¹The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia

Correspondence: Dr AM Lew, The Walter and Eliza Hall Institute of Medical Research, 1G Royal parade, Parkville, Victoria 3050, Australia. E-mail: lew@wehi.edu.au

Received 20 November 2007; Revised 8 January 2008; Accepted 11 January 2008; Published online 12 February 2008.

Abstract

The cell biology of cross-presentation is reviewed regarding exogenous antigen uptake, antigen degradation and entry into the major histocompatibility complex class I pathway. Whereas cross-presentation is not associated with enhanced phagocytic ability, certain receptors may favour uptake for cross-presentation for example mannose receptor for soluble glycoproteins. Perhaps, the defining property of the cross-presenting cell is some specialization in host machinery for handling and transport of antigen across organelles. Both cytosolic and vacuolar pathways are discussed. Which dendritic cell (DC) subset is the cross-presenting cell is explored. Cross-presentation is found within the CD8⁺ subset resident in lymphoid organs. The role of other DC subsets (especially the migratory CD8^- DC) and the route of antigen delivery are also discussed. Further consideration is given to antigen transfer between DC subsets and differential presentation to naive vs memory T cells.