Apyrogenic synthetic desmuramyldipeptide, LK-409, with immunomodulatory properties.

The synthesis and some immunological characteristics of a new desmuramyl dipeptide 7-oxooctanoyl-L-alanyl-D-isoglutamine (LK-409) are presented. The effects of this compound were compared with those of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP). The influence of LK-409 on the number of B and T cells in spleen and the number of peritoneal macrophages was studied; Jerne's plaque forming cells assay was performed to monitor the effect of B cell differentiation. The blast transformation of T cells stimulated with concanavalin A was used to detect the influences on T lymphocytes. The activation of macrophages was studied as well. In contrast to MDP, LK-409 was apyrogenic in the doses applied but had similar immunomodulatory properties. Tested immunological properties and the absence of pyrogenicity and low toxicity make LK-409 a candidate for an immunomodulatory drug and a model molecule suitable for studying and understanding the dual activity of the MDP and its analogues.