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Max Planck Institute for Molecular Biomedicine |
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Max Planck Institute for Molecular Biomedicine |
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Department of Vascular Cell Biology
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PD Dr. Martin K. Wild | 
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Immune responses are critically dependent on the ability of leukocytes to migrate to sites of infection (inflamed tissues) and sites of antigen presentation (secondary lymphoid organs). Leukocytes are transported to these sites by the circulation and extravasate from the blood into the tissues upon interactions with endothelial cells which line the blood vessels.
Figure 1 shows that the extravasation of leukocytes is initiated by tethering and rolling of the cells on activated endothelium (in inflamed tissues) and so called high endothelial venules (in secondary lymphoid organs). These transient interactions are mediated by the selectins, adhesion molecules which recognize a limited range of specifically modified glycoproteins and -lipids. Three selectins are known: E-selectin (expressed by endothelial cells), P-selectin (expressed by platelets and endothelial cells) and L-selectin (found on leukocytes). Selectin-mediated leukocyte rolling is required for the consecutive activation of the leukocytes by endothelial cell-bound chemokines. As a consequence of activation leukocyte integrins, another class of adhesion molecules, mediate firm cellular adhesion to the endothelial wall. Finally, leukocytes transmigrate through the endothelium into the underlying tissue.
Figure 1: The "adhesion cascade": Interactions between leukocytes and endothelium. Leukocyte - endothelial cell contacts are initiated by selectin-dependent tethering and rolling, followed by chemokine-mediated activation, integrin-dependent firm adhesion and spreading and, finally, extravasation into the underlying tissue.
Our research focuses in particular on the first step of the "adhesion cascade", the selectin-dependent tethering and rolling of leukocytes. Selectins bind to carbohydrate structures which contain the monosaccharides fucose and sialic acid (neuraminic acid). The prototype structure is the tetrasaccharide Sialyl-Lewis X (sLex) which is shown in Figure 2.
Figure 2:Structure of the Sialyl-Lewis X blood group antigen. Sialyl-Lewis X is composed of four monosaccharides: neuraminic acid (NeuAc), galactose (Gal), N-acetyl-glucosamine (GlcNAc), and fucose (Fuc). The glycosidic linkages are shown. "R" indicates an oligo- or polysaccharide residue which is bound to a protein or a lipid.
Leukocyte Adhesion Deficiency II (LAD II) is a human congenital disease in which the biosynthesis of sLex and other fucosylated structures is blocked. Consequently, selectin-mediated adhesion is inhibited (Figure 3). The fucoslyation defect in LAD II leads to immunodeficiency, neutrophilia, as well as to psychomotor and growth retardation (Wild et al., 2002). LAD II is also termed "Congenital Disorder of Glycosylation-IIc (CDG-IIc)">.
Figure 3: Defective leukocyte-endothelial cell interacions in LAD II. LAD II patients exhibit a systemic hypofucosylation which includes selectin ligands. This inhibits selectin-mediated leukocyte-endothelial cell interactions. The consequence is decreased leukocyte extravasation causing immunodeficiency.
Several years ago the third LAD II patient worldwide was identified at the University Hospital in Münster. Prof. Thorsten Marquardt and Dr. Kerstin Lühn were able to show that oral supplementation with L-fucose could correct the neutrophilia and the immune defect in this patient.
Using complementation experiments we were later able to identify the genetic defect of LAD II. We found that mutations in the gene for the GDP-fucose transporter of the Golgi compartment are responsible for the fucosylation defect (Lühn et al., 2001) Simultaneously, the group of Christian Körner and Kurt von Figura in Göttingen showed the same genetic defect.
The GDP-fucose transporter translocates the nucleotide sugar GDP-fucose from the cytosol into the Golgi where this activated monosaccharide is used as a donor in fucosylation reactions. All LAD II patients that have been analysed so far show inactivating mutations in the GDP-fucose transporter.
The GDP-fucose transporter is located in the Golgi membrane and is composed of ten trans-membrane domains (Figure 4).
Figure 4: The GDP-fucose transporter. Topology and orientation of the human GDP-fucose transporter in the Golgi membrane.
Analysing all known defective GDP-fucose transporters we could recently show that LAD II patients can be devided into two groups (Helmus et al., 2006) (Figure 5):
Figure 5:Groups of LAD II patients. Two groups of LAD II patients can be distinguished on the basis of the molecular defect of the GDP-fucose transporter. ER, endoplasmic reticulum.
Leukocyte Adhesion deficiency II will remain in the direct focus of our research.
Dendritic cells (DC) play a central role in the initiation of specific immune responses due to their function as antigen presenting cells. In order to be able to take up antigen, immature / precursor DC have to leave the circulation and enter tissues. Using a contact hypersensitivity model in the mouse we found that the emigration of immature DC is only partially dependent on E- and P-selectin. We therefore postulated that other adhesion molecules contribute to the initiation of DC - endothelial cell interactions. Currently we are studying whether the fucose/mannose-specific lectin DC-SIGN and its ligand ICAM-2 are able to mediate DC interactions with endothelium in the mouse (e.g. Wethmar et al., 2006).
Further topics which we are actively working on:
* shared first authorship
Yakubenia, S., D. Frommhold, D. Schölch, C. C. Hellbusch, C. Körner, B. Petri, C. Jones, U. Ipe, M. G. Bixel, R. Krempien, M. Sperandio, and M. K. Wild. 2008. Leukocyte trafficking in a mouse model for Leukocyte Adhesion Deficiency II / Congenital Disorder of Glycosylation IIc. Blood, in press.
Vestweber, D., and M. K. Wild. 2008. A new player in lymphocyte homing. Nature Immunol. 9:347.
Urzainqui, A., G. Martínez Del Hoyo, A. Lamana, H. de la Fuente, O. Barreiro, I. M.Olazabal, P. Martin, M. K. Wild, D. Vestweber, R. González-Amaro, and F. Sánchez-Madrid. 2007. Functional role of P-selectin glycoprotein ligand 1/P-selectin interaction in the generation of tolerogenic dendritic cells. J. Immunol. 179:7457.
Döring, A., M. Wild, D. Vestweber, U. Deutsch, and B. Engelhardt. 2007. E- and P-selectin are not required for the development of experimental autoimmune encephalomyelitis in C57BL/6 and SJL Mice. J. Immunol., 179:8470.
Hidalgo, A., A. J. Pereid, M. K. Wild, D. Vestweber, and P. S. Frenette. 2007. Complete identification of E-selectin ligand activity on neutrophils reveals a dynamic interplay and distinct functions of PSGL-1, ESL-1 and CD44. Immunity, 26:477.
Filser C., D. Kowalczyk, C. Jones, M. K. Wild, U. Ipe, D. Vestweber, and H. Kunz. 2007. Synthetic glycopeptides from the E-selectin ligand-1 with varied Sialyl Lewisx structure as cell-adhesion inhibitors of E-selectin. Angewandte Chemie International Edition 46:2108.
Hellbusch CC, M. Sperandio, D. Frommhold, S. Yakubenia, M. K. Wild, D. Popovici, D. Vestweber, H. J. Grone, K. von Figura, T. Lübke, and C. Körner. 2007. Golgi GDP-fucose transporter-deficient mice mimic congenital disorder of glycosylation IIc/Leukocyte adhesion deficiency II. J Biol Chem. 282:10762.
Varga, G., S. Balkow, M. K. Wild, A. Stadtbaeumer, M. Krummen, T. Rothoeft, T. Higuchi, S. Beissert, K. Wethmar, K. Scharffetter-Kochanek, D. Vestweber, and S. Grabbe. 2007. Active Mac-1 (CD11b/CD18) on DC is inhibitory for full T cell activation. Blood 109:661.
Wethmar, K.*, Y. Helmus*, K. Lühn, C. Jones, A. Laskowska, G. Varga, S. Grabbe, R. Lyck, B. Engelhardt, M. G. Bixel, S. Butz, K. Loser, S. Beissert, U. Ipe, D. Vestweber, and M. K. Wild. 2006. Migration of immature dendritic cells across resting endothelium is mediated by ICAM-2 but independent of b2-integrins and murine DC-SIGN homologs. Eur. J. Immunol. 36:2781.
Yakubenia, S., and M. K. Wild. 2006. Leukocyte Adhesion Deficiency II: Advances and open questions. FEBS J. 273:4390.
Helmus, Y.*, J. Denecke*, S. Yakubenia, P. Robinson, K. Lühn, D. L. Watson, P. J. McGrogan, D. Vestweber, T. Marquardt, and M. K. Wild. 2006. Leukocyte adhesion deficiency II patients with a dual defect of the GDP-fucose transporter. Blood 107:3959.
Engelhardt, B., B. Kempe, S. Merfeld-Clauss, M. Laschinger, B. Furie, M. K. Wild, and D. Vestweber. 2005. P-Selectin Glycoprotein Ligand 1 Is Not Required for the Development of Experimental Autoimmune Encephalomyelitis in SJL and C57BL/6 Mice. J. Immunol. 175:1267.
Ashikov, A., F. Routier, J. Fuhlrott, Y. Helmus, M. Wild, R. Gerardy-Schahn, and H. Bakker. 2005. The human solute carrier gene SLC35B4 encodes a bifunctional nucleotide sugar transporter with specificity for UDP-xylose and UDP-N-acetylglucosamine. J. Biol. Chem. 280:27230.
Vestweber, D., K. Lühn, T. Marquardt, and M. Wild. 2004. The role of fucosylation in leukocyte adhesion deficiency II. Ernst Schering Research Foundation Workshop:53.
Lühn, K.*, A. Laskowska*, J. Pielage, C. Klämbt, U. Ipe, D. Vestweber, and M. K. Wild. 2004. Identification and molecular cloning of a functional GDP-fucose transporter in Drosophila melanogaster. Exp. Cell Res. 301:242.
Schwarz, A., A. Maeda, M. K. Wild, K. Kernebeck, N. Gross, Y. Aragane, S. Beissert, D. Vestweber, and T. Schwarz. 2004. Ultraviolet radiation-induced regulatory T cells not only inhibit the induction but can suppress the effector phase of contact hypersensitivity. Journal of Immunology 172:1036.
Wild, M. K., K. Lühn, T. Marquardt, and D. Vestweber. 2002. Leukocyte adhesion deficiency II: therapy and genetic defect. Cells Tissues Organs172:161.
Huang, M. C., A. Laskowska, D. Vestweber, and M. K. Wild. 2002. The alpha (1,3)-fucosyltransferase Fuc-TIV, but not Fuc-TVII, generates sialyl Lewis X-like epitopes preferentially on glycolipids. Journal of Biological Chemistry 277:47786.
Pendl, G. G., C. Robert, M. Steinert, R. Thanos, R. Eytner, E. Borges, M. K. Wild, J. B. Lowe, R. C. Fuhlbrigge, T. S. Kupper, D. Vestweber, and S. Grabbe. 2002. Immature mouse dendritic cells enter inflamed tissue, a process that requires E- and P-selectin, but not P-selectin glycoprotein ligand 1. Blood 99:946.
Thatte, A., S. Ficarro, K. R. Snapp, M. K. Wild, D. Vestweber, D. F. Hunt, and K. F. Ley. 2002. Binding of function-blocking mAbs to mouse and human P-selectin glycoprotein ligand-1 peptides with and without tyrosine sulfation. Journal of Leukocyte Biology 72:470.
Lühn, K.*, M. K. Wild*, M. Eckhardt, R. Gerardy-Schahn, and D. Vestweber. 2001. The gene defective in leukocyte adhesion deficiency II encodes a putative GDP-fucose transporter. Nature Genetics28:69.
Rösch, M., H. Herzner, W. Dippold, M. Wild, D. Vestweber, and H. Kunz. 2001. Synthetic Inhibitors of Cell Adhesion: A Glycopeptide from E-Selectin Ligand 1 (ESL-1) with the Arabino Sialyl Lewis(x) Structure. Angewandte Chemie International Edition 40:3836.
Wild, M. K., M. C. Huang, U. Schulze-Horsel, P. A. van der Merwe, and D. Vestweber. 2001. Affinity, kinetics, and thermodynamics of E-selectin binding to E-selectin ligand-1. Journal of Biological Chemistry 276:31602.
Vanhoutte, D., M. Schellings, M. Götte, V. Herias, M. K. Wild, D. Vestweber, M.A. Stepp, F. Van de Werf, P. Carmeliet, Y.M. Pinto, S. Heymanns. 2007. Increased syndecan-1 protects against cardiac dilation and dysfunction after myocardial infarction. Circulation, 115:475.
Henschke, S., N. N. Pawlowski, M. K. Wild, A. J. Kroesen, M. Zeitz, and J. C. Hoffmann. 2006. Lamina propria T cell activation: role of costimulatory molecule CD2 and its cytoplasmic tail for the regulation of proliferation and apoptosis. Int. J. Colorectal Disease 21:321.
Wild, M. K., A. Cambiaggi, M. H. Brown, E. A. Davies, H. Ohno, T. Saito, and P. A. van der Merwe. 1999. Dependence of T cell antigen recognition on the dimensions of an accessory receptor-ligand complex. Journal of Experimental Medicine 190:31.
Wild, M. K.*, W. Strittmatter*, S. Matzku, B. Schraven, and S. C. Meuer. 1999. Tumor therapy with bispecific antibody: the targeting and triggering steps can be separated employing a CD2-based strategy. Journal of Immunology 163:2064.
Davis, S. J., S. Ikemizu, M. K. Wild, and P. A. van der Merwe. 1998. CD2 and the nature of protein interactions mediating cell-cell recognition. Immunological Reviews 163:217.
Wild, M. K., A. M. Verhagen, S. C. Meuer, and B. Schraven. 1997. The receptor function of CD2 in human CD2 transgenic mice is based on highly conserved associations with signal transduction molecules. Cellular Immunology 180:168.
Verhagen, A. M., B. Schraven, M. Wild, R. Wallich, and S. C. Meuer. 1996. Differential interaction of the CD2 extracellular and intracellular domains with the tyrosine phosphatase CD45 and the zeta chain of the TCR/CD3/zeta complex. European Journal of Immunology 26:2841.
Wesselborg, S., U. Prüfer, M. Wild, B. Schraven, S. C. Meuer, and D. Kabelitz. 1993. Triggering via the alternative CD2 pathway induces apoptosis in activated human T lymphocytes. European Journal of Immunology 23:2707.
Schraven, B., M. Wild, H. Kirchgessner, B. Siebert, R. Wallich, S. Henning, Y. Samstag, and S. C. Meuer. 1993. Alterations of CD2 association with T cell receptor signaling molecules in "CD2 unresponsive" human T lymphocytes. European Journal of Immunology 23:119.
