Biomechanics of virus-to-cell and cell-to-cell fusion.

A biomechanical model of virus-to-cell and cell-to-cell fusion is presented. Virus and the cells are modelled as initially spherical membranes of nonlinear elastic material that undergo large deformations. The membranes are connected by a cytoplasmic bridge which expands, resulting in the formation of a larger single sphere. In virus-to-cell fusion, a smaller spherical membrane is connected to a much larger one. Fusion is completed when the smaller membrane is completely incorporated into the larger one. The numerical results predict the existence of a ring force in the so-called furrow plane. It is possible that the microfilaments of the cortical layer form the furrow band which may provide this ring force.