TRANSFER OF GENES TO CHONDROCYTIC CELLS OF THE LUMBAR SPINE - PROPOSAL FOR A TREATMENT STRATEGY OF SPINAL-DISORDERS BY LOCAL GENE-THERAPY

Study Design. In the current study, chondrocytic cells from bovine int ervertebral end plates were cultivated in vitro and modified genetical ly. Objective. The authors intended to perform isolation and cultivati on of cells from bovine end plates of the spine, They also intended to show, in principle, the feasibility of introducing exogenous genes in to chondrocytic cells from bovine intervertebral end plates by way of retroviral vectors. Summary of Background Data. The involvement of cyt okines in the destruction of articular cartilage is established. It ap pears possible that similar mechanisms may play a role in intervertebr al disc degeneration and other spinal disorders. Conventional medicati on and surgery of intervertebral disc degeneration addresses neither t he pathophysiology nor the chronicity of the disease. Therapeutic prot eins carry great potential as locally produced drugs after transfer of their cognate genes to the sites of interest. Methods. Vertebral end plate tissue was obtained from bovine os coccygis. Chondrocytic cells were isolated and cultured in vitro. The bacterial beta-galactosidase (LacZ) gene and, alternatively, the complementary DNA (DNA copy of the mRNA) of the human interleukin-1 receptor antagonist were introduced into the isolated cells by retrovirus mediated gene transfer. beta-gal actosidase activity was determined by staining, and interleukin-1 rece ptor antagonist protein was quantitated by enzyme-linked immunosorbent assay. Results. Isolation and cultivation of chondrocytic end plate c ells is possible. Native cells continue to grow in culture for more th an 2 months. Transfer of the beta-galactosidase gene to cultured cells resulted in similar to 1% beta-galactosidase positive cells. Transfer of the interleukin-1 receptor antagonist complementary DNA resulted i n the production of 24 ng/ml/10(6) cells interleukin-1 receptor antago nist protein in 48 hours. Conclusions. The introduction of exogenous t herapeutic genes into cells from the intervertebral end plate opens th e possibility for a local gene based treatment of intervertebral disc degeneration, This approach avoids some of the shortcomings of convent ional drug- and surgery-based treatments and has the potential to be s pecific, effective, and appropriate to the chronicity of the disease.