Infectious disease
Abstract
Clinical responses to infection or vaccination and the development of effective immunity are characterized in humans by a marked interindividual variability. To gain an insight into the factors affecting this variability, we used a controlled human infection system to study early immune events following primary infection of healthy human volunteers with blood-stage Plasmodium falciparum malaria. By day 4 of infection, a dichotomous pattern of high or low expression of a defined set of microRNAs (miRs) emerged in volunteers that correlated with variation in parasite growth rate. Moreover, high-miR responders had higher numbers of activated CD4+ T cells, and developed significantly enhanced antimalarial antibody responses. Notably, a set of 17 miRs was identified in the whole blood of low-miR responders prior to infection that differentiated them from high-miR responders. These data implicate preexisting host factors as major determinants in the ability to effectively respond to primary malaria infection.
Authors
Julie G. Burel, Simon H. Apte, Penny L. Groves, Michelle J. Boyle, Christine Langer, James G. Beeson, James S. McCarthy, Denise L. Doolan
Abstract
Cellular and humoral constituents of the immune system differ significantly between children and adults, yet very little is known about the impact of early-life pathogen exposure on this immunologic transition. We examined CD4+ and CD8+ T cell subsets defined by CCR7 and CD45RA expression in two longitudinal pediatric cohorts experiencing divergent levels of pathogen burden. Using multiparameter flow cytometry, along with serological, cytokine, and transcriptomic data, we show that cumulative pathogen burden promotes the development of atypical CD8dim T cells with an innate-like profile (Granzyme Bhi, IFNγlow, TNFαlow, PLFZhi, ID2hi, IKZF2hi) in contrast to age-matched children residing in a low pathogen–exposure area who display a more conventional CD8bright profile (IFNγ+, TNFα+, CCL4+). Furthermore, these unconventional T cells had stunted proliferation, distinct transcriptional programs, and impaired T cell receptor signaling and were enriched in hallmark TNFα, NF-κB, and IL-6 gene signaling pathways, reminiscent of NK cells and type-1 innate lymphoid cells. Our findings suggest that these unconventional CD8dim T cells arise in a very particular immunological context and may provide a deeper understanding of the heterogeneity in human immune responses.
Authors
Yves T. Falanga, Michela Frascoli, Yasin Kaymaz, Catherine Forconi, John Michael Ong’echa, Jeffrey A. Bailey, Leslie J. Berg, Ann M. Moormann
Abstract
BACKGROUND. Both seasonal and novel avian influenza viruses can result in severe infections requiring hospitalization. Anti-influenza antibodies (Abs) with Fc-mediated effector functions, such as Ab-dependent cellular cytotoxicity (ADCC), are of growing interest in control of influenza but have not previously been studied during severe human infections. As such, the objective of this study was to examine Fc-mediated Ab functions in humans hospitalized with influenza infection. METHODS. Serum Ab response was studied in subjects hospitalized with either pandemic H7N9 avian influenza virus in China (n = 18) or circulating seasonal influenza viruses in Melbourne, Australia (n = 16). Recombinant soluble Fc receptor dimer ELISAs, natural killer (NK) cell activation assays, and Ab-dependent killing assays with influenza-infected target cells were used to assess the Fc functionality of anti-influenza hemagglutinin (HA) Abs during severe human influenza infection. RESULTS. We found that the peak generation of Fc functional HA Abs preceded that of neutralizing Abs for both severe H7N9 and seasonal influenza infections. Subjects who succumbed to complications of H7N9 infection demonstrated reduced HA-specific Fc receptor–binding Abs (in magnitude and breadth) immediately prior to death compared with those who survived. Subjects who recovered from H7N9 and severe seasonal influenza infections demonstrated increased Fc receptor–binding Abs not only against the homologous infecting strain but against HAs from different influenza A subtypes. CONCLUSION. Collectively, survivors of severe influenza infection rapidly generate a functional Ab response capable of mediating ADCC against divergent influenza viruses. Broadly binding HA Abs with Fc-mediated functions may be a useful component of protective immunity to severe influenza infection. FUNDING. The National Health and Medical Research Council ([NHMRC] grants 1023294, 1041832, and 1071916), the Australian Department of Health, and the joint University of Melbourne/Fudan University International Research and Research Training Fund provided funding for this study.
Authors
Hillary A. Vanderven, Lu Liu, Fernanda Ana-Sosa-Batiz, Thi H.O. Nguyen, Yanmin Wan, Bruce Wines, P. Mark Hogarth, Danielle Tilmanis, Arnold Reynaldi, Matthew S. Parsons, Aeron C. Hurt, Miles P. Davenport, Tom Kotsimbos, Allen C. Cheng, Katherine Kedzierska, Xiaoyan Zhang, Jianqing Xu, Stephen J. Kent
Abstract
Human cytomegalovirus (HCMV) is the most common congenital infection and a known cause of microcephaly, sensorineural hearing loss, and cognitive impairment among newborns worldwide. Natural maternal HCMV immunity reduces the incidence of congenital infection, but does not prevent the disease altogether. We employed a nonhuman primate model of congenital CMV infection to investigate the ability of preexisting antibodies to protect against placental CMV transmission in the setting of primary maternal infection and subsequent viremia, which is required for placental virus exposure. Pregnant, CD4+ T cell–depleted, rhesus CMV–seronegative (RhCMV-seronegative) rhesus monkeys were treated with either standardly produced hyperimmune globulin (HIG) from RhCMV-seropositive macaques or dose-optimized, potently RhCMV-neutralizing HIG prior to intravenous challenge with an RhCMV mixture. HIG passive infusion provided complete protection against fetal loss in both groups. The dose-optimized, RhCMV-neutralizing HIG additionally inhibited placental transmission of RhCMV and reduced viral replication and diversity. Our findings suggest that the presence of durable and potently neutralizing antibodies at the time of primary infection can prevent transmission of systemically replicating maternal RhCMV to the developing fetus, and therefore should be a primary target of vaccines to eliminate this neonatal infection.
Authors
Cody S. Nelson, Diana Vera Cruz, Dollnovan Tran, Kristy M. Bialas, Lisa Stamper, Huali Wu, Margaret Gilbert, Robert Blair, Xavier Alvarez, Hannah Itell, Meng Chen, Ashlesha Deshpande, Flavia Chiuppesi, Felix Wussow, Don J. Diamond, Nathan Vandergrift, Mark R. Walter, Peter A. Barry, Michael Cohen-Wolkowiez, Katia Koelle, Amitinder Kaur, Sallie R. Permar
Abstract
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.
Authors
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
Abstract
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.
Authors
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
Abstract
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.
Authors
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
Abstract
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
Authors
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
Abstract
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.
Authors
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.
Abstract
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.
Authors
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
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