title: Potential of allospecific gene-engineered T cells in transplantation gene therapy: specific T cell activation determines transgene expression in vitro and in vivo.
abstract: T lymphocytes, regardless of their specificity, are considered key targets for genetic modification in the treatment of inherited or acquired human diseases. In this study, we generated Lewis T cell lines specific for Dark Agouti rat alloantigens and tested the potential of allospecific T lymphocytes as carriers of genes encoding therapeutic proteins in transplantation gene therapy. These allospecific T lymphocytes were successfully, stably transduced with enhanced green fluorescent protein (EGFP) by an Mo-MuLV-based retrovirus vector. A novel gene delivery protocol was utilized, resulting in nearly 100% EGFP-expressing T cells. This approach enabled tracking of allospecific transduced T cells in vivo and illustrates their transgene production by fluorometric determination after ex vivo isolation. Quantitation of EGFP transgene expression was used to determine the influence of T cell receptor-specific activation on transgene regulation. A strict positive correlation between activation state and expression level was detected in vitro and in vivo. The activation-induced increase in transgene expression could be blocked by interference with T cell activation signaling pathways by cyclosporin A, anti-CD4 MAb, or CTLA4-Ig. These data provide strong evidence that direct or indirect effects caused by activation-induced transcription factors are crucial in transgene upregulation. Allospecific activation in spleens, lymph nodes, and transplanted grafts can be considered as antigen-specific targeting strategy. This activation might be useful in expressing therapeutic proteins such as TGF-beta or IL-10 specific to these sites. T lymphocyte priming and activation might be prevented or altered by modification of the local microenvironments, thereby exerting a therapeutic influence on acute and chronic graft rejection processes.
authors.affiliation: Institute of Medical Immunology, Charité, Humboldt-University, Berlin, Germany.
authors.forename: M H
authors.initials: MH
authors.lastname: Hammer
authors.forename: A
authors.initials: A
authors.lastname: Flügel
authors.forename: M
authors.initials: M
authors.lastname: Seifert
authors.forename: M
authors.initials: M
authors.lastname: Lehmann
authors.forename: C
authors.initials: C
authors.lastname: Brandt
authors.forename: H D
authors.initials: HD
authors.lastname: Volk
authors.forename: T
authors.initials: T
authors.lastname: Ritter
mesh_terms: D000069594:Abatacept; D019264:Adoptive Transfer; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D060908:CTLA-4 Antigen; D017690:Cell Transplantation; D002999:Clone Cells / Q000276:immunology; D016572:Cyclosporine / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D049452:Green Fluorescent Proteins; D018796:Immunoconjugates; D007519:Isoantigens / Q000276:immunology*; D008164:Luminescent Proteins / Q000235:genetics; D008198:Lymph Nodes / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008979:Moloney murine leukemia virus / Q000235:genetics; D051381:Rats; D013154:Spleen / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000637:transplantation*; D014161:Transduction, Genetic
chemical_list: D000906:Antibodies; D015703:Antigens, CD; D000943:Antigens, Differentiation; D015704:CD4 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C556708:Ctla4 protein, rat; D018796:Immunoconjugates; D007519:Isoantigens; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D000069594:Abatacept; D016572:Cyclosporine