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Flückiger R, Cocuzzi E, Nagaraj RH, Shoham M, Kern TS, Medof ME. DAF in diabetic patients is subject to glycation/inactivation at its active site residues. Mol Immunol 2017; 93:246-252. [PMID: 28886871 DOI: 10.1016/j.molimm.2017.06.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/14/2017] [Accepted: 06/19/2017] [Indexed: 11/30/2022]
Abstract
Decay accelerating factor (DAF or CD55) is a cell associated C3 and C5 convertase regulator originally described in terms of protection of self-cells from systemic complement but now known to modulate adaptive T cell responses. It is expressed on all cell types. We investigated whether nonenzymatic glycation could impair its function and potentially be relevant to complications of diabetes mellitus and other conditions that result in nonenzymatic glycation including cancer, Alzheimer's disease, and aging. Immunoblots of affinity-purified DAF from erythrocytes of patients with diabetes showed pentosidine, glyoxal-AGEs, carboxymethyllysine, and argpyrimidine. HPLC/MS analyses of glucose modified DAF localized the sites of AGE modifications to K125 adjacent to K126, K127 at the junction of CCPs2-3 and spatially near R96, and R100, all identified as being critical for DAF's function. Functional analyses of glucose or ribose treated DAF protein showed profound loss of its regulatory activity. The data argue that de-regulated activation of systemic complement and de-regulated activation of T cells and leukocytes could result from non-enzymatic glycation of DAF.
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Affiliation(s)
| | - Enzo Cocuzzi
- Institute of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Ram H Nagaraj
- Department of Ophthalmology, Case Western Reserve University, Cleveland, OH, USA
| | - Menachem Shoham
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, USA
| | - Timothy S Kern
- Department of Medicine, Case Western Reserve University, Cleveland, OH, USA; Center for Diabetes Research, Case Western Reserve University, Cleveland, OH, USA
| | - M Edward Medof
- Institute of Pathology, Case Western Reserve University, Cleveland, OH, USA; Department of Ophthalmology, Case Western Reserve University, Cleveland, OH, USA; Department of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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2
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Izuhara L, Tatsumi N, Miyagawa S, Iwai S, Watanabe M, Yamanaka S, Katsuoka Y, Nagashima H, Okano HJ, Yokoo T. Generation of a felinized swine endothelial cell line by expression of feline decay-accelerating factor. PLoS One 2015; 10:e0117682. [PMID: 25671605 PMCID: PMC4324824 DOI: 10.1371/journal.pone.0117682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 12/30/2014] [Indexed: 11/19/2022] Open
Abstract
Embryonic stem cell research has facilitated the generation of many cell types for the production of tissues and organs for both humans and companion animals. Because ≥30% of pet cats suffer from chronic kidney disease (CKD), xenotransplantation between pigs and cats has been studied. For a successful pig to cat xenotransplant, the immune reaction must be overcome, especially hyperacute rejection. In this study, we isolated the gene for feline decay-accelerating factor (fDAF), an inhibitor of complement proteins, and transfected a swine endothelial cell line with fDAF to "felinize" the pig cells. These fDAF-expressing cells were resistant to feline serum containing anti-pig antibodies, suggesting that felinized pig cells were resistant to hyperacute rejection. Our results suggest that a "felinized" pig kidney can be generated for the treatment of CKD in cats in the future.
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Affiliation(s)
- Luna Izuhara
- Division of Regenerative Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Norifumi Tatsumi
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
| | - Shuji Miyagawa
- Division of Organ Transplantation, Department of Regenerative Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Satomi Iwai
- Laboratory of Small Animal Surgery I, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Masahito Watanabe
- Meiji University International Institute for Bio-Resource Research, Kawasaki, Japan
| | - Shuichiro Yamanaka
- Division of Regenerative Medicine, The Jikei University School of Medicine, Tokyo, Japan
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yuichi Katsuoka
- Division of Regenerative Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Hiroshi Nagashima
- Meiji University International Institute for Bio-Resource Research, Kawasaki, Japan
| | - Hirotaka J. Okano
- Division of Regenerative Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
- * E-mail:
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3
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Lovett JE, Lovett BW, Harmer J. DEER-Stitch: combining three- and four-pulse DEER measurements for high sensitivity, deadtime free data. J Magn Reson 2012; 223:98-106. [PMID: 22975240 DOI: 10.1016/j.jmr.2012.08.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 07/20/2012] [Accepted: 08/13/2012] [Indexed: 06/01/2023]
Abstract
Over approximately the last 15 years the electron paramagnetic resonance (EPR) technique of double electron electron resonance (DEER) has attracted considerable attention since it allows for the precise measurement of the dipole-dipole coupling between radicals and thus can lead to distance information between pairs of radicals separated by up to ca. 8 nm. The "deadtime free" 4-pulse DEER sequence is widely used but can suffer from poor sensitivity if the electron spin-echo decays too quickly to allow collection of a sufficiently long time trace. In this paper we present a method which takes advantage of the much greater sensitivity that the 3-pulse sequence offers over the 4-pulse sequence since the measured electron spin-echo intensity (for equal sequence lengths) is greater. By combining 3- and 4-pulse DEER time traces using a method coined DEER-Stitch (DEERS) accurate dipole-dipole coupling measurements can be made which combine the sensitivity of the 3-pulse DEER sequence with the deadtime free advantage of the 4-pulse DEER sequence. To develop the DEER-Stitch method three systems were measured: a semi-rigid bis-nitroxide labeled nanowire, the bis-nitroxide labeled protein CD55 with a distance between labels of almost 8 nm and a dimeric copper amine oxidase from Arthrobacter globiformis (AGAO).
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Affiliation(s)
- J E Lovett
- EaStCHEM School of Chemistry, Joseph Black Building, The King's Buildings, Edinburgh EH9 3JJ, UK.
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4
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Hafenstein S, Bowman VD, Chipman PR, Bator Kelly CM, Lin F, Medof ME, Rossmann MG. Interaction of decay-accelerating factor with coxsackievirus B3. J Virol 2007; 81:12927-35. [PMID: 17804498 PMCID: PMC2169128 DOI: 10.1128/jvi.00931-07] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many entero-, parecho-, and rhinoviruses use immunoglobulin (Ig)-like receptors that bind into the viral canyon and are required to initiate viral uncoating during infection. However, some of these viruses use an alternative or additional receptor that binds outside the canyon. Both the coxsackievirus-adenovirus receptor (CAR), an Ig-like molecule that binds into the viral canyon, and decay-accelerating factor (DAF) have been identified as cellular receptors for coxsackievirus B3 (CVB3). A cryoelectron microscopy reconstruction of a variant of CVB3 complexed with DAF shows full occupancy of the DAF receptor in each of 60 binding sites. The DAF molecule bridges the canyon, blocking the CAR binding site and causing the two receptors to compete with one another. The binding site of DAF on CVB3 differs from the binding site of DAF on the surface of echoviruses, suggesting independent evolutionary processes.
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Affiliation(s)
- Susan Hafenstein
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA
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5
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Kuttner-Kondo L, Hourcade DE, Anderson VE, Muqim N, Mitchell L, Soares DC, Barlow PN, Medof ME. Structure-based mapping of DAF active site residues that accelerate the decay of C3 convertases. J Biol Chem 2007; 282:18552-18562. [PMID: 17395591 DOI: 10.1074/jbc.m611650200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Focused complement activation on foreign targets depends on regulatory proteins that decay the bimolecular C3 convertases. Although this process is central to complement control, how the convertases engage and disassemble is not established. The second and third complement control protein (CCP) modules of the cell surface regulator, decay-accelerating factor (DAF, CD55), comprise the simplest structure mediating this activity. Positioning the functional effects of 31 substitution mutants of DAF CCP2 to -4 on partial structures was previously reported. In light of the high resolution crystal structure of the DAF four-CCP functional region, we now reexamine the effects of these and 40 additional mutations. Moreover, we map six monoclonal antibody epitopes and overlap their effects with those of the amino acid substitutions. The data indicate that the interaction of DAF with the convertases is mediated predominantly by two patches approximately 13 A apart, one centered around Arg69 and Arg96 on CCP2 and the other around Phe148 and Leu171 on CCP3. These patches on the same face of the adjacent modules bracket an intermodular linker of critical length (16 A.) Although the key DAF residues in these patches are present or there are conservative substitutions in all other C3 convertase regulators that mediate decay acceleration and/or provide factor I-cofactor activity, the linker region is highly conserved only in the former. Intra-CCP regions also differ. Linker region comparisons suggest that the active CCPs of the decay accelerators are extended, whereas those of the cofactors are tilted. Intra-CCP comparisons suggest that the two classes of regulators bind different regions on their respective ligands.
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Affiliation(s)
- Lisa Kuttner-Kondo
- Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Dennis E Hourcade
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Vernon E Anderson
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106
| | - Nasima Muqim
- Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Lynne Mitchell
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Dinesh C Soares
- Institute of Structural and Molecular Biology and School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, Scotland, United Kingdom
| | - Paul N Barlow
- Institute of Structural and Molecular Biology and School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, Scotland, United Kingdom
| | - M Edward Medof
- Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106.
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6
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Mikesch JH, Schier K, Roetger A, Simon R, Buerger H, Brandt B. The expression and action of decay-accelerating factor (CD55) in human malignancies and cancer therapy. Anal Cell Pathol (Amst) 2007; 28:223-32. [PMID: 17167176 PMCID: PMC4618202 DOI: 10.1155/2006/814816] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Decay-accelerating factor (DAF, CD55) is physiologically acting as an inhibitor of the complement system, but is also broadly expressed in malignant tumours. Here DAF seems to exert different functions beyond its immunological role such as e.g. promotion of tumorigenesis, decrease of complement mediated tumor cell lysis, autocrine loops for cell rescue and evasion of apoptosis, neoangiogenesis, invasiveness, cell motility, and metastasis via oncogenic tyrosine kinase pathways and specific seven-span transmembrane receptors (CD97) binding. Therefore, DAF has already become a target for therapy. In this paper we review the role of DAF in human malignancies as described in different basic, diagnostic and experimental therapeutic studies.
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Affiliation(s)
| | - Kathrin Schier
- Department of Haematology-OncologyUniversity of MuensterGermany
| | | | - Ronald Simon
- Institute of PathologyUniversity Medical Centre Hamburg-EppendorfGermany
| | - Horst Buerger
- Gerhard-Domagk-Institute of PathologyUniversity HospitalWestf.-Wilhelms-Univ. MünsterGermany
| | - Burkhard Brandt
- Tumor BiologyUniversity Medical Centre Hamburg-EppendorfGermany
- *Burkhard Brandt:
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7
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Liszewski MK, Leung MK, Schraml B, Goodship TH, Atkinson JP. Modeling how CD46 deficiency predisposes to atypical hemolytic uremic syndrome. Mol Immunol 2006; 44:1559-68. [PMID: 17027083 PMCID: PMC1828070 DOI: 10.1016/j.molimm.2006.08.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 08/17/2006] [Accepted: 08/22/2006] [Indexed: 12/27/2022]
Abstract
Mutations in complement regulatory proteins predispose to the development of aHUS. Approximately 50% of patients bear a mutation in one of three complement control proteins, factor H, factor I, or membrane cofactor protein (MCP; CD46). Another membrane regulator that is closely related to MCP, decay accelerating factor (DAF; CD55) thus far has shown no association with aHUS and continues to be investigated. The goal of this study was to compare the regulatory profile of MCP and DAF and to assess how alterations in MCP predispose to complement dysregulation. We employed a model system of complement activation on Chinese hamster ovary (CHO) cell transfectants. The four regularly expressed isoforms of MCP and DAF inhibited C3b deposition by the alternative pathway. DAF, but not MCP, inhibited the classical pathway. Most patients with MCP-aHUS are heterozygous and express only 25-50% of the wild-type protein. We, therefore, analyzed the effect of reduced levels of wild-type MCP and found that cells with lowered expression levels were less efficient in inhibiting alternative pathway activation. Further, a dysfunctional MCP mutant, expressed at normal levels and identified in five patients with aHUS (S206P), failed to protect against C3b amplification on CHO cells, even if expression levels were increased 10-fold. Our results add new information relative to the necessity for appropriate expression levels of MCP and further implicate the alternative pathway in disease processes such as aHUS.
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Affiliation(s)
- M. Kathryn Liszewski
- Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8045, St. Louis, MO 63110 USA
| | - Marilyn K. Leung
- Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8045, St. Louis, MO 63110 USA
| | - Barbara Schraml
- Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8045, St. Louis, MO 63110 USA
| | | | - John P. Atkinson
- Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8045, St. Louis, MO 63110 USA
- *Corresponding author. Tel.: 314-362-8391; fax 314-362-1366; e-mail address:
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8
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Korotkova N, Cota E, Lebedin Y, Monpouet S, Guignot J, Servin AL, Matthews S, Moseley SL. A subfamily of Dr adhesins of Escherichia coli bind independently to decay-accelerating factor and the N-domain of carcinoembryonic antigen. J Biol Chem 2006; 281:29120-30. [PMID: 16882658 PMCID: PMC2629542 DOI: 10.1074/jbc.m605681200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Escherichia coli expressing the Dr family of adhesins adheres to epithelial cells by binding to decay-accelerating factor (DAF) and carcinoembryonic antigen (CEA)-related cell surface proteins. The attachment of bacteria expressing Dr adhesins to DAF induces clustering of DAF around bacterial cells and also recruitment of CEA-related cell adhesion molecules. CEA, CEACAM1, and CEACAM6 have been shown to serve as receptors for some Dr adhesins (AfaE-I, AfaE-III, DraE, and DaaE). We demonstrate that AfaE-I, AfaE-V, DraE, and DaaE adhesins bind to the N-domain of CEA. To identify the residues involved in the N-CEA/DraE interaction, we performed SPR binding analyses of naturally occurring variants and a number of randomly generated mutants in DraE and N-CEA. Additionally, we used chemical shift mapping by NMR to determine the surface of DraE involved in N-CEA binding. These results show a distinct CEA binding site located primarily in the A, B, E, and D strands of the Dr adhesin. Interestingly, this site is located opposite to the beta-sheet encompassing the previously determined binding site for DAF, which implies that the adhesin can bind simultaneously to both receptors on the epithelial cell surface. The recognition of CEACAMs from a highly diverse DrCEA subfamily of Dr adhesins indicates that interaction with these receptors plays an important role in niche adaptation of E. coli strains expressing Dr adhesins.
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Affiliation(s)
- Natalia Korotkova
- Department of Microbiology, University of Washington, Seattle, Washington 98195-7242, USA
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9
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Goodfellow IG, Evans DJ, Blom AM, Kerrigan D, Miners JS, Morgan BP, Spiller OB. Inhibition of coxsackie B virus infection by soluble forms of its receptors: binding affinities, altered particle formation, and competition with cellular receptors. J Virol 2005; 79:12016-24. [PMID: 16140777 PMCID: PMC1212587 DOI: 10.1128/jvi.79.18.12016-12024.2005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously reported that soluble decay-accelerating factor (DAF) and coxsackievirus-adenovirus receptor (CAR) blocked coxsackievirus B3 (CVB3) myocarditis in mice, but only soluble CAR blocked CVB3-mediated pancreatitis. Here, we report that the in vitro mechanisms of viral inhibition by these soluble receptors also differ. Soluble DAF inhibited virus infection through the formation of reversible complexes with CVB3, while binding of soluble CAR to CVB induced the formation of altered (A) particles with a resultant irreversible loss of infectivity. A-particle formation was characterized by loss of VP4 from the virions and required incubation of CVB3-CAR complexes at 37 degrees C. Dimeric soluble DAF (DAF-Fc) was found to be 125-fold-more effective at inhibiting CVB3 than monomeric DAF, which corresponded to a 100-fold increase in binding affinity as determined by surface plasmon resonance analysis. Soluble CAR and soluble dimeric CAR (CAR-Fc) bound to CVB3 with 5,000- and 10,000-fold-higher affinities than the equivalent forms of DAF. While DAF-Fc was 125-fold-more effective at inhibiting virus than monomeric DAF, complement regulation by DAF-Fc was decreased 4 fold. Therefore, while the virus binding was a cooperative event, complement regulation was hindered by the molecular orientation of DAF-Fc, indicating that the regions responsible for complement regulation and virus binding do not completely overlap. Relative contributions of CVB binding affinity, receptor binding footprint on the virus capsid, and induction of capsid conformation alterations for the ability of cellular DAF and CAR to act as receptors are discussed.
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Affiliation(s)
- Ian G Goodfellow
- School of Animal and Microbial Sciences, University of Reading, United Kingdom
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10
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Brandt B, Mikesch JH, Simon R, Rötger A, Kemming D, Schier K, Sauter G, Bürger H. Selective expression of a splice variant of decay-accelerating factor in c-erbB-2-positive mammary carcinoma cells showing increased transendothelial invasiveness. Biochem Biophys Res Commun 2005; 329:318-23. [PMID: 15721309 DOI: 10.1016/j.bbrc.2005.01.138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Indexed: 10/25/2022]
Abstract
By differential-display-PCR a subclone of the SK-BR-3 cell line with high in vitro transendothelial invasiveness was identified to express increased levels of a new alternative splice variant of decay-accelerating factor (DAF). DAF seems to play an important role in some malignant tumours since on the one hand the expression of complement inhibitors on the surface of tumour cells prevents the accumulation of complement factors and in consequence cell lysis. On the other hand, DAF has been identified as a ligand for the CD97 surface receptor which induces cell migration. Immunofluorescence procedures, Western blot analyses, and cDNA clone sequencing were employed to confirm the expression of DAF restricted to invasive tumour cells. Using a radioactive RNA-in situ hybridisation on freshly frozen tissue microarrays and RT-PCR on native tumour tissue, the expression of alternative spliced DAF mRNA was demonstrated in invasive breast cancer. Due to the fact that it could thereby not be detected in normal mammary tissues, it has to be confirmed in larger studies that the DAF splice variant might be a specific tumour marker for invasive breast cancer.
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MESH Headings
- Alternative Splicing
- Antigens, CD
- Base Sequence
- Biomarkers, Tumor
- Blotting, Western
- Breast Neoplasms/metabolism
- CD55 Antigens/biosynthesis
- CD55 Antigens/chemistry
- Cell Movement
- Cloning, Molecular
- Complement Inactivator Proteins/chemistry
- Complement System Proteins/metabolism
- DNA, Complementary/metabolism
- Electrophoresis, Agar Gel
- Endothelium, Vascular/cytology
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
- Humans
- Immunohistochemistry
- In Situ Hybridization
- Ligands
- Membrane Glycoproteins/biosynthesis
- Microscopy, Fluorescence
- Molecular Sequence Data
- Neoplasm Invasiveness
- Oligonucleotide Array Sequence Analysis
- Polymerase Chain Reaction
- RNA/metabolism
- RNA, Messenger/metabolism
- Receptor, ErbB-2/biosynthesis
- Receptor, ErbB-2/metabolism
- Receptors, G-Protein-Coupled
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- Burkhard Brandt
- Institute of Clinical Chemistry and Laboratory Medicine, University of Muenster, Germany.
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11
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Miyagawa S. [Complement regulatory proteins]. Nihon Rinsho 2005; 63 Suppl 4:274-8. [PMID: 15861668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Affiliation(s)
- Shuji Miyagawa
- Department of Regenerative Medicine, Osaka University Graduate School of Medicine
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12
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Lublin DM. Review: Cromer and DAF: role in health and disease. Immunohematology 2005; 21:39-47. [PMID: 15954803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The antigens of the Cromer blood group system are located on the protein decay-accelerating factor (DAF). This system consists of ten high-prevalence and three low-prevalence antigens; the molecular basis for all of these antigens is a single nucleotide polymorphism in the DAF gene. DAF is a 70,000-Da plasma membrane protein that is widely distributed on all blood cells and on endothelial and epithelial tissues. The physiological role of DAF is to inhibit the complement cascade at the level of the critical C3 convertase step. By this mechanism,DAF acts to protect autologous cells and tissues from complement-mediated damage and hence can play a role in preventing or modulating autoimmune disease and inflammation. The use of recombinant DAF as a therapeutic agent in autoimmunity and inflammation, and of DAF transgenic animals in xenotransplantation, is being actively investigated. Additionally, DAF serves as a receptor for certain strains of Escherichia coli and certain types of enteroviruses. The DAF protein that contains the Cromer antigens serves important roles in health and disease.
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Affiliation(s)
- D M Lublin
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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13
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Blanc E, Roversi P, Vonrhein C, Flensburg C, Lea SM, Bricogne G. Refinement of severely incomplete structures with maximum likelihood in BUSTER-TNT. Acta Crystallogr D Biol Crystallogr 2004; 60:2210-21. [PMID: 15572774 DOI: 10.1107/s0907444904016427] [Citation(s) in RCA: 612] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Accepted: 07/06/2004] [Indexed: 11/10/2022]
Abstract
BUSTER-TNT is a maximum-likelihood macromolecular refinement package. BUSTER assembles the structural model, scales observed and calculated structure-factor amplitudes and computes the model likelihood, whilst TNT handles the stereochemistry and NCS restraints/constraints and shifts the atomic coordinates, B factors and occupancies. In real space, in addition to the traditional atomic and bulk-solvent models, BUSTER models the parts of the structure for which an atomic model is not yet available ('missing structure') as low-resolution probability distributions for the random positions of the missing atoms. In reciprocal space, the BUSTER structure-factor distribution in the complex plane is a two-dimensional Gaussian centred around the structure factor calculated from the atomic, bulk-solvent and missing-structure models. The errors associated with these three structural components are added to compute the overall spread of the Gaussian. When the atomic model is very incomplete, modelling of the missing structure and the consistency of the BUSTER statistical model help structure building and completion because (i) the accuracy of the overall scale factors is increased, (ii) the bias affecting atomic model refinement is reduced by accounting for some of the scattering from the missing structure, (iii) the addition of a spatial definition to the source of incompleteness improves on traditional Luzzati and sigmaA-based error models and (iv) the program can perform selective density modification in the regions of unbuilt structure alone.
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Affiliation(s)
- E Blanc
- Global Phasing Ltd, Sheraton House, Castle Park, Cambridge CB3 0AX, England
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14
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Pettigrew D, Anderson KL, Billington J, Cota E, Simpson P, Urvil P, Rabuzin F, Roversi P, Nowicki B, du Merle L, Le Bouguénec C, Matthews S, Lea SM. High Resolution Studies of the Afa/Dr Adhesin DraE and Its Interaction with Chloramphenicol. J Biol Chem 2004; 279:46851-7. [PMID: 15331605 DOI: 10.1074/jbc.m409284200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pathogenic Escherichia coli expressing Afa/Dr adhesins are able to cause both urinary tract and diarrheal infections. The Afa/Dr adhesins confer adherence to epithelial cells via interactions with the human complement regulating protein, decay accelerating factor (DAF or CD55). Two of the Afa/Dr adhesions, AfaE-III and DraE, differ from each other by only three residues but are reported to have several different properties. One such difference is disruption of the interaction between DraE and CD55 by chloramphenicol, whereas binding of AfaE-III to CD55 is unaffected. Here we present a crystal structure of a strand-swapped trimer of wild type DraE. We also present a crystal structure of this trimer in complex with chloramphenicol, as well as NMR data supporting the binding position of chloramphenicol within the crystal. The crystal structure reveals the precise atomic basis for the sensitivity of DraE-CD55 binding to chloramphenicol and demonstrates that in contrast to other chloramphenicol-protein complexes, drug binding is mediated via recognition of the chlorine "tail" rather than via intercalation of the benzene rings into a hydrophobic pocket.
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Affiliation(s)
- David Pettigrew
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
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15
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White J, Lukacik P, Esser D, Steward M, Giddings N, Bright JR, Fritchley SJ, Morgan BP, Lea SM, Smith GP, Smith RAG. Biological activity, membrane-targeting modification, and crystallization of soluble human decay accelerating factor expressed in E. coli. Protein Sci 2004; 13:2406-15. [PMID: 15322283 PMCID: PMC2280017 DOI: 10.1110/ps.03455604] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Decay-accelerating factor (DAF, CD55) is a glycophosphatidyl inositol-anchored glycoprotein that regulates the activity of C3 and C5 convertases. In addition to understanding the mechanism of complement inhibition by DAF through structural studies, there is also an interest in the possible therapeutic potential of the molecule. In this report we describe the cloning, expression in Escherichia coli, isolation and membrane-targeting modification of the four short consensus repeat domains of soluble human DAF with an additional C-terminal cysteine residue to permit site-specific modification. The purified refolded recombinant protein was active against both classical and alternative pathway assays of complement activation and had similar biological activity to soluble human DAF expressed in Pichia pastoris. Modification with a membrane-localizing peptide restored cell binding and gave a large increase in antihemolytic potency. These data suggested that the recombinant DAF was correctly folded and suitable for structural studies as well as being the basis for a DAF-derived therapeutic. Crystals of the E. coli-derived protein were obtained and diffracted to 2.2 A, thus permitting the first detailed X-ray crystallography studies on a functionally active human complement regulator protein with direct therapeutic potential.
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Affiliation(s)
- Jennifer White
- Adprotech Ltd., Chesterford Research Park, Little Chesterford, Saffron Walden, Essex CB10 1XL, UK
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16
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Anderson KL, Billington J, Pettigrew D, Cota E, Simpson P, Roversi P, Chen HA, Urvil P, du Merle L, Barlow PN, Medof ME, Smith RAG, Nowicki B, Le Bouguénec C, Lea SM, Matthews S. An Atomic Resolution Model for Assembly, Architecture, and Function of the Dr Adhesins. Mol Cell 2004; 15:647-57. [PMID: 15327779 DOI: 10.1016/j.molcel.2004.08.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2004] [Revised: 06/04/2004] [Accepted: 06/09/2004] [Indexed: 11/16/2022]
Abstract
Pathogenic bacteria possess adhesion protein complexes that play essential roles in targeting host cells and in propagating infection. Although each family of adhesion proteins is generally associated with a specific human disease, the Dr family from Escherichia coli is a notable exception, as its members are associated with both diarrheal and urinary tract infections. These proteins are reported to form both fimbrial and afimbrial structures at the bacterial cell surface and target a common host cell receptor, the decay-accelerating factor (DAF or CD55). Using the newly solved three-dimensional structure of AfaE, we have constructed a robust atomic resolution model that reveals the structural basis for assembly by donor strand complementation and for the architecture of capped surface fibers.
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Affiliation(s)
- Kirstine L Anderson
- Department of Biological Sciences, Wolfson Laboratories, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
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17
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Williams DT, Chaudhry Y, Goodfellow IG, Lea S, Evans DJ. Interactions of decay-accelerating factor (DAF) with haemagglutinating human enteroviruses: utilizing variation in primate DAF to map virus binding sites. J Gen Virol 2004; 85:731-738. [PMID: 14993659 DOI: 10.1099/vir.0.19674-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A cellular receptor for the haemagglutinating enteroviruses (HEV), and the protein that mediates haemagglutination, is the membrane complement regulatory protein decay accelerating factor (DAF; CD55). Although primate DAF is highly conserved, significant differences exist to enable cell lines derived from primates to be utilized for the characterization of the DAF binding phenotype of human enteroviruses. Thus, several distinct DAF-binding phenotypes of a selection of HEVs (viz. coxsackievirus A21 and echoviruses 6, 7, 11-13, 29) were identified from binding and infection assays using a panel of primate cells derived from human, orang-utan, African Green monkey and baboon tissues. These studies complement our recent determination of the crystal structure of SCR(34) of human DAF [Williams, P., Chaudhry, Y., Goodfellow, I. G., Billington, J., Powell, R., Spiller, O. B., Evans, D. J. & Lea, S. (2003). J Biol Chem 278, 10691-10696] and have enabled us to better map the regions of DAF with which enteroviruses interact and, in certain cases, predict specific virus-receptor contacts.
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Affiliation(s)
- David T Williams
- Faculty of Biomedical and Life Sciences, Division of Virology, University of Glasgow, Glasgow G11 5JR, UK
| | - Yasmin Chaudhry
- Faculty of Biomedical and Life Sciences, Division of Virology, University of Glasgow, Glasgow G11 5JR, UK
| | - Ian G Goodfellow
- Faculty of Biomedical and Life Sciences, Division of Virology, University of Glasgow, Glasgow G11 5JR, UK
| | - Susan Lea
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, Oxford, UK
| | - David J Evans
- Faculty of Biomedical and Life Sciences, Division of Virology, University of Glasgow, Glasgow G11 5JR, UK
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18
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Lukacik P, Roversi P, White J, Esser D, Smith GP, Billington J, Williams PA, Rudd PM, Wormald MR, Harvey DJ, Crispin MDM, Radcliffe CM, Dwek RA, Evans DJ, Morgan BP, Smith RAG, Lea SM. Complement regulation at the molecular level: the structure of decay-accelerating factor. Proc Natl Acad Sci U S A 2004; 101:1279-84. [PMID: 14734808 PMCID: PMC337044 DOI: 10.1073/pnas.0307200101] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Indexed: 11/18/2022] Open
Abstract
The human complement regulator CD55 is a key molecule protecting self-cells from complement-mediated lysis. X-ray diffraction and analytical ultracentrifugation data reveal a rod-like arrangement of four short consensus repeat (SCR) domains in both the crystal and solution. The stalk linking the four SCR domains to the glycosylphosphatidylinositol anchor is extended by the addition of 11 highly charged O-glycans and positions the domains an estimated 177 A above the membrane. Mutation mapping and hydrophobic potential analysis suggest that the interaction with the convertase, and thus complement regulation, depends on the burial of a hydrophobic patch centered on the linker between SCR domains 2 and 3.
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Affiliation(s)
- P Lukacik
- Laboratory of Molecular Biophysics and Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England
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19
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Blumenthal RD. Technology evaluation: Onyvax-105, Onyvax. Curr Opin Mol Ther 2003; 5:668-72. [PMID: 14755894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Onyvax, under license from the Cancer Research Campaign, is developing Onyvax-105 (105AD7), an anti-idiotype monoclonal antibody, for the potential treatment of colorectal cancer. Onyvax initiated phase II clinical trials in May 2000.
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20
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Lawrence DW, Bruyninckx WJ, Louis NA, Lublin DM, Stahl GL, Parkos CA, Colgan SP. Antiadhesive role of apical decay-accelerating factor (CD55) in human neutrophil transmigration across mucosal epithelia. ACTA ACUST UNITED AC 2003; 198:999-1010. [PMID: 14530374 PMCID: PMC2194216 DOI: 10.1084/jem.20030380] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neutrophil migration across mucosal epithelium during inflammatory episodes involves the precise orchestration of a number a cell surface molecules and signaling pathways. After successful migration to the apical epithelial surface, apically localized epithelial proteins may serve to retain PMN at the lumenal surface. At present, identification of apical epithelial ligands and their PMN counter-receptors remain elusive. Therefore, to define the existence of apical epithelial cell surface proteins involved in PMN–epithelial interactions, we screened a panel of antibodies directed against epithelial plasma membranes. This strategy identified one antibody (OE-1) that both localized to the apical cell membrane and significantly inhibited PMN transmigration across epithelial monolayers. Microsequence analysis revealed that OE-1 recognized human decay-accelerating factor (DAF, CD55). DAF is a highly glycosylated, 70–80-kD, glycosyl-phosphatidyinositol–linked protein that functions predominantly as an inhibitor of autologous complement lysis. DAF suppression experiments using antisense oligonucleotides or RNA interference revealed that DAF may function as an antiadhesive molecule promoting the release of PMN from the lumenal surface after transmigration. Similarly, peptides corresponding to the antigen recognition domain of OE-1 resulted in accumulation of PMN on the apical epithelial surface. The elucidation of DAF as an apical epithelial ligand for PMN provides a target for novel anti-inflammatory therapies directed at quelling unwanted inflammatory episodes.
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Affiliation(s)
- Donald W Lawrence
- Center for Experimental Therapeutics and Reperfusion Injury, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck St., Boston, MA 02115, USA
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21
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Uhrinova S, Lin F, Ball G, Bromek K, Uhrin D, Medof ME, Barlow PN. Solution structure of a functionally active fragment of decay-accelerating factor. Proc Natl Acad Sci U S A 2003; 100:4718-23. [PMID: 12672958 PMCID: PMC153622 DOI: 10.1073/pnas.0730844100] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The second and third modules of human decay accelerating factor (DAF) are necessary and sufficient to accelerate decay of the classical pathway (CP) convertase of complement. No structure of a mammalian protein with decay-accelerating activity has been available to date. We therefore determined the solution structure of DAF modules 2 and 3 (DAF approximately 2,3). Structure-guided analysis of 24 mutants identified likely contact points between DAF and the CP convertase. Three (R96, R69, and a residue in the vicinity of L171) lie on DAF approximately 2,3's concave face. A fourth, consisting of K127 and nearby R100, is on the opposite face. Regions of module 3 remote from the semiflexible 2-3 interface seem not to be involved in binding to the CP convertase. DAF thus seems to occupy a groove on the CP convertase such that both faces of DAF close to the 2-3 junction (including a positively charged region that encircles the protein at this point) interact simultaneously. Alternative pathway convertase interactions with DAF require additional regions of CCP 3 lying away from the 2-3 interface, consistent with the established additional requirement of module 4 for alternative pathway regulation.
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Affiliation(s)
- Stanislava Uhrinova
- Edinburgh Protein Interaction Centre, University of Edinburgh, Edinburgh EH9 3JJ, Scotland
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22
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Williams P, Chaudhry Y, Goodfellow IG, Billington J, Powell R, Spiller OB, Evans DJ, Lea S. Mapping CD55 function. The structure of two pathogen-binding domains at 1.7 A. J Biol Chem 2003; 278:10691-6. [PMID: 12499389 DOI: 10.1074/jbc.m212561200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Decay-accelerating factor (CD55), a regulator of the alternative and classical pathways of complement activation, is expressed on all serum-exposed cells. It is used by pathogens, including many enteroviruses and uropathogenic Escherichia coli, as a receptor prior to infection. We describe the x-ray structure of a pathogen-binding fragment of human CD55 at 1.7 A resolution containing two of the three domains required for regulation of human complement. We have used mutagenesis to map biological functions onto the molecule; decay-accelerating activity maps to a single face of the molecule, whereas bacterial and viral pathogens recognize a variety of different sites on CD55.
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Affiliation(s)
- Pamela Williams
- Laboratory of Molecular Biophysics, Department of Biochemistry, University of Oxford, United Kingdom
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23
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Fukuta D, Miyagawa S, Yamada M, Matsunami K, Kurihara T, Shirasu A, Hattori H, Shirakura R. Various forms of DAF (CD55) and C1 esterase inhibitor. Transplant Proc 2003; 35:519-20. [PMID: 12591512 DOI: 10.1016/s0041-1345(02)03828-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- D Fukuta
- Division of Organ Transplantation (E9), Department of Regenerative Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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24
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Spiller OB, Robinson M, O'Donnell E, Milligan S, Morgan BP, Davison AJ, Blackbourn DJ. Complement regulation by Kaposi's sarcoma-associated herpesvirus ORF4 protein. J Virol 2003; 77:592-9. [PMID: 12477863 PMCID: PMC140610 DOI: 10.1128/jvi.77.1.592-599.2003] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2002] [Accepted: 09/30/2002] [Indexed: 11/20/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with three types of human tumor: Kaposi's sarcoma, multicentric Castleman's disease, and primary effusion lymphoma. The virus encodes a number of proteins that participate in disrupting the immune response, one of which was predicted by sequence analysis to be encoded by open reading frame 4 (ORF4). The predicted ORF4 protein shares homology with cellular proteins referred to as regulators of complement activation. In the present study, the transcription profile of the ORF4 gene was characterized, revealing that it encodes at least three transcripts, by alternative splicing mechanisms, and three protein isoforms. Functional studies revealed that each ORF4 protein isoform inhibits complement and retains a C-terminal transmembrane domain. Consistent with the complement-regulating activity, we propose to name the proteins encoded by the ORF4 gene collectively as KSHV complement control protein (KCP). KSHV ORF4 is the most complex alternatively spliced gene encoding a viral complement regulator described to date. KCP inhibits the complement component of the innate immune response, thereby possibly contributing to the in vivo persistence and pathogenesis of this virus.
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Affiliation(s)
- O Brad Spiller
- Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff CF14 4XX, United Kingdom
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25
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Abstract
Decay Accelerating Factor (or CD55) is a major regulator of the alternative and classical pathways of complement activation and is expressed on all serum-exposed cells. It is commonly hijacked by invading pathogens, including many enteroviruses and uropathogenic Escherichia coli, to promote cellular attachment prior to infection. This review will attempt to summarize our knowledge about these interactions between CD55 and various pathogens and also what is known about the non-complement interaction between CD55 and CD97.
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Affiliation(s)
- S Lea
- Laboratory of Molecular Biophysics, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK.
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26
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He Y, Lin F, Chipman PR, Bator CM, Baker TS, Shoham M, Kuhn RJ, Medof ME, Rossmann MG. Structure of decay-accelerating factor bound to echovirus 7: a virus-receptor complex. Proc Natl Acad Sci U S A 2002; 99:10325-9. [PMID: 12119400 PMCID: PMC124913 DOI: 10.1073/pnas.152161599] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2002] [Indexed: 11/18/2022] Open
Abstract
Echoviruses are enteroviruses that belong to Picornaviridae. Many echoviruses use decay-accelerating factor (DAF) as their cellular receptor. DAF is a glycosylphosphatidyl inositol-anchored complement regulatory protein found on most cell surfaces. It functions to protect cells from complement attack. The cryo-electron microscopy reconstructions of echovirus 7 complexed with DAF show that the DAF-binding regions are located close to the icosahedral twofold axes, in contrast to other enterovirus complexes where the viral canyon is the receptor binding site. This novel receptor binding position suggests that DAF is important for the attachment of viral particles to host cells, but probably not for initiating viral uncoating, as is the case with canyon-binding receptors. Thus, a different cell entry mechanism must be used for enteroviruses that bind DAF.
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Affiliation(s)
- Yongning He
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1392, USA
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27
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Hasan RJ, Pawelczyk E, Urvil PT, Venkatarajan MS, Goluszko P, Kur J, Selvarangan R, Nowicki S, Braun WA, Nowicki BJ. Structure-function analysis of decay-accelerating factor: identification of residues important for binding of the Escherichia coli Dr adhesin and complement regulation. Infect Immun 2002; 70:4485-93. [PMID: 12117960 PMCID: PMC128121 DOI: 10.1128/iai.70.8.4485-4493.2002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Decay-accelerating factor (DAF), a complement regulatory protein, also serves as a receptor for Dr adhesin-bearing Escherichia coli. The repeat three of DAF was shown to be important in Dr adhesin binding and complement regulation. However, Dr adhesins do not bind to red blood cells with the rare polymorphism of DAF, designated Dr(a(-)); these cells contain a point mutation (Ser165-Leu) in DAF repeat three. In addition, monoclonal antibody IH4 specific against repeat three was shown to block both Dr adhesin binding and complement regulatory functions of DAF. Therefore, to identify residues important in binding of Dr adhesin and IH4 and in regulating complement, we mutated 11 amino acids-predominantly those in close proximity to Ser165 to alanine-and expressed these mutations in Chinese hamster ovary cells. To map the mutations, we built a homology model of repeat three based on the poxvirus complement inhibitory protein, using the EXDIS, DIAMOD, and FANTOM programs. We show that perhaps Ser155, and not Ser165, is the key amino acid that interacts with the Dr adhesin and amino acids Gly159, Tyr160, and Leu162 and also aids in binding Dr adhesin. The IH4 binding epitope contains residues Phe148, Ser155, and L171. Residues Phe123 and Phe148 at the interface of repeat 2-3, and also Phe154 in the repeat three cavity, were important for complement regulation. Our results show that residues affecting the tested functions are located on the same loop (148 to 171), at the same surface of repeat three, and that the Dr adhesin-binding and complement regulatory epitopes of DAF appear to be distinct and are approximately 20 A apart.
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Affiliation(s)
- Rafia J Hasan
- Department of Obstetrics & Gynecology, The University of Texas Medical Branch, Galveston 77555-1062, USA
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28
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Uhrínová S, Lin F, Uhrín D, Medof ME, Barlow PN. Resonance assignments of the central complement control protein module pair of human decay accelerating factor. J Biomol NMR 2002; 23:167-168. [PMID: 12153048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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29
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Gousset K, Wolkers WF, Tsvetkova NM, Oliver AE, Field CL, Walker NJ, Crowe JH, Tablin F. Evidence for a physiological role for membrane rafts in human platelets. J Cell Physiol 2002; 190:117-28. [PMID: 11807818 DOI: 10.1002/jcp.10039] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We have investigated raft formation in human platelets in response to cell activation. Lipid phase separation and domain formation were detected using the fluorescent dye 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate (diI-C(18)) that preferentially partitions into gel-like lipid domains. We showed that when human platelets are activated by cold and physiological agonists, rafts coalesce into visible aggregates. These events were disrupted by depletion of membrane cholesterol. Using Fourier transform infrared spectroscopy (FTIR), we measured a thermal phase transition at around 30 degrees C in intact platelets, which we have assigned as the liquid-ordered to the liquid-disordered phase transition of rafts. Phase separation of the phospholipid and the sphingomyelin-enriched rafts could be observed as two phase transitions at around 15 and 30 degrees C, respectively. The higher transition, assigned to the rafts, was greatly enhanced with removal of membrane cholesterol. Detergent-resistant membranes (DRMs) were enriched in cholesterol (50%) and sphingomyelin (20%). The multi-functional platelet receptor CD36 selectively partitioned into DRMs, whereas the GPI-linked protein CD55 and the major platelet integrin alpha(IIb)beta(3a) did not, which suggests that the clustering of proteins within rafts is a regulated process dependent on specific lipid protein interactions. We suggest that raft aggregation is a dynamic, reversible physiological event triggered by cell activation.
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Affiliation(s)
- Karine Gousset
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, 2315 Haring Hall, University of California-Davis, Davis, CA 95616, USA.
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30
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Abstract
We report the use of methylotrophic yeast Pichia pastoris as a host to efficiently express complement control protein repeats (CCPs) 1-4 of mouse decay accelerating factor (DAF, CD55) as a soluble protein. With this system, the mouse DAF CCP1-4-active-domain-containing module linked to a 6x His tag at its C terminus was secreted into the culture supernatant at 15 mg/L after 24 h of induction with methanol. A mouse DAF CCP1-4 mutant protein in which its two potential N-glycosylation sites were deleted by changing Asn(187) and Asn(262) to Gln was also produced. Using Ni(2+)-immobilized agarose affinity chromatography, the recombinant mouse DAF modules with their 6x His tags could be one-step isolated to SDS-PAGE purity. Polyclonal antibody against native mouse DAF CCP1-4 was raised by immunizing NZW rabbits with the purified product. Measurements of the bioactivities of the wild-type and mutant mouse DAF proteins in C3b uptake assays showed no differences in regulatory activities in either the classical or the alternative pathways. With the use of the mutant DAF protein, small rod-shaped crystals were produced and preliminary data obtained. The production of large quantities of functional recombinant mouse DAF CCP1-4 modules and their antibody offers the opportunity to study DAF structure and DAF function in vivo.
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Affiliation(s)
- F Lin
- Institute of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
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31
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Abstract
Decay-accelerating factor (DAF) is a complement regulator that dissociates autologous C3 convertases, which assemble on self cell surfaces. Its activity resides in the last three of its four complement control protein repeats (CCP2-4). Previous modeling on the nuclear magnetic resonance structure of CCP15-16 in the serum C3 convertase regulator factor H proposed a positively charged surface area on CCP2 extending into CCP3, and hydrophobic moieties between CCPs 2 and 3 as being primary convertase-interactive sites. To map the residues providing for the activity of DAF, we analyzed the functions of 31 primarily alanine substitution mutants based in part on this model. Replacing R69, R96, R100, and K127 in the positively charged CCP2-3 groove or hydrophobic F148 and L171 in CCP3 markedly impaired the function of DAF in both activation pathways. Significantly, mutations of K126 and F169 and of R206 and R212 in downstream CCP4 selectively reduced alternative pathway activity without affecting classical pathway activity. Rhesus macaque DAF has all the above human critical residues except for F169, which is an L, and its CCPs exhibited full activity against the human classical pathway C3 convertase. The recombinants whose function was preferentially impaired against the alternative pathway C3bBb compared with the classical pathway C4b2a were tested in classical pathway C5 convertase (C4b2a3b) assays. The effects on C4b2a and C4b2a3b were comparable, indicating that DAF functions similarly on the two enzymes. When CCP2-3 of DAF were oriented according to the crystal structure of CCP1-2 of membrane cofactor protein, the essential residues formed a contiguous region, suggesting a similar spatial relationship.
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Affiliation(s)
- L A Kuttner-Kondo
- Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
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32
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Durrant LG, Spendlove I. Immunization against tumor cell surface complement-regulatory proteins. Curr Opin Investig Drugs 2001; 2:959-66. [PMID: 11757799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Complement is an enzymatic cascade that results in the release of pro-inflammatory anaphylatoxins, C3b deposition and the assembly of the membrane attack complex (MAC), which results in cell lysis. Cells express complement regulatory proteins or inhibitors to protect themselves from bystander attack by complement. Expression of the complement-regulatory proteins CD55, CD46 and CD59 are deregulated in cancer with tumors showing loss of one or more inhibitors and strong overexpression of others. This results in tumors that are resistant to attack by complement and is a major limitation in the use of monoclonal antibodies as monotherapies. However, tumor sensitivity to complement can be restored by co-administration of antibodies that bind to the functional domains of complement-regulatory proteins. Overexpression of complement-regulatory proteins on tumors also makes them potential targets for cancer vaccines. However, these vaccines have to be carefully designed to induce immune responses that recognize inhibitors overexpressed on tumors and that do not detect the levels expressed by normal cells. A human anti-idiotypic antibody that mimics CD55 has been used successfully in over 200 colorectal cancer and osteosarcoma patients. 70% Of patients show CD55-specific immune responses with no associated toxicity. Similar vaccines targeting CD46 and CD59 would eliminate any cell overexpressing a complement inhibitor. Any remaining tumor cell or any tumor cell that loses complement-regulatory proteins in response to therapy would become highly susceptible to in situ complement deposition. In summary, targeting complement-regulatory proteins is a very attractive approach to tumor therapy, although great care must be taken in preventing normal tissue recognition as this could lead to uncontrolled complement deposition and massive cell lysis.
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Affiliation(s)
- L G Durrant
- Academic Unit of Clinical Oncology, City Hospital, Nottingham, UK.
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33
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Lin HH, Stacey M, Saxby C, Knott V, Chaudhry Y, Evans D, Gordon S, McKnight AJ, Handford P, Lea S. Molecular analysis of the epidermal growth factor-like short consensus repeat domain-mediated protein-protein interactions: dissection of the CD97-CD55 complex. J Biol Chem 2001; 276:24160-9. [PMID: 11297558 DOI: 10.1074/jbc.m101770200] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epidermal growth factor-like (EGF) and short consensus repeat (SCR) domains are commonly found in cell surface and soluble proteins that mediate specific protein-protein recognition events. Unlike the immunoglobulin (Ig) superfamily, very little is known about the general properties of intermolecular interactions encoded by these common modules, and in particular, how specificity of binding is achieved. We have dissected the binding of CD97 (a member of the EGF-TM7 family) to the complement regulator CD55, two cell surface modular proteins that contain EGF and SCR domains, respectively. We demonstrate that the interaction is mediated solely by these domains and is characterized by a low affinity (86 microm) and rapid off-rate (at least 0.6 s(-1)). The interaction is Ca(2+) -dependent but is unaffected by glycosylation of the EGF domains. Using biotinylated multimerized peptides in cell binding assays and surface plasmon resonance, we show that a CD97-related EGF-TM7 molecule (termed EMR2), differing by only three amino acids within the EGF domains, binds CD55 with a K(D) at least an order of magnitude weaker than that of CD97. These results suggest that low affinity cell-cell interactions may be a general feature of highly expressed cell surface proteins and that specificity of SCR-EGF binding can be finely tuned by a small number of amino acid changes on the EGF module surface.
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Affiliation(s)
- H H Lin
- Sir William Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
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34
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Abstract
In this review we summarise more than 10 years of biophysical exploration into the structural biology of the regulators of complement activation (RCA). The five human proteins responsible for regulation of the early events of complement are homologous and are composed largely from building blocks called "complement control protein (CCP) modules". Unlike most multiple domain proteins they do not contain any of the other widely occurring module types. This apparent simplicity of RCA structure, however, is belied by their sophistication of function. In fact, the structures of the individual CCP modules exhibit wide variations on a common theme while the extent and nature of intermodular connections is diverse. Some neighbouring modules within a protein stabilise each other and some co-operate to form specific binding surfaces. The degree of true "modularity" of CCPs is open to debate. The study of RCA proteins clearly illustrates the value of combining complementary structural biology techniques. The results could have implications for folding, evolution, flexibility and structure-function relationships of other molecules in the large, diverse and little understood category of multiple domain proteins.
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Affiliation(s)
- M D Kirkitadze
- Center for Neurological Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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35
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Kuttner-Kondo L, Subramanian VB, Atkinson JP, Yu J, Medof ME. Conservation in decay accelerating factor (DAF) structure among primates. Dev Comp Immunol 2000; 24:815-827. [PMID: 10906393 DOI: 10.1016/s0145-305x(00)00026-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The decay accelerating factor (DAF, CD55) protects self cells from activation of autologous complement on their surfaces. It functions to disable the C3 convertases, the central amplification enzymes of the cascade. Its active site(s) are contained within four approximately 60 amino acid long units, termed complement control protein repeats (CCPs), which are suspended above the cell surface on a 68 amino acid long serine/threonine (S/T)-rich cushion that derives from three exons. We previously proposed a molecular model of human DAF's four CCPs in which certain amino acids were postulated to be recognition sites for the interaction between DAF and the C3 convertases. In the current study, we characterized DAF in five non-human primates: the great apes, gorilla and common chimpanzee, and the Old World monkeys: hamadryas baboon, Rhesus macaque, and patas monkey. Amino acid homology to human DAF was approximately 98% for the two great apes and 83% for the three Old World monkeys. The above cited putative ligand interactive residues were found to be fully conserved in all of the non-human primates, although there were amino acid changes outside of these areas. In the chimpanzee, alternative splicing of the S/T region was found potentially to be the source of multiple protein isoforms in erythrocytes, whereas in the patas monkey, similar alternative splicing was observed but only one protein band was seen. Interestingly, a Rhesus macaque was found to exhibit a phenomenon paralleling the human Cromer Dr(a-) blood group, in which a 44-base pair deletion in CCP3 leads to a frameshift and early STOP codon.
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Affiliation(s)
- L Kuttner-Kondo
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106, USA
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36
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Abstract
The human anti-idiotypic antibody 105AD7 was isolated from a colorectal cancer patient receiving the anti-tumor antibody 791T/36 for radioimmuno-scintigraphy of liver metastases. We have mapped the binding site of 791T/36 to the first two small consensus repeat (SCR) domains of the complement regulatory protein (CD55) that is overexpressed by a wide range of solid tumors. Cloning of both antigen and anti-idiotype has identified the molecular basis of their mimicry. Amino acid homology has been identified between three complementarity-determining regions of 105AD7 and three regions of CD55 within the first two SCR domains. 791T/36 and anti-anti-idiotypic (Ab3) polyclonal antibodies raised against 105AD7 showed specific binding to these peptides. The antibodies were also found to bind synergistically to combinations of these peptides, indicating cooperativity between the peptides in stabilizing antibody binding. This also implies that the contact face on both CD55 antigen and 105AD7 is generated by the cooperation of several peptides positioned on two domains in each protein. Thus a human monoclonal anti-idiotypic antibody generated by a cancer patient is able to show both amino acid and structural homology with the complement regulatory protein CD55. These findings help identify the mechanism by which a human anti-idiotypic antibody is able to mimic a tumor-associated antigen and stimulate anti-tumor B and T cell responses.
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MESH Headings
- Adenocarcinoma/diagnostic imaging
- Adenocarcinoma/immunology
- Adenocarcinoma/secondary
- Adenocarcinoma/therapy
- Adjuvants, Immunologic/chemistry
- Adjuvants, Immunologic/therapeutic use
- Amino Acid Sequence
- Animals
- Antibodies, Anti-Idiotypic/chemistry
- Antibodies, Anti-Idiotypic/genetics
- Antibodies, Anti-Idiotypic/therapeutic use
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/immunology
- Antibodies, Neoplasm/biosynthesis
- Antibodies, Neoplasm/immunology
- Antigen-Antibody Reactions
- Antigens, CD/chemistry
- Antigens, Neoplasm/chemistry
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/immunology
- Binding Sites, Antibody
- CD55 Antigens/chemistry
- CD55 Antigens/genetics
- CD55 Antigens/immunology
- CHO Cells
- Cloning, Molecular
- Colorectal Neoplasms/immunology
- Colorectal Neoplasms/therapy
- Cricetinae
- Genes, Immunoglobulin
- Humans
- Immune Sera/immunology
- Immunity, Cellular
- Immunoglobulin Variable Region/genetics
- Liver Neoplasms/diagnostic imaging
- Liver Neoplasms/secondary
- Membrane Cofactor Protein
- Membrane Glycoproteins/chemistry
- Mice
- Mice, Inbred BALB C
- Models, Molecular
- Molecular Mimicry
- Molecular Sequence Data
- Peptide Fragments/chemistry
- Protein Conformation
- Protein Structure, Tertiary
- Radioimmunodetection
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/immunology
- Sequence Alignment
- Sequence Homology, Amino Acid
- Transfection
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Affiliation(s)
- L Spendlove
- CRC Academic Unit of Clinical Oncology, University of Nottingham, City Hospital, GB.
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37
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Pérez de la Lastra JM, Harris CL, Hinchliffe SJ, Holt DS, Rushmere NK, Morgan BP. Pigs express multiple forms of decay-accelerating factor (CD55), all of which contain only three short consensus repeats. J Immunol 2000; 165:2563-73. [PMID: 10946283 DOI: 10.4049/jimmunol.165.5.2563] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We report the cloning of cDNAs encoding multiple isoforms of the pig analogue of human decay-accelerating factor (DAF; CD55). Screening of a pig muscle cDNA library using a human DAF probe identified a single clone that encoded a DAF-like molecule comprising three short consensus repeats (SCR) homologous with the amino-terminal three SCR in human DAF, a serine/threonine-rich (ST) region, and sequence compatible with a transmembrane domain and cytoplasmic tail. Northern blot and RT-PCR analysis showed that pig DAF was expressed in a wide range of tissues. Additional isoforms of DAF were sought using RT-PCR and 3'-rapid amplification of cDNA ends followed by sequencing. Isoforms containing a GPI anchor and with differing lengths of ST region were identified; no isoform containing a fourth SCR was found. Cloning of the GPI-anchored isoform from granulocytes confirmed that it was identical with the original transmembrane isoform through the three SCR and first portion of ST and was derived from a frame shift caused by splicing out 176 bp of sequence. A panel of mAbs was generated and used to analyze the distribution and anchoring of pig DAF in circulating cells. Pig DAF was expressed on all circulating cells and was transmembrane anchored on erythrocytes, but completely or partially GPI anchored on granulocytes and mononuclear cells. The transmembrane isoform of pig DAF was expressed on Chinese hamster ovary cells and was shown to affect regulatory activity for the classical pathway of human complement, but was only marginally active against pig serum.
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Affiliation(s)
- J M Pérez de la Lastra
- Complement Biology Group, Department of Medical Biochemistry, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom
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38
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Abstract
The decay-accelerating factor (DAF) contains four complement control protein repeats (CCPs) with a single N-linked glycan positioned between CCPs 1 and 2. In previous studies we found that the classical pathway regulatory activity of DAF resides in CCPs 2 and 3 while its alternative pathway regulatory activity resides in CCPs 2, 3 and 4. Molecular modelling of the protein predicted that a positively charged surface area on CCPs 2 and 3 (including KKK125-127) and nearby exposed hydrophobic residues (L147F148) on CCP3 may function as ligand-binding sites. To assess the roles of the N-linked glycan and the above two sets of amino acids in the function of DAF, we mutated N61 to Q, KKK125-127 to TTT and L147F148 to SS. Following expression of the mutated cDNAs in Chinese hamster ovary cells, the glycosylphosphatidylinositol (GPI)-anchored mutant proteins were affinity purified and their functions were assessed. In initial assays, the proteins were incorporated into sheep and rabbit erythrocytes and the effects of the mutations on regulation of classical and alternative C3 convertase activity were quantified by measuring C3b deposition. Since DAF also functions on C5 convertases, comparative haemolytic assays of cells bearing each mutant protein were performed. Finally, to establish if spatial orientation between DAF and the convertases on the cell surface played any role in the observed effects, fluid-phase C3a generation assays were performed. All three assays gave equivalent results and showed that the N-linked glycan of DAF is not involved in its regulatory function; that L147F148 in a hydrophobic area of CCP3 is essential in both classical and alternative pathway C3 convertase regulation; and that KKK125-127 in the positively charged pocket between CCPs 2 and 3 is necessary for the regulatory activity of DAF on the alternative pathway C3 convertase but plays a lesser role in its activity on the classical pathway enzyme.
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Affiliation(s)
- W G Brodbeck
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
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39
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Hourcade D, Liszewski MK, Krych-Goldberg M, Atkinson JP. Functional domains, structural variations and pathogen interactions of MCP, DAF and CR1. Immunopharmacology 2000; 49:103-16. [PMID: 10904110 DOI: 10.1016/s0162-3109(00)80296-9] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The Regulators of Complement Activation (RCA) are a fascinating group of proteins that play important roles in innate and acquired immunity. In this review, we examine structure-function aspects of three membrane-bound RCA proteins and discuss the unique impact of their genetic organization on their evolution.
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Affiliation(s)
- D Hourcade
- Department of Medicine, Division of Rheumatology, Washington University School of Medicine, Saint Louis, MO 63110, USA
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40
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Ohta R, Imai M, Fukuoka Y, Miwa T, Okada N, Okada H. Characterization of mouse DAF on transfectant cells using monoclonal antibodies which recognize different epitopes. Microbiol Immunol 1999; 43:1045-56. [PMID: 10609614 DOI: 10.1111/j.1348-0421.1999.tb01234.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Several membrane proteins prevent host cells from homologous complement attack. In humans, one such protein, decay-accelerating factor (DAF), exists as two isoforms, a GPI anchored form and a secreted form, which are generated by alternative splicing. DAF in mouse is also expressed as two isoforms, a GPI anchored form (GPI-DAF) and a transmembrane form (TM-DAF), which are produced from two separate genes. In this study, we transfected cDNA of mouse GPI-DAF or TM-DAF into Chinese hamster ovary (CHO) cells. Both isoforms of DAF on CHO cells were shown to regulate mouse complement C3 deposition mediated by the classical and alternative pathways and the inhibitory activity of both isoforms was species restricted. The two mouse DAF isoforms were effective against rat complement but not against human and guinea pig complement. Furthermore, we produced hamster mAbs to mouse DAF using GPI-DAF transfectant cells and established seven unique mAbs (RIKO-1-7). Western blotting analysis using RIKO-3, which reacts with both GPI-DAF and TM-DAF, and RIKO-4, which is an anti-GPI-DAF specific mAb, indicated that GPI-DAF was expressed on erythrocytes, spleen and testis, and that TM-DAF was expressed only in testis.
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Affiliation(s)
- R Ohta
- Department of Molecular Biology, Nagoya City University School of Medicine, Aichi, Japan
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41
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Powell RM, Ward T, Goodfellow I, Almond JW, Evans DJ. Mapping the binding domains on decay accelerating factor (DAF) for haemagglutinating enteroviruses: implications for the evolution of a DAF-binding phenotype. J Gen Virol 1999; 80 ( Pt 12):3145-3152. [PMID: 10567645 DOI: 10.1099/0022-1317-80-12-3145] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Decay accelerating factor (DAF) functions as a cell attachment receptor for a wide range of human enteroviruses, the interaction accounting for the haemagglutination phenotype exhibited by many members of this family. Haemagglutination inhibition assays using purified truncated soluble DAF (sDAF) receptors and short consensus repeat (SCR) domain-specific antibodies have been used to determine the domain(s) of DAF to which the viruses bind. Further sDAF-mediated virus neutralization and biosensor analysis have been used to confirm the virus-binding domains of DAF. Of the four distinct clusters of human enteroviruses, three contain representatives that bind DAF. The majority of DAF-binding enteroviruses occupy the 'CBV-like' cluster, and require SCR domains 2-4 for DAF binding. In contrast, the DAF-binding representatives of the 'ENV70-like' and 'PV-like' clusters require SCR1 for DAF interaction. These studies confirm that DAF binding is a widespread characteristic amongst phylogenetically divergent clusters within the enteroviruses and suggest that the ability to bind DAF may have evolved more than once within this group of viruses.
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Affiliation(s)
- Robert M Powell
- School of Animal and Microbial Sciences, The University of Reading, Whiteknights, PO Box 228, Reading RG6 5AJ, UK2
| | - Trevor Ward
- School of Animal and Microbial Sciences, The University of Reading, Whiteknights, PO Box 228, Reading RG6 5AJ, UK2
- Division of Virology, Institute of Biomedical and Life Sciences, University of Glasgow, Church Street, Glasgow G11 5JR, UK1
| | - Ian Goodfellow
- Division of Virology, Institute of Biomedical and Life Sciences, University of Glasgow, Church Street, Glasgow G11 5JR, UK1
| | - Jeffrey W Almond
- School of Animal and Microbial Sciences, The University of Reading, Whiteknights, PO Box 228, Reading RG6 5AJ, UK2
| | - David J Evans
- Division of Virology, Institute of Biomedical and Life Sciences, University of Glasgow, Church Street, Glasgow G11 5JR, UK1
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42
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Lea S, Powell R, Evans D. Crystallization and preliminary X-ray diffraction analysis of a biologically active fragment of CD55. Acta Crystallogr D Biol Crystallogr 1999; 55:1198-200. [PMID: 10329784 DOI: 10.1107/s0907444999001638] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Crystals have been grown of two of the domains of CD55. This is the first report of crystallization of a short consensus repeat (SCR) domain containing protein. CD55 is a widely expressed polymorphic glycoprotein, which functions as a complement regulator by inhibiting assembly and promoting destruction of C3 and C5 convertases. As a key regulator of complement, CD55 is implicated in the hyperacute rejection of xenografts from pigs into primates. It is also commonly hijacked as a receptor by viruses (e.g. medically important echoviruses and coxsackieviruses) and bacterial pathogens (e.g. certain pathogenic strains of Escherichia coli). Here, crystallization of a virus-binding fragment expressed in yeast, consisting of two of the four extracellular SCR domains of CD55, is reported. The recombinant domains have been crystallized in 30% polyethylene glycol (PEG), 0.2 M sodium acetate, 0.1 M sodium acetate trihydrate pH 4.6 using the sitting-drop vapour-diffusion method. Two crystal forms are observed (orthorhombic and monoclinic) and a native data set to 1.65 A resolution has been collected from the monoclinic form at the Synchrotron Radiation Source, Daresbury, UK.
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Affiliation(s)
- S Lea
- Laboratory of Molecular Biophysics, Rex Richards Building, South Parks Road, Oxford OX1 3QU, England.
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43
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Hinchliffe SJ, Spiller OB, Rushmere NK, Morgan BP. Molecular cloning and functional characterization of the rat analogue of human decay-accelerating factor (CD55). J Immunol 1998; 161:5695-703. [PMID: 9820551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
We report here the cloning of cDNAs encoding two forms of the rat analogue of human decay-accelerating factor (DAF; CD55). Screening of a rat kidney cDNA library using a mouse DAF probe identified a partial cDNA encoding the 3' end of rat DAF. The 5' end of the cDNA was cloned using the rapid amplification of cDNA ends (RACE) technique. A second form of rat DAF was identified using 3'RACE. Cloning and sequencing of full length cDNAs for both forms showed that they were identical up to nucleotide 1143 except for a 51-bp insert in the ST-rich region of the second form. After nucleotide 1143, the two sequences diverged; the cDNA cloned from the library encoded a unique 112-amino acid "tail," whereas the second form, identified by 3'RACE, encoded an 18-amino acid hydrophobic stretch, which was predicted to be a glycosylphosphatidylinositol (GPI) anchor addition signal. Expression in the NIH-3T3 mouse fibroblast cell line confirmed that the short tail did encode a GPI-addition signal, whereas the longer tail caused the protein to be secreted. Northern blot analysis identified two distinct transcripts for the GPI form, as well as a variability in expression levels of the different transcripts in the panel of tissues screened. Southern blot analysis showed that both the GPI and secreted forms of rat DAF were expressed in a wide range of tissues. The GPI-linked form of rat DAF stably expressed in a murine fibroblast cell line reduced C3 deposition and conferred protection from lysis by rat serum.
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Affiliation(s)
- S J Hinchliffe
- Department of Medical Biochemistry, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom
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44
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Abstract
Decay-accelerating factor (DAF) mediates cellular attachment for many human picornaviruses. In most cases, viral binding to DAF is itself insufficient to permit cell infectivity, with a second, functional internalization receptor being required to facilitate this process. Previously, we postulated that the role of DAF in enterovirus cell infection is as a sequestration receptor, maintaining a reservoir of bound virus in an infectious state, awaiting interaction with functional internalization receptors. Many of these functional receptors possess the capacity to induce relatively rapid changes in capsid conformations, resulting in the formation of altered particles (A-type particles). In this report, we show that antibody-cross-linked DAF, in contrast to endogenous surface-expressed forms, can act as a functional virus receptor to mediate coxsackie A21 virus (CAV21) lytic cell infection. In contrast to the situation with ICAM-1-mediated CAV21 infection, in which high levels of A-type particles are formed, cross-linked DAF-induced CAV21 replication occurs in the absence of detectable A-particle formation.
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Affiliation(s)
- D R Shafren
- Department of Microbiology, Faculty of Medicine, The University of Newcastle, Newcastle New South Wales 2300, Australia.
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45
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Abstract
Enterovirus 70 (EV70), like several other human enteroviruses, can utilize decay-accelerating factor (DAF [CD55]) as an attachment protein. Using chimeric molecules composed of different combinations of the short consensus repeat domains (SCRs) of DAF and membrane cofactor protein (CD46), we show that sequences in SCR1 of DAF are essential for EV70 binding. Of the human enteroviruses that can bind to DAF, only EV70 and coxsackievirus A21 require sequences in SCR1 for this interaction.
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Affiliation(s)
- T M Karnauchow
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada K1H 8M5
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46
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Solomon KR, Mallory MA, Finberg RW. Determination of the non-ionic detergent insolubility and phosphoprotein associations of glycosylphosphatidylinositol-anchored proteins expressed on T cells. Biochem J 1998; 334 ( Pt 2):325-33. [PMID: 9716490 PMCID: PMC1219694 DOI: 10.1042/bj3340325] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins are poorly solublized in non-ionic detergents such as Triton X-100 and Nonidet P40, but are easily solublized by detergents with high critical micelle concentrations such as octylglucoside. This solubility profile has been suggested to be due to the localization of GPI-anchored proteins to lipid microdomains rich in cholesterol and sphingolipids. Additionally, GPI-anchored proteins expressed on haemopoietic cells have been shown to associate with src-family tyrosine kinases and heterotrimeric G proteins. Despite these observations, the non-ionic detergent insolubility of GPI-anchored proteins on haemopoietic cells has not been quantified nor has a relationship between the non-ionic detergent insolubility of these proteins and their association with signal-transduction molecules been identified. Here we show that GPI-anchored proteins found on T-cell tumours and activated T cells, although significantly more insoluble then transmembrane proteins, are not uniform in their detergent insolubility. Whereas CD59 was between 4% and 13% soluble, CD48 was between 13% and 25% soluble, CD55 was between 20% and 30% soluble, and CD109 was between 34% and 75% soluble. The ability of these GPI-anchored proteins to associate with phosphoproteins was correlated with their detergent insolubility: the more detergent-insoluble that a GPI-anchored protein was, the greater the level of phosphoprotein associations. These experiments reveal a relationship between non-ionic detergent insolubility and association with signal-transduction molecules and suggest a cause-and-effect relationship between these two properties. In total, these experiments support the hypothesis that the association of GPI-anchored proteins with signalling molecules is due to their sorting to lipid microdomains.
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Affiliation(s)
- K R Solomon
- Infectious Disease Unit, Dana-Farber Cancer Institute, 44 Binney St., Boston, MA 02115, USA
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47
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Abstract
There is some discussion as to whether glycosyl-phosphatidylinositol(GPI)-anchored proteins occur in microdomains in the cell membrane. These putative microdomains have been implicated in processes such as sorting in polarized cells and signal transduction. Complexes enriched in GPI-anchored proteins, cholesterol and glycosphingolipids have been isolated from cell membranes by using non-ionic detergents: these complexes were thought to represent a clustered arrangement of GPI-anchored proteins. However, results obtained when clustering of GPI-anchored proteins induced by antibodies or by detergents was prevented support the idea of a dispersed surface distribution of GPI-anchored proteins at steady state. Here we use chemical crosslinking to show that membrane microdomains of a GPI-anchored protein exist at the surface in living cells. This clustering is specific for the GPI-anchored form, as two transmembrane forms bearing the same ectodomain do not form oligomers. Depletion of membrane cholesterol causes the clustering of GPI-anchored proteins to break up, whereas treatment of cells with detergent substantially increases the size of the complexes. We find that in living cells these GPI-anchored proteins reside in microdomains consisting of at least 15 molecules, which are much smaller than those seen after detergent extraction.
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Affiliation(s)
- T Friedrichson
- Department of Cell Biology, Max Delbrück Centre for Molecular Medicine, Berlin-Buch, Germany
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48
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Abstract
CD97 is an activation-induced antigen on leukocytes which belongs to a new group of seven-span transmembrane (7-TM) molecules, designated EGF-TM7 family. Family members, including EMR1 and F4/80, are characterized by an extended extracellular region with several N-terminal epidermal growth factor-like (EGF) domains. Alternative splicing of CD97 results in isoforms possessing either three (EGF1, 2, 5), four (EGF1, 2, 3, 5) or five EGF domains (EGF1, 2, 3, 4, 5). We recently identified decay accelerating factor (DAF, CD55), a regulatory protein of the complement cascade, as a cellular ligand of the smallest isoform. Employing mutants of CD97(EGF1, 2, 5) in which the EGF domains have been systematically deleted, we here demonstrate the necessity of at least three tandemly linked EGF domains for the interaction with CD55. Consistent with the involvement of different EGF domains, monoclonal antibodies directed against the first EGF domain as well as the removal of Ca2+, for which binding sites exist in the second and fifth EGF domain, blocked binding to CD55. Compared to CD97(EGF1, 2 ,5) the larger isoforms CD97(EGF1, 2, 3, 5) and CD97(EGF1, 2, 3, 4, 5) have a significantly lower affinity for CD55. Thus, alternative splicing may regulate the ligand specificity of CD97 and probably other members of the EGF-TM7 family.
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Affiliation(s)
- J Hamann
- Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, University of Amsterdam.
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49
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Abstract
BACKGROUND Cromer blood group antigens are located on decay-accelerating factor (DAF, CD55), which contains four short consensus repeats (SCRs). Cromer system antibodies may be of clinical significance in blood transfusion. STUDY DESIGN AND METHODS Soluble recombinant DAF (srDAF) constructs, consisting of all four SCRs or of only two SCRs, were expressed in the yeast Pichia pastoris. They are used in hemagglutination-inhibition tests with Cromer system antibodies and with DAF-specific monoclonal antibodies. RESULTS The srDAF inhibited hemagglutination by all Cromer system alloantibodies in undiluted serum. Antibodies to antigens of other blood group systems were not inhibited by the srDAF. Hemagglutination-inhibition tests with domain-deleted srDAF showed that UMC is on SCR-4 and confirmed that Tca, TcaTcb, and WESb are on SCR-1; Dra is on SCR-3; and Cra is on SCR-4. CONCLUSIONS Hemagglutination inhibition with srDAF is useful in the recognition of antibodies that belong to the Cromer blood group system and facilitates pretransfusion testing. This use of domain-deleted srDAF provides an easy method of determining epitope location on DAF and is an aid to more precise identification of Cromer system antibodies.
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Affiliation(s)
- G L Daniels
- Bristol Institute for Transfusion Sciences, United Kingdom
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Wang G, Nonaka M, He C, Okada N, Nakashima I, Okada H. Functional differences among multiple isoforms of guinea pig decay-accelerating factor. J Immunol 1998; 160:3014-22. [PMID: 9510206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Decay-accelerating factor (DAF, CD55) is a membrane inhibitor that protects host cells from the autologous C-mediated attack. The guinea pig homologue of DAF consists of multiple isoforms generated by alternative splicing from a single copy gene. These isoforms are mainly comprised of a glycosylphosphatidylinositol (GPI)-anchored form and a transmembrane form (TM) that is not present in human DAF. Both forms occur in at least three variations that differ in the length of the Ser/Thr-rich region (termed ST-a, ST-ab, and ST-abc). We have transfected cDNAs of the six major isoforms into Chinese hamster ovary cells, and their functional differences were evaluated in inhibition of C-mediated cytolysis and C3 deposition, using the transfectants expressing DAF at the same level on cell membranes. The degree of inhibition in both the classical and alternative pathways differed according to the length of the ST region in the order of abc > ab > a in both GPI and TM forms. When GPI and TM forms were compared, those with the ab or abc variation exhibited almost the same activity, whereas a-TM was less efficient than a-GPI. Although several isoforms are expressed constitutively in most of tissues, spermatozoa preferentially express the abc-GPI isoform, suggesting that this isoform offers effective protection to spermatozoa in the female genital tract.
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Affiliation(s)
- G Wang
- Department of Immunology, Nagoya University School of Medicine, Japan
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