title: Visualizing the course of antigen-specific CD8 and CD4 T cell responses to a growing tumor.
abstract: Spontaneous tumors frequently express antigens that can be recognized by the immune system but nevertheless manage to evade immune surveillance. To better understand the mechanism of evasion, we followed CD8 and CD4 T cells reacting against a subcutaneously growing tumor, modified to express influenza hemagglutinin (HA) as surrogate tumor antigen. Adoptive transfer of 8,000 antigen-specific CD8 T cells was sufficient to protect against challenge with 1x10(6) tumor cells, while larger numbers of T cells rejected established tumors. HA-specific CD4 T cells could not reject tumors on their own but helped rejection by CD8 T cells. Rejection of the tumor coincided with prolonged survival of expanded antigen-specific CD8 and CD4 T cells, while a failing anti-tumor response was accompanied by transient expansion followed by rapid elimination of antigen-specific T cells. Thus, a highly immunogenic tumor can evade immune surveillance because of an insufficient number of tumor-specific T cells and antigen overload, resulting in exhaustion of the immune response. In this scenario, adoptive immunotherapy rather than vaccination promises successful treatment.
authors.affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Boston, MA 02115, USA.
authors.forename: Ludger
authors.initials: L
authors.lastname: Klein
authors.forename: Lydie
authors.initials: L
authors.lastname: Trautman
authors.forename: Stelios
authors.initials: S
authors.lastname: Psarras
authors.forename: Silke
authors.initials: S
authors.lastname: Schnell
authors.forename: Anja
authors.initials: A
authors.lastname: Siermann
authors.forename: Roland
authors.initials: R
authors.lastname: Liblau
authors.forename: Harald
authors.initials: H
authors.lastname: von Boehmer
authors.forename: Khashayarsha
authors.initials: K
authors.lastname: Khazaie
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D006084:Graft Rejection; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000276:immunology* / Q000473:pathology
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus