Dataset related to article "Identification of a class of non-conventional ER-stress response-derived immunogenic peptides (ERStreP)"

This record contains raw data and scripts (R software) applied to get Figure 5 and Figure S8 related to article “Identification of a class of non-conventional ER-stress response-derived immunogenic peptides (ERStreP)” Immune checkpoint blockade (ICB) has changed the prognosis of previously untreatable tumors. However, a fraction of patients is refractory to ICB therapy. Ongoing efforts to overcome resistance have focused on vaccination strategies using neoepitopes, although these cannot be applied on a large scale due to the "private" nature of cancer mutations. Here we show that infection of tumor cells with <em>Salmonella</em> induces the opening of membrane hemichannels and the release of proteasome-generated peptides in the extracellular milieu via the exacerbation of endoplasmic reticulum (ER)-stress and the unfolded protein response. Peptides released by cancer cells induced a strong antitumor response <em>in vivo</em>, both in mice bearing B16F10 melanomas and in dogs suffering of osteosarcoma and high-grade sarcoma. Mass spectrometry analysis on the supernatant of human melanoma cells revealed 12 released peptides capable of priming healthy donor CD8⁺ T cells that recognize and kill human melanoma cells <em>in vitro</em> and when xenotransplanted <em>in vivo</em>, but not healthy melanocytes. Hence, we identified a novel class of tumor antigens that are generated in ER-stressed cells, such as tumor cells, and that do not induce central or peripheral tolerance, nor are presented by healthy cells.