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Aggarwal C, Ahmed H, Sharma P, Reddy ES, Nayak K, Singla M, Maheshwari D, Chawla YM, Panda H, Rai RC, Gunisetty S, Priyamvada L, Bhaumik SK, Ahamed SF, Vivek R, Bhatnagar P, Singh P, Kaur M, Dixit K, Kumar S, Gottimukkala K, Saini K, Bajpai P, Sreekanth GP, Mammen S, Rajan A, Verghese VP, Abraham AM, Shah P, Alagarasu K, Yu T, Davis CW, Wrammert J, Ansari A, Antia R, Kabra SK, Medigeshi GR, Ahmed R, Lodha R, Shet A, Chandele A, Murali-Krishna K. Severe disease during both primary and secondary dengue virus infections in pediatric populations. Nat Med 2024; 30:670-674. [PMID: 38321219 DOI: 10.1038/s41591-024-02798-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/02/2024] [Indexed: 02/08/2024]
Abstract
Dengue is a global epidemic causing over 100 million cases annually. The clinical symptoms range from mild fever to severe hemorrhage and shock, including some fatalities. The current paradigm is that these severe dengue cases occur mostly during secondary infections due to antibody-dependent enhancement after infection with a different dengue virus serotype. India has the highest dengue burden worldwide, but little is known about disease severity and its association with primary and secondary dengue infections. To address this issue, we examined 619 children with febrile dengue-confirmed infection from three hospitals in different regions of India. We classified primary and secondary infections based on IgM:IgG ratios using a dengue-specific enzyme-linked immunosorbent assay according to the World Health Organization guidelines. We found that primary dengue infections accounted for more than half of total clinical cases (344 of 619), severe dengue cases (112 of 202) and fatalities (5 of 7). Consistent with the classification based on binding antibody data, dengue neutralizing antibody titers were also significantly lower in primary infections compared to secondary infections (P ≤ 0.0001). Our findings question the currently widely held belief that severe dengue is associated predominantly with secondary infections and emphasizes the importance of developing vaccines or treatments to protect dengue-naive populations.
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Affiliation(s)
- Charu Aggarwal
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Hasan Ahmed
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Pragati Sharma
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Elluri Seetharami Reddy
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Kaustuv Nayak
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Mohit Singla
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Deepti Maheshwari
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Yadya M Chawla
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Harekrushna Panda
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Ramesh Chandra Rai
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sivaram Gunisetty
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- Department of Pediatrics, Division of Infectious Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Lalita Priyamvada
- Department of Pediatrics, Division of Infectious Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Siddhartha Kumar Bhaumik
- Department of Pediatrics, Division of Infectious Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Syed Fazil Ahamed
- Division of Infectious Diseases, St. John's Research Institute, St. John's National Academy of Health Sciences, Bengaluru, India
| | - Rosario Vivek
- Division of Infectious Diseases, St. John's Research Institute, St. John's National Academy of Health Sciences, Bengaluru, India
- The University of Trans-Disciplinary Health Sciences & Technology, Bengaluru, India
| | - Priya Bhatnagar
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- TERI school of advanced studies, New Delhi, India
| | - Prabhat Singh
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Manpreet Kaur
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Kritika Dixit
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sanjeev Kumar
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Kamal Gottimukkala
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Keshav Saini
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Prashant Bajpai
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Gopinathan Pillai Sreekanth
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Shobha Mammen
- Department of Clinical Virology, Christian Medical College, Vellore, India
| | - Anand Rajan
- Department of Clinical Virology, Christian Medical College, Vellore, India
| | - Valsan Philip Verghese
- Pediatric Infectious Diseases, Department of Pediatrics, Christian Medical College, Vellore, India
| | - Asha Mary Abraham
- Department of Clinical Virology, Christian Medical College, Vellore, India
| | - Paresh Shah
- Department of Molecular Virology, National Institute of Virology, Pune, India
| | - Kalichamy Alagarasu
- Department of Molecular Virology, National Institute of Virology, Pune, India
| | - Tianwei Yu
- Rollins School of Public Health, Emory University, Atlanta, GA, USA
- Shenzhen Research Institute of Big Data, School of Data Science, The Chinese University of Hong Kong, Shenzhen, Guangdong, China
| | - Carl W Davis
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Jens Wrammert
- Department of Pediatrics, Division of Infectious Disease, Emory University School of Medicine, Atlanta, GA, USA
| | - Aftab Ansari
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Rustom Antia
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Sushil Kumar Kabra
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Guruprasad R Medigeshi
- Translational Health Science and Technology Institute, NCR Biotech Science Cluster, Faridabad, India
| | - Rafi Ahmed
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, USA.
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA.
| | - Rakesh Lodha
- Division of Pediatric Pulmonology and Intensive Care, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India.
| | - Anita Shet
- Division of Infectious Diseases, St. John's Research Institute, St. John's National Academy of Health Sciences, Bengaluru, India.
- International Vaccine Access Centre, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Anmol Chandele
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
| | - Kaja Murali-Krishna
- ICGEB Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
- Department of Pediatrics, Division of Infectious Disease, Emory University School of Medicine, Atlanta, GA, USA.
- Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA, USA.
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2
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Singh P, Bajpai P, Maheshwari D, Chawla YM, Saini K, Reddy ES, Gottimukkala K, Nayak K, Gunisetty S, Aggarwal C, Jain S, Verma C, Singla P, Soneja M, Wig N, Murali-Krishna K, Chandele A. Functional and transcriptional heterogeneity within the massively expanding HLADR +CD38 + CD8 T cell population in acute febrile dengue patients. J Virol 2023; 97:e0074623. [PMID: 37855600 PMCID: PMC10688317 DOI: 10.1128/jvi.00746-23] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 09/17/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE CD8 T cells play a crucial role in protecting against intracellular pathogens such as viruses by eliminating infected cells and releasing anti-viral cytokines such as interferon gamma (IFNγ). Consequently, there is significant interest in comprehensively characterizing CD8 T cell responses in acute dengue febrile patients. Previous studies, including our own, have demonstrated that a discrete population of CD8 T cells with HLADR+ CD38+ phenotype undergoes massive expansion during the acute febrile phase of natural dengue virus infection. Although about a third of these massively expanding HLADR+ CD38+ CD8 T cells were also CD69high when examined ex vivo, only a small fraction of them produced IFNγ upon in vitro peptide stimulation. Therefore, to better understand such functional diversity of CD8 T cells responding to dengue virus infection, it is important to know the cytokines/chemokines expressed by these peptide-stimulated HLADR+CD38+ CD8 T cells and the transcriptional profiles that distinguish the CD69+IFNγ+, CD69+IFNγ-, and CD69-IFNγ- subsets.
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Affiliation(s)
- Prabhat Singh
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Prashant Bajpai
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Deepti Maheshwari
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Yadya M. Chawla
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Keshav Saini
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Kamalvishnu Gottimukkala
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Kaustuv Nayak
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Sivaram Gunisetty
- Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Charu Aggarwal
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Shweta Jain
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Chaitanya Verma
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Paras Singla
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Manish Soneja
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Naveet Wig
- Department of Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Kaja Murali-Krishna
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, Georgia, USA
- Emory Vaccine Center, Emory University, Atlanta, Georgia, USA
| | - Anmol Chandele
- ICGEB-Emory Vaccine Center, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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3
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Patel A, Kumar S, Lai L, Chakravarthy C, Valanparambil R, Reddy ES, Gottimukkala K, Bajpai P, Raju DR, Edara VV, Davis-Gardner ME, Linderman S, Dixit K, Sharma P, Mantus G, Cheedarla N, Verkerke HP, Frank F, Neish AS, Roback JD, Davis CW, Wrammert J, Ahmed R, Suthar MS, Sharma A, Murali-Krishna K, Chandele A, Ortlund EA. Molecular basis of SARS-CoV-2 Omicron variant evasion from shared neutralizing antibody response. Structure 2023; 31:801-811.e5. [PMID: 37167972 PMCID: PMC10171968 DOI: 10.1016/j.str.2023.04.010] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/09/2023] [Accepted: 04/21/2023] [Indexed: 05/13/2023]
Abstract
Understanding the molecular features of neutralizing epitopes is important for developing vaccines/therapeutics against emerging SARS-CoV-2 variants. We describe three monoclonal antibodies (mAbs) generated from COVID-19 recovered individuals during the first wave of the pandemic in India. These mAbs had publicly shared near germline gene usage and potently neutralized Alpha and Delta, poorly neutralized Beta, and failed to neutralize Omicron BA.1 SARS-CoV-2 variants. Structural analysis of these mAbs in complex with trimeric spike protein showed that all three mAbs bivalently bind spike with two mAbs targeting class 1 and one targeting a class 4 receptor binding domain epitope. The immunogenetic makeup, structure, and function of these mAbs revealed specific molecular interactions associated with the potent multi-variant binding/neutralization efficacy. This knowledge shows how mutational combinations can affect the binding or neutralization of an antibody, which in turn relates to the efficacy of immune responses to emerging SARS-CoV-2 escape variants.
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Affiliation(s)
- Anamika Patel
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Sanjeev Kumar
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Lilin Lai
- Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Chennareddy Chakravarthy
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rajesh Valanparambil
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India; Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi 110016, India
| | - Kamalvishnu Gottimukkala
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Prashant Bajpai
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Dinesh Ravindra Raju
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA; Georgia Tech, Atlanta, GA 30332, USA
| | - Venkata Viswanadh Edara
- Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Meredith E Davis-Gardner
- Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Susanne Linderman
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Kritika Dixit
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Pragati Sharma
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Grace Mantus
- Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Narayanaiah Cheedarla
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hans P Verkerke
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pathology, Brigham and Women's Hospital, Boston, MA 02215, USA
| | - Filipp Frank
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Andrew S Neish
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - John D Roback
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Carl W Davis
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Jens Wrammert
- Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rafi Ahmed
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Mehul S Suthar
- Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Amit Sharma
- Structural Parasitology Group, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India.
| | - Kaja Murali-Krishna
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India; Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA.
| | - Anmol Chandele
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India.
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.
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4
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Das BK, Khan WA, Sreekumar SN, Ponraj K, Achary VMM, Reddy ES, Balasubramaniam D, Chandele A, Reddy MK, Arockiasamy A. Plant dehydroascorbate reductase moonlights as membrane integrated ion channel. Arch Biochem Biophys 2023; 741:109603. [PMID: 37084805 DOI: 10.1016/j.abb.2023.109603] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 04/03/2023] [Accepted: 04/17/2023] [Indexed: 04/23/2023]
Abstract
Plant dehydroascorbate reductases (DHARs) are only known as soluble antioxidant enzymes of the ascorbate-glutathione pathway. They recycle ascorbate from dehydroascorbate, thereby protecting plants from oxidative stress and the resulting cellular damage. DHARs share structural GST fold with human chloride intracellular channels (HsCLICs) which are dimorphic proteins that exists in soluble enzymatic and membrane integrated ion channel forms. While the soluble form of DHAR has been extensively studied, the existence of a membrane integrated form remains unknown. We demonstrate for the first time using biochemistry, immunofluorescence confocal microscopy, and bilayer electrophysiology that Pennisetum glaucum DHAR (PgDHAR) is dimorphic and is localized to the plant plasma membrane. In addition, membrane translocation increases under induced oxidative stress. Similarly, HsCLIC1 translocates more into peripheral blood mononuclear cells (PBMCs) plasma membrane under induced oxidative stress conditions. Moreover, purified soluble PgDHAR spontaneously inserts and conducts ions in reconstituted lipid bilayers, and the addition of detergent facilitates insertion. In addition to the well-known soluble enzymatic form, our data provides conclusive evidence that plant DHAR also exists in a novel membrane-integrated form. Thus, the structure of DHAR ion channel form will help gain deeper insights into its function across various life forms.
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Affiliation(s)
- Bhaba Krishna Das
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Wajahat Ali Khan
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Sreeshma Nellootil Sreekumar
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Department of Biotechnology, Jamia Hamdard University, New Delhi, 110062, India
| | - Kannapiran Ponraj
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - V Mohan Murali Achary
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India; Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, 110016, India
| | - D Balasubramaniam
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Anmol Chandele
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Malireddy K Reddy
- Crop Improvement Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Arulandu Arockiasamy
- Membrane Protein Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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5
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Patel A, Kumar S, Lai L, Chakravarthy C, Valanparambil R, Reddy ES, Gottimukkala K, Bajpai P, Raju DR, Edara VV, Davis-Gardner ME, Linderman S, Dixit K, Sharma P, Mantus G, Cheedarla N, Verkerke HP, Frank F, Neish AS, Roback JD, Davis CW, Wrammert J, Ahmed R, Suthar MS, Sharma A, Murali-Krishna K, Chandele A, Ortlund EA. Molecular basis of SARS-CoV-2 Omicron variant evasion from shared neutralizing antibody response. bioRxiv 2022:2022.10.24.513517. [PMID: 36324804 DOI: 10.1101/2022.10.13.512091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A detailed understanding of the molecular features of the neutralizing epitopes developed by viral escape mutants is important for predicting and developing vaccines or therapeutic antibodies against continuously emerging SARS-CoV-2 variants. Here, we report three human monoclonal antibodies (mAbs) generated from COVID-19 recovered individuals during first wave of pandemic in India. These mAbs had publicly shared near germline gene usage and potently neutralized Alpha and Delta, but poorly neutralized Beta and completely failed to neutralize Omicron BA.1 SARS-CoV-2 variants. Structural analysis of these three mAbs in complex with trimeric spike protein showed that all three mAbs are involved in bivalent spike binding with two mAbs targeting class-1 and one targeting class-4 Receptor Binding Domain (RBD) epitope. Comparison of immunogenetic makeup, structure, and function of these three mAbs with our recently reported class-3 RBD binding mAb that potently neutralized all SARS-CoV-2 variants revealed precise antibody footprint, specific molecular interactions associated with the most potent multi-variant binding / neutralization efficacy. This knowledge has timely significance for understanding how a combination of certain mutations affect the binding or neutralization of an antibody and thus have implications for predicting structural features of emerging SARS-CoV-2 escape variants and to develop vaccines or therapeutic antibodies against these.
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Affiliation(s)
- Anamika Patel
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Sanjeev Kumar
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Lilin Lai
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Chennareddy Chakravarthy
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rajesh Valanparambil
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, 110016, India
| | - Kamalvishnu Gottimukkala
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Prashant Bajpai
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Dinesh Ravindra Raju
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
- Georgia Tech, Atlanta, GA 30332, USA
| | - Venkata Viswanadh Edara
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Meredith E Davis-Gardner
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Susanne Linderman
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Kritika Dixit
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Pragati Sharma
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Grace Mantus
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Narayanaiah Cheedarla
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hans P Verkerke
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA 02215, USA
| | - Filipp Frank
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Andrew S Neish
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - John D Roback
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Carl W Davis
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Jens Wrammert
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rafi Ahmed
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Mehul S Suthar
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Amit Sharma
- Structural Parasitology Group, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Kaja Murali-Krishna
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Anmol Chandele
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
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6
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Patel A, Kumar S, Lai L, Chakravarthy C, Valanparambil R, Reddy ES, Gottimukkala K, Bajpai P, Raju DR, Edara VV, Davis-Gardner ME, Linderman S, Dixit K, Sharma P, Mantus G, Cheedarla N, Verkerke HP, Frank F, Neish AS, Roback JD, Davis CW, Wrammert J, Ahmed R, Suthar MS, Sharma A, Murali-Krishna K, Chandele A, Ortlund EA. Molecular basis of SARS-CoV-2 Omicron variant evasion from shared neutralizing antibody response. bioRxiv 2022:2022.10.24.513517. [PMID: 36324804 PMCID: PMC9628201 DOI: 10.1101/2022.10.24.513517] [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] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A detailed understanding of the molecular features of the neutralizing epitopes developed by viral escape mutants is important for predicting and developing vaccines or therapeutic antibodies against continuously emerging SARS-CoV-2 variants. Here, we report three human monoclonal antibodies (mAbs) generated from COVID-19 recovered individuals during first wave of pandemic in India. These mAbs had publicly shared near germline gene usage and potently neutralized Alpha and Delta, but poorly neutralized Beta and completely failed to neutralize Omicron BA.1 SARS-CoV-2 variants. Structural analysis of these three mAbs in complex with trimeric spike protein showed that all three mAbs are involved in bivalent spike binding with two mAbs targeting class-1 and one targeting class-4 Receptor Binding Domain (RBD) epitope. Comparison of immunogenetic makeup, structure, and function of these three mAbs with our recently reported class-3 RBD binding mAb that potently neutralized all SARS-CoV-2 variants revealed precise antibody footprint, specific molecular interactions associated with the most potent multi-variant binding / neutralization efficacy. This knowledge has timely significance for understanding how a combination of certain mutations affect the binding or neutralization of an antibody and thus have implications for predicting structural features of emerging SARS-CoV-2 escape variants and to develop vaccines or therapeutic antibodies against these.
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Affiliation(s)
- Anamika Patel
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Sanjeev Kumar
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Lilin Lai
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Chennareddy Chakravarthy
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rajesh Valanparambil
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India,Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, 110016, India
| | - Kamalvishnu Gottimukkala
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Prashant Bajpai
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Dinesh Ravindra Raju
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Georgia Tech, Atlanta, GA 30332, USA
| | - Venkata Viswanadh Edara
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Meredith E. Davis-Gardner
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Susanne Linderman
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Kritika Dixit
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Pragati Sharma
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India
| | - Grace Mantus
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Narayanaiah Cheedarla
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hans P. Verkerke
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA,Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02215, USA
| | - Filipp Frank
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Andrew S. Neish
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - John D. Roback
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Carl W. Davis
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Jens Wrammert
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rafi Ahmed
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Mehul S. Suthar
- Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Amit Sharma
- Structural Parasitology Group, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India,Correspondence: (E.A.O.), (A.C.), (K.M.K.), (A.S.)
| | - Kaja Murali-Krishna
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India,Department of Pediatrics, Emory National Primate Center, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA,Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA,Correspondence: (E.A.O.), (A.C.), (K.M.K.), (A.S.)
| | - Anmol Chandele
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi, 110067, India,Correspondence: (E.A.O.), (A.C.), (K.M.K.), (A.S.)
| | - Eric A. Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Correspondence: (E.A.O.), (A.C.), (K.M.K.), (A.S.)
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7
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Kumar S, Patel A, Lai L, Chakravarthy C, Valanparambil R, Reddy ES, Gottimukkala K, Davis-Gardner ME, Edara VV, Linderman S, Nayak K, Dixit K, Sharma P, Bajpai P, Singh V, Frank F, Cheedarla N, Verkerke HP, Neish AS, Roback JD, Mantus G, Goel PK, Rahi M, Davis CW, Wrammert J, Godbole S, Henry AR, Douek DC, Suthar MS, Ahmed R, Ortlund E, Sharma A, Murali-Krishna K, Chandele A. Structural insights for neutralization of Omicron variants BA.1, BA.2, BA.4, and BA.5 by a broadly neutralizing SARS-CoV-2 antibody. Sci Adv 2022; 8:eadd2032. [PMID: 36197988 PMCID: PMC9534492 DOI: 10.1126/sciadv.add2032] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In this study, by characterizing several human monoclonal antibodies (mAbs) isolated from single B cells of the COVID-19–recovered individuals in India who experienced ancestral Wuhan strain (WA.1) of SARS-CoV-2 during early stages of the pandemic, we found a receptor binding domain (RBD)–specific mAb 002-S21F2 that has rare gene usage and potently neutralized live viral isolates of SARS-CoV-2 variants including Alpha, Beta, Gamma, Delta, and Omicron sublineages (BA.1, BA.2, BA.2.12.1, BA.4, and BA.5) with IC
50
ranging from 0.02 to 0.13 μg/ml. Structural studies of 002-S21F2 in complex with spike trimers of Omicron and WA.1 showed that it targets a conformationally conserved epitope on the outer face of RBD (class 3 surface) outside the ACE2-binding motif, thereby providing a mechanistic insights for its broad neutralization activity. The discovery of 002-S21F2 and the broadly neutralizing epitope it targets have timely implications for developing a broad range of therapeutic and vaccine interventions against SARS-CoV-2 variants including Omicron sublineages.
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Affiliation(s)
- Sanjeev Kumar
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Anamika Patel
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Lilin Lai
- Department of Pediatrics, Emory University School of Medicine, Emory University Atlanta, GA 30322, USA
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Chennareddy Chakravarthy
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rajesh Valanparambil
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi-110 016, India
| | - Kamalvishnu Gottimukkala
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Meredith E. Davis-Gardner
- Department of Pediatrics, Emory University School of Medicine, Emory University Atlanta, GA 30322, USA
| | - Venkata Viswanadh Edara
- Department of Pediatrics, Emory University School of Medicine, Emory University Atlanta, GA 30322, USA
| | - Susanne Linderman
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Kaustuv Nayak
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Kritika Dixit
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Pragati Sharma
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Prashant Bajpai
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Vanshika Singh
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Filipp Frank
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Narayanaiah Cheedarla
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hans P. Verkerke
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
- Department of Pathology, Brigham and Women’s Hospital, Boston, MA 02215, USA
| | - Andrew S. Neish
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - John D. Roback
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Grace Mantus
- Department of Pediatrics, Emory University School of Medicine, Emory University Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Pawan Kumar Goel
- Shaheed Hasan Khan Mewat Government Medical College, Haryana, India
| | - Manju Rahi
- Division of Epidemiology and Communicable Diseases, Indian Council of Medical Research, New Delhi-110 029, India
| | - Carl W. Davis
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Jens Wrammert
- Department of Pediatrics, Emory University School of Medicine, Emory University Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Sucheta Godbole
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amy R. Henry
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Daniel C. Douek
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mehul S. Suthar
- Department of Pediatrics, Emory University School of Medicine, Emory University Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Rafi Ahmed
- Department of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Eric Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Amit Sharma
- ICMR-National Institute of Malaria Research, Dwarka, New Delhi-110 077, India
- Structural Parasitology Group, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
| | - Kaja Murali-Krishna
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
- Department of Pediatrics, Emory University School of Medicine, Emory University Atlanta, GA 30322, USA
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA
| | - Anmol Chandele
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, New Delhi-110 067, India
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8
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Nayak K, Gottimukkala K, Kumar S, Reddy ES, Edara VV, Kauffman R, Floyd K, Mantus G, Savargaonkar D, Goel PK, Arora S, Rahi M, Davis CW, Linderman S, Wrammert J, Suthar MS, Ahmed R, Sharma A, Murali-Krishna K, Chandele A. Characterization of neutralizing versus binding antibodies and memory B cells in COVID-19 recovered individuals from India. Virology 2021; 558:13-21. [PMID: 33706207 PMCID: PMC7934698 DOI: 10.1016/j.virol.2021.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [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: 10/14/2020] [Accepted: 02/12/2021] [Indexed: 12/16/2022]
Abstract
India is one of the most affected countries by COVID-19 pandemic; but little is understood regarding immune responses to SARS-CoV-2 in this region. Herein we examined SARS-CoV-2 neutralizing antibodies, IgG, IgM, IgA and memory B cells in COVID-19 recovered individual from India. While a vast majority of COVID-19 recovered individuals showed SARS-CoV-2 RBD-specific IgG, IgA and IgM antibodies (38/42, 90.47%; 21/42, 50%; 33/42, 78.57% respectively), only half of them had appreciable neutralizing antibody titers. RBD-specific IgG, but not IgA or IgM titers, correlated with neutralizing antibody titers and RBD-specific memory B cell frequencies. These findings have timely significance for identifying potential donors for plasma therapy using RBD-specific IgG assays as surrogate measurement for neutralizing antibodies in India. Further, this study provides useful information needed for designing large-scale studies towards understanding of inter-individual variation in immune memory to SARS CoV-2 natural infection for future vaccine evaluation and implementation efforts.
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Affiliation(s)
- Kaustuv Nayak
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Kamalvishnu Gottimukkala
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Sanjeev Kumar
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India; Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Venkata Viswanadh Edara
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Yerkes National Primate Research Center, Atlanta, GA 30329, USA
| | - Robert Kauffman
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Katharine Floyd
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Yerkes National Primate Research Center, Atlanta, GA 30329, USA
| | - Grace Mantus
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | | | - Pawan Kumar Goel
- Shaheed Hasan Khan Mewat Government Medical College, Nalhar, Mewat, Haryana, India
| | - Satyam Arora
- Department of Transfusion Medicine, Super Speciality Pediatric Hospital and Post Graduate Teaching Institute, Noida, UP, India
| | - Manju Rahi
- Division of Epidemiology and Communicable Diseases, Indian Council of Medical Research, New Delhi, India
| | - Carl W Davis
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Deptartment of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Susanne Linderman
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Jens Wrammert
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Mehul S Suthar
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA; Yerkes National Primate Research Center, Atlanta, GA 30329, USA
| | - Rafi Ahmed
- Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Deptartment of Microbiology and Immunology, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Amit Sharma
- ICMR-National Institute of Malaria Research, Dwarka, New Delhi, India; Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Kaja Murali-Krishna
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India; Emory Vaccine Center, Emory University, Atlanta, GA 30322, USA; Department of Pediatrics, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA.
| | - Anmol Chandele
- ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.
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9
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NAYAK KAUSTUV, Jain V, Kaur M, Khan N, Rai RC, Dixit K, Sagar R, Gupta S, Islamuddin M, Verma A, Maheshwari D, Aggarwal C, Chawla Y, Reddy ES, Panda H, Sharma P, Bhatnagar P, Singh P, Ratageri VH, Chandele A, Ray P, Muralikrishna K. Human immunity to chikungunya infection. The Journal of Immunology 2020. [DOI: 10.4049/jimmunol.204.supp.249.3] [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] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Chikungunyna virus is expanding globally and continue to cause major public health threat to Indian populations. Vaccine efforts are underway, and it is hoped that these will eventually progress to human evaluation. However, currently we have little understanding of the phenotypes and functions of the human T cells in chikungunya patients, a knowledge that is essential for improving vaccine design/testing and evaluation efforts. Here, we provide a detailed analysis of the CD8 T cell responses in chikungunya patients from India. We found that CD38+ HLADR+ CD8 T cell subset expanded dramatically in chikungunya febrile patients with frequencies averaging about 20% of the total CD8 T cells, and reaching as high as 50% of the CD8 T cells in some patients. The frequencies of these activated CD8 T cells were substantially low and barely above background levels in afebrile patients reporting to the clinic with persistent arthralgia/arthritis that was lasting for more than 30 days. These massively expanding CD8 T cells observed in the acute febrile patients were highly proliferating (KI67 ), robustly expressing markers indicative strong Th1 differentiation (T-bet), cytotoxic functions (Perforin) and inflammatory/synovial tissue homing characteristics (CX3CR1 and CXCR4). Interestingly, antigen-stimulation mediated IFN-g producing functions of these cells was highly compromized, reminiscent of the “cytokine stunned” phenotype. Taken together, these results suggest that these highly differentiated effector CD8 T cell that were massively expanding during acute chikungunya febrile infection might be involved in protection by homing to infected tissues and eliminating infected targets rather than causing inflammation.
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Affiliation(s)
- KAUSTUV NAYAK
- 1International Centre for Genetic Engineering and Biotechnology, India
| | - Vineet Jain
- 2Hamdard Institute of Medical Sciences and Research, India
| | - Manpreet Kaur
- 1International Centre for Genetic Engineering and Biotechnology, India
| | | | | | - Kritika Dixit
- 1International Centre for Genetic Engineering and Biotechnology, India
| | | | | | | | - Anil Verma
- 4All India Institute of Medical Science, New Delhi, India
| | - Deepti Maheshwari
- 1International Centre for Genetic Engineering and Biotechnology, India
| | - Charu Aggarwal
- 1International Centre for Genetic Engineering and Biotechnology, India
| | - Yadya Chawla
- 1International Centre for Genetic Engineering and Biotechnology, India
| | | | - Harekrushna Panda
- 1International Centre for Genetic Engineering and Biotechnology, India
| | - Pragati Sharma
- 1International Centre for Genetic Engineering and Biotechnology, India
| | - Priya Bhatnagar
- 1International Centre for Genetic Engineering and Biotechnology, India
| | - Prabhat Singh
- 1International Centre for Genetic Engineering and Biotechnology, India
| | | | - Anmol Chandele
- 1International Centre for Genetic Engineering and Biotechnology, India
| | | | - Kaja Muralikrishna
- 1International Centre for Genetic Engineering and Biotechnology, India
- 6Emory Vaccine Center, Emory University School of Medicine
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10
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Nayak K, Jain V, Kaur M, Khan N, Gottimukkala K, Aggarwal C, Sagar R, Gupta S, Rai RC, Dixit K, Islamuddin M, Khan WH, Verma A, Maheshwari D, Chawla YM, Reddy ES, Panda H, Sharma P, Bhatnagar P, Singh P, Raghavendhar B S, Patel AK, Ratageri VH, Chandele A, Ray P, Murali-Krishna K. Antibody response patterns in chikungunya febrile phase predict protection versus progression to chronic arthritis. JCI Insight 2020; 5:130509. [PMID: 32155134 DOI: 10.1172/jci.insight.130509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 05/24/2019] [Accepted: 03/04/2020] [Indexed: 11/17/2022] Open
Abstract
Chikungunya virus (CHIKV) infection causes acute febrile illness in humans, and some of these individuals develop a debilitating chronic arthritis that can persist for months to years for reasons that remain poorly understood. In this study from India, we characterized antibody response patterns in febrile chikungunya patients and further assessed the association of these initial febrile-phase antibody response patterns with protection versus progression to developing chronic arthritis. We found 5 distinct patterns of the antibody responses in the febrile phase: no CHIKV binding or neutralizing (NT) antibodies but PCR positive, IgM alone with no NT activity, IgM alone with NT activity, IgM and IgG without NT activity, and IgM and IgG with NT activity. A 20-month follow-up showed that appearance of NT activity regardless of antibody isotype or appearance of IgG regardless of NT activity during the initial febrile phase was associated with a robust protection against developing chronic arthritis in the future. These findings, while providing potentially novel insights on correlates of protective immunity against chikungunya-induced chronic arthritis, suggest that qualitative differences in the antibody response patterns that have evolved during the febrile phase can serve as biomarkers that allow prediction of protection or progression to chronic arthritis in the future.
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Affiliation(s)
- Kaustuv Nayak
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Vineet Jain
- Department of Medicine, Hamdard Institute of Medical Sciences and Research (HIMSAR), Jamia Hamdard, New Delhi, India
| | - Manpreet Kaur
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Naushad Khan
- Department of Biotechnology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi, India
| | - Kamalvishnu Gottimukkala
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Charu Aggarwal
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Rohit Sagar
- Department of Biotechnology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi, India
| | - Shipra Gupta
- Department of Biotechnology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi, India
| | - Ramesh Chandra Rai
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Kritika Dixit
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Mohammad Islamuddin
- Department of Biotechnology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi, India
| | - Wajihul Hasan Khan
- Department of Biotechnology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi, India
| | - Anil Verma
- Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Deepti Maheshwari
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Yadya M Chawla
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Elluri Seetharami Reddy
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Harekrushna Panda
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Pragati Sharma
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Priya Bhatnagar
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Prabhat Singh
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Siva Raghavendhar B
- Kusuma School of Biological Sciences, Indian Institute of Technology (IIT), New Delhi, India
| | - Ashok Kumar Patel
- Kusuma School of Biological Sciences, Indian Institute of Technology (IIT), New Delhi, India
| | - Vinod H Ratageri
- Department of Pediatrics, Karnataka Institute of Medical Sciences (KIMS), Hubli, Karnataka, India
| | - Anmol Chandele
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India
| | - Pratima Ray
- Department of Biotechnology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi, India
| | - Kaja Murali-Krishna
- ICGEB-Emory Vaccine Centre, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi, India.,Emory Vaccine Center and.,Department of Pediatrics, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, Georgia, USA
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11
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Du J, Cai X, Yao J, Ding X, Wu Q, Pei S, Jiang K, Zhang Y, Wang W, Shi Y, Lai Y, Shen J, Teng M, Huang H, Fei Q, Reddy ES, Zhu J, Jin C, Yao X. The mitotic checkpoint kinase NEK2A regulates kinetochore microtubule attachment stability. Oncogene 2008; 27:4107-14. [PMID: 18297113 DOI: 10.1038/onc.2008.34] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Loss or gain of whole chromosome, the form of chromosome instability commonly associated with cancers is thought to arise from aberrant chromosome segregation during cell division. Chromosome segregation in mitosis is orchestrated by the interaction of kinetochores with spindle microtubules. Our studies show that NEK2A is a kinetochore-associated protein kinase essential for faithful chromosome segregation. However, it was unclear how NEK2A ensures accurate chromosome segregation in mitosis. Here we show that NEK2A-mediated Hec1 (highly expressed in cancer) phosphorylation is essential for faithful kinetochore microtubule attachments in mitosis. Using phospho-specific antibody, our studies show that NEK2A phosphorylates Hec1 at Ser165 during mitosis. Although such phosphorylation is not required for assembly of Hec1 to the kinetochore, expression of non-phosphorylatable mutant Hec1(S165) perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. Our in vitro reconstitution experiment demonstrated that Hec1 binds to microtubule in low affinity and phosphorylation by NEK2A, which prevents aberrant kinetochore-microtubule connections in vivo, increases the affinity of the Ndc80 complex for microtubules in vitro. Thus, our studies illustrate a novel regulatory mechanism in which NEK2A kinase operates a faithful chromosome attachment to spindle microtubule, which prevents chromosome instability during cell division.
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Affiliation(s)
- J Du
- Hefei National Laboratory for Physical Sciences at Micro-scale, University of Science and Technology of China, Hefei, China
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12
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Fujimura Y, Siddique H, Lee L, Rao VN, Reddy ES. EWS-ATF-1 chimeric protein in soft tissue clear cell sarcoma associates with CREB-binding protein and interferes with p53-mediated trans-activation function. Oncogene 2001; 20:6653-9. [PMID: 11709699 DOI: 10.1038/sj.onc.1204684] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2001] [Revised: 05/23/2001] [Accepted: 05/31/2001] [Indexed: 11/09/2022]
Abstract
The recurrent t(12;22) (q13;q12) chromosomal translocation associated with soft tissue clear cell sarcoma results in a chimeric protein EWS-ATF-1 that acts as a constitutive transcriptional activator. The CBP/p300 transcriptional coactivator, which links various transcriptional factors to basal transcription apparatus, participates in transcriptional activation, growth and cell cycle control and differentiation. In this study, we show that EWS-ATF-1 associates constitutively with CBP both in vitro and in vivo. Both EWS and ATF-1 fusion domains are needed for this interaction. Here, we demonstrate that EWS-ATF-1 represses p53/CBP-mediated trans-activation function. Overexpression of CBP can counteract this repressive effect of EWS-ATF-1. Taken together, these findings suggest that one of the mechanisms by which EWS-ATF-1 may cause tumors is through targeting CBP/p300 resulting in the loss of function of p53. This novel mechanism may be responsible for the development of these and other related solid tumors.
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MESH Headings
- Blotting, Western
- Dose-Response Relationship, Drug
- Genes, p53
- Glutathione Transferase/metabolism
- Humans
- Models, Genetic
- Nuclear Proteins/metabolism
- Oncogene Proteins, Fusion/metabolism
- Plasmids/metabolism
- Precipitin Tests
- Protein Binding
- Protein Structure, Tertiary
- Sarcoma, Clear Cell/genetics
- Sarcoma, Clear Cell/metabolism
- Soft Tissue Neoplasms/genetics
- Soft Tissue Neoplasms/metabolism
- Trans-Activators/metabolism
- Transcription Factors
- Transcription, Genetic
- Transcriptional Activation
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- Y Fujimura
- Program of Cancer Genetics, Department of Biochemistry, School of Medicine, MCP Hahnemann University, Broad and Vine, Philadelphia, PA 19102, USA
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13
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Chai Y, Chipitsyna G, Cui J, Liao B, Liu S, Aysola K, Yezdani M, Reddy ES, Rao VN. c-Fos oncogene regulator Elk-1 interacts with BRCA1 splice variants BRCA1a/1b and enhances BRCA1a/1b-mediated growth suppression in breast cancer cells. Oncogene 2001; 20:1357-67. [PMID: 11313879 DOI: 10.1038/sj.onc.1204256] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2000] [Revised: 01/05/2001] [Accepted: 01/09/2001] [Indexed: 01/19/2023]
Abstract
Elk-1, a c-Fos protooncogene regulator, which belongs to the ETS-domain family of transcriptional factors, plays an important role in the induction of immediate early gene expression in response to a variety of extracellular signals. In this study, we demonstrate for the first time the in vitro and in vivo interaction of Elk-1 with BRCA1 splice variants BRCA1a and BRCA1b using GST-pull down assays, co-imunoprecipitations/Western blot analysis of cell extracts from breast cancer cells and mammalian two-hybrid assays. We have localized the BRCA1 interaction domain of Elk-1 protein to the conserved ETS domain, a motif involved in DNA binding and protein-protein interactions. We also observed binding of BRCA1 proteins to other ETS-domain transcription factors SAP1, ETS-1, ERG-2 and Fli-1 but not to Elk-1 splice variant DeltaElk-1 and c-Fos protooncogene. Both BRCA1a and BRCA1b splice variants function as growth suppressors of human breast cancer cells. Interestingly, our studies reveal that although both Elk-1 and SAP-1 are highly homologous members of a subfamily of ETS domain proteins called ternary complex factors, it is only Elk-1 but not SAP-1 that can augment the growth suppressive function of BRCA1a/1b proteins in breast cancer cells. Thus Elk-1 could be a potential downstream target of BRCA1 in its growth control pathway. Furthermore, we have observed inhibition of c-Fos promoter activity in BRCA1a transfected stable breast cancer cells and over expression of BRCA1a/1b attenuates MEK-induced SRE activation in vivo. These results demonstrate for the first time a link between the growth suppressive function of BRCA1a/1b proteins and signal transduction pathway involving Elk-1 protein. All these results taken together suggest that one of the mechanisms by which BRCA1a/1b proteins function as growth/tumor suppressors is through inhibition of the expression of Elk-1 target genes like c-Fos.
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Affiliation(s)
- Y Chai
- Department of Medicine, Program of Cancer Genetics, Cancer Center, MCP Hahnemann University, 245 North 15th Street, New College Building, M.S. 481, Philadelphia, Pennsylvania 19102, USA
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14
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Zou JP, Hirose Y, Siddique H, Rao VN, Reddy ES. Structure and expression of variant BRCA2a lacking the transactivation domain. Oncol Rep 1999. [DOI: 10.3892/or.6.2.437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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15
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Zou JP, Hirose Y, Siddique H, Rao VN, Reddy ES. Structure and expression of variant BRCA2a lacking the transactivation domain. Oncol Rep 1999; 6:437-40. [PMID: 10023017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
BRCA1 and BRCA2 are tumor suppressor genes shown to be involved in 90% of familial breast cancers and also known to be involved in ovarian and prostate cancers. Both BRCA1 and BRCA2 gene products are regulated in a cell cycle-dependent manner and have potential transactivation function. Here, we show that BRCA2 undergoes differential splicing giving rise to a novel variant protein BRCA2a, lacking putative transcriptional activation domain. Both BRCA2a and BRCA2 are expressed at high levels in thymus and testis but moderate levels in mammary gland and prostate suggesting that BRCA2a and BRCA2 may have a role in the development and differentiation of these tissues.
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Affiliation(s)
- J P Zou
- Division of Cancer Genetics, Department of Human Genetics, MS 481, Allegheny University of the Health Sciences, Broad and Vine, Philadelphia, PA 19102, USA
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16
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Abstract
The proto-oncogene Fli-1, a member of Ets family is rearranged or activated through proviral integration in erythroleukemias, induced by Friends' Murine Leukemia Virus. The DNA binding domain (ETS domain) of Fli-1 is fused to the RNA binding domain of EWS by t(11q24:22q12) chromosomal translocation in Ewing's sarcoma and primitive neuroectodermal tumors. Screening of human cDNA libraries has identified two different 5'-termini and alternatively spliced forms of the human Fli-1 gene (Fli-1b), suggesting the possible existence of two independent promoters. The genomic sequence adjacent to the alternate exon of human Fli-1b gene shows functional promoter activity when cloned in promoter-less CAT expression vector and transfected into QT-6 cells. The transcription initiation (CAP) site and minimum promoter region necessary for function were localized. The 5'-flanking regions of human Fli-1b and mouse Fli-1 show 80% homology suggesting conserved promoter regulatory elements. The Fli-1b 5'-flanking sequence lacks canonical TATA or CCAAT boxes but contains a partially conserved TATA-like sequence at position 242. Several transcription factor binding sequences like ATF/CREB, E2A-PBX1, EBP, PEA-3, ETS-2, Sp-1, c-Myc, TBP, GATA-1 and Oct-3 were conserved in the promoter sequence. Functional promoter assays revealed that Fli-1b promoter shows very strong transcriptional activation compared to Fli-1 promoter. We also showed that variant Fli-1b has transcriptional activation properties similar to those of Fli-1. Fli-1b and Fli-1 show differential expression in various hematopoietic cell lines. This differential expression and promoter activities of Fli-1 and Fli-1b suggests that several mechanisms are involved in Fli-1 gene regulation which are mediated by many transcription factors.
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MESH Headings
- Alternative Splicing/genetics
- Amino Acid Sequence
- Animals
- Base Sequence
- Binding Sites/genetics
- Chloramphenicol O-Acetyltransferase/genetics
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Gene Expression/genetics
- Humans
- Molecular Sequence Data
- Promoter Regions, Genetic/genetics
- Proto-Oncogene Mas
- Proto-Oncogene Protein c-fli-1
- Proto-Oncogene Proteins
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sensitivity and Specificity
- Sequence Analysis, DNA
- Sequence Deletion/genetics
- Sequence Homology, Nucleic Acid
- TATA Box/genetics
- Trans-Activators/genetics
- Trans-Activators/physiology
- Transcription, Genetic/genetics
- Transfection
- Tumor Cells, Cultured/cytology
- Tumor Cells, Cultured/metabolism
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Affiliation(s)
- P D Dhulipala
- Department of Human Genetics, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA
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17
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Abstract
Elk-1, an ets related gene codes for at least two splice variants Elk-1, which regulates c-fos transcription and deltaElk-1, both of which function as transcriptional activators. To investigate the role of Elk-1 and deltaElk-1 proteins in apoptosis; we have developed rat fibroblast cell lines and human breast cancer cell lines expressing Elk-1 and deltaElk-1. The expression of Elk-1 and deltaElk-1 proteins in the Elk-1/deltaElk-1 transfectants were analysed by immunofluorescence, immunohistochemistry, and Western blot analysis. The Elk-1 unlike deltaElk-1 transfectants showed a shortened and flattened morphology compared to the parental cells. We have found that calcium ionophore treatment of Rat-1 Elk-1, MCF-7 Elk-1, Rat-1 deltaElk-1 and MCF-7 deltaElk-1 transfectants resulted in programmed cell death. These results indicate that constitutive expression of Elk-1 and deltaElk-1 proteins triggers apoptosis in Rat-1 fibroblasts and breast cancer cells when treated with calcium ionophore.
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Affiliation(s)
- N Shao
- Department of Human Genetics, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA
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18
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Pereira DS, Dorrell C, Ito CY, Gan OI, Murdoch B, Rao VN, Zou JP, Reddy ES, Dick JE. Retroviral transduction of TLS-ERG initiates a leukemogenic program in normal human hematopoietic cells. Proc Natl Acad Sci U S A 1998; 95:8239-44. [PMID: 9653171 PMCID: PMC20960 DOI: 10.1073/pnas.95.14.8239] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Many chimeric oncogenes have been identified by virtue of the association between chromosomal translocation and specific human leukemias. However, the biological mechanism by which these oncogenes disrupt the developmental program of normal human hematopoietic cells during the initiation of the leukemogenic process is poorly understood due to the absence of an appropriate experimental system to study their function. Here, we report that retroviral transduction of TLS-ERG, a myeloid leukemia-associated fusion gene, to human cord blood cells results in altered myeloid and arrested erythroid differentiation and a dramatic increase in the proliferative and self-renewal capacity of transduced myeloid progenitors. Thus, TLS-ERG expression alone induced a leukemogenic program that exhibited similarities to the human disease associated with this translocation. These results provide an experimental examination of the early stages of the human leukemogenic process induced by a single oncogene and establish a paradigm to functionally assay putative leukemogenic genes in normal human hematopoietic cells.
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Affiliation(s)
- D S Pereira
- Department of Genetics, Research Institute, Hospital for Sick Children, and Department of Medical and Molecular Genetics, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
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19
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Abstract
The tumor suppressor gene BRCA1, is a nuclear phosphoprotein which associates with RNA polymerase II holoenzyme. CBP is a component of the holoenzyme. Previously, we have characterized two new BRCA1 splice variants BRCA1a/p110 and BRCA1b/p100. In the present study, the carboxy-terminal domain of transcription factor CBP interacts both in vivo and in vitro with full length BRCA1a and BRCA1b proteins as demonstrated by mammalian two- hybrid assays, co-immunoprecipitation/western blot studies, GST binding assays and histone acetyl transferase (HAT) assays of BRCA1 immunoprecipitates from human breast cancer cells. Our results suggest that one of the mechanisms by which BRCA1 proteins function is through recruitment of CBP associated HAT/FAT (transcription factor acetyl-transferase) activity for acetylation of either themselves or general transcription factors or both to specific promoters resulting in transcriptional activation.
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Affiliation(s)
- J Q Cui
- Division of Cancer Genetics, Department of Human Genetics, Allegheny University of the Health Sciences, M.S. 481, New College Building, Broad and Vine Streets, Philadelphia, PA 19102, USA
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20
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Abstract
The breast and ovarian cancer susceptibility gene BRCA1, is a nuclear phosphoprotein which functions as a tumor suppressor in human breast cancer cells. BRCA1 protein contains an amino-terminal zinc finger motif and a carboxy-terminal acidic region. Recently, the carboxy-terminal region of BRCA1 and the amino-terminal region of BRCA2 proteins were shown to function as transactivation domains when fused to GAL4 DNA binding domain. We have recently isolated and characterized two new naturally occurring variants of BRCA1 (BRCA1a/p110 and BRCA1b/p100) which are phosphoproteins containing phosphotyrosine that associate with E2F transcriptional factors, cyclins and cyclin dependent kinases indicating a role for BRCA1 proteins in cell-cycle regulation. Here we show for the first time that the amino-terminal region of BRCA1a (BNT) but not BRCA1b can also function as a transcriptional activator when fused to GAL4 DNA binding domain. Thus, BRCA1/1a proteins contain two autonomous transcriptional activation domains, one at the amino-terminal region (BNT) and the other at the carboxy-terminal region (BCT). BRCA1b retains only the BCT domain since it has lost part of the potential BNT domain as a result of alternative splicing. Our results also suggest the presence of an inhibitory domain at the carboxy terminal region of BRCA1 and BRCA1a proteins (BID). Thus, BRCA1b protein may function as a dominant negative variant that could regulate the transcriptional activity of BRCA1/BRCA1a proteins and hence may serve as a marker for identifying individuals with greater potential for developing breast cancer. It may be possible that loss of transcriptional activation or protein-protein interactions in patients with mutations in the amino terminal zinc finger domain could deprive the cell of an important mechanism for regulating cell proliferation leading to the development of breast cancer.
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Affiliation(s)
- J Q Cui
- Division of Cancer Genetics, Department of Human Genetics, Allegheny University of the Health Sciences, M.S. 481, New College Building, Broad and Vine Streets, Philadelphia, PA 19102, USA
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21
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Abstract
Patients carrying mutations in BRCA1 or BRCA2 tumor suppressor genes have shown to have high risk in developing breast and ovarian cancers. Two potential functions of BRCA2 were proposed which includes role in the regulation of transcription and also in DNA repair. Forty-five-amino acid region encoded by exon 3 of BRCA2 was shown to have transcriptional activation function. Recent studies of the several enzymes involved in acetylation and deacetylation of histone residues have revealed a possible relationship between gene transcriptional activation and histone acetylation. Since BRCA2 appear to function as a transcriptional factor, we have tested for Histone acetyl transferase (HAT) activity of BRCA2. Here, we present evidence that BRCA2 has intrinsic HAT activity, which maps to the amino-terminal region of BRCA2. Our results demonstrate that BRCA2 proteins acetylate primarily H3 and H4 of free histones. These observations suggest that HAT activity of BRCA2 may play an important role in the regulation of transcription and tumor suppressor function.
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Affiliation(s)
- H Siddique
- Department of Human Genetics, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA
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22
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Wang H, Shao N, Ding QM, Cui J, Reddy ES, Rao VN. BRCA1 proteins are transported to the nucleus in the absence of serum and splice variants BRCA1a, BRCA1b are tyrosine phosphoproteins that associate with E2F, cyclins and cyclin dependent kinases. Oncogene 1997; 15:143-57. [PMID: 9244350 DOI: 10.1038/sj.onc.1201252] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BRCA1, a familial breast and ovarian cancer susceptibility gene encodes nuclear phosphoproteins that function as tumor suppressors in human breast cancer cells. Previously, we have shown that overexpression of a BRCA1 splice variant BRCA1a accelerates apoptosis in human breast cancer cells. In an attempt to determine whether the subcellular localization of BRCA1 is cell cycle regulated, we have studied the subcellular distribution of BRCA1 in asynchronous and growth arrested normal, breast and ovarian cancer cells using different BRCA1 antibodies by immunofluorescence and immunohistochemical staining. Upon serum starvation of NIH3T3, some breast and ovarian cancer cells, most of the BRCA1 protein redistributed to the nucleus revealing a new type of regulation that may modulate the activity of BRCA1 gene. We have also characterized two new variant BRCA1 proteins (BRCA1a/p110 and BRCA1b/ p100) which are phosphoproteins containing phosphotyrosine. Immunofluorescence and Western blotting analysis indicate cytoplasmic and nuclear localization of BRCA1a and BRCA1b proteins. To elucidate the biological function of BRCA1, we created a bacterial fusion protein of glutathione-transferase (GST) and BRCA1 zinc finger domain and detected two cellular proteins with molecular weights of approximately 32 and 65 kD, one of which contains phosphotyrosine designated p32 and p65 BRCA1 interacting proteins (BIP) that specifically interact with BRCA1. Western blot analysis of BIP with cyclins/CDKs and E2F antisera indicated association with cdc2, cdk2, cdk4, cyclin B, cyclin D, cyclin A and E2F-4 but not with cdk3, cdk5, cdk6, E2F-1, E2F-2, E2F-3, E2F-5 and cyclin E. Furthermore, we have also demonstrated a direct interaction of in vitro translated BRCA1a and BRCA1b proteins with recombinant cyclin A, cyclin B1, cyclin D1, cdc2, cdk2 and E2F fusion proteins in vitro. Taken together these results seem to suggest that BRCA1 could be an important negative regulator of cell cycle that functions through interaction with E2F transcriptional factors and phosphorylation by cyclins/cdk complexes with the zinc ring finger functioning as a major protein-protein interaction domain. If the interactions we observe in vitro is also seen in vivo then it may be possible that lack or impaired binding of the disrupted BRCA1 proteins to E2F, cyclins/CDKs in patients with mutations in the zinc finger domain could deprive the cell of an important mechanism for braking cell proliferation leading to the development of breast and ovarian cancers.
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Affiliation(s)
- H Wang
- Department of Human Genetics, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA
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23
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Yi H, Fujimura Y, Ouchida M, Prasad DD, Rao VN, Reddy ES. Inhibition of apoptosis by normal and aberrant Fli-1 and erg proteins involved in human solid tumors and leukemias. Oncogene 1997; 14:1259-68. [PMID: 9178886 DOI: 10.1038/sj.onc.1201099] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Two ets family members, namely erg and Fli-1 are fused with two EWS family members namely EWS and TLS/FUS as a result of chromosome translocation in human solid tumors and leukemias. EWS-erg and EWS-Fli-1, which are involved in greater than 95% of Ewing family of tumors, were shown to function as transcriptional activators. TLS/FUS-erg, which is involved in human myeloid leukemias also functions as a transcriptional activator. Expression of these fusion proteins (EWS-erg and EWS-Fli-1) are shown to be essential for maintaining the oncogenic and tumorigenic properties of tumor cells. Cancer is thought to be caused not only by uncontrolled cell proliferation but also by deregulation of programmed cell death. Therefore, we have studied the role of normal (Fli-1 and erg) and aberrant fusion proteins (EWS-erg, EWS-Fli-1 and TLS/FUS-erg) in apoptosis. We have found that expression of normal (Fli-1 and erg) and aberrant fusion proteins inhibit the apoptosis of NIH3T3 cells induced by either serum deprivation or by treatment with calcium ionophore. We have also observed similar suppression of apoptosis in Ewing's sarcoma cells expressing EWS-Fli-1 and EWS-erg proteins suggesting that these fusion proteins may be responsible for the decreased ability of these tumor cells to undergo apoptosis. Inhibition of the expression of these aberrant fusion proteins by antisense RNA technique resulted in increased susceptibility to apoptosis leading to the death of tumor cells. Therefore, our results suggest that one can use therapeutic agents which can down regulate the expression of fusion proteins in combination with chemotherapeutic agents as an effective treatment for these human solid tumors and leukemias.
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Affiliation(s)
- H Yi
- Department of Human Genetics, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA
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24
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Rao VN, Shao N, Ahmad M, Reddy ES. Antisense RNA to the putative tumor suppressor gene BRCA1 transforms mouse fibroblasts. Oncogene 1996; 12:523-8. [PMID: 8637708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Recently, BRCA1, a familial breast and ovarian cancer susceptible gene has been cloned and shown to be either lost or mutated in families with breast and ovarian cancers. BRCA1 has been postulated to encode a tumor suppressor, a protein that acts as a negative regulator of tumor growth. We have characterized the BRCA1 gene products by Western blot and immunoprecipitation analysis in mouse and tumor cells. Multiple BRCA1 polypeptides of approximately 225, 185, 160, 145, 100, 52 and 38 kD were identified in these cells. BRCA1 proteins were found to be localized mainly in the nucleus of normal Rat1 cells and human breast cancer cells. In order to understand the role of BRCA1 in cell transformation, we have established a stable NIH3T3 cell line expressing BRCA1 antisense RNA. The inhibition of expression of endogenous BRCA1 protein was detected in NIH3T3 transfectants by Western blot analysis. The antisense BRCA1 expressing NIH3T3 cells showed accelerated growth rate, anchorage independent growth and tumorigenicity in nude mice unlike the parental and sense transfectants. These results provide the first direct biological evidence for the possible function of BRCA1 as a tumor suppressor gene.
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Affiliation(s)
- V N Rao
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania 19107-5541, USA
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25
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Fujimura Y, Ohno T, Siddique H, Lee L, Rao VN, Reddy ES. The EWS-ATF-1 gene involved in malignant melanoma of soft parts with t(12;22) chromosome translocation, encodes a constitutive transcriptional activator. Oncogene 1996; 12:159-67. [PMID: 8552387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Molecular characterization of malignant melanoma of soft parts or soft tissue clear cell sarcoma which shares t(12;22) chromosome translocation revealed fusion of EWS with a transcriptional factor gene ATF-1. The EWS gene, which encodes an RNA binding protein, was also shown to be involved in Ewing sarcoma, related primitive neuroectodermal tumors and desmoplastic small round cell tumors. In order to understand the functional role of EWS-ATF-1 chimeric protein in human solid tumors, we have cloned the aberrant human ATF-1 (EWS-ATF-1) cDNA and studied its DNA binding, transcriptional activation properties and compared with normal ATF-1 protein. Our results demonstrate that EWS-ATF-1 binds weakly to DNA in vitro but functions as an efficient constitutive transcriptional activator unlike the normal ATF-1 which needs to be induced with cAMP. Deletion analysis revealed that EWS-fusion domain functions as a regulatory domain for the transcriptional activation properties of EWS-ATF-1 chimeric protein. Deletion of leucine zipper domain results in a loss of transcriptional activation of EWS-ATF-1 chimeric protein suggesting that protein-protein interaction play a role in the transcriptional activation properties of EWS-ATF-1. We demonstrate that EWS-fusion domain negatively regulates the DNA binding activity of EWS-ATF-1 chimeric protein. Therefore replacement of part of the amino-terminal kinase regulatory domain of ATF-1 protein with EWS regulatory domain results in an altered DNA binding, protein-protein interactions and transcriptional activation properties of EWS-ATF-1 causing deregulated gene expression which may be responsible for the genesis of t(12;22) chromosome translocation-bearing human solid tumors. Targeting the transcriptional cofactors (CBP, etc) by EWS-fusion proteins could be one of the mechanisms of activation of EWS-fusion proteins in human neoplasia.
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Affiliation(s)
- Y Fujimura
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, PA 19107-5541, USA
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26
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Ouchida M, Ohno T, Fujimura Y, Rao VN, Reddy ES. Loss of tumorigenicity of Ewing's sarcoma cells expressing antisense RNA to EWS-fusion transcripts. Oncogene 1995; 11:1049-54. [PMID: 7566963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cytogenetic analysis of Ewing's sarcoma, primitive neuroectodermal tumors and Askin tumors revealed characteristic translocations t(11;22) or t(21;22). Molecular analysis of these translocations revealed 5'-region of EWS gene (from band 22q12) is fused to the 3'-region of either Fli-1 gene (from band 11q24) or erg gene (from band 21q22). Functional characterization of the EWS-Fli-1 and EWS-erg chimeric proteins suggested that they function as transcriptional activators. In order to develop therapeutic agents, it is essential to know whether expression of the EWS-fusion gene products is coupled to tumorigenicity of Ewing's sarcoma cells and if targeting the EWS-fusion products results in loss of tumorigenicity of Ewing's sarcoma cells. For this reason, we have made stable Ewing's sarcomas expressing antisense EWS-Fli-1 or EWS-erg expression plasmids. Expression of antisense EWS fusion transcripts resulted in a significant loss of endogenous EWS-Fli-1 and EWS-erg proteins in Ewing's sarcoma cells. These cells expressing antisense EWS fusion transcripts showed loss of anchorage independent growth and tumorigenicity in nude mice unlike the parental Ewing's sarcoma cells. These results demonstrate the necessity of a certain threshold level of expression of EWS-fusion products in the clonogenicity and tumorigenicity of Ewing's sarcoma cells and therefore emphasizes the importance of targeting the EWS-fusion products as a therapy for Ewing family of tumors.
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Affiliation(s)
- M Ouchida
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107-5541, USA
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27
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Prasad DD, Ouchida M, Lee L, Rao VN, Reddy ES. TLS/FUS fusion domain of TLS/FUS-erg chimeric protein resulting from the t(16;21) chromosomal translocation in human myeloid leukemia functions as a transcriptional activation domain. Oncogene 1994; 9:3717-29. [PMID: 7970732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
EWS and TLS/FUS genes, which code for RNA binding proteins are involved in a wide variety of human solid tumors. The TLS/FUS gene is involved both in human myxoid liposarcomas which carry a characteristic chromosomal translocation, t(12;16)(q13;p11) and in human myeloid leukemias with recurrent chromosomal translocation, t(16;21)(p11:q22). The TLS/FUS gene is fused to a transcriptional repressor, CHOP (in human myxoid liposarcomas) or transcriptional activator, erg (in human myeloid leukemias). To understand better the functional role of TLS/FUS-erg in human myeloid leukemias, we have cloned the TLS/FUS and TLS/FUS-erg cDNAs and studied the functional properties of their gene products. TLS/FUS protein binds to RNA in vitro and shows preferential binding to poly G. Both the amino- and the carboxy- terminal regions of TLS/FUS containing the conserved RNA binding motifs are needed for poly G specific RNA binding activity. The TLS/FUS fusion domain (TFD) appears to regulate the DNA binding activity of TLS/FUS-erg chimeric protein which shows weaker transcriptional activation properties compared to normal erg proteins. Mutational analysis of the TLS/FUS-erg chimeric protein reveals TFD to function as a transcriptional activation domain thus replacing the amino terminal transcriptional activation domain of the erg protein. Therefore alterations in both DNA binding and transcriptional activation properties of aberrant erg proteins may be responsible for the genesis of t(16;21) chromosomal translocation-bearing human myeloid leukemias.
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Affiliation(s)
- D D Prasad
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, PA 19107-5541
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28
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Ohno T, Ouchida M, Lee L, Gatalica Z, Rao VN, Reddy ES. The EWS gene, involved in Ewing family of tumors, malignant melanoma of soft parts and desmoplastic small round cell tumors, codes for an RNA binding protein with novel regulatory domains. Oncogene 1994; 9:3087-97. [PMID: 8084618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The EWS gene, which maps to band q12 of human chromosome 22, is involved in a wide variety of human solid tumors including Ewing sarcoma, related primitive neuroectodermal tumors, malignant melanoma of soft parts and desmoplastic small round cell tumors. In these tumors, the EWS is fused to genes encoding transcriptional activators/repressors, like Fli-1 or erg or ATF 1 or wt1. To better understand the function of the EWS protein, we cloned the EWS cDNA. Sequence analysis of this cDNA revealed differential splicing involving two exons encoding 72 amino acids. Both alternatively spliced transcripts, EWS and EWS-b, are expressed in a variety of cells. Because EWS proteins contain putative conserved RNA binding motifs, we studied the RNA binding properties of the EWS protein. The EWS-b protein binds to RNA in vitro and, specifically, to poly G and poly U. The RNA binding activity was localized to the carboxy terminal 86 amino acids, which constitute RGG box. Thus the amino terminal domain of EWS (NTD-EWS), which is involved in chromosome translocation may regulate the specificity of RNA binding activity of EWS. An EWS-erg chimeric protein, which is found in Ewing's sarcoma cells, functions as a transcriptional activator. Mutational analysis of EWS-erg chimeric protein revealed that NTD-EWS functions as a regulatory domain for the transcriptional activation properties of EWS-erg chimeric protein.
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Affiliation(s)
- T Ohno
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, PA 19107-5541
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29
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Rao VN, Reddy ES. elk-1 proteins interact with MAP kinases. Oncogene 1994; 9:1855-60. [PMID: 8208531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Mitogen activated protein kinases (MAP) or extracellular signal regulated protein kinases (ERK) are a family of protein serine/threonine kinases that are activated very rapidly in response to many extracellular stimuli. elk-1, an ets related gene codes for two transcriptional factors elk-1, which regulates c-fos transcription and delta elk-1, both of which are substrates for MAP kinases. A part of the C-terminal transcriptional activation domain (ETA-2) which is common to both the proteins was previously shown to function as an activator of MAP kinases. In this report, in an attempt to investigate the mechanism of activation of MAP kinases, purified preparations of recombinant elk-1 and P44mpk/ERK-1/ERK-2 proteins were used to show the association of elk-1 proteins with MAP kinases. The specific interactions of elk-1 proteins with MAP kinases were confirmed by co-immunoprecipitation studies. Thus elk-1 proteins appear to regulate the activity of MAP kinases by interacting with them ensuring a conformational change and stimulating their autophosphorylation and activation property. The activation was dependent on the presence of ATP and Mg2+. In vitro phosphorylation of elk-1 protein was not regulatory for autonomous DNA binding activity of elk-1 protein. Cells which were exposed to EGF showed a rapid stimulation of an elk-1 specific kinase activity, probably MAP kinase which phosphorylated MBP and was found to be associated with immobilized GST-elk-1. Furthermore, dephosphorylation studies indicate that elk-1 proteins can activate only tyrosine phosphorylated MAP kinase. These results demonstrate the presence of an alternative pathway/mechanism (other than MAP kinase kinase, MAPKK/Mek) for the activation of MAP kinases with tyrosine phosphorylation occurring before serine/threonine autophosphorylation and activation by elk-1 proteins.
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Affiliation(s)
- V N Rao
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107-5541
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Prasad DD, Rao VN, Lee L, Reddy ES. Differentially spliced erg-3 product functions as a transcriptional activator. Oncogene 1994; 9:669-73. [PMID: 8290279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
ets oncogene superfamily consists of a family of transcriptional factors that functions as activators and/or repressors. Previously, we have identified a member of this ets superfamily namely erg, ets related gene. erg gene was shown to code for at least two proteins erg-1 and erg-2 because of alternative splicing and alternative usage of initiation codon. In this report we show that erg gene codes for an additional erg variant protein, erg-3 as a result of differential splicing which results in the insertion of 24 amino acids in the coding region of erg-2 protein. RNAase protection analysis revealed that erg-3 transcripts are expressed in a variety of cells. Erg-3 was also found to activate the transcription of the reporter TK-CAT gene linked to erg target sequences suggesting that erg-3 codes for a sequence specific transcriptional activator.
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Affiliation(s)
- D D Prasad
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107
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Ohno T, Rao VN, Reddy ES. EWS/Fli-1 chimeric protein is a transcriptional activator. Cancer Res 1993; 53:5859-63. [PMID: 7503813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Fli-1, an ets related gene, was found to be rearranged in 75% of erythroleukemias induced by Friend murine leukemia virus. We have shown previously that the Fli-1 gene codes for a sequence specific transcriptional activator which contains two autonomous transcriptional activation domains, one at the amino terminal region and the other at the carboxy terminal region. Recently human Fli-1 gene was shown to be involved in Ewing's sarcoma and related subtypes of primitive neuroectodermal tumors which share t(11;22) (q24;q12) chromosome translocation. In these tumors the carboxyl terminal region of Fli-1 was found to be fused with the amino terminal region of a putative RNA binding protein, EWS. Because part of the amino terminal transcriptional activation domain of Fli-1 was replaced with the amino terminal domain of the EWS (NTD-EWS) which shares homology with RNA polymerase II, it was speculated that NTD-EWS may interfere with RNA pol II function. Alternatively, NTD-EWS could also contribute to the transcriptional activation function of EWS/Fli-1 chimeric protein by providing either a modulatory/regulatory domain or a novel transcriptional activation domain. Here we show that EWS/Fli-1 chimeric protein functions as a transcriptional activator. Deletion analysis reveals that the EWS domain functions as a modulatory/regulatory domain for the transcriptional activation properties of the carboxy terminal transcriptional activation domain of EWS/Fli-1. We therefore propose that replacement of the amino terminal transcriptional activation domain of the Fli-1 protein with the regulatory domain of NTD-EWS results in the activation of the carboxy terminal transcriptional activation domain of Fli-1 which may be the molecular mechanism involved in these human tumors.
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Affiliation(s)
- T Ohno
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107-5541
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Bhattacharya G, Lee L, Reddy ES, Rao VN. Transcriptional activation domains of elk-1, delta elk-1 and SAP-1 proteins. Oncogene 1993; 8:3459-64. [PMID: 8247551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
elk-1, an ets related gene codes for a sequence specific DNA binding transcriptional activator which in association with serum response factor (SRF) forms a ternary complex at the c-fos serum response element (SRE). Recently the C-terminal region of both elk-1 and delta elk-1 proteins was shown to undergo phosphorylation by MAP kinases and function as an activator of MAP kinases. Here we show that delta elk-1 and two other elk-1 related proteins SAP-1a and SAP-1b, like elk-1, can function as transcriptional activators. In this report we have localized the transcriptional activation domain of the SAP-1 proteins (STA) to a large portion of the carboxy terminal region and have identified two autonomous transcriptional activation domains in the elk-1 protein, one at the amino (ETA-1) and the other at the carboxy terminal region (ETA-2). delta elk-1 protein contains only the ETA-2 domain indicating differential usage of activation domains as a result of alternative splicing. We can speculate that the ETA-1 domain can function in vivo independent of ETA-2, but the ETA-2 domain can function either in the absence of ETA-1 (as seen in delta elk-1) or in the presence of accessory proteins like SRF. The role of SRF in the activation of the ternary complex might be to bind to the ETA-1 domain, somehow conceal it's activation domain and in the process unmask the ETA-2 domain (for phosphorylation by MAP kinases) and activate transcription. The ETA-1 domain may be functioning as a negative regulatory transcriptional activation domain for ETA-2. These observations suggest that the elk-1 family of proteins may not only regulate fos and MAP kinases but also other elk-1 target genes that are essential for cellular growth control.
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Rao VN, Ohno T, Prasad DD, Bhattacharya G, Reddy ES. Analysis of the DNA-binding and transcriptional activation functions of human Fli-1 protein. Oncogene 1993; 8:2167-73. [PMID: 8336942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Three of the ets oncogene superfamily members v-ets, Spi-1/PU.1 and Fli-1, have been shown to be directly involved in retroviral-mediated acute erythroleukemias. The Fli-1 gene was found to be rearranged in 75% of the erythroleukemias induced by Friend murine leukemia virus (F-MuLV), suggesting that it could play a key role in cellular transformation. We have previously isolated and characterized the human Fli-1 gene and have found it to be highly homologous (80%) to the human erg-2 gene. Human Fli-1 was also shown to be rearranged in Ewing's sarcoma cases, in which the amino-terminal region of the Fli-1 gene was replaced with a novel coding region of a putative RNA-binding protein, EWS. In this report, we show that the recombinant Fli-1 protein expressed in bacteria binds to DNA in a sequence-specific manner. It appears that Fli-1 and erg proteins fall into the category of ets proteins that recognize limited ets target sequences, unlike c-ets-1, ets-2 and Elk-1. The Fli-1 gene was found to activate the transcription of the reporter gene that was linked to Fli-1 target sequences, suggesting that Fli-1 is a sequence-specific transcriptional activator. Deletion analysis revealed the presence of two autonomous transcriptional activation domains, one at the amino-terminal region (amino-terminal transcriptional activation domain, ATA) and the other at the carboxy-terminal region (carboxy-terminal transcriptional activation domain, CTA). Secondary structural analysis of ATA and CTA domains revealed the presence of helix-loop-helix (H-L-H) and/or turn-loop-turn (T-L-T) regions. From these results it appears that a portion of the Fli-1 ATA domain (H-L-H region) was replaced by the amino-terminal domain of EWS gene in Ewing's sarcoma cases. Therefore alteration in the transcriptional activation function of Fli-1 may be responsible for human malignancies such as sarcomas, leukemias and lymphomas in which this gene is rearranged.
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Affiliation(s)
- V N Rao
- Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107
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34
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Rao VN, Reddy ES. Elk-1 proteins are phosphoproteins and activators of mitogen-activated protein kinase. Cancer Res 1993; 53:3449-54. [PMID: 8339245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Mitogen-activated protein kinases (MAP kinases) or meiosis-activated myelin basic protein kinase (p44mpk) are known to be activated by a mechanism involving dual phosphorylation at both tyrosine and serine/threonine in response to many extracellular stimuli. There has been considerable speculation as to whether MAP kinases are autophosphorylated and activated by an upstream protein kinase (MAP kinase kinase) or an activator of autophosphorylation or both. Here we report that the ets-related proteins elk-1 and delta elk-1 to be potential physiological substrates and activators of MAP kinases. Our results demonstrate for the first time that MAP kinase activators can also be non-kinase proteins that enhance the autophosphorylation and activation of MAP kinase. These findings could establish a general mechanism wherein specific MAP kinase activator protein(s) may function by interacting with MAP kinases ensuring a conformational change and stimulating their autophosphorylation and activation property. Our results also suggest that the amino-terminal truncated elk-1 proteins are better activators of MAP kinase than full length proteins indicating the presence of a potential negative regulatory region which may control the kinase activator function of elk-1 proteins. Our results suggest differential regulation of elk-1 and delta elk-1 proteins in fibroblasts stimulated by epidermal growth factor implicating a key role for these proteins in the signal transduction pathway. These results establish the presence of an alternative pathway for activation of MAP kinases. Thus we propose that elk-1 proteins may represent key intermediates which would transmit signals arriving at the surface of the cell from activated receptors to downstream MAP kinases in the cytoplasm to reach the transcriptional factors in the nucleus.
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Affiliation(s)
- V N Rao
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107-5541
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35
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Siddique HR, Rao VN, Lee L, Reddy ES. Characterization of the DNA binding and transcriptional activation domains of the erg protein. Oncogene 1993; 8:1751-5. [PMID: 8510921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
erg, an ets related gene encodes a sequence specific DNA binding transcriptional activator protein. We have identified four functional domains of erg protein that are responsible for DNA binding, transcriptional activation and negative regulation of transcriptional activation. Deletion analysis revealed that the 3'-ets domain of the erg protein is sufficient for DNA binding activity. Analysis of these deletion mutants also revealed the presence of two autonomous transcriptional activation domains, one at the amino and the other at the carboxyterminal region. This aminoterminal transcriptional activator domain (5'-ets domain) is conserved in six of the ets genes suggesting that it (ETA, ets Transcriptional Activation domain) may contribute to a common function among these genes. The transcriptional activation function of the carboxy terminal transcriptional activation domain (CTA) was inhibited by the presence of a Negative Regulatory Transcriptional activation domain (NRT), which is located at the amino terminal region of erg DNA binding domain. These results may help in understanding the structure/function relationship of other erg/ets related proteins.
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Affiliation(s)
- H R Siddique
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107-5541
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Rao VN, Reddy ES. Delta elk-1, a variant of elk-1, fails to interact with the serum response factor and binds to DNA with modulated specificity. Cancer Res 1993; 53:215-20. [PMID: 8417810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The ets oncogene superfamily codes for a family of transcriptional factors that are involved in gene regulation not only by autonomous DNA binding but also by indirect DNA binding through interaction with cellular factors. We have previously shown that a member of this superfamily, elk-1, is a sequence specific transcriptional activator, which forms a serum response factor (SRF) dependent ternary complex with serum response element (SRE) similar to p62TCF. We describe here an alternatively spliced variant of elk-1 named delta elk-1, which has lost the SRF interaction domain, negative regulatory DNA binding domain, and part of the elk-1 DNA binding domain. This variant elk-1 protein has lost the capacity to form a SRF dependent ternary complex with SRE and to activate fos transcription. Since this splice variant lacks part of the ets DNA binding domain, it binds to DNA with a specificity that is different from that of the full length elk-1 protein. Therefore differential splicing within the DNA binding and protein-protein interaction domains of transcriptional factors can generate proteins with modulated DNA binding specificities and transcriptional regulation. Thus it is conceivable that variant elk-1 might function by competing for some of the elk-1 target sequences (like SRE) and thereby block the transcriptional activation of fos by SRF and elk-1. Alternately, variant elk-1 protein may be the repressor, recruited by the SRE bound SRF for c-fos repression, or it may have an altogether different function. Therefore, elk-1 appears to fall in the category of genes that encode activators and repressors through the mechanism of differential splicing.
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Affiliation(s)
- V N Rao
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107-5541
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Rao VN, Reddy ES. elk-1 domains responsible for autonomous DNA binding, SRE:SRF interaction and negative regulation of DNA binding. Oncogene 1992; 7:2335-40. [PMID: 1437156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The ets oncogene superfamily consists of a family of sequence-specific DNA-binding transcriptional activator proteins. We have previously identified, cloned and characterized one of the divergent ets-related members elk-1 and shown that it codes for a sequence-specific DNA-binding transcriptional activator. We have also shown that elk-1 forms SRF (Serum Response Factor) dependent ternary complex with SRE (Serum Response Element), similar to p62TCF. In this report, we have mapped the DNA-binding domain of the elk-1 protein (EDB, elk-1 DNA Binding domain) to the 76 amino acid ets homology region. We have also mapped the SRF interaction domain of the elk-1 protein (ESI, elk-1 SRF Interaction domain) to the carboxy-terminal region of the EDB domain. Ternary complex formation by elk-1 requires both EDB and ESI domains of the elk-1 protein. Our results also show that the EDB domain of the elk-1 protein (residues 1-89) binds SRE autonomously, unlike full-length elk-1 protein, suggesting the presence of a potential Negative Regulatory DNA binding domain (NRD) which prevents the binding of elk-1 protein to SRE. Interaction of SRF with the ESI domain allows the elk-1 protein to bind to SRE. Thus elk-1 belongs to a class of transcriptional factors that are involved in gene regulation not only by autonomous DNA binding but also by indirect DNA binding through recruitment by cellular factors.
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Affiliation(s)
- V N Rao
- Jefferson Cancer Institute, Philadelphia, PA 19107
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38
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Prasad DD, Rao VN, Reddy ES. Structure and expression of human Fli-1 gene. Cancer Res 1992; 52:5833-7. [PMID: 1394211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Three ets family members, v-ets, spleen focus forming virus proviral integration 1/Pu.1, and Friend leukemia integration 1 (Fli-1), were shown to be involved in retroviral mediated acute leukemias suggesting that ets family members play a crucial role in transformation. Mouse Fli-1 was shown to be involved in 75% erythroleukemias induced by Friend murine leukemia virus suggesting the possibility that Fli-1 may play a critical role in cellular transformation. Since Fli-1 maps to the mouse chromosome region syntenic with human chromosome 11q23-24, it is tempting to speculate that human Fli-1 may be involved in human sarcomas, leukemias, and lymphomas involving human chromosome 11q23-24. We have isolated complementary DNA clones representing the human homologue of Fli-1 gene. Nucleotide sequence analysis revealed that the human Fli-1 gene codes for a 452-residue protein the predicted amino sequence of which shows 80% homology to the human erg-2 protein previously described. A 3.5-kilobase transcript of the human Fli-1 gene was observed in different cells. Sequence analysis revealed two domains of ets homology, one at the 5' and the other at the 3' end of the Fli-1 gene. This 3'-ets homology domain, which is mainly responsible for DNA binding activity, is seen in all the ets family members; however, the 5'-ets homology region is conserved in only five genes, Fli-1, c-ets-1, ets-2, GABP-alpha, and erg, suggesting a common biological function which is shared among these genes. Interestingly, mouse and human Fli-1 transcripts contain highly homologous 5'-untranslated region suggesting that this conserved region may play an important role in the posttranscriptional regulation of the Fli-1 transcript.
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Affiliation(s)
- D D Prasad
- Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania 19107-5541
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Dudek H, Tantravahi RV, Rao VN, Reddy ES, Reddy EP. Myb and Ets proteins cooperate in transcriptional activation of the mim-1 promoter. Proc Natl Acad Sci U S A 1992; 89:1291-5. [PMID: 1741383 PMCID: PMC48435 DOI: 10.1073/pnas.89.4.1291] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In the generation of the acutely transforming avian retrovirus E26, both myb and ets genes have been transduced, leading to the production of a Gag-Myb-Ets fusion protein. This co-occurrence of v-myb and v-ets oncogenes suggests that the two might have a functional relationship. To look for such a relationship, we tested the transcriptional activation activity of Myb alone or with coexpressed Ets-1 or Ets-2. Using the promoter of the v-Myb-inducible mim-1 gene as a target, we found that full-length c-Myb gene products were poor activators of transcription, while an oncogenic (truncated) form of this protein was a strong trans-activator. However, coexpression of Ets-2 with full-length or truncated forms of Myb greatly increased trans-activation. Coexpression of Ets-1, Fos, Jun, or Myc with Myb did not increase trans-activation of the mim-1 promoter. The ability of Myb and Ets-2 to transactivate was cooperative, since Ets-2 alone gave little or no activation. Bacterially synthesized Ets-2 protein was found to bind specifically to the mim-1 promoter, suggesting that it may be a target for both Myb and Ets proteins. Thus, Myb and Ets proteins can cooperate in transcriptional activation, and their co-occurrence in the E26 virus may reflect a functional relationship between these two oncoproteins. Truncated forms of Myb may have a reduced need for cooperating factors such as Ets-2, and this might constitute an important mechanism associated with oncogenic activation.
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Affiliation(s)
- H Dudek
- Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104
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40
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Rao VN, Reddy ES. A divergent ets-related protein, elk-1, recognizes similar c-ets-1 proto-oncogene target sequences and acts as a transcriptional activator. Oncogene 1992; 7:65-70. [PMID: 1741166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The ets oncogene superfamily consists of a family of sequence-specific DNA-binding proteins that activate transcription. We have previously identified two new members of the ets oncogene superfamily, namely elk-1 and elk-2. In this report we show that the recombinant elk-1 protein expressed in bacteria, like the c-ets-1 proto-oncogene, binds in a sequence-specific manner to Moloney murine sarcoma virus long terminal repeat, E74 target sequences and the PEA3 motif (polyoma enhancer), but does not bind to PU box sequences. Thus analysis of the DNA-binding specificity of ets-related proteins supports the view that different members show similar DNA-binding specificity, which is a general feature of the homeobox proteins. Our data using the chloramphenicol acetyltransferase gene linked to a thymidine kinase promoter containing multimers of the elk-1 target sequence indicates that elk-1 functions as a transcriptional activator. Interestingly, although elk-1 is the most divergent of all the members of the ets gene family, it shows very close similarities with c-ets-1 in some of its sequence-specific DNA-binding specificities. Here, we propose a new function for the elk-1 gene to act as a transcriptional activator of retroviruses and DNA tumor viruses.
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Affiliation(s)
- V N Rao
- Fels Institute for Cancer Research and Molecular Biology, Temple University, Philadelphia, Pennsylvania 19140
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41
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Abstract
A key event in the response of cells to proliferative signals is the rapid, transient induction of the c-fos proto-oncogene, which is mediated through the serum response element (SRE) in the fos promoter. Genomic footprinting and transfection experiments suggest that this activation occurs through a ternary complex that includes the serum response factor (SRF) and the ternary complex factor p62. Interaction of p62TCF with the SRF-SRE binary complex requires a CAGGA tract immediately upstream of the SRE. Proteins of the ets proto-oncogene family bind to similar sequences and we have found that a member of this family, Elk-1, forms SRF-dependent ternary complexes with the SRE. Elk-1 and p62TCF have the same DNA sequence requirements and antibodies against Elk-1 block the binding of both proteins. Furthermore, we show that like p62TCF, Elk-1 forms complexes with the yeast SRF-homologue MCM1 but not with yeast ARG80. But ARG80 mutants that convey interaction with p62TCF can also form complexes with Elk-1. The similarity, or even identity, between Elk-1 and p62TCF suggests a novel regulatory role for Ets proteins that is effected through interaction with other proteins, such as SRF. Furthermore, the possible involvement of an Ets protein in the control of c-fos has interesting implications for proto-oncogene cooperation in cellular growth control.
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Affiliation(s)
- R A Hipskind
- Hannover Medical School, Institute for Molecular Biology, Germany
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42
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Reddy ES, Rao VN. erg, an ets-related gene, codes for sequence-specific transcriptional activators. Oncogene 1991; 6:2285-9. [PMID: 1766675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
E26 is a replication-defective avian acute leukemia virus which causes erythroblastosis and myeloblastosis in chickens. It carries two distinct oncogenes, v-myb and v-ets, both of which contribute to its transforming properties. Several genes related to the ets oncogene (c-ets-1, ets-2, erg, elk-1, elk-2, PU.1/Spi-1, E74 and Fli-1) have been described. Previously we have shown that the erg gene (ets-related gene) codes for at least two proteins (erg-1 and erg-2) because of alternative splicing and alternative usage of the initiation codon. We have expressed erg-1 and erg-2 proteins in Escherichia coli and have used these recombinant proteins to show that they bind to DNA in a sequence-specific manner. erg proteins exhibited different sequence specificity and affinity for the oligonucleotides recognized by c-ets-1, ets-2, some of PU.1/Spi-1 and elk-1, suggesting that the DNA-binding specificities of erg and other members may overlap but are not necessarily identical. The erg gene was found to transactivate a reporter gene that was linked to erg target sequences. These results suggest that erg-1 and erg-2 are sequence-specific transcriptional activators like the other members of the ets oncogene superfamily which represent a distinct class of transcriptional activators.
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Affiliation(s)
- E S Reddy
- Fels Institute for Cancer Research and Molecular Biology, Temple University, Philadelphia, Pennsylvania 19140
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43
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Reddy ES, Rao VN. Localization and modulation of the DNA-binding activity of the human c-ets-1 protooncogene. Cancer Res 1990; 50:5013-6. [PMID: 2165853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The avian acute leukemia virus (E26) induces a mixed erythroid-myeloid leukemia in chickens and carries two distinct oncogenes, v-myb and v-ets. The viral protein responsible for transformation is a gag-myb-ets fusion protein that is located in the nucleus of the transformed cells. The cellular homologue of v-ets (c-ets-1) is highly expressed in lymphoid cells and differs from the v-ets gene at its carboxy terminal region. Here, we show that both the c-ets-1 and v-ets gene products are DNA-binding proteins and their DNA-binding activity is located in the carboxy terminal (46 amino acid residues) region. It appears that this DNA-binding activity is modulated by the extreme carboxy terminal region. The amino acid sequences of the putative ets DNA-binding domain at its carboxy terminal region showed a helix-turn-helix secondary structure. Exchanging the nonhomologous extreme carboxy terminal regions of c-ets-1 with v-ets gene sequences showed differences in DNA-binding affinity, indicating that these differences may be partly responsible for the activation of the ets oncogene.
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Affiliation(s)
- E S Reddy
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
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44
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Rao VN, Huebner K, Isobe M, ar-Rushdi A, Croce CM, Reddy ES. elk, tissue-specific ets-related genes on chromosomes X and 14 near translocation breakpoints. Science 1989; 244:66-70. [PMID: 2539641 DOI: 10.1126/science.2539641] [Citation(s) in RCA: 208] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The myb-ets-containing acute leukemia virus, E26, transforms myeloblasts and erythroblasts in culture and causes a mixed erythroid and myeloid leukemia in chicks. Genes (ets-1, ets-2, and erg) with variable relatedness to the v-ets oncogene of the E26 virus have been identified, cloned, and characterized in several species. Two new members (elk-1 and elk-2) of the ets oncogene superfamily have now been identified. Nucleotide sequence analysis of the elk-1 cDNA clone revealed that this gene encodes a 428-residue protein whose predicted amino acid sequence showed 82% similarity to the 3' region of v-ets. The elk or related sequences appear to be transcriptionally active in testis and lung. The elk cDNA probe detects two loci in the human genome, elk-1 and elk-2, which map to chromosome regions Xp11.2 and 14q32.3, respectively. These loci are near the translocation breakpoint seen in the t(X;18) (p11.2;q11.2), which is characteristic of synovial sarcoma, and the chromosome 14q32 breakpoints seen in ataxia telangiectasia and other T cell malignancies. This suggests the possibility that rearrangements of elk loci may be involved in pathogenesis of certain tumors.
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Affiliation(s)
- V N Rao
- Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104
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Rao VN, Modi WS, Drabkin HD, Patterson D, O'Brien SJ, Papas TS, Reddy ES. The human erg gene maps to chromosome 21, band q22: relationship to the 8; 21 translocation of acute myelogenous leukemia. Oncogene 1988; 3:497-500. [PMID: 3274086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
There is accumulating evidence to support that genes on chromosome 21 play an important role in the development of pathologies associated with leukemia, Down's syndrome, and Alzheimer's disease. We have previously described erg, a human gene related to the ets oncogene. In this study, we have regionally assigned the erg gene to chromosome 21q22.3 by using somatic cell hybrids and in situ hybridization analysis. In light of this chromosome assignment, the relationship of erg to the 21q translocation breakpoint characteristic of acute myelogenous leukemia (AML) was considered. By using a DNA probe that is specific for the erg gene, a panel of rodent-human cell hybrids was analyzed by the Southern technique to study specific chromosome translocations occurring in acute myeloblastic leukemia. The erg gene was found to translocate from chromosome 21 to 8 in the t(8; 21) (q22; q22), a non-random translocation found in patients with acute myelogenous leukemia of the subgroup M2 (AML-M2). The localization of the erg gene to chromosome 21q22 raises the possibility that this gene may be involved in the pathogenesis of AML-M2.
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Affiliation(s)
- V N Rao
- Laboratory of Molecular Oncology, National Cancer Institute, Frederick, Maryland 21701-1013
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46
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Abstract
We have isolated a cDNA clone representing the complete coding sequence of a human gene named erg, related to the ets oncogene. Nucleotide sequence analysis of this cDNA (4.6 kilobases long) revealed that this gene encodes a 363-residue protein whose predicted amino acid sequence showed a homology of approximately equal to 40% and approximately equal to 70% to two domains corresponding to the 5' and 3' regions of v-ets oncogene, respectively. A 3.2- to 3.6-kilobase and approximately equal to 5-kilobase transcript of the erg gene, which differ in size from those of the previously described Hu-ets 1 and Hu-ets 2 genes, were observed in different cells. These results suggest that the erg gene is a member of the ets oncogene family.
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47
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Abstract
The avian acute leukemia virus E26 induces a mixed erythroid-myeloid leukemia in chickens and carries two distinct oncogenes, v-myb and v-ets. Recently, a novel gene named erg, closely related to the v-ets oncogene, was identified in human COLO 320 cells and the nucleotide sequence of its approximately 5.0-kilobase transcript, erg 1 was determined. In the present study, the nucleotide sequence of the alternatively spliced transcript, erg 2, was found to differ from erg 1 by a splicing event that causes a coding frameshift near the amino terminus, resulting in an additional 99-amino acid insertion at the amino-terminus. Expression of complementary DNAs for the two transcripts in vitro resulted in synthesis of polypeptides of approximately 41 and 52 kilodaltons, suggesting the use of alternative translation initiation codons in the case of erg proteins. The erg gene was localized by somatic cell genetic analysis to human chromosome 21. It is proposed that alternative sites of splicing and polyadenylation, together with alternative sites of translation initiation, allow the synthesis of two related polypeptides from a single erg gene transcriptional unit.
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Abstract
A cDNA library was constructed from mouse L cells that were transfected with a human HLA-B7 gene fragment lacking the 5'-segment of exon 2 and all upstream sequences. A cDNA clone (pESP-C103) which is of mouse origin was detected by hybridization with the HLA-B7 gene. Comparison of the amino acid (aa) sequence predicted from the nucleotide sequence of the cDNA and the partial aa sequence of the H-2Kk antigen suggests that this cDNA (pESP-C103) codes for the H-2Kk antigen. This cDNA clone extends to the middle of the leader sequence. Comparison of the nucleotide and deduced aa sequences with those of other H-2 genes revealed an alternative splicing in exon 8 in the case of the H-2Kk gene.
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Yoshie O, Schmidt H, Lengyel P, Reddy ES, Morgan WR, Weissman SM. Transcripts of human HLA gene fragments lacking the 5'-terminal region in transfected mouse cells. Proc Natl Acad Sci U S A 1984; 81:649-53. [PMID: 6322158 PMCID: PMC344892 DOI: 10.1073/pnas.81.3.649] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Clones of mouse L cells transfected with a human HLA-B7 gene fragment lacking the 5' segment of exon 2 and all upstream sequences express HLA-specific transcripts of various lengths. These include species that correspond in size to full-length HLA-B7 mRNA. The level of these transcripts is increased in cells treated with interferon. It is probable that the full-length transcripts arise as a result of the linkage of the HLA-B7 gene fragments with DNA segments providing transcription initiation or polyadenylylation signals.
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50
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Abstract
Seminalplasmin, an antimicrobial protein from bovine seminal plasma that has been earlier shown to inhibit transcription in whole cells and by purified RNA polymerase in vitro, but not translation in whole cells, is now shown to inhibit both transcription and translation independently of each other, in a coupled transcription-translation system from E. coli using phi80dphoAlacZ DNA as the template.
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