Pulmonary dendritic cells require cis-activation to cross-prime T cells (APP4P.117)

Abstract

Abstract Dendritic cells (DCs) are required for the induction of cytotoxic T cells (CTL). In most tissues, including the lung, the resident migratory DC fall into two types, respectively expressing the integrin markers, CD103 and CD11b. The current supposition is that DC function is predetermined by lineage, designating the CD103+ DC as the major cross-presenting DC able to induce CTL. Here we proposed that DC function might also be determined by the nature of the pathogen associated molecular pattern (PAMP) that stimulates it and to which it is able to respond. Thus, in the presence of a TLR3 (CD103+) or a TLR7 (CD11b+) agonist respectively we demonstrated in vivo that both DC subtypes did exhibit the capacity to orchestrate a CTL response. This selectivity did not extend to antigen cross-presentation for T cell proliferation but was required for induction of cytotoxicity and protection in a model of tumor metastasis.