Predominant expression of B7-H1 and its immunoregulatory roles in oral squamous cell carcinoma

Oral Oncol. 2006 Mar;42(3):268-74. doi: 10.1016/j.oraloncology.2005.07.013. Epub 2005 Nov 3.


We examined cell surface expression of five B7 costimulatory molecules (B7-H1, B7-DC, B7h, CD80 and CD86) in human oral squamous cell carcinoma (SCC) lines. Most human SCC cell lines expressed various levels of B7-H1 and B7-DC. Their expression was further upregulated by interferon (IFN)-gamma stimulation. Immunohistochemical staining revealed substantial and predominant expression of B7-H1 on human primary oral SCC. A murine SCC line, NR-S1, neither expressed B7-H1 nor B7-DC, but induced B7-H1 by IFN-gamma stimulation in culture and the inoculation in vivo. Although NR-S1 tumors grew progressively in immunocompetent syngeneic mice, the administration of blocking anti-B7-Hl or anti-PD-1 mAb significantly inhibited the tumor growth, suggesting the negative regulation of host immune responses by the PD-1:B7-H1 pathway. Our results demonstrate that B7-H1 is predominantly induced on oral SCC within the B7 family molecules. A successful inhibition of tumor growth by blockade of the PD-1:B7-H1 pathway may implicate a new approach for immunotherapy of oral SCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Neoplasm / immunology*
  • B7-1 Antigen / metabolism*
  • Carcinoma, Squamous Cell / immunology*
  • Cell Line, Tumor
  • Female
  • Flow Cytometry / methods
  • Humans
  • Interferon-gamma / immunology
  • Mice
  • Mice, Inbred C3H
  • Mouth Neoplasms / immunology*
  • Programmed Cell Death 1 Ligand 2 Protein


  • Antigens, Neoplasm
  • B7-1 Antigen
  • PDCD1LG2 protein, human
  • Pdcd1lg2 protein, mouse
  • Programmed Cell Death 1 Ligand 2 Protein
  • Interferon-gamma