T cell receptor on Glatiramer acetate-reactive T cells (TCR (GA-reactive))

The T cell receptor (TCR) on Glatiramer acetate (GA)-reactive T cells is the primary molecular interface for the immunomodulatory drug Glatiramer acetate, a first-line treatment for relapsing-remitting multiple sclerosis (RRMS) (FDA, 2023). GA is a synthetic random polymer of four amino acids designed to mimic Myelin Basic Protein (MBP), a major autoantigen in the central nervous system. Upon administration, GA competes with MBP for binding to MHC class II molecules on antigen-presenting cells and interacts with the TCR as an altered peptide ligand (Neuhaus et al., 2001). This interaction triggers the expansion of GA-specific T cells and promotes a functional shift from a pro-inflammatory Th1 phenotype to an anti-inflammatory Th2 or Th3 phenotype (Schrempf & Ziemssen, 2007). These GA-reactive T cells are capable of crossing the blood-brain barrier and entering the central nervous system, where they recognize myelin antigens through TCR cross-reactivity. Once activated in the CNS, these cells secrete anti-inflammatory cytokines such as IL-4, IL-10, and TGF-beta, a process known as bystander suppression that dampens the local autoimmune response (Aharoni et al., 2003). Consequently, the TCR on these specific T cells is central to the drug's ability to reduce the frequency of clinical relapses and the accumulation of physical disability in MS patients.

Other names

TCR on Copaxone-reactive T cellsGlatiramer acetate-specific T cell receptorGA-specific TCRT-cell receptor on GA-specific Th2 cells

Glatiramer acetate acts as an altered peptide ligand (APL) that binds to MHC class II molecules and is recognized by the T cell receptor on GA-reactive T cells, inducing a phenotypic shift from pro-inflammatory Th1 cells to anti-inflammatory Th2/Th3 regulatory cells (Schrempf & Ziemssen, 2007; Neuhaus et al., 2001).