title: Robust expansion of viral antigen-specific CD4+ and CD8+ T cells for adoptive T cell therapy using gene-modified activated T cells as antigen presenting cells.
abstract: Cytomegalovirus (CMV) reactivation after stem cell transplantation can be treated with CMV-specific T cells, but current in vitro techniques using dendritic cells as antigen-presenting cells are time-consuming and expensive. To simplify the production of clinical grade CMV-specific T cells, we evaluated gene-modified activated T cells [antigen presenting T cells (T-APCs)] as a reliable and easily produced source of APCs to boost CD4+ and CD8+ T-cell responses against the immunodominant CMV antigen pp65. T-APCs expressing the full-length immunodominant CMV pp65 gene were used to stimulate the expansion of autologous T cells. After 10 to 14 days, the T cell lines were tested for antigen specificity by using the flow cytometric intracellular detection of interferon-gamma after stimulation for 6 hours with a pp65 peptide library of 15-mers, overlapping by 11 amino acids. Under optimal conditions, this technique induced a median 766-fold and a 652-fold expansion of pp65-specific CD4+ and CD8+ responder cells, respectively, in 15 T cell lines. In 13 of 15 T cell lines, over 10 antigen-specific CD4+ plus CD8+ T cells were generated starting with only 5x10 peripheral blood mononuclear cells, representing an over 3-log increase. These data indicate that T-APCs efficiently boost pp65-specific CD4+ and CD8+ T cell numbers to clinically useful levels. The approach has the advantage of using a single leukocyte collection from the donor to generate large numbers of CMV-specific T cells within a total 3-week culture period using only one stimulation of antigen.
authors.affiliation: Stem Cell Allogeneic Transplantation Section, Hematology Branch, NHLBI, NIH, 10 Center Drive, Bethesda, MD 20892-1202, USA. melenhoj@nhlbi.nih.gov
authors.forename: Jan Joseph
authors.initials: JJ
authors.lastname: Melenhorst
authors.forename: Scott Robert
authors.initials: SR
authors.lastname: Solomon
authors.forename: Aarthi
authors.initials: A
authors.lastname: Shenoy
authors.forename: Nancy Fern
authors.initials: NF
authors.lastname: Hensel
authors.forename: John Philip
authors.initials: JP
authors.lastname: McCoy
authors.forename: Keyvan
authors.initials: K
authors.lastname: Keyvanfar
authors.forename: Austin John
authors.initials: AJ
authors.lastname: Barrett
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology*; D000956:Antigens, Viral / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000097:blood / Q000628:therapy; D006801:Humans; D016219:Immunotherapy, Adoptive; D008213:Lymphocyte Activation; D010750:Phosphoproteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D014161:Transduction, Genetic; D014763:Viral Matrix Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa