BACKGROUND. Plasmodium vivax is the most widespread human malaria geographically; however, no effective vaccine exists. Red blood cell invasion by the P. vivax merozoite depends on an interaction between the Duffy antigen receptor for chemokines (DARC) and region II of the parasite’s Duffy-binding protein (PvDBP_RII). Naturally acquired binding-inhibitory antibodies against this interaction associate with clinical immunity, but it is unknown whether these responses can be induced by human vaccination. METHODS. Safety and immunogenicity of replication-deficient chimpanzee adenovirus serotype 63 (ChAd63) and modified vaccinia virus Ankara (MVA) viral vectored vaccines targeting PvDBP_RII (Salvador I strain) were assessed in an open-label dose-escalation phase Ia study in 24 healthy UK adults. Vaccines were delivered by the intramuscular route in a ChAd63-MVA heterologous prime-boost regimen using an 8-week interval. RESULTS. Both vaccines were well tolerated and demonstrated a favorable safety profile in malaria-naive adults. PvDBP_RII–specific ex-vivo IFN-γ T cell, antibody-secreting cell, memory B cell, and serum IgG responses were observed after the MVA boost immunization. Vaccine-induced antibodies inhibited the binding of vaccine homologous and heterologous variants of recombinant PvDBP_RII to the DARC receptor, with median 50% binding-inhibition titers greater than 1:100. CONCLUSION. We have demonstrated for the first time to our knowledge that strain-transcending antibodies can be induced against the PvDBP_RII antigen by vaccination in humans. These vaccine candidates warrant further clinical evaluation of efficacy against the blood-stage P. vivax parasite. TRIAL REGISTRATION. Clinicaltrials.gov NCT01816113. FUNDING. Support was provided by the UK Medical Research Council, UK National Institute of Health Research Oxford Biomedical Research Centre, and the Wellcome Trust.
Ruth O. Payne, Sarah E. Silk, Sean C. Elias, Kathryn H. Milne, Thomas A. Rawlinson, David Llewellyn, A. Rushdi Shakri, Jing Jin, Geneviève M. Labbé, Nick J. Edwards, Ian D. Poulton, Rachel Roberts, Ryan Farid, Thomas Jørgensen, Daniel G.W. Alanine, Simone C. de Cassan, Matthew K. Higgins, Thomas D. Otto, James S. McCarthy, Willem A. de Jongh, Alfredo Nicosia, Sarah Moyle, Adrian V.S. Hill, Eleanor Berrie, Chetan E. Chitnis, Alison M. Lawrie, Simon J. Draper
Zika virus (ZIKV) is an emerging mosquito-transmitted flavivirus that shares a considerable degree of homology with dengue virus (DENV). Here, we examined longitudinal antibody response against ZIKV during natural infection in 2 convalescent individuals. By decomposing the antibody recognition into DI/DII and DIII of the E glycoprotein, we showed their development in humans followed a spatiotemporal hierarchy. Plasma binding to DI/DII appeared to peak and wane during early infection with extensive cross-reactivity with DI/DII of DENV. Binding to DIII, however, peaked early but persisted months into the infection without detectable cross-reactivity with DIII of DENV. A clear trend of increase in DIII-specific neutralizing activity was observed over the course of infection. mAbs isolated during early infection are largely DI/DII specific, weakly neutralizing, and highly cross-reactive with DENV, while those from later infection are more diverse in recognition, potently neutralizing, and ZIKV specific. The most potent neutralizing mAb targeting the DIII provided 100% protection in mice from lethal ZIKV infection and could therefore serve as a promising candidate for antibody-based therapy and prevention. The dynamic features unveiled here will assist us to better understand the pathogenesis of ZIKV infection and inform rational design of vaccines.
Lei Yu, Ruoke Wang, Fei Gao, Min Li, Jianying Liu, Jian Wang, Wenxin Hong, Lingzhai Zhao, Yingfen Wen, Chibiao Yin, Hua Wang, Qi Zhang, Yangyang Li, Panpan Zhou, Rudian Zhang, Yang Liu, Xiaoping Tang, Yongjun Guan, Cheng-Feng Qin, Ling Chen, Xuanling Shi, Xia Jin, Gong Cheng, Fuchun Zhang, Linqi Zhang
A major challenge for studying authentic liver cell function and cell replacement therapies is that primary human hepatocytes rapidly lose their advanced function in conventional, 2-dimensional culture platforms. Here, we describe the fabrication of 3-dimensional hexagonally arrayed lobular human liver tissues inspired by the liver’s natural architecture. The engineered liver tissues exhibit key features of advanced differentiation, such as human-specific cytochrome P450–mediated drug metabolism and the ability to support efficient infection with patient-derived inoculums of hepatitis C virus. The tissues permit the assessment of antiviral agents and maintain their advanced functions for over 5 months in culture. This extended functionality enabled the prediction of a fatal human-specific hepatotoxicity caused by fialuridine (FIAU), which had escaped detection by preclinical models and short-term clinical studies. The results obtained with the engineered human liver tissue in this study provide proof-of-concept determination of human-specific drug metabolism, demonstrate the ability to support infection with human hepatitis virus derived from an infected patient and subsequent antiviral drug testing against said infection, and facilitate detection of human-specific drug hepatotoxicity associated with late-onset liver failure. Looking forward, the scalability and biocompatibility of the scaffold are also ideal for future cell replacement therapeutic strategies.
Soon Seng Ng, Anming Xiong, Khanh Nguyen, Marilyn Masek, Da Yoon No, Menashe Elazar, Eyal Shteyer, Mark A. Winters, Amy Voedisch, Kate Shaw, Sheikh Tamir Rashid, Curtis W. Frank, Nam Joon Cho, Jeffrey S. Glenn
Initial promising results with immune sera guided early human mAb approaches against Gram-negative sepsis to an LPS neutralization mechanism, but these efforts failed in human clinical trials. Emergence of multidrug resistance has renewed interest in pathogen-specific mAbs. We utilized a pair of antibodies targeting
Taylor S. Cohen, Mark Pelletier, Lily Cheng, Meghan E. Pennini, Jessica Bonnell, Romana Cvitkovic, Chew-shun Chang, Xiaodong Xiao, Elisabetta Cameroni, Davide Corti, Elena Semenova, Paul Warrener, Bret R. Sellman, JoAnn Suzich, Qun Wang, C. Kendall Stover
Here, we report the isolation of broadly neutralizing mAbs (bNAbs) from persons with broadly neutralizing serum who spontaneously cleared hepatitis C virus (HCV) infection. We found that bNAbs from two donors bound the same epitope and were encoded by the same germline heavy chain variable gene segment. Remarkably, these bNAbs were encoded by antibody variable genes with sparse somatic mutations. For one of the most potent bNAbs, these somatic mutations were critical for antibody neutralizing breadth and for binding to autologous envelope variants circulating late in infection. However, somatic mutations were not necessary for binding of the bNAb unmutated ancestor to envelope proteins of early autologous transmitted/founder viruses. This study identifies a public B cell clonotype favoring early recognition of a conserved HCV epitope, proving that anti-HCV bNAbs can achieve substantial neutralizing breadth with relatively few somatic mutations, and identifies HCV envelope variants that favored selection and maturation of an anti-HCV bNAb in vivo. These data provide insight into the molecular mechanisms of immune-mediated clearance of HCV infection and present a roadmap to guide development of a vaccine capable of stimulating anti-HCV bNAbs with a physiologic number of somatic mutations characteristic of vaccine responses.
Justin R. Bailey, Andrew I. Flyak, Valerie J. Cohen, Hui Li, Lisa N. Wasilewski, Anna E. Snider, Shuyi Wang, Gerald H. Learn, Nurgun Kose, Leah Loerinc, Rebecca Lampley, Andrea L. Cox, Jennifer M. Pfaff, Benjamin J. Doranz, George M. Shaw, Stuart C. Ray, James E. Crowe Jr.
Development of antiviral therapy against acute viral diseases, such as dengue virus (DENV), suffers from the narrow window of viral load detection in serum during onset and clearance of infection and fever. We explored a biomarker approach using 18F-fluorodeoxyglucose (18F-FDG) PET in established mouse models for primary and antibody-dependent enhancement infection with DENV. 18F-FDG uptake was most prominent in the intestines and correlated with increased virus load and proinflammatory cytokines. Furthermore, a significant temporal trend in 18F-FDG uptake was seen in intestines and selected tissues over the time course of infection. Notably, 18F-FDG uptake and visualization by PET robustly differentiated treatment-naive groups from drug-treated groups as well as nonlethal from lethal infections with a clinical strain of DENV2. Thus, 18F-FDG may serve as a novel DENV infection–associated inflammation biomarker for assessing treatment response during therapeutic intervention trials.
Ann-Marie Chacko, Satoru Watanabe, Keira J. Herr, Shirin Kalimuddin, Jing Yang Tham, Joanne Ong, Marie Reolo, Raymond M.F. Serrano, Yin Bun Cheung, Jenny G.H. Low, Subhash G. Vasudevan
Perforin-2 is a highly conserved pore-forming protein encoded by macrophage expressed gene 1 (
Ryan M. McCormack, Eva P. Szymanski, Amy P. Hsu, Elena Perez, Kenneth N. Olivier, Eva Fisher, E. Brook Goodhew, Eckhard R. Podack, Steven M. Holland
Zika virus (ZIKV) infections have been linked with neurological complications and congenital Zika syndrome. Given the high level of homology between ZIKV and the related flavivirus dengue virus (DENV), we investigated the level of cross-reactivity with ZIKV using a panel of DENV human mAbs. A majority of the mAbs showed binding to ZIKV virions, with several exhibiting neutralizing capacities against ZIKV in vitro. Three of the best ZIKV-neutralizing mAbs were found to recognize diverse epitopes on the envelope (E) glycoprotein: the highly conserved fusion-loop peptide, a conformation-specific epitope on the E monomer, and a quaternary epitope on the virion surface. The most potent ZIKV-neutralizing mAb (SIgN-3C) was assessed in 2 type I interferon receptor–deficient (
Yiu-Wing Kam, Cheryl Yi-Pin Lee, Teck-Hui Teo, Shanshan W. Howland, Siti Naqiah Amrun, Fok-Moon Lum, Peter See, Nicholas Qing-Rong Kng, Roland G. Huber, Mei-Hui Xu, Heng-Liang Tan, Andre Choo, Sebastian Maurer-Stroh, Florent Ginhoux, Katja Fink, Cheng-I Wang, Lisa F.P. Ng, Laurent Rénia
IL-21 has been shown to play an important role in the CD8 T cell response during acute and chronic viral infections. However, the role of IL-21 signaling in the CD4 T cell response to viral infection remains incompletely defined. In a model of infection with vaccinia virus, we show that intrinsic IL-21 signaling on CD4 T cells was critical for the formation of memory CD4 T cells in vivo. We further reveal that IL-21 promoted CD4 T cell survival in a mechanism dependent on activation of the STAT1 and STAT3 signaling pathways. In addition, the activation of Akt is also required for IL-21–dependent survival of CD4 T cells in vivo. These results identify a critical role for intrinsic IL-21 signaling in CD4 T cell survival and memory formation in response to viral infection in vivo and may provide insights into the design of effective vaccine strategies.
Yuqing Yuan, Yiping Yang, Xiaopei Huang
Melanie A. Gasper, Anneke C. Hesseling, Isaac Mohar, Landon Myer, Tali Azenkot, Jo-Ann S. Passmore, Willem Hanekom, Mark F. Cotton, I. Nicholas Crispe, Donald L. Sodora, Heather B. Jaspan
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