Mature dendritic cells pulsed with freeze-thaw cell lysates define an effective in vitro vaccine designed to elicit EBV-specific CD4(+) and CD8(+) T lymphocyte responses.
Immunotherapy trials targeting the induction of tumor-reactive T-cell responses in cancer patients appear to hold significant promise. Because nonmutated lineage-specific antigens and mutated idiotypic antigens may be coexpressed by tumor cells, the use of autologous tumor material to promote the broadest range of antitumor T-cell specificities has significant clinical potential in cancer vaccination trials. As a model for vaccination in the cancer setting, we chose to analyze the promotion of T-cell responses against Epstein-Barr virus (EBV)-transformed B-lymphoblastoid cell line (B-LCL)-derived antigens in vitro. A series of bulk antigenic formats (freeze-thaw lysate, trifluoroacetic acid lysate, extracted membranes, affinity-purified MHC class I- and class II-presented peptides, acid-eluted peptides) prepared from EBV B-LCLs were tested for their ability to stimulate EBV B-LCL-reactive CD4(+) and CD8(+) T lymphocytes in vitro when pulsed onto autologous dendritic cells (DCs). DC presentation of freeze-thaw lysate material derived from (either autologous or allogeneic) EBV B-LCLs with an Mr of 10 kd or larger stimulated optimal anti-EBV B-LCL responsiveness from freshly isolated CD4(+) and CD8(+) peripheral blood T cells. These in vivo "memory" T-cell responses were observed only in EBV-seropositive donors. CD4(+) T-cell responses to lysate-pulsed DCs were Th1 type (ie, strong interferon-gamma and weak interleukin-5 responses). While CD8(+) T-cell responses were also observed in interferon-gamma Elispot assays and in cytotoxicity assays, these responses were of low frequency unless the DC stimulators were induced to "mature" after being fed with tumor lysates. Optimal-length, naturally processed, and MHC class I- or class II-presented tumor peptides were comparatively poorly immunogenic in this model system. (Blood. 2000;96:1857-1864)
Herr
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W
Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Ranieri
E
E
Olson
W
W
Zarour
H
H
Gesualdo
L
L
Storkus
W J
WJ
D000951:Antigens, Neoplasm / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology*; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D015848:Interleukin-5 / Q000378:metabolism; D009000:Monocytes / Q000166:cytology / Q000276:immunology; D013347:Subcellular Fractions / Q000276:immunology
D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D015848:Interleukin-5; D007371:Interferon-gamma