Line Activity of Ganglioside GM1 Regulates the Raft Size Distribution in a Cholesterol-Dependent Manner.

Liquid-ordered lipid domains, also called rafts, are assumed to be important players in different cellular processes, mainly signal transduction and membrane trafficking. They are thicker than the disordered part of the membrane and are thought to form to compensate for the hydrophobic mismatch between transmembrane proteins and the lipid environment. Despite the existence of such structures in vivo still being an open question, they are observed in model systems of multicomponent lipid bilayers.

Ganglioside GD2 in reception and transduction of cell death signal in tumor cells.

Background: Ganglioside GD2 is expressed on plasma membranes of various types of malignant cells. One of the most promising approaches for cancer immunotherapy is the treatment with monoclonal antibodies recognizing tumor-associated markers such as ganglioside GD2. It is considered that major mechanisms of anticancer activity of anti-GD2 antibodies are complement-dependent cytotoxicity and/or antibody-mediated cellular cytotoxicity.

Preparation of Fab-fragments of GD2-specific antibodies and analysis of their antitumor activity in vitro.

Monoclonal antibodies ME361 specific to ganglioside GD2 were isolated from the conditioned medium of hybridoma HB9326 and mouse ascitic fluid by the method of affinity chromatography; their Fab-fragments were obtained by proteolytic cleavage with papain. Evaluation of Fab-fragment specificity by flow cytometry and dot-blot analysis showed that binding effectiveness of fragments with antigens was close to that for the full-length molecule of antigen. It was shown that Fab-fragments and whole antibodies ME361 dose-dependently inhibit the proliferation of cells of mice T-lymphoma EL-4, and induce apoptosis of these cells 24 h after incubation.

Clustered carbohydrates as a target for natural killer cells: a model system.

Membrane-associated oligosaccharides are known to take part in interactions between natural killer (NK) cells and their targets and modulate NK cell activity. A model system was therefore developed using synthetic glycoconjugates as tools to modify the carbohydrate pattern on NK target cell surfaces. NK cells were then assessed for function in response to synthetic glycoconjugates, using both cytolysis-associated caspase 6 activation measured by flow cytometry and IFN-gamma production.