PD-L1-deficient mice show that PD-L1 on T cells, antigen-presenting cells, and host tissues negatively regulates T cells

Both positive and negative regulatory roles have been suggested for the B7 family member PD-L1(B7-H1). PD-L1 is expressed on antigen-presenting cells (APCs), activated T cells, and a variety of tissues, but the functional significance of PD-L1 on each cell type is not yet clear. To dissect the functions of PD-L1 in vivo , we generated PD-L1-deficient (PD-L1 –/– ) mice. CD4 + and CD8 + T cell responses were markedly enhanced in PD-L1 –/– mice compared with wild-type mice in vitro and in vivo . PD-L1 –/– dendritic cells stimulated greater wild-type CD4 + T cell responses than wild-type dendritic cells, and PD-L1 –/– CD4 + T cells produced more cytokines than wild-type CD4 + T cells in vitro , demonstrating an…

• NM
  National Multiple Sclerosis Society
• LA
  Leukemia and Lymphoma Society
• WT
  Wellcome Trust
• MS
  Multiple Sclerosis Society
• NI
  National Institutes of Health