Inflammation and Immune Response of Intra-Articular Serotype 2 Adeno-Associated Virus or Adenovirus Vectors in a Large Animal Model

Akikazu Ishihara,Jeffrey S Bartlett,Alicia L Bertone

doi:10.1155/2012/735472

Akikazu Ishihara, Jeffrey S Bartlett + Show 1 more

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https://doi.org/10.1155/2012/735472

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Abstract

Intra-articular gene therapy has potential for the treatment of osteoarthritis and rheumatoid arthritis. To quantify in vitro relative gene transduction, equine chondrocytes and synovial cells were treated with adenovirus vectors (Ad), serotype 2 adeno-associated virus vectors (rAAV2), or self-complementary (sc) AAV2 vectors carrying green fluorescent protein (GFP). Using 6 horses, bilateral metacarpophalangeal joints were injected with Ad, rAAV2, or scAAV2 vectors carrying GFP genes to assess the in vivo joint inflammation and neutralizing antibody (NAb) titer in serum and joint fluid. In vitro, the greater transduction efficiency and sustained gene expression were achieved by scAAV2 compared to rAAV2 in equine chondrocytes and synovial cells. In vivo, AAV2 demonstrated less joint inflammation than Ad, but similar NAb titer. The scAAV2 vectors can induce superior gene transduction than rAAV2 in articular cells, and both rAAV2 and scAAV2 vectors were showed to be safer for intra-articular use than Ad vectors.

Highlights

In elderly people, joint disorders including osteoarthritis and rheumatoid arthritis remain major causes of mobility loss [1]
We hypothesized that self-complementary AAV2 (scAAV2) vectors would show accelerated and greater gene transduction in vitro compared to recombinant AAV2 (rAAV2) and induce less inflammation and immune response in vivo compared to Ad vectors
Particle count of Ad vectors was determined by optical density at 260 nm, and particle titers of rAAV2 and scAAV2 vectors were determined by DNase-resistant particle (DRP) values using real-time PCR assay as described previously [16]

Summary

Introduction

Joint disorders including osteoarthritis and rheumatoid arthritis remain major causes of mobility loss [1]. AAV2 vectors have been modified to package self-complementary DNA, capable of bypassing the rate-limiting step of secondstrand synthesis in order to accelerate and improve the transduction efficiency [12, 13]. Such self-complementary AAV2 (scAAV2) vectors have been shown to effectively transduce chondrocytes and synovial cells [14] and cartilage explants [12] in vitro, and induce superior transgene expression in cartilage and synovium tissues after injection of 5 × 1011 particles in vivo in rodent models [3]. Intraarticular administration of scAAV2 vectors has potential for future clinical application, but the inflammation and Arthritis immune reactions, cell tropism, and application to larger joints as in people have not been directly compared among rAAV2, scAAV2, or Ad vectors in vivo

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