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Saposin C is required for lipid presentation by human CD1b

A Corrigendum to this article was published on 01 March 2004

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.

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Figure 1: Generation of APCs from human fibroblasts.
Figure 2: Antigen-specific activation of lipid-reactive T cell clones.
Figure 3: The effect of SAP-C in antigen presentation is not dependent on β-glucosidase activity.
Figure 4: Subcellular localization of LAM, SAP-C and CD1b.
Figure 5: SAP-C extracts LAM from membranes.
Figure 6: Molecular interactions between SAP-C and CD1b.

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References

  1. Porcelli, S. et al. Recognition of cluster of differentiation 1 antigens by human CD4-CD8-cytolytic T lymphocytes. Nature 341, 447–450 (1989).

    Article  CAS  Google Scholar 

  2. Sieling, P.A. et al. CD1-restricted T cell recognition of microbial lipoglycan antigens. Science 269, 227–230 (1995).

    Article  CAS  Google Scholar 

  3. Porcelli, S.A. & Modlin, R.L. The CD1 system: antigen-presenting molecules for T cell recognition of lipids and glycolipids. Annu. Rev. Immunol. 17, 297–329 (1999).

    Article  CAS  Google Scholar 

  4. Moody, D.B. & Porcelli, S.A. Intracellular pathways of CD1 antigen presentation. Nat. Rev. Immunol. 3, 11–22 (2003).

    Article  CAS  Google Scholar 

  5. Joyce, S. & Van Kaer, L. CD1-restricted antigen presentation: an oily matter. Curr. Opin. Immunol. 15, 95–104 (2003).

    Article  CAS  Google Scholar 

  6. Calabi, F., Jarvis, J.M., Martin, L. & Milstein, C. Two classes of CD1 genes. Eur. J. Immunol. 19, 285–292 (1989).

    Article  CAS  Google Scholar 

  7. Gadola, S.D. et al. Structure of human CD1b with bound ligands at 2.3 Å, a maze for alkyl chains. Nat. Immunol. 3, 721–726 (2002).

    Article  CAS  Google Scholar 

  8. Moody, D.B. et al. Structural requirements for glycolipid antigen recognition by CD1b-restricted T cells. Science 278, 283–286 (1997).

    Article  CAS  Google Scholar 

  9. Shamshiev, A. et al. Presentation of the same glycolipid by different CD1 molecules. J. Exp. Med. 195, 1013–1021 (2002).

    Article  CAS  Google Scholar 

  10. Brennan, P.J. & Besra, G.S. Structure, function and biogenesis of the mycobacterial cell wall. Biochem. Soc. Trans. 25, 188–194 (1997).

    Article  CAS  Google Scholar 

  11. Moody, D.B. et al. Lipid length controls antigen entry into endosomal and nonendosomal pathways for CD1b presentation. Nat. Immunol. 3, 435–442 (2002).

    Article  CAS  Google Scholar 

  12. Jackman, R.M. et al. The tyrosine-containing cytoplasmic tail of CD1b is essential for its efficient presentation of bacterial lipid antigens. Immunity 8, 341–351 (1998).

    Article  CAS  Google Scholar 

  13. Briken, V., Jackman, R.M., Dasgupta, S., Hoening, S. & Porcelli, S.A. Intracellular trafficking pathway of newly synthesized CD1b molecules. EMBO J. 21, 825–834 (2002).

    Article  CAS  Google Scholar 

  14. Sugita, M. et al. Failure of trafficking and antigen presentation by CD1 in AP-3-deficient cells. Immunity 16, 697–706 (2002).

    Article  CAS  Google Scholar 

  15. Schaible, U.E., Hagens, K., Fischer, K., Collins, H.L. & Kaufmann, S.H. Intersection of group I CD1 molecules and mycobacteria in different intracellular compartments of dendritic cells. J. Immunol. 164, 4843–4852 (2000).

    Article  CAS  Google Scholar 

  16. Prigozy, T.I. et al. The mannose receptor delivers lipoglycan antigens to endosomes for presentation to T cells by CD1b molecules. Immunity 6, 187–197 (1997).

    Article  CAS  Google Scholar 

  17. O'Brien, J.S. et al. Coding of two sphingolipid activator proteins (SAP-1 and SAP-2) by same genetic locus. Science 241, 1098–1101 (1988).

    Article  CAS  Google Scholar 

  18. Schuette, C.G., Pierstorff, B., Huettler, S. & Sandhoff, K. Sphingolipid activator proteins: proteins with complex functions in lipid degradation and skin biogenesis. Glycobiology 11, 81R–90R (2001).

    Article  CAS  Google Scholar 

  19. Vaccaro, A.M., Salvioli, R., Tatti, M. & Ciaffoni, F. Saposins and their interaction with lipids. Neurochem. Res. 24, 307–314 (1999).

    Article  CAS  Google Scholar 

  20. Schnabel, D. et al. Simultaneous deficiency of sphingolipid activator proteins 1 and 2 is caused by a mutation in the initiation codon of their common gene. J. Biol. Chem. 267, 3312–3315 (1992).

    CAS  PubMed  Google Scholar 

  21. Vielhaber, G., Hurwitz, R. & Sandhoff, K. Biosynthesis, processing, and targeting of sphingolipid activator protein (SAP) precursor in cultured human fibroblasts. Mannose 6-phosphate receptor-independent endocytosis of SAP precursor. J. Biol. Chem. 271, 32438–32446 (1996).

    Article  CAS  Google Scholar 

  22. Vaccaro, A.M. et al. Effect of saposins A and C on the enzymatic hydrolysis of liposomal glucosylceramide. J. Biol. Chem. 272, 16862–16867 (1997).

    Article  CAS  Google Scholar 

  23. Morimoto, S. et al. Interaction of saposins, acidic lipids, and glucosylceramidase. J. Biol. Chem. 265, 1933–1937 (1990).

    CAS  PubMed  Google Scholar 

  24. Vaccaro, A.M. et al. pH-dependent conformational properties of saposins and their interactions with phospholipid membranes. J. Biol. Chem. 270, 30576–30580 (1995).

    Article  CAS  Google Scholar 

  25. Wilkening, G., Linke, T. & Sandhoff, K. Lysosomal degradation on vesicular membrane surfaces. Enhanced glucosylceramide degradation by lysosomal anionic lipids and activators. J. Biol. Chem. 273, 30271–30278 (1998).

    Article  CAS  Google Scholar 

  26. Harzer, K. et al. Sphingolipid activator protein deficiency in a 16-week-old atypical Gaucher disease patient and his fetal sibling: biochemical signs of combined sphingolipidoses. Eur. J. Pediatr. 149, 31–39 (1989).

    Article  CAS  Google Scholar 

  27. Sugita, M. et al. Cytoplasmic tail-dependent localization of CD1b antigen-presenting molecules to MIICs. Science 273, 349–352 (1996).

    Article  CAS  Google Scholar 

  28. Moody, D.B. et al. CD1c-mediated T-cell recognition of isoprenoid glycolipids in Mycobacterium tuberculosis infection. Nature 404, 884–888 (2000).

    Article  CAS  Google Scholar 

  29. Ochoa, M.T. et al. T-cell release of granulysin contributes to host defense in leprosy. Nat. Med. 7, 174–179 (2001).

    Article  CAS  Google Scholar 

  30. Kaufmann, S.H. Is the development of a new tuberculosis vaccine possible? Nat. Med. 6, 955–960 (2000).

    Article  CAS  Google Scholar 

  31. Ham, D. Structural requirements for lysosomal targeting of the prosaposin precursor protein. Cell Biol. Int. 27, 675–687 (2003).

    Article  CAS  Google Scholar 

  32. Sieling, P.A. et al. Evidence for human CD4+ T cells in the CD1-restricted repertoire: derivation of mycobacteria-reactive T cells from leprosy lesions. J. Immunol. 164, 4790–4796 (2000).

    Article  CAS  Google Scholar 

  33. Moody, D.B. et al. CD1b-mediated T cell recognition of a glycolipid antigen generated from mycobacterial lipid and host carbohydrate during infection. J. Exp. Med. 192, 965–976 (2000).

    Article  CAS  Google Scholar 

  34. Schaible, U.E. & Kaufmann, S.H. Studying trafficking of intracellular pathogens in antigen-presenting cells. Methods Microbiol. 31, 343–360 (2002).

    Article  CAS  Google Scholar 

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Acknowledgements

We thank J.T. Belisle sharing reagents and J. Enders for technical assistance. Supported by the Deutsche Forschungsgemeinschaft (SFB 421, U.E.S. and S.H.E.K.; SPP 1131, U.E.S.).

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Correspondence to Stefan H E Kaufmann.

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Winau, F., Schwierzeck, V., Hurwitz, R. et al. Saposin C is required for lipid presentation by human CD1b. Nat Immunol 5, 169–174 (2004). https://doi.org/10.1038/ni1035

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