Cross-presentation of tumor antigens via MHC class I pathway

Cross-presentation of tumor antigens via the MHC class I pathway is a process primarily carried out by professional antigen-presenting cells such as dendritic cells. It enables exogenous (extracellular) antigens, including tumor-derived proteins, to be processed and displayed on MHC class I molecules. This presentation is crucial for activating CD8-positive (cytotoxic) alpha beta-TCR+ T lymphocytes, which can recognize and kill tumor or virally-infected cells. The process involves uptake of antigens, processing via endosomal or cytosolic pathways, peptide translocation and loading onto MHC class I, and surface expression for recognition by T cells. It is essential for effective antitumor immunity, the success of many immunotherapies, and contributes to immune surveillance and viral defense.

Other names

Antigen cross-presentationMHC class I cross-presentation