Sphingosine 1-phosphate Receptor Modulator Research Articles

S812 Hepatic Safety of Ozanimod in Ulcerative Colitis and Relapsing Multiple Sclerosis Phase 3 Trials

Introduction: Ozanimod (OZA) is a sphingosine 1-phosphate (S1P) receptor modulator approved for the treatment of moderately to severely active ulcerative colitis (UC) and relapsing forms of multiple sclerosis (MS) in the United States and European Union. Other S1P receptor modulators have shown substantial elevations in hepatic enzymes. Methods: The impact of OZA on liver function tests was assessed in this safety analysis from phase 3 UC and MS trials. In the 52-week (10-week induction period and 42-week maintenance period), randomized True North (TN) trial, patients (pts) with moderately to severely active UC were treated with placebo (n=216) or OZA 0.92 mg (equivalent to OZA HCl 1 mg) (n=796). In the randomized MS trials (SUNBEAM and RADIANCE), MS pts were treated with interferon beta-1a 30 µg (n=885) or OZA (n=882) for 12 and 24 months, respectively. Hepatic enzymes were assessed at baseline and Weeks 5, 10, 18, 28, 40, and 52 in TN, and at baseline and every 3 months for the MS trials. In the UC and MS trials, enzyme elevations were confirmed with a repeated test within 14 days. Results: Percentages of pts on OZA 0.92 mg with elevations in alanine transaminase (ALT), aspartate aminotransferase (AST), and bilirubin are shown in the Table; < 6% and < 2% of pts had ALT and AST elevations ≥3 x upper limit of normal (ULN), respectively, and < 2% had bilirubin elevations >2 x ULN. Of those with ALT ≥3 x ULN, 86.4% (19/22) of UC pts and 85.4% (41/48) of MS pts recovered to ALT < 3 x ULN within 3 months. Most hepatic treatment-emergent adverse events (TEAEs) were mild to moderate in UC and MS pts. In TN, 3 (0.4%) pts on OZA reported a hepatobiliary disorder TEAE, 1 (0.1%) of whom had hyperbilirubinemia. In the MS trials, 15 (1.7%) pts on OZA 0.92 mg reported a hepatobiliary disorder TEAE, 3 (0.3%) of whom had hyperbilirubinemia. Hepatic-related events leading to discontinuation, which were generally asymptomatic laboratory abnormalities, were reported in 4 (0.5%) UC pts and in 11 (1.2%) MS pts on OZA 0.92 mg. No serious hepatic TEAEs, Hy’s law cases, or severe drug-induced hepatocellular injuries occurred with OZA 0.92 mg in any of the trials. Conclusion: In this analysis of phase 3 UC and MS trials with OZA, elevations of aminotransferases and bilirubin occurring with OZA were infrequent, generally asymptomatic, and transient. These elevations, which generally resolved without study drug discontinuation, did not meet the criteria for Hy’s law or protocol-defined serious AEs. Table 1. - Maximum postbaseline ALT, AST, and bilirubin levels with OZA 0.92 mg Parameter TN (UC)(n=783) Sunbeam/Radiance (MS) (n=878) ALT >1 × ULN 215 (27.5) 373 (42.5) ≥3 × ULN 22 (2.8) 48 (5.5) ≥5 × ULN 8 (1.0) 14 (1.6) AST >1 × ULN 136 (17.4) 185 (21.1) ≥3 × ULN 14 (1.8) 9 (1.0) ≥5 × ULN 5 (0.6) 5 (0.6) Bilirubin >1 × ULN 32 (4.1) 122 (13.9) >2 × ULN 3 (0.4) 14 (1.6) >3 × ULN 1 (0.1) 3 (0.3)

S759 Model-Predicted Lymphocyte Response and Recovery Profiles for the Sphingosine 1-Phosphate Receptor Modulators Ozanimod and Etrasimod

S759 Model-Predicted Lymphocyte Response and Recovery Profiles for the Sphingosine 1-Phosphate Receptor Modulators Ozanimod and Etrasimod

Sphingosine 1-phosphate receptor modulators for the treatment of inflammatory bowel disease and other immune-mediated diseases

Sphingosine 1-phosphate receptor modulators for the treatment of inflammatory bowel disease and other immune-mediated diseases

Siponimod ameliorates metabolic oligodendrocyte injury via the sphingosine-1 phosphate receptor 5

Multiple sclerosis (MS), an autoimmune-driven, inflammatory demyelinating disease of the central nervous system (CNS), causes irreversible accumulation of neurological deficits to a variable extent. Although there are potent disease-modifying agents for its initial relapsing-remitting phase, immunosuppressive therapies show limited efficacy in secondary progressive MS (SPMS). Although modulation of sphingosine-1 phosphate receptors has proven beneficial during SPMS, the underlying mechanisms are poorly understood. In this project, we followed the hypothesis that siponimod, a sphingosine-1 phosphate receptor modulator, exerts protective effects by direct modulation of glia cell function (i.e., either astrocytes, microglia, or oligodendrocytes). To this end, we used the toxin-mediated, nonautoimmune MS animal model of cuprizone (Cup) intoxication. On the histological level, siponimod ameliorated cuprizone-induced oligodendrocyte degeneration, demyelination, and axonal injury. Protective effects were evident as well using GE180 translocator protein 18-kDa (TSPO) imaging with positron emission tomography (PET)/computed tomography (CT) imaging or next generation sequencing (NGS). Siponimod also ameliorated the cuprizone-induced pathologies in Rag1-deficient mice, demonstrating that the protection is independent of T and B cell modulation. Proinflammatory responses in primary mixed astrocytes/microglia cell cultures were not modulated by siponimod, suggesting that other cell types than microglia and astrocytes are targeted. Of note, siponimod completely lost its protective effects in S1pr5-deficient mice, suggesting direct protection of degenerating oligodendrocytes. Our study demonstrates that siponimod exerts protective effects in the brain in a S1PR5-dependent manner. This finding is not just relevant in the context of MS but in other neuropathologies as well, characterized by a degeneration of the axon-myelin unit.

Microglia Contributes to BAF-312 Effects on Blood-Brain Barrier Stability.

Microglia, together with astrocytes and pericytes, cooperate to ensure blood–brain barrier (BBB) stability, modulating endothelial responses to inflammatory insults. Agonists of the sphingosine 1 phosphate (S1P) receptors, such as siponimod (BAF-312), are important pharmacological tools in multiple sclerosis and other inflammatory diseases. Modulation of S1P receptors may result in a reduced inflammatory response and increased BBB stability. An in vitro BBB model was reproduced using human-derived endothelial cells, astrocytes and microglia. Co-cultures were exposed to inflammatory cytokines (TNFα, 10 UI and IFNγ, 5 UI) in the presence of BAF-312 (100 nM), and the BBB properties and microglia role were evaluated. The drug facilitated microglial migration towards endothelial/astrocyte co-cultures, involving the activity of the metalloprotease 2 (MMP2). Microglia actively cooperated with astrocytes in the maintenance of endothelial barrier stability: in the triple co-culture, selective treatment of microglial cells with BAF-312 significantly prevented cytokines’ effects on the endothelial barrier. In conclusion, BAF-312, modulating S1P receptors in microglia, may contribute to the reinforcement of the endothelial barrier at the BBB, suggesting an additional effect of the drug in the treatment of multiple sclerosis.

Sphingosine 1-phosphate signaling in perivascular cells enhances inflammation and fibrosis in the kidney.

Chronic kidney disease (CKD), characterized by sustained inflammation and progressive fibrosis, is highly prevalent and can eventually progress to end-stage kidney disease. However, current treatments to slow CKD progression are limited. Sphingosine 1-phosphate (S1P), a product of sphingolipid catabolism, is a pleiotropic mediator involved in many cellular functions, and drugs targeting S1P signaling have previously been studied particularly for autoimmune diseases. The primary mechanism of most of these drugs is functional antagonism of S1P receptor-1 (S1P1) expressed on lymphocytes and the resultant immunosuppressive effect. Here, we documented the role of local S1P signaling in perivascular cells in the progression of kidney fibrosis using primary kidney perivascular cells and several conditional mouse models. S1P was predominantly produced by sphingosine kinase 2 in kidney perivascular cells and exported via spinster homolog 2 (Spns2). It bound to S1P1 expressed in perivascular cells to enhance production of proinflammatory cytokines/chemokines upon injury, leading to immune cell infiltration and subsequent fibrosis. A small-molecule Spns2 inhibitor blocked S1P transport, resulting in suppression of inflammatory signaling in human and mouse kidney perivascular cells in vitro and amelioration of kidney fibrosis in mice. Our study provides insight into the regulation of inflammation and fibrosis by S1P and demonstrates the potential of Spns2 inhibition as a treatment for CKD and potentially other inflammatory and fibrotic diseases that avoids the adverse events associated with systemic modulation of S1P receptors.

Sphingosine-1-phosphate receptor modulators in stroke treatment.

Sphingosine-1-phosphate (S1P) is a bioactive lysophospholipid that can influence a broad range of biological processes through its binding to five distinct G-protein-coupled receptors. S1P receptor modulators are a new group of immunosuppressive agents currently used in the immunotherapy of multiple sclerosis. Inflammation following stroke can exacerbate neuronal injury. Given that S1P signaling is linked to multiple immune processes, therapies targeting the S1P axis may be suitable for treating stroke. In this review, we outline S1P metabolism and S1P receptors, discuss the mechanisms of action of S1P receptor modulators in lymphocyte migration and their direct action on cells of the central nervous system, and provide a concise summary of the efficacy of S1P receptor modulators in animal studies and clinical trials on treatments for stroke.

Sphingosine 1-Phosphate Modulation in Inflammatory Bowel Diseases: Keeping Lymphocytes Out of the Intestine.

Inflammatory bowel diseases (IBDs) are chronic and disabling conditions that, uncontrolled, lead to irreversible bowel damage and associated comorbidities. Despite the new era of biological therapies, IBDs remain not curative. The treatment purpose is to induce endoscopic remission, reduce the progression of the disease and improve the quality of life. Optimal and early treatment could enable the prevention of their complications. Small molecules, administrated as oral agents, have the capacity of overcoming the limitations of biologic agents (i.e., parenteral administration, rapidity of action and primary and secondary non-responsiveness). Of special interest are results from the use of oral sphingosine 1-phosphate (S1P) receptor modulators (ozanimod, etrasimod, fingolimod and laquinimod), based on S1P activities to target lymphocyte recirculation in the mucosa, acting as immunosuppressive agents. Most S1P modulators are reported to be safe and effective in the treatment of both UC and CD. High and satisfactory rates of clinical remission as well as endoscopic improvement and remission can be achieved with these molecules. Safety alarms remain rather low, although the S1P binding to two of its G protein-coupled receptors, 2 and 3 (S1PR2 and S1PR3), may be associated with cardiovascular risks. Cost-effectiveness studies and head-to-head trials are needed to better define their place in therapy. This review summarizes these emerging data published by PubMed and EMBASE databases and from ongoing clinical trials on the safety and efficacy of selectivity of S1P modulators in the treatment of IBD.

Immune cell subset profiling in multiple sclerosis after fingolimod initiation and continued treatment: The FLUENT study.

BackgroundFingolimod is a sphingosine 1-phosphate receptor modulator approved for relapsing MS. Long-term effects on the immunological profile are not fully understood.ObjectiveInvestigate fingolimod's temporal effects on immune cell subsets, and safety outcomes.MethodsIn FLUENT, a 12-month, prospective, non-randomized, open-label, phase IV study, adult participants received fingolimod 0.5 mg/day. Changes in immune cell subsets, anti-John Cunningham virus (JCV) antibody index, and serum neurofilament levels were assessed.Results165 fingolimod-naive and 217 participants treated for 2–12 years in routine clinical practice were enrolled. Levels of all monitored peripheral lymphocyte subsets were reduced from month 3 in fingolimod-naive participants. Greatest reductions occurred in naive and central memory CD4+ and CD8+ T cells, and in naive and memory B cells. Most lymphocyte subset levels remained stable in the continuous fingolimod group. Components of the innate immune system remained within reference ranges. No increase in JCV seropositivity was observed. No single cellular subset correlated with anti-JCV antibody index at any time point. Neurofilament levels remained within healthy adult reference limits throughout. No opportunistic infections were reported; no new or unexpected safety signals were observed.ConclusionFLUENT provides insights into the utility of immunological profiling to evaluate therapy response and potential infection risk.

Sphingosine-1-Phosphate (S1P) and S1P Signaling Pathway Modulators, from Current Insights to Future Perspectives.

Sphingosine-1-phosphate (S1P) and S1P receptors (S1PR) are bioactive lipid molecules that are ubiquitously expressed in the human body and play an important role in the immune system. S1P-S1PR signaling has been well characterized in immune trafficking and activation in both innate and adaptive immune systems. Despite this knowledge, the full scope in the pathogenesis of autoimmune disorders is not well characterized yet. From the discovery of fingolimod, the first S1P modulator, until siponimod, the new molecule recently approved for the treatment of secondary progressive multiple sclerosis (SPMS), there has been a great advance in understanding the S1P functions and their involvement in immune diseases, including multiple sclerosis (MS). Modulation on S1P is an interesting target for the treatment of various autoimmune disorders. Improved understanding of the mechanism of action of fingolimod has allowed the development of the more selective second-generation S1PR modulators. Subtype 1 of the S1PR (S1PR1) is expressed on the cell surface of lymphocytes, which are known to play a major role in MS pathogenesis. The understanding of S1PR1’s role facilitated the development of pharmacological strategies directed to this target, and theoretically reduced the safety concerns derived from the use of fingolimod. A great advance in the MS treatment was achieved in March 2019 when the Food and Drug Association (FDA) approved Siponimod, for both active secondary progressive MS and relapsing–remitting MS. Siponimod became the first oral disease modifying therapy (DMT) specifically approved for active forms of secondary progressive MS. Additionally, for the treatment of relapsing forms of MS, ozanimod was approved by FDA in March 2020. Currently, there are ongoing trials focused on other new-generation S1PR1 modulators. This review approaches the fundamental aspects of the sphingosine phosphate modulators and their main similarities and differences.

P59 Comparative Efficacy and Safety of Ozanimod and Ponesimod for Relapsing Multiple Sclerosis: A Matching-Adjusted Indirect Comparison

Ozanimod and ponesimod are both sphingosine 1-phosphate receptor modulators approved by the FDA for treatment of relapsing forms of multiple sclerosis (MS). Without head-to-head trials between these 2 treatments, we performed a matching-adjusted indirect comparison (MAIC) of efficacy and safety outcomes between ozanimod and ponesimod for MS.

Response of COVID-19 vaccination in multiple sclerosis patients following disease-modifying therapies: A meta-analysis.

SummaryBackgroundCOVID-19 vaccination is recommended for patients with multiple sclerosis (pwMS), while disease-modifying therapies (DMTs) may influence the efficacy of SARS-CoV-2 vaccines in this population. Thus, we conducted a meta-analysis to evaluate the impact of DMTs on immune response to COVID-19 vaccines in pwMS.MethodsLiterature search from December 1, 2019 to March 31, 2022 was performed in PubMed, MedRxiv, Embase and Cochrane Library. The risk of impaired response to vaccination in pwMS receiving DMTs was estimated in odds ratios (ORs) using random-effects method.FindingsA total of 48 studies comprising 6860 pwMS were included. Overall, pwMS with anti-CD20 (OR=0.02, 95% CI: 0.01-0.03) and sphingosine-1-phosphate receptor modulator (S1PRM) (OR=0.03, 95% CI: 0.01-0.06) treatments had attenuated serologic response after full vaccination compared with those without DMTs. Additionally, pwMS vaccinated within six months since last anti-CD20 therapy were at significantly higher risk of blunted response compared with those receiving anti-CD20 therapy more than six months prior to vaccination (P = 0.001). We found no significant associations between other treatments (including IFN-β, GA, DMF, TERI, NTZ, CLAD, and ALE) and humoral response to SARS-CoV-2 vaccines in pwMS. As for T-cell response, no significant difference was found between pwMS on anti-CD20 and those without DMTs after vaccination, while S1PRM was marginally associated with impaired cellular response (P = 0.03).InterpretationOur findings suggested that routine serological monitoring may be required for pwMS on anti-CD20 and S1PRMs after SARS-CoV-2 vaccination and highlighted the benefits of a booster dose. The effect of cellular response and optimal interval from last anti-CD20 treatment to vaccination should be further addressed.FundingThis study was supported by Natural Science Foundation of Shanghai (21ZR1433000).

Competitive Binding of Ozanimod and Other Sphingosine 1-Phosphate Receptor Modulators at Receptor Subtypes 1 and 5.

Ozanimod, a sphingosine 1-phosphate (S1P) receptor modulator, binds with high affinity selectively to S1P receptor subtypes 1 (S1P1) and 5 (S1P5), and is approved in multiple countries for treating adults with relapsing forms of multiple sclerosis (MS) or moderately to severely active ulcerative colitis (UC). Other S1P receptor modulators have been approved for the treatment of MS or are in clinical development for MS or UC, but it is unknown whether these compounds bind competitively with each other to S1P1 or S1P5. We developed a competitive radioligand binding assay using tritiated ozanimod and demonstrate full displacement of ozanimod by S1P (endogenous ligand), suggesting that ozanimod binds to the S1P1 and S1P5 orthosteric binding sites. S1P receptor modulators FTY720-p, siponimod, etrasimod, ponesimod, KRP-203-p, and amiselimod-p also completely displacing radiolabeled ozanimod; thus, on a macroscopic level, all bind to the same site. Molecular docking studies support these results and predict the binding of each molecule to the orthosteric site of the receptors, creating similar interactions within S1P1 and S1P5. The absolute free energy perturbation method further validated key proposed binding modes. Functional potency tightly aligned with binding affinities across S1P1 and S1P5 and all compounds elicited S1P1-mediated β-arrestin recruitment. Since all the S1P modulators included in this study display similar receptor pharmacology and compete for binding at the same site, they can be considered interchangeable with one another. The choice of any one particular agent should therefore be made on the basis of overall therapeutic profile, and patients can be offered the opportunity to switch S1P medications without the potential concern of additive S1P pharmacology.

Siponimod vs placebo in active secondary progressive multiple sclerosis: a post hoc analysis from the phase 3 EXPAND study

BackgroundSiponimod is a sphingosine 1-phosphate receptor modulator approved for active secondary progressive multiple sclerosis (aSPMS) in most countries; however, phase 3 EXPAND study data are from an SPMS population with/without disease activity. A need exists to characterize efficacy/safety of siponimod in aSPMS.MethodsPost hoc analysis of participants with aSPMS (≥ 1 relapse in 2 years before study and/or ≥ 1 T1 gadolinium-enhancing [Gd +] magnetic resonance imaging [MRI] lesions at baseline) receiving oral siponimod (2 mg/day) or placebo for up to 3 years in EXPAND. Endpoints: 3-month/6-month confirmed disability progression (3mCDP/6mCDP); 3-month confirmed ≥ 20% worsening in Timed 25-Foot Walk (T25FW); 6-month confirmed improvement/worsening in Symbol Digit Modalities Test (SDMT) scores (≥ 4-point change); T2 lesion volume (T2LV) change from baseline; number of T1 Gd + lesions baseline–month 24; number of new/enlarging (N/E) T2 lesions over all visits.ResultsData from 779 participants with aSPMS were analysed. Siponimod reduced risk of 3mCDP/6mCDP vs placebo (by 31%/37%, respectively; p < 0.01); there was no significant effect on T25FW. Siponimod increased likelihood of 6-month confirmed SDMT improvement vs placebo (by 62%; p = 0.007) and reduced risk of 6-month confirmed SDMT worsening (by 27%; p = 0.060). Siponimod was associated with less increase in T2LV (1316.3 vs 13.3 mm3; p < 0.0001), and fewer T1 Gd + and N/E T2 lesions than placebo (85% and 80% reductions, respectively; p < 0.0001).ConclusionsIn aSPMS, siponimod reduced risk of disability progression and was associated with benefits on cognition and MRI outcomes vs placebo.Trial registrationClinicalTrials.gov number: NCT01665144.

Selective Sphingosine 1-Phosphate Receptor 1 Modulation Augments Thrombolysis of Low-Dose Tissue Plasminogen Activator Following Cerebrovascular Thrombosis.

BackgroundResults from our recent study demonstrate that sphingosine-1-phosphate receptor 1 (S1PR1) modulation improves microvascular hemodynamics after cerebrovascular thrombosis. This study was to determine the microvascular hemodynamic effects of a sub-thrombolytic dose of tPA combined with a selective S1PR1 modulator ozanimod in a mouse model of cerebrovascular thrombosis.MethodsMicrovascular circulation in mice was monitored in vivo by two-photon microscopy. Thrombosis was induced in cortical arterioles by laser irradiation. Arteriolar flow velocity was measured by line-scanning following plasma-labeling with fluorescein-dextran.ResultsLaser‐induced thrombosis led to a persistent reduction of flow velocity in cortical arterioles. Sub-thrombolytic dose of tPA along with vehicle control did not improve the flow velocity in cortical arterioles following thrombosis. In contrast, a sub-thrombolytic dose of tPA along with ozanimod dramatically restored flow velocity in cortical arterioles following thrombosis. Ozanimod did not affect coagulation and bleeding time. Notably, ozanimod reduced thrombus volume without altering microvascular lumen diameter. In addition, ozanimod reduced leukocyte components within the thrombus.ConclusionsThese findings demonstrate that the thrombolytic effect of a sub-thrombolytic dose of tPA is markedly enhanced by S1PR1 modulation, implying that S1PR1 modulation may improve the therapeutic benefit of low-dose tPA in patients with acute ischemic stroke.

043 Efficacy of siponimod in secondary progressive multiple sclerosis with active disease: EXPAND study subgroup analysis

BackgroundSiponimod, a selective sphingosine 1-phosphate receptor modulator, demonstrated clini- cally relevant effects in a typical secondary progressive multiple sclerosis (SPMS) population in the Phase 3 EXPAND study, with 21% and 26% reductions in 3- and 6-month confirmed disability progression (CDP) versus placebo.MethodsPost hoc subgroup analysis was performed in patients with active disease (defined as the presence of relapses in 2 years before screening and/or ≥1 T1 gadolinium-enhancing [Gd ] lesion at baseline) to assess the efficacy of siponimod 2mg versus placebo in this population.ResultsThis analysis included 779 SPMS patients with active disease (siponimod [n=516], placebo [n=263]). The proportion of patients with relapse in the 2 years prior to study was 76% and with Gd lesions at baseline 45%. Siponimod significantly reduced 3-month CDP risk by 31% (HR [95% CI]: 0.69 [0.53, 0.91]; p=0.0094) and 6-month CDP risk by 37% (HR [95% CI]: 0.63 [0.47, 0.86], p=0.0040) versus placebo. Reductions in risk of 6 month SDMT worsening, ARR, and MRI endpoints were also seen.ConclusionsIn this subgroup of active SPMS patients from EXPAND, benefits on disability progression were more pronounced with clinically relevant effects across disability progression, cognitive processing speed, and MRI inflammatory disease activity.g.giovannoni@qmul.ac.uk

Sphingosine 1-phosphate receptor-targeted therapeutics in rheumatic diseases.

Sphingosine 1-phosphate (S1P), which acts via G protein-coupled S1P receptors (S1PRs), is a bioactive lipid essential for vascular integrity and lymphocyte trafficking. The S1P-S1PR signalling axis is a key component of the inflammatory response in autoimmune rheumatic diseases. Several drugs that target S1PRs have been approved for the treatment of multiple sclerosis and inflammatory bowel disease and are under clinical testing for patients with systemic lupus erythematosus (SLE). Preclinical studies support the hypothesis that targeting the S1P-S1PR axis would be beneficial to patients with SLE, rheumatoid arthritis (RA) and systemic sclerosis (SSc) by reducing pathological inflammation. Whereas most preclinical research and development efforts are focused on reducing lymphocyte trafficking, protective effects of circulating S1P on endothelial S1PRs, which maintain the vascular barrier and enable blood circulation while dampening leukocyte extravasation, have been largely overlooked. In this Review, we take a holistic view of S1P-S1PR signalling in lymphocyte and vascular pathobiology. We focus on the potential of S1PR modulators for the treatment of SLE, RA and SSc and summarize the rationale, pathobiology and evidence from preclinical models and clinical studies. Improved understanding of S1P pathobiology in autoimmune rheumatic diseases and S1PR therapeutic modulation is anticipated to lead to efficacious and safer management of these diseases.

Comparison of the Safety and Efficacy of Tofacitinib and Fingolimod in TNBS‐Induced Colitis Model in Adult Zebrafish: The Role of Myd88/NF‐κB/TNF‐α Signaling Pathway

Due to the inadequate response, side effects, parenteral route of administration, and immunogenicity, oral targeted small molecules seem to replace monoclonal antibodies in the future management of ulcerative colitis (UC). In order to pave the way for clinical translations of small molecules in UC, for the first time, we compared the efficacy of fingolimod and tofacitinib in preclinical model of colitis, and uncovered another mechanism of action that these medicines may act through.We implicated adult zebrafish to find out its pros/cons, investigated aquatic toxicity of the mentioned compounds, and designed a procedure to evaluate compound's efficacy in adult zebrafish colitis model; hence, facilitating screening of further agents.Tofacitinib and fingolimod were investigated to be in category 1 of Globally Harmonized System (GHS) aquatic toxicity classification with the LC50 of 0.9014 and 0.36 mg/L, respectively, based on the acute toxicity assessment within 96 h.Considering efficacy assessments, colitis was induced through intrarectal administration of 160 mM TNBS for 48 h. Then, animals were exposed to different concentrations of tofacitinib (0.25, 0.57, 0.72, 0.90 mg/L) and fingolimod (0.23, 0.28, 0.36, 0.45 mg/L) for 96 h. Subsequent analyses revealed that TNBS significantly reduced length of villi, number of goblet cells, level of TNF‐α, MyD88, and NF‐κB2, increased thickness of villi and necrosis, and induced histopathological changes, including intestinal edema, submucosal hemorrhage/hyperemia with the presence of inflammatory cells. All the aforementioned parameters were considerably enhanced almost dose‐dependently with both agents, wherein the effect of 0.45 mg/L fingolimod was superior to other groups. As well, there were no signs of hyperemia/hemorrhage in harvested intestinal samples. Resultantly, we revealed that these medications may suppress canonical and non‐canonical NF‐κB pathways through targeting toll‐like receptors and MyD88.Given the better efficacy and multi‐targeted action of fingolimod, it worth to focus on sphingosine‐1 phosphate receptor modulators in clinical trials of UC and compare them with other classes of medications; albeit, their ecotoxicity aspect should not be overlooked.

Abstract 110: The Role Of Sphingosine-1-Phosphate In The Reverse Transendothelial Migration Of Aortic Intimal Myeloid Cells

CD11c + myeloid cells (MCs) reside in the normal aortic arch intima at regions predisposed to atherosclerosis. We showed that reverse transendothelial migration (RTM) of these intimal MCs into the arterial circulation is a protective immune response. RTM is triggered by systemic stimulation of cytokine and toll-like receptors (TLRs), e.g., TLR4 by lipopolysaccharide (LPS), and is inhibited by hypercholesterolemia and associated intimal MC lipid accumulation. We hypothesize that signaling by sphingosine-1-phosphate (S1P) and its receptors (S1PRs) is required for RTM of intimal MCs following systemic stimulation of TLRs, analogous to its role in immune cell trafficking in lymphoid tissues. In the lesser curvature of the aortic arch of wild type C57BL/6 mice, LPS induced the expression of S1P receptors 1 &amp; 3, and sphingosine kinase 1 (SphK1). FTY720, a broad-spectrum S1P receptor modulator, blocked LPS-induced RTM, as determined by the enumeration of CD11c+ MCs by en face immunoconfocal microscopy. S1PR1 or S1PR3 inhibitors blocked RTM in a partial and additive manner, suggesting a role for both S1P receptors in intimal MC migration. Initial experiments show that Cre-mediated deletion of S1PR1 in myeloid cells partially blocks LPS-induced RTM, suggesting that myeloid-specific S1PR1 signaling is implicated in the migratory process. Furthermore, global loss or hematopoietic deficiency of SPHK1 reduced the abundance of CD11c+ MCs in the aortic intima, suggesting an additional role for myeloid S1P production in the homeostatic maintenance of resident aortic immune cells. Cre-mediated deletion of S1PR1 in endothelial cells also reduced the abundance of intimal MCs, providing further evidence that S1P signaling in the intima is important in maintaining the intimal MC population. Thus, functional and expression studies suggest that S1P signaling plays a role in both the maintenance of resident intimal MCs and LPS-induced RTM.

Is humoral and cellular response to SARS-CoV-2 vaccine modified by DMT in patients with multiple sclerosis and other autoimmune diseases?

Background: The effect of disease-modifying therapies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine response is unclear. Objectives: We aim to determine the immunological responses to SARS-CoV-2 in multiple sclerosis (MS) and anti-CD20-treated patients with other autoimmune diseases (AID). Methods: Humoral and cellular responses we determined before and 30-90 days after vaccination in patients with MS and anti-CD20-treated patients with other AID in two Catalan centers. Results: 457 patients were enrolled. Findings showed that humoral response decreased under anti-CD20s or sphingosine 1-phosphate receptor modulators (S1PRM) and with longer treatment duration and increased after 4.5 months from the last anti-CD20 infusion. Cellular response decreased in S1PRM-treated. Patients on anti-CD20 can present cellular responses even in the absence of antibodies. Conclusion: Anti-CD20s and S1PRM modify the immunological responses to SARS-CoV-2 vaccines.