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Pampeno C, Opp S, Hurtado A, Meruelo D. Sindbis Virus Vaccine Platform: A Promising Oncolytic Virus-Mediated Approach for Ovarian Cancer Treatment. Int J Mol Sci 2024; 25:2925. [PMID: 38474178 PMCID: PMC10932354 DOI: 10.3390/ijms25052925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/30/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
This review article provides a comprehensive overview of a novel Sindbis virus vaccine platform as potential immunotherapy for ovarian cancer patients. Ovarian cancer is the most lethal of all gynecological malignancies. The majority of high-grade serous ovarian cancer (HGSOC) patients are diagnosed with advanced disease. Current treatment options are very aggressive and limited, resulting in tumor recurrences and 50-60% patient mortality within 5 years. The unique properties of armed oncolytic Sindbis virus vectors (SV) in vivo have garnered significant interest in recent years to potently target and treat ovarian cancer. We discuss the molecular biology of Sindbis virus, its mechanisms of action against ovarian cancer cells, preclinical in vivo studies, and future perspectives. The potential of Sindbis virus-based therapies for ovarian cancer treatment holds great promise and warrants further investigation. Investigations using other oncolytic viruses in preclinical studies and clinical trials are also presented.
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Pampeno C, Hurtado A, Opp S, Meruelo D. Channeling the Natural Properties of Sindbis Alphavirus for Targeted Tumor Therapy. Int J Mol Sci 2023; 24:14948. [PMID: 37834397 PMCID: PMC10573789 DOI: 10.3390/ijms241914948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/21/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
Sindbis alphavirus vectors offer a promising platform for cancer therapy, serving as valuable models for alphavirus-based treatment. This review emphasizes key studies that support the targeted delivery of Sindbis vectors to tumor cells, highlighting their effectiveness in expressing tumor-associated antigens and immunomodulating proteins. Among the various alphavirus vectors developed for cancer therapy, Sindbis-vector-based imaging studies have been particularly extensive. Imaging modalities that enable the in vivo localization of Sindbis vectors within lymph nodes and tumors are discussed. The correlation between laminin receptor expression, tumorigenesis, and Sindbis virus infection is examined. Additionally, we present alternative entry receptors for Sindbis and related alphaviruses, such as Semliki Forest virus and Venezuelan equine encephalitis virus. The review also discusses cancer treatments that are based on the alphavirus vector expression of anti-tumor agents, including tumor-associated antigens, cytokines, checkpoint inhibitors, and costimulatory immune molecules.
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Opp S, Hurtado A, Pampeno C, Lin Z, Meruelo D. Potent and Targeted Sindbis Virus Platform for Immunotherapy of Ovarian Cancer. Cells 2022; 12:77. [PMID: 36611875 PMCID: PMC9818975 DOI: 10.3390/cells12010077] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
Our laboratory has been developing a Sindbis viral (SV) vector platform for treatments of ovarian and other types of cancers. In this study we show that SV.IL-12 combined with an agonistic OX40 antibody can eliminate ovarian cancer in a Mouse Ovarian Surface Epithelial Cell Line (MOSEC) model and further prevent tumors in mice rechallenged with tumor cells after approximately 5 months. Treatment efficacy is shown to be dependent upon T-cells that are transcriptionally and metabolically reprogramed. An influx of immune cells to the tumor microenvironment occurs. Combination of sequences encoding both IL-12 and anti-OX40 into a single SV vector, SV.IgGOX40.IL-12, facilitates the local delivery of immunoregulatory agents to tumors enhancing the anti-tumor response. We promote SV.IgGOX40.IL-12 as a safe and effective therapy for multiple types of cancer.
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Scaglione A, Opp S, Hurtado A, Lin Z, Pampeno C, Noval MG, Thannickal SA, Stapleford KA, Meruelo D. Combination of a Sindbis-SARS-CoV-2 Spike Vaccine and αOX40 Antibody Elicits Protective Immunity Against SARS-CoV-2 Induced Disease and Potentiates Long-Term SARS-CoV-2-Specific Humoral and T-Cell Immunity. Front Immunol 2021; 12:719077. [PMID: 34394127 PMCID: PMC8359677 DOI: 10.3389/fimmu.2021.719077] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/13/2021] [Indexed: 12/17/2022] Open
Abstract
The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 is a major global public threat. Currently, a worldwide effort has been mounted to generate billions of effective SARS-CoV-2 vaccine doses to immunize the world's population at record speeds. However, there is still a demand for alternative effective vaccines that rapidly confer long-term protection and rely upon cost-effective, easily scaled-up manufacturing. Here, we present a Sindbis alphavirus vector (SV), transiently expressing the SARS-CoV-2 spike protein (SV.Spike), combined with the OX40 immunostimulatory antibody (αOX40) as a novel, highly effective vaccine approach. We show that SV.Spike plus αOX40 elicits long-lasting neutralizing antibodies and a vigorous T-cell response in mice. Protein binding, immunohistochemical, and cellular infection assays all show that vaccinated mice sera inhibits spike functions. Immunophenotyping, RNA Seq transcriptome profiles, and metabolic analysis indicate a reprogramming of T cells in vaccinated mice. Activated T cells were found to mobilize to lung tissue. Most importantly, SV.Spike plus αOX40 provided robust immune protection against infection with authentic coronavirus in transgenic mice expressing the human ACE2 receptor (hACE2-Tg). Finally, our immunization strategy induced strong effector memory response, potentiating protective immunity against re-exposure to SARS-CoV-2 spike protein. Our results show the potential of a new Sindbis virus-based vaccine platform to counteract waning immune response, which can be used as a new candidate to combat SARS-CoV-2. Given the T-cell responses elicited, our vaccine is likely to be effective against variants that are proving challenging, as well as serve as a platform to develop a broader spectrum pancoronavirus vaccine. Similarly, the vaccine approach is likely to be applicable to other pathogens.
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Scaglione A, Opp S, Hurtado A, Lin Z, Pampeno C, Noval MG, Thannickal SA, Stapleford KA, Meruelo D. Combination of a Sindbis-SARS-CoV-2 spike vaccine and αOX40 antibody elicits protective immunity against SARS-CoV-2 induced disease and potentiates long-term SARS-CoV-2-specific humoral and T-cell immunity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.05.28.446009. [PMID: 34075383 PMCID: PMC8168399 DOI: 10.1101/2021.05.28.446009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 is a major global public threat. Currently, a worldwide effort has been mounted to generate billions of effective SARS-CoV-2 vaccine doses to immunize the world's population at record speeds. However, there is still demand for alternative effective vaccines that rapidly confer long-term protection and rely upon cost-effective, easily scaled-up manufacturing. Here, we present a Sindbis alphavirus vector (SV), transiently expressing the SARS-CoV-2 spike protein (SV.Spike), combined with the OX40 immunostimulatory antibody (αOX40) as a novel, highly effective vaccine approach. We show that SV.Spike plus αOX40 elicits long-lasting neutralizing antibodies and a vigorous T-cell response in mice. Protein binding, immunohistochemical and cellular infection assays all show that vaccinated mice sera inhibits spike functions. Immunophenotyping, RNA Seq transcriptome profiles and metabolic analysis indicate a reprogramming of T-cells in vaccinated mice. Activated T-cells were found to mobilize to lung tissue. Most importantly, SV.Spike plus αOX40 provided robust immune protection against infection with authentic coronavirus in transgenic mice expressing the human ACE2 receptor (hACE2-Tg). Finally, our immunization strategy induced strong effector memory response, potentiating protective immunity against re-exposure to SARS-CoV-2 spike protein. Our results show the potential of a new Sindbis virus-based vaccine platform to counteract waning immune response that can be used as a new candidate to combat SARS-CoV-2. Given the strong T-cell responses elicited, our vaccine is likely to be effective against variants that are proving challenging, as well as, serve as a platform to develop a broader spectrum pancoronavirus vaccine. Similarly, the vaccine approach is likely to be applicable to other pathogens.
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Scherwitzl I, Opp S, Hurtado AM, Pampeno C, Loomis C, Kannan K, Yu M, Meruelo D. Sindbis Virus with Anti-OX40 Overcomes the Immunosuppressive Tumor Microenvironment of Low-Immunogenic Tumors. Mol Ther Oncolytics 2020; 17:431-447. [PMID: 32478167 PMCID: PMC7251545 DOI: 10.1016/j.omto.2020.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 04/29/2020] [Indexed: 01/03/2023] Open
Abstract
Despite remarkable responses to cancer immunotherapy in a subset of patients, many patients remain resistant to therapies. It is now clear that elevated levels of tumor-infiltrating T cells as well as a systemic anti-tumor immune response are requirements for successful immunotherapies. However, the tumor microenvironment imposes an additional resistance mechanism to immunotherapy. We have developed a practical and improved strategy for cancer immunotherapy using an oncolytic virus and anti-OX40. This strategy takes advantage of a preexisting T cell immune repertoire in vivo, removing the need to know about present tumor antigens. We have shown in this study that the replication-deficient oncolytic Sindbis virus vector expressing interleukin-12 (IL-12) (SV.IL12) activates immune-mediated tumor killing by inducing OX40 expression on CD4 T cells, allowing the full potential of the agonistic anti-OX40 antibody. The combination of SV.IL12 with anti-OX40 markedly changes the transcriptome signature and metabolic program of T cells, driving the development of highly activated terminally differentiated effector T cells. These metabolically reprogrammed T cells demonstrate enhanced tumor infiltration capacity as well as anti-tumor activity capable of overcoming the repressive tumor microenvironment. Our findings identify SV.IL12 in combination with anti-OX40 to be a novel and potent therapeutic strategy that can cure multiple types of low-immunogenic solid tumors.
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Scherwitzl I, Hurtado A, Pierce CM, Vogt S, Pampeno C, Meruelo D. Systemically Administered Sindbis Virus in Combination with Immune Checkpoint Blockade Induces Curative Anti-tumor Immunity. MOLECULAR THERAPY-ONCOLYTICS 2018; 9:51-63. [PMID: 29988525 PMCID: PMC6026467 DOI: 10.1016/j.omto.2018.04.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 04/28/2018] [Indexed: 12/19/2022]
Abstract
Oncolytic viruses represent a promising form of cancer immunotherapy. We investigated the potential of Sindbis virus (SV) for the treatment of solid tumors expressing the human cancer testis antigen NYESO-1. NYESO-1 is an immunogenic antigen frequently expressed in numerous cancers, such as ovarian cancer. We show that SV expressing the tumor-associated antigen NYESO-1 (SV-NYESO1) acts as an immunostimulatory agent, inducing systemic and rapid lymphocyte activation, leading to a pro-inflammatory environment. SV-NYESO1 treatment combined with anti-programmed death 1 (anti-PD-1) markedly augmented the anti-tumor immunity in mice over the course of treatment, resulting in an avid systemic and intratumoral immune response. This response involved reduced presence of granulocytic myeloid-derived suppressor cells in tumors and an increase in the activation of splenic and tumor-infiltrating T cells. Combined therapy also induced enhanced cytotoxic activity of T cells against NYESO-1-expressing tumors. These results were in line with an observed inverse correlation between T cell activation and tumor growth. Finally, we show that combined therapy resulted in complete clearance of NYESO-1-expressing tumors in vivo and led to long-term protection against recurrences. These findings provide a rationale for clinical studies of SV-NYESO1 combined with immune checkpoint blockade anti-PD-1 to be used in the treatment of NYESO-1-expressing tumors.
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Pampeno C, Derkatch IL, Meruelo D. Interaction of human laminin receptor with Sup35, the [PSI⁺] prion-forming protein from S. cerevisiae: a yeast model for studies of LamR interactions with amyloidogenic proteins. PLoS One 2014; 9:e86013. [PMID: 24416454 PMCID: PMC3885751 DOI: 10.1371/journal.pone.0086013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 12/09/2013] [Indexed: 12/25/2022] Open
Abstract
The laminin receptor (LamR) is a cell surface receptor for extracellular matrix laminin, whereas the same protein within the cell interacts with ribosomes, nuclear proteins and cytoskeletal fibers. LamR has been shown to be a receptor for several bacteria and viruses. Furthermore, LamR interacts with both cellular and infectious forms of the prion protein, PrP(C) and PrP(Sc). Indeed, LamR is a receptor for PrP(C). Whether LamR interacts with PrP(Sc) exclusively in a capacity of the PrP receptor, or LamR specifically recognizes prion determinants of PrP(Sc), is unclear. In order to explore whether LamR has a propensity to interact with prions and amyloids, we examined LamR interaction with the yeast prion-forming protein, Sup35. Sup35 is a translation termination factor with no homology or functional relationship to PrP. Plasmids expressing LamR or LamR fused with the green fluorescent protein (GFP) were transformed into yeast strain variants differing by the presence or absence of the prion conformation of Sup35, respectively [PSI⁺] and [psi⁻]. Analyses by immunoprecipitation, centrifugal fractionation and fluorescent microscopy reveal interaction between LamR and Sup35 in [PSI⁺] strains. The presence of [PSI⁺] promotes LamR co-precipitation with Sup35 as well as LamR aggregation. In [PSI⁺] cells, LamR tagged with GFP or mCherry forms bright fluorescent aggregates that co-localize with visible [PSI⁺] foci. The yeast prion model will facilitate studying the interaction of LamR with amyloidogenic prions in a safe and easily manipulated system that may lead to a better understanding and treatment of amyloid diseases.
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Pampeno C, Hurtado A, Meruelo D. ATM kinase is activated by sindbis viral vector infection. Virus Res 2012; 166:97-102. [PMID: 22475743 DOI: 10.1016/j.virusres.2012.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 03/12/2012] [Accepted: 03/13/2012] [Indexed: 11/27/2022]
Abstract
Sindbis virus is a prototypic member of the Alphavirus genus, Togaviridae family. Sindbis replication results in cellular cytotoxicity, a feature that has been exploited by our laboratory for treatment of in vivo tumors. Understanding the interactions between Sindbis vectors and the host cell can lead to better virus production and increased efficacy of gene therapy vectors. Here we present studies investigating a possible cellular response to genotoxic effects of Sindbis vector infection. The Ataxia Telangiectasia Mutated (ATM) kinase, a sentinel against genomic and cellular stress, was activated by Sindbis vector infection at 3h post infection. ATM substrates, Mcm3 and the γH2AX histone, were subsequently phosphorylated, however, substrates involved with checkpoint arrest of DNA replication, p53, Chk1 and Chk2, were not differentially phosphorylated compared with uninfected cells. The ATM response suggests nuclear pertubation, resulting from cessation of host protein synthesis, as an early event in Sindbis vector infection.
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Hurtado A, Tseng JC, Boivin C, Levin B, Yee H, Pampeno C, Meruelo D. Identification of amino acids of Sindbis virus E2 protein involved in targeting tumor metastases in vivo. Mol Ther 2005; 12:813-23. [PMID: 16109508 DOI: 10.1016/j.ymthe.2005.06.476] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Revised: 06/23/2005] [Accepted: 06/27/2005] [Indexed: 11/20/2022] Open
Abstract
Previous studies conducted in our laboratory with Sindbis viral vectors in animal models demonstrated excellent in vivo targeting of tumor cells and significant reduction of metastatic implant size. To explore the influence of Sindbis strain on these factors, we constructed new plasmids from the wild-type Ar-339 Sindbis virus strain and compared their sequences. We found differences in the replicase and envelope proteins between JT, HRSP, and Ar-339 sequences. We made chimeras combining both strains and studied their efficiency in SCID mice bearing tumor xenograft using IVIS in vivo imaging techniques. We found that JT envelope proteins targeted tumors more efficiently than those of Ar-339, while the Ar-339 replicase showed increased efficacy in tumor reduction. To determine which residues are responsible for tumor targeting, we made mutants of Ar-339 E2 envelope protein and tested them by IVIS imaging in ES-2 tumor-bearing and tumor-free mice. The change of only one amino acid from E70 to K70 in Ar-339 E2 suppressed the ability to target metastatic tumor implants in mice. A K70 and V251 double E2 mutant did not reverse the loss of targeting capability. Only the mutant with JT E2 and Ar-339 helper targeted tumor, though with less intensity.
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Tseng JC, Levin B, Hirano T, Yee H, Pampeno C, Meruelo D. In vivo antitumor activity of Sindbis viral vectors. J Natl Cancer Inst 2002; 94:1790-802. [PMID: 12464651 DOI: 10.1093/jnci/94.23.1790] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Sindbis virus, a blood-borne virus transmitted by mosquitoes, has been used as a vector to efficiently express exogenous genes in vitro and in vivo and to induce apoptosis. Because Sindbis virus infects mammalian cells by interacting with the high-affinity laminin receptors, which are expressed at higher levels in several human cancers than in normal cells, we determined whether a Sindbis viral vector could be used to target cancers in vivo. METHODS C.B-17-SCID mice with established xenografts were given daily intraperitoneal injections of the Sindbis viral vector SinRep/LacZ containing the bacterial beta-galactosidase gene. Control mice were untreated or received injections with phosphate-buffered saline. Tumor size was measured daily. Expression of beta-galactosidase and Factor VIII (a marker for endothelial cells) was determined by immunohistochemical staining of tumor sections. Apoptosis was analyzed by TUNEL (terminal deoxynucleotidyl transferase [TdT]-mediated dUTP nick end labeling) staining. C.B-17-SCID beige mice, which lack natural killer (NK) cells, were used to assess the importance of NK cells in antitumor efficacy of Sindbis viral vectors. RESULTS Tumors from mice treated with SinRep/LacZ were statistically significantly smaller than tumors from control mice. This effect was observed for tumor xenografts derived from BHK (kidney, hamster), LS174T (colon, human), HT29 (colon, human), and CFPAC (pancreas, human) cells. Expression of beta-galactosidase co-localized with that of Factor VIII in tumor sections. Tumors from SinRep/LacZ-treated mice contained more apoptotic cells than tumors from control mice. Complete tumor regression was observed in three of five C.B-17-SCID mice but in none of five C.B-17-SCID beige mice treated with SinRep/LacZ. CONCLUSION Sindbis viral vectors efficiently targeted tumors in vivo, were apparently delivered through the circulation, and were more effective in the presence of NK cells.
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Choi JW, Pampeno C, Vukmanovic S, Meruelo D. Characterization of the transcriptional expression of Notch-1 signaling pathway members, Deltex and HES-1, in developing mouse thymocytes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2002; 26:575-588. [PMID: 12031417 DOI: 10.1016/s0145-305x(01)00095-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The Notch transmembrane protein is involved in a broad range of different developmental pathways in vertebrates and invertebrates. Targeted thymocyte expression of the Notch-1 intracellular domain has been shown to affect lineage commitment decisions such as those involving T cell vs. B cell, thymocyte alpha beta vs. gamma delta TCR, as well as CD4 vs. CD8 thymocyte commitment. In this paper, we quantitatively characterize thymocyte RNA expression of two purported transcriptional markers of Notch-1 signaling activity, Deltex and HES-1. Using a semiquantitative RTPCR approach, we show that both Deltex and HES-1 transcriptional levels are developmentally regulated as thymocytes mature from the earliest CD4/CD8 double negative thymocyte stage, through the intermediate CD4/CD8 double positive stage, and finally to the mature CD4 or CD8 single positive stage. Deltex and HES-1, despite both being transcriptional markers of Notch-1 activity, express different patterns of transcriptional activity among the thymocyte subsets. Neither treatment with combined (alpha CD3)/(alpha CD28) antibodies nor the combination of the phorbol ester PMA and calcium ionophore ionomycin affects expression of Deltex in immature thymocytes; however, PMA/ionomycin treatment does downregulate expression of HES-1, an affect mostly mediated by ionomycin. Finally, a difference in HES-1 expression is seen between CD4/CD8 double positive thymocytes isolated from wild-type vs. MHC class I/II deficient mice, suggesting that Notch-1 activity is modulated during in vivo TCR/MHC-ligand selection events.
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Houlden BA, Matis LA, Cron RQ, Widacki SM, Brown GD, Pampeno C, Meruelo D, Bluestone JA. A TCR gamma delta cell recognizing a novel TL-encoded gene product. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1989; 54 Pt 1:45-55. [PMID: 2576978 DOI: 10.1101/sqb.1989.054.01.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Pampeno C, Meruelo D. Genomic organization of the mouse Tla locus: study of an endogenous retroviruslike locus reveals polymorphisms related to different Tla haplotypes. Immunogenetics 1988; 28:247-54. [PMID: 2901400 DOI: 10.1007/bf00345501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A retrovirus element (TLev1) is located within the Thymus leukemia antigen (Tla) locus of the C57BL/10 mouse major histocompatibility complex. Low-copy probes have been isolated from sequences flanking the TLev1 integration site to examine the distribution of TLev1 among inbred mouse strains having genotypically determined variations in TL-antigen expression. It was found that the low-copy probes cross-hybridize to regions within the Tla locus in a genotype-specific manner. Although a strong association was found between TL mouse strains and TLev1, the presence or absence of the TLev1 locus did not exclusively correlate with expression or nonexpression of TL antigens. Analysis of different Mus subspecies indicates that TLev1 integrated into a common ancestor of the species Mus musculus. It is suggested that the loss of the TLev1 locus from certain mouse genomes reflects evolutionary rearrangements in the TL region; the resulting diversity may relate to the differential expression of TL antigens among mouse strains. The probes described here provide a useful tool for examining the genomic expansions and contractions which have occurred during the evolution of the Tla locus.
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Meruelo D, Kornreich R, Rossomando A, Pampeno C, Boral A, Silver JL, Buxbaum J, Weiss EH, Devlin JJ, Mellor AL. Lack of class I H-2 antigens in cells transformed by radiation leukemia virus is associated with methylation and rearrangement of H-2 DNA. Proc Natl Acad Sci U S A 1986; 83:4504-8. [PMID: 3012570 PMCID: PMC323762 DOI: 10.1073/pnas.83.12.4504] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Transformation of murine thymocytes by radiation leukemia virus is associated with reduced expression of the class I antigens encoded in the major histocompatibility complex (MHC) and increased methylation and altered restriction enzyme patterns of MHC DNA. These changes may play a role in host susceptibility to virus-induced leukemogenesis and accord with the notion that viral genomes play a regulatory function when they integrate adjacent to histocompatibility genes.
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Meruelo D, Kornreich R, Rossomando A, Pampeno C, Mellor AL, Weiss EH, Flavell RA, Pellicer A. Murine leukemia virus sequences are encoded in the murine major histocompatibility complex. Proc Natl Acad Sci U S A 1984; 81:1804-8. [PMID: 6324216 PMCID: PMC345009 DOI: 10.1073/pnas.81.6.1804] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The studies reported here localize murine leukemia viral sequences to the TL region of the major histocompatibility complex, H-2. We examined a battery of 38 cosmids, isolated from two large genomic libraries constructed from C57BL/10 spleen DNA, that define 25 class I gene sequences. The viral probes used hybridized with only four cosmids, containing overlapping mouse sequences, that define four class I gene-related sequences in a region of 90 kilobases of DNA. The data show that two distinct viral envelope sequences are contained in the cluster. One of these sequences is situated with its 3' end next to the 3' end of a class I sequence. The other sequence, which does not contain the entire viral envelope, is proximal to the 3' end of a different class I sequence. Hybridization of the viral probes with the H-2 cosmid clones does not appear to be due to homology between viral and H-2 sequences. Rather, the viral sequences detected appear to be linked to or inserted amid class I genes. These findings may be significant in understanding molecular mechanisms involved in the generation of H-2 class I gene diversity.
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Pampeno C, Krakow JS. Cross-linking of the cAMP receptor protein of Escherichia coli by o-phenylenedimaleimide as a probe of conformation. Biochemistry 1979; 18:1519-25. [PMID: 218622 DOI: 10.1021/bi00575a020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Reaction of the cAMP (cyclic adenosine 3'--5'-monophosphate) receptor protein (CRP) of Escherichia coli with the bifunctional reagent o-phenylenedimaleimide (oPDM) results in the cross-linking of the two subunits of a CRP protomer. In the presence of cAMP the rate of cross-linking increases. CRP modified with oPDM retains [3H]cAMP binding activity but loses [3H]d(I-C)n binding activity. Proteolysis of cross-linked CRP gives distinct sodium dodecyl sulfate-polyacrylamide gel electrophoretic patterns depending upon whether cAMP was present during the reaction with oPDM. CRP cross-linked in the absence of cAMP retains the same relative resistance to proteolysis as unmodified CRP. The presence of 0.1 mM cAMP during proteolysis results in the production of two fragments, one of approximately 13 000 daltons and a second of approximately 20 000 daltons. CRP cross-linked with oPDM in the presence of cAMP (then dialyzed to remove cAMP) remains sensitive to alpha-chymotrypsin digestion even in the absence of added cAMP producing only the 13 000-dalton fragment. It is suggested that the nature of the oPDM cross-link is a consequence of the conformational state of CRP.
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Eilen E, Pampeno C, Krakow JS. Production and properties of the alpha core derived from the cyclic adenosine monophosphate receptor protein of Escherichia coli. Biochemistry 1978; 17:2469-73. [PMID: 209817 DOI: 10.1021/bi00606a001] [Citation(s) in RCA: 109] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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