title: Adenoviral mediated delivery of FAS ligand to arthritic joints causes extensive apoptosis in the synovial lining.
abstract: BACKGROUND
  Rheumatoid arthritis (RA) is an autoimmune disease where the synovial lining layer of the joint becomes thickened, hypercellular, and highly aggressive. Invading synovial tissue erodes cartilage and subchondral bone and leads to loss of joint function. FasL, a cell-surface molecule on activated T-cells interacts with its receptor, Fas, to induce apoptosis in target cells. We addressed the feasibility of using adenoviral gene transfer of FasL therapeutically to mediate apoptosis in arthritic joints similar in size to the small joints of the hands and feet that are the primary sites of RA in humans.
  
  
  METHODS
  Adenoviral vectors were used to transfer FasL and LacZ cDNAs into human RA and rabbit synovial fibroblasts in culture where apoptosis was evaluated using MTT and TUNEL analyses. The ability of Ad.FasL to mediate synovial apoptosis in vivo was then addressed in an IL-1-induced arthritis model in the rabbit knee.
  
  
  RESULTS
  In culture, delivery of FasL was found to efficiently induce apoptosis in both human RA and rabbit synovial fibroblasts. The ability of Ad.FasL to induce synovial apoptosis was then evaluated in rabbit knee joints. 24 h after intra-articular injection of 10(11) Ad.FasL particles, large regions of synovial tissue were observed histologically consisting primarily of fibrous matrix and cellular debris. TUNEL staining of corresponding sections was highly positive for fragmented DNA. Glycosaminoglycan (GAG) synthesis from cartilage shavings from treated joints suggests that Ad.FasL does not induce significant apoptosis in resident articular chondrocytes.
  
  
  CONCLUSIONS
  Infection of human and rabbit synovial fibroblasts with Ad.FasL results in significant apoptotic cell death in vitro. Direct intra-articular injection of Ad.FasL in the arthritic rabbit knee results in extensive apoptosis in the synovium without affecting chondrocyte viability.
authors.affiliation: Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, PA 15219, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Yao
authors.forename: J C
authors.initials: JC
authors.lastname: Glorioso
authors.forename: C H
authors.initials: CH
authors.lastname: Evans
authors.forename: P D
authors.initials: PD
authors.lastname: Robbins
authors.forename: I
authors.initials: I
authors.lastname: Kovesdi
authors.forename: T J
authors.initials: TJ
authors.lastname: Oligino
authors.forename: S C
authors.initials: SC
authors.lastname: Ghivizzani
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D001172:Arthritis, Rheumatoid / Q000473:pathology / Q000628:therapy*; D002358:Cartilage, Articular / Q000473:pathology*; D002478:Cells, Cultured; D053222:Fas Ligand Protein; D005347:Fibroblasts; D005822:Genetic Vectors; D006801:Humans; D066298:In Vitro Techniques; D007719:Knee Joint / Q000473:pathology; D008562:Membrane Glycoproteins / Q000235:genetics*; D011817:Rabbits; D013583:Synovial Membrane / Q000473:pathology*
chemical_list: C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins