1
|
Irons EE, Sajina GC, Lau JT. Sialic acid in the regulation of blood cell production, differentiation and turnover. Immunology 2024; 172:517-532. [PMID: 38503445 PMCID: PMC11223974 DOI: 10.1111/imm.13780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 03/04/2024] [Indexed: 03/21/2024] Open
Abstract
Sialic acid is a unique sugar moiety that resides in the distal and most accessible position of the glycans on mammalian cell surface and extracellular glycoproteins and glycolipids. The potential for sialic acid to obscure underlying structures has long been postulated, but the means by which such structural changes directly affect biological processes continues to be elucidated. Here, we appraise the growing body of literature detailing the importance of sialic acid for the generation, differentiation, function and death of haematopoietic cells. We conclude that sialylation is a critical post-translational modification utilized in haematopoiesis to meet the dynamic needs of the organism by enforcing rapid changes in availability of lineage-specific cell types. Though long thought to be generated only cell-autonomously within the intracellular ER-Golgi secretory apparatus, emerging data also demonstrate previously unexpected diversity in the mechanisms of sialylation. Emphasis is afforded to the mechanism of extrinsic sialylation, whereby extracellular enzymes remodel cell surface and extracellular glycans, supported by charged sugar donor molecules from activated platelets.
Collapse
Affiliation(s)
| | | | - Joseph T.Y. Lau
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14203 USA
| |
Collapse
|
2
|
Punch PR, Irons EE, Manhardt CT, Marathe H, Lau JTY. The sialyltransferase ST6GAL1 protects against radiation-induced gastrointestinal damage. Glycobiology 2021; 30:446-453. [PMID: 31897489 DOI: 10.1093/glycob/cwz108] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 12/14/2022] Open
Abstract
High-dose irradiation poses extreme risk of mortality from acute damage to the hematopoietic compartment and gastrointestinal tract. While bone marrow transplantation can reestablish the hematopoietic compartment, a more imminent risk of death is posed by gastrointestinal acute radiation syndrome (GI-ARS), for which there are no FDA-approved medical countermeasures. Although the mechanisms dictating the severity of GI-ARS remain incompletely understood, sialylation by ST6GAL1 has been shown to protect against radiation-induced apoptosis in vitro. Here, we used a C57BL/6 St6gal1-KO mouse model to investigate the contribution of ST6GAL1 to susceptibility to total body irradiation in vivo. Twelve gray total body ionizing γ-irradiation (TBI) followed by bone marrow transplant is not lethal to wild-type mice, but St6gal1-KO counterparts succumbed within 7 d. Both St6gal1-KO and wild-type animals exhibited damage to the GI epithelium, diarrhea and weight loss, but these symptoms became progressively more severe in the St6gal1-KO animals while wild-type counterparts showed signs of recovery by 120 h after TBI. Increased apoptosis in the GI tracts of St6gal1-KO mice and the absence of regenerative crypts were also observed. Together, these observations highlight an important role for ST6GAL1 in protection and recovery from GI-ARS in vivo.
Collapse
Affiliation(s)
- Patrick R Punch
- Department of Molecular & Cellular Biology, Roswell Park Comprehensive Cancer Center, Elm & Carlton Streets, Buffalo, NY 14263, USA
| | - Eric E Irons
- Department of Molecular & Cellular Biology, Roswell Park Comprehensive Cancer Center, Elm & Carlton Streets, Buffalo, NY 14263, USA
| | - Charles T Manhardt
- Department of Molecular & Cellular Biology, Roswell Park Comprehensive Cancer Center, Elm & Carlton Streets, Buffalo, NY 14263, USA
| | - Himangi Marathe
- Department of Molecular & Cellular Biology, Roswell Park Comprehensive Cancer Center, Elm & Carlton Streets, Buffalo, NY 14263, USA
| | - Joseph T Y Lau
- Department of Molecular & Cellular Biology, Roswell Park Comprehensive Cancer Center, Elm & Carlton Streets, Buffalo, NY 14263, USA
| |
Collapse
|
3
|
Irons EE, Lee-Sundlov MM, Zhu Y, Neelamegham S, Hoffmeister KM, Lau JT. B cells suppress medullary granulopoiesis by an extracellular glycosylation-dependent mechanism. eLife 2019; 8:47328. [PMID: 31408003 PMCID: PMC6713473 DOI: 10.7554/elife.47328] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 08/10/2019] [Indexed: 12/18/2022] Open
Abstract
The immune response relies on the integration of cell-intrinsic processes with cell-extrinsic cues. During infection, B cells vacate the marrow during emergency granulopoiesis but return upon restoration of homeostasis. Here we report a novel glycosylation-mediated crosstalk between marrow B cells and hematopoietic progenitors. Human B cells secrete active ST6GAL1 sialyltransferase that remodels progenitor cell surface glycans to suppress granulopoiesis. In mouse models, ST6GAL1 from B cells alters the sialylation profile of bone marrow populations, and mature IgD+ B cells were enriched in sialylated bone marrow niches. In clinical multiple myeloma, ST6GAL1 abundance in the multiple myeloma cells negatively correlated with neutrophil abundance. These observations highlight not only the ability of medullary B cells to influence blood cell production, but also the disruption to normal granulopoiesis by excessive ST6GAL1 in malignancy.
Collapse
Affiliation(s)
- Eric E Irons
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, United States
| | | | - Yuqi Zhu
- Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, United States
| | - Sriram Neelamegham
- Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, United States
| | | | - Joseph Ty Lau
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, United States
| |
Collapse
|
4
|
Nasirikenari M, Lugade AA, Neelamegham S, Gao Z, Moremen KW, Bogner PN, Thanavala Y, Lau JTY. Recombinant Sialyltransferase Infusion Mitigates Infection-Driven Acute Lung Inflammation. Front Immunol 2019; 10:48. [PMID: 30778346 PMCID: PMC6369197 DOI: 10.3389/fimmu.2019.00048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/09/2019] [Indexed: 11/13/2022] Open
Abstract
Inappropriate inflammation exacerbates a vast array of chronic and acute conditions with severe health risks. In certain situations, such as acute sepsis, traditional therapies may be inadequate in preventing severe organ damage or death. We have previously shown cell surface glycan modification by the circulating sialyltransferase ST6Gal-1 regulates de novo inflammatory cell production via a novel extrinsic glycosylation pathway. Here, we show that therapeutic administration of recombinant, bioactive ST6Gal-1 (rST6G) mitigates acute inflammation in a murine model mimicking acute exacerbations experienced by patients with chronic obstructive pulmonary disease (COPD). In addition to suppressing proximal neutrophil recruitment at onset of infection-mediated inflammation, rST6G also muted local cytokine production. Histologically, exposure with NTHI, a bacterium associated with COPD exacerbations, in rST6G-treated animals revealed consistent and pronounced reduction of pulmonary inflammation, characterized by smaller inflammatory cuffs around bronchovascular bundles, and fewer inflammatory cells within alveolar walls, alveolar spaces, and on pleural surfaces. Taken together, the data advance the idea that manipulating circulatory ST6Gal-1 levels has potential in managing inflammatory conditions by leveraging the combined approaches of controlling new inflammatory cell production and dampening the inflammation mediator cascade.
Collapse
Affiliation(s)
- Mehrab Nasirikenari
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Amit A Lugade
- Department of Immunology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Sriram Neelamegham
- Department of Chemical and Biomedical Engineering, University at Buffalo, Buffalo, NY, United States
| | - Zhongwei Gao
- The Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Kelley W Moremen
- The Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Paul N Bogner
- Department of Pathology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Yasmin Thanavala
- Department of Immunology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Joseph T Y Lau
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| |
Collapse
|
5
|
Irons EE, Lau JTY. Systemic ST6Gal-1 Is a Pro-survival Factor for Murine Transitional B Cells. Front Immunol 2018; 9:2150. [PMID: 30294329 PMCID: PMC6159744 DOI: 10.3389/fimmu.2018.02150] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 08/31/2018] [Indexed: 11/13/2022] Open
Abstract
Humoral immunity depends on intrinsic B cell developmental programs guided by systemic signals that convey physiologic needs. Aberrant cues or their improper interpretation can lead to immune insufficiency or a failure of tolerance and autoimmunity. The means by which such systemic signals are conveyed remain poorly understood. Hence, further insight is essential to understanding and treating autoimmune diseases and to the development of improved vaccines. ST6Gal-1 is a sialyltransferase that constructs the α2,6-sialyl linkage on cell surface and extracellular glycans. The requirement for functional ST6Gal-1 in the development of humoral immunity is well documented. Canonically, ST6Gal-1 resides within the intracellular ER-Golgi secretory apparatus and participates in cell-autonomous glycosylation. However, a significant pool of extracellular ST6Gal-1 exists in circulation. Here, we segregate the contributions of B cell intrinsic and extrinsic ST6Gal-1 to B cell development. We observed that B cell-intrinsic ST6Gal-1 is required for marginal zone B cell development, while B cell non-autonomous ST6Gal-1 modulates B cell development and survival at the early transitional stages of the marrow and spleen. Exposure to extracellular ST6Gal-1 ex vivo enhanced the formation of IgM-high B cells from immature precursors, and increased CD23 and IgM expression. Extrinsic sialylation by extracellular ST6Gal-1 augmented BAFF-mediated activation of the non-canonical NF-kB, p38 MAPK, and PI3K/AKT pathways, and accelerated tyrosine phosphorylation after B cell receptor stimulation. in vivo, systemic ST6Gal-1 did not influence homing of B cells to the spleen but was critical for their long-term survival and systemic IgG levels. Circulatory ST6Gal-1 levels respond to inflammation, infection, and malignancy in mammals, including humans. In turn, we have shown previously that systemic ST6Gal-1 regulates inflammatory cell production by modifying bone marrow myeloid progenitors. Our data here point to an additional role of systemic ST6Gal-1 in guiding B cell development, which supports the concept that circulating ST6Gal-1 is a conveyor of systemic cues to guide the development of multiple branches of immune cells.
Collapse
Affiliation(s)
- Eric E Irons
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| | - Joseph T Y Lau
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States
| |
Collapse
|
6
|
Dougher CWL, Buffone A, Nemeth MJ, Nasirikenari M, Irons EE, Bogner PN, Lau JTY. The blood-borne sialyltransferase ST6Gal-1 is a negative systemic regulator of granulopoiesis. J Leukoc Biol 2017; 102:507-516. [PMID: 28550122 PMCID: PMC5505748 DOI: 10.1189/jlb.3a1216-538rr] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/26/2017] [Accepted: 04/27/2017] [Indexed: 12/25/2022] Open
Abstract
Responding to systemic demands in producing and replenishing end-effector blood cells is predicated on the appropriate delivery and interpretation of extrinsic signals to the HSPCs. The data presented herein implicate the systemic, extracellular form of the glycosyltransferase ST6Gal-1 in the regulation of late-stage neutrophil development. ST6Gal-1 is typically a membrane-bound enzyme sequestered within the intracellular secretory apparatus, but an extracellular form is released into the blood from the liver. Both human and murine HSPCs, upon exposure to extracellular ST6Gal-1 ex vivo, exhibited decreased proliferation, diminished expression of the neutrophilic primary granule protein MPO, and decreased appearance of CD11b+ cells. HSPC suppression was preceded by decreased STAT-3 phosphorylation and diminished C/EBPα expression, without increased apoptosis, indicating attenuated G-CSF receptor signaling. A murine model to raise systemic ST6Gal-1 level was developed to examine the role of the circulatory enzyme in vivo. Our results show that systemic ST6Gal-1 modified the cell surface of the GMP subset of HSPCs and decreased marrow neutrophil reserves. Acute airway neutrophilic inflammation by LPS challenge was used to drive demand for new neutrophil production. Reduced neutrophil infiltration into the airway was observed in mice with elevated circulatory ST6Gal-1 levels. The blunted transition of GMPs into GPs in vitro is consistent with ST6Gal-1-attenuated granulopoiesis. The data confirm that circulatory ST6Gal-1 is a negative systemic regulator of granulopoiesis and moreover suggest a clinical potential to limit the number of inflammatory cells by manipulating blood ST6Gal-1 levels.
Collapse
Affiliation(s)
| | - Alexander Buffone
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
| | - Michael J Nemeth
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New York, USA
| | - Mehrab Nasirikenari
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
| | - Eric E Irons
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
| | - Paul N Bogner
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, New York, USA
| | - Joseph T Y Lau
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
| |
Collapse
|
7
|
Manhardt CT, Punch PR, Dougher CWL, Lau JTY. Extrinsic sialylation is dynamically regulated by systemic triggers in vivo. J Biol Chem 2017; 292:13514-13520. [PMID: 28717006 DOI: 10.1074/jbc.c117.795138] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/12/2017] [Indexed: 12/19/2022] Open
Abstract
Recent reports have documented that extracellular sialyltransferases can remodel both cell-surface and secreted glycans by a process other than the canonical cell-autonomous glycosylation that occurs within the intracellular secretory apparatus. Despite association of the abundance of these extracellular sialyltransferases, particularly ST6Gal-1, with disease states such as cancer and a variety of inflammatory conditions, the prevalence of this extrinsic glycosylation pathway in vivo remains unknown. Here we observed no significant extrinsic sialylation in resting mice, suggesting that extrinsic sialylation is not a constitutive process. However, extrinsic sialylation in the periphery could be triggered by inflammatory challenges, such as exposure to ionizing radiation or to bacterial lipopolysaccharides. Sialic acids from circulating platelets were used in vivo to remodel target cell surfaces. Platelet activation was minimally sufficient to elicit extrinsic sialylation, as demonstrated with the FeCl3 model of mesenteric artery thrombosis. Although extracellular ST6Gal-1 supports extrinsic sialylation, other sialyltransferases are present in systemic circulation. We also observed in vivo extrinsic sialylation in animals deficient in ST6Gal-1, demonstrating that extrinsic sialylation is not mediated exclusively by ST6Gal-1. Together, these observations form an emerging picture of glycans biosynthesized by the canonical cell-autonomous glycosylation pathway, but subjected to remodeling by extracellular glycan-modifying enzymes.
Collapse
Affiliation(s)
| | | | | | - Joseph T Y Lau
- From the Departments of Molecular and Cellular Biology and
| |
Collapse
|
8
|
Treister NS, Richards SM, Lombardi MJ, Rowley P, Jensen RV, Sullivan DA. Sex-related Differences in Gene Expression in Salivary Glands of BALB/c Mice. J Dent Res 2016; 84:160-5. [PMID: 15668334 DOI: 10.1177/154405910508400210] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Sex-related differences exist in the structure and function of the major glands in a variety of species. Moreover, many of these variations appear to be unique to each tissue. We hypothesized that this sexual dimorphism is due, at least in part, to gland-specific differences in gene expression between males and females. Glands were collected from male and female BALB/c mice (n = 5/sex/experiment), and total RNA was isolated. Samples were analyzed for differentially expressed mRNAs with CodeLink microarrays, and data were evaluated by GeneSifter. Our results demonstrate that significant (P < 0.05) sex-related differences exist in the expression of numerous genes in the major salivary glands, and many of these differences were tissue-specific. These findings support our hypothesis that sex-related differences in the salivary glands are due, at least in part, to tissue-specific variations in gene expression.
Collapse
Affiliation(s)
- N S Treister
- Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA 02114, USA.
| | | | | | | | | | | |
Collapse
|
9
|
Monticelli M, Ferro T, Jaeken J, Dos Reis Ferreira V, Videira PA. Immunological aspects of congenital disorders of glycosylation (CDG): a review. J Inherit Metab Dis 2016; 39:765-780. [PMID: 27393411 DOI: 10.1007/s10545-016-9954-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/16/2016] [Accepted: 06/06/2016] [Indexed: 02/06/2023]
Abstract
Congenital disorders of glycosylation (CDG) are a rapidly growing family of genetic diseases comprising more than 85 known distinct disorders. They show a great phenotypic variability ranging from multi-organ/system to mono-organ/system involvement with very mild to extremely severe expression. Immunological dysfunction has a significant impact on the phenotype in a minority of CDG. CDG with major immunological involvement are ALG12-CDG, MAGT1-CDG, MOGS-CDG, SLC35C1-CDG and PGM3-CDG. This review discusses the variety of immunological abnormalities reported in human CDG. Understanding the immunological aspects of CDG may contribute to a better management/treatment of these pathologies and possibly of more common diseases, such as inflammatory diseases.
Collapse
Affiliation(s)
- Maria Monticelli
- Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
- Dipartimento di Biologia, Università degli Studi di Napoli "Federico II", Naples, Italy
| | - Tiago Ferro
- Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Jaak Jaeken
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal
- Center for Metabolic Disease, KU Leuven, Leuven, Belgium
| | - Vanessa Dos Reis Ferreira
- Portuguese Association for Congenital Disorders of Glycosylation (CDG), Lisbon, Portugal.
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal.
| | - Paula A Videira
- Centro de Estudos de Doenças Crónicas, CEDOC, NOVA Medical School / Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisbon, Portugal.
- UCIBIO, Departamento Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal.
- CDG & Allies - Professionals and Patient Associations International Network (CDG & Allies - PPAIN), Caparica, Portugal.
| |
Collapse
|
10
|
Lee-Sundlov MM, Ashline DJ, Hanneman AJ, Grozovsky R, Reinhold VN, Hoffmeister KM, Lau JT. Circulating blood and platelets supply glycosyltransferases that enable extrinsic extracellular glycosylation. Glycobiology 2016; 27:188-198. [PMID: 27798070 DOI: 10.1093/glycob/cww108] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/30/2016] [Accepted: 10/21/2016] [Indexed: 01/03/2023] Open
Abstract
Glycosyltransferases, usually residing within the intracellular secretory apparatus, also circulate in the blood. Many of these blood-borne glycosyltransferases are associated with pathological states, including malignancies and inflammatory conditions. Despite the potential for dynamic modifications of glycans on distal cell surfaces and in the extracellular milieu, the glycan-modifying activities present in systemic circulation have not been systematically examined. Here, we describe an evaluation of blood-borne sialyl-, galactosyl- and fucosyltransferase activities that act upon the four common terminal glycan precursor motifs, GlcNAc monomer, Gal(β3)GlcNAc, Gal(β4)GlcNAc and Gal(β3)GalNAc, to produce more complex glycan structures. Data from radioisotope assays and detailed product analysis by sequential tandem mass spectrometry show that blood has the capacity to generate many of the well-recognized and important glycan motifs, including the Lewis, sialyl-Lewis, H- and Sialyl-T antigens. While many of these glycosyltransferases are freely circulating in the plasma, human and mouse platelets are important carriers for others, including ST3Gal-1 and β4GalT. Platelets compartmentalize glycosyltransferases and release them upon activation. Human platelets are also carriers for large amounts of ST6Gal-1 and the α3-sialyl to Gal(β4)GlcNAc sialyltransferases, both of which are conspicuously absent in mouse platelets. This study highlights the capability of circulatory glycosyltransferases, which are dynamically controlled by platelet activation, to remodel cell surface glycans and alter cell behavior.
Collapse
Affiliation(s)
- Melissa M Lee-Sundlov
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - David J Ashline
- The Glycomics Center, Division of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Andrew J Hanneman
- The Glycomics Center, Division of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Renata Grozovsky
- Division of Hematology, Brigham and Women's Hospital and Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Vernon N Reinhold
- The Glycomics Center, Division of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Karin M Hoffmeister
- Division of Hematology, Brigham and Women's Hospital and Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Joseph Ty Lau
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| |
Collapse
|
11
|
Srivastava S, Makarava N, Katorcha E, Savtchenko R, Brossmer R, Baskakov IV. Post-conversion sialylation of prions in lymphoid tissues. Proc Natl Acad Sci U S A 2015; 112:E6654-62. [PMID: 26627256 PMCID: PMC4672809 DOI: 10.1073/pnas.1517993112] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sialylated glycans on the surface of mammalian cells act as part of a "self-associated molecular pattern," helping the immune system to recognize "self" from "altered self" or "nonself." To escape the host immune system, some bacterial pathogens have evolved biosynthetic pathways for host-like sialic acids, whereas others recruited host sialic acids for decorating their surfaces. Prions lack nucleic acids and are not conventional pathogens. Nevertheless, prions might use a similar strategy for invading and colonizing the lymphoreticular system. Here we show that the sialylation status of the infectious, disease-associated state of the prion protein (PrP(Sc)) changes with colonization of secondary lymphoid organs (SLOs). As a result, spleen-derived PrP(Sc) is more sialylated than brain-derived PrP(Sc). Enhanced sialylation of PrP(Sc) is recapitulated in vitro by incubating brain-derived PrP(Sc) with primary splenocytes or cultured macrophage RAW 264.7 cells. General inhibitors of sialyltranserases (STs), the enzymes that transfer sialic acid residues onto terminal positions of glycans, suppressed extrasialylation of PrP(Sc). A fluorescently labeled precursor of sialic acid revealed ST activity associated with RAW macrophages. This study illustrates that, upon colonization of SLOs, the sialylation status of prions changes by host STs. We propose that this mechanism is responsible for camouflaging prions in SLOs and has broad implications.
Collapse
Affiliation(s)
- Saurabh Srivastava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Natallia Makarava
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Elizaveta Katorcha
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Regina Savtchenko
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201
| | - Reinhard Brossmer
- Biochemistry Center, University of Heidelberg, 69120 Heidelberg, Germany
| | - Ilia V Baskakov
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201;
| |
Collapse
|
12
|
Crespo HJ, Lau JTY, Videira PA. Dendritic cells: a spot on sialic Acid. Front Immunol 2013; 4:491. [PMID: 24409183 PMCID: PMC3873530 DOI: 10.3389/fimmu.2013.00491] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 12/15/2013] [Indexed: 11/17/2022] Open
Abstract
Glycans decorating cell surface and secreted proteins and lipids occupy the juncture where critical host–host and host-pathogen interactions occur. The role of glycan epitopes in cell–cell and cell-pathogen adhesive events is already well-established, and cell surface glycan structures change rapidly in response to stimulus and inflammatory cues. Despite the wide acceptance that glycans are centrally implicated in immunity, exactly how glycans and their changes contribute to the overall immune response remains poorly defined. Sialic acids are unique sugars that usually occupy the terminal position of the glycan chains and may be modified by external factors, such as pathogens, or upon specific physiological cellular events. At cell surface, sialic acid-modified structures form the key fundamental determinants for a number of receptors with known involvement in cellular adhesiveness and cell trafficking, such as the Selectins and the Siglec families of carbohydrate recognizing receptors. Dendritic cells (DCs) preside over the transition from innate to the adaptive immune repertoires, and no other cell has such relevant role in antigen screening, uptake, and its presentation to lymphocytes, ultimately triggering the adaptive immune response. Interestingly, sialic acid-modified structures are involved in all DC functions, such as antigen uptake, DC migration, and capacity to prime T cell responses. Sialic acid content changes along DC differentiation and activation and, while, not yet fully understood, these changes have important implications in DC functions. This review focuses on the developmental regulation of DC surface sialic acids and how manipulation of DC surface sialic acids can affect immune-critical DC functions by altering antigen endocytosis, pathogen and tumor cell recognition, cell recruitment, and capacity for T cell priming. The existing evidence points to a potential of DC surface sialylation as a therapeutic target to improve and diversify DC-based therapies.
Collapse
Affiliation(s)
- Hélio J Crespo
- CEDOC - UC Imunologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa , Lisbon , Portugal ; Department of Molecular and Cellular Biology, Roswell Park Cancer Institute , Buffalo, NY , USA
| | - Joseph T Y Lau
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute , Buffalo, NY , USA
| | - Paula A Videira
- CEDOC - UC Imunologia, Faculdade de Ciências Médicas, Universidade Nova de Lisboa , Lisbon , Portugal
| |
Collapse
|
13
|
Petit D, Mir AM, Petit JM, Thisse C, Delannoy P, Oriol R, Thisse B, Harduin-Lepers A. Molecular phylogeny and functional genomics of beta-galactoside alpha2,6-sialyltransferases that explain ubiquitous expression of st6gal1 gene in amniotes. J Biol Chem 2010; 285:38399-414. [PMID: 20855889 DOI: 10.1074/jbc.m110.163931] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Sialyltransferases are key enzymes in the biosynthesis of sialoglycoconjugates that catalyze the transfer of sialic residue from its activated form to an oligosaccharidic acceptor. β-Galactoside α2,6-sialyltransferases ST6Gal I and ST6Gal II are the two unique members of the ST6Gal family described in higher vertebrates. The availability of genome sequences enabled the identification of more distantly related invertebrates' st6gal gene sequences and allowed us to propose a scenario of their evolution. Using a phylogenomic approach, we present further evidence of an accelerated evolution of the st6gal1 genes both in their genomic regulatory sequences and in their coding sequence in reptiles, birds, and mammals known as amniotes, whereas st6gal2 genes conserve an ancestral profile of expression throughout vertebrate evolution.
Collapse
Affiliation(s)
- Daniel Petit
- Unité de Génétique Moléculaire Animale, Université de Limoges Faculté des Sciences et Techniques, INRA UMR 1061, 123 Avenue Albert Thomas, 87060 Limoges, France
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Cabral MG, Piteira AR, Silva Z, Ligeiro D, Brossmer R, Videira PA. Human dendritic cells contain cell surface sialyltransferase activity. Immunol Lett 2010; 131:89-96. [PMID: 20206207 DOI: 10.1016/j.imlet.2010.02.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 02/22/2010] [Accepted: 02/24/2010] [Indexed: 11/17/2022]
Abstract
Human monocyte-derived dendritic cells (mo-DCs) express highly sialylated structures, with recognized but poorly understood function in maturation, immunogenicity and endocytosis capacity. We have previously shown that mo-DCs surface sialylation is changeable upon different stimuli, which led us to hypothesise the existence of cell surface (non-intracellular) sialyltransferases, rapidly restoring or altering mo-DC surface sialylation, thus modulating specific functions. Here, we demonstrate that, in the presence of exogenous CMP-Neu5Ac, mo-DCs incorporate considerable amounts of sialic acids into cell surface, predominantly when mo-DCs were previously desialylated or matured. This is a genuine sialyltransferase activity, confirmed by specific inhibition assays, which is not influenced by secreted enzymes. Functionally, the ecto-sialyltransferase activity causes a significant down-regulation of mo-DCs endocytic capacity, without affecting the maturation state. These findings suggest that ecto-sialyltransferases participate in a dynamic control of mo-DC sialylation, with functional repercussions. This activity is possibly related with specific physiological and pathological conditions, as inflammation and infection, contributing to protection and homeostasis regulation.
Collapse
Affiliation(s)
- M Guadalupe Cabral
- CEDOC, Departamento de Imunologia, Faculdade de Ciências Médicas, FCM, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, Lisbon, Portugal
| | | | | | | | | | | |
Collapse
|
15
|
Laporte B, Gonzalez-Hilarion S, Maftah A, Petit JM. The second bovine beta-galactoside-alpha2,6-sialyltransferase (ST6Gal II): genomic organization and stimulation of its in vitro expression by IL-6 in bovine mammary epithelial cells. Glycobiology 2009; 19:1082-93. [PMID: 19617256 DOI: 10.1093/glycob/cwp094] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have cloned a cDNA sequence encoding the second bovine beta-galactoside-alpha2,6-sialyltransferase whose sequence shares more than 75% of identity with hST6Gal II cDNA coding sequence. The bovine gene, located on BTA 11, spans over 50 kbp with five exons (E1-E5) containing the 1488 bp open reading frame and a 5'-untranslated exon (E0). The gene expression pattern reveals a specific tissue distribution (brain, lungs, spleen, salivary, and mammary glands) compared to ST6Gal I which is ubiquitously expressed. We identified for bovine ST6Gal II three kinds of transcripts which differ by their 5'-untranslated regions. Among them, two transcripts are brain specific whereas the third one is found in all of the tissues expressing the gene. Two pFlag-bST6Gal II vector constructions were separately transfected in COS-1 cells in order to express either membrane-bound or soluble active forms of ST6Gal II. Enzymatic assays with these two forms indicated that the enzyme used the LacdiNAc structure (GalNAcbeta1,4GlcNAc) as a better acceptor substrate than the Type II (Galbeta1-4GlcNAc) disaccharide. Moreover, the enzyme's efficiency is improved when the acceptor substrate is provided as a free oligosaccharide rather than as a protein-bound oligosaccharide. In order to investigate the potential role of ST6Gal II during the acute phase of inflammation, we used primary cultures of bovine mammary epithelial cells which were stimulated with pro-inflammatory cytokines. It appears that the ST6Gal II gene was upregulated in cells stimulated by IL-6. This result suggested that alpha2,6-sialylation mediated by this gene could contribute to organism's response to infections.
Collapse
Affiliation(s)
- Benoit Laporte
- UMR1061, Unité de Génétique Moléculaire Animale, Université de Limoges, INRA, IFR N degrees 145 GEIST, France
| | | | | | | |
Collapse
|
16
|
Sialic acids in human health and disease. Trends Mol Med 2008; 14:351-60. [PMID: 18606570 DOI: 10.1016/j.molmed.2008.06.002] [Citation(s) in RCA: 706] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 06/06/2008] [Accepted: 06/06/2008] [Indexed: 12/19/2022]
Abstract
The surfaces of all vertebrate cells are decorated with a dense and complex array of sugar chains, which are mostly attached to proteins and lipids. Most soluble secreted proteins are also similarly decorated with such glycans. Sialic acids are a diverse family of sugar units with a nine-carbon backbone that are typically found attached to the outermost ends of these chains. Given their location and ubiquitous distribution, sialic acids can mediate or modulate a wide variety of physiological and pathological processes. This review considers some examples of their established and newly emerging roles in aspects of human physiology and disease.
Collapse
|
17
|
Surface alpha 2-3- and alpha 2-6-sialylation of human monocytes and derived dendritic cells and its influence on endocytosis. Glycoconj J 2007; 25:259-68. [PMID: 18080182 DOI: 10.1007/s10719-007-9092-6] [Citation(s) in RCA: 257] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 08/24/2007] [Accepted: 11/15/2007] [Indexed: 10/22/2022]
Abstract
Several glycoconjugates are involved in the immune response. Sialic acid is frequently the glycan terminal sugar and it may modulate immune interactions. Dendritic cells (DCs) are antigen-presenting cells with high endocytic capacity and a central role in immune regulation. On this basis, DCs derived from monocytes (mo-DC) are utilised in immunotherapy, though many features are ignored and their use is still limited. We analyzed the surface sialylated glycans expressed during human mo-DC generation. This was monitored by lectin binding and analysis of sialyltransferases (ST) at the mRNA level and by specific enzymatic assays. We showed that alpha 2-3-sialylated O-glycans and alpha 2-6- and alpha 2-3-sialylated N-glycans are present in monocytes and their expression increases during mo-DC differentiation. Three main ST genes are committed with this rearrangement: ST6Gal1 is specifically involved in the augmented alpha 2-6-sialylated N-glycans; ST3Gal1 contributes for the alpha2-3-sialylation of O-glycans, particularly T antigens; and ST3Gal4 may contribute for the increased alpha2-3-sialylated N-glycans. Upon mo-DC maturation, ST6Gal1 and ST3Gal4 are downregulated and ST3Gal1 is altered in a stimulus-dependent manner. We also observed that removing surface sialic acid of immature mo-DC by neuraminidase significantly decreased its endocytic capacity, while it increased in monocytes. Our results indicate the STs expression modulates the increased expression of surface sialylated structures during mo-DC generation, which is probably related with changes in cell mechanisms. The ST downregulation after mo-DC maturation probably results in a decreased sialylation or sialylated glycoconjugates involved in the endocytosis, contributing to the downregulation of one or more antigen-uptake mechanisms specific of mo-DC.
Collapse
|
18
|
Nasirikenari M, Segal BH, Ostberg JR, Urbasic A, Lau JT. Altered granulopoietic profile and exaggerated acute neutrophilic inflammation in mice with targeted deficiency in the sialyltransferase ST6Gal I. Blood 2006; 108:3397-405. [PMID: 16849643 PMCID: PMC1895428 DOI: 10.1182/blood-2006-04-014779] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Elevation of serum sialic acid and the ST6Gal-1 sialyltransferase is part of the hepatic system inflammatory response, but the contribution of ST6Gal-1 has remained unclear. Hepatic ST6Gal-1 elevation is mediated by P1, 1 of 6 promoters regulating the ST6Gal1 gene. We report that the P1-ablated mouse, Siat1DeltaP1, and a globally ST6Gal-1-deficient mouse had significantly increased peritoneal leukocytosis after intraperitoneal challenge with thioglycollate. Exaggerated peritonitis was accompanied by only a modest increase in neutrophil viability, and transferred bone marrow-derived neutrophils from Siat1DeltaP1 mice migrated to the peritonea of recipients with normal efficiency after thioglycollate challenge. Siat1DeltaP1 mice exhibited 3-fold greater neutrophilia by thioglycollate, greater pools of epinephrine-releasable marginated neutrophils, greater sensitivity to G-CSF, elevated bone marrow CFU-G and proliferative-stage myeloid cells, and a more robust recovery from cyclophosphamide-induced myelosuppression. Bone marrow leukocytes from Siat1DeltaP1 are indistinguishable from those of wild-type mice in alpha2,6-sialylation, as revealed by the Sambucus nigra lectin, and in the expression of total ST6Gal-1 mRNA. Together, our study demonstrated a role for ST6Gal-1, possibly from extramedullary sources (eg, produced in liver) in regulating inflammation, circulating neutrophil homeostasis, and replenishing granulocyte numbers.
Collapse
Affiliation(s)
- Mehrab Nasirikenari
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
| | | | | | | | | |
Collapse
|
19
|
Dalziel M, Huang RY, Dall'Olio F, Morris JR, Taylor-Papadimitriou J, Lau JT. Mouse ST6Gal sialyltransferase gene expression during mammary gland lactation. Glycobiology 2001; 11:407-12. [PMID: 11425801 DOI: 10.1093/glycob/11.5.407] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The sialyltransferase ST6Gal mediates the biosynthetic addition of sialic acid, via an alpha2,6 linkage, to the nonreducing end of terminal lactosamine structures. Transcription of the murine ST6Gal gene, Siat1, is regulated by the selective use of multiple promoters in a tissue- and development-specific manner. Here we report that Siat1 mRNA expression is dramatically elevated in lactating (relative to virgin) mouse mammary gland. The predominant ST6Gal mRNA species expressed in lactating mammary gland is a heretofore undocumented isoform containing a unique 5'-untranslated region originating from the mouse Siat1 genetic region, now defined as Exon L, residing 549-bp 5' of the previously characterized Exon X(2). Thus, the novel ST6Gal mRNA form initiates transcription from the region designated as p4 and incorporates the unique sequence from Exon L in 5'-juxtaposition to commonly shared sequences encoded on Exon I to Exon VI. In contrast, cells derived from virgin mammary tissue expressed only the housekeeping mRNA form derived from p3, with Exon O sequence preceding Exons I-VI. The Exon L-containing, p4 class of mRNA was also not detected in a survey of eight other mouse tissues. Previous reports have indicated a strong correlation between mammary cancers and elevated ST6Gal expression in rats and in human patients. However, we uncovered neither elevated expression of ST6Gal mRNA nor appearance of p4 class in mouse breast carcinomas experimentally induced by transformation with the polyoma-middle T oncogene. A number of established breast carcinoma cell lines were also examined, with ST6Gal mRNA and activity generally low. Moreover, with the exception of the Shionogi cell line, p4 class of ST6Gal mRNA was not expressed in any of the mouse breast carcinoma specimens examined. Taken together, our data indicate that murine ST6Gal induction during lactation is achieved by de novo recruitment of a normally silent promoter. Furthermore, the data provide no support for elevated Siat1 expression on the mRNA level in association with murine mammary gland carcinogenesis. With the single exception of the Shionogi cell line, the p3 class remains the predominant ST6Gal mRNA expressed in all other murine mammary carcinoma cells examined.
Collapse
Affiliation(s)
- M Dalziel
- Breast Cancer Biology Group, Imperial Cancer Research Fund, Guy's Hospital, London, U.K
| | | | | | | | | | | |
Collapse
|
20
|
Manzi AE, Norgard-Sumnicht K, Argade S, Marth JD, van Halbeek H, Varki A. Exploring the glycan repertoire of genetically modified mice by isolation and profiling of the major glycan classes and nano-NMR analysis of glycan mixtures. Glycobiology 2000; 10:669-89. [PMID: 10910972 DOI: 10.1093/glycob/10.7.669] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The production of mice with genetic alterations in glycosyltransferases has highlighted the need to isolate and study complex mixtures of the major classes of oligosaccharides (glycans) from intact tissues. We have found that nano-NMR spectroscopy of whole mixtures of N- and O-glycans can complement HPLC profiling methods for elucidating structural details. Working toward obtaining such glycan mixtures from mouse tissues, we decided to develop an approach to isolate not only N- and O-glycans, but also to separate out glycosphingolipids, glycosaminoglycans and glycosylphosphatidylinositol anchors. We describe here a comprehensive Glycan Isolation Protocol that is based primarily upon the physicochemical characteristics of the molecules, and requires only commonly available reagents and equipment. Using radiolabeled internal tracers, we show that recovery of each major class of glycans is as good or better than with conventional approaches for isolating individual classes, and that cross-contamination is minimal. The recovered glycans are of sufficient purity to provide a "glycoprofile" of a cell type or tissue. We applied this approach to compare the N- and O-glycans from wild type mouse tissues with those from mice genetically deficient in glycosyltransferases. N- and O-glycan mixtures from organs of mice deficient in ST6Gal-I (CMP-Sia:Galbeta1-4GlcNAc alpha2-6 sialyltransferase) were studied by the nano-NMR spectroscopy approach, showing no detectable alpha2-6-linked sialic acids. Thus, ST6Gal-I is likely responsible for generating most or all of these residues in normal mice. Similar studies indicate that this linkage is very rare in ganglioside glycans, even in wild-type tissues. In mice deficient in GalNAcT-8 (UDP-GalNAc:polypeptide O-Ser/Thr GalNAc transferase 8), HPLC profiling indicates that O-glycans persist in the thymus in large amounts, without a major change in overall profile, suggesting that other enzymes can synthesize the GalNAc-O-Ser/Thr linkage in this tissue. These results demonstrate the applicability of nano-NMR spectroscopy to complex glycan mixtures, as well as the versatility of the Glycan Isolation Protocol, which makes possible the concurrent examination of multiple glycan classes from intact vertebrate tissues.
Collapse
Affiliation(s)
- A E Manzi
- Departments of Medicine and Cellular and Molecular Medicine, Howard Hughes Medical Institute, University of California San Diego, La Jolla 92093-0687, USA
| | | | | | | | | | | |
Collapse
|
21
|
Kitazume-Kawaguchi S, Dohmae N, Takio K, Tsuji S, Colley KJ. The relationship between ST6Gal I Golgi retention and its cleavage-secretion. Glycobiology 1999; 9:1397-406. [PMID: 10561465 DOI: 10.1093/oxfordjournals.glycob.a018856] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The ST6Gal I is a sialyltransferase that modifies N-linked oligosaccharides of glycoproteins. Previous results suggested a role for luminal stem and active domain sequences in the efficiency of ST6Gal I Golgi retention. Characterization of a series of STtyr isoform deletion mutants demonstrated that the stem is sensitive to proteases and that preventing cleavage in this region leads to increased cell surface expression. A mutant lacking amino acids 32-104 (STDelta4) is not active or cleaved and secreted like the wild type STtyr, but does exhibit increased cell surface expression. It is probable that the STDelta4 mutant lacks the stem region and some amino acids of the active domain because the STDelta5 mutant lacking amino acids 86-104 is also not active but is cleaved and secreted. In contrast, deletion of stem amino acids between residues 32 and 86 in the STDelta1, STDelta2, and STDelta3 mutants does not inactive these enzyme forms, eliminate their cleavage and secretion, or increase their cell surface expression. Surprisingly, cleavage occurs even though the previously identified Asn63-Ser 64 cleavage site is missing. Further evaluation demonstrated that a cleavage site between Lys 40 and Glu 41 is used in COS cells. Mutagenesis of Lys 40 significantly decreased, but did not eliminate cleavage, suggesting that there are additional secondary sites of cleavage in the ST6Gal I stem.
Collapse
Affiliation(s)
- S Kitazume-Kawaguchi
- Department of Biochemistry and Molecular Biology, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612, USA
| | | | | | | | | |
Collapse
|
22
|
Razi N, Varki A. Masking and unmasking of the sialic acid-binding lectin activity of CD22 (Siglec-2) on B lymphocytes. Proc Natl Acad Sci U S A 1998; 95:7469-74. [PMID: 9636173 PMCID: PMC22653 DOI: 10.1073/pnas.95.13.7469] [Citation(s) in RCA: 201] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CD22 is a B cell-restricted glycoprotein involved in signal transduction and modulation of cellular activation. It is also an I-type lectin (now designated Siglec-2), whose extracellular domain can specifically recognize alpha2-6-linked sialic acid (Sia) residues. This activity is postulated to mediate intercellular adhesion and/or to act as a coreceptor in antigen-induced B cell activation. However, studies with recombinant CD22 indicate that the lectin function can be inactivated by expression of alpha2-6-linked Sia residues on the same cell surface. To explore whether this masking phenomenon affects native CD22 on B cells, we first developed a probe to detect the lectin activity of recombinant CD22 expressed on Chinese hamster ovary cells (which have no endogenous alpha2-6-linked Sia residues). This probe is inactive against CD22-positive B lymphoma cells and Epstein-Barr virus-transformed lymphoblasts which express high levels of alpha2-6-linked Sia residues. Enzymatic desialylation unmasks the CD22 lectin activity, indicating that endogenous Sia residues block the CD22 lectin-binding site. Truncation of the side chains of cell surface Sia residues by mild periodate oxidation (known to abrogate Sia recognition by CD22) also had this unmasking effect, indicating that the effects of desialylation are not due to a loss of negative charge. Normal resting B cells from human peripheral blood gave similar findings. However, the lectin is partially unmasked during in vitro activation of these cells. Thus, the lectin activity of CD22 is restricted by endogenous sialylation in resting B cells and may be transiently unmasked during in vivo activation, perhaps to modulate intercellular or intracellular interactions at this critical stage in the humoral response.
Collapse
Affiliation(s)
- N Razi
- Glycobiology Program, University of California, San Diego Cancer Center, Divisions of Hematology-Oncology and Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0687, USA
| | | |
Collapse
|
23
|
Křen V, Thiem J. Ein Multienzymsystem zur Eintopfsynthese des Sialyl-T-Antigens. Angew Chem Int Ed Engl 1995. [DOI: 10.1002/ange.19951070813] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
24
|
Hanasaki K, Powell LD, Varki A. Binding of human plasma sialoglycoproteins by the B cell-specific lectin CD22. Selective recognition of immunoglobulin M and haptoglobin. J Biol Chem 1995; 270:7543-50. [PMID: 7706301 DOI: 10.1074/jbc.270.13.7543] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
CD22 is a cell-surface receptor of resting mature B cells that recognizes sialic acid (Sia) in the natural structure Sia alpha 2-6Gal beta 1-4GlcNAc (Powell, L. D., Jain, R. K., Matta, K. L., Sabesan, S., and Varki, A. (1995) J. Biol. Chem. 270, 7523-7532). Human umbilical vein endothelial cells (HEC) treated with inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) display increases in cell-surface CD22 ligands, caused by increased expression of the enzyme beta-galactoside alpha 2,6-sialyltransferase (Hanasaki, K., Varki, A., Stamenkovic, I., and Bevilacqua, M. P. (1994) J. Biol. Chem. 269, 10637-10643; Hanasaki, K., Varki, A., and Powell, L. D. (1995) J. Biol Chem. 270, 7533-7542). Thus, CD22 could direct potential interactions between mature B cells and endothelial cells during inflammatory states. However, this would have to occur in the presence of blood plasma, which contains many sialoglycoproteins known to carry alpha 2-6-linked sialic acids. We show here that human plasma can indeed inhibit Sia-dependent binding of a recombinant soluble chimeric form of human CD22 (CD22Rg) to TNF-alpha activated HEC. Affinity adsorption of individual human plasma samples with immobilized CD22Rg showed that, of the numerous alpha 2-6-sialic acid containing glycoproteins in plasma, only three polypeptides with apparent molecular mass (under reducing conditions) of 74, 44, and 25 kDa bound, and were specifically eluted with alpha 2-6-sialyllactose. NH2-terminal amino acid sequencing of these high affinity CD22 ligands revealed that they are subunits of immunoglobulin M (IgM) and haptoglobin. Purified human IgM from pooled human plasma can be quantitatively bound by CD22Rg, and binding is blocked by alpha 2-6-sialyllactose, but not by alpha 2-3-sialyllactose. Pretreatment by sialidase or by mild periodate oxidation of sialic acid side chains abolishes these interactions. IgM at physiological concentrations also inhibits CD22Rg binding to TNF-alpha-activated HEC in a manner dependent not only upon its sialylation but also requiring its intact multimeric structure. These data show that CD22 is capable of highly selective recognition of certain multimeric plasma sialoglycoproteins that carry alpha 2-6-linked sialic acids. Notably, the two proteins that are selectively recognized are known to be involved in immune and inflammatory responses. Haptoglobin synthesis by the liver is markedly increased during the "acute phase response" to systemic inflammation, while IgM is the major product resulting from activation of resting CD22-positive B cells.
Collapse
Affiliation(s)
- K Hanasaki
- Cancer Center Division of Cellular and Molecular Medicine, University of California at San Diego, La Jolla 92093-3296, USA
| | | | | |
Collapse
|
25
|
Hanasaki K, Varki A, Powell LD. CD22-mediated cell adhesion to cytokine-activated human endothelial cells. Positive and negative regulation by alpha 2-6-sialylation of cellular glycoproteins. J Biol Chem 1995; 270:7533-42. [PMID: 7706300 DOI: 10.1074/jbc.270.13.7533] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We previously showed that cultured human umbilical vein endothelial cells (HEC) exposed to the inflammatory cytokines tumor necrosis factor-alpha or interleukin-1 display increased activity of beta-galactoside alpha 2,6-sialyltransferase. This is associated with enhanced expression of ligands for the B cell receptor CD22 beta, which recognizes alpha 2-6-linked sialic acids (Hanasaki, K., Varki, A., Stamenkovic, I., and Bevilacqua, M. P. (1994) J. Biol. Chem. 269, 10637-10643). Here we report that increased expression of CD22 ligands is a feature of dermal microvascular endothelial cells as well, and is also observed in response to the cytokine interleukin-4. Tumor necrosis factor-alpha stimulation of HEC causes no change in the profile of endothelial glycoproteins recognized by CD22, but doubles the proportion of total cellular N-linked oligosaccharides capable of binding tightly to CD22. This modest change is sufficient to cause a marked increase in alpha 2-6-linked sialic acid-dependent binding of Chinese hamster ovary (CHO) cells expressing recombinant human CD22. In contrast, B lymphoma cell lines expressing higher levels of cell surface CD22 do not show such sialic acid-dependent binding to activated HEC. Since B lymphoma cells themselves also express high levels of alpha 2-6-linked sialic acids, their CD22 molecules might be rendered nonfunctional by endogenous ligands. In support of this, the lectin function of CD22 can be directly detected on transfected CHO cells, but not on B lymphoma cells. Furthermore, coexpression of beta-galactoside alpha 2,6-sialyltransferase with CD22 in the CHO cells abrogates sialic acid-dependent binding to cytokine-activated HEC. However, such co-transfected cells can bind to B lymphoma cells in a manner apparently less dependent upon alpha 2-6-linked sialic acid, suggesting CD22-mediated interactions that may not be directly dependent on its lectin function. Thus, CD22-mediated interactions between B cells and activated vascular endothelium may be positively regulated by induction of alpha 2-6-linked sialic acid-bearing endothelial cell ligands, but negatively regulated by such ligands on the B cells expressing CD22. Since expression of both CD22 and beta-galactoside alpha 2,6-sialyltransferase are regulated during B cell ontogeny, these findings could be of importance in B cell function and/or trafficking.
Collapse
MESH Headings
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/drug effects
- Antigens, CD/physiology
- Antigens, Differentiation, B-Lymphocyte/biosynthesis
- Antigens, Differentiation, B-Lymphocyte/drug effects
- Antigens, Differentiation, B-Lymphocyte/physiology
- CHO Cells
- Cell Adhesion
- Cell Adhesion Molecules/physiology
- Cell Line
- Cells, Cultured
- Chromatography, Affinity
- Cricetinae
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiology
- Flow Cytometry
- Humans
- Interleukin-4/pharmacology
- Kinetics
- Lectins
- Lymphoma, B-Cell
- Oligosaccharides/isolation & purification
- Oligosaccharides/metabolism
- Sialic Acid Binding Ig-like Lectin 2
- Sialyltransferases/analysis
- Sialyltransferases/metabolism
- Transfection
- Tumor Cells, Cultured
- Tumor Necrosis Factor-alpha/pharmacology
- Umbilical Veins
- beta-D-Galactoside alpha 2-6-Sialyltransferase
Collapse
Affiliation(s)
- K Hanasaki
- Glycobiology Program, UCSD Cancer Center, La Jolla 92093, USA
| | | | | |
Collapse
|
26
|
Gessner P, Riedl S, Quentmaier A, Kemmner W. Enhanced activity of CMP-neuAc:Gal beta 1-4GlcNAc:alpha 2,6-sialyltransferase in metastasizing human colorectal tumor tissue and serum of tumor patients. Cancer Lett 1993; 75:143-9. [PMID: 8313349 DOI: 10.1016/0304-3835(93)90056-f] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The activity of sialyltransferases with different linkage specificities, of a Gal beta 1-4GlcNAc:alpha 2,6-sialyltransferase and a Gal beta 1-4GlcNAc:alpha 2,3-sialyltransferase, was studied in human colorectal tumor tissue from surgical specimens, normal mucosa, liver and liver metastases, and serum of patients suffering from colorectal carcinomas. While alpha 2,3-specific activity was equally high in tumor and mucosa samples, the activity of the alpha 2,6-specific enzyme was increased in tumor tissue and particularly in metastasizing tumors. Also, compared to healthy individuals, serum of patients suffering from metastasizing tumors contained a significantly higher activity of the alpha 2,6-specific enzyme. These results demonstrate that specific sialyltransferase isoforms are expressed in metastasizing tumors and that determination of such isoforms may be a new means for tumor detection and monitoring.
Collapse
Affiliation(s)
- P Gessner
- Institut für Biochemie II, Universität Heidelberg, Germany
| | | | | | | |
Collapse
|