Expression of the co-stimulatory molecule B7 on melanoma cells

✍ Scribed by Peter Hersey; Zhaoyi Si; Melanie J. Smith; Wayne D. Thomas

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: French
• Weight: 679 KB
• Volume: 58
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910580413

✦ Synopsis

The induction of T-cell responses against tumor cells is believed to depend on both recognition of antigen and receipt of co-stimulator). signals from interaction of ligands such as B7 with its receptors CD28 or CTLA-4 on T cells. In the present study the expression of 87 on cultured human melanoma cells was studied at the mRNA level by reverse PCR analysis and surface expression by flow cytometric analysis with monoclonal antibodies (MAbs). PCR analysis revealed mRNA for B7 in 3 of 6 (50%) cultured primary melanoma and 8 of I 9 (42%) cultures of metastatic melanoma. Analysis of B7 expression by flow cytometr). using the BB I MAb revealed low levels of expression in 3 of I0 melanoma that had mRNA for 87. In 2 of the latter (but not 4 other PCR+ lines) expression could be increased by culture in GM-CSF, IL-2, IFN-y and IFN-a2. Our results indicate that although mRNA for 87 is present in 40-50% of melanoma cell lines, expression at the protein level is at low or undetectable levels in the majority of the cell lines. Expression of 87 protein was also not detected in studies on tissue sections from I I primary and 9 metastatic melanomas. li) 1994 IV/l.),-L15J, ItlC