title: TNF-mediated toxicity after massive induction of specific CD8+ T cells following immunization of mice with a tumor-specific peptide.
abstract: We immunized mice with antigenic peptide P815E, which is presented by H-2K(d) and recognized by tumor-specific CTL raised against P815 tumor cells. This peptide is encoded by the ubiquitously expressed gene MsrA and carries a mutated residue conferring tumor specificity. Unexpectedly, we observed a severe toxicity occurring in the early hours after the third injection, resulting in the death of most mice within 24 h. The toxic syndrome was reminiscent of TNF-induced shock, and the sera of ill mice contained high levels of TNF. Toxicity was prevented by injection of neutralizing anti-TNF Abs, confirming the involvement of TNF. Depletion of CD8+ T cells could also prevent toxicity, and ex vivo experiments confirmed that CD8+ lymphocytes were the major cellular source of TNF in immunized mice. Tetramer analysis of the lymphocytes of immunized mice indicated a massive expansion of P815E-specific T cells, up to >60% of circulating CD8+ lymphocytes. A similar toxicity was observed after massive expansion of specific CD8+ T cells following immunization with another P815 peptide, which is encoded by gene P1A and was injected in a form covalently linked to an immunostimulatory peptide derived from IL-1. We conclude that the toxicity is caused by specific CD8+ lymphocytes, which are extensively amplified by peptide immunization in a QS21-based adjuvant and produce toxic levels of TNF upon further stimulation with the peptide. Our results suggest that immunotherapy trials involving new peptides should be pursued with caution and should include a careful monitoring of the T cell response.
authors.affiliation: Ludwig Institute for Cancer Research and Cellular Genetics Unit, Université de Louvain, Brussels, Belgium.
authors.forename: Janine
authors.initials: J
authors.lastname: Bilsborough
authors.forename: Catherine
authors.initials: C
authors.lastname: Uyttenhove
authors.forename: Didier
authors.initials: D
authors.lastname: Colau
authors.forename: Philippe
authors.initials: P
authors.lastname: Bousso
authors.forename: Claude
authors.initials: C
authors.lastname: Libert
authors.forename: Birgit
authors.initials: B
authors.lastname: Weynand
authors.forename: Thierry
authors.initials: T
authors.lastname: Boon
authors.forename: Benoit J
authors.initials: BJ
authors.lastname: van den Eynde
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000951:Antigens, Neoplasm / Q000008:administration & dosage / Q000276:immunology* / Q000633:toxicity; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D007279:Injections, Subcutaneous; D008213:Lymphocyte Activation / Q000187:drug effects; D012515:Mast-Cell Sarcoma / Q000276:immunology; D051379:Mice; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D010455:Peptides / Q000008:administration & dosage / Q000276:immunology* / Q000633:toxicity; D012772:Shock, Septic / Q000276:immunology / Q000401:mortality; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000502:physiology* / Q000633:toxicity*
chemical_list: D000951:Antigens, Neoplasm; D018984:Epitopes, T-Lymphocyte; D010455:Peptides; D014409:Tumor Necrosis Factor-alpha