the bar for modern treatment goals has been raised from reducing relapse frequency, delaying disability progression and preventing new or enhancing MRI lesions to freedom from clinical and MRI disease activity (NEDA), stabilizing function and/or improving pre-existing disability, reducing brain atrophy and allowing for healthy aging. The best treatment strategy for MS is still debated. However, multiple lines of evidence support the approach of using high efficacy therapies (HET) early in the course of the disease in order to achieve these goals. Early aggressive therapy has been shown to slow disability accumulation and improve the course of MS; Comparative studies demonstrate the superiority of early treatment with HET over platform therapies or later treatment; Real world cohort studies confirm the superiority of HET in delaying disability progression and secondary progressive MS; and patients also prefer more efficacious therapies and tend to underestimate therapy risks and overestimate benefits. Accumulating clinical experience, appropriate individualized treatment selection, risk mitigation strategies and risk-management programs make risk profile of most HET predictable and manageable and help reduce risks and increase benefits of early HET for MS. Two ongoing large pragmatic randomized clinical trials, TREAT-MS and DELIVER-MS will help to evaluate the place of early aggressive therapy in the treatment algorithm of MS

Abstract Body

Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system (CNS). Traditionally, B cells were considered to be passively involved in MS pathogenesis by the production of autoantibodies. However, the success of B cell depleting strategies in MS treatment has emphasized the more central role of B cells in MS pathology with an emphasis on antibody-independent functions such as cytokine secretion and stimulation of T cell responses by antigen presentation and costimulation.

B cell biology is highly complex, as different B cell subsets exist depending on their maturation state. Transitional B cells enter the circulation following development in the bone marrow. After antigen recognition, immunoglobulin (Ig)D⁺CD27^- naive B cells mature into memory B cells which further optimize antigen binding. The population of memory B cells consists of IgD⁺CD27⁺ non class-switched memory (NCSM) B cells and IgD^-CD27⁺ class-switched memory (CSM) B cells. IgD^-CD27^- double negative (DN) B cells are also mostly mature antigen-experienced cells with a pro-inflammatory function.

An important focus of our current research is unravelling the pro-inflammatory phenotype and function of DN B cells in MS patients. Previously, we reported abnormally elevated frequencies of DN B cells in the peripheral blood and cerebrospinal fluid (CSF) of MS patients. Expression of antigen presentation and costimulatory molecules on DN B cells indicated their potential to induce T cell responses. Further, DN B cells produced the pro-inflammatory cytokines lymphotoxin-α and tumor necrosis factor-α and the cytotoxic molecule granzyme B following ex vivo stimulation. In addition, we reported that DN B cells resemble mature CSM B cells based on the expression of developmental markers (CD5, CD10, CD38) and Ig isotypes (IgM, IgA, IgG). Preliminary data showed that DN B cells expressed cell adhesion molecules (lymphocyte function-associated antigen 1 (LFA-1), very late antigen 4 (VLA-4), activated leukocyte cell adhesion molecule (ALCAM)) and pro-inflammatory chemokine receptors (C-X-C chemokine receptor (CXCR)3 and CXCR5), all involved in B cell migration towards the CNS. In addition, DN B cells demonstrated a high migration capacity towards the pro-inflammatory chemokines C-X-C chemokine ligand (CXCL)10 (CXCR3 ligand) and CXCL13 (CXCR5 ligand). The expression of the T-box transcription factor T-bet, previously described in a pathological age-associated B cell subset, was found in 22 [3.3, 52.0]% of MS DN B cells.

Thus, DN B cells are abnormally elevated in MS patients and could migrate into the CNS. They could contribute to inflammation by induction of T cell responses and pro-inflammatory cytokine production. Further research on DN B cells could lead to novel targets for more specific MS therapies as well as increase our insight into the involvement of B cells in MS pathogenesis.

Background and Aims

Physical exercise (PE) impacts various autoimmune diseases. Accordingly, clinical trials demonstrated the safety of PE in multiple sclerosis (MS) patients and indicated beneficial outcomes. There is also an increasing body of research on the beneficial effects of exercise on experimental autoimmune encephalomyelitis (EAE), the animal model of MS, and various mechanisms underlying these effects were suggested. However, despite the documented favorable impact of PE on our health, we still lack a thorough understanding of its effects on autoimmune neuroinflammation and specific guidelines of PE therapy for MS patients are lacking.

Methods

To that end, current findings on the impact of PE on autoimmune neuroinflammation, both in human MS and animal models are reviewed. The concept of personalized PE therapy for autoimmune neuroinflammation is discussed, and future research for providing biological rationale for clinical trials to pave the road for precise PE therapy in MS patients is described.

Results

PE modifies the pathogenesis of disease mainly due to modulation of encephalitogenic T cell responses, though direct neuroprotective mechanisms mediated by PE can also be involved. Research in animal models indicates that the effects of PE depend on several factors, particularly the intensity and the training paradigm.

Conclusions

In-depth understanding of the cellular and molecular mechanisms underlying the beneficial effects of exercise training on EAE and elucidating the training parameters that induce the optimal immunomodulation and/or neuroprotection are essential for designing effective clinical treatments in MS patients and other patients with autoimmune diseases.

Background and Aims

The systemic analysis of the entire autoantigen repertoire, i.e. the autoantigenome, in an “omics-like” way (autoantigenomics) aims to capture the enormous biodiversity in the autoantigenomes and to enable better understanding of the concerted character of antibody-related immune responses. In recent years, the concept of autoantigenomics has been developed and applied for different diseases (e.g. Covid-19). Here, we aim to summarize the progress of autoantigenomics in the last 3 years and to present our recent example from neurology.

Methods

We systematically analyzed the repertoire of antibodies against immune system pathways in patients with sensory neuronopathy (SNN) via two protein arrays: ProtoArray covering 7,634 human proteins for 38 SNN patients and 14 controls (7 other neuropathies, 7 healthy controls [HC]); HuProt array covering 15,797 human proteins for 12 SNN and 31 controls (22 other neuropathies, 9 HC). We performed overrepresentation analyses (Reactome database, PantherDB) and cytokine profiling (Bio-Plex ProTM Reagent Kit III).

Results

SNN sera interacted with a significantly higher number of proteins of immune system pathways than controls. More pathways of the innate immune system, adaptative immune system, and cytokine signaling system were overrepresented in SNN than controls. Anti-FGFR3-positive SNN were more reactive with immune system proteins than anti-FGFR3-negative patients, regarding numbers of both targeted proteins and overrepresented pathways. IFN alpha-2 and TNF alpha levels were higher in anti-FGFR3-negative than in -positive patients.

Conclusions

The antibody repertoire of SNN may be an imprint of disease-relevant immunological pathways. The identified autoantigenome involves cytokine signaling pathways that may also participate to the pathogenesis of Sjögren Syndrome.

Background and Aims

Recurrent thrombotic events are common in APS. Generally, a first arterial thrombosis is followed by an arterial event and an initial venous thrombosis is followed by a venous event; however, switches among vascular sides were described: factors determining the predilection for the venous or arterial circulation are not known. Our aim is to analyze the features of APS patients with recurrent thrombosis in both venous and arterial vessels.

Methods

Consecutive patients with diagnosis of thrombotic APS, followed during 1985-2019 period in four European Centers, were retrospectively enrolled.

Results

The cohort included 415 patients (table 1). During follow-up, despite the standard therapy (anticoagulant in 69%, antiaggregant in 56%, combination in 36%), ≥1 recurrent event occurred in 176/415 subjects, especially males (37% vs 27%; p:0.027), with arterial hypertension (37% vs 26%; p:0.016), protein S deficiency (7% vs 2%; p:0.036) and that presented with initial venous thrombosis (70% vs 56%; p:0.003). Among recurrencies, vascular side switches occurred in 54/176 cases. Comparing patients who experienced thrombotic events in both venous and arterial circulation with those who did not, the former presented more frequently triple aPL positivity (65% vs 39%; p:0.005), while no differences in demographics, initial presentation and concomitant risk factors were observed.

Conclusions

In this large cohort of APS patients, thrombotic events occurred both in venous and arterial districts in 54/415 (13%) subjects, especially in triple aPL positive patients. Triple aPL positivity defines the serological profile at highest risk of thrombosis and it seems associated to an increased possibility of switch in the involved vascular side.

Background and Aims

Myasthenia gravis (MG), is an antibody-mediated, T-cell dependent autoimmune disease. In MG autoantibodies target mostly the muscle nicotinic acetylcholine receptor (nAChR), located at the neuromuscular junction. Currently, MG is usually treated with non-specific immunomodulatory agents, which may have several side effects. Therefore, there is a need for the development of novel, more specific therapies. Reprogramming the specific autoreactive immune cells in order to restore the immune tolerance is a compelling antigen specific approach.

Methods

We investigated the therapeutic potency of the human nAChR α1 subunit extracellular domain (α1-ECD), which contains several MG T and B cell epitopes, using a mutated form of α1-ECD with increased solubility. The in vivo studies were performed in a rat experimental autoimmune MG (EAMG) animal model, induced by immunisation with the α1-ECD and thus well suited for testing antigen-specific treatments. The animal clinical score, body weight, compound muscle action potential decrement and muscle AChR content were measured. Sera samples taken at various time points after induction were used for autoantibody characterization.

Results

We assessed therapeutic efficacy with different administration routes, doses and time points during disease progression. Our results showed that intravenous treatment with α1-ECD resulted in significantly reduced EAMG symptoms in a dose and time dependent manner. Changes in autoantibody levels and subclasses were detected. Importantly, the effect was long-lasting, in contrast to drugs representing current standard of care for MG.

Conclusions

Restoring immunological tolerance against specific autoantigens by intravenous administration is, therefore, a promising therapeutic approach for MG. Further investigations are underway to elucidate immune mechanisms involved.

Background and Aims

Neuroinflammation and autoantibodies against Aquaporin-4 (AQP4) are highly characteristic for neuromyelitis optica spectrum disorders (NMOSD). Here, we investigate whether novel antigen-specific tolerance-inducing biomolecules that present AQP4-peptide antigens on MHC class Ib-related molecules can induce AQP4-specific regulatory T cells. We further explore whether corresponding surrogate molecules confer protection in murine neuroinflammatory disease models.

Methods

The α3 domain of the human MHC class Ib molecule HLA-G inhibits human T cells via ILT-2 and murine immune cells via PIRB. We generated single chain molecules comprising antigenic peptides, human or murine MHC class I α1-α2 antigen presenting domains, an HLA-G α3 domain and β2-microglobulin (AIM Bios). ELISpot was used to test if these molecules induce antigen-specific tolerogenic CD8⁺ T_reg cells both in human PBMCs in vitro and in mice. The therapeutic potential of AIM Bios was further analyzed in neuroinflammatory experimental autoimmune encephalomyelitis (EAE) mouse models.

Results

Disease-associated AQP4 CD8⁺ epitopes were identified by mass spectrometry and tetramer staining. AIM Bios selectively polarize CD8⁺ T cells cognate for the presented peptide towards CD8⁺CD122⁺ IL-10 secreting T_reg. Such antigen-specific T_reg can also be induced with surrogate molecules in mice in vivo. Here, AIM Bios prevent immune-mediated neuroinflammatory disease symptoms by either targeting autoreactive effector T cells, or by conferring bystander protection via induction of tissue-specific T_reg cells.

Conclusions

AIM Bios induce human AQP4-specific regulatory T cells in vitro and prevent neuroinflammatory disease in animal models. Aquaporin-4-specific AIM Bios may therefore be highly suitable for targeted immunosuppression in neuromyelitis optica spectrum disorders.

Background and Aims

Multiple sclerosis is an autoimmune disease, and oxidative stress (OS) plays an important role in its occurrence and development. In this study, we attempt to investigate the effect of Hydroxyfasudil (HF) on OS in EAE mice and its possible mechanisms.

Methods

BV2 cells were randomly separated into normal control group, LPS group and LPS+HF group. BV2 cells were stimulated by LPS for 24h after HF pretreatment for 2h. C57BL/6 mice were randomly separated into EAE group and HF group. Mice in HF group were intraperitoneally injected with HF from day 3 after immunization. The changes in cell viability of BV2 cells were detected by MTT. The inflammation and demyelination of spinal cords were detected by HE and LFB. The contents of RNS, ROS, MDA, SOD, CAT and GSH-Px were detected by ELISA, and the expressions of Nrf2 and HO-1 were detected by western blot.

Results

No changes in BV2 cells viability were observed when the concentration of HF in 0-15 μg/ml. HF inhibited the clinical scores of EAE mice, improved the inflammation and demyelination of spinal cords, reduced oxidation products ROS, RNS and MDA, increased antioxidant enzymes SOD, CAT and GSH-Px, and increased the expression of Nrf2 and HO-1 in spinal cords of mice.

Conclusions

HF improved the clinical symptoms and related pathological damage of EAE mice, which might be related to the activation of Nrf2/HO-1 signaling pathway by HF to inhibit OS. (Supported by NSF of China, 81473577, 81903596. Ma and Song are corresponding authors).