title: Modified tumour antigen-encoding mRNA facilitates the analysis of naturally occurring and vaccine-induced CD4 and CD8 T cells in cancer patients.
abstract: The development of effective anti-cancer vaccines requires precise assessment of vaccine-induced immunity. This is often hampered by low ex vivo frequencies of antigen-specific T cells and limited defined epitopes. This study investigates the applicability of modified, in vitro-transcribed mRNA encoding a therapeutically relevant tumour antigen to analyse T cell responses in cancer patients. In this study transfection of antigen presenting cells, by mRNA encoding the tumour antigen NY-ESO-1, was optimised and applied to address spontaneous and vaccine-induced T cell responses in cancer patients. Memory CD8+ T cells from lung cancer patients having detectable humoral immune responses directed towards NY-ESO-1 could be efficiently detected in peripheral blood. Specific T cells utilised a range of different T cell receptors, indicating a polyclonal response. Specific killing of a panel of NY-ESO-1 expressing tumour cell lines indicates recognition restricted to several HLA allelic variants, including a novel HLA-B49 epitope. Using a modified mRNA construct targeting the translated antigen to the secretory pathway, detection of NY-ESO-1-specific CD4+ T cells in patients could be enhanced, which allowed the in-depth characterisation of established T cell clones. Moreover, broad CD8+ and CD4+ T cell responses covering multiple epitopes were detected following mRNA stimulation of patients treated with a recombinant vaccinia/fowlpox NY-ESO-1 vaccine. This approach allows for a precise monitoring of responses to tumour antigens in a setting that addresses the breadth and magnitude of antigen-specific T cell responses, and that is not limited to a particular combination of known epitopes and HLA-restrictions.
authors.affiliation: Medical Oncology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland. ashley.knights@usz.ch
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Knights
authors.forename: Natko
authors.initials: N
authors.lastname: Nuber
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Thomson
authors.forename: Olga
authors.initials: O
authors.lastname: de la Rosa
authors.forename: Elke
authors.initials: E
authors.lastname: Jäger
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Tiercy
authors.forename: Maries
authors.initials: M
authors.lastname: van den Broek
authors.forename: Steve
authors.initials: S
authors.lastname: Pascolo
authors.forename: Alexander
authors.initials: A
authors.lastname: Knuth
authors.forename: Alfred
authors.initials: A
authors.lastname: Zippelius
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D019496:Cancer Vaccines; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism; D045744:Cell Line, Tumor; D000939:Epitopes / Q000737:chemistry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism; D008957:Models, Genetic; D009369:Neoplasms / Q000097:blood* / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D000939:Epitopes; D010455:Peptides; D012333:RNA, Messenger; D007371:Interferon-gamma