Inhibition of Rat Vascular Smooth Muscle Cell Proliferation In Vitro and In Vivo by Recombinant Replication-Competent Herpes Simplex Virus

Abstract

Background and Purpose-The proliferation of vascular smooth muscle cells (VSMCs) is a common feature associated with vascular proliferative disorders such as atherosclerosis and restenosis after balloon angioplasty. We examined the antiproliferative effects of recombinant replication-competent herpes simplex virus (HSV), hrR3, to proliferative VSMCs both in vitro and in vivo. Methods-Early passages of Sprague-Dawley rat VSMCs were infected with hrR3 at a low multiplicity of infection (0.01 to 1.0) to examine the in vitro cytotoxic activity of this recombinant HSV to VSMCs in a proliferative state. Sprague-Dawley rats underwent balloon dilatation injury of the left carotid artery to induce neointimal formation. The injured carotid arteries were infected with hrR3 five days after balloon injury. Two weeks after injury, the left carotid arteries were fixed, and the areas of the neointimal and medial layers were analyzed microscopically. Because the reporter Escherichia coli lacZ gene in hrR3 is expressed only in infected cells in which the virus is actively replicating, virus replication was confirmed by X-gal staining. Results-A morphometric analysis revealed that there were significant differences in the intima/media ratio between the HSV-treated group and mock-infected group (0.354Ϯ0.068 and 1.08Ϯ0.055, respectively). In the histological study (X-gal staining), positive X-gal staining was observed chiefly in the VSMCs in the medial layer just beneath the internal elastic lamina, indicating active viral replication. Conclusions-Virus-mediated cytocidal therapy using recombinant HSV vector is a promising modality for the treatment of the restenosis after balloon angioplasty. (Stroke. 1999;30:2431-2439.)

Modulation of vascular remodeling induced by a brief intraluminal exposure to the recombinant R7020 strain of Herpes simplex-1

“…For these reasons, a strategy that uses genetically engineered HSV-1 has been designed in which the agent itself is antiproliferative, abrogating the need for transgene inserts. The Herpes family of viruses are highly penetrant in vascular tissue, 42 capable of generating prolonged infection in immunocompetent hosts, 43,44 are inherently strong inhibitors of the mammalian cell cycle, 19,45,46 are potentially controllable with well-tolerated exogenous antiviral agents, 47 and have been shown to be effective in in vivo models of restenosis in the rat 42 and rabbit. 18,19,48 In humans, replication-competent HSV has been used as experimental treatment for malignant glioma.…”

Sustained inhibition of experimental neointimal hyperplasia with a genetically modified herpes simplex virus1 1Competition of interest: none.

“…HSV-1 has been extensively studied as therapy for malignant tumors of the central nervous system with a variety of genetic manipulations. 7,[11][12][13][14] Its use in vascular tissue is limited, although there are a few reports of successful use of vascular SMCs, 15 skeletal muscle cells, [16][17][18] and cardiac myocytes. 19 It was first proposed to use viruses that lack TK, ribonucleotide reductase, or glycoprotein H coding regions, which reduced viral growth in nondividing cells.…”

Gene Therapy for the Extension of Vein Graft Patency: A Review

“…A variety of vector systems have been tested experimentally including naked plasmid DNA, [82][83][84][85][86][87] DNA encapsulated within liposomes, 88-91 adenoassociated virus, 92-97 adenovirus, 48,98-126 retrovirus, 36,127 and herpesvirus. 34,[128][129][130] Vectors have been designed incorporating a myriad of transgenes including those encoding antisense cdc2 kinase and proliferating cell nuclear antigen (PCNA), [131][132][133] c-myc, 134,135 or c-myb 136 oligonucleotides, the dominant negative mutant of the ras signal transduction protein, [84][85][86]137 a mutant form of the retinoblastoma protein (Rb), 98,107,108 p21, 99,100,103 p27-16, 125 p53, 115,118 hirudin, 116 Ctype natriuretic peptide (a stimulator of membrane-bound guanylate cyclase), 105 antisense of farnesyl transferase (an enzyme required for rasprotein activation), 138 basic fibroblast growth factor (bFGF), 102,104 cyclin G1 antisense, 127 inhibitors of metalloproteinases (TIMPs), 111,114,117 endothelial nitric oxide synthase (eNOS), 87,89,112,113,120,139 thrombomodulin, 119 uteroglobin, 121 tissue factor pathway inhibitor, 124 b-adrenergic receptor kinase (bARK CT ; an inhibitor of G-protein coupled mitogenesis), 101,122 inhibitors of plasmin and urokinase binding, 106,123 antisense oligonucleotides to elongation factor-2 (E2F), 131,<...>…”

“…162 Experimental systems using herpesvirus technology have also been tested. The Herpes family of viruses are highly penetrant in vascular tissue, 128 capable of generating prolonged infection in immunocompetent hosts, 163,164 are inherently strong inhibitors of the mammalian cell cycle, 130,165,166 are potentially controllable with well-tolerated exogenous anti-viral agents, 167 and have been shown to be effective in in vivo models of restenosis in the rat 128 and rabbit. 34,80,129,130 For example, experimental external jugular vein patches with high outflow resistance treated with 10 6 pfu/mL of the R849 strain of Herpes simplex virus-1 exhibited sustained reductions in neointimal thickness up to 12 weeks following implantation.…”