Display Settings:

Format

Send to:

Choose Destination
    Nat Immunol. 2004 Feb;5(2):169-74. Epub 2004 Jan 11.

    Saposin C is required for lipid presentation by human CD1b.

    Source

    Max-Planck-Institute for Infection Biology, Department of Immunology, Schumannstrasse 21-22, D-10117 Berlin, Germany.

    Erratum in

    • Nat Immunol. 2004 Mar;5(3):344.

    Abstract

    Lipids from Mycobacterium tuberculosis are presented through CD1 proteins to T lymphocytes in humans, but the accessory molecules required for antigen loading and presentation remain unidentified. Here we show that fibroblasts deficient in sphingolipid activator proteins (SAPs) transfected with CD1b failed to activate lipid-specific T cells. However, the T cell response was restored when fibroblasts were reconstituted with SAP-C but not other SAPs. Lipid antigen and SAP-C colocalized in lysosomal compartments, and liposome assays showed that SAP-C efficiently extracts antigen from membranes. Coprecipitation demonstrated direct molecular interaction between SAP-C and CD1b. We propose a model in which SAP-C exposes lipid antigens from intralysosomal membranes for loading onto CD1b. Thus, SAP-C represents a missing link in antigen presentation of lipids through CD1b to human T cells.

    PMID:
    14716313
    [PubMed - indexed for MEDLINE]

      Supplemental Content

      Icon for Nature Publishing Group

      Save items

      loading

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk