Generation of regulatory gut-homing human T lymphocytes using ex vivo interleukin 10 gene transfer

Abstract

Background & Aims: Systemic treatment of Crohn's disease patients using recombinant interleukin (rlL)-10 has not resulted in significant therapeutic benefit presumably because of limited bioavailability and unexpected proinflammatory effects of high-dose rIL-10. Ex vivo gene transfer of the interleukin (IL)-10 gene to guthoming CD4+ cells may lead to improved long-term management. Methods: Peripheral blood mononuclear cells (PBMCs) were transduced with a retroviral vector containing the IL-10 and green fluorescent protein (GFP) gene or a control vector containing GFP only. Transduced CD4+ cells were sorted and maintained in culture for phenotypic and functional analysis. Results: Stimulated IL-10-GFP CD4+ cells produced significantly higher levels of IL-10 than control cells for at least 4 months. The IL-10 transgene was biologically active and decreased proliferation of IL-10-GFP CD4+ cells as well as expression of major histocompatibility class (MHC) class II, proliferation of autologous responder cells, and IL-12 production by dendritic cells (DCs). The majority of transduced CD4+ cells had a gut-homing potential because they expressed the mucosal integrin α4β7, and displayed efficient binding to MAdCAM-1-expressing cells in vitro. Conclusions: Transduction of peripheral blood CD4+ lymphocytes with IL-10 results in a regulatory phenotype. The use of regulatory gut-homing human CD4+ cells may provide a novel approach to local delivery of immunomodulatory signals to the intestine in Crohn's disease.