ORCID Profile
0000-0002-0049-1079
Current Organisations
Vanderbilt University School of Medicine
,
Vanderbilt University Medical Center
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Publisher: Public Library of Science (PLoS)
Date: 23-02-2021
DOI: 10.1371/JOURNAL.PPAT.1009331
Abstract: Different strains within a dengue serotype (DENV1-4) can have smooth, or “bumpy” surface morphologies with different antigenic characteristics at average body temperature (37°C). We determined the neutralizing properties of a serotype cross-reactive human monoclonal antibody (HMAb) 1C19 for strains with differing morphologies within the DENV1 and DENV2 serotypes. We mapped the 1C19 epitope to E protein domain II by hydrogen deuterium exchange mass spectrometry, cryoEM and molecular dynamics simulations, revealing that this epitope is likely partially hidden on the virus surface. We showed the antibody has high affinity for binding to recombinant DENV1 E proteins compared to those of DENV2, consistent with its strong neutralizing activities for all DENV1 strains tested regardless of their morphologies. This finding suggests that the antibody could out-compete E-to-E interaction for binding to its epitope. In contrast, for DENV2, HMAb 1C19 can only neutralize when the epitope becomes exposed on the bumpy-surfaced particle. Although HMAb 1C19 is not a suitable therapeutic candidate, this study with HMAb 1C19 shows the importance of choosing a high-affinity antibody that could neutralize erse dengue virus morphologies for therapeutic purposes.
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.STR.2017.07.007
Abstract: Uncovering mechanisms of antibody-mediated neutralization for viral infections requires epitope and paratope mapping in the context of whole viral particle interactions with the antibody in solution. In this study, we use amide hydrogen/deuterium exchange mass spectrometry to describe the interface of a dengue virus-neutralizing antibody, 2D22, with its target epitope. 2D22 binds specifically to DENV2, a serotype showing strain-specific structural expansion at human host physiological temperatures of 37°C. Our results identify the heavy chain of 2D22 to be the primary determinant for binding DENV2. Temperature-mediated expansion alters the mode of interaction of 2D22 binding. Importantly, 2D22 interferes with the viral expansion process and offers a basis for its neutralization mechanism. The relative magnitude of deuterium exchange protection upon antibody binding across the various epitope loci allows a deconstruction of the antibody-viral interface in host-specific environments and offers a robust approach for targeted antibody engineering.
Publisher: Cold Spring Harbor Laboratory
Date: 18-02-2021
DOI: 10.1101/2021.02.17.431743
Abstract: Hendra virus (HeV) and Nipah virus (NiV), the prototypic members of the Henipavirus (HNV) genus, are emerging, zoonotic paramyxoviruses known to cause severe disease across six mammalian orders, including humans (Eaton et al., 2006). While several research groups have made strides in developing candidate vaccines and therapeutics against henipaviruses, such countermeasures have not been licensed for human use, and significant gaps in knowledge about the human immune response to these viruses exist. To address these gaps, we isolated a large panel of human monoclonal antibodies (mAbs) from the B cells of an in idual with prior occupation-related exposure to the equine HeV vaccine (Equivac® HeV). Competition-binding and hydrogen-deuterium exchange mass spectrometry (HDX-MS) studies identified at least six distinct antigenic sites on the HeV/NiV receptor binding protein (RBP) that are recognized by human mAbs. Antibodies recognizing multiple antigenic sites potently neutralized NiV and/or HeV isolates in vitro. The most potent class of cross-reactive antibodies achieved neutralization by blocking viral attachment to the host cell receptors ephrin-B2 and ephrin-B3. Antibodies from this class mimic receptor binding by inducing a receptor-bound conformation to the HeV-RBP protein tetramer, exposing an epitope that appears to lie hidden in the interface between protomers within the HeV-RBP tetramer. Antibodies that recognize this cryptic epitope potently neutralized HeV and NiV. Flow cytometric studies using cell-surface-displayed HeV-RBP protein showed that cross-reactive, neutralizing mAbs from each of these classes cooperate for binding. In a highly stringent hamster model of NiV B infection, antibodies from both classes reduced morbidity and mortality and achieved synergistic protection in combination and provided therapeutic benefit when combined into two bispecific platforms. These studies identified multiple candidate mAbs that might be suitable for use in a cocktail therapeutic approach to achieve synergistic antiviral potency and reduce the risk of virus escape during treatment.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Public Library of Science (PLoS)
Date: 16-01-2020
Publisher: Elsevier BV
Date: 08-2017
Publisher: Springer Science and Business Media LLC
Date: 20-02-2015
DOI: 10.1038/NCOMMS7341
Abstract: Dengue virus (DENV) infects ~400 million people annually. There is no licensed vaccine or therapeutic drug. Only a small fraction of the total DENV-specific antibodies in a naturally occurring dengue infection consists of highly neutralizing antibodies. Here we show that the DENV-specific human monoclonal antibody 5J7 is exceptionally potent, neutralizing 50% of virus at nanogram-range antibody concentration. The 9 Å resolution cryo-electron microscopy structure of the Fab 5J7–DENV complex shows that a single Fab molecule binds across three envelope proteins and engages three functionally important domains, each from a different envelope protein. These domains are critical for receptor binding and fusion to the endosomal membrane. The ability to bind to multiple domains allows the antibody to fully coat the virus surface with only 60 copies of Fab, that is, half the amount compared with other potent antibodies. Our study reveals a highly efficient and unusual mechanism of molecular recognition by an antibody.
Publisher: American Society for Microbiology
Date: 02-2013
DOI: 10.1128/JVI.02152-12
Abstract: The extracellular virion form (EV) of vaccinia virus (VACV) is essential for viral pathogenesis and is difficult to neutralize with antibodies. Why this is the case and how the smallpox vaccine overcomes this challenge remain incompletely understood. We previously showed that high concentrations of anti-B5 antibodies are insufficient to directly neutralize EV (M. R. Benhnia, et al., J. Virol. 83:1201–1215, 2009). This allowed for at least two possible interpretations: covering the EV surface is insufficient for neutralization, or there are insufficient copies of B5 to allow anti-B5 IgG to cover the whole surface of EV and another viral receptor protein remains active. We endeavored to test these possibilities, focusing on the antibody responses elicited by immunization against smallpox. We tested whether human monoclonal antibodies (MAbs) against the three major EV antigens, B5, A33, and A56, could in idually or together neutralize EV. While anti-B5 or anti-A33 (but not anti-A56) MAbs of appropriate isotypes were capable of neutralizing EV in the presence of complement, a mixture of anti-B5, anti-A33, and anti-A56 MAbs was incapable of directly neutralizing EV, even at high concentrations. This remained true when neutralizing the IHD-J strain, which lacks a functional version of the fourth and final known EV surface protein, A34. These immunological data are consistent with the possibility that viral proteins may not be the active component of the EV surface for target cell binding and infectivity. We conclude that the protection afforded by the smallpox vaccine anti-EV response is predominantly mediated not by direct neutralization but by isotype-dependent effector functions, such as complement recruitment for antibodies targeting B5 and A33.
Publisher: Elsevier BV
Date: 06-2018
Publisher: EMBO
Date: 14-01-2014
Publisher: Springer Science and Business Media LLC
Date: 10-07-2018
DOI: 10.1038/S41467-018-04704-9
Abstract: The high rate of antigenic drift in seasonal influenza viruses necessitates frequent changes in vaccine composition. Recent seasonal H3 vaccines do not protect against swine-origin H3N2 variant (H3N2v) strains that recently have caused severe human infections. Here, we report a human V H 1-69 gene-encoded monoclonal antibody (mAb) designated H3v-47 that exhibits potent cross-reactive neutralization activity against human and swine H3N2 viruses that circulated since 1989. The crystal structure and electron microscopy reconstruction of H3v-47 Fab with the H3N2v hemagglutinin (HA) identify a unique epitope spanning the vestigial esterase and receptor-binding subdomains that is distinct from that of any known neutralizing antibody for influenza A H3 viruses. MAb H3v-47 functions largely by blocking viral egress from infected cells. Interestingly, H3v-47 also engages Fcγ receptor and mediates antibody dependent cellular cytotoxicity (ADCC). This newly identified conserved epitope can be used in design of novel immunogens for development of broadly protective H3 vaccines.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-07-2015
Abstract: Mosquito-borne dengue virus (DENV) is a growing public health threat. Nearly 400 million people are infected annually, and no vaccine is currently available. Fibriansah et al. report that a human antibody (2D22) specific for DENV serotype 2, when given therapeutically, can protect mice from a lethal form of this virus. Structural analysis revealed that 2D22 binds across multiple DENV envelope proteins, which probably blocks the ability of these proteins to assemble into the orientation necessary for viral entry. The epitope where 2D22 binds to the virus may therefore represent a potential vaccine target. Science , this issue p. 88
Publisher: Elsevier BV
Date: 02-2019
Location: United States of America
Location: United States of America
Location: United States of America
No related grants have been discovered for James Crowe.