ABSTRACT
Max Plank-Institute for Physiological and Clinical Research,Bad Nauheim, Germany
The last years have seen a rapid advent of knowledge of the physiological and pathophysiological functions of TNF and TNFrelated ligands. Each member of this ligand family is paired with one or more specific cell surface receptor(s) that together form a corresponding family of receptors. Research in this area was boosted by the recent identifaction of a variety of new members in both, the ligand and the receptor superfamily. The ability of some members of the TNF-receptor family to induce cell death has attracted great attention. In addition, with the improvement of molecular technologies and the development of refined animal models, the pivotal role of TNF and TNF-related cytokines for the stimulation of immune and nonimmune cells has become obvious. Although initial studies focussed on the soluble forms of these ligands, most of these molecules are expressed as transmembrane proteins and accordingly act in situations of direct cell-to-cell contact. Furthermore, recent reports on bidirectional signalling mediated by the “ligands” of the TNF-family shaked the classical ligand receptor concept. In this report we review some aspects of the biological and pathophysiological functions of the molecules of the TNF-/TNF-receptor superfamilies and attempt to summarize recent developments and informations on lately discovered molecules.
