Cell-Cell Signalling

The concept of cellular cooperation has long been recognized as being fundamental in several physio-pathological systems such as: 1) In immunology, B-cells require interaction with T-cells to induce antibody responses. 2) The development of atherosclerotic processes involves interactions between blood cells and vascular cells. 3) Inflammatory reactions necessitate a cooperation among various cell types. 4) Tumor cell metastases are governed by an inter-relation of malignant cells with blood platelets, leukocytes, red blood cells ... followed by interactions with vascular endothelium. Although it seems reasonable to assume that cellular cooperation needs cell-cell signalling in the initiation and/or amplification of such processes, little is known about the biochemical nature of these events. For example, cell-cell recognition can be explained by membrane interactions such as between glycoproteins (or glycoproteins and structural macromolecules) followed by metabolic events of one cell that can turn on or off an activation of neighbouring cells. In this respect, autacoids (e.g., icosanoids) may provide valuable clues for cell-cell signalling.