Follicular dendritic cells share a membrane-bound protein with fibroblasts

✍ Scribed by Bofill, Margarita; Akbar, Arne N.; Amlot, Peter L.

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 694 KB
• Volume: 191
• Category: Article
• ISSN: 0022-3417
• DOI: 10.1002/(sici)1096-9896(200006)191:2<217::aid-path586>3.0.co;2-6

✦ Synopsis

The expression of a ®broblast antigen (AS02) on a proportion of CD21+ follicular dendritic cells (FDCs) provides evidence in support of their ®broblastic reticular origin. This antigen is expressed on the membrane of tissue ®broblasts but is absent from lymphocytes, macrophages or granulocytes. The distribution of AS02 in conjunction with other FDC markers (DRC-1, RFD3, CD23, IgM, and vitronectin) showed six types of FDCs. AS02 is present in the outer layers of primary and secondary follicles, but gradually decreases and disappears in the centre of germinal centres. In contrast, there is a progressive up-regulation of the other FDC markers. AS02 is reexpressed in involuting FDCs. Intermediate forms from ®broblastic to dendritic appearance are also apparent and occasionally FDC processes contain collagen type I and IV ®bres, a characteristic feature of ®broblasts. In pathological follicles the normal differentiation pattern is disrupted, with persistence of the ®broblast marker, possibly due to altered interactions between FDCs and disrupted lymphocytic patterns. These ®ndings provide new evidence for a local differentiation pathway of ®broblasts to mature FDCs.