Immortalized Human Chondrocytes-hTERT

Generation of Human Immortalized Chondrocytes from Osteoarthritic and Healthy Cartilage

After a few passages of in vitro culture, primary human articular chondrocytes undergo senescence and loss of their phenotype. Most of the available chondrocyte cell lines have been obtained from cartilage tissues different from diarthrodial joints, and their utility for osteoarthritis (OA) research is reduced. This study aims to establish immortalized chondrocyte cell lines proceeded from the articular cartilage of patients with and without OA.

Primary articular chondrocytes were transduced with telomerase reverse transcriptase (hTERT) and SV40 large T antigen (SV40LT). Proliferative capacity, degree of senescence, and chondrocyte surface antigen expression in transduced chondrocytes were evaluated. Furthermore, their capacity to synthesize a tissue similar to cartilage and to respond to interleukin (IL)-1β was assessed.

Co-expression of both transgenes (SV40 and hTERT) were observed in the nuclei of transduced chondrocytes. Generated chondrocyte cell lines showed a high proliferation capacity and less than 2% of senescent cells. These cell lines were able to form 3D aggregates analogous to those generated by primary articular chondrocytes, but were unsuccessful in synthesizing cartilage-like tissue when seeded on type I collagen sponges. However, generated chondrocyte cell lines maintained the potential to respond to IL-1β stimulation.