%A Janssen,Edith %A Thacker,Robert %D 2012 %J Frontiers in Immunology %C %F %G English %K antigen processing,cell-associated antigen,cross-presentation,dendritic cell,type I IFN %Q %R 10.3389/fimmu.2012.00041 %W %L %M %P %7 %8 2012-March-14 %9 Review %+ Dr Edith Janssen,Cincinnati Children's Hospital Research Foundation,Molecular Immunology,3333 Burnet Avenue,MLS7021,Cincinnati,45229,Ohio,United States,ejanssen@its.jnj.com %# %! Cross-presentation of cell-associated antigens by splenic DCs %* %< %T Cross-Presentation of Cell-Associated Antigens by Mouse Splenic Dendritic Cell Populations %U https://www.frontiersin.org/articles/10.3389/fimmu.2012.00041 %V 3 %0 JOURNAL ARTICLE %@ 1664-3224 %X Cross-presentation of cell-associated antigens (Ag) plays an important role in the induction of anti-tumor responses, autoimmune diseases, and transplant rejection. While several dendritic cell (DC) populations can induce pro-inflammatory CD8+ T cell responses to cell-associated Ag during infection, in the absence of infection, cross-priming of naïve CD8+ T cells is highly restricted. Comparison of the main splenic DC populations in mice – including the classic, cross-presenting CD8α DC and the recently described merocytic DC (mcDC) – reveals that cross-priming DCs display a distinct phenotype in cell-associated Ag uptake, endosomal/lysosomal trafficking, lysosomal acidification, and Ag persistence compared to non-cross-priming DC populations. Although the CD8α DC and mcDC subsets utilize similar processing pathways to cross-present cell-associated Ag, cross-priming by CD8α DCs is associated with IL-12 production, while the superior priming of the mcDC is critically dependent on type I IFN production. This discussion illustrates how subtle differences in internal processing pathways and their signaling sequelae significantly affect the duration of Ag cross-presentation and cytokine production by DCs, thereby shaping the ensuing CD8+ T cell response.