Browsing by Author "Vandergrift, Nathan"

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    Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated.
    (J Exp Med, 2011-10-24) Liao, Hua-Xin; Chen, Xi; Munshaw, Supriya; Zhang, Ruijun; Marshall, Dawn J; Vandergrift, Nathan; Whitesides, John F; Lu, Xiaozhi; Yu, Jae-Sung; Hwang, Kwan-Ki; Gao, Feng; Markowitz, Martin; Heath, Sonya L; Bar, Katharine J; Goepfert, Paul A; Montefiori, David C; Shaw, George C; Alam, S Munir; Margolis, David M; Denny, Thomas N; Boyd, Scott D; Marshal, Eleanor; Egholm, Michael; Simen, Birgitte B; Hanczaruk, Bozena; Fire, Andrew Z; Voss, Gerald; Kelsoe, Garnett; Tomaras, Georgia D; Moody, M Anthony; Kepler, Thomas B; Haynes, Barton F
    The initial antibody response to HIV-1 is targeted to envelope (Env) gp41, and is nonneutralizing and ineffective in controlling viremia. To understand the origins and characteristics of gp41-binding antibodies produced shortly after HIV-1 transmission, we isolated and studied gp41-reactive plasma cells from subjects acutely infected with HIV-1. The frequencies of somatic mutations were relatively high in these gp41-reactive antibodies. Reverted unmutated ancestors of gp41-reactive antibodies derived from subjects acutely infected with HIV-1 frequently did not react with autologous HIV-1 Env; however, these antibodies were polyreactive and frequently bound to host or bacterial antigens. In one large clonal lineage of gp41-reactive antibodies, reactivity to HIV-1 Env was acquired only after somatic mutations. Polyreactive gp41-binding antibodies were also isolated from uninfected individuals. These data suggest that the majority of gp41-binding antibodies produced after acute HIV-1 infection are cross-reactive responses generated by stimulating memory B cells that have previously been activated by non-HIV-1 antigens.
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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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    Maternal HIV-1 envelope-specific antibody responses and reduced risk of perinatal transmission.
    (J Clin Invest, 2015-07-01) Permar, Sallie R; Fong, Youyi; Vandergrift, Nathan; Fouda, Genevieve G; Gilbert, Peter; Parks, Robert; Jaeger, Frederick H; Pollara, Justin; Martelli, Amanda; Liebl, Brooke E; Lloyd, Krissey; Yates, Nicole L; Overman, R Glenn; Shen, Xiaoying; Whitaker, Kaylan; Chen, Haiyan; Pritchett, Jamie; Solomon, Erika; Friberg, Emma; Marshall, Dawn J; Whitesides, John F; Gurley, Thaddeus C; Von Holle, Tarra; Martinez, David R; Cai, Fangping; Kumar, Amit; Xia, Shi-Mao; Lu, Xiaozhi; Louzao, Raul; Wilkes, Samantha; Datta, Saheli; Sarzotti-Kelsoe, Marcella; Liao, Hua-Xin; Ferrari, Guido; Alam, S Munir; Montefiori, David C; Denny, Thomas N; Moody, M Anthony; Tomaras, Georgia D; Gao, Feng; Haynes, Barton F
    Despite the wide availability of antiretroviral drugs, more than 250,000 infants are vertically infected with HIV-1 annually, emphasizing the need for additional interventions to eliminate pediatric HIV-1 infections. Here, we aimed to define humoral immune correlates of risk of mother-to-child transmission (MTCT) of HIV-1, including responses associated with protection in the RV144 vaccine trial. Eighty-three untreated, HIV-1-transmitting mothers and 165 propensity score-matched nontransmitting mothers were selected from the Women and Infants Transmission Study (WITS) of US nonbreastfeeding, HIV-1-infected mothers. In a multivariable logistic regression model, the magnitude of the maternal IgG responses specific for the third variable loop (V3) of the HIV-1 envelope was predictive of a reduced risk of MTCT. Neutralizing Ab responses against easy-to-neutralize (tier 1) HIV-1 strains also predicted a reduced risk of peripartum transmission in secondary analyses. Moreover, recombinant maternal V3-specific IgG mAbs mediated neutralization of autologous HIV-1 isolates. Thus, common V3-specific Ab responses in maternal plasma predicted a reduced risk of MTCT and mediated autologous virus neutralization, suggesting that boosting these maternal Ab responses may further reduce HIV-1 MTCT.
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    Statistical methods for the assessment of EQAPOL proficiency testing: ELISpot, Luminex, and Flow Cytometry.
    (Journal of Immunological Methods, 2014-07) Rountree, Wes; Vandergrift, Nathan; Bainbridge, John; Sanchez, Ana M; Denny, Thomas N
    In September 2011 Duke University was awarded a contract to develop the National Institutes of Health/National Institute of Allergy and Infectious Diseases (NIH/NIAID) External Quality Assurance Program Oversight Laboratory (EQAPOL). Through EQAPOL, proficiency testing programs are administered for Interferon-γ (IFN-γ) Enzyme-linked immunosorbent spot (ELISpot), Intracellular Cytokine Staining Flow Cytometry (ICS) and Luminex-based cytokine assays. One of the charges of the EQAPOL program was to apply statistical methods to determine overall site performance. We utilized various statistical methods for each program to find the most appropriate for assessing laboratory performance using the consensus average as the target value. Accuracy ranges were calculated based on Wald-type confidence intervals, exact Poisson confidence intervals, or via simulations. Given the nature of proficiency testing data, which has repeated measures within donor/sample made across several laboratories; the use of mixed effects models with alpha adjustments for multiple comparisons was also explored. Mixed effects models were found to be the most useful method to assess laboratory performance with respect to accuracy to the consensus. Model based approaches to the proficiency testing data in EQAPOL will continue to be utilized. Mixed effects models also provided a means of performing more complex analyses that would address secondary research questions regarding within and between laboratory variability as well as longitudinal analyses.