Background The identification of neo-antigens presented by tumor cells is an essential tool for cancer prevention, diagnosis, and therapy. Current approaches frequently involve mass spectrometric analysis, but these workflows do not concomitantly identify the cognate T-cell receptor. Likewise, TCR functional screens are often limited to a subset of predicted neo-epitopes.

Materials and Methods Here, we present a new method for the generation of an un-biased antigen-presenting library. Due to the genomic instability of tumors, patient-specific libraries will be cloned using random primers, ensuring the cloning of tumor-specific transcribed regions. This approach will not only address class I presentation of intracellular tumor antigens, but is also designed to simultaneously screen for cross-presentation on class II MHC complexes by professional antigen-presenting cells, an increasingly important component of anti-tumor immune responses. To guarantee presentation of genetically encoded antigens on class II MHC complexes, a signal motif for chaperone-mediated autophagy (CMA) is introduced in front of the cDNA sequence. Furthermore, antigens will be processed by the intracellular machinery, avoiding potential restrictions on spliced peptides.

Conclusions Once established, these libraries can be exploited in high-throughput screens to functionally identify neo-antigens together with their corresponding T-cell receptor.

Disclosure Information V. Pinamonti: Other; Significant; Janssen. N. Felix: Other; Significant; Janssen. J.M. Lindner: Other; Significant; Janssen.