The roles of Ptpn22 Ser452 phosphorylation in tumor-infiltrating CD8+ T cells from mouse. The roles of Ptpn22 Ser452 phosphorylation in tumor-infiltrating CD8+ T cells from mouse

Protein Tyrosine Phosphatase Non-receptor type 22 (PTPN22) is encoded by a major autoimmunity gene and is a known inhibitor of T cell receptor (TCR) signaling for cancer immunotherapy. However, little is known about PTPN22 phosphorylation in tumor infiltrating T cells. Here we characterize a phosphorylation site at Ser452 situated in the interdomain of PTPN22, and its roles in altering T cell function and tumor growth. Tumor infiltrating CD8+ T cells from PepWT or PepS452A mice were collected and subjected to next-generation sequencing (NGS). The results revealed it differentially regulates the genes expression of metabolic process, cytokine prodcution and adaptive immunity etc. This study explores the function of a novel phosphorylation site of PTPN22 that is involved in complex regulation of CD8+ T cell activity, fuctions and tumor growth. Overall design: MC38 tumor cells were injected into PepWT or PepS425A mice and tumors were collected after 18days and digested by collagenase to get the single cell suspensions. CD8+ T cells were sorted out by cell sortor and used for bulk RNA sequencing,