1. Modified tumour antigen-encoding mRNA facilitates the analysis of naturally occurring and vaccine-induced CD4 and CD8 T cells in cancer patients
- Author
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Knights, A J, Nuber, N, Thomson, C W, de la Rosa, O, Jäger, E, Tiercy, J M, van den Broek, Maries; https://orcid.org/0000-0002-9489-3692, Pascolo, S, Knuth, A, Zippelius, A, Knights, A J, Nuber, N, Thomson, C W, de la Rosa, O, Jäger, E, Tiercy, J M, van den Broek, Maries; https://orcid.org/0000-0002-9489-3692, Pascolo, S, Knuth, A, and Zippelius, A
- 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.
- Published
- 2009