[Leu144, Arg147]-PLP (139-151) (trifluoroacetate salt)

[Leu¹⁴⁴,Arg¹⁴⁷]-PLP (139-151) is a mutant peptide fragment of myelin proteolipid protein (PLP) containing tryptophan-to-leucine and histidine-to-arginine substitutions at positions 144 and 147, respectively.¹ Immunization with [Leu¹⁴⁴, Arg¹⁴⁷]-PLP (139-151) (50 µg) emulsified in complete Freund’s adjuvant (CFA) increases spleen levels of IL-4 in mice. It inhibits Th1 cell activation in vitro but not in vivo, where it induces the generation of regulatory T cells.² Preimmunization with [Leu¹⁴⁴, Arg¹⁴⁷]-PLP (139-151) delays the onset of experimental autoimmune encephalomyelitis (EAE) induced by the encephalitogenic peptides PLP (178-191), myelin oligodendrocyte protein (MOG) (92-106), or myelin basic protein (MBP) in mice.