Virology
Abstract
Human endogenous retroviruses (HERVs) are ancestral viral relics that constitute nearly 8% of the human genome. Although normally silenced, the most recently integrated provirus HERV-K (HML-2) can be reactivated in certain cancers. Here, we report pathological expression of HML-2 in malignant gliomas in both cerebrospinal fluid and tumor tissue that was associated with a cancer stem cell phenotype and poor outcomes. Using single-cell RNA-Seq, we identified glioblastoma cellular populations with elevated HML-2 transcripts in neural progenitor–like cells (NPC-like) that drive cellular plasticity. Using CRISPR interference, we demonstrate that HML-2 critically maintained glioblastoma stemness and tumorigenesis in both glioblastoma neurospheres and intracranial orthotopic murine models. Additionally, we demonstrate that HML-2 critically regulated embryonic stem cell programs in NPC-derived astroglia and altered their 3D cellular morphology by activating the nuclear transcription factor OCT4, which binds to an HML-2–specific long-terminal repeat (LTR5Hs). Moreover, we discovered that some glioblastoma cells formed immature retroviral virions, and inhibiting HML-2 expression with antiretroviral drugs reduced reverse transcriptase activity in the extracellular compartment, tumor viability, and pluripotency. Our results suggest that HML-2 fundamentally contributes to the glioblastoma stem cell niche. Because persistence of glioblastoma stem cells is considered responsible for treatment resistance and recurrence, HML-2 may serve as a unique therapeutic target.
Authors
Ashish H. Shah, Sarah R. Rivas, Tara T. Doucet-O’Hare, Vaidya Govindarajan, Catherine DeMarino, Tongguang Wang, Leonel Ampie, Yong Zhang, Yeshavanth Kumar Banasavadi-Siddegowda, Stuart Walbridge, Dragan Maric, Marta Garcia-Montojo, Robert K. Suter, Myoung-Hwa Lee, Kareem A. Zaghloul, Joseph Steiner, Abdel G. Elkahloun, Jay Chandar, Deepa Seetharam, Jelisah Desgraves, Wenxue Li, Kory Johnson, Michael E. Ivan, Ricardo J. Komotar, Mark R. Gilbert, John D. Heiss, Avindra Nath
An allosteric inhibitor of sirtuin 2 deacetylase activity exhibits broad-spectrum antiviral activity
Abstract
Most drugs used to treat viral disease target a virus-coded product. They inhibit a single virus or virus family, and the pathogen can readily evolve resistance. Host-targeted antivirals can overcome these limitations. The broad-spectrum activity achieved by host targeting can be especially useful in combating emerging viruses and for treatment of diseases caused by multiple viral pathogens, such as opportunistic agents in immunosuppressed patients. We have developed a family of compounds that modulate sirtuin 2, an NAD+-dependent deacylase, and now report the properties of a member of that family, FLS-359. Biochemical and x-ray structural studies show that the drug binds to sirtuin 2 and allosterically inhibits its deacetylase activity. FLS-359 inhibits the growth of RNA and DNA viruses, including members of the coronavirus, orthomyxovirus, flavivirus, hepadnavirus, and herpesvirus families. FLS-359 acts at multiple levels to antagonize cytomegalovirus replication in fibroblasts, causing modest reductions in viral RNAs and DNA, together with a much greater reduction in infectious progeny, and it exhibits antiviral activity in humanized mouse models of infection. Our results highlight the potential of sirtuin 2 inhibitors as broad-spectrum antivirals and set the stage for further understanding of how host epigenetic mechanisms impact the growth and spread of viral pathogens.
Authors
Kathryn L. Roche, Stacy Remiszewski, Matthew J. Todd, John L. Kulp III, Liudi Tang, Alison V. Welsh, Ashley P. Barry, Chandrav De, William W. Reiley, Angela Wahl, J. Victor Garcia, Micah A. Luftig, Thomas Shenk, James R. Tonra, Eain A. Murphy, Lillian W. Chiang
Abstract
HSV-2 coinfection is associated with increased HIV-1 viral loads and expanded tissue reservoirs, but the mechanisms are not well-defined. HSV-2 recurrences result in an influx of activated CD4+ T cells to sites of viral replication and an increase in activated CD4+ T cells in peripheral blood. We hypothesized that HSV-2 induces changes in these cells that facilitate HIV-1 reactivation and replication and tested this hypothesis in human CD4+ T cells and 2D10 cells, a model of HIV-1 latency. HSV-2 promoted latency reversal in HSV-2 infected and bystander 2D10 cells. Bulk and single-cell RNA sequencing studies of activated primary human CD4+ T cells identified decreased expression of HIV-1 restriction factors and increased expression of transcripts including MALAT1 that could drive HIV replication in both the HSV-2-infected and bystander cells. Transfection of 2D10 cells with VP16, an HSV-2 protein that regulates transcription, significantly upregulated MALAT1 expression, decreased trimethylation of lysine 27 on histone H3 protein, and triggered HIV latency reversal. Knockout of MALAT1 from 2D10 cells abrogated the response to VP16 and reduced the response to HSV-2 infection. These results demonstrate that HSV-2 contributes to HIV-1 reactivation through diverse mechanisms including upregulation of MALAT1 to release epigenetic silencing.
Authors
Carl A. Pierce, Lip Nam Loh, Holly R. Steach, Natalia Cheshenko, Paula Preston-Hurlburt, Fengrui Zhang, Stephanie Stransky, Leah Kravets, Simone Sidoli, William M. Philbrick, Michel N. Nassar, Smita Krishnaswamy, Kevan C. Herold, Betsy C. Herold
Abstract
Authors
Brooke D. Kennedy, Jana Blazkova, Jesse S. Justement, Victoria Shi, M. Ali Rai, Maegan R. Manning, Lauren Praiss, Kathleen Gittens, Paul A. Wender, Sean Patro, Xiaolin Wu, Susan Moir, Tae-Wook Chun
Abstract
The focus of hepatitis B functional cure, defined as sustained loss of hepatitis B surface antigen (HBsAg) and HBV DNA from blood, is on eliminating or silencing the intranuclear template for HBV replication, covalently closed circular DNA (cccDNA). However, HBsAg also derives from HBV DNA integrated into the host genome (iDNA). Little is known about the contribution of iDNA to circulating HBsAg with current therapeutics. We applied a multiplex ddPCR assay to demonstrate that iDNA is responsible for maintaining HBsAg quantities in some individuals. Using paired bulk liver tissue from 16 HIV/HBV coinfected persons on nucleos(t)ide analogue (NUC) therapy, we demonstrate that people with larger HBsAg declines between biopsies derive HBsAg from cccDNA whereas people with stable HBsAg levels derive predominantly from iDNA. We applied our assay to individual hepatocytes in paired tissues from three people and demonstrated that the individual with significant HBsAg decline had a commensurate loss of infected cells with transcriptionally active cccDNA, while individuals without HBsAg decline had stable or increasing numbers of cells producing HBsAg from iDNA. We demonstrate that while NUC therapy may be effective at controlling cccDNA replication and transcription, innovative treatments are required to address iDNA transcription that sustains HBsAg production.
Authors
Tanner Grudda, Hyon S. Hwang, Maraake Taddese, Jeffrey Quinn, Mark S. Sulkowski, Richard K. Sterling, Ashwin Balagopal, Chloe L. Thio
Abstract
A prophylactic hepatitis C virus (HCV) vaccine that elicits neutralizing antibodies could be key to HCV eradication. However, the genetic and antigenic properties of HCV envelope (E1E2) proteins capable of inducing anti-HCV broadly neutralizing antibodies (bNAbs) in humans have not been defined. Here, we investigated the development of bNAbs in longitudinal plasma of HCV-infected persons with persistent infection or spontaneous clearance of multiple reinfections. By measuring plasma antibody neutralization of a heterologous virus panel, we found that the breadth and potency of the antibody response increased upon exposure to multiple genetically distinct infections and with longer duration of viremia. Greater genetic divergence between infecting strains was not associated with enhanced neutralizing breadth. Rather, repeated exposure to antigenically-related, antibody sensitive E1E2s was associated with potent bNAb induction. These data reveal that a prime-boost vaccine strategy with genetically distinct, antibody sensitive viruses is a promising approach to induce potent bNAbs in humans.
Authors
Nicole Frumento, Alexis Figueroa, Tingchang Wang, Muhammad Nauman Zahid, Shuyi Wang, Guido Massaccesi, Georgia Stavrakis, James E. Crowe, Jr., Andrew I. Flyak, Hongkai Ji, Stuart C. Ray, George Shaw, Andrea L Cox, Justin R. Bailey
Abstract
The protective human antibody response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus focuses on the spike (S) protein which decorates the virion surface and mediates cell binding and entry. Most SARS-CoV-2 protective antibodies target the receptor-binding domain or a single dominant epitope (‘supersite’) on the N terminal domain (NTD). Here, using the single B cell technology LIBRA-seq, we isolated a large panel of NTD-reactive and SARS-CoV-2 neutralizing antibodies from an individual who had recovered from COVID-19. We found that neutralizing antibodies to the NTD supersite commonly are encoded by the IGHV1-24 gene, forming a genetic cluster that represents a public B cell clonotype. However, we also discovered a rare human antibody, COV2-3434, that recognizes a site of vulnerability on the SARS-CoV-2 S protein in the trimer interface and possesses a distinct class of functional activity. COV2-3434 disrupted the integrity of S protein trimers, inhibited cell-to-cell spread of virus in culture, and conferred protection in human ACE2 transgenic mice against SARS-CoV-2 challenge. This study provides insight about antibody targeting of the S protein trimer interface region, suggesting this region may be a site of virus vulnerability.
Authors
Naveenchandra Suryadevara, Andrea R. Shiakolas, Laura A. VanBlargan, Elad Binshtein, Rita E. Chen, James Brett Case, Kevin J. Kramer, Erica C. Armstrong, Luke Myers, Andrew Trivette, Christopher Gainza, Rachel S. Nargi, Christopher N. Selverian, Edgar Davidson, Benjamin J. Doranz, Summer M. Diaz, Laura S Handal, Robert H. Carnahan, Michael S. Diamond, Ivelin S. Georgiev, James E. Crowe Jr.
Abstract
BACKGROUND. Cytomegalovirus (CMV) is the most common intrauterine infection, leading to infant brain damage. Prognostic assessment of CMV-infected fetuses has remained an ongoing challenge in prenatal care, in the absence of established prenatal biomarkers of congenital CMV (cCMV) infection severity. We aimed to identify prognostic biomarkers of cCMV-related fetal brain injury. METHODS. Global proteome analysis was performed in mid-gestation amniotic fluid samples, comparing fetuses with severe cCMV to asymptomatic CMV-infected fetuses. The levels of selected differentially-excreted proteins were further determined by specific immunoassays. RESULTS. Employing unbiased proteome analysis in a discovery cohort, we identified amniotic fluid proteins related to inflammation and neurological disease pathways, which demonstrated distinct abundance in fetuses with severe cCMV. Amniotic fluid levels of two of these proteins - the immunomodulatory proteins chemerin and galectin-3-binding-protein - were highly predictive of the severity of cCMV in an independent validation cohort, differentiating between fetuses with severe (N=17) and asymptomatic (N=26) cCMV, with 100-93.8% positive predictive value, and 92.9-92.6% negative predictive value (for chemerin - galectin-3-binding-protein, respectively). CONCLUSION. Analysis of chemerin and galectin-3-binding-protein in mid-gestation amniotic fluids could be employed in the clinical setting to profoundly improve the prognostic assessment of CMV-infected fetuses. TRIAL REGISTRATION. NA FUNDING. Israel Science Foundation; Research Fund - Hadassah Medical Organization.
Authors
Olesya Vorontsov, Lorinne Levitt, Daniele Lilleri, Gilad W. Vainer, Orit Caplan, Licita Schreiber, Alessia Arossa, Arsenio Spinillo, Milena Furione, Or Alfi, Esther Oiknine-Djian, Meital Kupervaser, Yuval Nevo, Sharona Elgavish, Moran Yassour, Maurizio Zavattoni, Tali Bdolah-Abram, Fausto Baldanti, Miriam Geal-Dor, Zichria Zakay-Rones, Nili Yanai, Simcha Yagel, Amos Panet, Dana G. Wolf
Abstract
BACKGROUND. It is unclear whether the level of serum hepatitis B virus (HBV) DNA at baseline impacts the on-treatment risk of hepatocellular carcinoma (HCC) in HBeAg positive, non-cirrhotic patients with chronic hepatitis B (CHB). METHODS. We conducted a multicenter cohort study including 2,073 entecavir- or tenofovir-treated, HBeAg-positive, non-cirrhotic, adult CHB patients with baseline HBV DNA levels ≥5.00 log10 IU/mL at three centers in Korea between January 2007 and December 2016. We evaluated the on-treatment incidence rate of HCC by baseline HBV DNA levels. RESULTS. During a median 5.7 years of continuous antiviral treatment, 47 patients developed HCC (0.39 per 100 person-years). By Kaplan–Meier analysis, HCC risk was the lowest in those with baseline HBV DNA levels ≥8.00 log10 IU/mL, increased incrementally with decreasing viral load, and the highest with HBV DNA levels 5.00–5.99 log10 IU/mL (P<0.001). By multivariable analysis, baseline HBV DNA level was an independent factor that was inversely associated with HCC risk. Compared with HBV DNA ≥8.00 log10 IU/mL, the adjusted hazard ratios for HCC risk with HBV DNA 7.00–7.99 log10 IU/mL, 6.00–6.99 log10 IU/mL, and 5.00–5.99 log10 IU/mL were 2.48 (P=0.03), 3.69 (P=0.002), and 6.10 (P<0.001), respectively. CONCLUSION. On-treatment HCC risk increased incrementally with decreasing baseline HBV DNA levels in the range of ≥5.00 log10 IU/mL in HBeAg-positive, non-cirrhotic, adult patients with CHB. Early initiation of antiviral treatment with a high viral load (≥8.00 log10 IU/mL) may maintain the lowest risk of HCC in those patients. FUNDING. Korean Government.
Authors
Won-Mook Choi, Gi-Ae Kim, Jonggi Choi, Seungbong Han, Young-Suk Lim
Abstract
Replication of SARS-CoV-2 in human population is defined by distributions of mutants that are present at different frequencies within the infected host, and can be detected by ultra-deep sequencing techniques. In this study, we have examined the SARS-CoV-2 mutant spectra of amplicons from the spike (S)-coding region of five nasopharyngeal isolates derived from vaccine-breakthrough patients. Interestingly, all patients became infected with the Alpha variant but amino acid substitutions that correspond to the Delta Plus, Iota and Omicron variants were present in the mutant spectra of the resident virus. Deep sequencing analysis of SARS-CoV-2 from vaccine-breakthrough patients revealed a rich reservoir of mutant types, and may also inform of tolerated substitutions that can be represented in epidemiological dominant variants.
Authors
Brenda Martínez-González, Lucía Vázquez-Sirvent, María E. Soria, Pablo Mínguez, Llanos Salar-Vidal, Carlos García-Crespo, Isabel Gallego, Ana Ávila, Carlos Llorens, Beatriz Soriano, Ricardo Ramos-Ruiz, Jaime Esteban, Ricardo Fernandez-Roblas, Ignacio Gadea, Carmen Ayuso, Javier Ruiz-Hornillos, Concepción Pérez-Jorge, Esteban Domingo, Celia Perales
No posts were found with this tag.
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)