Tissue-engineered cartilage with inducible and tunable immunomodulatory properties

Abstract

The pathogenesis of osteoarthritis is mediated in part by inflammatory cytokines including interleukin-1 (IL-1), which promote degradation of articular cartilage and prevent human mesenchymal stem cell (MSC) chondrogenesis. In this study, we combined gene therapy and functional tissue engineering to develop engineered cartilage with immunomodulatory properties that allow chondrogenesis in the presence of pathologic levels of IL-1 by inducing overexpression of IL-1 receptor antagonist (IL-1Ra) in MSCs via scaffold-mediated lentiviral gene delivery. A doxycycline-inducible vector was used to transduce MSCs in monolayer or within 3D woven PCL scaffolds to enable tunable IL-1Ra production. In the presence of IL-1, IL-1Ra-expressing engineered cartilage produced cartilage-specific extracellular matrix, while resisting IL-1-induced upregulation of matrix metalloproteinases and maintaining mechanical properties similar to native articular cartilage. The ability of functional engineered cartilage to deliver tunable anti-inflammatory cytokines to the joint may enhance the long-term success of therapies for cartilage injuries or osteoarthritis.

Anatomically shaped tissue-engineered cartilage with tunable and inducible anticytokine delivery for biological joint resurfacing

“…6B), demonstrating tight control and significant induction of IL-1Ra with the dox-inducible system. Consistent with our previous study (33), there was an increase in total DNA, s-GAG, and collagen content over time in culture (Fig. 7 A-C).…”

“…Additionally, previous strategies have not incorporated regulated gene expression systems. The dox-inducible expression cassette used in this study allows temporal control as well as a dynamic range of IL-1Ra secretion greater than two orders of magnitude (33,55). Although we used this well-described dox-inducible system for the current study, other inducible systems could be used with this same overall strategy if the modulation of anticytokine therapy is indeed beneficial during tissue regeneration.…”

“…Dox-inducible, lentiviral vectors containing the transgenes for IL-1Ra or eGFP were cloned previously (33). The dox-inducible lentivector (TMPrtTA, kindly provided by Olivier Danos, INSERM, Paris) is a "tet-on" system within one vector, which includes the rtTA2S-M2 reverse tetracycline-controlled transcriptional activator constitutively expressed from a human phosphoglycerate kinase promoter (Fig.…”

“…This approach can avoid repeated, systemic injection of expensive biologic drugs, but does not provide a functional replacement for severely damaged cartilage. We have previously developed small cartilage constructs (5-mm disks) that are capable of inducible and tunable IL-1Ra production using scaffoldmediated lentiviral transduction of human MSCs (33). These IL1Ra-expressing constructs were protected from IL-1 signaling, enabling them to develop robust engineered cartilage in an inflammatory environment in vitro.…”

Genetic Engineering of Mesenchymal Stem Cells for Regenerative Medicine

“…The VEGF and human IL-1 receptor antagonist (IL-1Ra)-overexpressing BM-MSCs were shown to protect islet cells from cytokines during islet transplantation [264]. Similarly, the immunomodulatory properties of IL1Ra were also shown in the case of IL-1Ra-modified ASCs [265] and BM-MSCs [266] in a cartilage repair model, where the modified MSCs In the studies on nephritis, the glutathione S-transferase M1(GSTM1) -producing BM-MSCs ameliorated renal pathological damage due to the inhibition of the oxidative stress-induced inflammation by reactive oxygen species removal [267]. The HGF-overexpressing BM-MSCs reduced renal fibrosis after ureteral obstruction [23], and survivin producing BM-MSCs were found beneficial in renal injury in a mouse model, probably owing to the prolonged survival and increased cytokine production by the engrafted BM-MSCs [268].…”