Transfer of arthritis into distal joints with hTNF-expressing SFs. (a) Histopathological analysis (H & E) of an ankle + 4 weeks after injection with hTNF/TAg SF clone B2 or wt/TAg SF clone F6. Representative diseased ankle joint shows arthritic features of synovitis and signs of chondrocyte loss. Original magnification × 95. (b) PCR amplification of TAg transgene from various tissue samples taken from mice injected in the right knee with the hTNF/TAg SF clone B2, the wt/TAg SF clone F6, and hTNF/TAg lung fibroblasts. +/- = positive and negative controls, respectively; GAPDH = glyceraldehyde-3-phosphate dehydrogenase; H = heart; hTNF = human tumor necrosis factor; LA = left ankle; Li = liver; LK = left knee; Lu = lung; RA = right ankle; RK = right knee; SF = synovial fibroblast; Sp = spleen; TAg = large tumor antigen; Th = thymus; tsTAg = temperature-sensitive large tumor antigen; wt = wild-type. Bars: 100 μm.