The Prevention and Treatment of Murine Colitis Using Gene Therapy with Adenoviral Vectors Encoding IL-10

Abstract

IL-10-deficient (IL-10−/−) mice develop colitis with many similarities to Crohn’s disease. Daily IL-10 injections have a short systemic half-life and are unable to induce complete remission in IL-10−/− mice with established disease. In this paper, we investigate the duration, potency, and immunogenicity of gene therapy using an adenoviral vector encoding murine IL-10 (AdvmuIL-10). A single systemic injection of AdvmuIL-10 was sufficient not only to prevent the onset of colitis for at least 10 wk but also to induce clinical and histological remission in mice with established disease. In addition, AdvmuIL-10 diminished the systemic manifestations of disease, including elevated acute-phase proteins, as well as the local consequences of inflammation such as raised stool IL-1β concentrations. Both IL-10 protein and the effects of secreted IL-10 were detectable for 10 wk after AdvmuIL-10 injection. Furthermore, the immunoregulatory effect of a single AdvmuIL-10 injection was manifest both by a reduction in TNF-α, IFN-γ, and RANTES release from stimulated splenocyte cultures, and also by a change in the proportion of CD45RBhigh/low lymphocytes in the spleen compared with control mice. The delivery of AdvmuIL-10 resulted in a significantly diminished host antiadenoviral response compared with control adenoviral vectors. Thus, gene therapy strategies using adenoviral vectors encoding immunoregulatory and antiinflammatory cytokines may prove to be a potent approach for the treatment of chronic inflammatory disease. Antiinflammatory cytokine expression protects against immune responses directed at gene vectors.

IL-10 gene therapy prevents TNBS-induced colitis

“…This agrees with our previous observation that serum mIL-10 levels are raised for approximately 1 week after AdvmuIL-10 administration in IL-10 À/À mice. 23 Previous studies have demonstrated low-level colonic transgene expression after systemic adenoviral vector delivery; 18,19 however, there was no difference in the levels of IL-10 detected in colon homogenates from AdvmuIL-10 or control treated mice with TNBS colitis.…”

“…29 Finally, in this study we did not assess the host anti-adenovirus response, which may shorten the duration of transgenic IL-10 expression. However, in other animal models, we 23 and others 30,31 have shown that the delivery of immunoregulatory genes is able to suppress the development of antiadenoviral antibodies resulting in extended transgene expression.…”

“…23,27 Therefore, stools collected upon sacrifice were assayed for these cytokines by ELISA ( Figure 3). As expected, IL-1b and TNFR-II levels were high in TNBS mice treated with PBS (731 7 348 and 441 7 90 pg/ml, respectively) and undetectable in all saline control mice.…”

“…The reduction in mucosal inflammation seen with AdvmuIL-10 therapy in TNBS colitis (quantified as a 34% decrease in histological score) is not as impressive as the reduction seen in IL-10 À/À mice. 23 However, this is not surprising given the breadth of the inflammatory cascade that is activated by TNBS administration, compared to the isolated defect in IL-10 À/À mice. In fact, the results compare favourably with other therapeutic strategies reported in mice with TNBS colitis; for example, IL-18 binding protein (42% fall in histological score) 26 and the chemokine receptor antagonist Met-RANTES (57% fall in histological score).…”

“…[20][21][22] Finally, we have recently demonstrated the efficacy of adenovirus-mediated IL-10 gene transfer in the treatment of established colitis in IL-10 À/À mice. 23 In the present study, we have investigated the therapeutic efficacy of mIL-10 adenovirus-mediated (AdvmuIL-10) gene transfer in murine 2,4,6-trinitrobenzene sulphonic acid (TNBS) colitis, which has many histological and immunological similarities to Crohn's disease, and is also relatively unresponsive to daily systemic injections of recombinant IL-10. 24 Intra-rectal TNBS administration induces a transmural colitis, which results from the rapid induction of an IL-12-driven, Th1-mediated response that is not balanced by the prompt appearance of a regulatory response.…”