Robert Sackstein

Dana-Farber Cancer Institute, Boston, Massachusetts, United States

Are you Robert Sackstein?

Claim your profile

Publications (92)573.31 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Whereas DC have increasingly been recognized for their role in activating the inflammatory cascades during IRIs, the mechanisms by which oxidative stress enhances DC activation remain to be explored. We examined the role of oxidative stress on two important features of DC: T cell activation and trafficking. Bone marrow-derived OS-DC were compared with untreated DC. DC exposed to oxidative stress augmented allogeneic T cell proliferation and showed increased migration in a chemotaxis chamber. These results were confirmed by using hypoxanthine and xanthine oxidase as another inducer of oxidative stress. We used OT-II and OT-I mice to assess the effect of oxidative stress on DC activation of OVA-specific CD4(+) and CD8(+) T cells, respectively. Oxidative stress increased DC capacity to promote OVA-specific CD4(+) T cell activity, demonstrated by an increase in their proliferation and production of IFN-γ, IL-6, and IL-2 proinflammatory cytokines. Whereas oxidative stress increased the DC ability to stimulate IFN-γ production by OVA-specific CD8(+) T cells, cellular proliferation and cytotoxicity were not affected. Compared with untreated DC, oxidative stress significantly reduced the capacity of DC to generate Tregs, which were restored by using anti-IL-6. With regard to DC trafficking, whereas oxidative stress increased DC expression of p-Akt and p-NF-κB, targeting PI3Kγ and NF-κB pathways abrogated the observed increase in DC migration. Our data propose novel insights on the activation of DC by oxidative stress and provide rationales for targeted therapies, which can potentially attenuate IRI.
    Journal of leukocyte biology 03/2014; · 4.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Leukocyte adhesion deficiency type-II (LADII) is a hereditary disorder of neutrophil migration caused by mutations in the GDP-fucose transporter gene (SLC35C1). In these patients, inability to generate key fucosylated molecules including sialyl Lewis X leads to leukocytosis and recurrent infections, in addition to short stature and developmental delay. We report two brothers with short stature and developmental delay who are compound heterozygotes for novel mutations in SLC35C1 resulting in partial in vivo defects in fucosylation. Specifically, plasma glycoproteins including IgG demonstrated marked changes in glycoform distribution. While neutrophil rolling on endothelial selectins was partially impeded, residual adhesion proved sufficient to avoid leukocytosis or recurrent infection. These findings demonstrate a surprising degree of immune redundancy in the face of substantial alterations in adhesion molecule expression, while showing that short stature and developmental delay may be the sole presenting signs in this disorder.
    Human Molecular Genetics 01/2014; · 7.69 Impact Factor
  • Source
    Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: The proximate hurdle for cell trafficking to any anatomic site is the initial attachment of circulating cells to target tissue endothelium with sufficient strength to overcome prevailing forces of blood flow. E-selectin, an endothelial molecule that is inducibly expressed at all sites of inflammation, is a potent effector of this primary braking process. This molecule is a member of a family of C-type lectins known as selectins that bind sialofucosylated glycans displayed on either a protein (i.e., glycoprotein) or lipid (i.e., glycolipid) scaffold. On human cells, the predominant E-selectin ligand is a specialized glycoform of CD44 known as hematopoietic cell E-/L-selectin ligand (HCELL). This review focuses on the biology of HCELL/E-selectin interactions in cell migration, and discusses the utility and applicability of glycosyltransferase-programmed stereosubstitution (GPS) for glycoengineering HCELL expression. Without compromising cell viability or native phenotype, this exoglycosylation technology literally "sweetens" CD44, licensing E-selectin-dependent vascular delivery for all cell-based therapeutics.
    Annals of the New York Academy of Sciences 02/2012; 1253:193-200. · 4.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: When refrigerated platelets are rewarmed, they secrete active sialidases, including the lysosomal sialidase Neu1, and express surface Neu3 that remove sialic acid from platelet von Willebrand factor receptor (VWFR), specifically the GPIbα subunit. The recovery and circulation of refrigerated platelets is greatly improved by storage in the presence of inhibitors of sialidases. Desialylated VWFR is also a target for metalloproteinases (MPs), because GPIbα and GPV are cleaved from the surface of refrigerated platelets. Receptor shedding is inhibited by the MP inhibitor GM6001 and does not occur in Adam17(ΔZn/ΔZn) platelets expressing inactive ADAM17. Critically, desialylation in the absence of MP-mediated receptor shedding is sufficient to cause the rapid clearance of platelets from circulation. Desialylation of platelet VWFR therefore triggers platelet clearance and primes GPIbα and GPV for MP-dependent cleavage.
    Blood 11/2011; 119(5):1263-73. · 9.78 Impact Factor
  • Source
    Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: The successful clinical implementation of adoptive cell therapeutics, including bone marrow transplantation and other stem cell-based treatments, depends critically on the ability to deliver cells to sites where they are needed. E-selectin, an endothelial C-type lectin, binds sialofucosylated carbohydrate determinants on its pertinent ligands. This molecule is expressed in a constitutive manner on bone marrow and dermal microvascular endothelium, and inducibly on post-capillary venules at all sites of tissue injury. Engagement of E-selectin with relevant ligand(s) expressed on circulating cells mediates initial "tethering/rolling" endothelial adhesive interactions prerequisite for extravasation of blood-borne cells at any target tissue. Most mammalian cells express high levels of a transmembrane glycoprotein known as CD44. A specialized glycoform of CD44 called "Hematopoietic Cell E-/L-selectin Ligand" (HCELL) is a potent E-selectin ligand expressed on human cells. Under native conditions, HCELL expression is restricted to human hematopoietic stem/progenitor cells. We have developed a technology called "Glycosyltransferase-Programmed Stereosubstitution" (GPS) for custom-modifying CD44 glycans to create HCELL on the surface of living cells. GPS-based glycoengineering of HCELL endows cell migration to endothelial beds expressing E-selectin. Enforced HCELL expression targets human mesenchymal stem cell homing to marrow, licensing transendothelial migration without chemokine signaling via a VLA-4/VCAM-1-dependent "Step 2-bypass pathway." This review presents an historical framework of the homing receptor concept, and will describe the discovery of HCELL, its function as the bone marrow homing receptor, and how enforced expression of this molecule via chemical engineering of CD44 glycans could enable stem cell-based regenerative medicine and other adoptive cell therapeutics.
    Annals of Biomedical Engineering 11/2011; 40(4):766-76. · 3.23 Impact Factor
  • Source
    Pieter P Jacobs, Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: Despite great strides in our knowledge of the genetic and epigenetic changes underlying malignancy, we have limited information on the molecular basis of metastasis. Over 90% of cancer deaths are caused by spread of tumor cells from a primary site to distant organs and tissues, highlighting the pressing need to define the molecular effectors of cancer metastasis. Mounting evidence suggests that circulating tumor cells (CTCs) home to specific tissues by hijacking the normal leukocyte trafficking mechanisms. Cancer cells characteristically express CD44, and there is increasing evidence that hematopoietic cell E-/L-selectin ligand (HCELL), a sialofucosylated glycoform of CD44, serves as the major selectin ligand on cancer cells, allowing interaction of tumor cells with endothelium, leukocytes, and platelets. Here, we review the structural biology of CD44 and of HCELL, and present current data on the function of these molecules in mediating organ-specific homing/metastasis of CTCs.
    FEBS letters 08/2011; 585(20):3148-58. · 3.54 Impact Factor
  • Source
    Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: The homing and egress of hematopoietic stem and progenitor cells (HSPCs) to and from marrow, respectively, and the proliferation and differentiation of HSPCs within marrow are complex processes critically regulated by the ordered expression and function of adhesion molecules that direct key cell-cell and cell-matrix interactions. The integral membrane molecule CD44, known primarily for its role in binding hyaluronic acid, is characteristically expressed on HSPCs. Conspicuously, human HSPCs uniquely display a specialized glycoform of CD44 known as hematopoietic cell E-/L-selectin ligand (HCELL), which is the most potent ligand for both E-selectin and L-selectin expressed on human cells. This review focuses on recent advances in our understanding of the biology of CD44 and HCELL in hematopoiesis. New data indicate that CD44-mediated events in hematopoiesis are more complex than previously imagined. Ex-vivo glycan engineering has established that HCELL serves as a 'bone marrow homing receptor'. Moreover, biochemical studies now show that CD44 forms bimolecular complexes with a variety of membrane proteins, one of which is VLA-4. Engagement of CD44 or of HCELL directly induces VLA-4 activation via G-protein-dependent signaling, triggering a 'step 2-bypass pathway' of cell migration, and extravascular lodgment, in absence of chemokine receptor engagement. Recent studies have further clarified the roles of CD44 and its glycoform HCELL in hematopoietic processes, providing key insights on how targeting these molecules may be beneficial in promoting hematopoiesis and in treating hematologic malignancies.
    Current opinion in hematology 07/2011; 18(4):239-48. · 5.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Although well recognized that expression of E-selectin on marrow microvessels mediates osteotropism of hematopoietic stem/progenitor cells (HSPCs), our knowledge regarding the cognate E-selectin ligand(s) on HSPCs is incomplete. Flow cytometry using E-selectin-Ig chimera (E-Ig) shows that human marrow cells enriched for HSPCs (CD34(+) cells) display greater E-selectin binding than those obtained from mouse (lin(-)/Sca-1(+)/c-kit(+) [LSK] cells). To define the relevant glycoprotein E-selectin ligands, lysates from human CD34(+) and KG1a cells and from mouse LSK cells were immunoprecipitated using E-Ig and resolved by Western blot using E-Ig. In both human and mouse cells, E-selectin ligand reactivity was observed at ~ 120- to 130-kDa region, which contained two E-selectin ligands, the P-selectin glycoprotein ligand-1 glycoform "CLA," and CD43. Human, but not mouse, cells displayed a prominent ~ 100-kDa band, exclusively comprising the CD44 glycoform "HCELL." E-Ig reactivity was most prominent on CLA in mouse cells and on HCELL in human cells. To further assess HCELL's contribution to E-selectin adherence, complementary studies were performed to silence (via CD44 siRNA) or enforce its expression (via exoglycosylation). Under physiologic shear conditions, CD44/HCELL-silenced human cells showed striking decreases (> 50%) in E-selectin binding. Conversely, enforced HCELL expression of LSK cells profoundly increased E-selectin adherence, yielding > 3-fold more marrow homing in vivo. These data define the key glycoprotein E-selectin ligands of human and mouse HSPCs, unveiling critical species-intrinsic differences in both the identity and activity of these structures.
    Blood 06/2011; 118(7):1774-83. · 9.78 Impact Factor
  • Source
    Sai P Thankamony, Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: According to the multistep model of cell migration, chemokine receptor engagement (step 2) triggers conversion of rolling interactions (step 1) into firm adhesion (step 3), yielding transendothelial migration. We recently reported that glycosyltransferase-programmed stereosubstitution (GPS) of CD44 on human mesenchymal stem cells (hMSCs) creates the E-selectin ligand HCELL (hematopoietic cell E-selectin/L-selectin ligand) and, despite absence of CXCR4, systemically administered HCELL(+)hMSCs display robust osteotropism visualized by intravital microscopy. Here we performed studies to define the molecular effectors of this process. We observed that engagement of hMSC HCELL with E-selectin triggers VLA-4 adhesiveness, resulting in shear-resistant adhesion to ligand VCAM-1. This VLA-4 activation is mediated via a Rac1/Rap1 GTPase signaling pathway, resulting in transendothelial migration on stimulated human umbilical vein endothelial cells without chemokine input. These findings indicate that hMSCs coordinately integrate CD44 ligation and integrin activation, circumventing chemokine-mediated signaling, yielding a step 2-bypass pathway of the canonical multistep paradigm of cell migration.
    Proceedings of the National Academy of Sciences 02/2011; 108(6):2258-63. · 9.81 Impact Factor
  • Source
    Robert Sackstein
    Blood 06/2010; 115(23):4626-7. · 9.78 Impact Factor
  • Source
    Ronald Chester, Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: The breakneck speed of scientific developments in embryonic stem (ES) cell technologies is, commensurately, ushering forth new bioethical debate(s) regarding these cells. A framework of bioethical principles is presented here to guide biomedical scientists and others engaged in improving human welfare through the application of ES cell-based therapies.
    Health matrix 01/2010; 20(1):203-17.
  • Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: The success of stem-cell-based regenerative therapeutics critically hinges on delivering relevant stem/progenitor cells to sites of tissue injury. To achieve adequate parenchymal infiltration following intravascular administration, it is first necessary that circulating cells bind to target tissue endothelium with sufficient strength to overcome the prevailing forces of hemodynamic shear. The principal mediators of these shear-resistant binding interactions consist of a family of C-type lectins known as "selectins" that bind discrete sialofucosylated glycans on their respective ligands. One member of this family, E-selectin, is an endothelial molecule that is inducibly expressed on postcapillary venules at all sites of tissue injury, but is also constitutively expressed on the luminal surface of bone marrow and dermal microvascular endothelium. Most stem/progenitor cells express high levels of CD44, and, in particular, human hematopoietic stem cells express a specialized sialofucosylated glycoform of CD44 known as "hematopoietic cell E-/L-selectin ligand" (HCELL) that functions as a potent E-selectin ligand. This chapter describes a method called "glycosyltransferase-programmed stereosubstitution" (GPS) for custom-modifying CD44 glycans to create HCELL on the surface of living cells that natively lack HCELL. Ex vivo glycan engineering of HCELL via GPS licenses trafficking of infused cells to endothelial beds that express E-selectin, thereby enabling efficient vascular delivery of stem/progenitor cells to sites where they are needed.
    Methods in enzymology 01/2010; 479:93-105. · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A number of glycosyltransferases are present in human plasma with the (13) fucosyltransferase, Fucosyltransferase VI (FTVI), having the highest plasma concentration. Notably, elevated plasma levels of FTVI are associated with a variety of cancers and correlate with tumor load/progression. The well-known association of neoplasia with thromboembolic complications prompted us to examine whether FTVI has direct effect(s) on platelet function. We obtained human platelets from blood of healthy donors and separated from platelet-rich plasma by differential centrifugation. Freshly isolated platelets (x108/ml) were stirred and exposed at 37°C to varying concentrations (20, 40, 60 and 80 mU/mL) of glycosyltransferases FTVI, β-1-4-galactosyltransferase-I (βGalT-I), or ,2-3-N-sialyltransferase (2,3-N-ST), or to 1 U/mL thrombin. Platelet aggregation and activation was assessed by aggregometry (light transmission) or by flow cytometry of FSC/SSC characteristics and of surface expression of P-Selectin, respectively. FT-VI reproducibly induced platelet aggregation and activation, whereas other glycosyltransferases (β4GalT-I and 2,3-N-ST) had no effect on platelets. FTVI activation of platelets was concentration-dependent, and the aggregation curve for FTVI was one wave, similar to that for thrombin. FTVI-induced platelet activation was independent of catalytic conversion of surface glycans, but was inhibited by FTVI denaturation, indicating that FTVI-induced platelet activation is a lectin-mediated process. To determine the membrane target(s) mediating FTVI-induced platelet activation, biochemical studies were performed after catalytic exofucosylation of the platelet surface. Flow cytometry after platelet exofucosylation showed formation of the carbohydrate structure sLex, detected by the mAb Heca452, but no formation of Lex (CD15). Western blot showed that enforced fucosylation induced sLex on a single platelet surface protein, and further biochemical studies revealed that this protein is GPIb. These findings unveil a previously unrecognized property of FTVI as an activator of platelets, mediated via a specific lectin/carbohydrate interaction on GP1ba, and offer novel perspectives on the pathobiology of tumor-associated thrombogenesis.
    Blood 11/2009; 114(22):4016. · 9.78 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The active movement of cells from subendothelial compartments into the bloodstream (intravasation) has been recognized for several decades by histologic and physiologic studies, yet the molecular effectors of this process are relatively uncharacterized. For extravasation, studies based predominantly on static transwell assays support a general model, whereby transendothelial migration (TEM) occurs via chemoattraction toward increasing chemokine concentrations. However, this model of chemotaxis cannot readily reconcile how chemokines influence intravasation, as shear forces of blood flow would likely abrogate luminal chemokine gradient(s). Thus, to analyze how T cells integrate perivascular chemokine signals under physiologic flow, we developed a novel transwell-based flow chamber allowing for real-time modulation of chemokine levels above (luminal/apical compartment) and below (abluminal/subendothelial compartment) HUVEC monolayers. We routinely observed human T cell TEM across HUVEC monolayers with the combination of luminal CXCL12 and abluminal CCL5. With increasing concentrations of CXCL12 in the luminal compartment, transmigrated T cells did not undergo retrograde transendothelial migration (retro-TEM). However, when exposedto abluminal CXCL12, transmigrated T cells underwent striking retro-TEM and re-entered the flow stream [corrected]. This CXCL12 fugetactic (chemorepellant) effect was concentration-dependent, augmented by apical flow, blocked by antibodies to integrins, and reduced by AMD3100 in a dose-dependent manner. Moreover, CXCL12-induced retro-TEM was inhibited by PI3K antagonism and cAMP agonism. These findings broaden our understanding of chemokine biology and support a novel paradigm by which temporospatial modulations in subendothelial chemokine display drive cell migration from interstitial compartments into the bloodstream.
    Journal of leukocyte biology 10/2009; 86(6):1285-94. · 4.99 Impact Factor
  • Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: During evolution of the vertebrate cardiovascular system, the vast endothelial surface area associated with branching vascular networks mandated the development of molecular processes to efficiently and specifically recruit circulating sentinel host defense cells and tissue repair cells at localized sites of inflammation/tissue injury. The forces engendered by high-velocity blood flow commensurately required the evolution of specialized cell surface molecules capable of mediating shear-resistant endothelial adhesive interactions, thus literally capturing relevant cells from the blood stream onto the target endothelial surface and permitting subsequent extravasation. The principal effectors of these shear-resistant binding interactions comprise a family of C-type lectins known as 'selectins' that bind discrete sialofucosylated glycans on their respective ligands. This review explains the 'intelligent design' of requisite reagents to convert native CD44 into the sialofucosylated glycoform known as hematopoietic cell E-/L-selectin ligand (HCELL), the most potent E-selectin counter-receptor expressed on human cells, and will describe how ex vivo glycan engineering of HCELL expression may open the 'avenues' for the efficient vascular delivery of cells for a variety of cell therapies.
    Immunological Reviews 08/2009; 230(1):51-74. · 12.16 Impact Factor
  • Robert Sackstein, Robert Fuhlbrigge
    [Show abstract] [Hide abstract]
    ABSTRACT: Western blotting has proven to be an important technique in analysis of receptor-ligand interactions (i.e., by ligand blotting) and for identifying molecules mediating cell attachment (i.e., by cell blotting). Conventional ligand blotting and cell blotting methods employ nondynamic (static) incubation conditions, whereby molecules or cells of interest are placed in suspension and overlaid on membranes. However, many cell-cell and cell-matrix adhesive interactions occur under fluid shear conditions, and shear stress itself mediates and/or facilitates the engagement of these physiologically appropriate receptors and ligands. Notably, shear forces critically influence the adhesion of circulating cells and platelets to vessel walls in physiologic cell migration and hemostasis, as well as in inflammatory and thrombotic disorders, cancer metastasis, and atherosclerosis. Use of nondynamic blotting conditions to analyze such interactions can introduce bias, overtly missing relevant effectors and/or exaggerating the relative role(s) of nonphysiologic adhesion molecules. To address this shortfall, we have developed a new technique for identifying binding interactions under fluid shear conditions, the "blot rolling assay." Using this method, molecules in a complex mixture are resolved by gel electrophoresis, transferred to a membrane that is rendered semi-transparent, and the membrane is then incorporated into a parallel-plate flow chamber apparatus. Under controlled flow conditions, cells or particles bearing adhesion proteins of interest are then introduced into the chamber and interactions with individual immobilized molecules (bands) can be visualized in real-time. The substrate molecule(s) supporting adhesion under fluid shear can then be identified by staining with specific antibodies or by excising the relevant band(s) and performing mass spectrometry or microsequencing of the isolated material. This method thus allows for the identification, within a complex mixture and without prior isolation or purification, of both known and previously uncharacterized adhesion molecules operational under dynamic conditions.
    Methods in molecular biology (Clifton, N.J.) 02/2009; 536:343-54. · 1.29 Impact Factor
  • Source
    Samah Zeineb Gadhoum, Robert Sackstein
    [Show abstract] [Hide abstract]
    ABSTRACT: The glycan determinant CD15 (also known as Lewis x, or Le(x)) is a distinguishing marker for human myeloid cells and mediates neutrophil adhesion to dendritic cells. Despite broad interest in this structure, the mechanisms underlying CD15 expression remain relatively uncharacterized. Accordingly, we investigated the molecular basis of increasing CD15 expression associated with human myeloid cell differentiation. Flow cytometric analysis of differentiating cells together with biochemical studies using inhibitors of glycan synthesis and of sialidases showed that increased CD15 expression is not due to de novo biosynthesis of CD15, but results predominantly from induction of alpha(2-3)-sialidase activity, which yields CD15 from cell-surface sialyl-CD15 (also known as sialyl-Lewis x, sLe(x) or CD15s). This differentiation-associated conversion of surface CD15s to CD15 occurs mainly on glycoproteins. Until now, modulation of post-translational glycan modifications has been attributed solely to dynamic variations in glycosyltransferase expression. Our results unveil a new paradigm by demonstrating a critical role for post-Golgi membrane glycosidase activity in the 'biosynthesis' of a key glycan determinant.
    Nature Chemical Biology 11/2008; 4(12):751-7. · 12.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Waldenstrom macroglobulinemia (WM) is characterized by widespread involvement of the bone marrow at the time of diagnosis, implying continuous homing of WM cells into the marrow. The mechanisms by which trafficking of the malignant cells into the bone marrow has not been previously elucidated. In this study, we show that WM cells express high levels of chemokine and adhesion receptors, including CXCR4 and VLA-4. We showed that CXCR4 was essential for the migration and trans-endothelial migration of WM cells under static and dynamic shear flow conditions, with significant inhibition of migration using CXCR4 knockdown or the CXCR4 inhibitor AMD3100. Similarly, CXCR4 or VLA-4 inhibition led to significant inhibition of adhesion to fibronectin, stromal cells, and endothelial cells. Decreased adhesion of WM cells to stromal cells by AMD3100 led to increased sensitivity of these cells to cytotoxicity by bortezomib. To further investigate the mechanisms of CXCR4-dependent adhesion, we showed that CXCR4 and VLA-4 directly interact in response to SDF-1, we further investigated downstream signaling pathways regulating migration and adhesion in WM. Together, these studies demonstrate that the CXCR4/SDF-1 axis interacts with VLA-4 in regulating migration and adhesion of WM cells in the bone marrow microenvironment.
    Blood 08/2008; 112(1):150-8. · 9.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cell migration in blood flow is mediated by engagement of specialized adhesion molecules that function under hemodynamic shear conditions, and many of the effectors of these adhesive interactions, such as the selectins and their ligands, are well defined. However, in contrast, our knowledge of the adhesion molecules operant under lymphatic flow conditions is incomplete. Among human malignancies, head and neck squamous cell cancer displays a marked predilection for locoregional lymph node metastasis. Based on this distinct tropism, we hypothesized that these cells express adhesion molecules that promote their binding to lymphoid tissue under lymphatic fluid shear stress. Accordingly, we investigated adhesive interactions between these and other cancer cells and the principal resident cells of lymphoid organs, lymphocytes. Parallel plate flow chamber studies under defined shear conditions, together with biochemical analyses, showed that human head and neck squamous cell cancer cells express heretofore unrecognized L-selectin ligand(s) that mediate binding to lymphocyte L-selectin at conspicuously low shear stress levels of 0.07-0.08 dynes/cm(2), consistent with lymphatic flow. The binding of head and neck squamous cancer cells to L-selectin displays canonical biochemical features, such as requirements for sialylation, sulfation, and N-glycosylation, but displays a novel operational shear threshold differing from all other L-selectin ligands, including those expressed on colon cancer and leukemic cells (e.g. HCELL). These data define a novel class of L-selectin ligands and expand the scope of function for L-selectin within circulatory systems to now include a novel activity within shear stresses characteristic of lymphatic flow.
    Journal of Biological Chemistry 07/2008; 283(23):15816-24. · 4.65 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The capacity to direct migration ('homing') of blood-borne cells to a predetermined anatomic compartment is vital to stem cell-based tissue engineering and other adoptive cellular therapies. Although multipotent mesenchymal stromal cells (MSCs, also termed 'mesenchymal stem cells') hold the potential for curing generalized skeletal diseases, their clinical effectiveness is constrained by the poor osteotropism of infused MSCs (refs. 1-3). Cellular recruitment to bone occurs within specialized marrow vessels that constitutively express vascular E-selectin, a lectin that recognizes sialofucosylated determinants on its various ligands. We show here that human MSCs do not express E-selectin ligands, but express a CD44 glycoform bearing alpha-2,3-sialyl modifications. Using an alpha-1,3-fucosyltransferase preparation and enzymatic conditions specifically designed for treating live cells, we converted the native CD44 glycoform on MSCs into hematopoietic cell E-selectin/L-selectin ligand (HCELL), which conferred potent E-selectin binding without effects on cell viability or multipotency. Real-time intravital microscopy in immunocompromised (NOD/SCID) mice showed that intravenously infused HCELL(+) MSCs infiltrated marrow within hours of infusion, with ensuing rare foci of endosteally localized cells and human osteoid generation. These findings establish that the HCELL glycoform of CD44 confers tropism to bone and unveil a readily translatable roadmap for programming cellular trafficking by chemical engineering of glycans on a distinct membrane glycoprotein.
    Nature medicine 03/2008; 14(2):181-7. · 27.14 Impact Factor

Publication Stats

3k Citations
573.31 Total Impact Points

Institutions

  • 2006–2012
    • Dana-Farber Cancer Institute
      • Department of Medical Oncology
      Boston, Massachusetts, United States
  • 2001–2012
    • Brigham and Women's Hospital
      • • Department of Dermatology
      • • Center for Brain Mind Medicine
      • • Department of Medicine
      Boston, MA, United States
  • 2010
    • New England School of Law
      Arkansas, United States
  • 1984–2010
    • Harvard Medical School
      • Department of Pediatrics
      Boston, Massachusetts, United States
  • 2008
    • University of Texas Medical Branch at Galveston
      Galveston, Texas, United States
  • 2005
    • Johns Hopkins University
      • Department of Chemical and Biomolecular Engineering
      Baltimore, MD, United States
  • 2004
    • Roger Williams University
      Bristol, Rhode Island, United States
  • 1996–2004
    • University of South Florida
      Tampa, Florida, United States
  • 2003
    • University of Toronto
      Toronto, Ontario, Canada
  • 1999–2003
    • Massachusetts General Hospital
      • • Department of Surgery
      • • Transplantation Biology Research Center
      Boston, MA, United States
  • 1993–1997
    • Moffitt Cancer Center
      Tampa, Florida, United States
  • 1988–1989
    • University of Miami Miller School of Medicine
      • Department of Microbiology and Immunology
      Miami, FL, United States
    • University of Miami
      • Department of Medicine
      كورال غيبلز، فلوريدا, Florida, United States