In vivo suppression of early experimental osteoarthritis by interleukin‐1 receptor antagonist using gene therapy

Abstract

Objective. This study explored the therapeutic effect of interleukin‐1 receptor antagonist (IL‐1Ra), administered by gene transfer, on the progression of osteoarthritic (OA) lesions in an experimental dog model. Methods. Seventeen mature mongrel dogs were divided into 3 groups. Group 1 (n = 7) had an anterior cruciate ligament (ACL) section of the right knee through a stab wound incision. Groups 2 and 3 (n = 5 per group), had an ACL section of the right knee and partial synovectomy of the left knee. Each dog's synovium was subjected to enzymatic digestion, and the synovial fibroblasts were propagated in monolayer culture. Synovial cells from each dog were transduced in vitro using the retrovirus MFG with either the Escherichia coli β‐galactosidase (lac Z) gene (group 2) or the human IL‐1Ra gene (group 3). Two days after surgery, the dogs received intraarticular injections as follows: group 1 phosphate buffered saline (PBS) (2 ml); group 2 autologous cells (60 × 106 cells/2 ml of PBS) transduced with the lac Z gene; group 3 autologous cells transduced with the IL‐1Ra gene. Synovial fluid was aspirated at 2 weeks and 4 weeks. All dogs were euthanized at 4 weeks postsurgery. The right knees were dissected, and lesions were scored for macroscopic and microscopic changes. Synovial explants were dissected and representative specimens were used for histology or were cultured for 48 hours. The levels of IL‐1Ra in synovial fluid and synovial explant conditioned medium were measured by specific enzyme‐linked immunosorbent assay. Results. The level of IL‐1Ra in synovial fluid of group 3 was 202.8 ± 131.5 ng/ml (mean ± SEM) at 2 weeks and 2.8 ± 2.2 ng/ml at 4 weeks after surgery. Membrane explants isolated from dogs that received synovial cells transduced with the IL‐1Ra gene (group 3) actively produced IL‐1Ra (4.0 ± 2.0 ng/gm of tissue wet weight). The severity of OA cartilage lesions was similar in groups 1 and 2. In contrast, group 3 dogs had a marked reduction in macroscopic lesion severity on the tibial plateaus (P < 0.01 for grade; P < 0.04 for size) and femoral condyles. Moreover, the histologic lesion severity was decreased on both plateaus (P < 0.06) and condyles. Conclusion. This study showed that a local increase in IL‐1Ra production in OA knee joints by intraarticular injection of transduced synovial cells can reduce the progression of experimentally induced lesions.

Restoration of the extracellular matrix in human osteoarthritic articular cartilage by overexpression of the transcription factor SOX9

“…Additional studies in established experimental models (7,8) will be required in order to evaluate the effects of SOX9 overexpression in OA cartilage in vivo. The present findings provide motivation to further develop this therapeutic gene-transfer approach to the treatment of OA in humans.…”

“…Application of therapeutic genes to OA cartilage may offer potent alternatives for reestab- Most of the current approaches to restoring the physiologic balance in injured articular cartilage are based on the delivery of factors that modulate the metabolic functions of chondrocytes, such as agents that counteract the processes of matrix degradation or ones that enhance the synthesis of matrix components. Protective effects of an IL-1 receptor antagonist (IL-1Ra) sequence against IL-1-induced cartilage breakdown have been documented in experimental models ex vivo (5,6) and in vivo (7,8). The transfer of the gene for a heat-shock protein (Hsp70) was also shown to afford protection against cellular injuries in chondrocytes (9).…”

“…Protective effects of an IL-1 receptor antagonist (IL-1Ra) sequence against IL-1-induced cartilage breakdown have been documented in experimental models ex vivo (5,6) and in vivo (7,8). The transfer of the gene for a heat-shock protein (Hsp70) was also shown to afford protection against cellular injuries in chondrocytes (9).…”

Induction of matrix metalloproteinase 1 gene expression is regulated by inflammation‐responsive transcription factor SAF‐1 in osteoarthritis

“…In animal models, intraarticular injection of IL-1␤ has been shown to accelerate the onset of collagen-induced arthritis (11). Reciprocally, inhibition of IL-1 activity by intraarticular injection of IL-1 receptor antagonist (IL-1Ra) or IL-1Ra gene transfection was found to retard the progression of OA (12,13).…”

Gene Therapy of Arthritis.

“…These strategies are discussed in reference (42). There is only one published report in which gene therapy has been attempted in an animal model of OA (43). In this study, a retrovirus wasused to transfer an IL-IRa CDNA to the synovial lining of canine knees after transection of the anterior cruciate ligament.…”