The present example involves elucidation of the mechanism whereby Leu-Leu OMe kills cytotoxic lymphocytes. MP-depleted lymphocytes were treated with varying concentrations of dipeptide methyl esters as outlined in FIG. Monocyte-enriched populations MP were prepared from glass adherent cells and MP-depleted lymphocytes from the nonadherent cells remaining after incubation in glass Petri dishes and passage through nylon wool columns as detailed in Rosenberg et al.
The condition of the manipulations resulting in the data leading to FIG. Vp ; Ortaldo et al. Therefore, the series of experiments depicted in FIG. A second problem in bone marrow transplantation is the failure of engraftment the transplant does not "take" or is rejected.
Therefore, it was suggested that NK cells, not T cells, mediated the rejection of the parental bone marrow. These inhibitors should provide a useful tool for the study of bacterial and mammalian metalloendopeptidases or dipeptidyl carboxypeptidases and for the assessment of their physiological role.
A variety of diseases have been classified as "autoimmune diseases" because of the widely accepted relief that they are caused by disorders in the immune system which cause immunologic damage to "self".
Irradiated recipient mice transplanted with a mixture of control bone marrow and spleen cells from naive semiallogeneic donors died rapidly from GVHD, whereas the recipients of cells incubated with micro-M Leu-Leu-OMe all survived.
The NK toxicity of both aspartyl phenylalanine methyl ester and beta methyl aspartyl phenylalanine methyl ester was measured as described for the dipeptide methyl esters in Example 7. Therefore, it was suggested that NK cells, not T cells, mediated the rejection of the parental bone marrow.
Most soft-drinks have a pH between 3 and 5, where aspartame is reasonably stable. VpOKT11 Perussia et al. Furthermore, incubation of each of these non-lymphoid cell types with micromolar Leu-Leu-OMe had no discernible effect on subsequent proliferative capacity data not shown.
Vpand interleukin 1 Dempsey et al. An elaboration of the model for the locus of the active site where the side chains of the amino acid derivatives are bound is offered. After lymphokine activation, additional cytotoxic lymphocytes capable of lysing a broad spectrum of tumor cell targets can be generated in in vitro cultures Seeley et al.
The generally accepted lysosomotropic mechanism involved leu-OMe diffusion into cells and into lysosomes, followed by intralysosomal hydrolysis to leucine and methanol. Additional support for this hypothesis was derived from the observation that mice of a strain normally incapable of rejecting bone marrow transplants acquire this ability when they are injected with cloned NK cells.
Inhibition of metalloendopeptidases by 2-mercaptoacetyl-dipeptides. Furthermore, when the D-stereoisomer was present in either position of a dipeptide methyl ester, no toxicity was observed for NK cells FIG.
This suppression should be achieved by treating the recipient with the dipeptide methyl esters of the present invention prior to transplantation. The required dipeptides 1—3 were prepared by coupling of Boc-amino acids, viz. This prediction of effective GVHD prevention has been further supported by experiments described herein.
Thus, it is reasonable that similar mechanisms of cytotoxic lymphocyte damage to liver cells may be occurring, and therefore benefit from therapy with peptide esters or amides of the present invention should also occur in such disease states.
Although yet not as toxically effective as a number of the hydrophobic-type dipeptides in Example 7, the data in Table 2 indicate that a dipeptide methyl ester comprising synthetic hydrophobic lipophilic amino acids may be used to inhibit NK function.
The method would initially comprise the step of identifying a patient with autoimmune disease and would thereafter be similar to that described for the other clinical disorders.
Thus, in a variety of diseases, including primary biliary cirrhosis, systemic lupus erythematosus, rheumatoid arthritis multiple sclerosis, autoimmune hemolytic anemia, etc.
V 70, p ; and Nogaawa et al. The methyl esters of a variety of dipeptides were synthesized and analyzed for the capacity to deplete NK cell function. Leu--OEtL amino acid benzyl esters e. In additional experiments detailed in Table 9, it was noted that synthesis of this TCA precipitable material from Leu-Leu-OMe was not inhibited by a concentration of cycloheximide known to block ribosomal protein synthesis.
The stability when dissolved in water depends markedly on pH. The presently described invention relates to the discovery that peptide esters and amides may be cytotoxic to particular cell types. In contrast to the effect noted with Leu-OMe, the lysosomal inhibitors did not protect NK cells from the action of this product s.Laboratory of Peptide Research and Development, School of Pharmacy, Faculty of Medical Sciences, The University of the West Indies, St.
Augustine, Trinidad & Tobago, West Indies The N-methyl amino acid methyl ester hydrochloride or dipeptide methyl ester ( mol) was dissolved in DMF (25 mL). To. A series of 2-mercaptoacetyl-dipeptides, a potential group of metalloendopeptidase inhibitors, has been synthesized by coupling the N-hydroxysuccinimide ester of S-acetylmercaptoacetic acid.
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An alkyl ester of dipeptide consisting essentially of natural or synthetic L-amino acids with hydrophobic side chains. Preferable amino acids are leucine, phenylalanine valine, isoleucine, alanine, proline, glycine or aspartic acid beta methyl ester. Structure, properties, spectra, suppliers and links for: N-Acetyl-L-phenylalanine, Apr 19, · The NK toxicity of both aspartyl phenylalanine methyl ester and beta methyl aspartyl phenylalanine methyl ester was measured as described for the dipeptide methyl esters in Example 7.Download