blood_and_immune_upper_slim capable of dendritic cell plasmacytoid dendritic cell A dendritic cell type of distinct morphology, localization, and surface marker expression (CD123-positive) from other dendritic cell types and associated with early stage immune responses, particularly the release of physiologically abundant amounts of type I interferons in response to infection. T-associated plasma cell plasmacytoid monocyte type 2 DC pDC https://cellxgene.cziscience.com/cellguide/CL_0000784 DC2 BTO:0004625 interferon-producing cell Plasmacytoid dendritic cells (pDCs), initially known as interferon-producing cells, are a unique subpopulation of dendritic cells. Unlike conventional dendritic cells (cDCs), plasmacytoid dendritic cells are characterized by their distinctive plasma cell-like morphology. These cells play vital roles in the innate and adaptive immune response, particularly in the antiviral response. Highly prevalent in the blood and lymphoid organs, pDCs are rare in non-lymphoid tissues, with the exception of inflamed tissues and tumors where they are often recruited. A key role of plasmacytoid dendritic cells is their rapid and robust production of type 1 interferons in response to viral infections. This is crucial for antiviral defense as interferon signals to other immune cells to increase their antiviral defenses. pDCs achieve this by detecting viral nucleic acids in the cytosol through Toll-like receptors (TLRs), specifically TLR7 and TLR9. Upon recognition, these cells quickly produce substantial amounts of interferons, which plays a significant role in the containment of viral replication and the development of acquired antiviral immunity. The potential of plasmacytoid dendritic cells for antigen presentations to naive T cells is relatively low under steady-state conditions. Upon activation by certain stimuli, such as viruses or CpG oligodeoxynucleotides, they have the ability to differentiate into efficient antigen-presenting cells. This transition to activated cells involves an upregulation of major histocompatibility complex (MHC) class II molecules and co-stimulatory molecules, thus allowing them to effectively present antigenic peptides to naive T cells. This crucial function in linking innate and adaptive immunity underlines the importance of pDCs to the overall immune response. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) lymphoid dendritic cell IPC plasmacytoid T cell type I interferon production Homo sapiens