Modulation of CALLA and HLA-DR on a non T non B leukemic cell line by lipid treatment.

The relationship between membrane lipid fluidity and expression of HLA-DR and cALL (CALLA) antigens was studied in a human non T non B acute lymphoblastic leukemia cell line (Reh). The membrane fluidity was modulated by treatment with cholesteryl hemisuccinate or phospholipids (e.g. egg lecithin) and monitored by fluorescence polarization. HLA-DR and CALLA expression was measured in an indirect immunofluorescence test with a Fluorescence Activated Cell Sorter (FACS 440), on 24, 48, 72 and 96 hour-cultured cells. Significant antigenic modulation was obtained with cholesteryl hemisuccinate treatment on 48 hour-cells where a slight increase in HLA-DR and a marked decrease in CALLA were observed. In contrast no antigenic modification was observed on lecithin-treated cells.