Cross-presentation

Cross-presentation is the ability of certain antigen-presenting cells to take up, process and present extracellular antigens with MHC class I molecules to CD8 T cells (cytotoxic T cells). Cross-priming, the result of this process, describes the naive cytotoxic CD8 T cell stimulation. This process is necessary for immunity against most tumors and against viruses that do not readily infect antigen-presenting cells, or impair dendritic cell normal function . It is also required for induction of cytotoxic immunity by vaccination with protein antigens, for example, tumour vaccination.