ATAC-seq of naive and three effector OT-I cell subsets from mice infected with Listeria monocytogenes

Purpose: ATAC-seq analysis of naive and three effector OT-I cell subsets (from a Klrg1-Cre fate reporter mouse model) isolated from the spleen of C57BL/6 mice 0 and 8 days post infection with OVA-expressing Listeria monocytogenes. The hypothesis tested in the present study was that chromatin remodeling in KLRG1+ effector CD8 T lymphocytes promotes the differentiation into KLRG1- memory CD8 T lymphocytes that provide long-lasting immunity against infectious diseases and malignancies. Methods: DNA was obtained from 50,000 FACS-purified OT-I cell subsets isolated from spleen 0 and 8 days post infection with ovalbumin-expressing Listeria monocytogenes (LM-OVA) (experiment 3). Results: Using ATAC-seq technology, we analyzed the chromatin accessibility landscape of naive and three effector OT-I cells (KLRG1+ Reporter+, KLRG1- Reporter+ (exKLRG1) and KLRG1- Reporter-). Conclusions: Our study represents the first fate mapping analysis of KLRG1+ effector OT-I cells, demonstrates that KLRG1+ effector OT-I cells differentiate into all memory T cell lineages thereby promoting protective immunity. RNA-seq identified CX3CR1 as a marker of circulating exKLRG1 early memory OT-I cells, and ATAC-seq analysis revealed that chromatin remodeling enabled exKLRG1 memory cells to exhibit both a high cytotoxic and proliferative capacity. Genomic DNA was obtained from FACS-purified OT-I cell subsets isolated from spleen 0 or 8 days post infection with ovalbumin-expressing Listeria monocytogenes (LM-OVA).