[Leu144,Arg147]-PLP (139-151) is a modified peptide fragment derived from myelin proteolipid protein (PLP), where leucine and arginine have replaced tryptophan and histidine at positions 144 and 147, respectively. This mutant also functions as a T cell receptor (TCR) antagonist, inhibiting the activation of encephalitogenic Th1 clones in vitro. Additionally, [Leu144,Arg147]-PLP (139-151) can impede the progression of experimental autoimmune encephalomyelitis (EAE) .