The origin of type A synovial lining cells.
Type A synovial lining cells resemble macrophages in their ultrastructure. Type B lining cells, in contrast, resemble tissue fixed synthetic cells such as fibroblasts. Although cells with intermediate features are well recognised, recent evidence suggests that types A and B cells have different origins. Experiments on mouse radiation chimeras suggest a bone marrow derivation for the type A cells, but not for the type B. Esterase activity, surface Ia, and immunoglobulin receptors have been demonstrated in relation to a proportion of lining cells. It seems reasonable at the present time to consider type A lining cells as belonging to the Mononuclear Phagocyte System.
D000818:Animals; D001172:Arthritis, Rheumatoid / Q000473:pathology; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D005347:Fibroblasts / Q000648:ultrastructure; D006801:Humans; D008247:Lysosomes / Q000648:ultrastructure; D008264:Macrophages / Q000145:classification / Q000166:cytology; D051379:Mice; D008815:Mice, Inbred Strains; D009000:Monocytes / Q000145:classification / Q000166:cytology; D010586:Phagocytes / Q000145:classification / Q000166:cytology; D051381:Rats; D013583:Synovial Membrane / Q000166:cytology* / Q000648:ultrastructure