Possible Cell - Cell Interaction Mechanism

Cell-cell interaction is a basic topic in biological sciences. In embryogenesis, a largely unsolved problem is the means by which cell-cell recognition, necessary for the build up of a normal tissue, is mediated (1). Under pathological conditions this hitherto unrevealed mechanism of physiological interactions seems to be lost. In immunology numerous phenomena are based on cell-cell interactions. Thus, it is, for instance, well accepted that cell cooperation is required for the induction of an antibody response in B cells (2), as well as for the sensitization of T cells (3). In addition, the action of activated T cells on target cells is obviously a cell-cell interaction phenomenon (4). Macrophages are an essential participant in some of these interactions (5). In this paper we want to outline in detail some mechanisms by which complement components might play a role in these cell-cell interaction phenomena. It will be demonstrated that complement factors located on one cell can be induced by enzymes on adjacent cells to form a bridge between these two cells.