Tumor cell programmed death ligand 1-mediated T cell suppression is overcome by coexpression of CD80

J Immunol. 2011 Jun 15;186(12):6822-9. doi: 10.4049/jimmunol.1003682. Epub 2011 May 9.


Programmed death ligand 1 (PDL1, or B7-H1) is expressed constitutively or is induced by IFN-γ on the cell surface of most human cancer cells and acts as a "molecular shield" by protecting tumor cells from T cell-mediated destruction. Using seven cell lines representing four histologically distinct solid tumors (lung adenocarcinoma, mammary carcinoma, cutaneous melanoma, and uveal melanoma), we demonstrate that transfection of human tumor cells with the gene encoding the costimulatory molecule CD80 prevents PDL1-mediated immune suppression by tumor cells and restores T cell activation. Mechanistically, CD80 mediates its effects through its extracellular domain, which blocks the cell surface expression of PDL1 but does not prevent intracellular expression of PDL1 protein. These studies demonstrate a new role for CD80 in facilitating antitumor immunity and suggest new therapeutic avenues for preventing tumor cell PDL1-induced immune suppression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / immunology*
  • B7-1 Antigen / administration & dosage
  • B7-1 Antigen / genetics
  • B7-1 Antigen / immunology*
  • B7-H1 Antigen
  • Cell Line, Tumor
  • Gene Expression / drug effects
  • Humans
  • Immunotherapy / methods
  • Lymphocyte Activation / immunology
  • T-Lymphocytes / immunology*
  • Transfection


  • Antigens, CD
  • B7-1 Antigen
  • B7-H1 Antigen
  • CD274 protein, human