Fig. 5.
In vitro vaccination with LRPAP1 V-SLP results in expansion of tumor-reactive TEIPP-specific T cells. a Schematic overview of the in vitro vaccination protocol using V-variant synthetic long peptides for priming of CD8 T cells from PBMC of healthy donors. b Different N-terminal extended length variants (18-mer to 27-mer) of the V-SLP were co-cultured with moDCs from three different donors. The capacity to cross-present the epitope and to induce expansion of peptide-specific T cells was analyzed by measuring the frequencies of LRPAP121–30-specific CD8 T cells by peptide/HLA-A2 multimer staining. As control, moDCs were incubated with PBMC without long peptide. Representative data out of three experiments is shown. c Two LRPAP1-specific T cell clones (2H11 and 1A10) were generated from SLP-induced T cell bulks by single-cell sorting. LRPAP1 specificity was measured by flow cytometry. Clone 1A8 was isolated from a previous study [15], and used as a reference clone. b LRPAP1-specific T cell clones were tested for reactivity against TAP-KO cancer cells and their WT counterparts. Clone 1A8 was used as a reference T cell clone. Means and SD are shown from one out of two experiments with similar outcome