title: Adoptively transferred tumor-specific T cells stimulated ex vivo using herpes simplex virus amplicons encoding 4-1BBL persist in the host and show antitumor activity in vivo.
abstract: 4-1BB is a T-cell costimulatory receptor which binds its ligand 4-1BBL, resulting in prolonged T cell survival. We studied the antitumor effects of adoptively transferred tumor-specific T cells expanded ex vivo using tumors transduced with herpes simplex virus (HSV) amplicons expressing 4-1BBL as a direct source of antigen and costimulation. We constructed HSV amplicons encoding either the 4-1BBL (HSV.4-1BBL) or B7.1 (HSV.B7.1) costimulatory ligands. Lewis lung carcinoma cells expressing ovalbumin (LLC/OVA) were transduced with HSV.4-1BBL, HSV.B7.1, or control HSV amplicons and used to stimulate GFP+ OVA-specific CD8+ T cells (OT-1/GFP) ex vivo. Naive or ex vivo stimulated OT-1/GFP cells were adoptively transferred into LLC/OVA tumor-bearing mice. Higher percentages of OT-1/GFP cells were seen in the peripheral blood, spleen, and tumor bed of the HSV.4-1BBL-stimulated OT-1/GFP group compared with all other experimental groups. OT-1 cells identified within the tumor bed and draining lymph nodes of the HSV.4-1BBL-stimulated OT-1 group showed enhanced bromodeoxyuridine (BrdUrd) incorporation, suggesting ongoing expansion in vivo. Mice receiving HSV.4-1BBL-stimulated OT-1/GFP had significantly decreased tumor volumes compared with untreated mice (P<0.001) or to mice receiving naive OT-1/GFP (P<0.001). Transfer of HSV.B7.1-stimulated OT-1/GFP did not protect mice from tumor. Mice that received HSV.4-1BBL-stimulated OT-1/GFP exhibited increased cytolytic activity against LLC/OVA and higher percentages of Ly-6C+ OT-1/GFP in the spleen and tumor bed compared with controls. Tumor-specific T cells stimulated ex vivo using tumor transduced with HSV.4-1BBL expand in vivo following adoptive transfer, resulting in tumor eradication and the generation of tumor-specific CD44+Ly-6C+CD62L- effector memory T cells.
authors.affiliation: Department of Microbiology and Immunology, University of Miami Miller School of Medicine, and University of Miami Sylvester Comprehensive Cancer Center, Miami, Florida 33136, USA.
authors.forename: Kyung H
authors.initials: KH
authors.lastname: Yi
authors.forename: Hovav
authors.initials: H
authors.lastname: Nechushtan
authors.forename: William J
authors.initials: WJ
authors.lastname: Bowers
authors.forename: Gail R
authors.initials: GR
authors.lastname: Walker
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dien G
authors.initials: DG
authors.lastname: Pham
authors.forename: Eckhard R
authors.initials: ER
authors.lastname: Podack
authors.forename: Howard J
authors.initials: HJ
authors.lastname: Federoff
authors.forename: Khaled A
authors.initials: KA
authors.lastname: Tolba
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Rosenblatt
mesh_terms: D053330:4-1BB Ligand / Q000235:genetics / Q000276:immunology*; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D018827:Carcinoma, Lewis Lung / Q000235:genetics / Q000276:immunology* / Q000628:therapy* / Q000821:virology; D005822:Genetic Vectors / Q000235:genetics; D016219:Immunotherapy, Adoptive / Q000379:methods*; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D018139:Simplexvirus / Q000235:genetics* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection
chemical_list: D053330:4-1BB Ligand