Host Immune Responses to Intradiscal Gene Transfer / 대한척추외과학회지

PURPOSE: To elucidate host immune responses to intradiscal gene transfer. MATERIALS AND METHODS: Twenty rabbits were utilized. Ad/luciferase (adenovirus construct) were injected into nucleus pulposus of lumbar vertebrae. Group 1 received intradiscal injection of Ad/luciferase only, Group 2 received subcutaneous and intradiscal injection simultaneously, Group 3 received subcutaneous injection then intradiscal injection with 2 weeks interval. Blood samples were obtained serially after injection. Animals were sacrificed at 7 weeks. Antibody to adenovirus in peripheral blood was measured with ELISA and transgene expression was measured with standard luciferase kits. RESULTS: All rabbits in the Group 2 and 3 exhibited increased production of neutralizing antibody. There were clearly two subgroups in Group 1, three rabbits exhibited production of antibody but remaining three rabbits showed little or no production of antibody. All rabbits showed robust increase in transgene expression regardless of titer of neutralizing antibody. CONCLUSION: The intervertebral disc is favorable site for adenovirus-mediated gene transfer escaping from systemic immunity.

Transforming Growth Factor-beta1 and Bone Morphogenetic Protein-2 Upregulates Matrix Synthesis and Chondrogenic Phenotype in Intervertebral Disc Cells / 대한척추외과학회지

OBJECTIVES: To determine effect of transforming growth factor-beta1 and bone morphogenetic protein-2 in matrix synthesis and expression of chondrogenic phenotype in human intervertebral disc cells. MATERIALS AND METHODS: The intervertebral disc cells were harvested and cultured from the surgical patients for the degenerative disc disease. TGF-beta1 was purchased from R&D and BMP-2 was produced by transfection of pcDNA3.1/Hygro/BMP-2 to CHO cell using Lipofectamine 2000. rhBMP-2 was separated by Heparin-Sepharose A chromatography. TGF-bata1 and BMP-2 were administered to culture. Proteoglycan synthesis was assessed by 35S incorporation and expression of matrix mRNA was analyzed by RT-PCR for collagen I, collagen II, aggrecan, and osteocalcin. RESULTS: TGF-bata1 and BMP-2 showed increased proteoglycan synthesis and expression of collagen I, collagen II and aggrecan mRNA in dose dependent manner respectively. There was no recognizable synergistic effect in matrix synthesis and matrix mRNA expression. Throughout dosage, expression of osteogenic phenotype (osteocalcin mRNA) was not noted. CONCLUSION: TGF-beta1 and BMP-2 proved to be effective anabolic agent for maximizing matrix synthesis without evidence of osteogenesis.