title: Modeling the CD8+ T effector to memory transition in adoptive T-cell antitumor immunotherapy.
abstract: Adoptive T-cell therapy with CD8(+) CTLs is often characterized by poor persistence of the transferred T cells and limited effector responses. Improved persistence and therapeutic efficacy have been noted when antigen-activated CD8(+) T cells express properties of memory cells. The current study was undertaken to more precisely characterize the development of memory-like CD8(+) T cells from short-term CTLs in vitro and upon transfer in vivo, including their antitumor activity. Ovalbumin (OVA)-specific OT-I CTLs acquired phenotypic and functional properties of memory cells 2 to 3 days later either by lowering the concentration of antigen to a level that does not support primary responses and providing a survival signal through transgenic Bcl-2 in vitro or simply by transferring early day 3 CTLs to antigen-free lymphoid-replete mice. In lymphoid-replete mice, established OVA-expressing E.G7 tumor was rejected by short-term CTLs that simultaneously acquired memory-like properties in secondary lymphoid tissues, where tumor antigen level remained low. Collectively, these data indicate that CTLs readily converted to memory-like cells upon lowering antigen to a concentration that selectively supports memory responses and suggest that such conversion predicts successful adoptive immunotherapy.
authors.affiliation: Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33101, USA.
authors.forename: Cleo E
authors.initials: CE
authors.lastname: Rolle
authors.forename: Roberto
authors.initials: R
authors.lastname: Carrio
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Malek
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002470:Cell Survival / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D019254:Genes, bcl-2; D006801:Humans; D007156:Immunologic Memory; D007167:Immunotherapy / Q000379:methods*; D016219:Immunotherapy, Adoptive; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009369:Neoplasms / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*