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Botti C, Seregni E, Ferrari L, Martinetti A, Bombardieri E. Immunosuppressive Factors: Role in Cancer Development and Progression. Int J Biol Markers 2018; 13:51-69. [PMID: 9803353 DOI: 10.1177/172460089801300201] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The concept of the immunological surveillance against neoplastic cells was initially proposed by Erlich in 1909 and later elaborated by Burnet. This hypothesis states that the normal function of the immune system, in particular the cell-mediated immunity, is to recognize and destroy the transformed and proliferating tumor cells. The role of cell-mediated immunity during the first steps of tumorigenesis remains controversial. However, there is certain evidence about its importance in the progression and dissemination of cancer. The frequent immunosuppressed condition of cancer patients at tumor relapse or recurrence of secondary tumors is a clinical sign supporting this hypothesis, and many studies have demonstrated a defective immune response in patients diagnosed with advanced cancer. Several mechanisms of escape from the immune surveillance have been described, including the immunoselection of tumor antigen-negative variants, the downregulation of MHC class I expression, suppressive T cells, and the elaboration of immunosuppressive cytokines and other factors. Because of the technical difficulty of isolating the very small amounts from culture supernatants or body fluids, only a few of these substances have been characterized and studied with respect to their biological activity: transforming growth factor-β (TGF-β), the protein p15E, interleukin 10 (IL-10), prostaglandin E2 (PGE2), mucins, suppressive E-receptor (SER), immunosuppressive acidic protein (IAP), and adhesion molecules. The possibility of monitoring cancer patients by testing biochemical factors related to cancer growth led to a proposal to measure a number of these factors as tumor markers. Some of them, e.g mucins, enjoy the consensus of the oncologic community, as for some indications they can help the clinician in the management of cancer patients. Except for the class of mucins, the other above-mentioned immunosuppressive factors have not found any clinical application in the laboratory routine because the information deriving from their measurement, although of speculative and scientific interest, has limited clinical value at present. Nevertheless, even if they have no impact on patient management, these substances do have a potential role to play in the study of cancer patients, and should be taken into account when developing new therapeutic strategies.
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Affiliation(s)
- C Botti
- Nuclear Medicine Department, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milano, Italy
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Retroviral envelope proteins: Involvement in neuropathogenesis. J Neurol Sci 2017; 380:151-163. [DOI: 10.1016/j.jns.2017.07.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 06/23/2017] [Accepted: 07/18/2017] [Indexed: 02/07/2023]
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Laska MJ, Troldborg A, Hauge EM, Bahrami S, Stengaard-Pedersen K. Human Endogenous Retroviral Genetic Element With Immunosuppressive Activity in Both Human Autoimmune Diseases and Experimental Arthritis. Arthritis Rheumatol 2017; 69:398-409. [DOI: 10.1002/art.39867] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 09/01/2016] [Indexed: 11/05/2022]
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Vargiu L, Rodriguez-Tomé P, Sperber GO, Cadeddu M, Grandi N, Blikstad V, Tramontano E, Blomberg J. Classification and characterization of human endogenous retroviruses; mosaic forms are common. Retrovirology 2016; 13:7. [PMID: 26800882 PMCID: PMC4724089 DOI: 10.1186/s12977-015-0232-y] [Citation(s) in RCA: 182] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 12/16/2015] [Indexed: 02/06/2023] Open
Abstract
Background Human endogenous retroviruses (HERVs) represent the inheritance of ancient germ-line cell infections by exogenous retroviruses and the subsequent transmission of the integrated proviruses to the descendants. ERVs have the same internal structure as exogenous retroviruses. While no replication-competent HERVs have been recognized, some retain up to three of four intact ORFs. HERVs have been classified before, with varying scope and depth, notably in the RepBase/RepeatMasker system. However, existing classifications are bewildering. There is a need for a systematic, unifying and simple classification. We strived for a classification which is traceable to previous classifications and which encompasses HERV variation within a limited number of clades. Results The human genome assembly GRCh 37/hg19 was analyzed with RetroTector, which primarily detects relatively complete Class I and II proviruses. A total of 3173 HERV sequences were identified. The structure of and relations between these proviruses was resolved through a multi-step classification procedure that involved a novel type of similarity image analysis (“Simage”) which allowed discrimination of heterogeneous (noncanonical) from homogeneous (canonical) HERVs. Of the 3173 HERVs, 1214 were canonical and segregated into 39 canonical clades (groups), belonging to class I (Gamma- and Epsilon-like), II (Beta-like) and III (Spuma-like). The groups were chosen based on (1) sequence (nucleotide and Pol amino acid), similarity, (2) degree of fit to previously published clades, often from RepBase, and (3) taxonomic markers. The groups fell into 11 supergroups. The 1959 noncanonical HERVs contained 31 additional, less well-defined groups. Simage analysis revealed several types of mosaicism, notably recombination and secondary integration. By comparing flanking sequences, LTRs and completeness of gene structure, we deduced that some noncanonical HERVs proliferated after the recombination event. Groups were further divided into envelope subgroups (altogether 94) based on sequence similarity and characteristic “immunosuppressive domain” motifs. Intra and inter(super)group, as well as intraclass, recombination involving envelope genes (“env snatching”) was a common event. LTR divergence indicated that HERV-K(HML2) and HERVFC had the most recent integrations, HERVL and HUERSP3 the oldest. Conclusions A comprehensive HERV classification and characterization approach was undertaken. It should be applicable for classification of all ERVs. Recombination was common among HERV ancestors. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0232-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Laura Vargiu
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy. .,Center for Advanced Studies, Research and Development in Sardinia, CRS4, Pula, Italy. .,Nurideas S.r.l., Cagliari, Italy.
| | - Patricia Rodriguez-Tomé
- Center for Advanced Studies, Research and Development in Sardinia, CRS4, Pula, Italy. .,Nurideas S.r.l., Cagliari, Italy.
| | - Göran O Sperber
- Physiology Unit, Department of Neuroscience, Uppsala University, Uppsala, Sweden.
| | - Marta Cadeddu
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.
| | - Nicole Grandi
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.
| | - Vidar Blikstad
- Department of Medical Sciences, Uppsala University Hospital, Dag Hammarskjölds Väg 17, Uppsala, 751 85, Sweden.
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.
| | - Jonas Blomberg
- Department of Medical Sciences, Uppsala University Hospital, Dag Hammarskjölds Väg 17, Uppsala, 751 85, Sweden.
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Anti-inflammatory and vasoprotective activity of a retroviral-derived peptide, homologous to human endogenous retroviruses: endothelial cell effects. PLoS One 2012; 7:e52693. [PMID: 23285152 PMCID: PMC3527569 DOI: 10.1371/journal.pone.0052693] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 11/21/2012] [Indexed: 01/13/2023] Open
Abstract
Malignant and inflammatory tissues sometimes express endogenous retroviruses or their proteins. A highly-conserved sequence from retroviral transmembrane (TM) proteins, termed the “immunosuppressive domain (ID)”, is associated with inhibition of immune and inflammatory functions. An octadecapeptide (MN10021) from the ID of retroviral TM protein p15E inhibits in vitro release of pro-inflammatory cytokines and increases synthesis of anti-inflammatory IL-10. We sought to determine if MN10021 has significant in vivo effects. MN10021, prepared by solid-phase synthesis, was dimerized through a naturally-occurring, carboxy-terminal cysteine. In vivo anti-inflammatory activity was determined using a murine model of sodium periodate (NaIO4)-induced peritonitis. In vivo vasoprotective effects were determined using: (1) a carrageenan-induced model of disseminated intravascular coagulation (DIC) in mice; (2) a reverse passive Arthus model in guinea pigs; and (3) vasoregulatory effects in spontaneously hypertensive rats (SHR). In vitro studies included: (1) binding/uptake of MN10021 using human monocytes, cultured fibroblasts, and vascular endothelial cells (VEC); (2) gene expression by RT-PCR of MN10021-treated VEC; and (3) apoptosis of MN10021-treated VEC exposed to staurosporine or TNF-α. One-tenth nmol MN10021 inhibits 50 percent of the inflammatory response in the mouse peritonitis model. Furthermore, 73 nmol MN10021 completely protects mice in a lethal model of carrageenan-induced DIC and inhibits vascular leak in both the mouse DIC model and a guinea pig reverse passive Arthus reaction. MN10021 binds to and is taken up in a specific manner by both human monocytes and VEC but not by cultured human fibroblasts. Surprisingly, orally-administered MN10021 lowers blood pressure in SHR rats by 10–15% within 1 h suggesting a direct or indirect effect on the vascular endothelium. MN10021 and derived octapeptides induce iNOS (inducible nitric oxide synthase) mRNA in VEC and nitrate in VEC cell culture supernatants and protect VEC from induced apoptosis or necrosis. However, pretreatment of VEC with nitro-L-arginine methyl ester (L-NAME), while inhibiting the release of nitrate, does not block the anti-apoptotic effect of MN10021 and derived octapeptides suggesting that their potent vasoprotective and anti-inflammatory activity is not nitric oxide dependent.
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Tolosa J, Schjenken J, Clifton V, Vargas A, Barbeau B, Lowry P, Maiti K, Smith R. The endogenous retroviral envelope protein syncytin-1 inhibits LPS/PHA-stimulated cytokine responses in human blood and is sorted into placental exosomes. Placenta 2012; 33:933-41. [DOI: 10.1016/j.placenta.2012.08.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 08/09/2012] [Accepted: 08/27/2012] [Indexed: 12/25/2022]
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Phylogeny-directed search for murine leukemia virus-like retroviruses in vertebrate genomes and in patients suffering from myalgic encephalomyelitis/chronic fatigue syndrome and prostate cancer. Adv Virol 2011; 2011:341294. [PMID: 22315600 PMCID: PMC3265301 DOI: 10.1155/2011/341294] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Revised: 06/11/2011] [Accepted: 06/22/2011] [Indexed: 01/20/2023] Open
Abstract
Gammaretrovirus-like sequences occur in most vertebrate genomes. Murine Leukemia Virus (MLV) like retroviruses (MLLVs) are a subset, which may be pathogenic and spread cross-species. Retroviruses highly similar to MLLVs (xenotropic murine retrovirus related virus (XMRV) and Human Mouse retrovirus-like RetroViruses (HMRVs)) reported from patients suffering from prostate cancer (PC) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) raise the possibility that also humans have been infected. Structurally intact, potentially infectious MLLVs occur in the genomes of some mammals, especially mouse. Mouse MLLVs contain three major groups. One, MERV G3, contained MLVs and XMRV/HMRV. Its presence in mouse DNA, and the abundance of xenotropic MLVs in biologicals, is a source of false positivity. Theoretically, XMRV/HMRV could be one of several MLLV transspecies infections. MLLV pathobiology and diversity indicate optimal strategies for investigating XMRV/HMRV in humans and raise ethical concerns. The alternatives that XMRV/HMRV may give a hard-to-detect “stealth” infection, or that XMRV/HMRV never reached humans, have to be considered.
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Balada E, Ordi-Ros J, Vilardell-Tarrés M. Molecular mechanisms mediated by human endogenous retroviruses (HERVs) in autoimmunity. Rev Med Virol 2009; 19:273-86. [DOI: 10.1002/rmv.622] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Haraguchi S, Good RA, Day-Good NK. A potent immunosuppressive retroviral peptide: cytokine patterns and signaling pathways. Immunol Res 2008; 41:46-55. [PMID: 18506644 DOI: 10.1007/s12026-007-0039-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A synthetic bioactive peptide composed of 17 amino acids (CKS-17) homologous to a highly conserved region of human and animal retroviral transmembrane envelope proteins induces not only significant immunoregulatory functions but also exhibits Th1-inhibiting properties, as described by its ability to suppress cell-mediated immunity and inhibit the production of interleukin (IL) 12, IL-2, gamma interferon, and tumor necrosis factor alpha, while enhancing IL-10. An important molecular mechanism responsible for the observed cytokine profiles by CKS-17 is provided by our findings demonstrating that this small peptide activates several intracellular signaling molecules, i.e., elevates intracellular cyclic adenosine monophosphate (cAMP) levels, and induces phosphorylation of extracellular signal-regulated kinase (ERK) 1 and 2, mitogen-activated protein kinase/ERK kinase (MEK), protein kinase D, Raf1, and phospholipase C gamma1 (PLCgamma1). The activation of ERK1/2 is via the PLCgamma1-protein kinase C-Raf1-MEK signaling cascade. The activation of both ERK1/2 and cAMP appears to be via a mechanism sensitive to AG879, a receptor tyrosine kinase inhibitor, but not to AG825, AG1296, or AG1478. Furthermore, phosphoinositide-3 kinase appears to mediate the CKS-17-induced activation of ERK1/2, but not of cAMP. A specific amino acid sequence as well as the dimerization of this peptide is required to confer these biological activities. The results obtained are compelling and reproducible. This highly conserved molecule may enable us to understand a basic mechanism(s) of intracellular signaling pathways, regulation of Th1/Th2 cytokines, immunosuppression, and immunologic tolerance.
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Affiliation(s)
- Soichi Haraguchi
- Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, University of South Florida, Children's Research Institute, 140 Seventh Avenue South, CRI 4008, St. Petersburg, FL 33701, USA.
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Fan TX, Day NK, Luangwedchakarn V, Chang Y, Ikehara S, Lerner DL, Haraguchi S. The phosphorylation of phospholipase C-gamma1, Raf-1, MEK, and ERK1/2 induced by a conserved retroviral peptide. Peptides 2005; 26:2165-74. [PMID: 15978701 DOI: 10.1016/j.peptides.2005.04.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Revised: 04/13/2005] [Accepted: 04/14/2005] [Indexed: 01/12/2023]
Abstract
A synthetic 17-amino acid peptide (CKS-17) homologous to a highly conserved region of human and animal retroviral transmembrane proteins has been found to exhibit suppressive properties for numerous immune functions. It has been shown that CKS-17 causes an imbalance of human types 1 and 2 cytokines and inhibition of the immune responses of lymphocytes, monocytes, and macrophages. CKS-17 induced increased intracellular levels of cAMP, which plays an important role in regulation of cytokine biosynthesis. In this study, using a Jurkat T-cell line and Western blot analysis, CKS-17 induced phosphorylation of PLC-gamma1, Raf-1, MEK and ERK1/2. Using a PLC selective inhibitor U73122 or PLC-gamma1-deficient Jurkat cell line, phosphorylation induced by CKS-17 of ERK1/2, PLC-gamma1, or Raf-1, respectively, were undetectable or significantly reduced. Reintroduction of PLC-gamma1 into the PLC-gamma1-deficient Jurkat cells restored the phosphorylation of ERK1/2 and PLC-gamma1 induced by CKS-17. Further, pretreatment of Jurkat cells with PKC inhibitors blocks the phosphorylation of Raf-1, MEK, and ERK1/2 induced by CKS-17. These results indicate that CKS-17 induces the PLC-gamma1-PKC-Raf-1-MEK-ERK1/2 signaling pathway.
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Affiliation(s)
- Tian xue Fan
- Department of Pediatrics, University of South Florida, All Children's Hospital, St. Petersburg, FL 33701, USA
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12
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De Boer EC, Teppema JS, Steerenberg PA, De Jong WH. Retrovirus type C in the mouse bladder carcinoma cell line MBT-2. J Urol 2000; 163:1999-2001. [PMID: 10799246 DOI: 10.1097/00005392-200006000-00109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The presence of replicating type C retrovirus in MBT-2 mouse bladder carcinoma cells is reported. This MBT-2 tumor cell line is nowadays globally distributed. The cells have been and are still used to study various aspects of bladder cancer. While studying the phagocytic capacity of MBT-2 cells for BCG organisms by electron microscopic methods, the presence of this retrovirus was noticed. MATERIALS AND METHODS MBT-2 cells that were cultured in vitro as well as cells from intravesically and intradermally grown MBT-2 tumors from syngeneic mice were investigated using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques. RESULTS All samples including the earliest generation MBT-2 cells that could be traced from stocks of other research groups contained the C type retrovirus, suggesting a contamination in all available generations of the MBT-2 cell line. CONCLUSIONS As this tumor cell line is widely used in immunologic studies of the response to bladder cancer, it is important to consider the possible presence of type C viruses and associated antigens, since they could contribute to or interfere with the responses being measured. Studies should be initiated to determine whether viral antigen expression is involved in the immune rejection of MBT-2 bladder cancer. As a consequence, clinical implementation of immunological treatment strategies should not be based on results obtained with the MBT-2 model alone, but preferably should be confirmed with other (bladder) carcinoma models.
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Affiliation(s)
- E C De Boer
- Department of Urology, University of Amsterdam, Amsterdam, The Netherlands
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Clerici M, Fusi ML, Caputo D, Guerini FR, Trabattoni D, Salvaggio A, Cazzullo CL, Arienti D, Villa ML, Urnovitz HB, Ferrante P. Immune responses to antigens of human endogenous retroviruses in patients with acute or stable multiple sclerosis. J Neuroimmunol 1999; 99:173-82. [PMID: 10505972 DOI: 10.1016/s0165-5728(99)00123-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A possible role for human endogenous retroviruses (HERV) in the pathogenesis of MS was investigated by analyzing HERV peptides-stimulated proliferation and cytokine production in MS patients with acute (AMS) or stable (SMS) disease. HERV peptides specific-proliferation and type 1 cytokine production by peripheral blood mononuclear cells was observed in AMS but not in SMS individuals, in whom a type 2 cytokine profile dominates. HERV peptides-stimulated immune responses were modified by changes in disease expression; mediated by CD4+ T lymphocytes; and not related to HLA class II molecules. These data suggest the possibility of a pathogenic role for HERV and HERV-specific immune responses in MS.
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Affiliation(s)
- M Clerici
- Cattedra di Immunologia, Università degli Studi di Milano, Padiglione LITA, Ospedale L. Sacco, Milan, Italy.
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Lindeskog M, Mager DL, Blomberg J. Isolation of a human endogenous retroviral HERV-H element with an open env reading frame. Virology 1999; 258:441-50. [PMID: 10366582 DOI: 10.1006/viro.1999.9750] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
About 100 elements of the human endogenous retroviral HERV-H family have full-length env genes potentially coding for Env proteins with sequences highly similar to the immunosuppressive peptide CKS-17 from the MLV transmembrane protein p15E. However, previously sequenced HERV-H env genes have contained stop codons or framehifts. To isolate elements with open env reading frames, we first tried to assess the diversity of HERV-H env genes by comparing PCR-generated env sequences from genomic DNA with published HERV-H sequences. A region at the beginning of env displayed a similarity of 84-98% among 15 different elements. We then used a probe from one of the PCR-generated clones, 98% similar to the consensus sequence in this region, to screen a human genomic lambda library. Three HERV-H elements displaying ca. 98% identity in the env gene were isolated and were shown to have integrated relatively recently, after the divergence of the orangutan and the african great ape lineages. One of these elements, HERV-H19, had a 1752-bp open env reading frame, producing a 77-kDa Env protein in in vitro translation reactions. This is the first demonstration of a coding competent member of the HERV-H family. These findings raise the possibility that HERV-H Env proteins may play a biological role in human cells.
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Affiliation(s)
- M Lindeskog
- Section of Virology, Lund University, Sölvegatan 23, Lund, S-22362, Sweden.
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Kerrebijn JD, Balm AJ, Freeman JL, Dosch HM, Drexhage HA. Who is in control of the immune system in head and neck cancer? Crit Rev Oncol Hematol 1999; 31:31-53. [PMID: 10532189 DOI: 10.1016/s1040-8428(99)00011-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- J D Kerrebijn
- Department of Otolaryngology/Head and Neck Surgery, Mount Sinai Hospital, Toronto, Ont., Canada
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Kabeya H, Ohashi K, Sugimoto C, Onuma M. Characterization of immune responses caused by bovine leukemia virus envelope peptides in sheep. J Vet Med Sci 1999; 61:475-80. [PMID: 10379937 DOI: 10.1292/jvms.61.475] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To study the immunomodulative activity caused by bovine leukemia virus envelope (BLV Env) peptide, sheep were immunized with two kinds of Th-epitope peptides, peptide 98 (BLV Env 98-117), and 61 (BLV Env 61-78). Four of eight immunized sheep showed specific proliferative responses against both of the peptide stimulations. To characterize the cells responding to the peptides, peptide-specific cells were established from the responding sheep by the continuous stimulation of peripheral blood mononuclear cells (PBMCs) with either peptide 98 or 61 in vitro. The peptide 98-specific cells consisted of CD4-positive cells, whereas the peptide 61-specific cells consisted of CD8-positive cells and MHC class II-positive cells. In addition, cytokine profile analysis indicated that the peptide 98-stimulated cells expressed IFN-gamma but not IL-10, although the peptide 61-stimulated cells expressed IL-10 but not IFN-gamma. These results show that BLV envelope peptides 98 and 61 can modulate immune responses of sheep lymphocytes in different ways and may contribute to the pathogenesis of BLV infection.
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Affiliation(s)
- H Kabeya
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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Kabeya H, Ohashi K, Sugimoto C, Onuma M. Bovine leukaemia virus envelope peptides cause immunomodulation in BALB/c mice. Vet Immunol Immunopathol 1999; 68:39-48. [PMID: 10231950 DOI: 10.1016/s0165-2427(99)00005-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Immunomodulatory activity of two bovine leukaemia virus envelope (BLVEnv) derived peptides were examined in BALB/c mice. One is peptide homologous to CKS-17 which is known as a 17-amino acid peptide derived from p15E of feline leukaemia virus (CKS-17/BLV), and the other is an 18-amino acid synthetic peptide of BLV Env 61-78 (pep61). Priming with CKS-17/BLV in vitro, as well as CKS-17, significantly suppressed the mitogen-induced proliferative responses of spleen cells in naive BALB/c mice. In addition, priming of spleen cells with pep61 in vitro and in vivo resulted in suppression of lipopolysaccaride-induced B-cell proliferative response. This suppression was partially due to the basic amino acid sequence in the peptide because if the pep61-derived peptide lacking Arg was used, this inhibitory activity was partially restored. In contrast, pep61 enhanced both concanavalin A-stimulated proliferative response and IL-2 production. These findings showed that pep61 may contribute to the modification of the host immune responses in the course of BLV infection.
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Affiliation(s)
- H Kabeya
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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Mangeney M, Heidmann T. Tumor cells expressing a retroviral envelope escape immune rejection in vivo. Proc Natl Acad Sci U S A 1998; 95:14920-5. [PMID: 9843991 PMCID: PMC24551 DOI: 10.1073/pnas.95.25.14920] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A model system for the in vivo control of tumor cell proliferation by the immune system has been used to assay for the possible immunosuppressive activity of retroviral proteins. Expression vectors for the entire or the transmembrane subunit of the Moloney murine leukemia virus envelope protein were constructed, as well as control vectors for irrelevant transmembrane proteins-or no protein. They were introduced either into MCA205 murine tumor cells, which do not proliferate upon s.c. injection into an allogeneic host, or into CL8.1 murine tumor cells, which overexpress class I antigens and are rejected in a syngeneic host. In both cases, expression of the complete envelope protein or of the transmembrane subunit resulted in tumor growth in vivo, with no effect of control vectors. Tumor cell growth results from inhibition of the host immune response, as the envelope-dependent effect was no more observed for MCA205 cells in syngeneic mice or for CL8.1 cells in x-irradiated mice. This inhibition is local because it is not observed at the level of control tumor cells injected contralaterally. These results suggest a noncanonical function of retroviral envelopes in the "penetrance" of viral infections, as well as a possible involvement of the envelope proteins of endogenous retroviruses in tumoral processes.
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Affiliation(s)
- M Mangeney
- Unité des Rétrovirus Endogènes et Eléments Rétroïdes des Eukaryotes Supérieurs, Unité Mixte de Recherche 1573, Centre National de la Recherche Scientifique, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif, France
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Abstract
Endogenous retroviruses (ERVs) are estimated to comprise up to 1% of human DNA. While the genome of many ERVs is interrupted by termination codons, deletions or frame shift mutations, some ERVs are transcriptionally active and recent studies reveal protein expression or particle formation by human ERVs. ERVs have been implicated as aetiological agents of autoimmune disease, because of their structural and sequence similarities to exogenous retroviruses associated with immune dysregulation and their tissue-specific or differentiation-dependent expression. In fact, retrovirus-like particles distinct from those of known exogenous retroviruses and immune responses to ERV proteins have been observed in autoimmune disease. Quantitatively or structurally aberrant expression of normally cryptic ERVs, induced by environmental or endogenous factors, could initiate autoimmunity through direct or indirect mechanisms. ERVs may lead to immune dysregulation as insertional mutagens or cis-regulatory elements of cellular genes involved in immune function. ERVs may also encode elements like tax in human T-lymphotrophic virus type I (HTLV-I) or tat in human immunodeficiency virus-I (HIV-I) that are capable of transactivating cellular genes. More directly, human ERV gene products themselves may be immunologically active, by analogy with the superantigen activity in the long terminal repeat (LTR) of mouse mammary tumour viruses (MMTV) and the non-specific immunosuppressive activity in mammalian type C retrovirus env protein. Alternatively, increased expression of an ERV protein, or expression of a novel ERV protein not expressed in the thymus during acquisition of immune tolerance, may lead to its perception as a neoantigen. Paraneoplastic syndromes raise the possibility that novel ERV-encoded epitopes expressed by a tumour elicit immunity to cross-reactive epitopes in normal tissues. Recombination events between different but related ERVs, to whose products the host is immunologically tolerant, may also generate new antigenic determinants. Frequently reported humoral immunity to exogenous retrovirus proteins in autoimmune disease could be elicited by cross-reactive ERV proteins. A review of the evidence implicating ERVs in immune dysfunction leads to the conclusion that direct molecular studies are likely to establish a pathogenic role for ERVs in autoimmune disease.
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Affiliation(s)
- K Nakagawa
- Burnet Clinical Research Unit, Walter and Eliza Hall Institute of Medical Research, Royal Melbourne Hospital, Parkville, Australia
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20
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Lang MS, Hovenkamp E, Savelkoul HF, Knegt P, Van Ewijk W. Immunotherapy with monoclonal antibodies directed against the immunosuppressive domain of p15E inhibits tumour growth. Clin Exp Immunol 1995; 102:468-75. [PMID: 8536359 PMCID: PMC1553370 DOI: 10.1111/j.1365-2249.1995.tb03839.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Immunosuppressive retrovirus-related proteins, like p15E, are involved in tumour-associated immunosuppression. In the present study we investigated whether such proteins could be used as targets in tumour immunotherapy using MoAbs. Immunotherapy was performed in mice inoculated with the Rauscher virus-transformed myeloid cell line RMB-1. RMB-1 cells express retroviral antigens at their cell surface. In order to obtain constant serum titres of MoAbs over a prolonged period of time during therapy, anti-p15E antibody-producing hybridoma cells were encapsulated in alginate and injected intraperitoneally in tumour-bearing mice. Using this technique, serum antibody titres of 50-100 micrograms/ml were obtained, which remained constant over a period of at least 3 weeks. Therapy experiments were performed using anti-p15E antibodies 19F8, which recognizes both cell surface-associated as well as circulating p15E, and ER-IS5, which did not react with surface-bound p15E beyond background, but which neutralizes circulating p15E. Inoculation of alginates containing anti-p15E hybridoma cell lines in RMB-1 tumour-bearing mice showed inhibition of tumour cell growth. In survival experiments, 19F8 cured eight of 23 tumour-bearing mice. The p15E neutralizing antibody ER-IS5 caused a significant longer survival, but therapy with this MoAb alone was not sufficient to cure the animals of the RMB-1 tumour.
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Affiliation(s)
- M S Lang
- Department of Immunology, Erasmus University, Rotterdam, The Netherlands
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21
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Haraguchi S, Good RA, Day NK. Immunosuppressive retroviral peptides: cAMP and cytokine patterns. IMMUNOLOGY TODAY 1995; 16:595-603. [PMID: 8579753 DOI: 10.1016/0167-5699(95)80083-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mechanism(s) by which retroviral proteins exert immunosuppressive influences has remained enigmatic. Here, Soichi Haraguchi, Robert Good and Noorbibi Day propose that induction of intracellular cAMP by a synthetic, immunosuppressive, retroviral envelope peptide causes a shift in the cytokine balance, leading to suppression of cell-mediated immunity by upregulation of interleukin 10 (IL-10) and downregulation of IL-2, IL-12 and tumor necrosis factor alpha production. This may be a crucial step towards generation of immune dysfunction.
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Affiliation(s)
- S Haraguchi
- Dept of Pediatrics, All Children's Hospital, University of South Florida College of Medicine, St Petersburg 33701, USA
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22
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Haraguchi S, Good RA, James-Yarish M, Cianciolo GJ, Day NK. Differential modulation of Th1- and Th2-related cytokine mRNA expression by a synthetic peptide homologous to a conserved domain within retroviral envelope protein. Proc Natl Acad Sci U S A 1995; 92:3611-5. [PMID: 7724606 PMCID: PMC42217 DOI: 10.1073/pnas.92.8.3611] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The influence of a synthetic retroviral peptide, CKS-17, on T helper type 1 (Th1)- or Th2-related cytokines was investigated in human blood mononuclear cells. Cells were stimulated with staphylococcal enterotoxin A, anti-CD3 plus anti-CD28 monoclonal antibodies, or lipopolysaccharide to induce cytokine mRNA. mRNA was detected by a reverse transcription-polymerase chain reaction or Northern blot analysis. CKS-17 down-regulated stimulant-induced mRNA accumulation for interferon gamma (IFN-gamma), interleukin (IL)-2, and p40 heavy and p35 light chains of IL-12, a cytokine that mediates development of Th1 response. CKS-17 up-regulated stimulant-induced mRNA accumulation of IL-10 and did not suppress Th2-related cytokine (IL-4, IL-5, IL-6, or IL-13) mRNA expression. A reverse sequence of CKS-17 peptide, used as a control, showed no such action. Anti-human IL-10 monoclonal antibody blocked ability of CKS-17 to inhibit mRNA accumulation for IFN-gamma but not the CKS-17 suppressive activity of IL-12 p40 heavy chain mRNA. Thus, CKS-17-mediated suppression of IFN-gamma mRNA expression is dependent upon augmentation of IL-10 production by CKS-17. This conserved component of several retroviral envelope proteins, CKS-17, may act as an immunomodulatory epitope responsible for cytokine dysregulation that leads to suppression of cellular immunity.
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Affiliation(s)
- S Haraguchi
- Department of Pediatrics, All Children's Hospital, University of South Florida College of Medicine, St. Petersburg 33701, USA
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23
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Simons PJ, Oostendorp RA, Tas MP, Drexhage HA. Comparison of retroviral p15E-related factors and interferon alpha in head and neck cancer. Cancer Immunol Immunother 1994; 38:178-84. [PMID: 8124686 PMCID: PMC11038406 DOI: 10.1007/bf01525639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/1993] [Accepted: 10/07/1993] [Indexed: 01/28/2023]
Abstract
Head and neck squamous cell carcinomas (HNscc) produce low-molecular-mass factors (low-M(r) factors, M(r) < or = 25,000), which are antigenically related to the immunosuppressive retroviral transmembrane envelope protein p15E. These P15E-related tumour factors are thought to be responsible for some immunological impairments found in these patients (particularly the defective monocyte chemotaxis). A sequential and functional homology has been reported to exist between a bioactive fragment of interferon alpha (IFN alpha) and the putative immunosuppressive region of retroviral p15E (CKS-17). In this study we investigated (a) a possible functional and structural relationship between p15E and IFN alpha, and (b) the presence of and the relationship between p15E-related low-M(r) factors and IFN alpha in HNscc patients. We report the following results. (a) Recombinant human (rhu) IFN alpha was able to inhibit monocyte chemotaxis. (b) The anti-p15E antibodies crossreacted with rhuIFN alpha in a dot-blot technique; however, the anti-IFN alpha antibodies did not crossreact with disrupted murine leukaemia virus (p15E source). (c) Low-M(r) factors (n = 8-11) prepared from the sera of HNscc patients, which inhibit the monocyte chemotactic responsiveness, could be adsorbed by the anti-p15E antibodies as well as by the anti-IFN alpha antibodies. However, the abilities of the factors to adsorb to the two categories of antibodies (namely, anti-p15E and anti-IFN alpha) did not correlate. (d) Immunohistochemically we found IFN alpha-related epitopes, in almost all HNscc specimens studied (17/18), in locations distinctive from those of p15E-related factors. The anti-IFN alpha antibodies used in this study mainly reacted with basal epithelial cells close to the basal membrane, the prickle and granular cells of the squamous cell carcinomas. The anti-p15E antibodies mainly reacted with corneal layers, the granular and prickle cells, and did not react with basal epithelial cells. Our findings suggest that the immunosuppressive factors produced by HNscc cells are heterogeneous and p15E- and/or IFN alpha-related.
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Affiliation(s)
- P J Simons
- Department of Immunology, Erasmus University, Rotterdam, The Netherlands
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24
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Grohmann U, Fioretti MC, Binaglia L, Belladonna ML, Bianchi R, Puccetti P. Immunogenic properties of retroviral protein P15E from drug-treated murine mastocytoma P815. Int J Cancer 1993; 55:344-50. [PMID: 7690350 DOI: 10.1002/ijc.2910550227] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A triazene-xenogenized tumor sub-line was derived from the mouse mastocytoma cell line P815 following several transplant generations in vivo on DTIC. The highly immunogenic P815/DTIC variant line expressed new CTL-defined antigens. Novel antigens were also detected by antibodies in immunoprecipitation and by Western blot analysis. Upon immunoprecipitation of metabolically labeled cells, one such variant-specific 20-kDa antigen was shown to be related to retroviral envelope protein p15E. When injected intrasplenically into recipient mice, the electroblotted nitrocellulose-bound 20-kDa antigen resulted in increased frequency in CTL precursors to P815/DTIC cells. In addition to previous data in the L5178Y/DTIC tumor-model system, these data suggest that expression of aberrant, retrovirus-related proteins may be a common finding in different parental tumors xenogenized by triazene treatment.
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Affiliation(s)
- U Grohmann
- University of Perugia, Department of Experimental Medicine and Biochemical Sciences, Italy
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25
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Foulds S, Wakefield CH, Giles M, Gillespie J, Dye JF, Guillou PJ. Expression of a suppressive p15E-related epitope in colorectal and gastric cancer. Br J Cancer 1993; 68:610-6. [PMID: 7688979 PMCID: PMC1968406 DOI: 10.1038/bjc.1993.395] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
mRNA for the suppressive epitope of p15E was found to be present in 24 of 30 samples of human colorectal cancer and in all four specimens of gastric cancer. mRNA for p15E was seldom seen in nonmalignant colonic or gastric mucosa but, when present, was associated with inflammatory or pre-malignant conditions of the digestive tract. Synthetic peptides derived from the conserved p15E sequence were found to suppress some aspects of the immune response implicated in anti-tumour activity. These data suggest that a p15E-related material with immunomodulatory properties is elaborated within human tumours, either by the tumour itself or as a normal component of the endogenous anti-tumour reaction.
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Affiliation(s)
- S Foulds
- Academic Surgical Unit, Imperial College of Science, Technology and Medicine, St Mary's Hospital Medical School, London, UK
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26
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Oostendorp RA, Meijer CJ, Scheper RJ. Immunosuppression by retroviral-envelope-related proteins, and their role in non-retroviral human disease. Crit Rev Oncol Hematol 1993; 14:189-206. [PMID: 8397847 DOI: 10.1016/1040-8428(93)90009-s] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- R A Oostendorp
- GSF-Institute for Experimental Hematology, München, Germany
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27
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Lindeskog M, Medstrand P, Blomberg J. Sequence variation of human endogenous retrovirus ERV9-related elements in an env region corresponding to an immunosuppressive peptide: transcription in normal and neoplastic cells. J Virol 1993; 67:1122-6. [PMID: 8419641 PMCID: PMC237471 DOI: 10.1128/jvi.67.2.1122-1126.1993] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Evolutionarily conserved sequences corresponding to an immunosuppressive region in retroviral transmembrane proteins were amplified by the polymerase chain reaction from human genomic DNA and reverse-transcribed RNA from one glioma, three pieces of macroscopically normal brain tissue, kidney, lymphocytes, cultured embryonic lung cells, and a rhabdomyosarcoma cell line. Amplification products (125 bp) from DNA and RNA from the glioma and RNA from one normal piece of brain tissue were cloned and sequenced (45 clones). A variety of sequences similar to ERV9 (75 to 93%) were identified. Amplification products were immobilized on nylon filters and hybridized to four different synthetic oligonucleotides derived from the sequenced clones. Sequences without the stop codon seen in ERV9 in this region, possibly encoding functional immunosuppressive proteins, were present in RNA amplificates from all samples. The various cell types showed different hybridization patterns with the four probes. The open reading frame sequences were identified in genomic Southern blots, one probe detecting about 10 copies and another detecting a single copy. Northern (RNA) blots of mRNA from various normal human tissues revealed 2.5-kb (e.g., lung) and 10-kb (e.g., placenta) transcripts hybridizing to one of the probes.
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Affiliation(s)
- M Lindeskog
- Department of Medical Microbiology, University of Lund, Sweden
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28
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Gauduin MC, Vogel FR, Simon JP, Audibert FA, Chedid LA. Modulation of the immunosuppressive activity of CKS-17, a synthetic retroviral envelope peptide, by muramyl dipeptide. Viral Immunol 1993; 6:175-83. [PMID: 8292225 DOI: 10.1089/vim.1993.6.175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
CKS-17, a heptadecapeptide corresponding to a region highly conserved in retroviral transmembrane proteins is known to be immunosuppressive both in vitro and in vivo when conjugated to a carrier protein. Here we examined the effect of the synthetic adjuvant muramyl dipeptide (MDP) on the immunosuppressive properties of CKS-17-BSA in vitro. MDP was found to abrogate CKS-17-BSA-induced inhibition of both IgM plaque-forming cell responses and antitetanus toxin IgG secretion by BALB/c mouse spleen cells immunized in vivo and in vitro by sheep red blood cells and tetanus toxoid, respectively. In contrast, the CKS-17-BSA suppression of concanavalin A-induced splenocyte proliferation was not abrogated by MDP. The data suggest that muramyl peptides could be useful as immunoadjuvants for vaccines against retrovirus-associated immunosuppressive diseases.
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Affiliation(s)
- M C Gauduin
- H. Lee Moffitt Cancer and Research Institute, University of South Florida College of Medicine, Tampa
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29
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Brody BA, Hunter E. Mutations within the env gene of Mason-Pfizer monkey virus: effects on protein transport and SU-TM association. J Virol 1992; 66:3466-75. [PMID: 1316462 PMCID: PMC241127 DOI: 10.1128/jvi.66.6.3466-3475.1992] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
By deletion mutagenesis analyses, we have examined the contribution of the immunosuppressive peptide (ISP) region within the transmembrane (TM) protein of Mason-Pfizer monkey virus to viral maturation and infectivity. Deletion of the entire region (mutant D105) results in the production of an Env precursor that is transport defective and therefore unable to be processed to mature glycoproteins. This mutation results in the release of noninfectious virions devoid of surface glycoproteins. A second deletion that removes the most highly conserved 11 amino acids of the ISP (mutant D33) does not affect the production, transport, or processing of the Env precursor yet produces virions that are noninfectious. The mutation was shown to cause the loss of interaction between the surface (SU) and TM proteins and result in the efficient shedding of gp70 into the culture medium. The released gp70 protein was biologically active and could still bind with high specificity to susceptible target cells. Since the ISP domain may represent an area of contact between SU and TM, it could provide an additional explanation for the amino acid sequence homology observed within this region of a variety of retroviruses.
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Affiliation(s)
- B A Brody
- Department of Microbiology, University of Alabama, Birmingham 35294
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30
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Oostendorp RA, Schaaper WM, Post J, Von Blomberg BM, Meloen RH, Scheper RJ. Suppression of lymphocyte proliferation by a retroviral p15E-derived hexapeptide. Eur J Immunol 1992; 22:1505-11. [PMID: 1534759 DOI: 10.1002/eji.1830220624] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
CKS-17 (LQNRRGLDLLFLKEGGL), a synthetic peptide derived from a conserved region of retroviral transmembrane proteins, has previously been shown to suppress several different immune effector mechanisms. The present study was undertaken to further delineate immunosuppressive site(s) of CKS-17. Overlapping hexapeptides covering the complete sequence of CKS-17 were synthesized. One CKS-17-derived hexapeptide, LDLLFL, suppressed ligand [CD3, interleukin (IL)-2]-induced lymphocyte proliferation. Spontaneous proliferation of transformed lymphoid cell lines, as well as cell lines from myeloid or epitheloid origin, was not inhibited by LDLLFL. Full suppression required the continuous presence of LDLLFL during culturing, and did not involve interference with monocyte function. Radiolabeling studies showed that the hexapeptide did not compete with IL-2 for IL-2 receptor binding. Most likely the LDLLFL motif interferes with steps shared by the IL-2 and CD3 receptor-induced signaling pathways. Since LDLLFL displays multiple immunosuppressive activities, it may constitute a biologically relevant immunosuppressive site of retroviral transmembrane proteins.
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MESH Headings
- Animals
- Antigens, Differentiation, T-Lymphocyte/physiology
- CD3 Complex
- Cell Division/drug effects
- Cells, Cultured
- Dose-Response Relationship, Drug
- Female
- Immune Tolerance/drug effects
- Intercellular Signaling Peptides and Proteins
- Interleukin-2/pharmacology
- Lymphocytes/physiology
- Mice
- Mice, Inbred BALB C
- Peptide Fragments/immunology
- Peptides/immunology
- Receptors, Antigen, T-Cell/physiology
- Receptors, Interleukin-2/metabolism
- Retroviridae Proteins, Oncogenic/immunology
- Time Factors
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/pathology
- Viral Envelope Proteins/immunology
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Affiliation(s)
- R A Oostendorp
- Department of Pathology, Free University Hospital, Amsterdam, The Netherlands
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31
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Haraguchi S, Liu WT, Cianciolo GJ, Good RA, Day NK. Suppression of human interferon-gamma production by a 17 amino acid peptide homologous to the transmembrane envelope protein of retroviruses: evidence for a primary role played by monocytes. Cell Immunol 1992; 141:388-97. [PMID: 1576656 DOI: 10.1016/0008-8749(92)90157-k] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
CKS-17, a synthetic amino acid peptide homologous to a highly conserved region of retroviral transmembrane protein exerts a suppressive action on staphylococcal enterotoxin A (SEA)-induced the production of IFN-gamma by human peripheral blood mononuclear cells (PBMC) (Ogasawara et al., J. Immunol. 141, 615, 1988). This action has been shown in the present study to be preceded by dramatic clustering of PBMC. Clusters appear within 3 hr of exposure of PBMC to CKS-17; they are dose dependent, inhibited by cycloheximide, and require a temperature of 37 degrees C. The cells in the clusters are predominantly monocytes. Although it has been previously shown that CKS-17 inhibits monocyte-mediated killing by inactivating IL-1 (Kleinerman et al., J. Immunol. 139, 2329, 1987) and production of IL-2 by murine thymoma cells treated with IL-1 (Gottlieb et al., J. Immunol. 142, 4321, 1989), in the present study we show that IL-1 does not prevent clustering of PBMC by CKS-17. Using CKS-17 and highly purified monocytes or lymphocytes, profound alterations occur only with monocytes, as revealed by light or electron microscopy. SEA- or staphylococcal enterotoxin B-induced production of IFN-gamma is inhibited when highly purified monocytes pretreated with CKS-17 are cocultured with highly purified T lymphocytes. Thus, CKS-17 induces dramatic clustering of cells apparently by inducing alterations of monocytes but not lymphocytes, suggesting that CKS-17 may interfere with the capacity of monocytes to facilitate production of IFN-gamma by T lymphocytes.
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Affiliation(s)
- S Haraguchi
- Department of Pediatrics, All Children's Hospital, University of South Florida, St. Petersburg 33701
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32
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Affiliation(s)
- D Sulitzeanu
- Lautenberg Center for General and Tumor Immunology, Hebrew University, Hadassah Medical School, Jerusalem
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33
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Nelson M, Nelson D. Inhibition of interleukin-2 production by tumor cell products and by CKS-17, a synthetic retroviral envelope peptide. Cancer Immunol Immunother 1990; 30:331-41. [PMID: 2302724 PMCID: PMC11038617 DOI: 10.1007/bf01786882] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/1989] [Accepted: 08/30/1989] [Indexed: 12/31/2022]
Abstract
Tumor cells of all types and species tested have been found to produce, in culture, substances that depress the expression of cell-mediated immunity, in the form of delayed-type hypersensitivity reactions in mouse feet. The factors responsible appear related immunologically to the retroviral envelope protein p15E. We have measured the effects of tumor products and conjugates of a p15E-related peptide, CKS-17, on interleukin-2 (IL-2) production by cultured, mitogen-stimulated EL4 cells; in this system IL-2 production is independent of IL-1. Supernatants of cultures of mouse, human and guinea-pig tumor cells inhibited IL-2 production in a dose-dependent fashion. CKS-17 conjugates, but not control conjugates, also inhibited IL-2 production. Responses to IL-2 of the CTLL line used were less inhibited by tumor products and very slightly inhibited by CKS-17 conjugates. IL-2 receptor density, assayed by flow cytometry, was not inhibited. IL-2 production was inhibited whether the tumor products or CKS-17 conjugates were added early or late in the course of culture of stimulated EL4 cells. Inhibition by CKS-17 conjugates was selective in that IL-2 production was inhibited to a greater degree than general protein synthesis in EL4 cells, and general protein synthesis by fibroblasts was unaffected. Measurement of IL-2 mRNA suggested that inhibition of IL-2 production was mediated post-transcriptionally. Fractionation of six different tumor supernatants on Sephacryl S-300 revealed a single peak of activity with an apparent molecular mass of 18 kDa. Antibodies to CKS-17 conjugates neutralized the inhibitory effect of native tumor products on IL-2 production. Inhibition of IL-2 production, by factors related to p15E, provides a strategically effective means of subversion of host defenses by tumors, and abrogation of this inhibition by means of antibodies might promote host resistance to tumor growth.
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Affiliation(s)
- M Nelson
- Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney, Australia
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