Fang Yun Lim, Soo-Young Kim, Karisma N. Kulkarni, Rachel L. Blazevic, Louise E. Kimball, Hannah G. Lea, Amanda J. Haack, Maia S. Gower, Terry Stevens-Ayers, Lea M. Starita, Michael Boeckh, Ollivier Hyrien, Joshua T. Schiffer, Ashleigh B. Theberge, Alpana Waghmare
BACKGROUND. Disease due to dengue viruses is a growing global health threat, causing 100-400 million cases annually. An ideal dengue vaccine should demonstrate durable protection against all four serotypes in phase 3 efficacy trials, however the lack of circulating serotypes may lead to incomplete efficacy data. Controlled human infection models help down select vaccine candidates and supply critical data to supplement efficacy trials. We evaluated the efficacy of a leading live attenuated tetravalent dengue vaccine candidate, TV005, against infection with a newly established dengue serotype 3 or an established serotype 2 challenge virus. METHODS. Two randomized controlled clinical trials were performed. In study 1, 42 subjects received TV005 or placebo (n = 21 each) and six months later all were challenged with dengue 2 virus (DEN2Δ30) at a dose of 103 PFU. In study 2, 23 subjects received TV005, 20 subjects received placebo and six months later all were challenged with 104 PFU dengue 3 virus (DEN3Δ30). Subjects were closely monitored for safety, viremia, and immunologic responses. Infection, measured by post-challenge viremia and by occurrence of rash and neutropenia, were the primary endpoints. Secondary endpoints included safety, immunologic, and virologic profiles following vaccination with TV005 and subsequent DENV2 or DENV3 challenge strains. RESULTS. TV005 was well tolerated and protected all vaccinated volunteers from viremia with DENV2 or 3 (none infected in either group). Placebo recipients had viremia post-challenge (100% in study 1, 85% in study 2) and all experienced rash following challenge with either serotype. CONCLUSIONS. TV005 is a leading tetravalent dengue vaccine candidate which fully protects against infection with DENV2 and DENV3 in an established controlled human infection model. CLINICAL TRIALS REGISTRATION NUMBERS. NCT02317900 and NCT02873260.
Kristen K. Pierce, Anna P. Durbin, Mary-Claire Walsh, Marya Carmolli, Beulah P. Sabundayo, Dorothy M. Dickson, Sean A. Diehl, Stephen S. Whitehead, Beth D. Kirkpatrick
Ruangang Pan, David K. Meyerholz, Stanley Perlman
Targeted metagenomic sequencing is an emerging strategy to survey disease- specific microbiome biomarkers for clinical diagnosis and prognosis. However, this approach often yields inconsistent or conflicting results due to inadequate study power and sequencing bias. We introduce Taxa4Meta, a bioinformatics pipeline explicitly designed to compensate for technical and demographic bias. We designed and validated Taxa4Meta for accurate taxonomic profiling of 16S rRNA amplicon data acquired from different sequencing strategies. Taxa4Meta offers significant potential in identifying clinical dysbiotic features that can reliably predict human disease, validated comprehensively via re-analysis of individual patient 16S datasets. We leveraged the power of Taxa4Meta's pan-microbiome profiling to generate 16S-based classifiers that exhibited excellent utility for stratification of diarrheal patients with Clostridioides difficile infection, irritable bowel syndrome or inflammatory bowel diseases, which represent common misdiagnoses and pose significant challenges for clinical management. We believe that Taxa4Meta represents a new "best practices" approach to individual microbiome surveys that can be used to define gut dysbiosis at a population-scale level.
Qinglong Wu, Shyam Badu, Sik Yu So, Todd J. Treangen, Tor C. Savidge
Virophagy, the selective autophagosomal engulfment and lysosomal degradation of viral components, is crucial for neuronal cell survival and antiviral immunity. However, the mechanisms leading to viral antigen recognition and capture by autophagic machinery remain poorly understood. Here, we identified cyclin-dependent kinase-like 5 (CDKL5), known to function in neurodevelopment, as an essential regulator of virophagy. Loss of function mutations in CDKL5 are associated with a severe neurodevelopmental encephalopathy. We found deletion of CDKL5 or expression of a clinically-relevant pathogenic mutant of CDKL5 reduced virophagy of Sindbis virus (SINV), a neurotropic RNA virus, and increased intracellular accumulation of SINV capsid protein aggregates and cellular cytotoxicity. CDKL5 knockout mice displayed increased viral antigen accumulation and neuronal cell death after SINV infection and enhanced lethality after infection with several neurotropic viruses. Mechanistic studies demonstrated that CDKL5 directly binds the canonical selective autophagy receptor p62 and phosphorylates p62 at T269/S272 to promote its interaction with viral capsid aggregates. We found that CDKL5-mediated phosphorylation of p62 facilitated the formation of large p62 inclusion bodies that captured viral capsids to initiate capsid targeting to autophagic machinery. Overall, these findings identify a cell-autonomous innate immune mechanism for autophagy activation to clear intracellular toxic viral protein aggregates during infection.
Josephine W. Thinwa, Zhongju Zou, Emily Parks, Salwa Sebti, Kelvin K. Hui, Yongjie Wei, Mohammad Goodarzi, Vibha Singh, Greg Urquhart, Jenna L. Jewell, Julie K. Pfeiffer, Beth Levine, Tiffany A. Reese, Michael U. Shiloh
The endothelium plays a critical role in the host response to infection, and has been a focus of investigation in sepsis. While it is appreciated that intravascular thrombus formation, severe inflammation, and loss of endothelial integrity impair tissue oxygenation during sepsis, the precise molecular mechanisms that lead to endothelial injury remain poorly understood. We demonstrate herein that endothelial ADAM10 is essential for the pathogenesis of Staphylococcus aureus sepsis, contributing to a-toxin (Hla)-mediated microvascular thrombus formation and lethality. As ADAM10 is essential for endothelial development and homeostasis, we examined whether other major human sepsis pathogens also rely on ADAM10-dependent pathways in pathogenesis. Mice harboring an endothelial-specific knockout of ADAM10 are protected against lethal Pseudomonas aeruginosa and Streptococcus pneumoniae sepsis, yet remain fully susceptible to Group B Streptococci and Candida albicans sepsis. These studies illustrate a previously unknown role for ADAM10 in sepsis-associated endothelial injury, and suggest that understanding pathogen-specific divergent host pathways in sepsis may enable more precise targeting of disease.
Danielle N. Alfano, Mark J. Miller, Juliane Bubeck Wardenburg
The development of highly effective malaria vaccines and improvement of drug-treatment protocols to boost antiparasitic immunity are critical for malaria elimination. However, the rapid establishment of parasite-specific immune regulatory networks following exposure to malaria parasites hampers these efforts. Here, we identified stimulator of interferon genes (STING) as a critical mediator of type I interferon production by CD4+ T cells during blood-stage Plasmodium falciparum infection. The activation of STING in CD4+ T cells by cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) stimulated IFNB gene transcription, which promoted development of IL-10– and IFN-γ–coproducing CD4+ T (type I regulatory [Tr1]) cells. The critical role for type I IFN signaling for Tr1 cell development was confirmed in vivo using a preclinical malaria model. CD4+ T cell sensitivity to STING phosphorylation was increased in healthy volunteers following P. falciparum infection, particularly in Tr1 cells. These findings identified STING expressed by CD4+ T cells as an important mediator of type I IFN production and Tr1 cell development and activation during malaria.
Yulin Wang, Fabian De Labastida Rivera, Chelsea L. Edwards, Teija C.M. Frame, Jessica A. Engel, Luzia Bukali, Jinrui Na, Susanna S. Ng, Dillon Corvino, Marcela Montes de Oca, Patrick T. Bunn, Megan S.F. Soon, Dean Andrew, Jessica R. Loughland, Jia Zhang, Fiona H. Amante, Bridget E. Barber, James S. McCarthy, J. Alejandro Lopez, Michelle J. Boyle, Christian R. Engwerda
Prashant Rai, Martin Sharpe, Charan K. Ganta, Paul J. Baker, Katrin D. Mayer-Barber, Brian E. Fee, Gregory A. Taylor, Michael B. Fessler
Christoph Strumann, Otavio T. Ranzani, Jeanne Moor, Reinhard Berner, Nicole Toepfner, Cho-Ming Chao, Matthias B. Moor
Biofilms are structured communities of microbial cells embedded in a self-produced matrix of extracellular polymeric substances. Biofilms are associated with many health issues in humans, including chronic wound infections and tooth decay. Current antimicrobials are often incapable of disrupting the polymeric biofilm matrix and reaching the bacteria within. Alternative approaches are needed. Here, we describe a unique structure of dextran coated gold in a gold cage nanoparticle that enables photoacoustic and photothermal properties for biofilm detection and treatment. Activation of these nanoparticles with a near infrared laser can selectively detect and kill biofilm bacteria with precise spatial control and in a short timeframe. We observe a strong biocidal effect against both Streptococcus mutans and Staphylococcus aureus biofilms in mouse models of oral plaque and wound infections respectively. These effects were over 100 times greater than that seen with chlorhexidine, a conventional antimicrobial agent. Moreover, this approach did not adversely affect surrounding tissues. We conclude that photothermal ablation using theranostic nanoparticles is a rapid, precise, and non-toxic method to detect and treat biofilm-associated infections.
Maryam Hajfathalian, Christiaan R. de Vries, Jessica C. Hsu, Ahmad Amirshaghaghi, Yuxi C. Dong, Zhi Ren, Yuan Liu, Yue Huang, Yong Li, Simon A.B. Knight, Pallavi Jonnalagadda, Aimen Zlitni, Elizabeth A. Grice, Paul L. Bollyky, Hyun Koo, David P. Cormode
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