Ablation of S1PR4 triggers CD8+ T cell expansion to reduce tumor growth and improve therapy

We studied the role of S1PR4 on tumor progression using the PyMT mammary carcinoma mouse model and the AOM/DSS model for colitis-associated cancer. To gain insights of the underlying mechanism how S1PR4 ablation resulted in enhanced intratumoral CD8+ T cell abundance, we performed whole transcriptome profiling of total WT and S1PR4 KO colons subjected to the AOM/DSS model (day 84) as well as FACS-sorted CD8+ T cells from WT and S1PR4 KO tumors of PyMT mice. Next-generation mRNA sequencing, in triplicates, on a NextSeq 500 (PyMT CD8+ T cells) or a HiSeq 2000 (AOM/DSS model) high-throughput sequencer was used. mRNA profiles of total colons of WT and S1PR4 KO mice at day 84 of the AOM/DSS model and of FACS-sorted CD8+ T cells from WT and S1PR4 KO PyMT tumors at the experimental endpoint (when one tumor reached a diameter of about 1.5 cm) were generated in triplicates.