B7-H Abnormalities in Melanoma and Clinical Relevance
Melanoma have been shown to escape immune surveillance by different mechanisms such as loss of HLA class I antigens, upregulation of nonclassical HLA-G antigen and Fas, increased secretion of immune suppressive cytokines and metabolites as well as altered expression of co-stimulatory and coinhibitory signals. Recently, an important role of B7-H1 and B7-H4 in the immune escape of melanoma has been described. High mRNA and/or protein expression levels of these coinhibitory molecules were detected in both melanoma cell lines and melanoma lesions when compared to melanocytes. However, their clinical relevance is currently controversially discussed regarding a correlation of B7-H family members with tumor grading and staging as well as survival of patients in melanoma.
Key wordsMHC antigens Coinhibitory molecules Immune escape Melanoma
Antigen presenting cell
B- and T-lymphocyte attenuator
Cytotoxic T lymphocyte
Cytotoxic T-lymphocyte antigen 4
Human leukocyte antigen
Mean specific fluorescence intensity
Phosphate buffered saline
Programmed cell death
T cell receptor
This work was supported from grants of the Mildred Scheel Cancer Foundation, the Wilhelm Sander Foundation and the intramural Wilhelm Roux Program.