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Differential contribution of TAP and tapasin to HLA class I antigen expression.
- Source :
-
Immunology . May2008, Vol. 124 Issue 1, p112-120. 9p. 5 Graphs. - Publication Year :
- 2008
-
Abstract
- Expression of class I human leucocyte antigens (HLA) on the surface of malignant cells is critical for their recognition and destruction by cytotoxic T lymphocytes. Surface expression requires assembly and folding of HLA class I molecules in the endoplasmic reticulum with the assistance of proteins such as Transporter associated with Antigen Processing (TAP) and tapasin. Interferon-γ induces both TAP and tapasin so dissection of which protein contributes more to HLA class I expression has not been possible previously. In this study, we take advantage of a human melanoma cell line in which TAP can be induced, but tapasin cannot. Interferon-γ increases TAP protein levels dramatically but HLA class I expression at the cell surface does not increase substantially, indicating that a large increase in peptide supply is not sufficient to increase HLA class I expression. On the other hand, transfection of either allelic form of tapasin (R240 or T240) enhances HLA-B*5001 and HLA-B*5701 antigen expression considerably with only a modest increase in TAP. Together, these data indicate that in the presence of minimal TAP activity, tapasin can promote substantial HLA class I expression at the cell surface. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00192805
- Volume :
- 124
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Immunology
- Publication Type :
- Academic Journal
- Accession number :
- 31641843
- Full Text :
- https://doi.org/10.1111/j.1365-2567.2007.02746.x