T-cell antigens in pediatric-onset multiple sclerosis: A unique window into early disease mechanisms

Abstract

Abstract Multiple sclerosis (MS) involves immune attacks on the CNS, leading to demyelination, axonal injury and increasing neurological dysfunction. Though T cells are implicated, the particular subsets and their antigenic targets remain unknown. In adult-onset MS, distinguishing immune responses that are consequences of, rather than cause of, injury, is difficult. In contrast, pediatric-onset MS offers an early window into disease mechanisms given the narrower gap from biological onset. We aim to identify and characterize disease-relevant antigen-specific effector T cell responses to traditional and novel antigenic targets involved early in the MS disease process. Our group has implicated target antigens and T cell subsets in pediatric-onset MS, by following patients from time of an initial presentation with acquired demyelinating syndrome and comparing those confirmed to have MS with those who remain monophasic. A CSF proteomic study implicated novel axo-glial apparatus molecules as early injury targets, rather than traditional compact myelin antigens. A series of multiparameter flow-cytometry panels applied to pediatric peripheral blood mononuclear cells (PBMC) revealed that MS children harbor abnormally increased frequencies and pro-inflammatory cytokine responses of particular effector T cell subsets compared to controls. We will develop assays, initially in fresh PBMC samples from adult MS and controls, then miniaturize the approach and validate it for use in the small numbers of available cryopreserved pediatric PBMC samples to quantify antigen-specific responses including proliferation and cytokine profiles of distinct disease-implicated T cell subsets to both traditionally and newly implicated antigens.