Trogocytosis

Image: On electron microscope images from the ADCC, PMN could be observed that had tightly bound to the target cells through finger-like membrane protuberances.

Trogocytosis ( Greek “trogo” = gnaw ) is an active transfer phenomenon in which lymphocytes (B, T and NK cells), which conjugate via immunological synapses with antigen-presenting cells , take up surface molecules from them. Trogocytosis must be clearly differentiated from phagocytosis .

The conjugation of B, T and NK cells with target cells, in vivo as well as in vitro , results in a transfer of plasma membrane fragments from the presenting cell (target cell) to the lymphocytes . It is specifically triggered by antigen-receptor signaling and could play an important role in inducing the regulation of the immune response and possibly in the control of other cellular systems.

Trogocytosis by cytotoxic T lymphocytes apparently contributes to the selection of high affinity T cells by removing presented antigens from dendritic cells and also eliminating cytotoxic T lymphocytes. The latter phenomenon is probably not physiological . Trogocytosis may first have established itself in the most primitive organisms to feed on other cells.

Individual evidence

1. ↑ E. Joly, H. Hudrisier: What is trogocytosis and what is its purpose? In: Nat Immunol . 4 (9), Sep 2003, p. 815. PMID 12942076