From Natural History to Molecular Physics and Medical Applications

How and why do certain cells fuse their plasma membranes to form hybrid, multinucleated, or even giant cells? Cell-cell fusion occurs only under special circumstances during the life cycle of any organism. Yet cell fusion is seen in virtually all phyla of eukaryotes. In humans, cell fusions are critical to formation of the new embryo, placenta, muscle and bone, eye, and immune cells. However, we have little understanding of the mechanisms that allow such cells to undergo this profound developmental and cell-biological change, a transition that instantly alters their form, function, and fate.

The Cell-Cell Fusion GRC is a forum where multiple disciplines converge to attack this common problem from their various points of expertise: model biological systems where cell fusion occurs and models of the interactions of lipids and proteins that can lead to membrane bilayer merger. One major goal is to find where these systems share common features - molecules and higher-order structures - and where systems truly diverge, invoking unique approaches to the same ultimate task. Another is to comprehend the functional impact of fusion on the syncytial or hybrid cells that are formed: how polyploid, multinucleate or giant cells benefit survival of the organism. The ultimate goal is to find applications where the control of cell fusion will benefit human health, through controlled fertility, better healing, enhanced immunity, augmented food production, or other means.

The 2009 conference featured advances in understanding of the diverse biological systems that were presented at the inaugural meeting in 2007, including model organisms where molecular details at the heart of the mechanism have begun to emerge. This meeting also covered additional species and cell types, other newly found modes of plasma membrane fusion, and more of the physics behind the influence of proteins and lipids on the shape of membranes - and the influence of membrane shape upon fusion. Finally, we learned of novel interventions in medicine where artificial cell fusion may enable treatment of devastating diseases.