Diabetes mellitus (DM) is highly comorbid with severe dengue diseases; however, the underlying mechanisms are unclear. DM patients display a 1.61-fold increased risk of developing dengue hemorrhagic fever. In search of host factors involved in DENV infection, this study utilizes high glucose (HG) treatment and shows that HG increases viral protein expression and virion release but has no effects on the early stages of viral infection. Following HG stimulation, DEN-Luc-transfected assay and cellular replicon-based assay display increased viral translation, while using the glucose uptake inhibitor phloretin blocks this effect. HG treatment increases the translational factor poly(A)-binding protein (PABP) in a glucose transporter-associated PI3K/AKT-regulated manner. Silencing PABP significantly decreases HG-prompted virion production. HG enhances the formation of the PABP-eIF4G complex, which is regulated by protein-disulfide isomerase. Hyperglycemia increases PABP expression, mortality, viral protein expression, and viral loads in streptozotocin-induced DM mice. Overall, hyperglycemic stress facilitates DENV infection by strengthening PABP-mediated viral translation.
Ting-Jing Shen, Chia-Ling Chen, Tsung-Ting Tsai, Ming-Kai Jhan, Chyi-Huey Bai, Yu-Chun Yen, Ching-Wen Tsai, Cheng-Yi Lee, Po-Chun Tseng, Chia-Yi Yu, Chiou-Feng Lin
Celiac disease is an immune-mediated intestinal disorder that results from loss of oral tolerance (LOT) to dietary gluten. Reovirus elicits inflammatory Th1 cells and suppresses Treg responses to dietary antigen in a strain-dependent manner. Strain type 1 Lang (T1L) breaks oral tolerance, while strain type 3 Dearing reassortant virus (T3D-RV) does not. We discovered that intestinal infection by T1L in mice leads to the recruitment and activation of NK cells in mesenteric lymph nodes (MLNs) in a type I IFN–dependent manner. Once activated following infection, NK cells produce type II IFN and contribute to IFN-stimulated gene expression in the MLNs, which in turn induces inflammatory DC and T cell responses. Immune depletion of NK cells impairs T1L-induced LOT to newly introduced food antigen. These studies indicate that NK cells modulate the response to dietary antigen in the presence of a viral infection.
Pamela H. Brigleb, Elaine Kouame, Kay L. Fiske, Gwen M. Taylor, Kelly Urbanek, Luzmariel Medina Sanchez, Reinhard Hinterleitner, Bana Jabri, Terence S. Dermody
Long COVID, a type of Post-Acute Sequelae of SARS-CoV-2 (PASC), has been associated with sustained elevated levels of immune activation and inflammation. However, the mechanisms that drive this inflammation remain unknown. Inflammation during acute Coronavirus Disease 2019 could be exacerbated by microbial translocation (from gut and/or lung) to blood. Whether microbial translocation contributes to inflammation during PASC is unknown. We did not observe a significant elevation in plasma markers of bacterial translocation during PASC. However, we observed higher levels of fungal translocation – measured as β-glucan, a fungal cell wall polysaccharide – in the plasma of individuals experiencing PASC compared to those without PASC or SARS-CoV-2 negative controls. The higher β-glucan correlated with higher inflammation and elevated levels of host metabolites involved in activating N-Methyl-D-aspartate receptors (such as metabolites within the tryptophan catabolism pathway) with established neuro-toxic properties. Mechanistically, β-glucan can directly induce inflammation by binding to myeloid cells (via Dectin-1) and activating Syk/NF-κB signaling. Using a Dectin-1/NF-κB reporter model, we found that plasma from individuals experiencing PASC induced higher NF-κB signaling compared to plasma from negative controls. This higher NF-κB signaling was abrogated by Piceatannol (Syk inhibitor). These data suggest a potential targetable mechanism linking fungal translocation and inflammation during PASC.
Leila B. Giron, Michael J. Peluso, Jianyi Ding, Grace Kenny, Netanel F. Zilberstein, Jane Koshy, Kai Ying Hong, Heather Rasmussen, Gregory E. Miller, Faraz Bishehsari, Robert A. Balk, James N. Moy, Rebecca Hoh, Scott Lu, Aaron R. Goldman, Hsin-Yao Tang, Brandon C. Yee, Ahmed Chenna, John W. Winslow, Christos J. Petropoulos, J. Daniel Kelly, Haimanot Wasse, Jeffrey N. Martin, Qin Liu, Ali Keshavarzian, Alan Landay, Steven G. Deeks, Timothy J. Henrich, Mohamed Abdel-Mohsen
The recent emergence of the SARS-CoV-2 Omicron variant of concern (VOC) containing a heavily mutated spike protein capable of escaping preexisting immunity identifies a continued need for interventional measures. Molnupiravir (MK-4482), an orally administered nucleoside analog, has demonstrated efficacy against earlier SARS-CoV-2 lineages and was recently approved for SARS-CoV-2 infections in high-risk adults. Here we assessed the efficacy of MK-4482 against the earlier Alpha, Beta and Delta VOCs and Omicron in the hamster COVID-19 model. Omicron replication and associated lung disease in vehicle treated hamsters was reduced compared to the earlier VOCs. MK-4482 treatment inhibited virus replication in the lungs of Alpha, Beta and Delta VOC infected hamsters. Importantly, MK-4482 profoundly inhibited virus replication in the upper and lower respiratory tract of hamsters infected with the Omicron VOC. Consistent with its mutagenic mechanism, MK-4482 treatment had a more pronounced inhibitory effect on infectious titers compared to viral RNA genome load. Histopathologic analysis showed that MK-4482 treatment caused a concomitant reduction in the level of lung disease and viral antigen load in infected hamsters across all VOCs examined. Together, our data indicate the potential of MK-4482 as an effective antiviral against known SARS-CoV-2 VOCs, especially Omicron, and likely future SARS-CoV-2 variants.
Kyle Rosenke, Atsushi Okumura, Matthew C. Lewis, Friederike Feldmann, Kimberly Meade-White, William F. Bohler, Amanda J. Griffin, Rebecca Rosenke, Carl Shaia, Michael A. Jarvis, Heinz Feldmann
A major challenge in managing acute viral infections is ameliorating disease when treatment is delayed. Previously, we reported the success of a two-pronged monoclonal antibody (mAb) and antiviral remdesivir therapeutic approach to treat advanced illness in Marburg virus (MARV)-infected rhesus monkeys. Here, we explored the benefit of a similar combination therapy for Sudan ebolavirus (SUDV) infection. Importantly, no licensed anti-SUDV therapeutics currently exist, and infection of rhesus macaques with SUDV results in a rapid disease course similar to MARV with a mean time-to-death of 8.3 days. When initiation of therapy with either remdesivir or a pan ebolavirus mAb cocktail (MBP431) was delayed until 6 days post inoculation (dpi), only 20% of macaques survived. In contrast, when remdesivir and MBP431 treatment were combined beginning 6 dpi, significant protection (80%) was achieved. Our results suggest that combination therapy may be a viable treatment for patients with advanced filovirus disease that warrants further clinical testing in future outbreaks.
Robert W. Cross, Zachary A. Bornholdt, Abhishek N. Prasad, Courtney Woolsey, Viktoriya Borisevich, Krystle N. Agans, Daniel J. Deer, Dafna M. Abelson, Do H. Kim, William S. Shestowsky, Lioudmila A. Campbell, Elaine Bunyan, Joan B. Geisbert, Natalie S. Dobias, Karla A. Fenton, Danielle P. Porter, Larry Zeitlin, Thomas W. Geisbert
Congenital cytomegalovirus (cCMV) infection is the leading infectious cause of neurodevelopmental disorders. However, the neuropathogenesis remains largely elusive due to a lack of informative animal models. In this study, we developed a congenital murine CMV (cMCMV) infection mouse model with high survival rate and long survival period that allowed long-term follow-up study of neurodevelopmental disorders. This model involves in utero intracranial injection and mimics many reported clinical manifestations of cCMV infection in infants, including growth restriction, hearing loss, and impaired cognitive and learning-memory abilities. We observed that abnormalities in MRI/CT neuroimaging were consistent with brain hemorrhage and loss of brain parenchyma, which was confirmed by pathological analysis. Neuropathological findings included ventriculomegaly and cortical atrophy associated with impaired proliferation and migration of neural progenitor cells in the developing brain at both embryonic and postnatal stages. Robust inflammatory responses during infection were shown by elevated inflammatory cytokine levels, leukocyte infiltration, and activation of microglia and astrocytes in the brain. Pathological analyses and CT neuroimaging revealed brain calcifications induced by cMCMV infection and cell death via pyroptosis. Furthermore, antiviral treatment with ganciclovir significantly improved neurological functions and mitigated brain damage as shown by CT neuroimaging. These results demonstrate that this model is suitable for investigation of mechanisms of infection-induced brain damage and long-term studies of neurodevelopmental disorders, including the development of interventions to limit CNS damage associated with cCMV infection.
Yue-Peng Zhou, Meng-Jie Mei, Xian-Zhang Wang, Sheng-Nan Huang, Lin Chen, Ming Zhang, Xin-Yan Li, Hai-Bin Qin, Xiao Dong, Shuang Cheng, Le Wen, Bo Yang, Xue-Fang An, Ao-Di He, Bing Zhang, Wen-Bo Zeng, Xiao-Jun Li, Youming Lu, Hong-Chuang Li, Haidong Li, Wei-Guo Zou, Alec J. Redwood, Simon Rayner, Han Cheng, Michael A. McVoy, Qiyi Tang, William J. Britt, Xin Zhou, Xuan Jiang, Min-Hua Luo
Invariant natural killer T (iNKT) cells are implicated in viral clearance, however their role in HCV infection remains controversial. Here, iNKT cells were studied during different stages of HCV infection. iNKT cells from patients with acute HCV infection and people who inject drugs (PWID) with chronic or spontaneously resolved HCV infection were characterized by flow cytometry. In a longitudinal analysis during acute HCV infection, frequencies of activated CD38+ iNKT cells reproducibly declined in spontaneously resolving patients whereas they were persistently elevated in patients progressing to chronic infection. During the first year of infection, the frequency of activated CD38+ or CD69+ iNKT cells strongly correlated with alanine transaminase levels with particularly pronounced correlations in spontaneously resolving patients. Increased frequencies of activated iNKT cells in chronic HCV infection were confirmed in cross-sectional analyses of PWID with chronic or spontaneously resolved HCV infection, however, no apparent functional differences were observed with various stimulation protocols. Our data suggest that iNKT cells are activated during acute hepatitis C and that activation is sustained in chronic infection. The correlation between the frequency of activated iNKT cells and ALT may point towards a role of iNKT cells in liver damage.
Tina Senff, Christopher Menne, Christine Cosmovici, Lia Laura Lewis-Ximenez, Jasneet Aneja, Ruth Broering, Arthur Y. Kim, Astrid M. Westendorf, Ulf Dittmer, Norbert Scherbaum, Georg M. Lauer, Jörg Timm
Understanding viral rebound in pediatric HIV-1 infection may inform the development of alternatives to lifelong antiretroviral therapy (ART) to achieve viral remission. We thus investigated viral rebound after analytical treatment interruption (ATI) in 10 infant macaques orally infected with SHIV.C.CH505 and treated with long-term ART. Rebound viremia was detected within 7-35 days of ATI in 9/10 animals, with post-treatment control of viremia seen in 5/5 Mamu-A*01+ macaques. Single-genome sequencing revealed initial rebound virus was similar to viral DNA present in CD4+ T cells from blood, rectum, and lymph nodes before ATI. We assessed the earliest sites of viral reactivation immediately following ATI using ImmunoPET imaging. The largest increase in signal that preceded detectable viral RNA in plasma was found in the gastrointestinal (GI) tract, a site with relatively high SHIV RNA/DNA ratios in CD4+ T cells prior to ATI. Thus, the GI tract may be an initial source of rebound virus but as ATI progresses, viral reactivation in other tissues likely contributes to the composition of plasma virus. Our study provides novel insight into the features of viral rebound in pediatric infection and highlights the application of a non-invasive technique to monitor areas of HIV-1 expression in children.
Veronica Obregon-Perko, Katherine M. Bricker, Gloria Mensah, Ferzan Uddin, Laura Rotolo, Daryll Vanover, Yesha Desai, Philip J. Santangelo, Sherrie Jean, Jennifer S. Wood, Fawn C. Connor-Stroud, Stephanie Ehnert, Stella J. Berendam, Shan Liang, Thomas H. Vanderford, Katharine J. Bar, George M. Shaw, Guido Silvestri, Amit Kumar, Genevieve G. Fouda, Sallie R. Permar, Ann Chahroudi
The ectocervix is part of the lower female reproductive tract (FRT), which is susceptible to sexually transmitted infections (STI). Comprehensive knowledge of the phenotypes and T cell receptor (TCR) repertoire of tissue resident memory T cells (TRM) in human FRT is lacking. We have taken single-cell RNA sequencing approaches to simultaneously define gene expression and TCR clonotypes of the human ectocervix. There are significantly more CD8 than CD4 T cells. Unsupervised clustering and trajectory analysis identify distinct populations of CD8 T cells with IFNGhiGZMBlowCD69hiCD103low or IFNGlowGZMBhiCD69medCD103hi phenotypes. Little overlap was seen between their TCR repertoires. Immunofluorescent staining shows that CD103+ CD8 TRM cells preferentially localize in epithelium while CD69+ CD8 TRM distribute evenly in epithelium and stroma. Ex vivo assays indicate up to 14% of cervical CD8 TRM clonotypes are HSV-2 reactive in HSV-2-seropositive persons, reflecting physiologically relevant localization. Our studies identify subgroups of CD8 TRM in the human ectocervix that exhibit distinct expression of antiviral defense and tissue residency markers, anatomic locations, and TCR repertoires that target anatomically relevant viral antigens. Optimization of the location, number, and function of FRT TRM is an important approach for improving host defenses to STI.
Tao Peng, Khamsone Phasouk, Emily Bossard, Alexis Klock, Lei Jin, Kerry J. Laing, Christine Johnston, Noel A. Williams, Julie L. Czartoski, Dana Varon, Annalyssa N. Long, Jason H. Bielas, Thomas M. Snyder, Harlan Robins, David M. Koelle, M Juliana McElrath, Anna Wald, Lawrence Corey, Jia Zhu
Virus-induced respiratory tract infections are a major health burden in childhood, and available treatments are supportive rather than disease modifying. Rhinoviruses (RVs), the cause of approximately 80% of common colds, are detected in nearly half of all infants with bronchiolitis and the majority of children with an asthma exacerbation. Bronchiolitis in early life is a strong risk factor for the development of asthma. Here, we found that RV infection induced the expression of miRNA 122 (miR-122) in mouse lungs and in human airway epithelial cells. In vivo inhibition specifically in the lung reduced neutrophilic inflammation and CXCL2 expression, boosted innate IFN responses, and ameliorated airway hyperreactivity in the absence and in the presence of allergic lung inflammation. Inhibition of miR-122 in the lung increased the levels of suppressor of cytokine signaling 1 (SOCS1), which is an in vitro–validated target of miR-122. Importantly, gene silencing of SOCS1 in vivo completely reversed the protective effects of miR-122 inhibition on RV-induced lung disease. Higher miR-122 expression in nasopharyngeal aspirates was associated with a longer time on oxygen therapy and a higher rate of treatment failure in 87 infants hospitalized with moderately severe bronchiolitis. These results suggest that miR-122 promotes RV-induced lung disease via suppression of its target SOCS1 in vivo. Higher miR-122 expression was associated with worse clinical outcomes, highlighting the potential use of anti-miR-122 oligonucleotides, successfully trialed for treatment of hepatitis C, as potential therapeutics for RV-induced bronchiolitis and asthma exacerbations.
Adam M. Collison, Leon A. Sokulsky, Elizabeth Kepreotes, Ana Pereira de Siqueira, Matthew Morten, Michael R. Edwards, Ross P. Walton, Nathan W. Bartlett, Ming Yang, Thi Hiep Nguyen, Sebastian L. Johnston, Paul S. Foster, Joerg Mattes
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