Loading of the Antigen‐Presenting Protein CD1d with Synthetic Glycolipids

Wallner, Fredrik K.; Chen, Liying; Moliner, Annalena; Jondal, Mikael; Elofsson, Mikael

doi:10.1002/cbic.200300655

Cited by 8 publications

(6 citation statements)

References 39 publications

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“…However, only a fraction of NKT cells detected by agalactosylceramide (a-GalCer) could be stained by a CD1d tetramer loaded with mycobacterial PIM [6]. A recent study [7] was able to show the binding of synthetic a-GalNAc containing GSL to cell surface CD1d, but no functional studies were done to demonstrate the T cell relevance of this antigen. To date, aGalCer -originally isolated from marine sponges [8] -is the only available ligand for phenotypically and functionally characterizing NKT cells.…”

Section: Introductionmentioning

confidence: 99%

Cell wall glycosphingolipids ofSphingomonas paucimobilisare CD1d-specific ligands for NKT cells

et al. 2005

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The current consensus on characterization of NKT cells is based on their reactivity to the synthetic glycolipid, a-galactosylceramide (a-GalCer) in a CD1d-dependent manner. Because of the limited availability of a-GalCer, there is a constant search for CD1d-presented ligands that activate NKT cells. The a-anomericity of the carbohydrate is considered to be an important requisite for the CD1d-specific activation of NKT cells. The gram-negative, lipopolysaccharide-free bacterium Sphingomonas paucimobilis is known to contain glycosphingolipids (GSL) with a-anomeric sugars attached to the lipid chain. Here, we report that GSL extracted from this bacterium are able to stimulate NKT cells in a CD1d-specific manner. In addition, soluble CD1d-Ig dimers loaded with this lipid extract specifically bind to NKT cells (but not conventional T cells). Further studies on the S. paucimobilis GSL could potentially lead to other natural sources of CD1d-specific ligands useful for NKT cell analyses and aimed at identifying novel therapies for a variety of disease states. IntroductionLipid antigens, including phospholipids and glycosphingolipids (GSL), are presented by CD1d -a subset of the CD1 family of MHC class I-like molecules -to specialized immune effector cells called NKT cells [1]. Located on a different chromosome than the MHC, five different CD1 genes encode CD1 molecules -CD1a, CD1b, CD1c, CD1d and CD1e -in humans, whereas only two homologues of CD1d (CD1d1 and CD1d2) are present in mice [2]. On the basis of the crystal structure of mouse CD1d1 [3], it is predicted that the fatty-acyl chains are buried in the hydrophobic pocket of the molecule with the hydrophilic head-group of the lipid antigen available outside the molecule for its interaction with the NKT cell receptor. Even though the lipidbinding groove of CD1d is widely accommodative of many lipid groups, it is believed that only the sugar structures in a-anomeric orientation are able to stimulate NKT cells [4]. Because of the lack of physiological glycolipids with terminal a-anomeric sugars, it is hypothesized that both altered selfglycolipids during a pathological process and exogenous antigenic glycolipids could be potential ligands presented by CD1d [4]. The presence of GSL in the cell wall of some bacterial strains indicates the possibility of these bacterial GSL being presented by CD1d. Although human CD1a, b and c molecules are known to present mycobacterial antigens to human NKT cells, there is a lack of substantial evidence to show that CD1d has the ability to present these microbial lipids [5]. In a recent study, Fischer et al. [6] were able to show that mycobacterial phosphoinositolmannosides (PIM) could bind to soluble CD1d and activate human and mouse NKT cells. However, only a fraction of NKT cells detected by agalactosylceramide (a-GalCer) could be stained by a CD1d tetramer loaded with mycobacterial PIM [6]. A recent study [7] was able to show the binding of synthetic a-GalNAc containing GSL to cell surface CD1d, but no functional studies were done t...

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Section: Introductionmentioning

confidence: 99%

Cell wall glycosphingolipids ofSphingomonas paucimobilisare CD1d-specific ligands for NKT cells

et al. 2005

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“…To explore the mechanistic and kinetic details of ligand association with CD1d molecules, a more direct method of detecting α-GalCer:CD1d complexes would be of great value. The straightforward technique of using fluorescent, radio-or biotin-labeled α-GalCer molecules as probes for complex formation is hampered by the problem that these probes can associate with the cell surface independently of CD1d, probably through nonspecific interactions with membranes and hydrophobic protein domains (Wallner et al, 2004; data not shown).…”

Section: Introductionmentioning

confidence: 99%

Production and characterization of monoclonal antibodies against complexes of the NKT cell ligand α-galactosylceramide bound to mouse CD1d

Yu¹,

Im²,

Illarionov³

et al. 2007

Journal of Immunological Methods

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The alpha-galactosylceramide (alpha-GalCer) known as KRN7000 remains the best studied ligand of the lipid-binding MHC class I-like protein CD1d. The KRN7000:CD1d complex is highly recognized by invariant natural killer T (iNKT) cells, an evolutionarily conserved subset of T lymphocytes that express an unusual semi-invariant T cell antigen receptor, and mediate a variety of proinflammatory and immunoregulatory functions. To facilitate the study of glycolipid antigen presentation to iNKT cells by CD1d, we undertook the production of mouse monoclonal antibodies (mAbs) specific for complexes of KRN7000 bound to mouse CD1d (mCD1d) proteins. Three such monoclonal antibodies were isolated that bound only to mCD1d proteins that were loaded with KRN7000 or closely-related forms of alpha-GalCer. These mAbs showed no reactivity with mCD1d proteins that were not loaded with alpha-GalCer, nor did they bind to complexes formed by loading mCD1d with the self-glycolipid and putative iNKT cell ligand isoglobotrihexosylceramide. These complex-specific monoclonal antibodies allow the direct detection and monitoring of complexes formed by the binding of KRN7000 and other alpha-GalCer analogues to mCD1d. The availability of these mAbs should facilitate a wide range of studies on the biology and potential clinical applications of CD1d-restricted iNKT cells.

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“…One is to depend on high-throughput screening of a huge number of drug candidates produced by combinatorial chemistry. 49 However, both RCAI-5 and RCAI-6 were almost inactive. The other is to design candidate compounds by so-called "structure-based design" using the structural information obtained by X-ray crystallographic analysis of a lead compound and its receptor protein.…”

Section: Analogs Of Krn7000 Prepared In 2003-2006mentioning

confidence: 98%

Synthesis of Marine Bioregulators, Medicinals and Related Compounds

Mori

2010

Chemical Synthesis of Hormones, Pheromones and Other Bioregulators

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Loading of the Antigen‐Presenting Protein CD1d with Synthetic Glycolipids

Cited by 8 publications

References 39 publications

Cell wall glycosphingolipids ofSphingomonas paucimobilisare CD1d-specific ligands for NKT cells

Cell wall glycosphingolipids ofSphingomonas paucimobilisare CD1d-specific ligands for NKT cells

Production and characterization of monoclonal antibodies against complexes of the NKT cell ligand α-galactosylceramide bound to mouse CD1d

Synthesis of Marine Bioregulators, Medicinals and Related Compounds

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