title: A murine macrophage cell line, immortalized by v-raf and v-myc oncogenes, exhibits normal macrophage functions.
abstract: In vitro immortalized cell lines with the morphology and phenotype of mature macrophages (M phi) have been generated by infecting freshly isolated bone marrow cells from C3H/HeJ mice with a recombinant retrovirus carrying v-raf and v-myc oncogenes. All of the clones obtained had M phi-like phenotypes, and one such clone, GG2EE, has been compared to normal M phi to ascertain the effects of immortalization on the expression of the biological functions of the lines. GG2EE cells expressed cytotoxic activity against L5178Y, P815 or RL male 1 target cells in response to stimulation with interferon-gamma (IFN-gamma) and heat-killed Listeria monocytogenes; in contrast, they failed to kill YAC-1 target cells. GG2EE cells did not constitutively express I-A or I-E antigens; nevertheless, I region-coded antigens could be induced by IFN-gamma treatment. GG2EE cells produced interleukin 1 upon stimulation with a T cell-derived lymphokine; they were weakly phagocytic, yet became highly phagocytic following IFN-gamma treatment. Since c-fos mRNA is augmented in peritoneal exudate M phi by protein kinase C activators but not by IFN-gamma, we evaluated the effects of calcium ionophore, phorbol myristate acetate, L-alpha-1-oleoyl-2-acetoyl-sn-3 glycerol (OAG) and IFN-gamma on the levels of c-fos mRNA in GG2EE cells. We found that calcium ionophore, PMA and OAG stimulation enhanced the expression of c-fos mRNA, but IFN-gamma treatment did not. The kinetics of c-fos induction in GG2EE cells were also comparable to those observed in peritoneal exudate M phi. Overall, the GG2EE cell line has the same biological properties as normal tissue M phi. Because it is capable of both constitutive and inducible M phi-like functions, this cell line provides a valuable tool for studying the molecular mechanisms controlling induction and/or expression of biological activities in M phi. It is striking that a cell line immortalized in vitro by two oncogenes, v-raf and v-myc, behaves, according to the criteria mentioned above, like a normal M phi population.
mesh_terms: D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral; D003602:Cytotoxicity, Immunologic; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000096:biosynthesis; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D008809:Mice, Inbred C3H; D009857:Oncogenes; D010587:Phagocytosis; D010641:Phenotype; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D000949:Histocompatibility Antigens Class II; D007375:Interleukin-1; D012333:RNA, Messenger; D007371:Interferon-gamma