1
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Girard B, Baum-Jones E, Best RL, Campbell TW, Coupart J, Dangerfield K, Dhal A, Jhatro M, Martinez B, Reifert J, Shon J, Zhang M, Waitz R, Chalkias S, Edwards DK, Maglinao M, Paris R, Pajon R. Profiling antibody epitopes induced by mRNA-1273 vaccination and boosters. Front Immunol 2024; 15:1285278. [PMID: 38562934 PMCID: PMC10983613 DOI: 10.3389/fimmu.2024.1285278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 02/27/2024] [Indexed: 04/04/2024] Open
Abstract
Background Characterizing the antibody epitope profiles of messenger RNA (mRNA)-based vaccines against SARS-CoV-2 can aid in elucidating the mechanisms underlying the antibody-mediated immune responses elicited by these vaccines. Methods This study investigated the distinct antibody epitopes toward the SARS-CoV-2 spike (S) protein targeted after a two-dose primary series of mRNA-1273 followed by a booster dose of mRNA-1273 or a variant-updated vaccine among serum samples from clinical trial adult participants. Results Multiple S-specific epitopes were targeted after primary vaccination; while signal decreased over time, a booster dose after >6 months largely revived waning antibody signals. Epitope identity also changed after booster vaccination in some subjects, with four new S-specific epitopes detected with stronger signals after boosting than with primary vaccination. Notably, the strength of antibody responses after booster vaccination differed by the exact vaccine formulation, with variant-updated mRNA-1273.211 and mRNA-1273.617.2 booster formulations inducing significantly stronger S-specific signals than a mRNA-1273 booster. Conclusion Overall, these results identify key S-specific epitopes targeted by antibodies induced by mRNA-1273 primary and variant-updated booster vaccination.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - John Shon
- Serimmune, Goleta, CA, United States
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2
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Haynes WA, Kamath K, Bozekowski J, Baum-Jones E, Campbell M, Casanovas-Massana A, Daugherty PS, Dela Cruz CS, Dhal A, Farhadian SF, Fitzgibbons L, Fournier J, Jhatro M, Jordan G, Klein J, Lucas C, Kessler D, Luchsinger LL, Martinez B, Catherine Muenker M, Pischel L, Reifert J, Sawyer JR, Waitz R, Wunder EA, Zhang M, Iwasaki A, Ko A, Shon JC. High-resolution epitope mapping and characterization of SARS-CoV-2 antibodies in large cohorts of subjects with COVID-19. Commun Biol 2021; 4:1317. [PMID: 34811480 PMCID: PMC8608966 DOI: 10.1038/s42003-021-02835-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/22/2021] [Indexed: 12/12/2022] Open
Abstract
As Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) continues to spread, characterization of its antibody epitopes, emerging strains, related coronaviruses, and even the human proteome in naturally infected patients can guide the development of effective vaccines and therapies. Since traditional epitope identification tools are dependent upon pre-defined peptide sequences, they are not readily adaptable to diverse viral proteomes. The Serum Epitope Repertoire Analysis (SERA) platform leverages a high diversity random bacterial display library to identify proteome-independent epitope binding specificities which are then analyzed in the context of organisms of interest. When evaluating immune response in the context of SARS-CoV-2, we identify dominant epitope regions and motifs which demonstrate potential to classify mild from severe disease and relate to neutralization activity. We highlight SARS-CoV-2 epitopes that are cross-reactive with other coronaviruses and demonstrate decreased epitope signal for mutant SARS-CoV-2 strains. Collectively, the evolution of SARS-CoV-2 mutants towards reduced antibody response highlight the importance of data-driven development of the vaccines and therapies to treat COVID-19. Using a high throughput, random bacterial peptide display approach applied to patient serum samples, Haynes, Kamath, Bozekowski et al identify the antigens and epitopes that elicit a SARS-CoV-2 humoral response. They identify differences depending on disease severity and further in silico analysis suggests decreased epitope signal for Q677P but not for D614G mutant SARSCoV-2 strains.
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Affiliation(s)
| | | | | | | | - Melissa Campbell
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Arnau Casanovas-Massana
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | | | - Charles S Dela Cruz
- Department of Medicine, Section of Pulmonary and Critical Care Medicine, Yale University School of Medicine, New Haven, CT, USA
| | | | - Shelli F Farhadian
- Department of Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT, USA
| | | | - John Fournier
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | | | | | - Jon Klein
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Carolina Lucas
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | | | | | | | - M Catherine Muenker
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Lauren Pischel
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.,Department of Medicine, Section of Infectious Diseases, Yale University School of Medicine, New Haven, CT, USA
| | | | | | | | - Elsio A Wunder
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | | | | | - Akiko Iwasaki
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Albert Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
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3
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Wang K, Dropulic L, Bozekowski J, Pietz HL, Jegaskanda S, Dowdell K, Vogel JS, Garabedian D, Oestreich M, Nguyen H, Ali MA, Lumbard K, Hunsberger S, Reifert J, Haynes WA, Sawyer JR, Shon JC, Daugherty PS, Cohen JI. Serum and Cervicovaginal Fluid Antibody Profiling in Herpes Simplex Virus (HSV) Seronegative Recipients of the HSV529 Vaccine. J Infect Dis 2021; 224:1509-1519. [PMID: 33718970 DOI: 10.1093/infdis/jiab139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 03/12/2021] [Indexed: 11/14/2022] Open
Abstract
Previous HSV2 vaccines have not prevented genital herpes. Concerns have been raised about the choice of antigen, the type of antibody induced by the vaccine, and whether antibody is present in the genital tract where infection occurs. We reported results of a trial of an HSV2 replication-defective vaccine, HSV529, that induced serum neutralizing antibody responses in 78% of HSV1 -/HSV2 - vaccine recipients. Here we show that HSV1 -/HSV2 - vaccine recipients developed antibodies to epitopes of several viral proteins; however, fewer antibody epitopes were detected in vaccine recipients compared with naturally infected persons. HSV529 induced antibodies that mediated HSV2-specific NK cell activation. Depletion of gD-binding antibody from sera reduced neutralizing titers by 62% and NK cell activation by 81%. HSV2 gD antibody was detected in cervicovaginal fluid at about one-third the level of that in serum. A vaccine that induces potent serum antibodies transported to the genital tract might reduce HSV genital infection.
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Affiliation(s)
- Kening Wang
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Lesia Dropulic
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | - Harlan L Pietz
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sinthujan Jegaskanda
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kennichi Dowdell
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Joshua S Vogel
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Doreen Garabedian
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Makinna Oestreich
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Hanh Nguyen
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Mir A Ali
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Keith Lumbard
- Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Sally Hunsberger
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | | | | - Jeffrey I Cohen
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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4
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Reifert J, Kamath K, Bozekowski J, Lis E, Horn EJ, Granger D, Theel ES, Shon J, Sawyer JR, Daugherty PS. Serum Epitope Repertoire Analysis Enables Early Detection of Lyme Disease with Improved Sensitivity in an Expandable Multiplex Format. J Clin Microbiol 2021; 59:e01836-20. [PMID: 33148704 PMCID: PMC8111119 DOI: 10.1128/jcm.01836-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/27/2020] [Indexed: 12/25/2022] Open
Abstract
Widely employed diagnostic antibody serology for Lyme disease, known as standard two-tier testing (STTT), exhibits insufficient sensitivity in early Lyme disease, yielding many thousands of false-negative test results each year. Given this problem, we applied serum antibody repertoire analysis (SERA), or next-generation sequencing (NGS)-based serology, to discover IgG and IgM antibody epitope motifs capable of detecting Lyme disease-specific antibodies with high sensitivity and specificity. Iterative motif discovery and bioinformatic analysis of epitope repertoires from subjects with Lyme disease (n = 264) and controls (n = 391) yielded a set of 28 epitope motifs representing 20 distinct IgG antibody epitopes and a set of 38 epitope motifs representing 21 distinct IgM epitopes, which performed equivalently in a large validation cohort of STTT-positive samples. In a second validation set from subjects with clinically defined early Lyme disease (n = 119) and controls (n = 257), the SERA Lyme IgG and IgM assay exhibited significantly improved sensitivity relative to STTT (77% versus 62%; Z-test; P = 0.013) and improved specificity (99% versus 97%). Early Lyme disease subjects exhibited significantly fewer reactive epitopes (Mann-Whitney U test; P < 0.0001) relative to subjects with Lyme arthritis. Thus, SERA Lyme IgG and M panels provided increased accuracy in early Lyme disease in a readily expandable multiplex assay format.
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Affiliation(s)
| | | | | | - Ewa Lis
- Serimmune Inc., Goleta, California, USA
| | | | - Dane Granger
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester Minnesota, USA
| | - Elitza S Theel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester Minnesota, USA
| | - John Shon
- Serimmune Inc., Goleta, California, USA
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5
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Kamath K, Reifert J, Johnston T, Gable C, Pantazes RJ, Rivera HN, McAuliffe I, Handali S, Daugherty PS. Antibody epitope repertoire analysis enables rapid antigen discovery and multiplex serology. Sci Rep 2020; 10:5294. [PMID: 32210339 PMCID: PMC7093460 DOI: 10.1038/s41598-020-62256-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 03/11/2020] [Indexed: 01/26/2023] Open
Abstract
The detection of pathogen-specific antibodies remains a cornerstone of clinical diagnostics. Yet, many test exhibit undesirable performance or are completely lacking. Given this, we developed serum epitope repertoire analysis (SERA), a method to rapidly discover conserved, pathogen-specific antigens and their epitopes, and applied it to develop an assay for Chagas disease caused by the protozoan parasite Trypanosoma cruzi. Antibody binding peptide motifs were identified from 28 Chagas repertoires using a bacterial display random 12-mer peptide library and next-generation sequencing (NGS). Thirty-three motifs were selected and mapped to candidate Chagas antigens. In a blinded validation set (n = 72), 30/30 Chagas were positive, 30/30 non-Chagas were negative, and 1/12 Leishmania sp. was positive. After unblinding, a Leishmania cross-reactive epitope was identified and removed from the panel. The Chagas assay exhibited 100% sensitivity (30/30) and specificity (90/90) in a second blinded validation set including individuals with other parasitic infections. Amongst additional epitope repertoires with unknown Chagas serostatus, assay specificity was 99.8% (998/1000). Thus, the Chagas assay achieved a combined sensitivity and specificity equivalent or superior to diagnostic algorithms that rely on three separate tests to achieve high specificity. NGS-based serology via SERA provides an effective approach to discover antigenic epitopes and develop high performance multiplex serological assays.
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Affiliation(s)
- Kathy Kamath
- Serimmune Inc., 150 Castilian Dr., Goleta, CA, 93117, USA
| | - Jack Reifert
- Serimmune Inc., 150 Castilian Dr., Goleta, CA, 93117, USA
| | | | - Cameron Gable
- Serimmune Inc., 150 Castilian Dr., Goleta, CA, 93117, USA
| | - Robert J Pantazes
- Serimmune Inc., 150 Castilian Dr., Goleta, CA, 93117, USA
- Department of Chemical Engineering, Auburn University, Auburn, AL, 36849-5127, USA
| | - Hilda N Rivera
- Centers for Disease Control (CDC)- Division of Parasitic Disease and Malaria, 1600 Clifton Road, MS D-64, Atlanta, GA, 30329-4027, USA
| | - Isabel McAuliffe
- Centers for Disease Control (CDC)- Division of Parasitic Disease and Malaria, 1600 Clifton Road, MS D-64, Atlanta, GA, 30329-4027, USA
| | - Sukwan Handali
- Centers for Disease Control (CDC)- Division of Parasitic Disease and Malaria, 1600 Clifton Road, MS D-64, Atlanta, GA, 30329-4027, USA
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6
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Pantazes RJ, Reifert J, Bozekowski J, Ibsen KN, Murray JA, Daugherty PS. Identification of disease-specific motifs in the antibody specificity repertoire via next-generation sequencing. Sci Rep 2016; 6:30312. [PMID: 27481573 PMCID: PMC4969583 DOI: 10.1038/srep30312] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 07/04/2016] [Indexed: 12/12/2022] Open
Abstract
Disease-specific antibodies can serve as highly effective biomarkers but have been identified for only a relatively small number of autoimmune diseases. A method was developed to identify disease-specific binding motifs through integration of bacterial display peptide library screening, next-generation sequencing (NGS) and computational analysis. Antibody specificity repertoires were determined by identifying bound peptide library members for each specimen using cell sorting and performing NGS. A computational algorithm, termed Identifying Motifs Using Next- generation sequencing Experiments (IMUNE), was developed and applied to discover disease- and healthy control-specific motifs. IMUNE performs comprehensive pattern searches, identifies patterns statistically enriched in the disease or control groups and clusters the patterns to generate motifs. Using celiac disease sera as a discovery set, IMUNE identified a consensus motif (QPEQPF[PS]E) with high diagnostic sensitivity and specificity in a validation sera set, in addition to novel motifs. Peptide display and sequencing (Display-Seq) coupled with IMUNE analysis may thus be useful to characterize antibody repertoires and identify disease-specific antibody epitopes and biomarkers.
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Affiliation(s)
- Robert J Pantazes
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.,Serimmune, Inc, Santa Barbara, CA 93105, USA
| | - Jack Reifert
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.,Serimmune, Inc, Santa Barbara, CA 93105, USA
| | - Joel Bozekowski
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Kelly N Ibsen
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Joseph A Murray
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905, USA
| | - Patrick S Daugherty
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.,Serimmune, Inc, Santa Barbara, CA 93105, USA
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7
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Benbow SJ, Cook BM, Reifert J, Wozniak KM, Slusher BS, Littlefield BA, Wilson L, Jordan MA, Feinstein SC. Effects of Paclitaxel and Eribulin in Mouse Sciatic Nerve: A Microtubule-Based Rationale for the Differential Induction of Chemotherapy-Induced Peripheral Neuropathy. Neurotox Res 2015; 29:299-313. [DOI: 10.1007/s12640-015-9580-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 12/15/2022]
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8
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Shropshire TD, Reifert J, Rajagopalan S, Baker D, Feinstein SC, Daugherty PS. Amyloid β peptide cleavage by kallikrein 7 attenuates fibril growth and rescues neurons from Aβ-mediated toxicity in vitro. Biol Chem 2014; 395:109-18. [PMID: 23989112 DOI: 10.1515/hsz-2013-0230] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 08/27/2013] [Indexed: 12/23/2022]
Abstract
The gradual accumulation and assembly of β-amyloid (Aβ) peptide into neuritic plaques is a major pathological hallmark of Alzheimer disease (AD). Proteolytic degradation of Aβ is an important clearance mechanism under normal circumstances, and it has been found to be compromised in those with AD. Here, the extended substrate specificity and Aβ-degrading capacity of kallikrein 7 (KLK7), a serine protease with a unique chymotrypsin-like specificity, was characterized. Preferred peptide substrates of KLK7 identified using a bacterial display substrate library were found to exhibit a consensus motif of RXΦ(Y/F)↓(Y/F)↓(S/A/G/T) or RXΦ(Y/F)↓(S/T/A) (Φ=hydrophobic), which is remarkably similar to the hydrophobic core motif of Aβ (K16L17V18F19F20 A21) that is largely responsible for aggregation propensity. KLK7 was found to cleave after both Phe residues within the core of Aβ42 in vitro, thereby inhibiting Aβ fibril formation and promoting the degradation of preformed fibrils. Finally, the treatment of Aβ oligomer preparations with KLK7, but not inactive pro-KLK7, significantly reduced Aβ42-mediated toxicity to rat hippocampal neurons to the same extent as the known Aβ-degrading protease insulin-degrading enzyme (IDE). Taken together, these results indicate that KLK7 possesses an Aβ-degrading capacity that can ameliorate the toxic effects of the aggregated peptide in vitro.
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9
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Reifert J, Hartung-Cranston D, Feinstein SC. Amyloid beta-mediated cell death of cultured hippocampal neurons reveals extensive Tau fragmentation without increased full-length tau phosphorylation. J Biol Chem 2011; 286:20797-811. [PMID: 21482827 DOI: 10.1074/jbc.m111.234674] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A variety of genetic and biochemical evidence suggests that amyloid β (Aβ) oligomers promote downstream errors in Tau action, in turn inducing neuronal dysfunction and cell death in Alzheimer and related dementias. To better understand molecular mechanisms involved in Aβ-mediated neuronal cell death, we have treated primary rat hippocampal cultures with Aβ oligomers and examined the resulting cellular changes occurring before and during the induction of cell death with a focus on altered Tau biochemistry. The most rapid neuronal responses upon Aβ administration are activation of caspase 3/7 and calpain proteases. Aβ also appears to reduce Akt and Erk1/2 kinase activities while increasing GSK3β and Cdk5 activities. Shortly thereafter, substantial Tau degradation begins, generating relatively stable Tau fragments. Only a very small fraction of full-length Tau remains intact after 4 h of Aβ treatment. In conflict with expectations based on suggested increases of GSK3β and Cdk5 activities, Aβ does not cause any major increases in phosphorylation of full-length Tau as assayed by immunoblotting one-dimensional gels with 11 independent site- and phospho-specific anti-Tau antibodies as well as by immunoblotting two-dimensional gels probed with a pan-Tau antibody. There are, however, subtle and transient increases in Tau phosphorylation at 3-4 specific sites before its degradation. Taken together, these data are consistent with the notion that Aβ-mediated neuronal cell death involves the loss of full-length Tau and/or the generation of toxic fragments but does not involve or require hyperphosphorylation of full-length Tau.
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Affiliation(s)
- Jack Reifert
- Neuroscience Research Institute and Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, USA
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10
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Leoni LM, Bailey B, Reifert J, Bendall HH, Zeller RW, Corbeil J, Elliott G, Niemeyer CC. Bendamustine (Treanda) displays a distinct pattern of cytotoxicity and unique mechanistic features compared with other alkylating agents. Clin Cancer Res 2008; 14:309-17. [PMID: 18172283 DOI: 10.1158/1078-0432.ccr-07-1061] [Citation(s) in RCA: 270] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Bendamustine has shown clinical activity in patients with disease refractory to conventional alkylator chemotherapy. The purpose of this study was to characterize the mechanisms of action of bendamustine and to compare it with structurally related compounds. EXPERIMENTAL DESIGN Bendamustine was profiled in the National Cancer Institute in vitro antitumor screen. Microarray-based gene expression profiling, real-time PCR, immunoblot, cell cycle, and functional DNA damage repair analyses were used to characterize response to bendamustine and compare it with chlorambucil and phosphoramide mustard. RESULTS Bendamustine displays a distinct pattern of activity unrelated to other DNA-alkylating agents. Its mechanisms of action include activation of DNA-damage stress response and apoptosis, inhibition of mitotic checkpoints, and induction of mitotic catastrophe. In addition, unlike other alkylators, bendamustine activates a base excision DNA repair pathway rather than an alkyltransferase DNA repair mechanism. CONCLUSION These results suggest that bendamustine possesses mechanistic features that differentiate it from other alkylating agents and may contribute to its distinct clinical efficacy profile.
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Affiliation(s)
- Lorenzo M Leoni
- Salmedix, acquired by Cephalon, Inc., Frazer, Pennsylvania, USA
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11
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Kanekal S, Crain B, Elliott G, Chao Q, Reifert J, Bailey B, Bendall H, Niemeyer C, Leoni L. 383 Preclinical antitumor activity of second generation analogs of SDX-101. EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)80390-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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12
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Sen M, Reifert J, Lauterbach K, Wolf V, Rubin JS, Corr M, Carson DA. Regulation of fibronectin and metalloproteinase expression by Wnt signaling in rheumatoid arthritis synoviocytes. Arthritis Rheum 2002; 46:2867-77. [PMID: 12428226 DOI: 10.1002/art.10593] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The enhanced release of extracellular matrix proteins by fibroblast-like synoviocytes (FLS) from rheumatoid arthritis (RA) patients is suggestive of joint remodeling. Because Wnt proteins play a critical role in joint development, we investigated whether up-regulated Wnt signaling plays a role in the enhanced synthesis of extracellular matrix proteins. The purpose of the present experiments was to determine the role of Wnt-1-like molecules in the expression of matrix proteins by RA FLS and to ascertain the effects of Wnt antagonists on RA FLS function and survival. METHODS Transfection with a reporter plasmid (TOPflash) was performed to assess whether Wnt signaling is active in RA FLS. Wnt signaling was up-regulated in normal FLS by transfection with a Wnt-1 expression plasmid and was down-regulated in RA FLS by transfection with dominant-negative lymphoid enhancer factor 1 (LEF-1)/T cell factor 4 (TCF-4) and secreted Frizzled receptor protein 1 (sFRP-1) expression plasmids. Recombinant sFRP-1 and anti-Wnt-1 antibody were also administered to RA FLS to block Wnt signaling. RESULTS RA FLS had constitutive activation of the canonical Wnt signaling pathway. Transfection of normal FLS with a Wnt-1 expression vector enhanced not only fibronectin, but also pro-matrix metalloproteinase 3 (proMMP-3) expression. In a complementary manner, interference with Wnt signaling using anti-Wnt-1 antibody, the Wnt antagonist sFRP-1, or dominant-negative vectors that inhibited the transcription factors TCF-4/LEF-1 blocked the expression of fibronectin by RA FLS and reduced cell survival. Anti-Wnt-1 antibody and sFRP-1 also blocked the expression of proMMP-3. CONCLUSION Our results indicate that the canonical Wnt pathway regulates fibronectin and metalloproteinase expression in RA FLS.
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Affiliation(s)
- Malini Sen
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0663, USA.
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13
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Abstract
OBJECTIVE It is not understood why cultured fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis (RA) often display a persistently activated phenotype, despite removal from an inflammatory environment. Previously, we found that these FLS expressed high levels of both Wnt-5A and Frizzled 5 (Fz5), a receptor-ligand pair implicated in both limb bud and bone marrow stem cell development. The objective of the present experiments was to determine whether Wnt-5A/FzS signaling contributes to FLS activation. METHODS Wnt-5A expression in FLS was inhibited by transfection with both antisense and dominant negative (dn) vectors. Fz5 signaling was blocked with an antibody to the extracellular domain of the receptor. The effects of these treatments on the expression of the proinflammatory cytokines interleukin-6 (IL-6) and IL-15 and on the expression of receptor activator of nuclear factor kappaB ligand (RANKL) were assessed by reverse transcriptase-polymerase chain reaction and immunoblotting. RESULTS Both antisense Wnt-5A and dnWnt-5A vectors, but not empty vector, diminished IL-6 and IL-15 expression in RA FLS. Anti-Fz5 antibody exerted similar effects and also reduced RANKL expression. CONCLUSION Wnt-5A/Fz5 signaling may contribute to the activated state of FLS in RA. Receptor antagonists of Fz5 should be considered for the treatment of refractory synovitis.
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Affiliation(s)
- M Sen
- Department of Medicine, University of California, San Diego, La Jolla 92093-0663, USA
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