Dendritic cell (professional antigen-presenting cell) !
- Cell
Dendritic cells are sentinels in the tissues that grab antigens, travel to the lymph node and switch on naive T cells.
Updated 2026-11-01
What it is
Dendritic cells are branched antigen-presenting cells found in almost every tissue, especially skin and mucosa. They sample their surroundings, and when they sense a microbe they mature, carry its antigens to the draining lymph node and present them to naive T cells together with costimulatory signals. They are the link between innate and adaptive immunity and the most effective cell at starting a new T-cell response.
Key facts
- Origin: bone marrow precursors; some arise from monocytes during inflammation.
- Two main kinds in blood and tissue: conventional (myeloid) and plasmacytoid dendritic cells.
- Plasmacytoid dendritic cells produce large amounts of type I interferon during viral infection.
Step by step
- An immature dendritic cell in the skin or mucosa samples material by phagocytosis and pinocytosis.
- Toll-like receptors sense a microbe and the cell matures.
- It processes antigens into peptides and loads them onto MHC molecules.
- It raises CD80/CD86 and CCR7 and migrates through lymph to the regional node.
- In the paracortex it presents antigen to naive T cells, giving signal 1 (MHC-peptide) and signal 2 (B7 to CD28).
Markers
- MHC class II (high)
- CD80/CD86 (B7)
- CD11c
- CD1a (Langerhans cells)
- CCR7 when mature
Clinical notes
- Langerhans cell histiocytosis: clonal proliferation of Langerhans-type cells, with lytic bone lesions and skin rashes, mostly in children.
- Contact dermatitis begins when skin dendritic cells pick up a small chemical bound to self-proteins.
- Vaccines and adjuvants work largely by activating dendritic cells.
Test yourself
Think of the answer, then tap the question to see it.
Which cell is the most effective at activating naive T cells?
The dendritic cell.
What two signals does a dendritic cell give a naive T cell?
Signal 1: peptide on MHC to the T-cell receptor; signal 2: B7 (CD80/CD86) to CD28.
Which dendritic cells live in the epidermis, and what marks them?
Langerhans cells, which express CD1a and contain Birbeck granules.
Which dendritic cell type makes large amounts of type I interferon?
The plasmacytoid dendritic cell.
Related
- Monocyte and macrophage
- Lymph node: cortex, paracortex, medulla
- Antigen processing and presentation
- T-cell activation: two signals and superantigens
- CD4⁺ helper T cell
- CD8⁺ cytotoxic T cell
Educational content on the immune system; not a treatment or individual vaccination guide and no substitute for a health professional's advice. No doses are given.
Sources: Dendritic Cells (British Society for Immunology, 2024); 21.3 The Adaptive Immune Response: T lymphocytes and Their Functional Types (OpenStax, Rice University (Anatomy and Physiology 2e), 2022); 21.2 Barrier Defenses and the Innate Immune Response (OpenStax, Rice University (Anatomy and Physiology 2e), 2022).
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Representative model, for educational purposes only.