Antigen-presenting cell function enhancement via allogeneic MHC expression

Antigen-presenting cell function enhancement via allogeneic MHC expression refers to the phenomenon where APCs (such as dendritic cells, macrophages, or B cells) acquire or express allogeneic (foreign) MHC molecules from donor cells, typically in the context of transplantation. This can happen via cell-cell contact (trogocytosis), uptake of extracellular vesicles (exosomes) containing allogeneic MHC, or other mechanisms. This process ("MHC cross-dressing" or semidirect allorecognition) allows recipient APCs to present intact foreign MHC-peptide complexes to recipient T cells, enhancing their capacity to trigger alloimmune responses. This mechanism is important in the context of transplantation, as it can facilitate rapid and robust rejection of transplanted tissue by enabling more efficient T cell activation against donor antigens[1][2][3][5]. Caveats: Not a druggable molecule or traditional drug target. Best interpreted as a mechanism/process; if a molecular target is sought, further clarification (e.g., "HLA-DRB1" or "MHC class I molecule") would be necessary.

Other names

MHC cross-dressingSemidirect allorecognitionAllogeneic MHC acquisition by antigen-presenting cells

Indirect effect via modulation of APC- and T cell-mediated immune activation