Kinoids: a family of immunogens for active anticytokine immunotherapy applied to autoimmune diseases and cancer.

The complex homeostasis of tissues is coordinated by the cytokine network and imbalances in this network may result in chronic immune disorders. Key specific cytokines, such as TNF-alpha, IFN-alpha, IL-4 or VEGF have been demonstrated to be overproduced or abnormally released in the microenvironment of pathologic tissues. These findings have opened up the way to passive immunotherapy with anticytokine monoclonal antibodies. Even though passive immunotherapy has proved to be efficient, it is hampered by specific limitations. The discovery of a family of immunogens, the kinoids, consisting of inactivated cytokine derivatives, has led some to propose them for active immunotherapy as an alternative to passive immunotherapy. This review focuses on kinoids - on their validation in experimental mouse models and ongoing clinical trials. The advantages offered by this active immune therapy in terms of efficacy, safety and patient compliance will be stressed.

Determination of plasma membrane fluidity with a fluorescent analogue of sphingomyelin by FRAP measurement using a standard confocal microscope.

Membrane perturbing effects have been described in neurodegenerative process like Alzheimer's disease and prion disorders. For example, non fibrillar amyloid-beta peptides (Abeta) implicated in Alzheimer's disease may exert its toxicity via membrane perturbation. Membrane organisation can be evaluated by its influence on lateral diffusion of lipids, which itself can be measured by FRAP (fluorescence recovery after photobleaching). We used this technique to study the effects of Abeta on membrane fluidity (Pillot et al., manuscript in preparation). We propose here a simple adaptation of FRAP using standard confocal laser scanning microscopy (CLSM). As a test experiment, we analysed the lateral diffusion of a fluorescent analogue of sphingomyelin and were able to demonstrate its increase upon cholesterol depletion induced by methyl-beta-cyclodextrin (cdx).

Apoptotic neuronal cell death induced by the non-fibrillar amyloid-beta peptide proceeds through an early reactive oxygen species-dependent cytoskeleton perturbation.

In the present study, we have determined the nature and the kinetics of the cellular events triggered by the exposure of cells to non-fibrillar amyloid-beta peptide (A beta). When cortical neurons were treated with low concentrations of soluble A beta (1-40), an early reactive oxygen species (ROS)-dependent cytoskeleton disruption precedes caspase activation. Indeed, caspase activation and neuronal cell death were prevented by the microtubule-stabilizing drug taxol. A perturbation of the microtubule network was noticeable after being exposed to A beta for 1 h, as revealed by electron microscopy and immunocytochemistry. Microtubule disruption and neuronal cell death induced by A beta were inhibited in the presence of antioxidant molecules, such as probucol. These data highlight the critical role of ROS production in A beta-mediated cytoskeleton disruption and neuronal cell death. Finally, using FRAP (fluorescence recovery after photo bleaching) analysis, we observed a time-dependent biphasic modification of plasma membrane fluidity, as early as microtubule disorganization. Interestingly, molecules that inhibited neurotubule perturbation and cell death did not affect the membrane destabilizing properties of A beta, suggesting that the lipid phase of the plasma membrane might represent the earliest target for A beta. Altogether our results convey the idea that upon interaction with the plasma membrane, the non-fibrillar A beta induces a rapid ROS-dependent disorganization of the cytoskeleton, which results in apoptosis.