g(m1)-ganglioside and Leukemia--Lymphoid

The raft marker GM1 is expressed at very low levels at the plasma membrane of resting T cells (GM1dull). In vitro T-cell activation induces synthesis of this lipid, which is then expressed at very high levels (GM1bright) at the membrane of activated/effector cells. By flow cytometry and confocal microscopy, we analyzed the expression and organization of GM1 in a series of 15 patients with CD3+ lymphoproliferative disease of granular lymphocytes (LDGL). We found that GM1bright GL were detectable in fresh blood samples obtained in all LDGL patients, although the range of brightly stained cells was extremely variable. This distinctive in vivo pattern has never been shown in T lymphocytes from healthy individuals or in patients with different chronic T or B lymphoproliferative disorders or active infectious diseases. The low number of cycling cells detected in LDGL patients was always included within the GM1bright GL population. Interestingly, GM1bright GL were demonstrated to contain a higher amount of IFN-gamma as compared to GM1dull GL. These findings allow to distinguish subsets of GL at different levels of activation within the monoclonal CD3+ population. The GM1bright GL subset is likely to be responsible for the renewing of GL and thus for maintaining chronic proliferation.

Topics: Aged; Antigens, CD; Biomarkers; CD3 Complex; Female; Flow Cytometry; G(M1) Ganglioside; Humans; Killer Cells, Natural; Leukemia, Lymphoid; Male; Membrane Microdomains; Microscopy, Confocal; Middle Aged; T-Lymphocytes; Up-Regulation

Topics: Adult; Aged; Animals; Antibodies, Monoclonal; Cell Separation; Female; Flow Cytometry; G(M1) Ganglioside; Gangliosides; Humans; Leukemia; Leukemia, Lymphoid; Male; Mice; Middle Aged; Phenotype; Receptors, Antigen, T-Cell; T-Lymphocytes

Topics: Adolescent; Adult; Cell Membrane; Child; Child, Preschool; Chromatography, Liquid; Fluorescent Antibody Technique; G(M1) Ganglioside; Gangliosides; Humans; Infant; Leukemia, Lymphoid

Topics: Adolescent; Adult; Cell Membrane; Child; Child, Preschool; Female; Fluorescent Antibody Technique; G(M1) Ganglioside; Glycosphingolipids; Humans; Immune Sera; Infant; Leukemia, Lymphoid; Lymphocytes; Male; Middle Aged; Prednisolone; Staining and Labeling; Vincristine

Binding of purified cholera toxin to cell surface receptors has been visualized by an indirect immunofluorescence procedure. Normal nucleated cells from blood, bone marrow and lymphoid tissues, express these receptors with the possible exception of erythroid precursors. Cells from patients with chronic lymphoid or myeloid leukaemias have a normal receptor expression but acute leukaemic cells showed a marked deficiency in cholera toxin binding. Insertion of purified Gm ganglioside into membranes of acute leukaemic cells provided cellular binding sites for the toxin.

Topics: Bacterial Toxins; Binding Sites, Antibody; Fluorescent Antibody Technique; G(M1) Ganglioside; Glycosphingolipids; Humans; Leukemia, Lymphoid; Leukemia, Myeloid; Lymphocyte Activation; Neuraminidase; Receptors, Drug; Vibrio cholerae

Cell surface binding fluorescent ligands have been used to distinguish between different types of leukaemic cells and between leukaemic cells and their presumed normal counterparts or progenitors. Binding of these probes was evaluated using the Fluorescence Activated Cell Sorter (FACS) which provides both rapid, objective and quantitative recording of fluorescent signals from individual cells plus physical separation of cells of particular interest. Binding sites for cholera toxin (monosialoganglioside GM1) were found to be normally expressed in chronic leukaemias but greatly diminished or absent in acute leukaemias irrespective of their morphological type. Antibodies specific for the common form of acute lymphoblastic leukaemia (ALL, non-T, non-B) have been produced in rabbits. After extensive absorption and testing these were shown to define a cell surface antigen of non-T, non-B type ALLs. The antigen is absent from other leukaemias with two interesting exceptions--the majority of acute undifferentiated leukaemias express the antigen as do a proportion of chronic granulocytic leukaemias in blast crisis relapse. The anti-ALL antibodies can therefore be used to distinguish different leukaemias and, more significantly, can identify the existence of relatively rare leukaemic cells in the blood of untreated patients and the marrow of treated patients considered to be in remission.

Topics: Antibodies, Neoplasm; Binding Sites; Blood Cells; Cell Membrane; Cell Separation; Cross Reactions; Enterotoxins; Fluorescent Antibody Technique; Fluorescent Dyes; G(M1) Ganglioside; Humans; Leukemia; Leukemia, Lymphoid; Remission, Spontaneous; Vibrio cholerae