Dendritic cells (DC) are highly efficient antigen-presenting cells (APC) that have an essential function in the development of immune responses against microbial pathogens and tumors. Although during the past few years our understanding of DC biology has remarkably increased, a precise characterization of the different DC subpopulations remains to be achieved with regard to their phenotype and lineage relationships. In this report, we have extensively studied the DC subpopulations present in the thymus, spleen, Peyer’s patches, lymph nodes (LN) and skin of the mouse. Thymus DC and 60% spleen DC have a lymphoid DC phenotype, ie, CD8+DEC-205high Mac-1low, whereas 40% spleen DC have a myeloid DC phenotype, ie, CD8−DEC-205low Mac-1high. Both CD8+and CD8− DC are leukocyte function-associated antigen-1 (LFA-1)high and highly adherent. Within Peyer’s patches the majority of DC correspond to the CD8+DEC-205high Mac-1lowlymphoid category. In the LN, together with CD8+ and CD8− DC, an additional nonadherent CD8intLFA-1int subpopulation with lymphoid DC characteristics is described. Finally, in the skin both epidermal Langerhans cells (LC) and dermal DC are CD8−DEC-205high Mac-1high , and do not express LFA-1. Interestingly, LC migration experiments indicate that LC underwent the upregulation of CD8 and LFA-1 upon migration to the LN, supporting the hypothesis that LC belong to the CD8+ lymphoid lineage.
Characterization of Immunological Niches within Peyer’s Patches by ex vivo Photoactivation and Flow Cytometry Analysis
