T cell receptor recognizing myelin basic protein–major histocompatibility complex class II complex (TCR-MBP-MHC II (not standardized—most literature refers to TCR with MBP specificity and its MHC II restriction by the clone name, e.g., 3A6 or Ob.1A12[1][2][4][3]))

The T cell receptor recognizing MBP–MHC II complex is a surface receptor on CD4+ T cells that binds specifically to fragments of myelin basic protein (MBP) presented by major histocompatibility complex class II molecules such as HLA-DR2a or HLA-DR4[1][2][3][4]. These MBP-reactive TCRs (e.g., clone 3A6, Ob.1A12) are implicated in the pathogenesis of multiple sclerosis, mediating self-reactive autoimmune responses in the central nervous system[1][2][4]. Structurally, the TCR binds diagonally across the peptide–MHC II complex, primarily recognizing the N-terminal portion of MBP and utilizing its variable regions for specificity[1][2][3][4][5][7]. The autoimmune TCR–MBP–MHC II complex displays low affinity and unique docking geometry, which may confer degeneracy and cross-reactivity, posing challenges for therapy[1][3]. Therapeutic strategies are experimental and aim to modulate the immune response by targeting this interaction or its downstream signaling.[1][2][3][4][7]

Other names

MBP-reactive T cell receptorMBP-specific TCRautoimmune TCR3A6 TCROb.1A12 TCR

Antagonism or modulation of TCR–peptide–MHC II interaction (e.g., altered peptide ligands reducing pathogenic T cell activation)[1][2][3]; Blockade of TCR signaling pathway[7]