Trogocytosis-mediated immune evasion in the tumor microenvironment

Trogocytosis is a dynamic cellular process characterized by the exchange of the plasma membrane and associated cytosol during cell-to-cell interactions. Unlike phagocytosis, this transfer maintains the surface localization of transferred membrane molecules. For example, CD4 T cells engaging with antigen-presenting cells undergo trogocytosis, which facilitates the transfer of antigen-loaded major histocompatibility complex (MHC) class II molecules from antigen-presenting cells to CD4 T cells. This transfer results in the formation of antigen-loaded MHC class II molecule-dressed CD4 T cells. These “dressed” CD4 T cells subsequently participate in antigen presentation to other CD4 T cells. Additionally, trogocytosis enables the acquisition of immune-regulatory molecules, such as CTLA-4 and Tim3, in recipient cells, thereby modulating their anti-tumor immunity. Concurrently, donor cells undergo plasma membrane loss, and substantial loss can trigger trogocytosis-mediated cell death, termed trogoptosis. This review aims to explore the trogocytosis-mediated transfer of immune regulatory molecules and their implications within the tumor microenvironment to elucidate the underlying mechanisms of immune evasion in cancers. Trogocytosis is a process where cells exchange membrane proteins, first noted in the 1970s, and it affects immune responses. Membrane proteins are molecules that help cells communicate and interact. Researchers emphasized its importance in how immune cells interact. This review discusses trogocytosis in the tumor microenvironment, influencing both immune and cancer cells. The study explains that trogocytosis allows cells to “nibble” on others, transferring membrane properties, which can change the function of immune cells like T cells and NK cells. Various methods were used to study these interactions, focusing on immune and cancer cells. Findings indicate that trogocytosis can either suppress or enhance immune responses, affecting cancer therapies such as CAR-T cells. Understanding trogocytosis could improve cancer treatments by adjusting immune responses, and future research might explore its mechanisms to boost immunotherapy. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.