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A Technique to Simultaneously Visualize Virus-Specific CD8+ T Cells and Virus-Infected Cells In situ
Published on: August 13, 2009
Presentation of viral antigen by MHC class I molecules is dependent on a putative peptide transporter heterodimer
T Spies1, V Cerundolo, M Colonna
1Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115.
Abstract:
Major histocompatibility complex (MHC) class I molecules present peptides derived from the endogenous protein pool to cytotoxic T lymphocytes, which can thus recognize intracellular antigen. This pathway may depend on a transporter (PSF1) to mediate entry of the cytosolic peptides into a pre-Golgi compartment where they bind to class I heavy chains and promote their stable assembly with beta 2-microglobulin. There is, however, only indirect support for this function of PSF1. Here we show that PSF1 is necessary for the efficient assembly of class I molecules and enables them to present a peptide epitope derived from endogenously synthesized viral antigen. Immunochemical and genetic data demonstrate that the PSF1 polypeptide is associated with a complementary transporter chain, which is polymorphic and is encoded by the PSF2 gene, which is closely linked to PSF1.
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