Influence of glutamine on macrophage functions in vitro

In contrast to lymphocytes, which are rapidly dividing cells, macrophages are terminally differentiated cells that have lost their ability to divide. However, they remain very active cells, characterized by high rates of phagocytosis, protein secretion and membrane recycling. The level of cell surface expression of various molecules involved in phagocytosis and in antigen presentation (major histocompatibility complex (MHC) II) on human blood monocytes is influenced by the concentration of glutamine in which the cells are cultured (Spittler et a¡., 1995, 1997). This is associated with increased function (i.e. increased phagocytosis of immunoglobulin (Ig) G or complement opsonized particles and increased antigen presentation) with increasing glutamine availability (Spittler et a¡., 1995, 1997). Glutamine availability influenced the phagocytic uptake of unopsonized yeast-cell walls (Parry-Billings et a¡., 1990a) and of opsonized sheep red blood cells (Wallace and Keast, 1992) by incubated murine macrophages. The dipeptide alanyl-glutamine can replace glutamine to support in vitro phagocytosis by rat macrophages (Kweon et a¡., 1991).

0 0

Post a comment