Novel accurate therapy for Multiple Sclerosis: Optimization of antisense oligonucleotides delivery and functionality in primary T cells

PROJECT SUMMARY Multiple SclerosisMSis the most common neurological disease of early adulthood and is mediated by autoimmune mechanisms that lead to demyelination and neuronal damage in the central nervous systemresulting in progressive neurological dysfunctionThere is no cure for the disease and current treatments focus on preventing future immunological attacksmainly by suppressing the immune systemThis leads to adverse side effects that are often severe or fatalAccordinglythere is a clear unmet need for the development of effective and well tolerated therapies to arrest MS developmentThis has been challenging because MS has multiple etiologies and the molecular mechanisms underlying these etiologies are not well understoodWe uncovered the molecular underpinnings of an MS etiology and hope this knowledge will translate into an accurate therapy for MSThis etiology is associated with the interleukinreceptorIL Rgenewhich encodes a cell surface receptor in T cellshereafter referred to as mIL Rthat plays a central role in the homeostasis of T cellsWe previously identified the genetic variant rswithin exonof IL R to be strongly associated with increased MS riskand showed the risk allele of this variant increases exclusion of the alternative exonleading to higher expression of mRNAs encoding a secreted form of the receptorsIL Rand elevated levels of circulating sIL RThis has important implications in the development of MS because sIL R has been shown to aggravate the progression and severity of the disease in the Experimental Autoimmune EncephalomyelitisEAEmouse model of MSFurther supporting thiselevated levels of sIL R have been reported in patients of several autoimmune diseases including MSType I diabetesRheumatoid arthritis and Systemic lupus erythematosusGiven that sIL R is produced by exclusion of exonduring alternative splicing of IL R RNAswe developed a novel biologic druga splicing modulating antisense oligonucleotideSM ASOthat corrects splicing of IL R exonand restores normal expression of IL R protein isoformsOur approach represents a major improvement over current MS therapies in that by correcting IL R splicingit diminishes expression of the pathogenic sIL R isoformwithout reducing expression of the mIL RThis is important because mIL R function is vital for proper immune function and its disruption leads to immunodeficiencyThus our biologic drugunlike current MS drugswill not cause immunosuppressionBecause IL R expression is mostly restricted to T cellsthese are the major producers of sIL R and thus the main target of our IL R SM ASOsAlthough SM ASOs have been shown to modulate RNA splicing decisions in many cell types in vitro and in vivoe gFDA approved Spinrazathe delivery and functionality of SM ASOs in T cells have not been thoroughly examinedand represents the major hurdle to expand the use of SM ASOs for treatment of immunological disorders and immunotherapiesHerewe address this obstacle by testing the influence of diverse chemical modifications on the efficiency of delivery and activity of ASOs in primary T cells PROJECT NARRATIVE Multiple SclerosisMSis a demyelinating autoimmune disorder of the central nervous system that causes progressive neurological dysfunction and disability in young adultsand for which there are no curative and safe treatmentsTo address this unmet need we have developed a novelbiological therapy that bypasses the broad immunosuppressive mechanisms of current drugsand thus provide an effective yet safer treatment for MS patientsThe research proposed here aims to optimize the delivery and functionality of this biological drug in primary T cellsthereby addressing a major potential hurdle for this therapy