title: Synthetic CD4+ T cell-targeted antigen-presenting cells elicit protective antitumor responses.
abstract: CD4(+) helper T cells are critical for protective immune responses and yet suboptimally primed in response to tumors. Cell-based vaccination strategies are under evaluation in clinical trials but limited by the need to derive antigen-presenting cells (APC) from patients or compatible healthy donors. To overcome these limitations, we developed CD4(+) T cell-targeted synthetic microbead-based artificial APC (aAPC) and used them to activate CD4(+) T lymphocytes specific for a tumor-associated model antigen (Ag) directly from the naive repertoire. In vitro, aAPC specifically primed Ag-specific CD4(+) T cells that were activated to express high levels of CD44, produced mainly interleukin 2, and could differentiate into Th1-like or Th2-like cells in combination with polarizing cytokines. I.v. administration of aAPC led to Ag-specific CD4(+) T-cell activation and proliferation in secondary lymphoid organs, conferred partial protection against subcutaneous tumors, and prevented the establishment of lung metastasis. Taken together, our data support the use of cell-free, synthetic aAPC as a specific and versatile alternative to expand peptide-specific CD4(+) T cells in adoptive and active immunotherapy.
authors.affiliation: Cancer Immunotherapy and Gene Therapy Program, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Caserta
authors.forename: Patrizia
authors.initials: P
authors.lastname: Alessi
authors.forename: Jlenia
authors.initials: J
authors.lastname: Guarnerio
authors.forename: Veronica
authors.initials: V
authors.lastname: Basso
authors.forename: Anna
authors.initials: A
authors.lastname: Mondino
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000637:transplantation; D000953:Antigens, Protozoan / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D019496:Cancer Vaccines / Q000627:therapeutic use; D004331:Drosophila melanogaster / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000737:chemistry / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009369:Neoplasms / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000953:Antigens, Protozoan; D019496:Cancer Vaccines; D000949:Histocompatibility Antigens Class II; D015800:Protozoan Proteins; C093139:LACK antigen, Leishmania