L-Leucyl-L-Leucine methyl ester (hydrochloride)

L-Leucyl-L-Leucine methyl ester (LLME) is a lysosomal condensation product that has been reported to be cytotoxic towards natural killer cells and CD4⁺ and CD8⁺ T lymphocytes without affecting helper T cells and B cells. It has also been shown to induce death of monocytes, polymorphonuclear leukocytes, and myeloid tumor cells. Upon entry into cells via receptor-mediated endocytosis, LLME undergoes a condensation process catalyzed by dipeptidyl peptidase I (DPPI) in lysosomes. This condensation leads to lysosomal rupture and DNA fragmentation in DPPI-expressing immune cells such as cytotoxic T cells and natural killer cells.

H-Leu-leu-OMe HCl

[1] M OHLIN. The effect of leucyl-leucine methyl ester on proliferation and Ig secretion of EBV-transformed human B lymphocytes.[J]. Immunology, 1989, 66 4: 485-490.
[2] D L THIELE  P E L. Mechanism of L-leucyl-L-leucine methyl ester-mediated killing of cytotoxic lymphocytes: dependence on a lysosomal thiol protease, dipeptidyl peptidase I, that is enriched in these cells.[J]. Proceedings of the National Academy of Sciences of the United States of America, 1990, 87 1: 83-87. DOI: 10.1073/pnas.87.1.83