Macrophage cell lines transformed by the malignant histiocytosis sarcoma virus: Increase of CSF receptors suggests a model for transformation

Abstract

The malignant histiocytosis sarcoma virus (MHSV) contains Ha‐v‐ras‐related oncogenic sequences and rapidly transforms myeloid cells in vivo and in vitro. Myeloid cell lines can be derived which do not require growth factor for continued proliferation. We initiated this work to define the process of transformation leading to autonomy of cell growth in transformed myeloid cells. Five established cell lines were examined. All express macrophagespecific cell‐surface antigens and exhibit several other properties typical for mature macrophages. Growth properties, growth factor release, and growth factor receptor presentation were examined: Release of growth factors is not a consistent feature. All..