Requirement for sialic acid on the endothelial ligand of a lymphocyte homing receptor.

The entry of blood-borne lymphocytes into most secondary lymphoid organs is initiated by a highly specific adhesive interaction with the specialized cuboidal endothelial cells of high endothelial venules (HEV). The adhesive receptors on lymphocytes that dictate interactions with HEV in different lymphoid organs are called homing receptors, signifying their critical role in controlling organ-selective lymphocyte migration. Considerable work has established that the mouse peripheral lymph node homing receptor (pnHR), defined by the mAb MEL-14, functions as a lectin-like adhesive protein. We have previously shown that sialidase treatment of peripheral lymph node (PN) HEV abrogates lymphocyte attachment to the HEV both in vivo and in vitro. We extend this evidence by demonstrating that Limax agglutinin (LA), a sialic acid-specific lectin, when reacted with HEV exposed in cryostat-cut tissue sections, blocks lymphocyte attachment to PN HEV and, unexpectedly, to the HEV of Peyer's patches (PP) as well. Using a recombinant form of the pnHR as a histochemical probe for its cognate adhesive site (HEV-ligand) on PN HEV, we demonstrate that both sialidase and Limax agglutinin functionally inactive this ligand. It is concluded that the requirement for sialic acid is at the level of the pnHR interaction with its HEV ligand. A distinct sialyloligosaccharide may encode the recognition determinant of a PP HEV ligand.

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

The Journal of Cell Biology ◽

10.1083/jcb.109.5.2463 ◽

1989 ◽

Vol 109 (5) ◽

pp. 2463-2469 ◽

Cited By ~ 48

Author(s):

J S Geoffroy ◽

S D Rosen

Keyword(s):

Lymph Node ◽

Lymphoid Organ ◽

Lymphoid Organs ◽

Surface Glycoprotein ◽

Lymphocyte Migration ◽

Peripheral Lymph Node ◽

Adhesive Interaction ◽

High Endothelial Venules ◽

Cell Surface Glycoprotein ◽

Peripheral Lymph

Lymphocyte migration from the blood into most secondary lymphoid organs is initiated by a highly selective adhesive interaction with the endothelium of specialized blood vessels known as high endothelial venules (HEV). The propensity of lymphocytes to migrate to particular lymphoid organs is known as lymphocyte homing, and the receptors on lymphocytes that dictate interactions with HEV at particular anatomical sites are designated "homing receptors". Based upon antibody blockade experiments and cell-type distribution studies, a prominent candidate for the peripheral lymph node homing receptor in mouse is the approximately 90-kD cell surface glycoprotein (gp90MEL) recognized by the monoclonal antibody MEL-14. Previous work, including sequencing of a cDNA encoding for this molecule, supports the possibility that gp90MEL is a calcium-dependent lectin-like receptor. Here, we show that immunoaffinity-purified gp90MEL interacts in a sugar-inhibitable manner with sites on peripheral lymph node HEV and prevents attachment of lymphocytes. Lymphocyte attachment to HEV in Peyer's patches, a gut-associated lymphoid organ, is not affected by gp90MEL. The results demonstrate that gp90MEL, as a lectin-like receptor, directly bridges lymphocytes to the endothelium.

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Identification of a carbohydrate-based endothelial ligand for a lymphocyte homing receptor.

The Journal of Cell Biology ◽

10.1083/jcb.113.5.1213 ◽

1991 ◽

Vol 113 (5) ◽

pp. 1213-1221 ◽

Cited By ~ 183

Author(s):

Y Imai ◽

M S Singer ◽

C Fennie ◽

L A Lasky ◽

S D Rosen

Keyword(s):

Lymph Node ◽

Peripheral Lymph Node ◽

Lymphocyte Homing ◽

High Endothelial Venules ◽

Homing Receptor ◽

Calcium Dependent ◽

Lymph Node Homing ◽

Recombinant Receptor ◽

Peripheral Lymph ◽

Mouse Lymphocytes

Lymphocyte attachment to high endothelial venules within lymph nodes is mediated by the peripheral lymph node homing receptor (pnHR), originally defined on mouse lymphocytes by the MEL-14 mAb. The pnHR is a calcium-dependent lectin-like receptor, a member of the LEC-CAM family of adhesion proteins. Here, using a soluble recombinant form of the homing receptor, we have identified an endothelial ligand for the pnHR as an approximately 50-kD sulfated, fucosylated, and sialylated glycoprotein, which we designate Sgp50 (sulfated glycoprotein of 50 kD). Recombinant receptor binding to this lymph node-specific glycoprotein requires calcium and is inhibitable by specific carbohydrates and by MEL-14 mAb. Sialylation of the component is required for binding. Additionally, the glycoprotein is precipitated by MECA-79, an adhesion-blocking mAb reactive with lymph node HEV. A related glycoprotein of approximately 90 kD (designated as Sgp90) is also identified.

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The human peripheral lymph node vascular addressin is a ligand for LECAM-1, the peripheral lymph node homing receptor.

The Journal of Cell Biology ◽

10.1083/jcb.114.2.343 ◽

1991 ◽

Vol 114 (2) ◽

pp. 343-349 ◽

Cited By ~ 208

Author(s):

E L Berg ◽

M K Robinson ◽

R A Warnock ◽

E C Butcher

Keyword(s):

Lymph Node ◽

Lymphoid Tissues ◽

Dependent Manner ◽

Peripheral Lymph Node ◽

Lymphocyte Homing ◽

High Endothelial Venules ◽

Homing Receptor ◽

Calcium Dependent ◽

Lymph Node Homing ◽

Peripheral Lymph

The trafficking of lymphocytes from the blood and into lymphoid organs is controlled by tissue-selective lymphocyte interactions with specialized endothelial cells lining post capillary venules, in particular the high endothelial venules (HEV) found in lymphoid tissues and sites of chronic inflammation. Lymphocyte interactions with HEV are mediated in part by lymphocyte homing receptors and tissue-specific HEV determinants, the vascular addressins. A peripheral lymph node addressin (PNAd) has been detected immunohistologically in mouse and man by monoclonal antibody MECA-79, which inhibits lymphocyte homing to lymph nodes and lymphocyte binding to lymph node and tonsillar HEV. The human MECA-79 antigen, PNAd, is molecularly distinct from the 65-kD mucosal vascular addressin. The most abundant iodinated species by SDS-PAGE is 105 kD. When affinity isolated and immobilized on glass slides, MECA-79 immunoisolated material binds human and mouse lymphocytes avidly in a calcium dependent manner. Binding is blocked by mAb MECA-79, by antibodies against mouse or human LECAM-1 (the peripheral lymph node homing receptor, the MEL-14 antigen, LAM-1), and by treatment of PNAd with neuraminidase. Expression of LECAM-1 cDNA confers PNAd binding ability on a transfected B cell line. We conclude that LECAM-1 mediates lymphocyte binding to PNAd, an interaction that involves the lectin activity of LECAM-1 and carbohydrate determinants on the addressin.

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Characterization of a human homologue of the murine peripheral lymph node homing receptor.

The Journal of Cell Biology ◽

10.1083/jcb.109.1.421 ◽

1989 ◽

Vol 109 (1) ◽

pp. 421-427 ◽

Cited By ~ 60

Author(s):

B R Bowen ◽

T Nguyen ◽

L A Lasky

Keyword(s):

Cell Adhesion ◽

Lymph Node ◽

Adhesion Molecule ◽

Carbohydrate Binding ◽

Human Homologue ◽

Peripheral Lymph Node ◽

Homing Receptor ◽

Lymph Node Homing ◽

Peripheral Lymph ◽

Human Receptor

Lymphocyte trafficking is a fundamental aspect of the immune system that allows B and T lymphocytes with diverse antigen recognition specificities to be exposed to various antigenic stimuli in spatially distinct regions of an organism. A lymphocyte adhesion molecule that is involved with this trafficking phenomenon has been termed the homing receptor. Previous work (Lasky, L., T. Yednock, M. Singer, D. Dowbenko, C. Fennie, H. Rodriguez, T. Nguyen, S. Stachel, and S. Rosen. 1989. Cell. 56:1045-1055) has characterized a cDNA clone encoding a murine homing receptor that is involved in trafficking of lymphocytes to peripheral lymph nodes. This molecule was found to contain a number of protein motifs, the most intriguing of which was a carbohydrate binding domain, or lectin, that is apparently involved in the adhesive interaction between murine lymphocytes and peripheral lymph node endothelium. In this study, we have used the murine cDNA clone to isolate a human homologue of this peripheral lymph node-specific adhesion molecule. The human receptor was found to be highly homologous to the murine receptor in overall sequence, but showed no sequence similarity to another surface protein that may be involved with human lymphocyte homing, the Hermes glycoprotein. The extracellular region of the human receptor contained an NH2 terminally located carbohydrate binding domain followed by an EGF-like domain and a domain containing two repeats of a complement binding motif. Transient cell transfection assays using the human receptor cDNA showed that it encoded a surface glycoprotein that cross reacted with a polyclonal antibody directed against the murine peripheral lymph node homing receptor. Interestingly, the human receptor showed a high degree of sequence homology to another human cell adhesion glycoprotein, the endothelial cell adhesion molecule ELAM.

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