Browsing by Author "Bonsignori, Mattia"

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    Assessment of Simulated Surveillance Testing and Quarantine in a SARS-CoV-2-Vaccinated Population of Students on a University Campus.
    (JAMA health forum, 2021-10) Motta, Francis C; McGoff, Kevin A; Deckard, Anastasia; Wolfe, Cameron R; Bonsignori, Mattia; Moody, M Anthony; Cavanaugh, Kyle; Denny, Thomas N; Harer, John; Haase, Steven B

    Importance

    The importance of surveillance testing and quarantine on university campuses to limit SARS-CoV-2 transmission needs to be reevaluated in the context of a complex and rapidly changing environment that includes vaccines, variants, and waning immunity. Also, recent US Centers for Disease Control and Prevention guidelines suggest that vaccinated students do not need to participate in surveillance testing.

    Objective

    To evaluate the use of surveillance testing and quarantine in a fully vaccinated student population for whom vaccine effectiveness may be affected by the type of vaccination, presence of variants, and loss of vaccine-induced or natural immunity over time.

    Design setting and participants

    In this simulation study, an agent-based Susceptible, Exposed, Infected, Recovered model was developed with some parameters estimated using data from the 2020 to 2021 academic year at Duke University (Durham, North Carolina) that described a simulated population of 5000 undergraduate students residing on campus in residential dormitories. This study assumed that 100% of residential undergraduates are vaccinated. Under varying levels of vaccine effectiveness (90%, 75%, and 50%), the reductions in the numbers of positive cases under various mitigation strategies that involved surveillance testing and quarantine were estimated.

    Main outcomes and measures

    The percentage of students infected with SARS-CoV-2 each day for the course of the semester (100 days) and the total number of isolated or quarantined students were estimated.

    Results

    A total of 5000 undergraduates were simulated in the study. In simulations with 90% vaccine effectiveness, weekly surveillance testing was associated with only marginally reduced viral transmission. At 50% to 75% effectiveness, surveillance testing was estimated to reduce the number of infections by as much as 93.6%. A 10-day quarantine protocol for exposures was associated with only modest reduction in infections until vaccine effectiveness dropped to 50%. Increased testing of reported contacts was estimated to be at least as effective as quarantine at limiting infections.

    Conclusions and relevance

    In this simulated modeling study of infection dynamics on a college campus where 100% of the student body is vaccinated, weekly surveillance testing was associated with a substantial reduction of campus infections with even a modest loss of vaccine effectiveness. Model simulations also suggested that an increased testing cadence can be as effective as a 10-day quarantine period at limiting infections. Together, these findings provide a potential foundation for universities to design appropriate mitigation protocols for the 2021 to 2022 academic year.
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    Correction: Neutralization-guided design of HIV-1 envelope trimers with high affinity for the unmutated common ancestor of CH235 lineage CD4bs broadly neutralizing antibodies.
    (PLoS pathogens, 2019-12-02) LaBranche, Celia C; Henderson, Rory; Hsu, Allen; Behrens, Shay; Chen, Xuejun; Zhou, Tongqing; Wiehe, Kevin; Saunders, Kevin O; Alam, S Munir; Bonsignori, Mattia; Borgnia, Mario J; Sattentau, Quentin J; Eaton, Amanda; Greene, Kelli; Gao, Hongmei; Liao, Hua-Xin; Williams, Wilton B; Peacock, James; Tang, Haili; Perez, Lautaro G; Edwards, Robert J; Kepler, Thomas B; Korber, Bette T; Kwong, Peter D; Mascola, John R; Acharya, Priyamvada; Haynes, Barton F; Montefiori, David C
    [This corrects the article DOI: 10.1371/journal.ppat.1008026.].
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    Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies.
    (Cell, 2021-05-18) Williams, Wilton B; Meyerhoff, R Ryan; Edwards, RJ; Li, Hui; Manne, Kartik; Nicely, Nathan I; Henderson, Rory; Zhou, Ye; Janowska, Katarzyna; Mansouri, Katayoun; Gobeil, Sophie; Evangelous, Tyler; Hora, Bhavna; Berry, Madison; Abuahmad, A Yousef; Sprenz, Jordan; Deyton, Margaret; Stalls, Victoria; Kopp, Megan; Hsu, Allen L; Borgnia, Mario J; Stewart-Jones, Guillaume BE; Lee, Matthew S; Bronkema, Naomi; Moody, M Anthony; Wiehe, Kevin; Bradley, Todd; Alam, S Munir; Parks, Robert J; Foulger, Andrew; Oguin, Thomas; Sempowski, Gregory D; Bonsignori, Mattia; LaBranche, Celia C; Montefiori, David C; Seaman, Michael; Santra, Sampa; Perfect, John; Francica, Joseph R; Lynn, Geoffrey M; Aussedat, Baptiste; Walkowicz, William E; Laga, Richard; Kelsoe, Garnett; Saunders, Kevin O; Fera, Daniela; Kwong, Peter D; Seder, Robert A; Bartesaghi, Alberto; Shaw, George M; Acharya, Priyamvada; Haynes, Barton F
    Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.
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    Functional Relevance of Improbable Antibody Mutations for HIV Broadly Neutralizing Antibody Development.
    (Cell host & microbe, 2018-06) Wiehe, Kevin; Bradley, Todd; Meyerhoff, R Ryan; Hart, Connor; Williams, Wilton B; Easterhoff, David; Faison, William J; Kepler, Thomas B; Saunders, Kevin O; Alam, S Munir; Bonsignori, Mattia; Haynes, Barton F
    HIV-1 broadly neutralizing antibodies (bnAbs) require high levels of activation-induced cytidine deaminase (AID)-catalyzed somatic mutations for optimal neutralization potency. Probable mutations occur at sites of frequent AID activity, while improbable mutations occur where AID activity is infrequent. One bottleneck for induction of bnAbs is the evolution of viral envelopes (Envs) that can select bnAb B cell receptors (BCR) with improbable mutations. Here we define the probability of bnAb mutations and demonstrate the functional significance of key improbable mutations in three bnAb B cell lineages. We show that bnAbs are enriched for improbable mutations, which implies that their elicitation will be critical for successful vaccine induction of potent bnAb B cell lineages. We discuss a mutation-guided vaccine strategy for identification of Envs that can select B cells with BCRs that have key improbable mutations required for bnAb development.
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    IDLV-HIV-1 Env vaccination in non-human primates induces affinity maturation of antigen-specific memory B cells.
    (Communications biology, 2018-01) Blasi, Maria; Negri, Donatella; LaBranche, Celia; Alam, S Munir; Baker, Erich J; Brunner, Elizabeth C; Gladden, Morgan A; Michelini, Zuleika; Vandergrift, Nathan A; Wiehe, Kevin J; Parks, Robert; Shen, Xiaoying; Bonsignori, Mattia; Tomaras, Georgia D; Ferrari, Guido; Montefiori, David C; Santra, Sampa; Haynes, Barton F; Moody, Michael A; Cara, Andrea; Klotman, Mary E
    HIV continues to be a major global health issue. In spite of successful prevention interventions and treatment methods, the development of an HIV vaccine remains a major priority for the field and would be the optimal strategy to prevent new infections. We showed previously that a single immunization with a SIV-based integrase-defective lentiviral vector (IDLV) expressing the 1086.C HIV-1-envelope induced durable, high-magnitude immune responses in non-human primates (NHPs). In this study, we have further characterized the humoral responses by assessing antibody affinity maturation and antigen-specific memory B-cell persistence in two vaccinated macaques. These animals were also boosted with IDLV expressing the heterologous 1176.C HIV-1-Env to determine if neutralization breadth could be increased, followed by evaluation of the injection sites to assess IDLV persistence. IDLV-Env immunization was associated with persistence of the vector DNA for up to 6 months post immunization and affinity maturation of antigen-specific memory B cells.
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    Immune checkpoint modulation enhances HIV-1 antibody induction.
    (Nature communications, 2020-02-19) Bradley, Todd; Kuraoka, Masayuki; Yeh, Chen-Hao; Tian, Ming; Chen, Huan; Cain, Derek W; Chen, Xuejun; Cheng, Cheng; Ellebedy, Ali H; Parks, Robert; Barr, Maggie; Sutherland, Laura L; Scearce, Richard M; Bowman, Cindy M; Bouton-Verville, Hilary; Santra, Sampa; Wiehe, Kevin; Lewis, Mark G; Ogbe, Ane; Borrow, Persephone; Montefiori, David; Bonsignori, Mattia; Anthony Moody, M; Verkoczy, Laurent; Saunders, Kevin O; Ahmed, Rafi; Mascola, John R; Kelsoe, Garnett; Alt, Frederick W; Haynes, Barton F
    Eliciting protective titers of HIV-1 broadly neutralizing antibodies (bnAbs) is a goal of HIV-1 vaccine development, but current vaccine strategies have yet to induce bnAbs in humans. Many bnAbs isolated from HIV-1-infected individuals are encoded by immunoglobulin gene rearrangments with infrequent naive B cell precursors and with unusual genetic features that may be subject to host regulatory control. Here, we administer antibodies targeting immune cell regulatory receptors CTLA-4, PD-1 or OX40 along with HIV envelope (Env) vaccines to rhesus macaques and bnAb immunoglobulin knock-in (KI) mice expressing diverse precursors of CD4 binding site HIV-1 bnAbs. CTLA-4 blockade augments HIV-1 Env antibody responses in macaques, and in a bnAb-precursor mouse model, CTLA-4 blocking or OX40 agonist antibodies increase germinal center B and T follicular helper cells and plasma neutralizing antibodies. Thus, modulation of CTLA-4 or OX40 immune checkpoints during vaccination can promote germinal center activity and enhance HIV-1 Env antibody responses.
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    Implementation of a Pooled Surveillance Testing Program for Asymptomatic SARS-CoV-2 Infections on a College Campus - Duke University, Durham, North Carolina, August 2-October 11, 2020.
    (MMWR. Morbidity and mortality weekly report, 2020-11-20) Denny, Thomas N; Andrews, Laura; Bonsignori, Mattia; Cavanaugh, Kyle; Datto, Michael B; Deckard, Anastasia; DeMarco, C Todd; DeNaeyer, Nicole; Epling, Carol A; Gurley, Thaddeus; Haase, Steven B; Hallberg, Chloe; Harer, John; Kneifel, Charles L; Lee, Mark J; Louzao, Raul; Moody, M Anthony; Moore, Zack; Polage, Christopher R; Puglin, Jamie; Spotts, P Hunter; Vaughn, John A; Wolfe, Cameron R
    On university campuses and in similar congregate environments, surveillance testing of asymptomatic persons is a critical strategy (1,2) for preventing transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). All students at Duke University, a private research university in Durham, North Carolina, signed the Duke Compact (3), agreeing to observe mandatory masking, social distancing, and participation in entry and surveillance testing. The university implemented a five-to-one pooled testing program for SARS-CoV-2 using a quantitative, in-house, laboratory-developed, real-time reverse transcription-polymerase chain reaction (RT-PCR) test (4,5). Pooling of specimens to enable large-scale testing while minimizing use of reagents was pioneered during the human immunodeficiency virus pandemic (6). A similar methodology was adapted for Duke University's asymptomatic testing program. The baseline SARS-CoV-2 testing plan was to distribute tests geospatially and temporally across on- and off-campus student populations. By September 20, 2020, asymptomatic testing was scaled up to testing targets, which include testing for residential undergraduates twice weekly, off-campus undergraduates one to two times per week, and graduate students approximately once weekly. In addition, in response to newly identified positive test results, testing was focused in locations or within cohorts where data suggested an increased risk for transmission. Scale-up over 4 weeks entailed redeploying staff members to prepare 15 campus testing sites for specimen collection, developing information management tools, and repurposing laboratory automation to establish an asymptomatic surveillance system. During August 2-October 11, 68,913 specimens from 10,265 graduate and undergraduate students were tested. Eighty-four specimens were positive for SARS-CoV-2, and 51% were among persons with no symptoms. Testing as a result of contact tracing identified 27.4% of infections. A combination of risk-reduction strategies and frequent surveillance testing likely contributed to a prolonged period of low transmission on campus. These findings highlight the importance of combined testing and contact tracing strategies beyond symptomatic testing, in association with other preventive measures. Pooled testing balances resource availability with supply-chain disruptions, high throughput with high sensitivity, and rapid turnaround with an acceptable workload.
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    Infectious virion capture by HIV-1 gp120-specific IgG from RV144 vaccinees.
    (J Virol, 2013-07) Liu, Pinghuang; Yates, Nicole L; Shen, Xiaoying; Bonsignori, Mattia; Moody, M Anthony; Liao, Hua-Xin; Fong, Youyi; Alam, S Munir; Overman, R Glenn; Denny, Thomas; Ferrari, Guido; Ochsenbauer, Christina; Kappes, John C; Polonis, Victoria R; Pitisuttithum, Punnee; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Rerks-Ngarm, Supachai; Montefiori, David C; Gilbert, Peter; Michael, Nelson L; Kim, Jerome H; Haynes, Barton F; Tomaras, Georgia D
    The detailed examination of the antibody repertoire from RV144 provides a unique template for understanding potentially protective antibody functions. Some potential immune correlates of protection were untested in the correlates analyses due to inherent assay limitations, as well as the need to keep the correlates analysis focused on a limited number of endpoints to achieve statistical power. In an RV144 pilot study, we determined that RV144 vaccination elicited antibodies that could bind infectious virions (including the vaccine strains HIV-1 CM244 and HIV-1 MN and an HIV-1 strain expressing transmitted/founder Env, B.WITO.c). Among vaccinees with the highest IgG binding antibody profile, the majority (78%) captured the infectious vaccine strain virus (CM244), while a smaller proportion of vaccinees (26%) captured HIV-1 transmitted/founder Env virus. We demonstrated that vaccine-elicited HIV-1 gp120 antibodies of multiple specificities (V3, V2, conformational C1, and gp120 conformational) mediated capture of infectious virions. Although capture of infectious HIV-1 correlated with other humoral immune responses, the extent of variation between these humoral responses and virion capture indicates that virion capture antibodies occupy unique immunological space.
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    Initiation of HIV neutralizing B cell lineages with sequential envelope immunizations.
    (Nature communications, 2017-11-23) Williams, Wilton B; Zhang, Jinsong; Jiang, Chuancang; Nicely, Nathan I; Fera, Daniela; Luo, Kan; Moody, M Anthony; Liao, Hua-Xin; Alam, S Munir; Kepler, Thomas B; Ramesh, Akshaya; Wiehe, Kevin; Holland, James A; Bradley, Todd; Vandergrift, Nathan; Saunders, Kevin O; Parks, Robert; Foulger, Andrew; Xia, Shi-Mao; Bonsignori, Mattia; Montefiori, David C; Louder, Mark; Eaton, Amanda; Santra, Sampa; Scearce, Richard; Sutherland, Laura; Newman, Amanda; Bouton-Verville, Hilary; Bowman, Cindy; Bomze, Howard; Gao, Feng; Marshall, Dawn J; Whitesides, John F; Nie, Xiaoyan; Kelsoe, Garnett; Reed, Steven G; Fox, Christopher B; Clary, Kim; Koutsoukos, Marguerite; Franco, David; Mascola, John R; Harrison, Stephen C; Haynes, Barton F; Verkoczy, Laurent
    A strategy for HIV-1 vaccine development is to define envelope (Env) evolution of broadly neutralizing antibodies (bnAbs) in infection and to recreate those events by vaccination. Here, we report host tolerance mechanisms that limit the development of CD4-binding site (CD4bs), HCDR3-binder bnAbs via sequential HIV-1 Env vaccination. Vaccine-induced macaque CD4bs antibodies neutralize 7% of HIV-1 strains, recognize open Env trimers, and accumulate relatively modest somatic mutations. In naive CD4bs, unmutated common ancestor knock-in mice Env+B cell clones develop anergy and partial deletion at the transitional to mature B cell stage, but become Env- upon receptor editing. In comparison with repetitive Env immunizations, sequential Env administration rescue anergic Env+ (non-edited) precursor B cells. Thus, stepwise immunization initiates CD4bs-bnAb responses, but immune tolerance mechanisms restrict their development, suggesting that sequential immunogen-based vaccine regimens will likely need to incorporate strategies to expand bnAb precursor pools.
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    Recapitulation of HIV-1 Env-antibody coevolution in macaques leading to neutralization breadth.
    (Science (New York, N.Y.), 2020-11-19) Roark, Ryan S; Li, Hui; Williams, Wilton B; Chug, Hema; Mason, Rosemarie D; Gorman, Jason; Wang, Shuyi; Lee, Fang-Hua; Rando, Juliette; Bonsignori, Mattia; Hwang, Kwan-Ki; Saunders, Kevin O; Wiehe, Kevin; Moody, M Anthony; Hraber, Peter T; Wagh, Kshitij; Giorgi, Elena E; Russell, Ronnie M; Bibollet-Ruche, Frederic; Liu, Weimin; Connell, Jesse; Smith, Andrew G; DeVoto, Julia; Murphy, Alexander I; Smith, Jessica; Ding, Wenge; Zhao, Chengyan; Chohan, Neha; Okumura, Maho; Rosario, Christina; Ding, Yu; Lindemuth, Emily; Bauer, Anya M; Bar, Katharine J; Ambrozak, David; Chao, Cara W; Chuang, Gwo-Yu; Geng, Hui; Lin, Bob C; Louder, Mark K; Nguyen, Richard; Zhang, Baoshan; Lewis, Mark G; Raymond, Donald D; Doria-Rose, Nicole A; Schramm, Chaim A; Douek, Daniel C; Roederer, Mario; Kepler, Thomas B; Kelsoe, Garnett; Mascola, John R; Kwong, Peter D; Korber, Bette T; Harrison, Stephen C; Haynes, Barton F; Hahn, Beatrice H; Shaw, George M
    Neutralizing antibodies elicited by HIV-1 coevolve with viral envelope proteins (Env) in distinctive patterns, in some cases acquiring substantial breadth. We report that primary HIV-1 envelope proteins-when expressed by simian-human immunodeficiency viruses in rhesus macaques-elicited patterns of Env-antibody coevolution strikingly similar to those in humans. This included conserved immunogenetic, structural and chemical solutions to epitope recognition and precise Env-am ino acid substitutions, insertions and deletions leading to virus persistence. The structure of one rhesus antibody, capable of neutralizing 49% of a 208-strain panel, revealed a V2-apex mode of recognition like that of human bNAbs PGT145/PCT64-35S. Another rhesus antibody bound the CD4-binding site by CD4 mimicry mirroring human bNAbs 8ANC131/CH235/VRC01. Virus-antibody coevolution in macaques can thus recapitulate developmental features of human bNAbs, thereby guiding HIV-1 immunogen design.
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    Two distinct broadly neutralizing antibody specificities of different clonal lineages in a single HIV-1-infected donor: implications for vaccine design.
    (J Virol, 2012-04) Bonsignori, Mattia; Montefiori, David C; Wu, Xueling; Chen, Xi; Hwang, Kwan-Ki; Tsao, Chun-Yen; Kozink, Daniel M; Parks, Robert J; Tomaras, Georgia D; Crump, John A; Kapiga, Saidi H; Sam, Noel E; Kwong, Peter D; Kepler, Thomas B; Liao, Hua-Xin; Mascola, John R; Haynes, Barton F
    Plasma from a small subset of subjects chronically infected with HIV-1 shows remarkable magnitude and breadth of neutralizing activity. From one of these individuals (CH0219), we isolated two broadly neutralizing antibodies (bnAbs), CH01 and VRC-CH31, from two clonal lineages of memory B cells with distinct specificities (variable loop 1 and 2 [V1V2] conformational specificity and CD4-binding site specificity, respectively) that recapitulate 95% of CH0219 serum neutralization breadth. These data provide proof of concept for an HIV-1 vaccine that aims to elicit bnAbs of multiple specificities.