Frequency of circulating autoreactive T cells committed to myelin determinants in relapsing–remitting multiple sclerosis patients

Multiple sclerosis (MS) is considered as an autoimmune disease in which T cell reactivity to self-antigens expressed in the brain, particularly myelin antigens, plays a pivotal role. Various myelin-derived peptides, including peptides of myelin basic protein (MBP), proteolipid protein (PLP) and myelin oligodendrocyte glycoprotein (MOG) have been studied as putative target in MS. However, CD4+ and CD8+ T cells recognizing autoantigens from brain have been detected in the blood of MS patients as well as the blood of normal individuals. Here we review and discuss studies focused on the assessment of the frequency of autoreactive T cells responding to a given antigen using different assays including LDA, IFNγ-ELISPOT and TRAP (T cell Recognition of Antigen Presenting Cells by Protein transfer) in MS.

► The frequency of myelin reactive T cells has been largely investigated in MS.
► Both normal and increased frequencies have been reported.
► Studies are difficult to compare because of heterogeneity of patients and protocols.
► The TRAP method based on the trogocytosis phenomenon, is a sensitive method.
► The TRAP method shows an increased frequency of autoreactive T cells.