Lipophilic muramyl dipeptide-induced changes in electron microscopic morphology and phagocytic function of murine macrophages.
The capacity of a lipophilic derivative of synthetic muramyl dipeptide (MDP), B30-MDP, to induce morphological changes and functional alterations in the activity of resident peritoneal macrophages was studied. Macrophages incubated in vitro for 24 h with B30-MDP, but not with MDP or medium, showed rounding and extensive ruffling of the cell surface when examined by scanning electron microscopy. Transmission electron microscopy of B30-MDP-treated macrophages revealed the development of large cytoplasmic vacuoles. These structural changes did not affect the viability of macrophages. The Fc receptor-mediated phagocytosis of 51Cr-labeled sheep red blood cells by adherent macrophages incubated with a high dose of MDP showed a modest response whereas even low doses of B30-MDP greatly enhanced the phagocytic activity. Adherent macrophages incubated with B30-MDP generated elevated levels of luminol-dependent chemiluminescence in response to stimulation by zymosan.
D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008264:Macrophages / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D010587:Phagocytosis / Q000187:drug effects; D011961:Receptors, Fc / Q000187:drug effects / Q000502:physiology
D011961:Receptors, Fc; D000119:Acetylmuramyl-Alanyl-Isoglutamine; C044706:B 30-muramyl dipeptide