An Undifferentiated Variant Derived From the Human Acute Myelogenous Leukemia Cell Line ( KG - i )

A variant subline (KG-la) of the human acute myelogenous leukemia (AML) cell line (KG-i ) has been isolated. The cells retain the same constitutive markers as the parent line, including HIA antigens, isoenzymes, and karyotype. The cells from the subline are morphologically and histochemically undifferentiated blast cells. while the parent cells and several of its clones are at the myeloblast and promyelocyte stages of development. The variant cells do not respond to colonystimulating factor (CSF). and they do not express the human Ia antigen. nor a recently characterized AML antigen. The parent KG-i cells are stimulated to proliferate in the presence of CSF and the cells express the Ia and AML antigen. Variant AMI cell lines. such as KG-i a. will be useful in vitro models for investigating cellular response to CSF and for studying antigen expression in leukemic cells.