Steven Rosen | University of California, San Francisco (original) (raw)

Papers by Steven Rosen

Research paper thumbnail of High endothelial venules through a transcriptomics lens

Research paper thumbnail of A HEV-restricted sulfotransferase is expressed in rheumatoid arthritis synovium and is induced by lymphotoxin-alpha/beta and TNF-alpha in cultured endothelial cells

BMC immunology, 2005

The recruitment of lymphocytes to secondary lymphoid organs relies on interactions of circulating... more The recruitment of lymphocytes to secondary lymphoid organs relies on interactions of circulating cells with high endothelial venules (HEV). HEV are exclusive to these organs under physiological conditions, but they can develop in chronically-inflamed tissues. The interaction of L-selectin on lymphocytes with sulfated glycoprotein ligands on HEV results in lymphocyte rolling, which represents the initial step in lymphocyte homing. HEV expression of GlcNAc6ST-2 (also known as HEC-GlcNAc6ST, GST-3, LSST or CHST4), an HEV-restricted sulfotransferase, is essential for the elaboration of L-selectin functional ligands as well as a critical epitope recognized by MECA-79 mAb. We examined the expression of GlcNAc6ST-2 in relationship to the MECA-79 epitope in rheumatoid arthritis (RA) synovial vessels. Expression of GlcNAc6ST-2 was specific to RA synovial tissues as compared to osteoarthritis synovial tissues and localized to endothelial cells of HEV-like vessels and small flat-walled vessel...

Research paper thumbnail of Sulfotransferases of two specificities function in the reconstitution of high endothelial cell ligands for L-selectin

Journal of Cell Biology, 1999

L-selectin, a lectin-like receptor, mediates rolling of lymphocytes on high endothelial venules (... more L-selectin, a lectin-like receptor, mediates rolling of lymphocytes on high endothelial venules (HEVs) in secondary lymphoid organs by interacting with HEV ligands. These ligands consist of a complex of sialomucins, candidates for which are glycosylationdependent cell adhesion molecule 1 (GlyCAM-1), CD34, and podocalyxin. The ligands must be sialylated, fucosylated, and sulfated for optimal recognition by L-selectin. Our previous structural characterization of GlyCAM-1 has demonstrated two sulfation modifications, Gal-6-sulfate and GlcNAc-6-sulfate in the context of sialyl Lewis x. We now report the cloning of a Gal-6-sulfotransferase and a GlcNAc-6-sulfotrans-ferase, which can modify GlyCAM-1 and CD34. The Gal-6-sulfotransferase shows a wide tissue distribution. In contrast, the GlcNAc-6-sulfotransferase is highly restricted to HEVs, as revealed by Northern analysis and in situ hybridization. Expression of either enzyme in Chinese hamster ovary cells, along with CD34 and fucosyltransferase VII, results in ligand activity, as detected by binding of an L-selectin/IgM chimera. When coexpressed, the two sulfotransferases synergize to produce strongly enhanced chimera binding.

Research paper thumbnail of GIyCAM-1 a Physiologic Ligand for L-Selectin Activates Integrins on Naive Peripheral Lymphocytes

Research paper thumbnail of Peripheral lymph node homing receptor (LECAM-1)

Research paper thumbnail of Receptors involved in lymphocyte homing: relationship between a carbohydrate-binding receptor and the MEL-14 antigen

The Journal of Cell Biology, 1987

Blood-borne lymphocytes extravasate in large numbers within peripheral lymph nodes (PN) and other... more Blood-borne lymphocytes extravasate in large numbers within peripheral lymph nodes (PN) and other secondary lymphoid organs. It has been proposed that the initiation of extravasation is based upon a family of cell adhesion molecules (homing receptors) that mediate lymphocyte attachment to specialized high endothelial venules (HEV) within the lymphoid tissues. A putative homing receptor has been identified by the monoclonal antibody, MEL-14, which recognizes an 80-90-kD glycoprotein on the surface of mouse lymphocytes and blocks the attachment of lymphocytes to PN HEV. In a companion study we characterize a carbohydrate-binding receptor on the surface of mouse lymphocytes that also appears to be involved in the interaction of lymphocytes with PN HEV. This receptor selectively binds to fluorescent beads derivatized with PPME, a polysaccharide rich in mannose-6phosphate. In this report we examine the relationship

Research paper thumbnail of Direct demonstration of the lectin activity of gp90MEL, a lymphocyte homing receptor

The Journal of Cell Biology, 1990

Considerable evidence implicates gp90 MEL as a lymphocyte homing receptor mediating lymphocyte at... more Considerable evidence implicates gp90 MEL as a lymphocyte homing receptor mediating lymphocyte attachment to high endothelial venules of lymph nodes in mouse. The protein appears to function as a calcium-dependent, lectin-like receptor as inferred primarily by the ability of specific carbohydrates to block its function and by the presence of a calcium-type lectin domain in its primary sequence. An ELISA assay is described which provides the first demonstration that the isolated protein has lectin activity and allows a further definition of its carbohydrate specificity. In addition to the monosaccharides mannose-6-phosphate and fructose-I-phosphate, ligand activity is shown for the sulfated glycolipid, sulfatide, and for two sulfated fucose-containing polysaccharides (fucoidin and egg jelly coat) from nonmammalian sources.

Research paper thumbnail of Demonstration that a lectin-like receptor (gp90MEL) directly mediates adhesion of lymphocytes to high endothelial venules of lymph nodes

The Journal of Cell Biology, 1989

Lymphocyte migration from the blood into 1. Abbreviations used in this paper: HEV, high endotheli... more Lymphocyte migration from the blood into 1. Abbreviations used in this paper: HEV, high endothelial venules; PN, peripheral lymph node; PP, Peyer's patch.

Research paper thumbnail of Teratocarcinoma stem cell adhesion: the role of divalent cations and a cell surface lectin

The Journal of Cell Biology, 1983

We describe two additive systems of intercellular adhesion in teratocarcinoma stem cells (Nulli c... more We describe two additive systems of intercellular adhesion in teratocarcinoma stem cells (Nulli cell line). One component is divalent cation-dependent (Ca ++ or Mg ÷÷) and the other involves a cell surface fucan/mannan-specific lectin, previously identified on stem cells by an erythrocyte rosetting assay. The existence of these two systems is inferred from the observation that reaggregation of stem cells was partially inhibited by the removal of divalent cations or by the presence of lectin inhibitors such as fucoidan, but reaggregation was completely blocked when the two conditions were combined. Our results are related to recent work describing a calcium-dependent system of intercellular adhesion in teratocarcinoma stem cells.

Research paper thumbnail of Binding of L-selectin to the vascular sialomucin CD34

Science, 1993

The adhesive interactions between leukocyte L-selectin and the endothelium are involved in the mi... more The adhesive interactions between leukocyte L-selectin and the endothelium are involved in the migration of lymphocytes through peripheral lymph nodes and of neutrophils to sites of inflammation. A recombinant L-selectin stains high endothelial venules (HEVs) in lymph nodes and recognizes sulfated carbohydrates found on two endothelial glycoproteins, Sgp50 and Sgp90. Amino acid sequencing of purified Sgp90 revealed a protein core identical to that CD34, a sialomucin expressed on hematopoietic stem cells and endothelium. A polyclonal antiserum to recombinant murine CD34 stains peripheral lymph node endothelium and recognizes Sgp90 that is functionally bound by L-selectin. Thus, an HEV glycoform of CD34 can function as a ligand for L-selectin.

Research paper thumbnail of Sulf-2, a Proangiogenic Heparan Sulfate Endosulfatase, Is Upregulated in Breast Cancer

Neoplasia, 2005

Sulf-2 is an endosulfatase with activity against glucosamine-6-sulfate modifications within subre... more Sulf-2 is an endosulfatase with activity against glucosamine-6-sulfate modifications within subregions of intact heparin. The enzyme has the potential to modify the sulfation status of extracellular heparan sulfate proteoglycan (HSPG) glycosaminoglycan chains and thereby to regulate interactions with HSPG-binding proteins. In the present investigation, data mining from published studies was employed to establish Sulf-2 mRNA upregulation in human breast cancer. We further found that cultured breast carcinoma cells expressed Sulf-2 mRNA and released enzymatically active proteins into conditioned medium. In two mouse models of mammary carcinoma, Sulf-2 mRNA was upregulated in comparison to its expression in normal mammary gland. Although mRNA was present in normal tissues, Sulf-2 protein was undetectable; it was, however, detected in some premalignant lesions and in tumors. The protein was localized to the epithelial cells of the tumors. In support of the possible mechanistic relevance of Sulf-2 upregulation in tumors, purified recombinant Sulf-2 promoted angiogenesis in the chick chorioallantoic membrane assay.

Research paper thumbnail of Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs

Nature Immunology, 2007

P-selectin glycoprotein ligand 1 (PSGL-1) is central to the trafficking of immune effector cells ... more P-selectin glycoprotein ligand 1 (PSGL-1) is central to the trafficking of immune effector cells to areas of inflammation through direct interactions with P-selectin, E-selectin and L-selectin. Here we show that PSGL-1 was also required for efficient homing of resting T cells to secondary lymphoid organs but functioned independently of selectin binding. PSGL-1 mediated an enhanced chemotactic T cell response to the secondary lymphoid organ chemokines CCL21 and CCL19 but not to CXCL12 or to inflammatory chemokines. Our data show involvement of PSGL-1 in facilitating the entry of T cells into secondary lymphoid organs, thereby demonstrating the bifunctional nature of this molecule.

Research paper thumbnail of A major class of L-selectin ligands is eliminated in mice deficient in two sulfotransferases expressed in high endothelial venules

Nature Immunology, 2005

The interaction of L-selectin on lymphocytes with sulfated ligands on high endothelial venules le... more The interaction of L-selectin on lymphocytes with sulfated ligands on high endothelial venules leads to rolling and is critical for recruitment of lymphocytes into peripheral lymph nodes. Peripheral node addressin represents a class of L-selectin ligands recognized by the function-blocking monoclonal antibody MECA-79. Its epitope overlaps with sialyl 6-sulfo Lewis X, an L-selectin recognition determinant. Here, mice lacking two N-acetylglucosamine-6-O-sulfotransferases (GlcNAc6ST-1 and GlcNAc6ST-2) demonstrated elimination of both peripheral node addressin and sialyl 6-sulfo Lewis X in high endothelial venules, considerably reduced lymphocyte homing to peripheral lymph nodes and reduced sticking of lymphocytes along high endothelial venules. Our results establish an essential function for the sulfotransferases in L-selectin ligand synthesis and may have relevance for therapy of inflammatory diseases.

Research paper thumbnail of Autotaxin, an ectoenzyme that produces lysophosphatidic acid, promotes the entry of lymphocytes into secondary lymphoid organs

Nature Immunology, 2008

The extracellular lysophospholipase D autotaxin (ATX) and its product, lysophosphatidic acid, hav... more The extracellular lysophospholipase D autotaxin (ATX) and its product, lysophosphatidic acid, have diverse functions in development and cancer, but little is known about their functions in the immune system. Here we found that ATX had high expression in the high endothelial venules of lymphoid organs and was secreted. Chemokine-activated lymphocytes expressed receptors with enhanced affinity for ATX, which provides a mechanism for targeting the secreted ATX to lymphocytes undergoing recruitment. Lysophosphatidic acid induced chemokinesis in T cells. Intravenous injection of enzymatically inactive ATX attenuated the homing of T cells to lymphoid tissues, probably through competition with endogenous ATX and exertion of a dominant negative effect. Our results support the idea of a new and general step in the homing cascade in which the ectoenzyme ATX facilitates the entry of lymphocytes into lymphoid organs.

Research paper thumbnail of Gene Trap Disruption of the Mouse Heparan Sulfate 6-O-Endosulfatase Gene, Sulf2

Molecular and Cellular Biology, 2007

Heparan sulfate (HS) chains are found in the extracellular matrix, covalently linked to core prot... more Heparan sulfate (HS) chains are found in the extracellular matrix, covalently linked to core proteins collectively termed heparan sulfate proteoglycans (HSPGs). A wealth of data has demonstrated roles for HSPGs in the regulation of many cell surface signaling pathways that are crucial during development. Variations in the sulfation pattern along the HS chains influence their ability to interact with molecules such as growth factors, chemokines, morphogens, and adhesion molecules. Sulf1 and Sulf2 are members of a class of recently identified genes that encode heparan sulfate 6-O-endosulfatases (Sulf genes). The removal of 6-O-sulfate from HS via SULF activity influences the function of many factors, including Wnt, fibroblast growth factor, hepatocyte growth factor, heparin-binding epidermal growth factor, and bone morphogenetic protein. Given their possible developmental roles, we have examined Sulf gene expression during mouse embryogenesis. The two Sulf genes are expressed in a broad range of tissues throughout development with largely nonoverlapping expression patterns. Sulf2 transcripts are expressed in the lung, heart, placenta, and ribs. We generated a mouse line possessing a gene trap disruption of the Sulf2 gene. Mice homozygous for the Sulf2 gene trap allele are viable and fertile and have no major developmental defects on several genetic backgrounds. However, we observed strain-specific, nonpenetrant defects affecting viability, lung development, and growth in Sulf2 homozygous animals. These data suggest that Sulf2 may have roles in several tissues but that there is compensation by and/or redundancy with Sulf1.

Research paper thumbnail of Differential gene expression profile of human tonsil high endothelial cells: implications for lymphocyte trafficking

Journal of Leukocyte Biology, 2003

Lymphocyte recirculation is dependent on the interactions of adhesion and signaling molecules exp... more Lymphocyte recirculation is dependent on the interactions of adhesion and signaling molecules expressed on lymphocytes and their partners on high endothelial cells (HEC). Many of the events in this process have yet to be molecularly characterized. To identify novel HEC-specific proteins with potential function in the recruitment cascade, we sequenced a normalized human tonsil HEC cDNA library (generated from an inflamed tonsil) from which lymphocyte and human umbilical vein endothelial cell cDNAs had been subtracted. One-thousand forty-nine sequences were analyzed. All but three mapped to known cDNAs or genomic DNAs. The two most abundant transcripts encoded ␣2-macroglobulin and hevin. The nextabundant transcripts encoded several other protease inhibitors, making this protein class the most prominent in HEC. Several endothelial-specific transcripts were also identified, including those encoding E-selectin, vascular cell adhesion molecule-1, vascular endothelial-junctional adhesion molecule, and platelet-endothelial cell adhesion molecule-1. The library contains a great diversity of transcripts, and studies of the encoded proteins will provide further insight into the complex biology of these specialized endothelial cells. J. Leukoc. Biol. 75: 910 -927; 2004.

Research paper thumbnail of Sulfation-dependent recognition of high endothelial venules (HEV)- ligands by L-selectin and MECA 79, and adhesion-blocking monoclonal antibody

Journal of Experimental Medicine, 1994

L-sdectin is a lectin-like receptor that mediates the attachment of lymphocytes to high endotheli... more L-sdectin is a lectin-like receptor that mediates the attachment of lymphocytes to high endothelial venules (HEV) of lymph nodes during the process of lymphocyte recirculation. Two sulfated, mucin-like glycoproteins known as Sgp50/GlyCAM-1 and Sgp90/CD34 have previously been identified as HEV-associated ligands for L-selectin. These proteins were originally detected with an L-selectin/Ig chimera called LEC-IgG. GIyCAM-1 and CD34 are also recognized by an antiperipheral node addressin (PNAd) mAb called MECA 79, which blocks L-selectin-dependent adhesion and selectively stains lymph node HEV. The present study compares the requirements for the binding of MECA 79 and LEC-IgG to HEV-ligands. Whereas desialylation of GlyCAM-1 and CD34 drastically reduced binding to LEC-IgG, this treatment enhanced the binding of GlyCAM-1 to MECA 79. In contrast, the binding of both MECA 79 and LEC-IgG to GlyCAM-1 and CD34 was greatly decreased when the sulfation of these ligands was reduced with chlorate, a metabolic inhibitor of sulfation. Because MECA 79 stains HEV-like vessels at various sites of inflammation, recognition by L-selectin of ligands outside of secondary lymphoid organs may depend on sulfation. In addition to their reactivity with GlyCAM-1 and CD34, both MECA 79 and LEC-IgG recognize an independent molecule of ~200 kD in a sulfate-dependent manner. Thus, this molecule, which we designate Sgp200, is an additional ligand for L-selectin.

Research paper thumbnail of Identification of Podocalyxin-like Protein as a High Endothelial Venule Ligand for L-selectin: Parallels to CD34

Journal of Experimental Medicine, 1998

The leukocyte adhesion molecule, L-selectin, mediates the recruitment of lymphocytes to secondary... more The leukocyte adhesion molecule, L-selectin, mediates the recruitment of lymphocytes to secondary lymphoid organs via interactions with specific ligands presented on high endothelial venules (HEV). Although the HEV-derived ligands for L-selectin are still incompletely defined, they share a common sialomucin-like structure which is thought to present clustered oligosaccharides to the lectin domain of L-selectin. Podocalyxin-like protein (PCLP) is a transmembrane sialomucin that is similar in structure to the well-characterized L-selectin ligand CD34. PCLP has been shown previously to be expressed on the foot processes of podocytes in the kidney glomerulus as well as on vascular endothelium at some sites. We have determined that PCLP is present on HEV, where it binds to both recombinant L-selectin and the HEVspecific monoclonal antibody MECA-79. Furthermore, purified HEV-derived PCLP is able to support the tethering and rolling of lymphocytes under physiological flow conditions in vitro. These results suggest a novel function for PCLP as an adhesion molecule and allow the definition of conserved structural features in PCLP and CD34, which may be important for L-selectin ligand function. Key words: podocalyxin • L-selectin • CD34 • high endothelial venule • homing 1 Abbreviations used in this paper: GlyCAM-1, glycosylation-dependent cell adhesion molecule-1; HEC, high endothelial cell(s); HEV, high endothelial venule(s); HPRT, hypoxanthine phosphoribosyltransferase; HUVEC, human umbilical vein endothelial cell(s); MAdCAM-1, mucosal addressin cell adhesion molecule-1; OSGE, O -sialoglycoprotein endopeptidase; PBS, Dulbecco's PBS; PBST, PBS-Tween; PBS-TX, PBS-Triton X-100; PCLP, podocalyxin-like protein; PNAd, peripheral node addressin.

Research paper thumbnail of Affinity and Kinetic Analysis of L-selectin (CD62L) Binding to Glycosylation-dependent Cell-adhesion Molecule-1

Journal of Biological Chemistry, 1998

The selectin family of cell adhesion molecules mediates the tethering and rolling of leukocytes o... more The selectin family of cell adhesion molecules mediates the tethering and rolling of leukocytes on blood vessel endothelium. It has been postulated that the molecular basis of this highly dynamic adhesion is the low affinity and rapid kinetics of selectin interactions. However, affinity and kinetic analyses of monomeric selectins binding their natural ligands have not previously been reported. Leukocyte selectin (L-selectin, CD62L) binds preferentially to O-linked carbohydrates present on a small number of mucin-like glycoproteins, such as glycosylation-dependent cell adhesion molecule-1 (Gly-CAM-1), expressed in high endothelial venules. Gly-CAM-1 is a soluble secreted protein which, following binding to CD62L, stimulates ␤ 2 -integrin-mediated adhesion of lymphocytes. Using surface plasmon resonance, we show that a soluble monomeric form of CD62L binds to purified immobilized GlyCAM-1 with a dissociation constant (K d ) of 108 M. CD62L dissociates from GlyCAM-1 with a very fast dissociation rate constant (>10 s ؊1 ) which agrees well with the reported dissociation rate constant of CD62L-mediated leukocyte tethers. The calculated association rate constant is >10 5 M ؊1 s ؊1 . At concentrations just above its mean serum level (ϳ1.5 g/ml or ϳ30 nM), GlyCAM-1 binds multivalently to immobilized CD62L. It follows that soluble GlyCAM-1 may cross-link CD62L when it binds to cells, suggesting a mechanism for signal transduction.

Research paper thumbnail of Low Force Decelerates L-selectin Dissociation from P-selectin Glycoprotein Ligand-1 and Endoglycan

Journal of Biological Chemistry, 2004

Research paper thumbnail of High endothelial venules through a transcriptomics lens

Research paper thumbnail of A HEV-restricted sulfotransferase is expressed in rheumatoid arthritis synovium and is induced by lymphotoxin-alpha/beta and TNF-alpha in cultured endothelial cells

BMC immunology, 2005

The recruitment of lymphocytes to secondary lymphoid organs relies on interactions of circulating... more The recruitment of lymphocytes to secondary lymphoid organs relies on interactions of circulating cells with high endothelial venules (HEV). HEV are exclusive to these organs under physiological conditions, but they can develop in chronically-inflamed tissues. The interaction of L-selectin on lymphocytes with sulfated glycoprotein ligands on HEV results in lymphocyte rolling, which represents the initial step in lymphocyte homing. HEV expression of GlcNAc6ST-2 (also known as HEC-GlcNAc6ST, GST-3, LSST or CHST4), an HEV-restricted sulfotransferase, is essential for the elaboration of L-selectin functional ligands as well as a critical epitope recognized by MECA-79 mAb. We examined the expression of GlcNAc6ST-2 in relationship to the MECA-79 epitope in rheumatoid arthritis (RA) synovial vessels. Expression of GlcNAc6ST-2 was specific to RA synovial tissues as compared to osteoarthritis synovial tissues and localized to endothelial cells of HEV-like vessels and small flat-walled vessel...

Research paper thumbnail of Sulfotransferases of two specificities function in the reconstitution of high endothelial cell ligands for L-selectin

Journal of Cell Biology, 1999

L-selectin, a lectin-like receptor, mediates rolling of lymphocytes on high endothelial venules (... more L-selectin, a lectin-like receptor, mediates rolling of lymphocytes on high endothelial venules (HEVs) in secondary lymphoid organs by interacting with HEV ligands. These ligands consist of a complex of sialomucins, candidates for which are glycosylationdependent cell adhesion molecule 1 (GlyCAM-1), CD34, and podocalyxin. The ligands must be sialylated, fucosylated, and sulfated for optimal recognition by L-selectin. Our previous structural characterization of GlyCAM-1 has demonstrated two sulfation modifications, Gal-6-sulfate and GlcNAc-6-sulfate in the context of sialyl Lewis x. We now report the cloning of a Gal-6-sulfotransferase and a GlcNAc-6-sulfotrans-ferase, which can modify GlyCAM-1 and CD34. The Gal-6-sulfotransferase shows a wide tissue distribution. In contrast, the GlcNAc-6-sulfotransferase is highly restricted to HEVs, as revealed by Northern analysis and in situ hybridization. Expression of either enzyme in Chinese hamster ovary cells, along with CD34 and fucosyltransferase VII, results in ligand activity, as detected by binding of an L-selectin/IgM chimera. When coexpressed, the two sulfotransferases synergize to produce strongly enhanced chimera binding.

Research paper thumbnail of GIyCAM-1 a Physiologic Ligand for L-Selectin Activates Integrins on Naive Peripheral Lymphocytes

Research paper thumbnail of Peripheral lymph node homing receptor (LECAM-1)

Research paper thumbnail of Receptors involved in lymphocyte homing: relationship between a carbohydrate-binding receptor and the MEL-14 antigen

The Journal of Cell Biology, 1987

Blood-borne lymphocytes extravasate in large numbers within peripheral lymph nodes (PN) and other... more Blood-borne lymphocytes extravasate in large numbers within peripheral lymph nodes (PN) and other secondary lymphoid organs. It has been proposed that the initiation of extravasation is based upon a family of cell adhesion molecules (homing receptors) that mediate lymphocyte attachment to specialized high endothelial venules (HEV) within the lymphoid tissues. A putative homing receptor has been identified by the monoclonal antibody, MEL-14, which recognizes an 80-90-kD glycoprotein on the surface of mouse lymphocytes and blocks the attachment of lymphocytes to PN HEV. In a companion study we characterize a carbohydrate-binding receptor on the surface of mouse lymphocytes that also appears to be involved in the interaction of lymphocytes with PN HEV. This receptor selectively binds to fluorescent beads derivatized with PPME, a polysaccharide rich in mannose-6phosphate. In this report we examine the relationship

Research paper thumbnail of Direct demonstration of the lectin activity of gp90MEL, a lymphocyte homing receptor

The Journal of Cell Biology, 1990

Considerable evidence implicates gp90 MEL as a lymphocyte homing receptor mediating lymphocyte at... more Considerable evidence implicates gp90 MEL as a lymphocyte homing receptor mediating lymphocyte attachment to high endothelial venules of lymph nodes in mouse. The protein appears to function as a calcium-dependent, lectin-like receptor as inferred primarily by the ability of specific carbohydrates to block its function and by the presence of a calcium-type lectin domain in its primary sequence. An ELISA assay is described which provides the first demonstration that the isolated protein has lectin activity and allows a further definition of its carbohydrate specificity. In addition to the monosaccharides mannose-6-phosphate and fructose-I-phosphate, ligand activity is shown for the sulfated glycolipid, sulfatide, and for two sulfated fucose-containing polysaccharides (fucoidin and egg jelly coat) from nonmammalian sources.

Research paper thumbnail of Demonstration that a lectin-like receptor (gp90MEL) directly mediates adhesion of lymphocytes to high endothelial venules of lymph nodes

The Journal of Cell Biology, 1989

Lymphocyte migration from the blood into 1. Abbreviations used in this paper: HEV, high endotheli... more Lymphocyte migration from the blood into 1. Abbreviations used in this paper: HEV, high endothelial venules; PN, peripheral lymph node; PP, Peyer's patch.

Research paper thumbnail of Teratocarcinoma stem cell adhesion: the role of divalent cations and a cell surface lectin

The Journal of Cell Biology, 1983

We describe two additive systems of intercellular adhesion in teratocarcinoma stem cells (Nulli c... more We describe two additive systems of intercellular adhesion in teratocarcinoma stem cells (Nulli cell line). One component is divalent cation-dependent (Ca ++ or Mg ÷÷) and the other involves a cell surface fucan/mannan-specific lectin, previously identified on stem cells by an erythrocyte rosetting assay. The existence of these two systems is inferred from the observation that reaggregation of stem cells was partially inhibited by the removal of divalent cations or by the presence of lectin inhibitors such as fucoidan, but reaggregation was completely blocked when the two conditions were combined. Our results are related to recent work describing a calcium-dependent system of intercellular adhesion in teratocarcinoma stem cells.

Research paper thumbnail of Binding of L-selectin to the vascular sialomucin CD34

Science, 1993

The adhesive interactions between leukocyte L-selectin and the endothelium are involved in the mi... more The adhesive interactions between leukocyte L-selectin and the endothelium are involved in the migration of lymphocytes through peripheral lymph nodes and of neutrophils to sites of inflammation. A recombinant L-selectin stains high endothelial venules (HEVs) in lymph nodes and recognizes sulfated carbohydrates found on two endothelial glycoproteins, Sgp50 and Sgp90. Amino acid sequencing of purified Sgp90 revealed a protein core identical to that CD34, a sialomucin expressed on hematopoietic stem cells and endothelium. A polyclonal antiserum to recombinant murine CD34 stains peripheral lymph node endothelium and recognizes Sgp90 that is functionally bound by L-selectin. Thus, an HEV glycoform of CD34 can function as a ligand for L-selectin.

Research paper thumbnail of Sulf-2, a Proangiogenic Heparan Sulfate Endosulfatase, Is Upregulated in Breast Cancer

Neoplasia, 2005

Sulf-2 is an endosulfatase with activity against glucosamine-6-sulfate modifications within subre... more Sulf-2 is an endosulfatase with activity against glucosamine-6-sulfate modifications within subregions of intact heparin. The enzyme has the potential to modify the sulfation status of extracellular heparan sulfate proteoglycan (HSPG) glycosaminoglycan chains and thereby to regulate interactions with HSPG-binding proteins. In the present investigation, data mining from published studies was employed to establish Sulf-2 mRNA upregulation in human breast cancer. We further found that cultured breast carcinoma cells expressed Sulf-2 mRNA and released enzymatically active proteins into conditioned medium. In two mouse models of mammary carcinoma, Sulf-2 mRNA was upregulated in comparison to its expression in normal mammary gland. Although mRNA was present in normal tissues, Sulf-2 protein was undetectable; it was, however, detected in some premalignant lesions and in tumors. The protein was localized to the epithelial cells of the tumors. In support of the possible mechanistic relevance of Sulf-2 upregulation in tumors, purified recombinant Sulf-2 promoted angiogenesis in the chick chorioallantoic membrane assay.

Research paper thumbnail of Interaction of the selectin ligand PSGL-1 with chemokines CCL21 and CCL19 facilitates efficient homing of T cells to secondary lymphoid organs

Nature Immunology, 2007

P-selectin glycoprotein ligand 1 (PSGL-1) is central to the trafficking of immune effector cells ... more P-selectin glycoprotein ligand 1 (PSGL-1) is central to the trafficking of immune effector cells to areas of inflammation through direct interactions with P-selectin, E-selectin and L-selectin. Here we show that PSGL-1 was also required for efficient homing of resting T cells to secondary lymphoid organs but functioned independently of selectin binding. PSGL-1 mediated an enhanced chemotactic T cell response to the secondary lymphoid organ chemokines CCL21 and CCL19 but not to CXCL12 or to inflammatory chemokines. Our data show involvement of PSGL-1 in facilitating the entry of T cells into secondary lymphoid organs, thereby demonstrating the bifunctional nature of this molecule.

Research paper thumbnail of A major class of L-selectin ligands is eliminated in mice deficient in two sulfotransferases expressed in high endothelial venules

Nature Immunology, 2005

The interaction of L-selectin on lymphocytes with sulfated ligands on high endothelial venules le... more The interaction of L-selectin on lymphocytes with sulfated ligands on high endothelial venules leads to rolling and is critical for recruitment of lymphocytes into peripheral lymph nodes. Peripheral node addressin represents a class of L-selectin ligands recognized by the function-blocking monoclonal antibody MECA-79. Its epitope overlaps with sialyl 6-sulfo Lewis X, an L-selectin recognition determinant. Here, mice lacking two N-acetylglucosamine-6-O-sulfotransferases (GlcNAc6ST-1 and GlcNAc6ST-2) demonstrated elimination of both peripheral node addressin and sialyl 6-sulfo Lewis X in high endothelial venules, considerably reduced lymphocyte homing to peripheral lymph nodes and reduced sticking of lymphocytes along high endothelial venules. Our results establish an essential function for the sulfotransferases in L-selectin ligand synthesis and may have relevance for therapy of inflammatory diseases.

Research paper thumbnail of Autotaxin, an ectoenzyme that produces lysophosphatidic acid, promotes the entry of lymphocytes into secondary lymphoid organs

Nature Immunology, 2008

The extracellular lysophospholipase D autotaxin (ATX) and its product, lysophosphatidic acid, hav... more The extracellular lysophospholipase D autotaxin (ATX) and its product, lysophosphatidic acid, have diverse functions in development and cancer, but little is known about their functions in the immune system. Here we found that ATX had high expression in the high endothelial venules of lymphoid organs and was secreted. Chemokine-activated lymphocytes expressed receptors with enhanced affinity for ATX, which provides a mechanism for targeting the secreted ATX to lymphocytes undergoing recruitment. Lysophosphatidic acid induced chemokinesis in T cells. Intravenous injection of enzymatically inactive ATX attenuated the homing of T cells to lymphoid tissues, probably through competition with endogenous ATX and exertion of a dominant negative effect. Our results support the idea of a new and general step in the homing cascade in which the ectoenzyme ATX facilitates the entry of lymphocytes into lymphoid organs.

Research paper thumbnail of Gene Trap Disruption of the Mouse Heparan Sulfate 6-O-Endosulfatase Gene, Sulf2

Molecular and Cellular Biology, 2007

Heparan sulfate (HS) chains are found in the extracellular matrix, covalently linked to core prot... more Heparan sulfate (HS) chains are found in the extracellular matrix, covalently linked to core proteins collectively termed heparan sulfate proteoglycans (HSPGs). A wealth of data has demonstrated roles for HSPGs in the regulation of many cell surface signaling pathways that are crucial during development. Variations in the sulfation pattern along the HS chains influence their ability to interact with molecules such as growth factors, chemokines, morphogens, and adhesion molecules. Sulf1 and Sulf2 are members of a class of recently identified genes that encode heparan sulfate 6-O-endosulfatases (Sulf genes). The removal of 6-O-sulfate from HS via SULF activity influences the function of many factors, including Wnt, fibroblast growth factor, hepatocyte growth factor, heparin-binding epidermal growth factor, and bone morphogenetic protein. Given their possible developmental roles, we have examined Sulf gene expression during mouse embryogenesis. The two Sulf genes are expressed in a broad range of tissues throughout development with largely nonoverlapping expression patterns. Sulf2 transcripts are expressed in the lung, heart, placenta, and ribs. We generated a mouse line possessing a gene trap disruption of the Sulf2 gene. Mice homozygous for the Sulf2 gene trap allele are viable and fertile and have no major developmental defects on several genetic backgrounds. However, we observed strain-specific, nonpenetrant defects affecting viability, lung development, and growth in Sulf2 homozygous animals. These data suggest that Sulf2 may have roles in several tissues but that there is compensation by and/or redundancy with Sulf1.

Research paper thumbnail of Differential gene expression profile of human tonsil high endothelial cells: implications for lymphocyte trafficking

Journal of Leukocyte Biology, 2003

Lymphocyte recirculation is dependent on the interactions of adhesion and signaling molecules exp... more Lymphocyte recirculation is dependent on the interactions of adhesion and signaling molecules expressed on lymphocytes and their partners on high endothelial cells (HEC). Many of the events in this process have yet to be molecularly characterized. To identify novel HEC-specific proteins with potential function in the recruitment cascade, we sequenced a normalized human tonsil HEC cDNA library (generated from an inflamed tonsil) from which lymphocyte and human umbilical vein endothelial cell cDNAs had been subtracted. One-thousand forty-nine sequences were analyzed. All but three mapped to known cDNAs or genomic DNAs. The two most abundant transcripts encoded ␣2-macroglobulin and hevin. The nextabundant transcripts encoded several other protease inhibitors, making this protein class the most prominent in HEC. Several endothelial-specific transcripts were also identified, including those encoding E-selectin, vascular cell adhesion molecule-1, vascular endothelial-junctional adhesion molecule, and platelet-endothelial cell adhesion molecule-1. The library contains a great diversity of transcripts, and studies of the encoded proteins will provide further insight into the complex biology of these specialized endothelial cells. J. Leukoc. Biol. 75: 910 -927; 2004.

Research paper thumbnail of Sulfation-dependent recognition of high endothelial venules (HEV)- ligands by L-selectin and MECA 79, and adhesion-blocking monoclonal antibody

Journal of Experimental Medicine, 1994

L-sdectin is a lectin-like receptor that mediates the attachment of lymphocytes to high endotheli... more L-sdectin is a lectin-like receptor that mediates the attachment of lymphocytes to high endothelial venules (HEV) of lymph nodes during the process of lymphocyte recirculation. Two sulfated, mucin-like glycoproteins known as Sgp50/GlyCAM-1 and Sgp90/CD34 have previously been identified as HEV-associated ligands for L-selectin. These proteins were originally detected with an L-selectin/Ig chimera called LEC-IgG. GIyCAM-1 and CD34 are also recognized by an antiperipheral node addressin (PNAd) mAb called MECA 79, which blocks L-selectin-dependent adhesion and selectively stains lymph node HEV. The present study compares the requirements for the binding of MECA 79 and LEC-IgG to HEV-ligands. Whereas desialylation of GlyCAM-1 and CD34 drastically reduced binding to LEC-IgG, this treatment enhanced the binding of GlyCAM-1 to MECA 79. In contrast, the binding of both MECA 79 and LEC-IgG to GlyCAM-1 and CD34 was greatly decreased when the sulfation of these ligands was reduced with chlorate, a metabolic inhibitor of sulfation. Because MECA 79 stains HEV-like vessels at various sites of inflammation, recognition by L-selectin of ligands outside of secondary lymphoid organs may depend on sulfation. In addition to their reactivity with GlyCAM-1 and CD34, both MECA 79 and LEC-IgG recognize an independent molecule of ~200 kD in a sulfate-dependent manner. Thus, this molecule, which we designate Sgp200, is an additional ligand for L-selectin.

Research paper thumbnail of Identification of Podocalyxin-like Protein as a High Endothelial Venule Ligand for L-selectin: Parallels to CD34

Journal of Experimental Medicine, 1998

The leukocyte adhesion molecule, L-selectin, mediates the recruitment of lymphocytes to secondary... more The leukocyte adhesion molecule, L-selectin, mediates the recruitment of lymphocytes to secondary lymphoid organs via interactions with specific ligands presented on high endothelial venules (HEV). Although the HEV-derived ligands for L-selectin are still incompletely defined, they share a common sialomucin-like structure which is thought to present clustered oligosaccharides to the lectin domain of L-selectin. Podocalyxin-like protein (PCLP) is a transmembrane sialomucin that is similar in structure to the well-characterized L-selectin ligand CD34. PCLP has been shown previously to be expressed on the foot processes of podocytes in the kidney glomerulus as well as on vascular endothelium at some sites. We have determined that PCLP is present on HEV, where it binds to both recombinant L-selectin and the HEVspecific monoclonal antibody MECA-79. Furthermore, purified HEV-derived PCLP is able to support the tethering and rolling of lymphocytes under physiological flow conditions in vitro. These results suggest a novel function for PCLP as an adhesion molecule and allow the definition of conserved structural features in PCLP and CD34, which may be important for L-selectin ligand function. Key words: podocalyxin • L-selectin • CD34 • high endothelial venule • homing 1 Abbreviations used in this paper: GlyCAM-1, glycosylation-dependent cell adhesion molecule-1; HEC, high endothelial cell(s); HEV, high endothelial venule(s); HPRT, hypoxanthine phosphoribosyltransferase; HUVEC, human umbilical vein endothelial cell(s); MAdCAM-1, mucosal addressin cell adhesion molecule-1; OSGE, O -sialoglycoprotein endopeptidase; PBS, Dulbecco's PBS; PBST, PBS-Tween; PBS-TX, PBS-Triton X-100; PCLP, podocalyxin-like protein; PNAd, peripheral node addressin.

Research paper thumbnail of Affinity and Kinetic Analysis of L-selectin (CD62L) Binding to Glycosylation-dependent Cell-adhesion Molecule-1

Journal of Biological Chemistry, 1998

The selectin family of cell adhesion molecules mediates the tethering and rolling of leukocytes o... more The selectin family of cell adhesion molecules mediates the tethering and rolling of leukocytes on blood vessel endothelium. It has been postulated that the molecular basis of this highly dynamic adhesion is the low affinity and rapid kinetics of selectin interactions. However, affinity and kinetic analyses of monomeric selectins binding their natural ligands have not previously been reported. Leukocyte selectin (L-selectin, CD62L) binds preferentially to O-linked carbohydrates present on a small number of mucin-like glycoproteins, such as glycosylation-dependent cell adhesion molecule-1 (Gly-CAM-1), expressed in high endothelial venules. Gly-CAM-1 is a soluble secreted protein which, following binding to CD62L, stimulates ␤ 2 -integrin-mediated adhesion of lymphocytes. Using surface plasmon resonance, we show that a soluble monomeric form of CD62L binds to purified immobilized GlyCAM-1 with a dissociation constant (K d ) of 108 M. CD62L dissociates from GlyCAM-1 with a very fast dissociation rate constant (>10 s ؊1 ) which agrees well with the reported dissociation rate constant of CD62L-mediated leukocyte tethers. The calculated association rate constant is >10 5 M ؊1 s ؊1 . At concentrations just above its mean serum level (ϳ1.5 g/ml or ϳ30 nM), GlyCAM-1 binds multivalently to immobilized CD62L. It follows that soluble GlyCAM-1 may cross-link CD62L when it binds to cells, suggesting a mechanism for signal transduction.

Research paper thumbnail of Low Force Decelerates L-selectin Dissociation from P-selectin Glycoprotein Ligand-1 and Endoglycan

Journal of Biological Chemistry, 2004