GENERATION AND CHARACTERIZATION OF A MICROGLIAL CELL-LINE, MG5, DERIVED FROM A P53-DEFICIENT MOUSE

We have established a cell line cloned from primary-cultured microglia obtained from p53-deficient mice. The cell line, MG5, could be grown in astrocyte-conditioned medium and has been maintained for more than a year MG5 cells are immunocytochemically positive for Mac-1 and F4/80 antibody and express the major histocompatibility complex (MHC) class I antigen, leukocyte function-associated antigen-1, leukocyte common antigen, and intercellular adhesion molecular-1 mRNA. Interferon-gamma enhanced the expression of MHC class II antigen mRNA in MG5 cells. We previously identified a novel calcium-binding protein, Iba1 (ionized calcium-binding adapter molecule 1), which is highly and specifically expressed in cultured microglia. Iba1 protein was also immunocytochemi cally demonstrated in MG5 cells. The cells retained non-specific ester ase activity, 5'-nucleotidase activity, acid phosphatase activity, and phagocytic ability Like primary cultured microglia from wild-type mic e, MG5 cells released nitric oxide in response to lipopolysaccharide, and actively proliferated in the presence of mitogenic factors such as macrophage-colony stimulating factor (M-CSF), granulocyte/macrophage- CSF (GM-CSF), and interleukin-3 (IL-3). Tyrosine-phosphorylation of M- CSF receptor in MG5 cells was induced by the addition of M-CSF or astr ocyte-conditioned medium. These findings indicate that MG5 cells prese rve the morphological, biochemical, and physiological properties of pr imary-cultured microglia well. The MG5 cell line will be a useful tool for studying microglial function. (C) 1997 Wiley-Liss, Inc.