Direct gene delivery to synovium: An evaluation of potential vectors in vitro and in vivo

Abstract

Objective. To assess the abilities of various vectors to transfer genes to the synovial lining of joints.Methods. Vectors derived from retrovirus, adenovirus, and herpes simplex virus as well as cationic liposomes and naked plasmid DNA were evaluated. Each construct contained the lac Z marker gene; and one retroviral construct, and one plasmid also contained a gene encoding human interleukin-1 receptor antagonist. Gene expression was under the control of the human cytomegalovirus promoter in all vectors except the retrovirus, where the endogenous 5' long terminal repeat was retained as the promoter. Cultures of rabbit synovial fibroblasts were exposed to these vectors and stained with X-gal to identify lac Z+ cells. Vectors were then injected directly into rabbits' knee joints, and gene transfer and expression were assessed by X-gal staining and polymerase chain reaction (PCR).Results. Adenovirus was a highly effective vector both in vitro and in vivo, with lac Z gene expression persisting for at least 28 days. However, an inflammatory response was noted in vivo. Cells infected in vitro and in vivo with herpes simplex virus also expressed the loc 2 gene at high levels, but expression was limited by cytotoxicity. Retroviruses, in contrast, were effective --~ _-

Intra-articular delivery of a herpes simplex virus IL-1Ra gene vector reduces inflammation in a rabbit model of arthritis

“…Initial studies by Nita et al 8 indicated that first-generation HSV vectors were efficient at transferring exogenous genes to the synovial lining of the joint, but also produced substantial inflammatory and cytotoxic effects following intra-articular delivery. Recently, second-generation HSV vectors have been created which are considerably less toxic than the first-generation vectors when tested in a number of cell types.…”

“…In an effort to devise a more practical strategy, several laboratories have been exploring the use of direct, in vivo gene delivery to the joint. [7][8][9][10][11] A number of viral and nonviral vectors have been found to deliver DNA to synovial cells efficiently. We have recently shown that direct intra-articular injection of adenoviral vectors encoding soluble receptors for interleukin-1 (IL-1) and tumor necrosis factor ␣ (TNF␣) were able to block effectively many of the pathologies associated with antigen-induced arthritis in rabbits.…”

“…Finally, preliminary studies with a first-generation vector have shown that HSV is highly infectious for synovial cells in culture and in experimental animals. 8 During infection with wild-type HSV, a viral tegument polypeptide, VP16, activates transcription of five immediate-early (IE) genes encoding infected cell polypeptide (ICP) 0, 4, 22, 27 and 47. 15,16 Expression of these IE genes is essential for regulating the expression of subsequent early and late viral genes necessary for HSV replication.…”

Immuno- and genetic therapy in autoimmune diseases

“…182 The inflamed synovium has been directly targeted in vivo with retrovirus, adenovirus, plasmids complexed with cationic lipids and DNA oligonucleotides serving as decoys for NFkB. [189][190][191][192] Interestingly, in vitro infection of rheumatoid synovial cells with adenovirus expressing an inhibitor of NFkB (IkB␣) has shown that T cells, fibroblasts and macrophages could be infected and was capable of down-regulating expression of inflammatory cytokines whilst sparing the expression of protective cytokines. 193 These findings are of interest as normally T cells or macrophages are non-permissive to adenoviral infection and indicates that these cells exist in the rheumatoid joint in a different physiological state than normal cells.…”

Cationic lipids are essential for gene delivery mediated by intravenous administration of lipoplexes

“…Based on these data, Song et al suggested that extracellular DNA released from the lipoplex is the transfectionally active agent, and that the cationic lipid component serves only to increase pulmonary retention of DNA following systemic administration. 10 Given that naked plasmid DNA is capable of transfecting striated muscle 11,12 , the thyroid gland 13 , the liver 14 , the lung 15 , solid tumors 16 and synovial tissue 17 , we found Song's observations intriguing and believed the hypothesis to be an important conjecture. If the proposal is correct, then any sustained release system for DNA should mediate transfection in the lung.…”