File:Spleen structure 01.jpg

Spleen Structure

Schematic representation of the organization of the spleen (left panel).

• The white pulp consists of T cell zones (also known as the periarteriolar lymphoid sheath (PALS)) containing networks of fibroblastic reticular cells (FRC) surrounding a central arteriole, together with B cell follicles containing a central network of follicular dendritic cells (FDC).
• Marginal zones (MZ) surrounding the white pulp contain marginal reticular cells (MRC), particularly at the edges of the B cell follicles.
• Blood and leukocytes entering the spleen pass through branches of the central arteriole, which end in the marginal sinuses and red pulp.
• In the cords of the red pulp, a dense network of reticular fibroblasts and fibres construct an open blood network, which is marked by its lack of a typical endothelial cell lining.
• Large numbers of macrophages phagocytose dying or damaged red blood cells in the red pulp (not shown).
• Immune cells enter the white pulp at regions where the T cell zones abut the MZ, known as the MZ bridging channels.

An image of a section of mouse spleen generated using multicolour immunofluoresence microscopy illustrates the organization of the white pulp, red pulp, and MZ (centre panel). The distribution of CD3+ T cells (white), B220+ B cells (blue), CD169+ MZ macrophages (cyan), CD11c+ dendritic cells (DCs) (green), and ER-TR7+ stromal cells (red) is shown. The distinct organization of stromal cells in different regions of the spleen is shown by single-colour immunofluoresence staining (right panel). Networks of stromal cells and reticular fibres form in the white pulp, including the fibroblastic reticular cells (FRCs) in T cell zones, follicular dendritic cells (FDCs) in B cell follicles (ER-TR7−) and marginal reticular cells (MRCs) in the MZ. A dense network of stromal cells and reticular fibres is present in the red pulp. Scale bars represent 130 μM.

Reference

<pubmed>19644499</pubmed>| PMC2785037 | Nat Rev Immunol.

Mueller

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