Phage display-derived recombinant antibodies with TCR-like specificity against α-galactosylceramide and its analogues in complex with human CD1d molecules

2008 
The glycolipid α-galactosylceramide (α-GalCer) is a potent activator of invariant natural killer T (iNKT) cells and has been shown to be an effective agent against cancer, infections and autoimmune diseases. The effectiveness of α-GalCer and its alkyl chain analogues depends on efficient loading and presentation by the antigen-presenting molecule CD1d. To monitor the ability of CD1d to present the glycolipids, we have used a phage display strategy to generate recombinant antibodies with T cell receptor-like (TCRL) specificity against the human CD1d (hCD1d)-α-GalCer complex. These Fab fragments were able to detect specifically hCD1d-α-GalCer complexes in cell-free systems such as surface plasmon resonance and ELISA, as well as on the surface of hCD1d+ antigen-presenting cells (APC) by flow cytometry and immunofluorescence microscopy, the latter of which could also detect intracellular complexes. We show that our TCRL antibodies can stain dendritic cells from CD11c-hCD1d-transgenic mice administered in vivo with α-GalCer and its analogues. Furthermore, the antibody was also able to detect the presentation by hCD1d molecules of analogues of α-GalCer with the same polar head structure. Using this reagent, we were able to confirm directly that the α-GalCer analogue C20:2 preferentially loads onto cell surface CD1d rapidly without the need for internalization, while the loading of α-GalCer is improved with longer incubation times on professional APC. This reagent will be essential for assessing the loading and presenting capabilities of hCD1d of α-GalCer and its analogues.
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    43
    References
    15
    Citations
    NaN
    KQI
    []