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Efimov S, Karataeva F, Aganov A, Berger S, Klochkov V. Spatial structure of cyclosporin A and insight into its flexibility. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.11.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Galat A, Bua J. Molecular aspects of cyclophilins mediating therapeutic actions of their ligands. Cell Mol Life Sci 2010; 67:3467-88. [PMID: 20602248 PMCID: PMC11115621 DOI: 10.1007/s00018-010-0437-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/04/2010] [Accepted: 06/10/2010] [Indexed: 12/14/2022]
Abstract
Cyclosporine A (CsA) is an immunosuppressive cyclic peptide that binds with a high affinity to 18 kDa human cyclophilin-A (hCyPA). CsA and its several natural derivatives have some pharmacological potential in treatment of diverse immune disorders. More than 20 paralogues of CyPA are expressed in the human body while expression levels and functions of numerous ORFs encoding cyclophilin-like sequences remain unknown. Certain derivatives of CsA devoid of immunosuppressive activity may have some potential in treatments of Alzheimer diseases, Hepatitis C and HIV infections, amyotrophic lateral sclerosis, congenital muscular dystrophy, asthma and various parasitic infections. Here, we discuss structural and functional aspects of the human cyclophilins and their interaction with various intra-cellular targets that can be under the control of CsA or its complexes with diverse cyclophilins that are selectively expressed in different cellular compartments. Some molecular aspects of the cyclophilins expressed in parasites invading humans and causing diseases were also analyzed.
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Affiliation(s)
- Andrzej Galat
- SIMOPRO, Institute de Biologie et de Technologies de Saclay, DSV/CEA, Bat. 152, CE-Saclay, Gif-sur-Yvette Cedex, France.
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Malesević M, Kühling J, Erdmann F, Balsley MA, Bukrinsky MI, Constant SL, Fischer G. A cyclosporin derivative discriminates between extracellular and intracellular cyclophilins. Angew Chem Int Ed Engl 2010; 49:213-5. [PMID: 19957254 DOI: 10.1002/anie.200904529] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Miroslav Malesević
- Max-Planck-Forschungsstelle für Enzymologie der Proteinfaltung, Weinbergweg 22, 06120 Halle, Germany
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Malešević M, Kühling J, Erdmann F, Balsley M, Bukrinsky M, Constant S, Fischer G. Differenzielle Hemmung extra- und intrazellulärer Cyclophiline durch Cyclosporinderivate. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200904529] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kanoh N, Honda K, Simizu S, Muroi M, Osada H. Photo-cross-linked small-molecule affinity matrix for facilitating forward and reverse chemical genetics. Angew Chem Int Ed Engl 2006; 44:3559-62. [PMID: 15880755 DOI: 10.1002/anie.200462370] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Naoki Kanoh
- Antibiotics Laboratory, Discovery Research Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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6
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van den Berg FA, Baken KA, Vermeulen JP, Gremmer ER, van Steeg H, van Loveren H. Use of the local lymph node assay in assessment of immune function. Toxicology 2005; 211:107-14. [PMID: 15863253 DOI: 10.1016/j.tox.2005.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Revised: 03/03/2005] [Accepted: 03/03/2005] [Indexed: 10/25/2022]
Abstract
The murine local lymph node assay (LLNA) was originally developed as a predictive test method for the identification of chemicals with sensitizing potential. In this study we demonstrated that an adapted LLNA can also be used as an immune function assay by studying the effects of orally administered immunomodulating compounds on the T-cell-dependent immune response induced by the contact sensitizer 2,4-dinitrochlorobenzene (DNCB). C57Bl/6 mice were treated with the immunotoxic compounds cyclosporin A (CsA), bis(tri-n-butyltin)oxide (TBTO) or benzo[a]pyrene, (B[a]P). Subsequently, cell proliferation and interferon-gamma (IFN-gamma) and interleukin (IL)-4 release were determined in the auricular lymph nodes (LNs) after DNCB application on both ears. Immunosuppression induced by CsA, TBTO and B[a]P was clearly detectable in this application of the LLNA. Cytokine release measurements proved valuable to confirm the results of the cell proliferation assay and to obtain an indication of the effect on Th1/Th2 balance. We believe to have demonstrated the applicability of an adapted LLNA as an immune function assay in the mouse.
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Affiliation(s)
- Femke A van den Berg
- National Institute of Public Health and the Environment (RIVM), Department of Toxicology, Pathology and Genetics, Postbus 1, 3720 BA Bilthoven, The Netherlands.
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7
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Kanoh N, Honda K, Simizu S, Muroi M, Osada H. Photo-Cross-Linked Small-Molecule Affinity Matrix for Facilitating Forward and Reverse Chemical Genetics. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200462370] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Manzoni C, Duranti M, Eberini I, Scharnag H, März W, Castiglioni S, Lovati MR. Subcellular localization of soybean 7S globulin in HepG2 cells and LDL receptor up-regulation by its alpha' constituent subunit. J Nutr 2003; 133:2149-55. [PMID: 12840170 DOI: 10.1093/jn/133.7.2149] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The aims of this work were to monitor the subcellular localization of soybean 7S globulin in HepG2 cells and determine its interaction with cell protein components, by using laser-induced fluorescence capillary electrophoresis (LIF-CE). Furthermore, we evaluated in the same cell line the involvement of the alpha' constituent subunit from 7S globulin in the modulation of LDL catabolism. The results indicated a main fluorescein isothiocyanate-tagged 7S globulin (FITC-7S) component in the cytosolic fraction, that was not present in the nuclear compartment. The electrophoretic mobility of this tagged component suggested either a dissociation of the 7S oligomer or its partial intracellular degradation. Interactions of soybean 7S globulin with FITC-thioredoxin 1 and FITC-cyclophilin B, HepG2 cell membrane proteins, were demonstrated in in vitro assays. In a separate experiment with HepG2 cells, the ability of the alpha' subunit purified from soybean 7S globulin to modulate the activity of the LDL receptors was evaluated by tracking the uptake and degradation of labeled LDL. The up-regulation of LDL receptors by the alpha' subunit, as further confirmed by a LDL receptor promoter assay, was significantly greater than that found in the control cells. In conclusion, this study, while confirming our previous indirect evidence of the key role of alpha' subunit on the cell cholesterol homeostasis, reveals a potentially interesting association of soybean 7S globulin with proteins, such as thioredoxin 1 and cyclophilin B, that are involved in cell protection against oxidative stress.
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Affiliation(s)
- Cristina Manzoni
- Department of Pharmacological Sciences, University of Milan, 20133 Milan, Italy
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9
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Robson D. Review of the properties and mechanisms of action of cyclosporine with an emphasis on dermatological therapy in dogs, cats and people. Vet Rec 2003; 152:768-72. [PMID: 12846287 DOI: 10.1136/vr.152.25.768] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Cyclosporine is being increasingly used in veterinary medicine. It is a potent suppressor of T cell induction and proliferation, and has a wide variety of anti-inflammatory and antiproliferative effects, downregulating effects on antigen presentation, and variable effects on parasites. This paper reviews its properties and mechanisms of action with particular reference to its use in the treatment of dermatological conditions in dogs, cats and people.
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Affiliation(s)
- D Robson
- Melbourne Veterinary Referral Centre, 70 Blackburn Road, Glen Waverley, Victoria 3150, Australia
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Rühlmann A, Nordheim A. Effects of the immunosuppressive drugs CsA and FK506 on intracellular signalling and gene regulation. Immunobiology 1997; 198:192-206. [PMID: 9442391 DOI: 10.1016/s0171-2985(97)80040-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The isolation of Cyclosporin A (CsA) from cultures of the fungus Tolypocladium inflatum and its subsequent elucidation of immunosuppressive properties by Borel et al. (1) was of great clinical consequence. In the early 80s CsA was introduced in the field of organ transplantation resulting in extraordinary improvements of graft survival. CsA has become a first choice drug for patients with allograft organs. The discovery of FK506 by Kino et al. (2) as a novel immuno-suppressant and its introduction into clinics in 1989 (3) extended the available regimen for immunosuppressive therapy. Yet despite their advantages both CsA and FK506 display unwanted side effects and a possible preference of one drug over another remains controversial (4, 5). Although identification of the involvement of the transcription factor NF-AT was an important step forward (6), it has become clear that immunosuppressant action is more complex. CsA and FK506 selectively interact with certain cellular signal transduction pathways. This review briefly describes these effects on signal transduction. We further concentrate on the major known effect of these immunosuppressants, namely the inhibition of the PP2B phosphatase calcineurin. In addition we provide a compilation of effects of CsA and FK506 on gene expression at the level of transcription.
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Affiliation(s)
- A Rühlmann
- Hannover Medical School, Institute for Molecular Biology, Germany.
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Allain F, Denys A, Spik G. Cyclophilin B mediates cyclosporin A incorporation in human blood T-lymphocytes through the specific binding of complexed drug to the cell surface. Biochem J 1996; 317 ( Pt 2):565-70. [PMID: 8713086 PMCID: PMC1217523 DOI: 10.1042/bj3170565] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein located within intracellular vesicles and released in biological fluids. We recently reported the specific binding of this protein to T-cell surface receptor which is internalized even in the presence of CsA. These results suggest that CyPB might target the drug to lymphocytes and consequently modify its activity. To verify this hypothesis, we have first investigated the binding capacity and internalization of the CsA-CyPB complex in human peripheral blood T-lymphocytes and secondly compared the inhibitory effect of both free and CyPB-complexed CsA on the CD3-induced activation and proliferation of T-cells. Here, we present evidence that both the CsA-CyPB complex and free CyPB bind to the T-lymphocyte surface, with similar values of Kd and number of sites. At 37 degrees C, the complex is internalized but, in contrast to the protein, the drug is accumulated within the cell. Moreover, CyPB receptors are internalized together with the ligand and rapidly recycled to the cell surface. Finally, we demonstrate that CyPB-complexed CsA remains as efficient as uncomplexed CsA and that CyPB enhances the immunosuppressive activity of the drug. Taken together, our results support the hypothesis that surface CyPB receptors may be related to the selective and variable action of CsA, through specific binding and targeting of the CyPB-CsA complex to peripheral blood T-lymphocytes.
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Affiliation(s)
- F Allain
- Laboratoire de Chimie Biologique, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France
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12
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Abstract
This review presents the progress and some aspects achieved during recent years with cyclosporin sources, chemistry, biological activities, side effects, biosynthesis and metabolism. Although incomplete the results indicate future research trends and some white spots to be studied in the near future to afford unique insights into cell biology and to improve the search for similar and even more specific agents based on rational drug design.
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Franke EK, Luban J. Cyclophilin and gag in HIV-1 replication and pathogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1995; 374:217-28. [PMID: 7572395 DOI: 10.1007/978-1-4615-1995-9_19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- E K Franke
- Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA
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Allain F, Denys A, Spik G. Characterization of surface binding sites for cyclophilin B on a human tumor T-cell line. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)89421-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Price ER, Jin M, Lim D, Pati S, Walsh CT, McKeon FD. Cyclophilin B trafficking through the secretory pathway is altered by binding of cyclosporin A. Proc Natl Acad Sci U S A 1994; 91:3931-5. [PMID: 7909608 PMCID: PMC43696 DOI: 10.1073/pnas.91.9.3931] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Cyclophilin B is targeted to the secretory pathway via an endoplasmic reticulum signal sequence. We analyzed the localization and trafficking of endogenous and transfected cyclophilin B in mammalian cells. Cyclophilin B accumulates both in the endoplasmic reticulum and in complexes on the plasma membrane. The immunosuppressant cyclosporin A specifically mobilizes cyclophilin B from the endoplasmic reticulum, and promotes the secretion of cyclophilin B into the medium. We suggest that cyclosporin A competes with endogenous plasma membrane proteins for association with cyclophilin B in the secretory pathway. These findings argue in favor of a role for cyclophilin B as a chaperone to proteins destined for the plasma membrane, rather than solely as a proline isomerase functioning within the endoplasmic reticulum.
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Affiliation(s)
- E R Price
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
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Hacker J, Fischer G. Immunophilins: structure-function relationship and possible role in microbial pathogenicity. Mol Microbiol 1993; 10:445-56. [PMID: 7526121 DOI: 10.1111/j.1365-2958.1993.tb00917.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Immunophilins are housekeeping proteins present in a wide variety of organisms. Members of two protein superfamilies, cyclophilins (Cyps) and FK506-binding proteins (FKBPs) belong to this class of immunophilins. Despite the fact that the amino acid sequences of Cyp and FKBPs do not exhibit noticeable homology to each other, proteins of both classes are able to ligate immunosuppressive peptide derivatives. Cyps form complexes with the cyclic undercapeptide cyclosporin A and FKBPs are able to bind FK506 as well as rapamycin, both of which have a pipecolyl bond within their structure. In a ligand-bound form, immunophilins interfere with signal transduction in T cells. In addition, immunophilins have peptidyl prolyl cis-trans isomerase (PPlase) activity and are able to accelerate the rate of conformational events in proline-containing polypeptides. Microorganisms produce proteins that exhibit extensive sequence homologies to cyclophilins and FKBPs of higher organisms and which have considerable PPlase catalytic activity. While cyclophilins seem to be present in most if not all microbial species investigated, FKBPs are produced by yeasts as well as by a number of pathogenic bacteria, such as Legionella pneumophila, Chlamydia trachomatis and Neisseria meningitidis. The Mip protein of L. pneumophila is a virulence factor that plays an essential role in the ability of the bacteria to survive and multiply in phagocytic cells. Some results are summarized on the structure and putative functions of immunophilins and place special emphasis on the contribution of these polypeptides to the virulence of pathogenic microorganisms.
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Affiliation(s)
- J Hacker
- Institut für Molekulare Infektionsbiologie, Würzburg, Germany
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18
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Abstract
Two sequence-unrelated families of proteins possess peptidylproline cis-trans-isomerase activities (PPIase). PPIases are highly sequence conserved and multifunctional proteins which are present in many types of cells with a considerably divergent phylogenetic distribution. On the cellular level, PPIases occur in every compartment, both as free species and anchored to membranes. Diverse posttranslational modifications such as glycosylation, N-terminal modifications and phosphorylation constitute the additional functional features of PPIases. Folding, assembly and trafficking of proteins in the cellular milieu are regulated by PPIases. These enzymes accelerate the rate of in-vitro protein folding and they have the ability to bind proteins and act as chaperones. Some PPIases are coregulatory subunits of molecular complexes including heat-shock proteins, glucocorticoid receptors and ion channels. Secreted forms of PPIases are inflammatory and chemotactic agents for monocytes, eosinophils and basophils. The potent and clinically useful immunosuppressants CsA, FK506 or rapamycin bind with high affinities to PPIases (immunophilins). The binding criterion allows us to sort the PPIases for the following two superfamilies of proteins: the cyclophilins (CsA-binding proteins) and the FKBP (FK506/rapamycin-binding proteins). Although none of PPIases appeared to be essential for the viability of haploid yeast cells some of the immunophilin/immunosuppressant complexes are toxic both for yeast and mammalian cells. At least seven unlinked genes of cyclophilins and four unlinked genes of FKBP exist in human genomic DNA. Selected immunophilins regulate two different signalling pathways in lymphoid cells, namely the secretion of growth factors by stimulated T-cells and interleukin-2-induced T-cell proliferation. Moreover, selected FKBP mediate the cytotoxic effects of rapamycin in non-lymphoid cells. Accounts of the discovery of PPIases (immunophilins) and their functions are given in this review. A larger spectrum of proteins is analysed in relation to various signal-transduction pathways in lymphoid cells which involve immunophilins or their complexes with the immunosuppressants CsA, FK506 or rapamycin.
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Affiliation(s)
- A Galat
- Département d'Ingénierie et d'Etudes des Protéines, Centre d'Etudes de Saclay, Gif-sur-Yvette, France
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Bakker NP, Van Besouw N, Groenestein R, Jonker M, Hart LA. The anti-arthritic and immunosuppressive effects of cyclosporin A on collagen-induced arthritis in the rhesus monkey. Clin Exp Immunol 1993; 93:318-22. [PMID: 8370160 PMCID: PMC1554915 DOI: 10.1111/j.1365-2249.1993.tb08179.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The influence of cyclosporin A (CsA) on type II collagen-induced arthritis (CIA) in the rhesus monkey has been investigated. CsA was administered subcutaneously in a dose of 25 mg/kg per day during 9-18 days and additionally 12.5 mg/kg per day for 7 days. At this dosing regime no significant alterations of haematologic parameters were found, indicating that the toxicity of CsA was negligible. Administration of CsA after onset of arthritis had no beneficial effect, but when given between immunization and manifestation of clinical symptoms, CIA could be prevented completely. Moreover, these monkeys became resistant to the disease, because no arthritic activity could be observed upon a booster immunization with type II collagen (CII). The suppression of disease by CsA is reflected in reduced antibody levels to CII.
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Affiliation(s)
- N P Bakker
- Department of Chronic and Infectious Diseases, TNO Medical Biological Laboratory, Rijswijk, The Netherlands
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Zenke G, Baumann G, Wenger R, Hiestand P, Quesniaux V, Andersen E, Schreier MH. Molecular mechanisms of immunosuppression by cyclosporins. Ann N Y Acad Sci 1993; 685:330-5. [PMID: 7689806 DOI: 10.1111/j.1749-6632.1993.tb35882.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Despite the successful clinical application of the immunosuppressive drug cyclosporin A (CsA, Sandimmun), its precise mechanism of action in the process of T cell activation remains elusive. CsA binds to the high-affinity cytosolic receptor cyclophilin whose peptidyl-prolyl cis-trans isomerase activity is inhibited upon binding. The linkage of this effect with the inhibition of the T cell receptor-mediated signal transduction pathway, which leads to a suppression of lymphokine gene transcription, is still unclear. We analyzed the relationship between cyclophilin-binding and immunosuppressive activity (e.g., effect on IL-2 transcription) of cyclosporin derivatives in vitro. The results show that binding to cyclophilin is required, but not sufficient for immunosuppression. Cyclosporin analogues which completely lack immunosuppressive activity but fully retained their cyclophilin-binding capacity antagonize the immunosuppressive activity of CsA. These derivatives inhibit the isomerase activity of cyclophilin, which clearly demonstrates that inhibition of the cyclophilin isomerase activity does not lead to immunosuppression. In analogy to the other immunosuppressants of microbial origin, FK-506 and rapamycin, a specific structure of the "effector" domain of CsA, which is unrelated to the cyclophilin-binding domain, determines the biological activity. In the nucleus, CsA interferes with the DNA-binding of inducible transcription factors to their respective DNA motifs within lymphokine promoters by affecting intracellular translocation of transcription factor subunits.
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Affiliation(s)
- G Zenke
- Preclinical Research, Sandoz Pharma Ltd., Basel, Switzerland
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Tipton DA, Dabbous MK. Binding and subcellular distribution of cyclosporine in human fibroblasts. J Cell Biochem 1993; 51:345-52. [PMID: 8501136 DOI: 10.1002/jcb.240510314] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The uptake, binding, and subcellular sites of accumulation of [3H]-cyclosporine (CS) in two human gingival fibroblast strains, GN 23 and GN 54, have been examined. GN 23 responds to CS treatment with a decrease in collagenolysis, while GN 54 does not. Binding of the drug was determined using [3H]-CS concentrations ranging from 10(-5) to 10(-8) M in the absence or presence of excess unlabeled CS (1 mM). The binding of the drug to both strains was specific and reached a plateau within 10 min, remaining at that level for up to 1 h. Scatchard analysis of the specific binding of [3H]-CS to the responsive GN 23 strain revealed two dissociation constants: KD = 5 x 10(-8) M (1.2 x 10(7) sites/cell) and KD = 1.4 x 10(-6) M (2.2 x 10(8) sites/cell). GN 54, on the other hand, had only one class of low affinity binding site (KD = 0.47 x 10(-6) M [1.2 x 10(8) sites/cell]). Unlabeled CS (0.01-1 mM) inhibited the binding of [3H]-CS in a dose-dependent manner to both strains, as did the calmodulin antagonist W-7, to a lesser extent. However, W-7 inhibited CS binding much more efficiently in GN 54 than in GN 23, suggesting that calmodulin may be the predominant CS receptor in GN 54. In both strains, 70% of the drug accumulated in the crude nuclear fraction after a 1 min incubation, with very little (< or = 4%) being membrane associated, and the remainder was in the cytosol.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D A Tipton
- Dental Research Center, University of Tennessee, Memphis 38163
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Anderson SK, Gallinger S, Roder J, Frey J, Young HA, Ortaldo JR. A cyclophilin-related protein involved in the function of natural killer cells. Proc Natl Acad Sci U S A 1993; 90:542-6. [PMID: 8421688 PMCID: PMC45699 DOI: 10.1073/pnas.90.2.542] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Natural killer cells are non-major histocompatibility complex-restricted large granular lymphocytes that can recognize and destroy tumor cells without prior stimulation. A 150-kDa molecule on the surface of human natural killer cells was identified as a component of a putative tumor-recognition complex. We report here the isolation of cDNAs coding for the 150-kDa tumor-recognition molecule from human and mouse cDNA libraries. The amino terminus of the predicted protein contains a large hydrophobic region followed by a domain that is highly homologous to cyclophilin/peptidylprolyl cis-trans isomerase. The remainder of the protein is extremely hydrophilic and contains three homologous positively charged clusters. There are also three regions that contain extensive arginine- and serine-rich repeats. Comparison of the human and mouse predicted amino acid sequences revealed > 80% homology.
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Affiliation(s)
- S K Anderson
- Division of Molecular Immunology and Neurobiology, Mount Sinai Hospital Research Institute, Toronto, Ontario, Canada
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