Amelioration of Chronic and Spontaneous Intestinal Inflammation with an Antisense Oligonucleotide (ISIS 9125) to Intracellular Adhesion Molecule-1 in the HLA-B27/ 2 Microglobulin Transgenic Rat Model

Adhesion molecules are known to be an important part of leukocyte migration and extravasation in both homeostatic and inflammatory conditions. Intracellular adhesion molecule-1 (ICAM-1 or CD54) is constitutively expressed on endothelial cells and is up-regulated during acute and chronic inflammation. We investigated the efficacy and consequences of interfering with CD54 after administration of an antisense oligonucleotide to ICAM-1 (CD54) in the transgenic HLA-B27/ 2 microglobulin rat model. One hundred percent of the HLA-B27 transgene animals will spontaneously develop chronic inflammation (some more severely than others) in the gastric mucosa, cecum, and colon. We carried out two studies, i.p. injection and rectal administration of antisense. Following i.p. and rectal treatment, there were significant decreases in colonic mucosal wall thickness, histologic inflammation, CD54 expression in the colon and peripheral blood, and the percentage of colon weight per end body weight. Furthermore, decreased expression of CD49d, CD18, and tumor necrosis factorwas observed in antisense treated rats. Therefore, the HLA-B27 transgenic model of spontaneous and chronic inflammatory bowel disease, which has increased expression of adhesion molecules, responds to both routes of administration of ICAM-1 antisense oligonucleotides. These studies support the regulatory role of adhesion molecules in chronic intestinal inflammation, the need for an understanding of how the route of drug delivery can alter the dose and area affected, and finally the role of antisense oligonucleotides as a therapeutic modality in chronic spontaneous inflammatory bowel diseases. The inflammatory bowel diseases (IBD), Crohn’s disease and ulcerative colitis are immunoregulatory disorders of the intestinal tract. They are a prolonged and inappropriately intense reaction to an undefined antigenic stimulation, which is primarily T-cell regulated (Elson and McCabe, 1995). Several animal models have been developed to study IBD. In the past, many of these models have involved the mechanical induction of colitis with dior trinitrobenzene sulfonic acid, dextran sulfate sodium (DSS), or acetic acid (Yamada et al., 1992; Wong et al., 1995; Hamamoto et al., 1999; Yoshida et al., 2001). More recently, gene knock-out, transgenics, leaky gut, and adoptive transfer rodent models have been created that develop a spontaneous and chronic form of inflammation involving the colon and other parts of the intestinal tract (MacDonald et al., 2000; Neurath, 2000). The recruitment and activation of inflammatory cells as a result of proinflammatory cytokine production (interleukin12, interferon, and TNF), with excess production of matrix-degrading enzymes and up-regulation of a spectrum of cell adhesion molecules, including intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule-1, selectins, and integrins, on mucosal endothelial and lamina propria mononuclear cells, are important immunological features of IBD (Jones et al., 1995; MacDonald et al., 2000; Yoshida et al., 2001). Our group and others have found a difference in the expression of adhesion molecules in Crohn’s disease compared with ulcerative colitis (Hemler, 1988; Malizia et al., 1991; Yacyshyn et al., 1994). Specifically, others have studied the role of ICAMs in gut inflammation (Wong et al., 1995; Hamamoto et al., 1999; Sans et al., 1999; Bendjelloul et al., 2000). This work was supported by ISIS Pharmaceuticals. Article, publication date, and citation information can be found at http://jpet.aspetjournals.org. DOI: 10.1124/jpet.102.036053. ABBREVIATIONS: IBD, inflammatory bowel disease; DSS, dextran sulfate sodium; TNF, tumor necrosis factor; ICAM, intercellular adhesion molecule; RT-PCR, reverse transcription-polymerase chain reaction; TGF, T-cell growth factor; SIS, severity of inflammation score; PBL, peripheral blood lymphocyte. 0022-3565/02/3023-908–917$7.00 THE JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS Vol. 302, No. 3 Copyright © 2002 by The American Society for Pharmacology and Experimental Therapeutics 36053/1005701 JPET 302:908–917, 2002 Printed in U.S.A. 908 at A PE T Jornals on A uust 0, 2017 jpet.asjournals.org D ow nladed from To evaluate the role of adhesion molecules in intestinal inflammation, we used the HLA-B27 / 2 microglobulin transgenic rat model. These rats, like humans, have a genetic component to their intestinal pathology (Hammer et al., 1990). In support of this fact is that HLA-B27 littermates do not develop inflammatory diseases (Hammer et al., 1990). Following one theory, IBD is associated with normal bacterial flora; it appears that bacteria trigger HLA-B27 transgenic rat intestinal inflammation because germ-free rats do not develop disease (Taurog et al., 1994; Rath et al., 1996). The profile of cytokine, biochemical markers and histology in HLA-B27 transgenic rats exposed to enteric bacteria, is similar to those found in human IBD and is consistent with T cell, NK cell, and macrophage-mediated inflammation (Taurog et al., 1994; Rath et al., 1996). We sought to study the effect of an antisense oligonucleotide to ICAM-1 (ISIS 9125) in a placebo-controlled study in the HLA-B27 transgenic rat model of gut inflammation. In the past, most investigators studying ICAM-1 involvement in inflammation used intravenous, intraperitoneal, and colonic administration of monoclonal antibodies that bound to and blocked the effect of the surface protein ICAM-1 and its interactions taken out with cells (Wong et al., 1995; Hamamoto et al., 1999; Sans et al., 1999). i.p. and rectal administrations were used to determine whether blockade or dampening of ICAM-1 protein production could affect chronic inflammation using DNA-specific antisense for the 3 portion of the mRNA of ICAM-1. Antisense molecules have been investigated in animal models of sepsis, neoplasm, organ transplantation, and inflammatory disease (Neurath et al., 1996). The study of antisense to ICAM-1 in the HLA-B27 transgenic rat determined the effects of specific intervention of CD54 on adhesion molecules and inflammation. Materials and Methods