Figure 5

Reduction of the size and cell density of rheumatoid arthritis (RA) synovium in vivo by repeated Fas ligand (FasL) gene transfer. (a) RA synovium, 200 mg tissue per mouse, was grafted into the back of each severe combined immunodeficiency (SCID) mouse subcutaneously. Two weeks after engraftment, 10¹¹ particles of recombinant FasL adenovirus (Ad-FasL) or Ad-LacZ adenovirus (Ad-LacZ) in 0.1 ml PBS were injected into the engrafted RA synovium in the SCID mice. Injections were repeated every two weeks for a total of five times. Three days after the fifth injection, the mice were euthanized and the RA synovium samples were collected, weighed, and examined with hematoxylin and eosin (H&E) staining. (b) A comparative view of the size of the grafted RA synovium after two months of repeated treatment with control Ad-LacZ (tissue on the left side) and Ad-FasL (tissue on the right side). (c) H&E staining shows that both synoviocytes and mononuclear cells are greatly decreased in Ad-FasL treated RA synovium, in which a partial recovery of the normal features of synovium was observed (original magnification 200×); (d) but the Ad-LacZ treated RA synovium maintains the inflammatory infiltrates (original magnification 200×)