Cross-presentation by human dendritic cell subsets

• Murine DC subsets can be classified in several lineages that differ in their phenotype and functional properties, in particular in their ability to cross-present antigens.
• In humans, distinct DC subpopulations have also been identified. Comparative transcriptomic analysis suggests homology between mouse and human DC lineages.
• The intracellular mechanisms involved in cross-presentation are conserved between mouse and human DCs, but the specialization of one lineage over others is not.

Dendritic cells (DCs) are a heterogeneous population of professional antigen-presenting cells. Several murine DC subsets differ in their phenotype and functional properties, in particular in their ability to cross-present antigens (i.e. to present exogenous antigens on their MHC class I molecules). In humans, distinct DC subpopulations have also been identified but whether some human DC subsets are also specialized at cross-presentation remains debated. Here we review the DC subsets that have been identified in humans and we discuss recent work that addresses their ability to cross-present antigens and their efficiency for CD8+ T cells activation.