title: Functional memory CD8+ T cells can be generated in vivo without evident T help.
abstract: Synthetic cytotoxic T cell (CTL) epitope peptides provide an effective and safe means of vaccination against cancers and viruses, as these peptides can induce specific CD8+ effector T cells in vivo. However, the effector CD8+ T cells induced by the minimal CTL epitope peptides do not last past about 3 weeks after the induction and no functional memory CD8+ T cells are generated. It is held that simultaneous induction of CD4+ T cells by incorporating peptides containing T-helper epitopes in the vaccine at the time of primary vaccination are necessary for the induction of long-lived functional memory CD8+ T cells. We now report that, surprisingly, incorporation of medium length (>20 AA) peptides devoid of detectable T-helper epitopes in a minimal CTL epitope-based vaccine can also induce long-lasting functional tumour antigen specific memory CD8+ T cells that are capable of promoting protection against tumour challenge. This observation may have implications for the formulation of therapeutic anti-cancer and anti-virus peptide vaccines where a strong induction of CD4 T help would be undesirable.
authors.affiliation: Centre for Immunology and Cancer Research, The University of Queensland, Princess Alexandra Hospital, Brisbane, QLD 4102, Australia.
authors.forename: Melanie R
authors.initials: MR
authors.lastname: Andrews
authors.forename: Tania
authors.initials: T
authors.lastname: Peters
authors.forename: Vithagna
authors.initials: V
authors.lastname: Khammanivong
authors.forename: Graham R
authors.initials: GR
authors.lastname: Leggatt
authors.forename: Ian H
authors.initials: IH
authors.lastname: Frazer
authors.forename: Germain J P
authors.initials: GJ
authors.lastname: Fernando
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D018984:Epitopes, T-Lymphocyte / Q000737:chemistry / Q000276:immunology*; D007156:Immunologic Memory / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010455:Peptides / Q000009:adverse effects / Q000276:immunology / Q000494:pharmacology; D013602:T-Lymphocytes, Cytotoxic / Q000737:chemistry / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014611:Vaccination
chemical_list: D018984:Epitopes, T-Lymphocyte; D010455:Peptides