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Rosati M, Terpos E, Homan P, Bergamaschi C, Karaliota S, Ntanasis-Stathopoulos I, Devasundaram S, Bear J, Burns R, Bagratuni T, Trougakos IP, Dimopoulos MA, Pavlakis GN, Felber BK. Rapid transient and longer-lasting innate cytokine changes associated with adaptive immunity after repeated SARS-CoV-2 BNT162b2 mRNA vaccinations. Front Immunol 2023; 14:1292568. [PMID: 38090597 PMCID: PMC10711274 DOI: 10.3389/fimmu.2023.1292568] [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: 09/11/2023] [Accepted: 11/14/2023] [Indexed: 12/18/2023] Open
Abstract
Introduction Cytokines and chemokines play an important role in shaping innate and adaptive immunity in response to infection and vaccination. Systems serology identified immunological parameters predictive of beneficial response to the BNT162b2 mRNA vaccine in COVID-19 infection-naïve volunteers, COVID-19 convalescent patients and transplant patients with hematological malignancies. Here, we examined the dynamics of the serum cytokine/chemokine responses after the 3rd BNT162b2 mRNA vaccination in a cohort of COVID-19 infection-naïve volunteers. Methods We measured serum cytokine and chemokine responses after the 3rd dose of the BNT162b2 mRNA (Pfizer/BioNtech) vaccine in COVID-19 infection-naïve individuals by a chemiluminescent assay and ELISA. Anti-Spike binding antibodies were measured by ELISA. Anti-Spike neutralizing antibodies were measured by a pseudotype assay. Results Comparison to responses found after the 1st and 2nd vaccinations showed persistence of the coordinated responses of several cytokine/chemokines including the previously identified rapid and transient IL-15, IFN-γ, CXCL10/IP-10, TNF-α, IL-6 signature. In contrast to the transient (24hrs) effect of the IL-15 signature, an inflammatory/anti-inflammatory cytokine signature (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CXCL8/IL-8, IL-1Ra) remained at higher levels up to one month after the 2nd and 3rd booster vaccinations, indicative of a state of longer-lasting innate immune change. We also identified a systemic transient increase of CXCL13 only after the 3rd vaccination, supporting stronger germinal center activity and the higher anti-Spike antibody responses. Changes of the IL-15 signature, and the inflammatory/anti-inflammatory cytokine profile correlated with neutralizing antibody levels also after the 3rd vaccination supporting their role as immune biomarkers for effective development of vaccine-induced humoral responses. Conclusion These data revealed that repeated SARS-Cov-2 BNT162b2 mRNA vaccination induces both rapid transient as well as longer-lasting systemic serum cytokine changes associated with innate and adaptive immune responses. Clinical trial registration Clinicaltrials.gov, identifier NCT04743388.
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Affiliation(s)
- Margherita Rosati
- Human Retrovirus Pathogenesis Section, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
| | - Evangelos Terpos
- Department of Clinical Therapeutics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Philip Homan
- Center for Cancer Research Collaborative Bioinformatics Resource, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, United States
| | - Cristina Bergamaschi
- Human Retrovirus Pathogenesis Section, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
| | - Sevasti Karaliota
- Human Retrovirus Pathogenesis Section, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
- Basic Science Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, United States
| | - Ioannis Ntanasis-Stathopoulos
- Department of Clinical Therapeutics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Santhi Devasundaram
- Human Retrovirus Pathogenesis Section, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
| | - Jenifer Bear
- Human Retrovirus Pathogenesis Section, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
| | - Robert Burns
- Human Retrovirus Pathogenesis Section, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
| | - Tina Bagratuni
- Department of Clinical Therapeutics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Ioannis P. Trougakos
- Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Meletios A. Dimopoulos
- Department of Clinical Therapeutics, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - George N. Pavlakis
- Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
| | - Barbara K. Felber
- Human Retrovirus Pathogenesis Section, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, United States
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Monge C, Xie C, Myojin Y, Coffman K, Hrones DM, Wang S, Hernandez JM, Wood BJ, Levy EB, Juburi I, Hewitt SM, Kleiner DE, Steinberg SM, Figg WD, Redd B, Homan P, Cam M, Ruf B, Duffy AG, Greten TF. Phase I/II study of PexaVec in combination with immune checkpoint inhibition in refractory metastatic colorectal cancer. J Immunother Cancer 2023; 11:jitc-2022-005640. [PMID: 36754451 PMCID: PMC9923269 DOI: 10.1136/jitc-2022-005640] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [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] [Accepted: 12/30/2022] [Indexed: 02/10/2023] Open
Abstract
BACKGROUND Oncolytic immunotherapy represents a unique therapeutic platform for the treatment of cancer. Here, we evaluated the safety and efficacy of the combination of pexastimogene devacirepvec (PexaVec) plus durvalumab (anti-programmed death ligand 1) with and without tremelimumab (anti-cytotoxic T-lymphocyte associated protein 4) in patients with standard chemotherapy refractory mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC) in a phase I/II trial. METHODS Adult patients with histologically confirmed advanced pMMR mCRC, who had progressed on at least two prior lines of systemic chemotherapy were studied in four cohorts. Patients received four doses of PexaVec IV at a dose of 3×108 plaque forming units (pfu) (dose level 1) or 1×109 pfu (dose level 2) every 2 weeks. Twelve days after the first PexaVec administration, patients received either 1500 mg of durvalumab every 28 days alone or an additional single dose of 300 mg tremelimumab on day 1. Responses were assessed every 8 weeks by CT or MRI. AEs were recorded. The primary endpoints were safety and feasibility. Secondary endpoints included progression-free survival (PFS) and overall survival. Paired tumor samples and peripheral blood were collected to perform immune monitoring. RESULTS Thirty-four patients with mCRC enrolled on to the study: 16 patients in the PexaVec/durvalumab cohorts and 18 patients in the PexaVec/durvalumab/tremelimumab cohorts. Overall, the combination of PexaVec plus immune checkpoint inhibitors did not result in any unexpected toxicities. Most common toxicities observed were fever and chills after PexaVec infusion. Two cases of grade 3 colitis, one case of a grade 2 myositis and one case of grade 3 hypotension resulted in discontinuation of immune checkpoint inhibitor and PexaVec treatment, respectively. The median PFS in the PexaVec/durvalumab/tremelimumab cohorts was 2.3 months (95% CI: 2.2 to 3.2 months) vs 2.1 months (95% CI: 1.7 to 2.8 months; p=0.57) in the PexaVec/durvalumab cohorts. Flow cytometry analysis of peripheral blood mononuclear cells revealed an increase in Ki67+CD8+ T cells on treatment. CONCLUSION PexaVec in combination with durvalumab and tremelimumab is safe and tolerable. No unexpected toxicities were observed. The combination of PexaVec/durvalumab/tremelimumab demonstrated potential clinical activity in patients with pMMR mCRC, but further studies are needed to identify the predictive biomarkers. TRIAL REGISTRATION NUMBER NCT03206073.
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Affiliation(s)
- Cecilia Monge
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Changqing Xie
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Yuta Myojin
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Kelley Coffman
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Donna Mabry Hrones
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Sophie Wang
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jonathan M Hernandez
- Surgical Oncology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Bradford J Wood
- Center for Interventional Oncology, Radiology and Imaging Sciences, NIH Clinical Center & Center for Cancer Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Elliot B Levy
- Center for Interventional Oncology, Radiology and Imaging Sciences, NIH Clinical Center & Center for Cancer Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Israa Juburi
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Stephen M Hewitt
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - David E Kleiner
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Seth M Steinberg
- Biostatistics and Data Management Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - William D Figg
- Molecular Pharmacology Section, Genitourinary Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Bernadette Redd
- Radiology and Imaging Sciences, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Philip Homan
- Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Maggie Cam
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Benjamin Ruf
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Austin G Duffy
- Mater Misericordiae University Hospital, Dublin, Ireland
| | - Tim F Greten
- Gastrointestinal Malignancies Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
- Liver Cancer Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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Dominguez MP, Homan P, Zhang X, Reyes SN, Guerin T, Bassel L, Liu ZR, Kozlov S, Alewine C. Abstract C058: Remodeling the tumor microenvironment by targeting integrin alpha V beta 3 (αvβ3) expressing cells in pancreatic cancer. Cancer Res 2022. [DOI: 10.1158/1538-7445.panca22-c058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Abstract
ProAgio is a therapeutic cytotoxin that targets and kills integrin αvβ3-expressing cells, resulting in reduced tumor collagen, decreased formation of new blood vessels in the tumor microenvironment (TME), and prolonged survival in mouse models of pancreatic ductal adenocarcinoma (PDAC). ProAgio is currently being tested in a Phase 1 dose-finding study in patients with solid tumors including pancreas cancers. The cell subsets within the PDAC TME that express integrin αvβ3 and could be subject to ProAgio-mediated killing have not been previously studied. Using the KPC genetically engineered mouse model of PDAC, we found that ProAgio (20 mg/kg daily, x7 days) restrained tumor growth by 20% compared to vehicle treatment without changing the cancer cell proliferation rate. We subsequently re-analyzed publicly available scRNA-seq PDAC datasets to identify cells present in human and mouse PDAC tumors that co-express integrins αv and β3 and could be targets of ProAgio. We found that specific subsets of cancer-associated fibroblasts (CAFs), monocytes and macrophages expressed both integrins. Flow cytometry was performed on cells dissociated from orthotopically implanted KPC-derived tumors treated for 15 days with ProAgio or vehicle to identify TME subsets affected by ProAgio treatment. There was no significant difference in the myofibroblast (myCAF) subset, but an increase in the percentage of inflammatory CAFs (iCAFs) was seen. ProAgio treatment also significantly increased the percentage of conventional dendritic cells which play a pivotal role in antigen recognition and T cell priming. T cell abundance was unchanged, but a decrease in B cells was observed. These data demonstrate that ProAgio treatment modifies specific immune and fibroblast subsets within the PDAC TME. Ongoing studies seek to further delineate the cell subtypes affected by ProAgio and the cytokine and chemokine mediators responsible for these changes.
Citation Format: Mayrel Palestino Dominguez, Philip Homan, Xianyu Zhang, Sandra Navas Reyes, Theresa Guerin, Laura Bassel, Zhi-ren Liu, Serguei Kozlov, Christine Alewine. Remodeling the tumor microenvironment by targeting integrin alpha V beta 3 (αvβ3) expressing cells in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C058.
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Affiliation(s)
| | - Philip Homan
- 1Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD,
| | - Xianyu Zhang
- 1Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD,
| | - Sandra Navas Reyes
- 2Center for Advanced Preclinical Research, Frederick National Laboratory for Cancer Research, Frederick, MD,
| | - Theresa Guerin
- 2Center for Advanced Preclinical Research, Frederick National Laboratory for Cancer Research, Frederick, MD,
| | - Laura Bassel
- 2Center for Advanced Preclinical Research, Frederick National Laboratory for Cancer Research, Frederick, MD,
| | | | - Serguei Kozlov
- 2Center for Advanced Preclinical Research, Frederick National Laboratory for Cancer Research, Frederick, MD,
| | - Christine Alewine
- 1Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD,
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Affiliation(s)
- P Homan
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Manhasset, NY, USA.,Division of Psychiatry Research, The Zucker Hillside Hospital, Northwell Health, New York, NY, USA.,Department of Psychiatry, The Donald and Barbara Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA
| | - J M Kane
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Manhasset, NY, USA.,Division of Psychiatry Research, The Zucker Hillside Hospital, Northwell Health, New York, NY, USA.,Department of Psychiatry, The Donald and Barbara Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA
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Huang QQ, Birkett R, Doyle RE, Haines GK, Perlman H, Shi B, Homan P, Xing L, Pope RM. Association of Increased F4/80 high Macrophages With Suppression of Serum-Transfer Arthritis in Mice With Reduced FLIP in Myeloid Cells. Arthritis Rheumatol 2017; 69:1762-1771. [PMID: 28511285 DOI: 10.1002/art.40151] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 05/09/2017] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Macrophages are critical in the pathogenesis of rheumatoid arthritis (RA). We recently demonstrated that FLIP is necessary for the differentiation and/or survival of macrophages. We also showed that FLIP is highly expressed in RA synovial macrophages. This study was undertaken to determine if a reduction in FLIP in mouse macrophages reduces synovial tissue macrophages and ameliorates serum-transfer arthritis. METHODS Mice with Flip deleted in myeloid cells (Flipf/f LysMc/+ mice) and littermate controls were used. Arthritis was induced by intraperitoneal injection of K/BxN serum. Disease severity was evaluated by clinical score and change in ankle thickness, and joints were examined by histology and immunohistochemistry. Cells were isolated from the ankles and bone marrow of the mice and examined by flow cytometry, real-time quantitative reverse transcriptase-polymerase chain reaction, or Western blotting. RESULTS In contrast to expectations, Flipf/f LysMc/+ mice developed more severe arthritis early in the clinical course, but peak arthritis was attenuated and the resolution phase more complete than in control mice. Prior to the induction of serum-transfer arthritis, the number of tissue-resident macrophages was reduced. On day 9 after arthritis induction, the number of F4/80high macrophages in the joints of the Flipf/f LysMc/+ mice was not decreased, but increased. FLIP was reduced in the F4/80high macrophages in the ankles of the Flipf/f LysMc/+ mice, while F4/80high macrophages expressed an antiinflammatory phenotype in both the Flipf/f LysMc/+ and control mice. CONCLUSION Our observations suggest that reducing FLIP in macrophages by increasing the number of antiinflammatory macrophages may be an effective therapeutic approach to suppress inflammation, depending on the disease stage.
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Affiliation(s)
- Qi-Quan Huang
- Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Robert Birkett
- Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Renee E Doyle
- Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | | | - Harris Perlman
- Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Bo Shi
- Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Philip Homan
- Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Lianping Xing
- University of Rochester Medical Center, Rochester, New York
| | - Richard M Pope
- Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Hasler G, Homan P, Neumeister A, Nugent A, Charney D, Drevets W. Differenital Behavioral and Neural Consequences of Serotonin and Catecholamine Deficiency in Depression: an Experimental Study. Eur Psychiatry 2015. [DOI: 10.1016/s0924-9338(15)31019-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Homan P, Neumeister A, Nugent AC, Charney DS, Drevets WC, Hasler G. Serotonin versus catecholamine deficiency: behavioral and neural effects of experimental depletion in remitted depression. Transl Psychiatry 2015; 5:e532. [PMID: 25781231 PMCID: PMC4354355 DOI: 10.1038/tp.2015.25] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/12/2015] [Accepted: 01/20/2015] [Indexed: 12/22/2022] Open
Abstract
Despite immense efforts into development of new antidepressant drugs, the increases of serotoninergic and catecholaminergic neurotransmission have remained the two major pharmacodynamic principles of current drug treatments for depression. Consequently, psychopathological or biological markers that predict response to drugs that selectively increase serotonin and/or catecholamine neurotransmission hold the potential to optimize the prescriber's selection among currently available treatment options. The aim of this study was to elucidate the differential symptomatology and neurophysiology in response to reductions in serotonergic versus catecholaminergic neurotransmission in subjects at high risk of depression recurrence. Using identical neuroimaging procedures with [(18)F] fluorodeoxyglucose positron emission tomography after tryptophan depletion (TD) and catecholamine depletion (CD), subjects with remitted depression were compared with healthy controls in a double-blind, randomized, crossover design. Although TD induced significantly more depressed mood, sadness and hopelessness than CD, CD induced more inactivity, concentration difficulties, lassitude and somatic anxiety than TD. CD specifically increased glucose metabolism in the bilateral ventral striatum and decreased glucose metabolism in the bilateral orbitofrontal cortex, whereas TD specifically increased metabolism in the right prefrontal cortex and the posterior cingulate cortex. Although we found direct associations between changes in brain metabolism and induced depressive symptoms following CD, the relationship between neural activity and symptoms was less clear after TD. In conclusion, this study showed that serotonin and catecholamines have common and differential roles in the pathophysiology of depression.
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Affiliation(s)
- P Homan
- Division of Molecular Psychiatry, Translational Research Center, University Hospital of Psychiatry, University of Bern, Bern, Switzerland
| | - A Neumeister
- Molecular Imaging Program, Department of Psychiatry and Radiology, New York University School of Medicine, New York, NY, USA
| | - A C Nugent
- Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, and Department of Health and Human Services, Bethesda, MD, USA
| | - D S Charney
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - W C Drevets
- Laureate Institute for Brain Research, Tulsa, OK, USA,Janssen Pharmaceuticals Research & Development, Titusville, NJ, USA
| | - G Hasler
- Division of Molecular Psychiatry, Translational Research Center, University Hospital of Psychiatry, University of Bern, Bern, Switzerland,Division of Molecular Psychiatry, Translational Research Center, University Hospital of Psychiatry, University of Bern, Bolligenstrasse 111, Bern 3000, Switzerland. E-mail:
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Warner KD, Homan P, Weeks KM, Smith AG, Abell C, Ferré-D'Amaré AR. Validating fragment-based drug discovery for biological RNAs: lead fragments bind and remodel the TPP riboswitch specifically. ACTA ACUST UNITED AC 2014; 21:591-5. [PMID: 24768306 DOI: 10.1016/j.chembiol.2014.03.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 11/26/2022]
Abstract
Thiamine pyrophosphate (TPP) riboswitches regulate essential genes in bacteria by changing conformation upon binding intracellular TPP. Previous studies using fragment-based approaches identified small molecule "fragments" that bind this gene-regulatory mRNA domain. Crystallographic studies now show that, despite having micromolar Kds, four different fragments bind the TPP riboswitch site-specifically, occupying the pocket that recognizes the aminopyrimidine of TPP. Unexpectedly, the unoccupied site that would recognize the pyrophosphate of TPP rearranges into a structure distinct from that of the cognate complex. This idiosyncratic fragment-induced conformation, also characterized by small-angle X-ray scattering and chemical probing, represents a possible mechanism for adventitious ligand discrimination by the riboswitch, and suggests that off-pathway conformations of RNAs can be targeted for drug development. Our structures, together with previous screening studies, demonstrate the feasibility of fragment-based drug discovery against RNA targets.
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Affiliation(s)
- Katherine Deigan Warner
- National Heart, Lung and Blood Institute, 50 South Drive, MSC 8012, Bethesda, MD 20892-8012, USA; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Philip Homan
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Kevin M Weeks
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Alison G Smith
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Chris Abell
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Adrian R Ferré-D'Amaré
- National Heart, Lung and Blood Institute, 50 South Drive, MSC 8012, Bethesda, MD 20892-8012, USA.
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Atallah T, Blankespoor RL, Homan P, Hulderman C, Samas BM, Van Allsburg K, Vrieze DC. Substituent effects on the amination of racemic allyl carbonates using commercially available chiral rhodium catalysts. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.08.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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