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Gabbianelli R, Shahar E, de Simone G, Rucci C, Bordoni L, Feliziani G, Zhao F, Ferrati M, Maggi F, Spinozzi E, Mahajna J. Plant-Derived Epi-Nutraceuticals as Potential Broad-Spectrum Anti-Viral Agents. Nutrients 2023; 15:4719. [PMID: 38004113 PMCID: PMC10675658 DOI: 10.3390/nu15224719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 10/29/2023] [Accepted: 10/31/2023] [Indexed: 11/26/2023] Open
Abstract
Although the COVID-19 pandemic appears to be diminishing, the emergence of SARS-CoV-2 variants represents a threat to humans due to their inherent transmissibility, immunological evasion, virulence, and invulnerability to existing therapies. The COVID-19 pandemic affected more than 500 million people and caused over 6 million deaths. Vaccines are essential, but in circumstances in which vaccination is not accessible or in individuals with compromised immune systems, drugs can provide additional protection. Targeting host signaling pathways is recommended due to their genomic stability and resistance barriers. Moreover, targeting host factors allows us to develop compounds that are effective against different viral variants as well as against newly emerging virus strains. In recent years, the globe has experienced climate change, which may contribute to the emergence and spread of infectious diseases through a variety of factors. Warmer temperatures and changing precipitation patterns can increase the geographic range of disease-carrying vectors, increasing the risk of diseases spreading to new areas. Climate change may also affect vector behavior, leading to a longer breeding season and more breeding sites for disease vectors. Climate change may also disrupt ecosystems, bringing humans closer to wildlife that transmits zoonotic diseases. All the above factors may accelerate the emergence of new viral epidemics. Plant-derived products, which have been used in traditional medicine for treating pathological conditions, offer structurally novel therapeutic compounds, including those with anti-viral activity. In addition, plant-derived bioactive substances might serve as the ideal basis for developing sustainable/efficient/cost-effective anti-viral alternatives. Interest in herbal antiviral products has increased. More than 50% of approved drugs originate from herbal sources. Plant-derived compounds offer diverse structures and bioactive molecules that are candidates for new drug development. Combining these therapies with conventional drugs could improve patient outcomes. Epigenetics modifications in the genome can affect gene expression without altering DNA sequences. Host cells can use epigenetic gene regulation as a mechanism to silence incoming viral DNA molecules, while viruses recruit cellular epitranscriptomic (covalent modifications of RNAs) modifiers to increase the translational efficiency and transcript stability of viral transcripts to enhance viral gene expression and replication. Moreover, viruses manipulate host cells' epigenetic machinery to ensure productive viral infections. Environmental factors, such as natural products, may influence epigenetic modifications. In this review, we explore the potential of plant-derived substances as epigenetic modifiers for broad-spectrum anti-viral activity, reviewing their modulation processes and anti-viral effects on DNA and RNA viruses, as well as addressing future research objectives in this rapidly emerging field.
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Affiliation(s)
- Rosita Gabbianelli
- Unit of Molecular Biology and Nutrigenomics, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (R.G.); (G.d.S.); (L.B.); (G.F.); (F.Z.)
| | - Ehud Shahar
- Department of Nutrition and Natural Products, Migal—Galilee Research Institute, Kiryat Shmona 11016, Israel;
- Department of Biotechnology, Tel-Hai College, Kiryat Shmona 1220800, Israel
| | - Gaia de Simone
- Unit of Molecular Biology and Nutrigenomics, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (R.G.); (G.d.S.); (L.B.); (G.F.); (F.Z.)
| | - Chiara Rucci
- Unit of Molecular Biology and Nutrigenomics, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (R.G.); (G.d.S.); (L.B.); (G.F.); (F.Z.)
| | - Laura Bordoni
- Unit of Molecular Biology and Nutrigenomics, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (R.G.); (G.d.S.); (L.B.); (G.F.); (F.Z.)
| | - Giulia Feliziani
- Unit of Molecular Biology and Nutrigenomics, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (R.G.); (G.d.S.); (L.B.); (G.F.); (F.Z.)
| | - Fanrui Zhao
- Unit of Molecular Biology and Nutrigenomics, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (R.G.); (G.d.S.); (L.B.); (G.F.); (F.Z.)
| | - Marta Ferrati
- Chemistry Interdisciplinary Project (ChIP) Research Centre, School of Pharmacy, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (M.F.); (F.M.); (E.S.)
| | - Filippo Maggi
- Chemistry Interdisciplinary Project (ChIP) Research Centre, School of Pharmacy, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (M.F.); (F.M.); (E.S.)
| | - Eleonora Spinozzi
- Chemistry Interdisciplinary Project (ChIP) Research Centre, School of Pharmacy, University of Camerino, Via Madonna delle Carceri, 62032 Camerino, Italy; (M.F.); (F.M.); (E.S.)
| | - Jamal Mahajna
- Department of Nutrition and Natural Products, Migal—Galilee Research Institute, Kiryat Shmona 11016, Israel;
- Department of Biotechnology, Tel-Hai College, Kiryat Shmona 1220800, Israel
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Wang L, Yan H, Zeng B, Hu Z. Research Progress on Cordycepin Synthesis and Methods for Enhancement of Cordycepin Production in Cordyceps militaris. Bioengineering (Basel) 2022; 9:bioengineering9020069. [PMID: 35200422 PMCID: PMC8869658 DOI: 10.3390/bioengineering9020069] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/17/2022] [Accepted: 02/09/2022] [Indexed: 12/04/2022] Open
Abstract
C. militaris is an insect-born fungus that belongs to Ascomycota and Cordyceps. It has a variety of biological activities that can be applied in medicine, health-care products, cosmeceuticals and other fields. Cordycepin (COR) is one of the major bioactive components identified from C. militaris. Thus, C. militaris and COR have attracted extensive attention. In this study, chemical synthetic methods and the biosynthesis pathway of COR were reviewed. As commercially COR was mainly isolated from C. militaris fermentation, the optimizations for liquid and solid fermentation and genetic modifications of C. militaris to increase COR content were also summarized. Moreover, the research progress of genetic modifications of C. militaris and methods for separation and purification COR were introduced. Finally, the existing problems and future research direction of C. militaris were discussed. This study provides a reference for the production of COR in the future.
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Affiliation(s)
- Li Wang
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Science, Jiangxi Science & Technology Normal University, Nanchang 330013, China; (L.W.); (H.Y.)
| | - Huanhuan Yan
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Science, Jiangxi Science & Technology Normal University, Nanchang 330013, China; (L.W.); (H.Y.)
| | - Bin Zeng
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Science, Jiangxi Science & Technology Normal University, Nanchang 330013, China; (L.W.); (H.Y.)
- College of Pharmacy, Shenzhen Technology University, Shenzhen 518118, China
- Correspondence: (B.Z.); (Z.H.); Tel.: +86-13755679856 (B.Z.); +86-15797865372 (Z.H.)
| | - Zhihong Hu
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Science, Jiangxi Science & Technology Normal University, Nanchang 330013, China; (L.W.); (H.Y.)
- Correspondence: (B.Z.); (Z.H.); Tel.: +86-13755679856 (B.Z.); +86-15797865372 (Z.H.)
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Rabie AM. Potent Inhibitory Activities of the Adenosine Analogue Cordycepin on SARS-CoV-2 Replication. ACS OMEGA 2022; 7:2960-2969. [PMID: 35071937 PMCID: PMC8767658 DOI: 10.1021/acsomega.1c05998] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 12/14/2021] [Indexed: 01/18/2023]
Abstract
![]()
Nucleoside analogues
are among the most successful bioactive classes
of druglike compounds in pharmaceutical chemistry as they are well-known
for their numerous effective bioactivities in humans, especially as
antiviral and anticancer agents. Coronavirus disease 2019 (COVID-19)
is still untreatable, with its causing virus, the severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2), continuing to wreak havoc on
the ground everywhere. This complicated international situation urged
all concerned scientists, including medicinal chemists and drug discoverers,
to search for a potent anti-COVID-19 drug. Cordycepin (3′-deoxyadenosine)
is a known natural adenosine analogue of fungal origin, which could
also be synthetically produced. This bioactive phytochemical compound
is characterized by several proven strong pharmacological actions
that may effectively contribute to the comprehensive treatment of
COVID-19, with the antiviral activities being the leading ones. Some
new studies predicted the possible inhibitory affinities of cordycepin
against the principal SARS-CoV-2 protein targets (e.g., SARS-CoV-2 spike (S) protein, main protease (Mpro) enzyme,
and RNA-dependent RNA polymerase (RdRp) enzyme) based on the computational
approach. Interestingly, the current research showed, for the first
time, that cordycepin is able to potently inhibit the multiplication
of the new resistant strains of SARS-CoV-2 with a very minute in vitro anti-SARS-CoV-2 EC50 of about 2 μM,
edging over both remdesivir and its active metabolite GS-441524. The
ideal pharmacophoric features of the cordycepin molecule render it
a typical inhibitor of SARS-CoV-2 replication, with its flexible structure
open for most types of derivatization in the future. Briefly, the
current findings further support and suggest the repurposing possibility
of cordycepin against COVID-19 and greatly encourage us to confidently
and rapidly begin its preclinical/clinical evaluations for the comprehensive
treatment of COVID-19.
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Affiliation(s)
- Amgad M. Rabie
- Dr. Amgad Rabie’s Research Lab. for Drug Discovery (DARLD), Mansoura 35511, Egypt
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
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Bibi S, Hasan MM, Wang YB, Papadakos SP, Yu H. Cordycepin as a Promising Inhibitor of SARS-CoV-2 RNA dependent RNA polymerase (RdRp). Curr Med Chem 2021; 29:152-162. [PMID: 34420502 DOI: 10.2174/0929867328666210820114025] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/21/2021] [Accepted: 06/28/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND SARS-CoV-2, which emerged in Wuhan, China, is a new global threat that has killed millions of people and continues to do so. This pandemic has not only threatened human life but has also triggered economic downturns across the world. Researchers have made significant strides in discovering molecular insights into SARS-CoV-2 pathogenesis and developing vaccines, but there is still no successful cure for SARS-CoV-2 infected patients. OBJECTIVE The present study has proposed a drug-repositioning pipeline for the design and discovery of an effective fungal-derived bioactive metabolite as a drug candidate against SARS-CoV-2. METHODS Fungal derivative "Cordycepin" was selected for this study to investigate the inhibitory properties against RNA-dependent RNA polymerase (RdRp) (PDB ID: 6M71) of SARS-CoV-2. The pharmacological profile, intermolecular interactions, binding energy, and stability of the compound were determined utilizing cheminformatic approaches. Subsequently, molecular dynamic simulation was performed to better understand the binding mechanism of cordycepin to RdRp. RESULTS The pharmacological data and retrieved molecular dynamics simulations trajectories suggest excellent drug-likeliness and greater structural stability of cordycepin, while the catalytic residues (Asp760, Asp761), as well as other active site residues (Trp617, Asp618, Tyr619, Trp800, Glu811) of RdRp, showed better stability during the overall simulation span. CONCLUSION Promising results of pharmacological investigation along with molecular simulations revealed that cordycepin exhibited strong inhibitory potential against SARS-CoV-2 polymerase enzyme (RdRp). Hence, cordycepin should be highly recommended to test in a laboratory to confirm its inhibitory potential against the SARS-CoV-2 polymerase enzyme (RdRp).
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Affiliation(s)
- Shabana Bibi
- Yunnan Herbal Laboratory, College of Ecology and Environmental Sciences, Yunnan University, Kunming 650091, Yunnan. China
| | - Mohammad Mehedi Hasan
- Department of Biochemistry and Molecular Biology, Faculty of Life Science, Mawlana Bhashani Science and Technology University, Tangail 1902. Bangladesh
| | - Yuan-Bing Wang
- Yunnan Herbal Laboratory, College of Ecology and Environmental Sciences, Yunnan University, Kunming 650091, Yunnan. China
| | - Stavros P Papadakos
- First Department of Pathology, School of Medicine, National and Kapodistrian University of Athens (NKUA), Athens. Greece
| | - Hong Yu
- Yunnan Herbal Laboratory, College of Ecology and Environmental Sciences, Yunnan University, Kunming 650091, Yunnan. China
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Ryu E, Son M, Lee M, Lee K, Cho JY, Cho S, Lee SK, Lee YM, Cho H, Sung GH, Kang H. Cordycepin is a novel chemical suppressor of Epstein-Barr virus replication. Oncoscience 2014; 1:866-881. [PMID: 25621301 PMCID: PMC4303894 DOI: 10.18632/oncoscience.110] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 12/14/2014] [Indexed: 12/12/2022] Open
Abstract
Cordyceps species are known to produce numerous active components and are used for diverse medicinal purposes because of their varied physiological activities, including their ability to protect the liver from damage as well as their anticancer, antidepressant, anti-inflammatory, hypoglycemic, antimicrobial effects. Cordycepin, an adenosine derivative, differs from adenosine in that its ribose lacks an oxygen atom at the 3′ position. Several research groups have reported that cordycepin has antiviral activity against several viruses including influenza virus, plant viruses, human immunodeficiency virus(HIV), murine leukemia virus, and Epstein-Barr virus (EBV). In this study, we identify the epigenetic mechanisms by which cordycepin exerts its anti-gammaherpesvirus effects. We show that cordycepin possesses antitumor and antiviral activity against gastric carcinoma and EBV, respectively. A comparison of the CD50 values of cordycepin and its analogs showed that the lack of a 2′-hydroxyl group in cordycepin was critical for its relatively potent cytotoxicity. Cordycepin treatment decreased the rate of early apoptosis in SNU719 cells by up to 64%, but increased late apoptosis/necrosis by up to 31%. Interestingly, cordycepin increased BCL7A methylation in SNU719 cells by up to 58% and decreased demethylation by up to 37%. Consistent with these changes in methylation, cordycepin treatment significantly downregulated most EBV genes tested. Under the same conditions, cordycepin significantly decreased the frequency of Q and F promoter usage, and H3K4me3 histone enrichment was significantly reduced at several important EBV genomic loci. Extracellular and intracellular EBV genome copy numbers were reduced by up to 55% and 30%, respectively, in response to 125 μM cordycepin treatment. Finally, cordycepin significantly suppressed the transfer of EBV from LCL-EBV-GFP to AGS cells, indicating that EBV infection of gastric epithelial cells was inhibited. These results suggest that cordycepin has antiviral and antitumor activities against gammaherpesviruses and host cells latently infected with virus.
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Affiliation(s)
- Eunhyun Ryu
- College of Pharmacy and Institute of microorganisms, Kyungpook National University, Daegu, Republic of Korea
| | - Myoungki Son
- College of Pharmacy and Institute of microorganisms, Kyungpook National University, Daegu, Republic of Korea
| | - Minjung Lee
- College of Pharmacy and Institute of microorganisms, Kyungpook National University, Daegu, Republic of Korea
| | - Kanghyo Lee
- Mushroom Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Eumseong, Republic of Korea
| | - Jae Youl Cho
- Department of Genetic Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Sungchan Cho
- Targeted Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongwon, Chungbuk, Republic of Korea
| | - Suk Kyeong Lee
- Research Institute of Immunobiology, Department of Biomedical Sciences, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - You Mie Lee
- College of Pharmacy and Institute of microorganisms, Kyungpook National University, Daegu, Republic of Korea
| | - Hyosun Cho
- College of Pharmacy, Duksung Women's University, Seoul, Republic of Korea
| | - Gi-Ho Sung
- Institute for Bio-Medical Convergence, International St. Mary's Hospital, College of Medicine, Catholic Kwangdong University, Incheon, Republic of Korea
| | - Hyojeung Kang
- College of Pharmacy and Institute of microorganisms, Kyungpook National University, Daegu, Republic of Korea
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Hurtenbach U, Morgenstern F, Bennett D. Induction of tolerance in vitro by autologous murine testicular cells. J Exp Med 1980; 151:827-38. [PMID: 6445394 PMCID: PMC2185828 DOI: 10.1084/jem.151.4.827] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
We have investigated the regulation of self tolerance in mice by examining lymphocyte reactivity in vitro against two subpopulations of autologous testicular cells: germ cells that were derived from the seminiferous tubules, and interstitial somatic cells. In the presence of germ cells, lymphocyte proliferation was strongly reduced. In contrast, somatic interstitial cells stimulated lymphocyte proliferation. In both cases, reactive lymphocytes were mostly T cells. Suppressor T cells activated by autologous germ cells were nonspecific and capable of inhibiting lymphocyte proliferation against autologous and allogeneic somatic testicular cells as well as against allogeneic spleen cells. Suppression was abrogated after treatment of the responder lymphocytes with anti-Ly-2.2 serum plus complement. Lymphocyte proliferation by autologous interstitial cells was considerably reduced, but not completely abolished, by complement-dependent lysis with anti-Thy-1.2 serum. This may indicate the participation in proliferation of a lymphoid cell population other than T cells.
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Wekerle H. Immunological T-cell memory in the in vitro-induced experimental autoimmune orchitis: specificity of the reaction and tissue distribution of the autoantigens. J Exp Med 1978; 147:233-50. [PMID: 304879 PMCID: PMC2184096 DOI: 10.1084/jem.147.1.233] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Immunological memory has been induced in vitro against testicular autoantigens by priming normal rat T lymphocytes against autologous testis cells, and by permitting the isolated blast cells to revert back to small secondary lymphocytes (secondary EAO cells) in the absence of the priming antigen. The secondary EAO cells vigorously respond in a secondary response when reconfronted with syngeneic testis or lymphoid cells. Their responsiveness to nonself stimulator cells is, however, reduced. Secondary cells derived from concanavalin A-stimulated blasts, do not show that pattern of specificity. The specificity of the secondary EAO cells is definite, and cannot be affected by further culture on allogeneic fibroblasts, which are antigenic for unprimed T lymphocytes. At least part of the autoantigens are determined by the major histocompatibility gene complex (MHC). Factors provided by the culture system do not appear to determine the specificity of this reaction. Only minor cell populations can restimulate secondary EAO cells. One of these populations is presumably phage-like cells within the lymphoid populations can elicit a secondary EAO response. Thus, the autoantigens relevant in the secondary EAO response are either MHC antigens restricted to these testicular and lymphoid subpopulations, or MHC antigens recognized in conjunction with organ-specific non-MHC determinants.
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10
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Hirsch MS, Proffitt MR, Black PH. Autoimmunity, oncornaviruses, and lymphomagenesis. CONTEMPORARY TOPICS IN IMMUNOBIOLOGY 1977; 6:209-27. [PMID: 17512 DOI: 10.1007/978-1-4684-3051-6_7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The interactions between aberrant immune responses and C-type oncornaviruses in mice are complex. These viruses may be activated during certain immune responses, e.g., histocompatibility reactions, in the face of chronic immunosuppression. Oncornaviruses, themselves, may induce autoaggressive cell-mediated responses in certain lymphoid subpopulations, and these autoimmune reactions may be important in subsequent lymphomagenesis. Parallel events may occur in other animal models, e.g., the NZB mouse, and in certain human disorders, e.g., Sjögren's syndrome, systemic lupus erythematosus, and myasthenia gravis.
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Okazaki E, Aoki T, De Kozlowski SJ. AKR leukemia-specific surface antigens acquired by malignant transformation: their common and individual specificities. Int J Cancer 1976; 17:640-6. [PMID: 57936 DOI: 10.1002/ijc.2910170513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antisera against five newly established AKR spontaneous leukemias (KSL) prepared by immunization of KSL cells in (C57B1/6 X C3Hf/He)F1 mice were preabsorbed with non-leukemic AKR lymphoid cells to remove antibodies against virus-associated surface antigens and alloantigens. In absorption tests the antisera showed no cross-reaction by immunofluorescence microscopy with thymocyte, fetal, male-specific H-Y, E and X.1 antigens; with known Gross murine leukemia virus-associated antigens; or with cell surface antigens on Friend, Moloney and Rauscher virus-induced tumors. It was thus shown that the antigens detected were leukemia-specific, were acquired by malignant transformation, and consisted of two types: (1) a common antigen in all the KSL, and (2) individual antigens found in four of the KSL which showed distinct patterns of partial cross-reactivity with the other KSL.
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Haas M, Hilgers J. In vitro infection of lymphoid cells by thymotropic radiation leukemia virus grown in vitro. Proc Natl Acad Sci U S A 1975; 72:3546-50. [PMID: 171665 PMCID: PMC433032 DOI: 10.1073/pnas.72.9.3546] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Murine lymphoid cells were infected in vitro with purified leukemogenic radiation leukemia virus (RadLV) produced by virus-induced lymphoblast cell lines. Thymocytes were shown to be highly susceptible to infection by the virus, whereas murine or other fibroblasts were refractory to it. Murine bone marrow and spleen cells were shown to be much less sensitive to infection by this thymotropic RadLV. By comparison, a B-tropic RadLV isolate (RadLV), propagated on a mouse fibroblast cell line, was noninfectious for lymphoid cells but infected fibroblasts. A correlation was shown to exist between in vitro infection of thymocytes, as assayed by immunofluorescence, and in vivo leukemogenicity of the thymotropic RadLV. This constitutes a rapid in vitro test for in vivo leukemogenicity of a natural lymphatic leukemia virus.
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Moroni C, Schumann G, Robert-Guroff M, Suter ER, Martin D. Induction of endogenous murine C-type virus in spleen cell cultures treated with mitogens and 5-bromo-2'-deoxyuridine. Proc Natl Acad Sci U S A 1975; 72:535-8. [PMID: 47632 PMCID: PMC432347 DOI: 10.1073/pnas.72.2.535] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In short-term cultures of BALB/c spleen cells, treatment with a combination of 5-bromo-2'-deoxyuridine (BrdU) and either lipopolysaccharide W. Escherichia coli or concanavalin A resulted in release of C-type virus into the medium. Only lipopolysaccharide induced virus release when given alone. This could be potentiated by a combined treatment with BrdU. In contrast, phytohemagglutinin at mitogenic concentration had no effect with or without BrdU, suggesting that inducibility may vary between various mitogen-responsive spleen cell populations. In AKR mice, spontaneous virus release was detectable in nonstimulated spleen cell cultures. This could be potentiated by lipopolysaccharide, whereas no further increase occurred upon additional BrdU treatment. The induced viruses had C-type characteristics in that they contained reverse transcriptase that could be distinguished from cellular enzymes by template-primer preference experiments. Furthermore, the enzyme activities were particle-associated, banding in isopycnic sucrose gradients at 1.15-1.17 g/cm-3. The presence of C-type viruses was confirmed by electron microscopy.
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