title: Comparison of AAV/IL-7 autocrine (T cell) versus paracrine (DC) gene delivery for enhancing CTL stimulation and function.
abstract: Adoptive transfer of antigen-specific cytotoxic T lymphocyte (CTL) into patients holds promise in treating cancer. Such anti-cancer CTL are stimulated by professional antigen-presenting dendritic cells (DC). We hypothesize the gene delivery of various Th1-response cytokines, such as interleukin 7 (IL-7), should further enhance CTL stimulation and activity. However, the issue as to which cell type, DC (paracrine) or the T cell (autocrine), should express a particular Th1 cytokine gene for optimal CTL stimulation has never been addressed. We used adeno-associated virus-2 (AAV) to compare delivery of IL-7 and IL-2 genes into DC or T cells and to exogenous commercial cytokines for generating robust carcinoembryonic antigen (CEA)-specific CTL. AAV/IL-7 transduction of T cells (autocrine delivery) generated CTL with the highest killing capability. Consistent with this, AAV/IL-7 delivery generated T cell populations with the highest proliferation, highest interferon gamma expression, highest CD8(+):CD4(+) ratio, highest CD8(+), CD69(+) levels, and lowest CD4(+), CD25(+) (Treg) levels. These data are consistent with higher killing by the AAV/IL-7-altered CTL. These data strongly suggest that IL-7 autocrine gene delivery is optimal for CTL generation. These data also suggest Th1 cytokine autocrine versus paracrine delivery is an important issue for immuno-gene therapy and uncovers new questions into cytokine mechanism of action.
authors.affiliation: Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, 72205, USA.
authors.forename: Chang-Xuan
authors.initials: CX
authors.lastname: You
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Shi
authors.forename: Maohua
authors.initials: M
authors.lastname: Cao
authors.forename: Rong-Cheng
authors.initials: RC
authors.lastname: Luo
authors.forename: Paul L
authors.initials: PL
authors.lastname: Hermonat
mesh_terms: D002272:Carcinoembryonic Antigen / Q000235:genetics / Q000276:immunology; D002469:Cell Separation; D003713:Dendritic Cells / Q000276:immunology*; D000229:Dependovirus; D005434:Flow Cytometry; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D007376:Interleukin-2 / Q000235:genetics; D015851:Interleukin-7 / Q000235:genetics* / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014161:Transduction, Genetic
chemical_list: D002272:Carcinoembryonic Antigen; D007376:Interleukin-2; D015851:Interleukin-7