GSE116161
RNA-seq of Arc/Arg3.1-positive versus Arc/Arg3.1-negative skin migratory dendritic cells from healthy mice
The key function of migratory dendritic cells (migDCs) is to take up antigens in peripheral tissues and migrate to draining lymph nodes (dLN) to initiate immune responses. Recently, we discovered in mice that in the immune system activity-regulated cytoskeleton associated protein/activity-regulated gene 3.1 (Arc/Arg3.1) is exclusively expressed by migDCs and is a central driver of fast inflammatory migration. However, the frequency of Arc/Arg3.1 expressing cells in different migDC subsets including Langerhans cells (LC), their phylogenetic origin, transcription factor dependency and functional role remains unclear. Here we found that Arc/Arg3.1+ migDCs derived from common DC precursors (CDPs) and radio-resistant LCs. They were present in all migDC subsets and showed a consistent superiority in inflammatory migration but were independent of the transcription factors Irf4 or Batf3. In intradermal Staphylococcus aureus infection, a model that relies on effective inflammatory antigen transport, Arc/Arg3.1 deletion strongly reduced T cell responses. By contrast, Arc/Arg3.1 deficiency did not hamper the immune response to systemic Listeria monocytogenes infection, which does not require antigen transport. Thus, our results show that Arc/Arg3.1 is a molecular marker for defining a population of DCs with superior migratory capacity that spans across all migDC subsets irrespective of ontogeny and phenotype. Overall design: Arc/Arg3.1-eGFP-positive and Arc/Arg3.1-eGFP-negative migratory dendritic cells (MHC-II-high, CD11c-intermidiate) were isolated by fluorescent cell sorting from skin draining lymph nodes of Arc/Arg3.1-eGFP mice.