FIGURE 11.

Possible effects of cell membrane fluctuations on T cell function. (A) An illustration of an immune synapse between an effector T cell with its specific TCR and a benign target cell with a complimentary pMHC. Both cell membranes and their attached cortical actin are mechanically vibrating but to a different extent. Resultant perpendicular forces act on the TCR-pMHC complex, leading to its modified lifetime. The benign target cell membrane is relatively firm and stable. The more pronounced membrane fluctuations of the effector T cell could effectively produce repeated and precise rupture forces on the TCR-pMHC complex to generate effective cellular response. (B) A similar illustration of an immune synapse between effector T cell and a malignant target cell. The malignant target cell membrane and its underlying cortical actin are less firm and fluctuate more relative to benign cells [as in panel (A)]. The fluctuations of the effector T cell are milder relative to the membrane fluctuations of the malignant target cell. Thus, the TCR-pMHC complex is subject to incoherent forces, abrogating precise and organized activation of the TCR and the effector T cell. This may further lead to possible immune evasion of the malignant cell.