32 results on '"Aaron G. Schmidt"'
Search Results
2. Carbohydrate fatty acid monosulphate: oil-in-water adjuvant enhances SARS-CoV-2 RBD nanoparticle-induced immunogenicity and protection in mice
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Etsuro Nanishi, Francesco Borriello, Hyuk-Soo Seo, Timothy R. O’Meara, Marisa E. McGrath, Yoshine Saito, Jing Chen, Joann Diray-Arce, Kijun Song, Andrew Z. Xu, Soumik Barman, Manisha Menon, Danica Dong, Timothy M. Caradonna, Jared Feldman, Blake M. Hauser, Aaron G. Schmidt, Lindsey R. Baden, Robert K. Ernst, Carly Dillen, Jingyou Yu, Aiquan Chang, Luuk Hilgers, Peter Paul Platenburg, Sirano Dhe-Paganon, Dan H. Barouch, Al Ozonoff, Ivan Zanoni, Matthew B. Frieman, David J. Dowling, and Ofer Levy
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Pharmacology ,Infectious Diseases ,Immunology ,Pharmacology (medical) - Abstract
Development of SARS-CoV-2 vaccines that protect vulnerable populations is a public health priority. Here, we took a systematic and iterative approach by testing several adjuvants and SARS-CoV-2 antigens to identify a combination that elicits antibodies and protection in young and aged mice. While demonstrating superior immunogenicity to soluble receptor-binding domain (RBD), RBD displayed as a protein nanoparticle (RBD-NP) generated limited antibody responses. Comparison of multiple adjuvants including AddaVax, AddaS03, and AS01B in young and aged mice demonstrated that an oil-in-water emulsion containing carbohydrate fatty acid monosulphate derivative (CMS:O/W) most effectively enhanced RBD-NP-induced cross-neutralizing antibodies and protection across age groups. CMS:O/W enhanced antigen retention in the draining lymph node, induced injection site, and lymph node cytokines, with CMS inducing MyD88-dependent Th1 cytokine polarization. Furthermore, CMS and O/W synergistically induced chemokine production from human PBMCs. Overall, CMS:O/W adjuvant may enhance immunogenicity and protection of vulnerable populations against SARS-CoV-2 and other infectious pathogens.
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- 2023
3. Humoral responses to the SARS-CoV-2 spike and receptor binding domain in context of pre-existing immunity confer broad sarbecovirus neutralization
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Blake M. Hauser, Maya Sangesland, Evan C. Lam, Jared Feldman, Alejandro B. Balazs, Daniel Lingwood, and Aaron G. Schmidt
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Epitopes ,SARS-CoV-2 ,Spike Glycoprotein, Coronavirus ,Immunology ,COVID-19 ,Humans ,Immunology and Allergy ,Antibodies, Viral - Abstract
Since the emergence of SARS-CoV-2 (SARS-2), multiple vaccine candidates were developed and studied both preclinically and clinically. Nearly all are based on the SARS-2 spike glycoprotein or its receptor binding domain (RBD). Studies of these vaccine candidates have largely been in a SARS-2 naïve context. However, pre-existing immunity to SARS-2 acquired through infection or vaccination continues to increase. Evaluating future vaccine candidates in context of this pre-existing immunity is necessary to understand how immune responses are subsequently influenced. Here, we evaluated the serum and IgG+B cell responses to the SARS-2 RBD in context of pre-existing immunity elicited by the full SARS-2 spike, and we compared this to boosting with the full SARS-2 spike. Boosting with the SARS-2 RBD resulted in increased reactivity to RBD epitopes, but both immunization regimens resulted in similarly broad neutralization across diverse sarbecoviruses. These findings may inform comparison among SARS-2 RBD-based vaccine candidates to currently approved spike-based candidates.
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- 2022
4. Rotavirus VP4 Epitope of a Broadly Neutralizing Human Antibody Defined by Its Structure Bound with an Attenuated-Strain Virion
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Simon Jenni, Zongli Li, Yuhuan Wang, Theresa Bessey, Eric N. Salgado, Aaron G. Schmidt, Harry B. Greenberg, Baoming Jiang, and Stephen C. Harrison
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Rotavirus ,Protein Conformation ,Immunology ,Cryoelectron Microscopy ,Virion ,Vaccines, Attenuated ,Microbiology ,Rats ,Immunoglobulin Fab Fragments ,Mice ,Virology ,Insect Science ,Vaccines and Antiviral Agents ,Animals ,Epitopes, B-Lymphocyte ,Humans ,Capsid Proteins ,Serial Passage ,Broadly Neutralizing Antibodies - Abstract
Rotavirus live-attenuated vaccines, both mono- and pentavalent, generate broadly heterotypic protection. B-cells isolated from adults encode neutralizing antibodies, some with affinity for VP5*, that afford broad protection in mice. We have mapped the epitope of one such antibody by determining the high-resolution cryo-EM structure of its antigen-binding fragment (Fab) bound to the virion of a candidate vaccine strain, CDC-9. The Fab contacts both the distal end of a VP5* β-barrel domain and the two VP8* lectin-like domains at the tip of a projecting spike. Its interactions with VP8* do not impinge on the likely receptor-binding site, suggesting that the mechanism of neutralization is at a step subsequent to initial attachment. We also examined structures of CDC-9 virions from two different stages of serial passaging. Nearly all the VP4 (cleaved to VP8*/VP5*) spikes on particles from the earlier passage (wild-type isolate) had transitioned from the “upright” conformation present on fully infectious virions to the “reversed” conformation that is probably the end state of membrane insertion, unable to mediate penetration, consistent with the very low in vitro infectivity of the wild-type isolate. About half the VP4 spikes were upright on particles from the later passage, which had recovered substantial in vitro infectivity but had acquired an attenuated phenotype in neonatal rats. A mutation in VP4 that occurred during passaging appears to stabilize the interface at the apex of the spike and could account for the greater stability of the upright spikes on the late-passage, attenuated isolate. IMPORTANCE Rotavirus live-attenuated vaccines generate broadly heterotypic protection, and B-cells isolated from adults encode antibodies that are broadly protective in mice. Determining the structural and mechanistic basis of broad protection can contribute to understanding the current limitations of vaccine efficacy in developing countries. The structure of an attenuated human rotavirus isolate (CDC-9) bound with the Fab fragment of a broadly heterotypic protective antibody shows that protection is probably due to inhibition of the conformational transition in the viral spike protein (VP4) critical for viral penetration, rather than to inhibition of receptor binding. A comparison of structures of CDC-9 virus particles at two stages of serial passaging supports a proposed mechanism for initial steps in rotavirus membrane penetration.
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- 2022
5. Antibodies from primary humoral responses modulate the recruitment of naive B cells during secondary responses
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Jeroen M.J. Tas, Ja-Hyun Koo, Ying-Cing Lin, Zhenfei Xie, Jon M. Steichen, Abigail M. Jackson, Blake M. Hauser, Xuesong Wang, Christopher A. Cottrell, Jonathan L. Torres, John E. Warner, Kathrin H. Kirsch, Stephanie R. Weldon, Bettina Groschel, Bartek Nogal, Gabriel Ozorowski, Sandhya Bangaru, Nicole Phelps, Yumiko Adachi, Saman Eskandarzadeh, Michael Kubitz, Dennis R. Burton, Daniel Lingwood, Aaron G. Schmidt, Usha Nair, Andrew B. Ward, William R. Schief, and Facundo D. Batista
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B-Lymphocytes ,Epitopes ,Mice ,Infectious Diseases ,Immunology ,Immunology and Allergy ,Animals ,Antigens ,Antibodies, Viral ,Germinal Center ,Antibodies, Neutralizing ,Immunity, Humoral - Abstract
Vaccines generate high-affinity antibodies by recruiting antigen-specific B cells to germinal centers (GCs), but the mechanisms governing the recruitment to GCs on secondary challenges remain unclear. Here, using preclinical SARS-CoV and HIV mouse models, we demonstrated that the antibodies elicited during primary humoral responses shaped the naive B cell recruitment to GCs during secondary exposures. The antibodies from primary responses could either enhance or, conversely, restrict the GC participation of naive B cells: broad-binding, low-affinity, and low-titer antibodies enhanced recruitment, whereas, by contrast, the high titers of high-affinity, mono-epitope-specific antibodies attenuated cognate naive B cell recruitment. Thus, the directionality and intensity of that effect was determined by antibody concentration, affinity, and epitope specificity. Circulating antibodies can, therefore, be important determinants of antigen immunogenicity. Future vaccines may need to overcome-or could, alternatively, leverage-the effects of circulating primary antibodies on subsequent naive B cell recruitment.
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- 2022
6. Ad26 vaccine protects against SARS-CoV-2 severe clinical disease in hamsters
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John S. Burke, Noe B. Mercado, Jingyou Yu, Dan H. Barouch, Komlan Tevi, Vaneesha Ali, Shant H. Mahrokhian, Felix Nampanya, Sarah Ducat, Carly E. Starke, Ramya Nityanandam, Lisa H. Tostanoski, Blake M. Hauser, Linda M. Wrijil, Makda S. Gebre, Kathleen Busman-Sahay, Stephanie Fischinger, Dalia Benetiene, Stephen Bondoc, Maciel Porto, Cesar Piedra-Mora, Chi N. Chan, Jacob D. Estes, Jared Feldman, Frank Wegmann, Hanneke Schuitemaker, Douglas A. Lauffenburger, Mark G. Lewis, Roland Zahn, Gabriel Dagotto, Zijin Lin, Katherine McMahan, Caroline Atyeo, Laurent Pessaint, Timothy M. Caradonna, Galit Alter, Carolin Loos, Michael Nekorchuk, Catherine Jacob-Dolan, Esther A. Bondzie, Jerome Custers, Aaron G. Schmidt, Amanda J. Martinot, and Hanne Leth Andersen
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0301 basic medicine ,Male ,Letter ,COVID-19 Vaccines ,viruses ,Genetic Vectors ,Severity of Illness Index ,General Biochemistry, Genetics and Molecular Biology ,Adenoviridae ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,Cricetinae ,medicine ,Animals ,Humans ,Vector (molecular biology) ,Neutralizing antibody ,skin and connective tissue diseases ,Vaccines ,Vaccines, Synthetic ,biology ,Mesocricetus ,business.industry ,SARS-CoV-2 ,fungi ,virus diseases ,COVID-19 ,General Medicine ,Viral Load ,medicine.disease ,Antibodies, Neutralizing ,respiratory tract diseases ,Pneumonia ,Disease Models, Animal ,030104 developmental biology ,Respiratory failure ,Immunization ,Viral replication ,Immunology ,Spike Glycoprotein, Coronavirus ,biology.protein ,Female ,business ,Viral load ,030217 neurology & neurosurgery - Abstract
Coronavirus disease 2019 (COVID-19) in humans is often a clinically mild illness, but some individuals develop severe pneumonia, respiratory failure and death1–4. Studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in hamsters5–7 and nonhuman primates8–10 have generally reported mild clinical disease, and preclinical SARS-CoV-2 vaccine studies have demonstrated reduction of viral replication in the upper and lower respiratory tracts in nonhuman primates11–13. Here we show that high-dose intranasal SARS-CoV-2 infection in hamsters results in severe clinical disease, including high levels of virus replication in tissues, extensive pneumonia, weight loss and mortality in a subset of animals. A single immunization with an adenovirus serotype 26 vector-based vaccine expressing a stabilized SARS-CoV-2 spike protein elicited binding and neutralizing antibody responses and protected against SARS-CoV-2-induced weight loss, pneumonia and mortality. These data demonstrate vaccine protection against SARS-CoV-2 clinical disease. This model should prove useful for preclinical studies of SARS-CoV-2 vaccines, therapeutics and pathogenesis., A single immunization with an adenovirus vector-based vaccine expressing a stabilized SARS-CoV-2 spike protein induces protection against SARS-CoV-2-induced weight loss, pneumonia and mortality in hamsters.
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- 2020
7. Early cross-coronavirus reactive signatures of humoral immunity against COVID-19
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Patrick Martin, Marcia B. Goldberg, Radosław P. Nowak, Michael R. Filbin, Moshe Sade-Feldman, Maricarmen Rojas-Lopez, Hargun K. Khanna, Chuangqi Wang, Brendan M. Lilley, Brenna N. McKaig, Brian C. Russo, Jaewon Kang, Yannic C. Bartsch, Anna L.K. Gonye, Nir Hacohen, Diana Dayal, Ching-Lin Hsieh, Boris Julg, Jessica Tantivit, Galit Alter, Kendall M. Lavin-Parsons, Stephanie Fischinger, Nicole C. Charland, Carl L. Lodenstein, Eric J. Nilles, Jason S. McLellan, Aaron G. Schmidt, Anil S. Menon, Kathryn Bowman, Justin D. Margolin, Douglas A. Lauffenburger, Jared Feldman, Elon R. Musk, Alexandra-Chloé Villani, Nihaarika Sharma, Thomas J. LaSalle, Eric S. Fischer, Paulina Kaplonek, Kasidet Manakongtreecheep, Matthew J. Gorman, Molly Thomas, and Irena Gushterova
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2019-20 coronavirus outbreak ,Adolescent ,Coronavirus disease 2019 (COVID-19) ,viruses ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Immunology ,Receptors, Fc ,Cross Reactions ,Biology ,medicine.disease_cause ,Article ,Cohort Studies ,Coronavirus OC43, Human ,Young Adult ,Mixed linear model ,medicine ,Humans ,Survivors ,Coronavirus ,SARS-CoV-2 ,Disease progression ,virus diseases ,COVID-19 ,General Medicine ,biochemical phenomena, metabolism, and nutrition ,Immunoglobulin Class Switching ,Virology ,Immunity, Humoral ,Spike Glycoprotein, Coronavirus ,Humoral immunity ,Correlation analysis ,Disease Progression - Abstract
The introduction of vaccines has inspired hope in the battle against SARS-CoV-2. However, the emergence of viral variants, in the absence of potent antivirals, has left the world struggling with the uncertain nature of this disease. Antibodies currently represent the strongest correlate of immunity against SARS-CoV-2, thus we profiled the earliest humoral signatures in a large cohort of acutely ill (survivors and nonsurvivors) and mild or asymptomatic individuals with COVID-19. Although a SARS-CoV-2–specific immune response evolved rapidly in survivors of COVID-19, nonsurvivors exhibited blunted and delayed humoral immune evolution, particularly with respect to S2-specific antibodies. Given the conservation of S2 across β-coronaviruses, we found that the early development of SARS-CoV-2–specific immunity occurred in tandem with preexisting common β-coronavirus OC43 humoral immunity in survivors, which was also selectively expanded in individuals that develop a paucisymptomatic infection. These data point to the importance of cross-coronavirus immunity as a correlate of protection against COVID-19.
- Published
- 2021
8. An adjuvanted SARS-CoV-2 RBD nanoparticle elicits neutralizing antibodies and fully protective immunity in aged mice
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Timothy R O'Meara, Jing Chen, Blake M. Hauser, Marisa McGrath, Aaron G. Schmidt, Yoshine Saito, Jingyou Yu, Dan H. Barouch, Jared Feldman, Peter Paul L.I. Platenburg, Carly Dillen, Robert Haupt, Luuk A. Th. Hilgers, Kijun Song, Joann Diray-Arce, Etsuro Nanishi, Francesco Borriello, Ivan Zanoni, Aiquan Chang, David J. Dowling, Stuart Weston, Timothy M. Caradonna, Robert M. Johnson, Holly L. Hammond, Al Ozonoff, Andrew Z Xu, Ofer Levy, Hyuk-Soo Seo, Robert K. Ernst, Matthew B. Frieman, and Sirano Dhe-Paganon
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chemistry.chemical_classification ,Chemokine ,biology ,business.industry ,Protein subunit ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Fatty acid ,medicine.anatomical_structure ,chemistry ,Antigen ,Immunology ,biology.protein ,Medicine ,Antibody ,business ,Lymph node ,Gene - Abstract
SUMMARYDevelopment of affordable and effective vaccines that can also protect vulnerable populations such as the elderly from COVID-19-related morbidity and mortality is a public health priority. Here we took a systematic and iterative approach by testing several SARS-CoV-2 protein antigens and adjuvants to identify a combination that elicits neutralizing antibodies and protection in young and aged mice. In particular, SARS-CoV-2 receptorbinding domain (RBD) displayed as a protein nanoparticle (RBD-NP) was a highly effective antigen, and when formulated with an oil-in-water emulsion containing Carbohydrate fatty acid MonoSulphate derivative (CMS) induced the highest levels of cross-neutralizing antibodies compared to other oil-in-water emulsions or AS01B. Mechanistically, CMS induced antigen retention in the draining lymph node (dLN) and expression of cytokines, chemokines and type I interferon-stimulated genes at both injection site and dLN. Overall, CMS:RBD-NP is effective across multiple age groups and is an exemplar of a SARS-CoV-2 subunit vaccine tailored to the elderly.
- Published
- 2021
9. Altering the Immunogenicity of Hemagglutinin Immunogens by Hyperglycosylation and Disulfide Stabilization
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Dana N. Thornlow, Andrew N. Macintyre, Thomas H. Oguin, Amelia B. Karlsson, Erica L. Stover, Heather E. Lynch, Gregory D. Sempowski, and Aaron G. Schmidt
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immunogen design ,Glycan ,Glycosylation ,Immunogen ,Immunology ,Hemagglutinin (influenza) ,Hemagglutinin Glycoproteins, Influenza Virus ,Immunodominance ,Protein Engineering ,Epitope ,chemistry.chemical_compound ,Immunogenicity, Vaccine ,Immunology and Allergy ,Animals ,Humans ,Cysteine ,hemagglutinin ,Original Research ,chemistry.chemical_classification ,B cells ,biology ,Chemistry ,Immunodominant Epitopes ,Immunogenicity ,adaptive immunity ,RC581-607 ,Antibodies, Neutralizing ,Cell biology ,Immunity, Humoral ,Mice, Inbred C57BL ,HEK293 Cells ,Influenza Vaccines ,biology.protein ,glycans ,Female ,Immunization ,Immunologic diseases. Allergy ,Glycoprotein ,influenza - Abstract
Influenza virus alters glycosylation patterns on its surface exposed glycoproteins to evade host adaptive immune responses. The viral hemagglutinin (HA), in particular the H3 subtype, has increased its overall surface glycosylation since its introduction in 1968. We previously showed that modulating predicted N-linked glycosylation sites on H3 A/Hong Kong/1/1968 HA identified a conserved epitope at the HA interface. This epitope is occluded on the native HA trimer but is likely exposed during HA “breathing” on the virion surface. Antibodies directed to this site are protective via an ADCC-mediated mechanism. This glycan engineering strategy made an otherwise subdominant epitope dominant in the murine model. Here, we asked whether cysteine stabilization of the hyperglycosylated HA trimer could reverse this immunodominance by preventing access to the interface epitope and focus responses to the HA receptor binding site (RBS). While analysis of serum responses from immunized mice did not show a redirection to the RBS, cysteine stabilization did result in an overall reduction in immunogenicity of the interface epitope. Thus, glycan engineering and cysteine stabilization are two strategies that can be used together to alter immunodominance patterns to HA. These results add to rational immunogen design approaches used to manipulate immune responses for the development of next-generation influenza vaccines.
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- 2021
10. Early cross-coronavirus reactive signatures of protective humoral immunity against COVID-19
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Galit Alter, Boris Juelg, Patrick H. Martin, Douglas A. Lauffenburger, Aaron G. Schmidt, Yannic C. Bartsch, Radoslow Nowak, Ching-Lin Hsieh, Kathryn Bowman, Marcia B. Goldberg, Jared Feldman, Stephanie Fischinger, Jason S McLellan, Jaewon Kang, Paulina Kaplonek, Chuangqi Wang, Matthew J. Gorman, Nir Hacohen, Michael R. Filbin, Diana Dayal, Elon R. Musk, Anil S. Menon, and Eric S. Fischer
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Coronavirus disease 2019 (COVID-19) ,viruses ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Disease ,biochemical phenomena, metabolism, and nutrition ,Biology ,medicine.disease_cause ,Immune system ,Immunity ,Humoral immunity ,Immunology ,biology.protein ,medicine ,Antibody ,Coronavirus - Abstract
The introduction of vaccines has inspired new hope in the battle against SARS-CoV-2. However, the emergence of viral variants, in the absence of potent antivirals, has left the world struggling with the uncertain nature of this disease. Antibodies currently represent the strongest correlate of immunity against COVID-19, thus we profiled the earliest humoral signatures in a large cohort of severe and asymptomatic COVID-19 individuals. While a SARS-CoV-2-specific immune response evolved rapidly in survivors of COVID-19, non-survivors exhibited blunted and delayed humoral immune evolution, particularly with respect to S2-specific antibody evolution. Given the conservation of S2 across β-coronaviruses, we found the early development of SARS-CoV-2-specific immunity occurred in tandem with pre-existing common β-coronavirus OC43 humoral immunity in survivors, which was selectively also expanded in individuals that develop paucisymptomatic infection. These data point to the importance of cross-coronavirus immunity as a correlate of protection against COVID-19.
- Published
- 2021
11. Alum:CpG adjuvant enables SARS-CoV-2 RBD-induced protection in aged mice and synergistic activation of human elder type 1 immunity
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Etsuro Nanishi, Francesco Borriello, Timothy R. O’Meara, Marisa E. McGrath, Yoshine Saito, Robert E. Haupt, Hyuk-Soo Seo, Simon D. van Haren, Byron Brook, Jing Chen, Joann Diray-Arce, Simon Doss-Gollin, Maria De Leon, Katherine Chew, Manisha Menon, Kijun Song, Andrew Z. Xu, Timothy M. Caradonna, Jared Feldman, Blake M. Hauser, Aaron G. Schmidt, Amy C. Sherman, Lindsey R. Baden, Robert K. Ernst, Carly Dillen, Stuart M. Weston, Robert M. Johnson, Holly L. Hammond, Romana Mayer, Allen Burke, Maria E. Bottazzi, Peter J. Hotez, Ulrich Strych, Aiquan Chang, Jingyou Yu, Dan H. Barouch, Sirano Dhe-Paganon, Ivan Zanoni, Al Ozonoff, Matthew B. Frieman, Ofer Levy, and David J. Dowling
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Chemokine ,COVID-19 Vaccines ,CpG Oligodeoxynucleotide ,Aluminum Hydroxide ,Context (language use) ,Antibodies, Viral ,Article ,Mice ,Animals ,Humans ,Medicine ,Pandemics ,BNT162 Vaccine ,Aged ,Vaccines, Synthetic ,biology ,SARS-CoV-2 ,business.industry ,Immunogenicity ,COVID-19 ,TLR9 ,Antibodies, Neutralizing ,CpG site ,Spike Glycoprotein, Coronavirus ,Immunology ,TLR3 ,biology.protein ,mRNA Vaccines ,Antibody ,business - Abstract
Global deployment of vaccines that can provide protection across several age groups is still urgently needed to end the COVID-19 pandemic especially for low- and middle-income countries. While vaccines against SARS-CoV-2 based on mRNA and adenoviral-vector technologies have been rapidly developed, additional practical and scalable SARS-CoV-2 vaccines are needed to meet global demand. In this context, protein subunit vaccines formulated with appropriate adjuvants represent a promising approach to address this urgent need. Receptor-binding domain (RBD) is a key target of neutralizing antibodies (Abs) but is poorly immunogenic. We therefore compared pattern recognition receptor (PRR) agonists, including those activating STING, TLR3, TLR4 and TLR9, alone or formulated with aluminum hydroxide (AH), and benchmarked them to AS01B and AS03-like emulsion-based adjuvants for their potential to enhance RBD immunogenicity in young and aged mice. We found that the AH and CpG adjuvant formulation (AH:CpG) demonstrated the highest enhancement of anti-RBD neutralizing Ab titers in both age groups (∼80-fold over AH), and protected aged mice from the SARS-CoV-2 challenge. Notably, AH:CpG-adjuvanted RBD vaccine elicited neutralizing Abs against both wild-type SARS-CoV-2 and B.1.351 variant at serum concentrations comparable to those induced by the authorized mRNA BNT162b2 vaccine. AH:CpG induced similar cytokine and chemokine gene enrichment patterns in the draining lymph nodes of both young adult and aged mice and synergistically enhanced cytokine and chemokine production in human young adult and elderly mononuclear cells. These data support further development of AH:CpG-adjuvanted RBD as an affordable vaccine that may be effective across multiple age groups.One Sentence SummaryAlum and CpG enhance SARS-CoV-2 RBD protective immunity, variant neutralization in aged mice and Th1-polarizing cytokine production by human elder leukocytes.
- Published
- 2021
12. Coronavirus-Specific Antibody Cross Reactivity in Rhesus Macaques following SARS-CoV-2 Vaccination and Infection
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Roland Zahn, Katherine McMahan, Catherine Jacob-Dolan, Jingyou Yu, Frank Wegmann, Hanneke Schuitemaker, Dan H. Barouch, Jared Feldman, and Aaron G. Schmidt
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viruses ,Immunology ,coronavirus ,medicine.disease_cause ,Microbiology ,Cross-reactivity ,03 medical and health sciences ,0302 clinical medicine ,Virology ,Vaccines and Antiviral Agents ,medicine ,neutralizing antibodies ,030212 general & internal medicine ,Neutralizing antibody ,skin and connective tissue diseases ,030304 developmental biology ,Coronavirus ,0303 health sciences ,biology ,SARS-CoV-2 ,fungi ,virus diseases ,biology.organism_classification ,respiratory tract diseases ,Vaccination ,body regions ,Immunization ,Polyclonal antibodies ,Insect Science ,Lentivirus ,Humoral immunity ,biology.protein - Abstract
The rapid development and deployment of SARS-CoV-2 vaccines has been unprecedented. In this study, we explore the cross-reactivity of SARS-CoV-2-specific antibody responses to other coronaviruses., Vaccines are being rapidly developed with the goal of ending the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. However, the extent to which SARS-CoV-2 vaccination induces serum responses that cross-react with other coronaviruses remains poorly studied. Here, we define serum profiles in rhesus macaques after vaccination with DNA- or Ad26-based vaccines expressing SARS-CoV-2 spike protein followed by SARS-CoV-2 challenge, or SARS-CoV-2 infection alone. Analysis of serum responses showed robust reactivity to the SARS-CoV-2 full-length spike protein and receptor binding domain (RBD), both included in the vaccine. However, serum cross-reactivity to the closely related sarbecovirus SARS-CoV-1 spike and RBD was reduced. Reactivity was also measured to the distantly related common cold alphacoronavirus (229E and NL63) and betacoronavirus (OC43 and HKU1) spike proteins. Using SARS-CoV-2 and SARS-CoV-1 lentivirus-based pseudoviruses, we show that neutralizing antibody responses were predominantly SARS-CoV-2 specific. These data define patterns of cross-reactive binding and neutralizing serum responses induced by SARS-CoV-2 infection and vaccination in rhesus macaques. Our observations have important implications for understanding polyclonal responses to the SARS-CoV-2 spike protein, which will facilitate future CoV vaccine assessment and development. IMPORTANCE The rapid development and deployment of SARS-CoV-2 vaccines has been unprecedented. In this study, we explore the cross-reactivity of SARS-CoV-2-specific antibody responses to other coronaviruses. By analyzing responses from nonhuman primates (NHPs) both before and after immunization with DNA or Ad26-vectored vaccines, we find patterns of cross-reactivity that mirror those induced by SARS-CoV-2 infection. These data highlight the similarities between infection and vaccine-induced humoral immunity for SARS-CoV-2 and cross-reactivity of these responses to other CoVs.
- Published
- 2021
13. Naive human B cells engage the receptor binding domain of SARS-CoV-2, variants of concern, and related sarbecoviruses
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Aaron G. Schmidt, Larance Ronsard, Maya Sangesland, Clara G. Altomare, Nathania Hartojo, Daniel Lingwood, Vintus Okonkwo, Goran Bajic, Julia Bals, Alejandro B. Balazs, Thalia Bracamonte Moreno, Evan C. Lam, Kerri St. Denis, Jared Feldman, and Blake M. Hauser
- Subjects
2019-20 coronavirus outbreak ,COVID-19 Vaccines ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,coronaviruses ,Immunology ,Naive B cell ,macromolecular substances ,Complementarity determining region ,Biology ,Lymphocyte Activation ,Article ,Germline ,Epitopes ,medicine ,Humans ,Pathogen ,Antigens, Viral ,Gene ,B cell ,B cells ,B-Lymphocytes ,SARS-CoV-2 ,Repertoire ,COVID-19 ,General Medicine ,Acquired immune system ,immunity ,Antibodies, Neutralizing ,Virology ,Coronavirus ,medicine.anatomical_structure ,Spike Glycoprotein, Coronavirus ,biology.protein ,Antibody ,germline precursors - Abstract
Initial exposure to a pathogen elicits an adaptive immune response to control and eradicate the threat. Interrogating the abundance and specificity of the naive B cell repertoire drives understanding of how to mount protective responses. Here, we isolated naive B cells from eight seronegative human donors targeting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (RBD). Single-cell B cell receptor (BCR) sequencing identified diverse gene usage and no restriction on complementarity determining region length. A subset of recombinant antibodies produced by naive B cell precursors bound to SARS-CoV-2 RBD and engaged circulating variants including B.1.1.7, B.1.351, and B.1.617.2, as well as preemergent bat-derived coronaviruses RaTG13, SHC104, and WIV1. By structural characterization of a naive antibody in complex with SARS-CoV-2 spike, we identified a conserved mode of recognition shared with infection-induced antibodies. We found that representative naive antibodies could signal in a B cell activation assay, and by using directed evolution, we could select for a higher-affinity RBD interaction, conferred by a single amino acid change. The minimally mutated, affinity-matured antibodies also potently neutralized SARS-CoV-2. Understanding the SARS-CoV-2 RBD–specific naive repertoire may inform potential responses capable of recognizing future SARS-CoV-2 variants or emerging coronaviruses, enabling the development of pan-coronavirus vaccines aimed at engaging protective germline responses.
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- 2021
14. COVID-19 neutralizing antibodies predict disease severity and survival
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John A. Branda, Jochen K. Lennerz, Alejandro B. Balazs, Blake M. Hauser, Diane Yang, Evan C. Lam, Timothy M. Caradonna, Daniel Lingwood, Michael G Astudillo, Adam Nitido, Tyler E. Miller, A. John Iafrate, Richelle C. Charles, Aaron G. Schmidt, Galit Alter, Mandakolathur R. Murali, Kiera L. Clayton, Anand S. Dighe, Wilfredo F. Garcia-Beltran, and Jared Feldman
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Male ,Comorbidity ,pro-inflammatory cytokines ,Antibodies, Viral ,medicine.disease_cause ,Severity of Illness Index ,Immunoglobulin G ,Neutralization ,RBD ,0302 clinical medicine ,Pandemic ,Medicine ,Coronavirus ,0303 health sciences ,biology ,Middle Aged ,D614G ,Institutional review board ,LYME ,Titer ,Treatment Outcome ,Massachusetts ,Spike Glycoprotein, Coronavirus ,Cytokines ,ELISA ,disease severity ,Female ,medicine.symptom ,Antibody ,Adult ,medicine.medical_specialty ,Enzyme-Linked Immunosorbent Assay ,Cross Reactions ,Asymptomatic ,General Biochemistry, Genetics and Molecular Biology ,Article ,Proinflammatory cytokine ,03 medical and health sciences ,Immune system ,Protein Domains ,WIV1-CoV ,Internal medicine ,Humans ,Potency ,neutralizing antibodies ,030304 developmental biology ,SARS-CoV-2 ,business.industry ,COVID-19 ,spike ,Antibodies, Neutralizing ,Survival Analysis ,Immunoglobulin A ,Immunoglobulin M ,Humoral immunity ,Immunology ,biology.protein ,business ,030217 neurology & neurosurgery ,Biomarkers - Abstract
Coronavirus disease 2019 (COVID-19) exhibits variable symptom severity ranging from asymptomatic to life-threatening, yet the relationship between severity and the humoral immune response is poorly understood. We examined antibody responses in 113 COVID-19 patients and found that severe cases resulting in intubation or death exhibited increased inflammatory markers, lymphopenia, pro-inflammatory cytokines, and high anti-receptor binding domain (RBD) antibody levels. Although anti-RBD immunoglobulin G (IgG) levels generally correlated with neutralization titer, quantitation of neutralization potency revealed that high potency was a predictor of survival. In addition to neutralization of wild-type SARS-CoV-2, patient sera were also able to neutralize the recently emerged SARS-CoV-2 mutant D614G, suggesting cross-protection from reinfection by either strain. However, SARS-CoV-2 sera generally lacked cross-neutralization to a highly homologous pre-emergent bat coronavirus, WIV1-CoV, which has not yet crossed the species barrier. These results highlight the importance of neutralizing humoral immunity on disease progression and the need to develop broadly protective interventions to prevent future coronavirus pandemics., Graphical abstract, Highlights • Severe COVID-19 associates with higher antibody production and neutralization titers • Neutralization potency of anti-RBD antibodies predicts disease severity and survival • Immunomodulatory COVID-19-directed therapies modulate antibody responses • COVID-19 sera neutralize D614 and G614 variants, but not pre-emergent WIV1-CoV, Garcia-Beltran et al. show that the development of more potent neutralizing antibodies during SARS-CoV-2 infection predicts COVID-19 survival. Protective antibody responses exhibit potent neutralization against the currently circulating SARS-CoV-2 D614G spike variant but lack significant activity against pre-emergent WIV1-CoV spike, suggesting that convalescent patients are likely to remain susceptible to future pandemics.
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- 2020
15. Persistence and decay of human antibody responses to the receptor binding domain of SARS-CoV-2 spike protein in COVID-19 patients
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Timothy M. Caradonna, Edward T. Ryan, A. John Iafrate, Rachel Mills, Mohammad Kamruzzaman, Tyler E. Miller, Galit Alter, Damien Slater, Caroline Atyeo, Ariana Nodoushani, Zhenfeng Li, Andrew S. Azman, Stephen B. Calderwood, Forrest K. Jones, Blake M. Hauser, Anita S. Iyer, Erica Teng, Regina C. LaRocque, Jason B. Harris, Elizabeth Oliver, Guillaume Mellon, Stephanie Fischinger, Meagan Kelly, Wilfredo F. Garcia-Beltran, John A. Branda, Richelle C. Charles, Jingyou Yu, Michael G Astudillo, Aaron G. Schmidt, Diane Yang, Stephen A. Lauer, Margaret Becker, Sarah E Turbett, Dan H. Barouch, and Jared Feldman
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0301 basic medicine ,Immunoglobulin A ,Male ,Antibodies, Viral ,Immunoglobulin G ,Cohort Studies ,0302 clinical medicine ,Medicine ,030212 general & internal medicine ,Neutralizing antibody ,skin and connective tissue diseases ,biology ,General Medicine ,Middle Aged ,Isotype ,Titer ,Spike Glycoprotein, Coronavirus ,Female ,Antibody ,Coronavirus Infections ,Adult ,Pneumonia, Viral ,Immunology ,macromolecular substances ,Cross Reactions ,03 medical and health sciences ,Betacoronavirus ,Protein Domains ,Humans ,Seroconversion ,Pandemics ,Aged ,business.industry ,SARS-CoV-2 ,fungi ,COVID-19 ,Antibodies, Neutralizing ,body regions ,Coronavirus ,030104 developmental biology ,Immunoglobulin M ,biology.protein ,Dried Blood Spot Testing ,business ,Biomarkers ,Reports - Abstract
IgM and IgA responses to SARS-CoV-2 RBD in severe COVID patients decay rapidly, while IgG responses persist for over 3 months., We measured plasma and/or serum antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in 343 North American patients infected with SARS-CoV-2 (of which 93% required hospitalization) up to 122 days after symptom onset and compared them to responses in 1548 individuals whose blood samples were obtained prior to the pandemic. After setting seropositivity thresholds for perfect specificity (100%), we estimated sensitivities of 95% for IgG, 90% for IgA, and 81% for IgM for detecting infected individuals between 15 and 28 days after symptom onset. While the median time to seroconversion was nearly 12 days across all three isotypes tested, IgA and IgM antibodies against RBD were short-lived with median times to seroreversion of 71 and 49 days after symptom onset. In contrast, anti-RBD IgG responses decayed slowly through 90 days with only 3 seropositive individuals seroreverting within this time period. IgG antibodies to SARS-CoV-2 RBD were strongly correlated with anti-S neutralizing antibody titers, which demonstrated little to no decrease over 75 days since symptom onset. We observed no cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies with other widely circulating coronaviruses (HKU1, 229 E, OC43, NL63). These data suggest that RBD-targeted antibodies are excellent markers of previous and recent infection, that differential isotype measurements can help distinguish between recent and older infections, and that IgG responses persist over the first few months after infection and are highly correlated with neutralizing antibodies.
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- 2020
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16. Loss of Bcl-6-expressing T follicular helper cells and germinal centers in COVID-19
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Hugues Allard-Chamard, Bruce D. Walker, Jared Feldman, Eric C. Koscher, Jonathan Z. Li, Libera Sessa, Aaron G. Schmidt, Kelsey K. Finn, Hang Liu, Fatema Z. Chowdhury, Pilar Garcia-Broncano, Daniel Lingwood, Jinqing Liu, Xiao-Dong Lian, Ciputra Adijaya Hartana, Ashlin R. Michell, Alex Lee Zhu, Naoki Kaneko, Kevin Einkauf, Ngoc L. Ly, Vinay Mahajan, Xiaoming Sun, Robert F. Padera, Jocelyn R. Farmer, Chenyang Jiang, Paulina Kaplonek, Yelizaveta Rassadkina, Nathalie Bonheur, Shiv Pillai, Timothy M. Caradonna, Hannah J. Ticheli, Marshall Karpell, Sally Shin, Jon Fallon, Julie Boucau, Kristina Lefteri, Josh Chevalier, Kyra Seiger, Mathias Lichterfeld, Alicja Piechocka-Trocha, Nishant K. Singh, Hsiao-Hsuan Kuo, Blake M. Hauser, Weiwei Sun, Matthew Osborn, Yannic C. Bartsch, Michael T. Waring, Thomas J. Diefenbach, Xu G. Yu, Galit Alter, and Julia Bals
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Male ,Cellular differentiation ,Pneumonia, Viral ,Disease ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,Follicular phase ,medicine ,Humans ,Pandemics ,B cell ,030304 developmental biology ,Aged ,Aged, 80 and over ,0303 health sciences ,B-Lymphocytes ,Tumor Necrosis Factor-alpha ,Germinal center ,COVID-19 ,T-Lymphocytes, Helper-Inducer ,Middle Aged ,Germinal Center ,medicine.anatomical_structure ,Immunology ,Humoral immunity ,Proto-Oncogene Proteins c-bcl-6 ,Tumor necrosis factor alpha ,Female ,Coronavirus Infections ,030217 neurology & neurosurgery ,Spleen - Abstract
Summary Humoral responses in COVID-19 disease are often of limited durability, as seen with other human coronavirus epidemics. To address the underlying etiology, we examined postmortem thoracic lymph nodes and spleens in acute SARS-CoV-2 infection and observed the absence of germinal centers, a striking reduction in Bcl-6+ germinal center B cells but preservation of AID+ B cells. Absence of germinal centers correlated with an early specific block in Bcl-6+ TFH cell differentiation together with an increase in T-bet+ TH1 cells and aberrant extra-follicular TNF-α accumulation. Parallel peripheral blood studies revealed loss of transitional and follicular B cells in severe disease and accumulation of SARS-CoV-2-specific “disease-related” B cell populations. These data identify defective Bcl-6+ TFH cell generation and dysregulated humoral immune induction early in COVID-19 disease, providing a mechanistic explanation for the limited durability of antibody responses in coronavirus infections and suggest that achieving herd immunity through natural infection may be difficult., Highlights 1. Acute phase SARS-CoV-2-specific T cells display an activated cytotoxic phenotype 2. Broad and polyfunctional SARS-CoV-2-specific T cell responses in convalescent phase 3. Detection of SARS-CoV-2-specific T cell responses also in seronegative individuals, Buggert and colleagues provide a phenotypic and functional map of SARS-CoV-2-specific T cells across the full spectrum of exposure, infection, and COVID-19 severity. They observe that SARS-CoV-2-specific T cells generate a broad, robust and functionally replete response in convalescent individuals, that may provide protection from recurrent episodes of severe COVID-19.
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- 2020
17. Dynamics and significance of the antibody response to SARS-CoV-2 infection
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Anita S. Iyer, Regina C. LaRocque, Stephanie Fischinger, Diane Yang, Meagan Kelly, Jason B. Harris, Blake M. Hauser, Rachel Mills, Wilfredo F. Garcia-Beltran, Forrest K. Jones, Ariana Nodoushania, Margaret Becker, Aaron G. Schmidt, Tyler E. Miller, Timothy M Cardonna, Dan H. Barouch, Galit Alter, Damien Slater, Jared Feldman, Caroline Atyeo, Michael G Astudillo, Edward T. Ryan, Richelle C. Charles, Stephen A. Lauer, John A. Branda, Anthony J. Iafrate, Stephen B. Calderwood, Zhenfeng Li, Andrew S. Azman, Erica Teng, Guillaume Mellon, Jingyou Yu, Elizabeth Oiver, Mohammad Kamruzzaman, and Sarah E Turbett
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Protective immunity ,biology ,business.industry ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Article ,Serology ,Immune system ,Antibody response ,Immunology ,Cohort ,biology.protein ,Medicine ,Seroprevalence ,Antibody ,business - Abstract
BACKGROUNDCharacterizing the humoral immune response to SARS-CoV-2 and developing accurate serologic assays are needed for diagnostic purposes and estimating population-level seroprevalence.METHODSWe measured the kinetics of early antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in a cohort of 259 symptomatic North American patients infected with SARS-CoV-2 (up to 75 days after symptom onset) compared to antibody levels in 1548 individuals whose blood samples were obtained prior to the pandemic.RESULTSBetween 14-28 days from onset of symptoms, IgG, IgA, or IgM antibody responses to RBD were all accurate in identifying recently infected individuals, with 100% specificity and a sensitivity of 97%, 91%, and 81% respectively. Although the estimated median time to becoming seropositive was similar across isotypes, IgA and IgM antibodies against RBD were short-lived with most individuals estimated to become seronegative again by 51 and 47 days after symptom onset, respectively. IgG antibodies against RBD lasted longer and persisted through 75 days post-symptoms. IgG antibodies to SARS-CoV-2 RBD were highly correlated with neutralizing antibodies targeting the S protein. No cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies was observed with several known circulating coronaviruses, HKU1, OC 229 E, OC43, and NL63.CONCLUSIONSAmong symptomatic SARS-CoV-2 cases, RBD-targeted antibodies can be indicative of previous and recent infection. IgG antibodies are correlated with neutralizing antibodies and are possibly a correlate of protective immunity.
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- 2020
18. Distinct early serological signatures track with SARS-CoV-2 survival
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Matthew D. Slein, Denise J. McCulloch, Timothy M. Caradonna, Dan H. Barouch, Jared Feldman, Todd J. Suscovich, Caitlin R Wolf, Kira L. Newman, Edward T. Ryan, Yongfei Cai, Blake M. Hauser, Richelle C. Charles, John F. Burke, Stephanie Fischinger, Tomer Zohar, Helen Y. Chu, Caroline Atyeo, Galit Alter, Carolin Loos, Douglas A. Lauffenburger, Caitlyn Linde, Aaron G. Schmidt, Kiel Shuey, and Jingyou Yu
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0301 basic medicine ,Adult ,Male ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Immunology ,Pneumonia, Viral ,Medizin ,Antibodies, Viral ,Article ,Serology ,03 medical and health sciences ,Betacoronavirus ,0302 clinical medicine ,Antibody Profile ,Pandemic ,Immunology and Allergy ,Coronavirus Nucleocapsid Proteins ,Humans ,Pandemics ,Aged ,Aged, 80 and over ,biology ,SARS-CoV-2 ,COVID-19 ,Middle Aged ,Nucleocapsid Proteins ,Phosphoproteins ,COVID-19 patients ,SARS-CoV-2-specific antibody ,functional antibody ,Immunity, Humoral ,030104 developmental biology ,Infectious Diseases ,Antibody response ,030220 oncology & carcinogenesis ,Immunoglobulin G ,Humoral immunity ,Cohort ,Spike Glycoprotein, Coronavirus ,biology.protein ,Female ,Antibody ,Coronavirus Infections - Abstract
Summary As SARS-CoV-2 infections and death counts continue to rise, it remains unclear why some individuals recover from infection whereas others rapidly progress and die. While the immunological mechanisms that underlie different clinical trajectories remain poorly defined, pathogen-specific antibodies often point to immunological mechanisms of protection. Here, we profiled SARS-CoV-2–specific humoral responses on a cohort of 22 hospitalized individuals. Despite inter-individual heterogeneity, distinct antibody signatures resolved individuals with different outcomes. While no differences in SARS-CoV-2-specific IgG levels were observed, spike–specific humoral responses were enriched among convalescent individuals, whereas functional antibody responses to the nucleocapsid were elevated in deceased individuals. Furthermore, this enriched immunodominant S-specific antibody profile in convalescents was confirmed in a larger validation cohort. These results demonstrate that early antigen-specific and qualitative features of SARS-CoV-2-specific antibodies, point to differences in disease trajectory, highlighting the potential importance of functional antigen-specific humoral immunity to guide patient care and vaccine development., Graphical Abstract, Highlights • Limited early differences across groups were observed in titers and neutralization • Five antibody features collectively could differentiate convalescents and deceased • A shift in the balance of spike versus nucleocapsid immunity separated the groups • Spike-specific phagocytic and complement fixing activity was enriched in convalescents, Although most SARS-CoV-2 infected individuals experience mild disease, a significant fraction of individuals become severely infected. Early biomarkers that predict outcome are urgently needed. Atyeo et al demonstrate that distinct acute SARS-CoV-2 humoral immune responses exist across severely ill individuals that ultimately convalesce or pass away.
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- 2020
19. SARS-CoV-2 infection protects against rechallenge in rhesus macaques
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Makda S. Gebre, John S. Burke, Peter K. Sorger, Mark G. Lewis, Gabriel Dagotto, Caroline Atyeo, Roland Zahn, Brad Finneyfrock, Xuan He, Laurent Pessaint, Jacob D. Estes, Galit Alter, Linda M. Wrijil, Aaron G. Schmidt, David R. Martinez, Margaret Terry, Abishek Chandrashekar, Jingyou Yu, Kathleen Busman-Sahay, Michael Nekorchuk, Lisa H. Tostanoski, Anthony Cook, Renita Brown, Catherine Jacob-Dolan, Michelle A. Lifton, Dan H. Barouch, Esther A. Bondzie, Zoltan Maliga, Noe B. Mercado, Frank Wegmann, Hanne Andersen, Zhenfeng Li, Matthew D. Slein, Sarah Ducat, Alex Van Ry, Kelvin Blade, Jack Greenhouse, Peter Abbink, Shant H. Mahrokhian, Lauren Peter, Lori F. Maxfield, Stephanie Fischinger, Ralph S. Baric, Nicole Kordana, Andrew D. Miller, Amanda J. Martinot, Joseph P. Nkolola, Katherine McMahan, Jason Velasco, Elyse Teow, Tammy Taylor, Jinyan Liu, and Ramya Nityanandam
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Male ,0301 basic medicine ,viruses ,Antibodies, Viral ,Virus Replication ,0302 clinical medicine ,Recurrence ,Lung ,Research Articles ,Immunity, Cellular ,Multidisciplinary ,biology ,medicine.diagnostic_test ,Viral Load ,Rhesus macaque ,030220 oncology & carcinogenesis ,Viral pneumonia ,Spike Glycoprotein, Coronavirus ,Female ,Antibody ,Coronavirus Infections ,Bronchoalveolar Lavage Fluid ,Viral load ,Research Article ,Pneumonia, Viral ,Immunology ,Betacoronavirus ,03 medical and health sciences ,Immune system ,Immunity ,Virology ,medicine ,Animals ,Pandemics ,SARS-CoV-2 ,business.industry ,R-Articles ,COVID-19 ,biochemical phenomena, metabolism, and nutrition ,medicine.disease ,biology.organism_classification ,Antibodies, Neutralizing ,Macaca mulatta ,Immunity, Humoral ,respiratory tract diseases ,Disease Models, Animal ,Nasal Mucosa ,Pneumonia ,030104 developmental biology ,Bronchoalveolar lavage ,biology.protein ,Lung Diseases, Interstitial ,business ,Immunologic Memory - Abstract
An understanding of protective immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for vaccine and public health strategies aimed at ending the global coronavirus disease 2019 (COVID-19) pandemic. A key unanswered question is whether infection with SARS-CoV-2 results in protective immunity against reexposure. We developed a rhesus macaque model of SARS-CoV-2 infection and observed that macaques had high viral loads in the upper and lower respiratory tract, humoral and cellular immune responses, and pathologic evidence of viral pneumonia. After the initial viral clearance, animals were rechallenged with SARS-CoV-2 and showed 5 log10 reductions in median viral loads in bronchoalveolar lavage and nasal mucosa compared with after the primary infection. Anamnestic immune responses after rechallenge suggested that protection was mediated by immunologic control. These data show that SARS-CoV-2 infection induced protective immunity against reexposure in nonhuman primates.
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- 2020
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20. DNA vaccine protection against SARS-CoV-2 in rhesus macaques
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Mark G. Lewis, Gabriel Dagotto, Frank Wegmann, Joseph P. Nkolola, Yuezhou Chen, Marinela Kirilova, Yongfei Cai, Jason Velasco, Catherine Jacob-Dolan, Shant H. Mahrokhian, John D. Ventura, Nicole Kordana, Esther A. Bondzie, Lisa H. Tostanoski, Felipe J.N. Lelis, Lauren Peter, Roland Zahn, Lori F. Maxfield, Elyse Teow, Makda S. Gebre, Laurent Pessaint, Jinyan Liu, Matthew D. Slein, Adam Zuiani, Ralph S. Baric, David R. Martinez, Bing Chen, John S. Burke, Alan Dodson, Duane R. Wesemann, Jingyou Yu, Xuan He, Brad Finneyfrock, Renita Brown, Alex Van Ry, Dan H. Barouch, Galit Alter, Katherine McMahan, Caroline Atyeo, Anthony Cook, Huahua Wan, Stephanie Fischinger, Aaron G. Schmidt, Kelvin Blade, Meghan Travers, Carolin Loos, Felix Nampanya, Zhenfeng Li, Ramya Nityanandam, Abishek Chandrashekar, Shaghayegh Habibi, Noe B. Mercado, Hanne Andersen, and Zijin Lin
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Male ,viruses ,Antibodies, Viral ,Immunogenicity, Vaccine ,Vaccines, DNA ,Medicine ,Neutralizing antibody ,Research Articles ,Immunity, Cellular ,Multidisciplinary ,biology ,Immunogenicity ,Viral Vaccine ,Vaccination ,Microbio ,Viral Load ,Spike Glycoprotein, Coronavirus ,Female ,Antibody ,Coronavirus Infections ,Viral load ,Bronchoalveolar Lavage Fluid ,Research Article ,COVID-19 Vaccines ,Pneumonia, Viral ,Immunology ,Immunization, Secondary ,DNA vaccination ,Betacoronavirus ,Adjuvants, Immunologic ,Protein Domains ,Immunity ,Animals ,Humans ,Pandemics ,business.industry ,SARS-CoV-2 ,R-Articles ,COVID-19 ,Viral Vaccines ,Virology ,Antibodies, Neutralizing ,Macaca mulatta ,Immunity, Humoral ,Disease Models, Animal ,Nasal Mucosa ,biology.protein ,Mutant Proteins ,business ,Immunologic Memory - Abstract
The global coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made the development of a vaccine a top biomedical priority. In this study, we developed a series of DNA vaccine candidates expressing different forms of the SARS-CoV-2 spike (S) protein and evaluated them in 35 rhesus macaques. Vaccinated animals developed humoral and cellular immune responses, including neutralizing antibody titers at levels comparable to those found in convalescent humans and macaques infected with SARS-CoV-2. After vaccination, all animals were challenged with SARS-CoV-2, and the vaccine encoding the full-length S protein resulted in >3.1 and >3.7 log10 reductions in median viral loads in bronchoalveolar lavage and nasal mucosa, respectively, as compared with viral loads in sham controls. Vaccine-elicited neutralizing antibody titers correlated with protective efficacy, suggesting an immune correlate of protection. These data demonstrate vaccine protection against SARS-CoV-2 in nonhuman primates.
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- 2020
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21. The Loss of Bcl-6 Expressing T Follicular Helper Cells and the Absence of Germinal Centers in COVID-19
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Bruce D. Walker, Alex Lee Zhu, Eric C. Koscher, Xiao-Dong Lian, Sally Shin, Matthias Lichterfeld, Jocelyn R. Farmer, Jon Fallon, Kristina Lefteri, Marshall Karpell, Josh Chevalier, Yelizaveta Rassadkina, Shiv Pillai, Hannah J. Ticheli, Julie Boucau, Vinay Mahajan, Thomas J. Diefenbach, Hugues Allard-Chamard, Ashlin R. Michell, Kelsey K. Finn, Xu G. Yu, Hsiao-Hsuan Kuo, Ciputra Adijaya Hartana, Blake M. Hauser, Michael T. Waring, Jinqing Liu, Daniel Lingwood, Julia Bals, Robert F. Padera, Kevin Einkauf, Matt Osborn, Weiwei Sun, Naoki Kaneko, Ngoc L. Ly, Yannic C. Bartsch, Jared Feldman, Jonathan Z. Li, Kyra Seiger, Hang Liu, Pilar Garcia-Broncano, Alicja Piechocka-Trocha, Nishant K. Singh, Timothy M. Caradonna, Libera Sessa, Aaron G. Schmidt, Nathalie Bonheur, Chenyang Jiang, Paulina Kaplonek, Fatema Z. Chowdhury, and Xiaoming Sun
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business.industry ,Germinal center ,Disease ,Article ,Herd immunity ,Immune system ,medicine.anatomical_structure ,Follicular phase ,Immunology ,medicine ,Etiology ,business ,Pathogen ,B cell - Abstract
Humoral responses in COVID-19 disease are often of limited durability, as seen with other human coronavirus epidemics. To address the underlying etiology, we examined postmortem thoracic lymph nodes and spleens in acute SARS-CoV-2 infection and observed the absence of germinal centers, a striking reduction in Bcl-6+ germinal center B cells but preservation of AID+ B cells. Absence of germinal centers correlated with an early specific block in Bcl-6+TFH cell differentiation together with an increase in T-bet+TH1 cells and aberrant extra-follicular TNF-a accumulation. Parallel peripheral blood studies revealed loss of transitional and follicular B cells in severe disease and accumulation of SARS-CoV-2-specific "disease-related" B cell populations. These data identify defective Bcl-6+TFH cell generation and dysregulated humoral immune induction early in COVID-19 disease, providing a mechanistic explanation for the limited durability of antibody responses in coronavirus infections and suggest that achieving herd immunity through natural infection may be difficult. Funding: This work was supported by NIH U19 AI110495 to SP, NIH R01 AI146779 to AGS, NIH R01AI137057 and DP2DA042422 to DL, BMH was supported by NIGMS T32 GM007753, TMC was supported by T32 AI007245. Funding for these studies from the Massachusetts Consortium of Pathogen Readiness, the Mark and Lisa Schwartz Foundation and Enid Schwartz is also acknowledged. Conflict of Interest: None. Ethical Approval: This study was performed with the approval of the Institutional Review Boards at the Massachusetts General Hospital and the Brigham and Women's Hospital.
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- 2020
22. In vitro and in vivo functions of SARS-CoV-2 infection-enhancing and neutralizing antibodies
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Mark G. Lewis, Andrew N. Macintyre, Robert Parks, Fangping Cai, S. Munir Alam, Dapeng Li, Trevor Scobey, Alexandra Schäfer, Timothy M. Caradonna, C. Todd DeMarco, Kevin W. Bock, Ian N. Moore, Kedamawit Tilahun, Charlene McDanal, Thomas H. Oguin, I-Ting Teng, Priyamvada Acharya, Andrew Foulger, Tarra Von Holle, Elizabeth Petzold, Longping V. Tse, Christopher W. Woods, Megan Kopp, Robert J. Edwards, Bianca M. Nagata, Mahnaz Minai, M. Anthony Moody, Thomas N. Denny, Victoria Gee-Lai, John R. Mascola, Sophie M. C. Gobeil, Kevin Wiehe, Lautaro G. Perez, Tongqing Zhou, Chuancang Jiang, Kevin O. Saunders, David C. Montefiori, Aja Sanzone, Erica Stover, Katarzyna Janowska, Kartik Manne, Gregory D. Sempowski, Peter D. Kwong, Barton F. Haynes, Blake M. Hauser, Wes Rountree, Derek W. Cain, David R. Martinez, Barney S. Graham, Maggie Barr, Esther J. Lee, Ralph S. Baric, Kenneth D. Cronin, Margaret Deyton, Victoria Stalls, Xiaozhi Lu, Jared Feldman, Katayoun Mansouri, Hanne Leth Andersen, Laura L. Sutherland, Giovanna Hernandez, Robert A. Seder, Yunfei Wang, and Aaron G. Schmidt
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Male ,N-terminal domain ,viruses ,Fc receptor ,Inflammation ,Antibodies, Viral ,Virus Replication ,Article ,General Biochemistry, Genetics and Molecular Biology ,Virus ,infection enhancement ,Proinflammatory cytokine ,Mice ,Protein Domains ,In vivo ,medicine ,Animals ,Humans ,antibody-dependent enhancement ,skin and connective tissue diseases ,Lung ,Mice, Inbred BALB C ,biology ,medicine.diagnostic_test ,SARS-CoV-2 ,Receptors, IgG ,cross-neutralization ,fungi ,electron micrograph ,COVID-19 ,neutralizing antibody ,Haplorhini ,Viral Load ,respiratory system ,Antibodies, Neutralizing ,In vitro ,respiratory tract diseases ,Bronchoalveolar lavage ,in vivo protection ,Spike Glycoprotein, Coronavirus ,Immunology ,biology.protein ,Cytokines ,Female ,receptor-binding domain ,Antibody ,medicine.symptom ,Bronchoalveolar Lavage Fluid ,RNA, Guide, Kinetoplastida - Abstract
SARS-CoV-2-neutralizing antibodies (NAbs) protect against COVID-19. A concern regarding SARS-CoV-2 antibodies is whether they mediate disease enhancement. Here, we isolated NAbs against the receptor-binding domain (RBD) or the N-terminal domain (NTD) of SARS-CoV-2 spike from individuals with acute or convalescent SARS-CoV-2 or a history of SARS-CoV infection. Cryo-electron microscopy of RBD and NTD antibodies demonstrated function-specific modes of binding. Select RBD NAbs also demonstrated Fc receptor-γ (FcγR)-mediated enhancement of virus infection in vitro, while five non-neutralizing NTD antibodies mediated FcγR-independent in vitro infection enhancement. However, both types of infection-enhancing antibodies protected from SARS-CoV-2 replication in monkeys and mice. Three of 46 monkeys infused with enhancing antibodies had higher lung inflammation scores compared to controls. One monkey had alveolar edema and elevated bronchoalveolar lavage inflammatory cytokines. Thus, while in vitro antibody-enhanced infection does not necessarily herald enhanced infection in vivo, increased lung inflammation can rarely occur in SARS-CoV-2 antibody-infused macaques., Graphical abstract, Convalescent human-derived SARS-CoV-2 RBD and NTD antibodies mediated neutralization as well as infection enhancement in vitro, yet infusion of these antibodies in mice or cynomolgus macaques resulted in suppression of virus replication.
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- 2021
23. Immune focusing to a broadly protective subdominant viral epitope by antigen engineering
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Kevin J. McCarthy, Yu Adachi, Yoshimasa Takahashi, Masayuki Kuraoka, Taishi Onodera, Garnett Kelsoe, Goran Bajic, Max J. Maron, Charles E. McGee, Aaron G. Schmidt, and Gregory D. Sempowski
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Subdominant ,Immune system ,Antigen ,Immunology ,Genetics ,Biology ,Molecular Biology ,Biochemistry ,Epitope ,Biotechnology - Published
- 2019
24. Quick COVID-19 Healers Sustain Anti-SARS-CoV-2 Antibody Production
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Yongfei Cai, Michael S. Seaman, Krista M. Pullen, Deborah Gakpo, Duane R. Wesemann, Bing Chen, James A. Lederer, Douglas A. Lauffenburger, Jared Feldman, Aaron G. Schmidt, Pei Tong, Adam Zuiani, John S. Burke, Alejandro B. Balazs, Junrui Lin, Evan C. Lam, Hannah Martin, Avneesh Gautam, Jyotsna Mullur, Blake M. Hauser, Jillian C. Bensko, Timothy M. Caradonna, Stephanie Fischinger, Caroline Atyeo, Christy L. Lavine, Felipe J.N. Lelis, Yuezhou Chen, Meghan Travers, Shaghayegh Habibi, and Galit Alter
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CD4-Positive T-Lymphocytes ,Somatic hypermutation ,Antibodies, Viral ,Lymphocyte Activation ,medicine.disease_cause ,Article ,General Biochemistry, Genetics and Molecular Biology ,Immunoglobulin G ,Serology ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,medicine ,Humans ,Memory B cell ,030304 developmental biology ,0303 health sciences ,Mutation ,biology ,SARS-CoV-2 ,COVID-19 ,Germinal center ,Antibody Formation ,Immunology ,biology.protein ,Antibody ,030217 neurology & neurosurgery - Abstract
Antibodies are key immune effectors that confer protection against pathogenic threats. The nature and longevity of the antibody response to SARS-CoV-2 infection is not well defined. We charted longitudinal antibody responses to SARS-CoV-2 in 92 subjects after symptomatic COVID-19. Antibody responses to SARS-CoV-2 are unimodally distributed over a broad range, with symptom severity correlating directly with virus-specific antibody magnitude. Seventy-six subjects followed longitudinally to ∼100 days demonstrated marked heterogeneity in antibody duration dynamics. Virus-specific IgG decayed substantially in most individuals, whereas a distinct subset had stable or increasing antibody levels in the same timeframe despite similar initial antibody magnitudes. These individuals with increasing responses recovered rapidly from symptomatic COVID-19 disease, harbored increased somatic mutations in virus-specific memory B cell antibody genes, and had persistent higher frequencies of previously activated CD4+ T cells. These findings illuminate an efficient immune phenotype that connects rapid symptom clearance to differential antibody durability dynamics., Highlights SARS-CoV-2 antibody responses range from negligible to robust in mild COVID-19 Some individuals maintain stable or increased SARS-CoV-2 IgG, while most decline Those who sustain virus-specific IgG production tend to have shorter disease courses Virus-specific B cells from “sustainers” have more SHM early after disease resolution, Longitudinal analyses of antibody responses to SARS-CoV-2 demonstrate that individuals with sustained virus-specific IgG production have shorter disease trajectories, with a subset demonstrating increased somatic hypermutation and higher levels of activated CD4+ cells.
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- 2020
25. Compromised Humoral Functional Evolution Tracks with SARS-CoV-2 Mortality
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Timothy M. Caradonna, Caroline Atyeo, Blake M. Hauser, Yongfei Cai, Hendrik Streeck, Jingyou Yu, Carolin Loos, Dan H. Barouch, Jared Feldman, Edward T. Ryan, Stephanie Fischinger, Tomer Zohar, Galit Alter, Matthew D. Slein, John F. Burke, Aaron G. Schmidt, Chuangqi Wang, Douglas A. Lauffenburger, and Richelle C. Charles
- Subjects
Male ,Fc-receptors ,Population ,Medizin ,HL-60 Cells ,Disease ,Article ,General Biochemistry, Genetics and Molecular Biology ,Neutralization ,03 medical and health sciences ,0302 clinical medicine ,Immunity ,Humans ,antibodies ,education ,innate immunity ,030304 developmental biology ,0303 health sciences ,education.field_of_study ,Innate immune system ,biology ,SARS-CoV-2 ,Effector ,Receptors, IgG ,COVID-19 ,dynamics ,Immunity, Humoral ,Immunoglobulin A ,Immunoglobulin M ,Humoral immunity ,Immunology ,biology.protein ,Female ,sense organs ,Antibody ,030217 neurology & neurosurgery - Abstract
The urgent need for an effective SARS-CoV-2 vaccine has forced development to progress in the absence of well-defined correlates of immunity. While neutralization has been linked to protection against other pathogens, whether neutralization alone will be sufficient to drive protection against SARS-CoV-2 in the broader population remains unclear. Therefore, to fully define protective humoral immunity we dissected the early evolution of the humoral response in 193 hospitalized individuals ranging from moderate-to severe. Although robust IgM and IgA responses evolved in both survivors and non-survivors with severe disease, non-survivors showed attenuated IgG responses, accompanied by compromised Fcɣ-receptor binding and Fc-effector activity, pointing to deficient humoral development rather than disease-enhancing humoral immunity. In contrast, individuals with moderate disease exhibited delayed responses that ultimately matured. These data highlight distinct humoral trajectories associated with resolution of SARS-CoV-2 infection and the need for early functional humoral immunity., Highlights ● IgA and IgM evolve rapidly across all levels of disease severity ● Rapid and potent IgG class switching is linked to survival ● Moderate disease is associated with a delay but ultimate convergence of IgG ● Early S2-cross-reactivity is linked to survival after severe disease, Analyses of the functional humoral trajectories associated with the resolution of SARS-CoV-2 infection find that in spite of equivalent IgM and IgA immunity to the virus across all levels of disease severity, survival and recovery is linked to early class switching to IgG and the ability to leverage Fcγ-receptors targeting the spike protein.
- Published
- 2020
26. Complex Antigens Drive Permissive Clonal Selection in Germinal Centers
- Author
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Stephen C. Harrison, Aaron G. Schmidt, Thomas B. Kepler, Masayuki Kuraoka, Feng Feng, Garnett Kelsoe, Akiko Watanabe, Daisuke Kitamura, and Takuya Nojima
- Subjects
0301 basic medicine ,Immunogen ,Bacterial Toxins ,Immunology ,Naive B cell ,Population ,Antibody Affinity ,Hemagglutinins, Viral ,Receptors, Antigen, B-Cell ,Biology ,Article ,Epitope ,Affinity maturation ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Animals ,Humans ,Immunology and Allergy ,Clonal Selection, Antigen-Mediated ,education ,Cells, Cultured ,Genetics ,Antigens, Bacterial ,B-Lymphocytes ,Mice, Inbred BALB C ,education.field_of_study ,Germinal center ,Antibody Diversity ,Single-Domain Antibodies ,Germinal Center ,Orthomyxoviridae ,Immunity, Humoral ,Mice, Inbred C57BL ,030104 developmental biology ,Infectious Diseases ,Female ,030215 immunology - Abstract
Germinal center (GC) B cells evolve towards increased affinity by a Darwinian process that has been studied primarily in genetically restricted, hapten-specific responses. We explored the population dynamics of genetically diverse GC responses to two complex antigens – Bacillus anthracis protective antigen and influenza hemagglutinin – in which B cells competed both intra- and interclonally for distinct epitopes. Preferred VH rearrangements among antigen-binding, naïve B cells were similarly abundant in early GCs but, unlike responses to haptens, clonal diversity increased in GC B cells as early “winners” were replaced by rarer, high-affinity clones. Despite affinity maturation, inter- and intraclonal avidities varied greatly, and half of GC B cells did not bind the immunogen but nonetheless exhibited biased VH use, V(D)J mutation, and clonal expansion comparable to antigen-binding cells. GC reactions to complex antigens permit a range of specificities and affinities, with potential advantages for broad protection.
- Published
- 2016
27. Memory B cells that cross-react with group 1 and group 2 influenza A viruses are abundant in adult human repertoires
- Author
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Charles E. McGee, Stephen C. Harrison, Khoi T. Do, Garnett Kelsoe, Aaron G. Schmidt, Thomas B. Kepler, Akiko Watanabe, Gregory D. Sempowski, Masayuki Kuraoka, and Kevin R. McCarthy
- Subjects
0301 basic medicine ,Adult ,Male ,Lineage (genetic) ,Immunology ,Population ,Cell Culture Techniques ,Hemagglutinins, Viral ,Biology ,Cross Reactions ,Antibodies, Viral ,Article ,Affinity maturation ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Immunology and Allergy ,Humans ,education ,Gene ,B cell ,education.field_of_study ,B-Lymphocytes ,breakpoint cluster region ,Flow Cytometry ,Virology ,030104 developmental biology ,Infectious Diseases ,medicine.anatomical_structure ,Interferometry ,Immunization ,Influenza A virus ,biology.protein ,Female ,Antibody ,030215 immunology - Abstract
Human B cell antigen-receptor (BCR) repertoires reflect repeated exposures to evolving influenza viruses; new exposures update the previously generated B cell memory (Bmem) population. Despite structural similarity of hemagglutinins (HAs) from the two groups of influenza A viruses, cross-reacting antibodies (Abs) are uncommon. We analyzed Bmem compartments in three unrelated, adult donors and found frequent cross-group, BCRs, both HA-head directed and non-head directed. Members of a clonal lineage from one donor had a BCR structure similar to that of a previously described Ab, encoded by different gene segments. Comparison showed that both Abs contacted the HA receptor-binding site through long heavy-chain third complementarity determining regions. Affinities of the clonal-lineage BCRs for historical influenza-virus HAs from both group 1 and group 2 viruses suggested that serial responses to seasonal influenza exposures had elicited the lineage and driven affinity maturation. We propose that appropriate immunization regimens might elicit a comparably broad response.
- Published
- 2018
28. Peptide Inhibitors of Flavivirus Entry Derived from the E Protein Stem
- Author
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Aaron G. Schmidt, Stephen C. Harrison, and Priscilla L. Yang
- Subjects
Molecular Sequence Data ,Immunology ,Peptide ,Dengue virus ,medicine.disease_cause ,Microbiology ,Virus ,Dengue ,Viral Envelope Proteins ,Aedes ,Viral entry ,Virology ,Vaccines and Antiviral Agents ,medicine ,Animals ,Amino Acid Sequence ,Serotyping ,Peptide sequence ,Cells, Cultured ,chemistry.chemical_classification ,Infectivity ,biology ,Virion ,Virion membrane ,Dengue Virus ,Virus Internalization ,biology.organism_classification ,Peptide Fragments ,Flavivirus ,chemistry ,Insect Science ,Mutation ,Hydrophobic and Hydrophilic Interactions - Abstract
Peptides derived from the “stem” of dengue virus (DV) type 2 (DV2) envelope (E) protein inhibit DV2 infectivity, targeting a late-stage fusion intermediate. We show here that stem peptides from all DV serotypes cross-inhibit DV1 to DV4 but that corresponding peptides derived from related flaviviruses do not. This failure to inhibit infection is not due to poor interaction with the E protein but rather to loss of association with the virion membrane. Residues 442 to 444 of the stem are determinants of inhibition; increasing hydrophobicity in this region increases inhibitory strength. These results support a two-step model of how stem-derived peptides inhibit viral entry.
- Published
- 2010
29. Functional Interrogation and Mining of Natively-Paired Human VH:VL Antibody Repertoires
- Author
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Brandon J. DeKosky, Bo Wang, Morgan Timm, Jiwon Lee, Erica Normandin, John Misasi, Rui Kong, Jonathan R. McDaniel, George Delidakis, Kendra E. Leigh, Thomas Niezold, Aurélie Ploquin, Elise G. Viox, Ahmed Fahad, Alberto Cagigi, Kwanyee Leung, Eun Sung Yang, Wing-Pui Kong, William Voss, Aaron G. Schmidt, M. Anthony Moody, David Ambrozak, Amy R. Henry, Farida Laboune, Julie E. Ledgerwood, Barney S. Graham, Mark Connors, Daniel C. Douek, Nancy Sullivan, Andrew D. Ellington, and George Georgiou
- Subjects
Immunology ,Immunology and Allergy - Abstract
Next-Generation sequencing has become an essential tool in the analysis of antibody responses in the settings of health, vaccination, and disease. However, immune receptors comprise two chains encoded by separate mRNA strands, and conventional NextGen sequencing fails to identify the native pairings encoded by individual lymphocytes. To overcome this limitation we have applied recent technical advances in high-throughput sequencing and functional analysis of complete antibodies (i.e., paired heavy and light chain sequencing) to generate a comprehensive understanding of the antibody response to vaccination and natural infection. Here we present a new technology to screen natively-paired human antibody repertoires from millions of B cells. Libraries of natively-paired variable region heavy and light (VH:VL) amplicons were expressed in a yeast display platform that was optimized for human Fab surface expression, and the resulting libraries were interrogated for binding to viral vaccine antigens via FACS paired with next generation sequencing. Using our method we identified HIV-1 broadly neutralizing antibodies (bNAbs) from an HIV-1 slow progressor and high-affinity neutralizing antibodies responding to an Ebola virus glycoprotein vaccination. These next-generation approaches are providing detailed molecular feedback on immune receptor responses and are informing the design and discovery of new vaccines and therapeutics.
- Published
- 2018
30. B-Cell Selection in Germinal Centers Elicited by Complex Antigens
- Author
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Masayuki Kuraoka, Aaron G. Schmidt, Takuya Nojima, Feng Feng, Akiko Watanabe, Daisuke Kitamura, Stephen C. Harrison, Thomas B. Kepler, and Garnett Kelsoe
- Subjects
Immunology ,Immunology and Allergy - Abstract
Germinal center (GC) B cells evolve towards increased affinity by a Darwinian process studied intensively in genetically restricted, hapten-specific responses. While experimentally tractable, genetically restricted humoral responses are atypical as antibodies to complex protein antigens represent genetically diverse, polyclonal humoral responses driven by various epitopes arrayed across the antigen. We have developed a single B-cell culture method that supports the proliferation and plasmacytic differentiation of mature and GC B cells. With this tool, we explore the population dynamics of genetically diverse GC responses to two complex antigens – protective antigen of Bacillus anthracis and influenza hemagglutinin – in which B cells compete both intra- and interclonally for distinct epitopes. Our characterizations begin with antigen-binding, mature naïve B cells and follow clonal selection and affinity maturation in GCs. Preferred VH rearrangements among antigen-binding, naïve B cells were similarly abundant in early GCs but, unlike restricted responses to haptens, clonal diversity increased in GC B cells as early “winners” were replaced by rarer, high affinity clones. Despite affinity maturation, half of GC B cells did not detectably bind immunogen but exhibited genetic selection comparable to antigen-binding cells, as determined by VH usage, mutations, and clonal expansion. In GCs elicited by rPA or rHA, interclonal BCR avidities can differ 100-fold and intraclonal avidity by as much as 40-fold. We propose that intraclonal selection in GCs is permissive for a wide range of BCR affinities and that lower affinity/less fit GC B cells may remain viable in GCs for substantially longer periods than generally thought.
- Published
- 2016
31. Peptide inhibitors of dengue-virus entry target a late-stage fusion intermediate
- Author
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Stephen C. Harrison, Priscilla L. Yang, and Aaron G. Schmidt
- Subjects
lcsh:Immunologic diseases. Allergy ,Conformational change ,Endosome ,Immunology ,Biology ,Microbiology ,Antiviral Agents ,Virology/Emerging Viral Diseases ,03 medical and health sciences ,Viral Envelope Proteins ,Viral entry ,Biochemistry/Protein Chemistry ,Virology ,Genetics ,Animals ,Molecular Biology ,Integral membrane protein ,lcsh:QH301-705.5 ,030304 developmental biology ,Virology/Antivirals, including Modes of Action and Resistance ,0303 health sciences ,Cell fusion ,030306 microbiology ,Virion ,Lipid bilayer fusion ,Dengue Virus ,Virus Internalization ,Transmembrane protein ,Virology/New Therapies, including Antivirals and Immunotherapy ,Biochemistry ,Ectodomain ,lcsh:Biology (General) ,Biophysics ,Parasitology ,Biochemistry/Drug Discovery ,Peptides ,lcsh:RC581-607 ,Research Article - Abstract
The mechanism of membrane fusion by “class II” viral fusion proteins follows a pathway that involves large-scale domain rearrangements of the envelope glycoprotein (E) and a transition from dimers to trimers. The rearrangement is believed to proceed by an outward rotation of the E ectodomain after loss of the dimer interface, followed by a reassociation into extended trimers. The ∼55-aa-residue, membrane proximal “stem” can then zip up along domain II, bringing together the transmembrane segments of the C-terminus and the fusion loops at the tip of domain II. We find that peptides derived from the stem of dengue-virus E bind stem-less E trimer, which models a conformational intermediate. In vitro assays demonstrate that these peptides specifically block viral fusion. The peptides inhibit infectivity with potency proportional to their affinity for the conformational intermediate, even when free peptide is removed from a preincubated inoculum before infecting cells. We conclude that peptides bind virions before attachment and are carried with virions into endosomes, the compartment in which acidification initiates fusion. Binding depends on particle dynamics, as there is no inhibition of infectivity if preincubation and separation are at 4°C rather than 37°C. We propose a two-step model for the mechanism of fusion inhibition. Targeting a viral entry pathway can be an effective way to block infection. Our data, which support and extend proposed mechanisms for how the E conformational change promotes membrane fusion, suggest strategies for inhibiting flavivirus entry., Author Summary Enveloped viruses must overcome a succession of cellular barriers before establishing infection. One obstacle is fusion of viral and cellular membranes. Rearrangements of proteins on the viral surface facilitate fusion and subsequent delivery of the viral genome into the cytosol. In this study, we probed the fusion-promoting rearrangement of the dengue-virus envelope (E) protein. Peptides derived from the membrane proximal “stem” of E bind to a form of recombinant E that represents a late-stage intermediate in its low-pH triggered conformational change. The binding mimics a key step in the fusion-promoting process. We find that these stem peptides also inhibit viral infectivity, with potency proportional to their affinity for E, and that they do so by specifically blocking fusion. We provide evidence that inhibition is a two-step process: an initial, nonspecific interaction of the peptide with the viral membrane, followed by specific binding to E, as the protein undergoes conformational rearrangement. The initial step explains how the virus can carry the peptide into an endosome—a necessary step, because the binding surface on E becomes available only after exposure to low pH. This work extends the model of flavivirus fusion, and suggests strategies for targeting viruses that penetrate from endosomes.
- Published
- 2010
32. Escape and compensation from early HLA-B57-mediated cytotoxic T-lymphocyte pressure on human immunodeficiency virus type 1 Gag alter capsid interactions with cyclophilin A
- Author
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Bruce D. Walker, Susan Allen, Paul A. Goepfert, Eric Hunter, Faina Ryvkin, Matthew P. Lahaie, Joseph Mulenga, Arne Schneidewind, Todd M. Allen, Ivna DeSouza, Toshiyuki Miura, Aaron G. Schmidt, Cynthia A. Derdeyn, and Mark A. Brockman
- Subjects
Protein Conformation ,Immunology ,Molecular Sequence Data ,Cypa ,HIV Infections ,Human leukocyte antigen ,medicine.disease_cause ,Virus Replication ,Microbiology ,gag Gene Products, Human Immunodeficiency Virus ,Virus ,Capsid ,Virology ,Drug Resistance, Viral ,HLA-B Antigens ,medicine ,Cytotoxic T cell ,Humans ,Amino Acid Sequence ,Mutation ,biology ,Immunodominant Epitopes ,Virion ,Viral Load ,biology.organism_classification ,Viral replication ,Insect Science ,HIV-1 ,Pathogenesis and Immunity ,Cyclophilin A ,CD8 ,T-Lymphocytes, Cytotoxic - Abstract
Certain histocompatibility leukocyte antigen (HLA) alleles are associated with improved clinical outcomes for individuals infected with human immunodeficiency virus type 1 (HIV-1), but the mechanisms for their effects remain undefined. An early CD8+T-cell escape mutation in the dominant HLA-B57-restricted Gag epitope TW10 (TSTLQEQIGW) has been shown to impair HIV-1 replication capacity in vitro. We demonstrate here that this T242N substitution in the capsid protein is associated with upstream mutations at residues H219, I223, and M228in the cyclophilin A (CypA)-binding loop in B57+individuals with progressive disease. In an independent cohort of epidemiologically linked transmission pairs, the presence of these substitutions in viruses encoding T242N was associated with significantly higher plasma viremia in donors, further suggesting that these secondary mutations compensated for the replication defect of T242N. Using NL4-3 constructs, we illustrate the ability of these CypA loop changes to partially restore replication of the T242N variant in vitro. Notably, these mutations also enhanced viral resistance to the drug cyclosporine A, indicating a reduced dependence of the compensated virus on CypA that is normally essential for optimal infectivity. Therefore, mutations in TW10 allow HIV-1 to evade a dominant early CD8+T-cell response, but the benefits of escape are offset by a defect in capsid function. These data suggest that TW10 escape variants undergo a postentry block that is partially overcome by changes in the CypA-binding loop and identify a mechanism for an HIV-1 fitness defect that may contribute to the slower disease progression associated with HLA-B57.
- Published
- 2007
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