Trogocytosis

Trogocytosis is a rapid, contact-dependent process in which a recipient cell extracts and internalizes patches of the donor cell’s plasma membrane during close cell–cell interaction. The transfer often includes surface proteins, lipids, and other membrane components, rather than whole cells or large amounts of cytoplasm. The term describes a nibbling-like exchange that can alter the surface composition of both participating cells.

The phenomenon has been most extensively studied in the immune system. It occurs when immune cells such as T cells, B cells, natural killer cells, dendritic cells, and macrophages come into contact with other cells expressing compatible membrane molecules. Trogocytosis typically takes place at or near an immunological synapse and depends on cytoskeletal remodeling, receptor–ligand engagement, and, in some contexts, Fc receptor signaling. It can occur via direct membrane transfer during transient cell contact or through antibody-mediated mechanisms that promote membrane patch uptake.

Functional consequences are diverse. The recipient cell can acquire donor-derived MHC antigens or costimulatory molecules, a phenomenon sometimes called cross-dressing, which can influence antigen presentation and T cell responses. Conversely, donor cells may lose surface proteins, such as receptors or antigens, potentially contributing to immune evasion or altered signaling. Clinically, trogocytosis has been implicated in contexts such as antibody therapies, where effector cells can remove therapeutic epitopes from targets (antibody shaving), and in shaping immune interactions and tolerance. While the exact biological implications continue to be explored, trogocytosis is recognized as a mechanism of intercellular membrane exchange that can modulate immune communication.