Immunosuppressive B cells expressing PD-1/PD-L1 in solid tumors: A mini review.

Expression of Programmed Cell Death-1 (PD-1/CD279) on T cells and the ligand of PD-1, PD-L1 (CD274/B7-H1) on tumor cells or other immune cells, such as myeloid-derived suppressor cells, are important mechanisms to induce malignant immunosuppression. PD-1/PD-L1 expression on B cell subsets, as well as their signaling and inhibitory functions in solid tumors will be discussed in this review with the focus on how B cells expressing PD-1/PD-L1 play immunosuppressive roles in tumor progression, aiming to figure out the potential for development of diagnostic tools and new therapies involving this unique group of cells.