ABSTRACT
Reorganization within the T-cell cortical actin cytoskeleton takes place when T cells interact with B cells or other target cells through cell-surface receptors. The functions of T cells in immune defense all involve interactions with other cells that are initiated by direct cell-cell contact via cell-surface receptors. For example, helper T cells interact with B cells through cell-surface receptors to stimulate B-cell proliferation and the subsequent differentiation into antibodyproducing plasma cells. T-cell-B-cell interactions are also involved in isotype switching and generation of memory cells, whereas cytotoxic T-cell killing of virus-infected target cells also involves direct contact with the target cell.
