{"title":"RNF20 dual regulation of MDA5 signaling to maintain immune homeostasis in chickens.","authors":"Jie Wang, Qiuju Liu, Kehui Zhang, Shurui Zhao, Qi Shao, Feiyu Fu, Jingjiao Ma, Zhaofei Wang, Ya-Xian Yan, Hengan Wang, Jianhe Sun, Yuqiang Cheng","doi":"10.1128/jvi.02008-24","DOIUrl":"10.1128/jvi.02008-24","url":null,"abstract":"<p><p>RIG-I and MDA5, known as the RIG-I-like receptors (RLRs), play a pivotal role in inducing antiviral responses to RNA viral infections. While chickens lack RIG-I, they possess a functionally enhanced MDA5 that recognizes pathogens and regulates immunity, underscoring the critical role of MDA5 in maintaining immune homeostasis in chickens. However, the precise mechanisms governing the expression and optimal activation of MDA5 remain unclear. Here, we reveal that the chicken E3 ubiquitin ligase RNF20 is essential for modulating MDA5-mediated innate immune homeostasis. Transcriptome sequencing analysis revealed that RNA viral infection of DF-1 cells significantly upregulated the expression of chicken RNF20. Overexpression of RNF20 markedly suppresses the expression of chicken innate immunity-related genes, while RNF20 knockout leads to immune deficiency both <i>in vivo</i> and <i>in vitro</i>. Mechanistically, RNF20 is located in the nucleus, where it maintains the basic expression and regulates the inducible expression of MDA5 to establish immune defense during the early infection phase. In the late phase, RNF20 translocates to the cytoplasm, where it facilitates the K27- and K48-linked polyubiquitination and subsequent degradation of MDA5, thereby preventing immune overstimulation. Overall, this study establishes RNF20 as an important E3 ubiquitin ligase that maintains chicken innate immune homeostasis.</p><p><strong>Importance: </strong>Chicken MDA5 is an important RNA viral sensor for initiating the antiviral innate immune response. The protein level of MDA5 must be tightly regulated to maintain antiviral innate immune homeostasis. In this study, we demonstrate that the E3 ubiquitin ligase RNF20 precisely regulates MDA5 protein stabilization through nucleoplasmic translocation. Specifically, in uninfected and during early infection, RNF20 regulates MDA5 transcription in the nucleus. While in the late stages of infection, RNF20 translocates out of the nucleus and catalyzes the ubiquitinated degradation of MDA5. Thus, RNF20 is important in regulating chicken antiviral innate immune homeostasis.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0200824"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-25DOI: 10.1128/jvi.01579-24
Jorge F Guerrero, Laraine L Zimdars, James W Bruce, Jordan T Becker, Edward L Evans, Soroosh Torabi, Rob Striker, Scott M Berry, Nathan M Sherer
{"title":"Single-cell delineation of strain-specific HIV-1 Vif activities using dual reporter sensor cells and live cell imaging.","authors":"Jorge F Guerrero, Laraine L Zimdars, James W Bruce, Jordan T Becker, Edward L Evans, Soroosh Torabi, Rob Striker, Scott M Berry, Nathan M Sherer","doi":"10.1128/jvi.01579-24","DOIUrl":"10.1128/jvi.01579-24","url":null,"abstract":"<p><p>Human immunodeficiency virus type 1 (HIV-1) genome diversification is a key determinant of viral evolution and the pathogenesis of HIV/AIDS. Antiretroviral therapy is non-curative, and in the context of monitoring the latent reservoir, precision tools are needed to detect and enumerate HIV-1 genomes as well as to assess their heterogeneity, replication potential, and predict responses to therapy. Current sequencing-based methodologies are often unable to confirm intact genomes and most cell-based reporters provide limited information pertaining to viral fitness. In this study, we describe dual reporter sensor cells (DRSCs), an imaging-based reporter system designed to detect HIV-1 infection and measure several independent attributes of the virus in a single-cell high-content assay. We show that the DRSC assay can be used to measure infection, viral gene activation kinetics, and quantify viral circumvention of host antiviral responses. Using the DRSCs, we confirmed markedly different functional heterogeneity for <i>vif</i> alleles derived from diverse HIV-1 strains and subtypes affecting both rates of APOBEC3G degradation and the cell cycle. Furthermore, the assay allowed for the delineation of virus co-receptor preference (X4- vs R5-tropism) and visualization of virion assembly. Overall, our study illustrates proof-of-principle for a multivariate imaging-based cell-based system capable of detecting HIV-1 and studying viral genetic variability with greater data richness relative to prior available modalities.</p><p><strong>Importance: </strong>Human immunodeficiency virus type 1 (HIV-1) is highly heterogeneous and constantly mutating. These changes drive immune evasion and can cause treatment efforts to fail. Here, we describe the \"dual reporter sensor cell\" (DRSC) assay; a novel imaging-based approach that allows for the detection of HIV-1 infection coupled with a multivariate definition of several independent phenotypic aspects of viral genome activity in a single integrated assay. We validate the DRSC system by studying lab-adapted and patient isolate-derived versions of the viral Vif accessory protein, confirming marked differences in the capacity of diverse <i>vif</i> alleles to mediate downregulation of antiviral APOBEC3G proteins and dysregulate the cell cycle.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0157924"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915839/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-03DOI: 10.1128/jvi.02117-24
Hua Bai, Yueyu Ma, Huitong Qiu, Yang Qi, Yingshuo Huang, Yaxi Guo, Li Sun, Ming Li, Dongliang Fei, Mingxiao Ma, Yuming Liu
{"title":"Chinese sacbrood virus mediates m6A modification to target and suppress the expression of hemolymph maintenance gene AF9, exacerbating bee infections.","authors":"Hua Bai, Yueyu Ma, Huitong Qiu, Yang Qi, Yingshuo Huang, Yaxi Guo, Li Sun, Ming Li, Dongliang Fei, Mingxiao Ma, Yuming Liu","doi":"10.1128/jvi.02117-24","DOIUrl":"10.1128/jvi.02117-24","url":null,"abstract":"<p><p>The Chinese sacbrood virus (CSBV) severely threatens the beekeeping industry, wherein 3- to 5-day-old larvae in the critical differentiation stage are highly susceptible to low levels of CSBV exposure. Once infected, larvae cannot undergo normal pupation, but the pathogenic mechanism remains unclear. Previous studies have shown that m6A modification plays an important regulatory role in larval development during the critical differentiation stage. However, it is unknown whether CSBV infection affects the pupation of honeybee larvae by altering m6A modification. Here, a novel immunoregulatory factor, AF9, was identified in honeybee larvae through combined methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq analysis following CSBV infection. Enzyme-linked immunosorbent assay (ELISA) quantification of m6A methylation in total RNA and MeRIP-qPCR further revealed that CSBV infection of honeybee larvae inhibits the expression of <i>AF9</i> via m6A modification, thereby hindering the host innate immune response and promoting CSBV replication. MeRIP-qPCR was then used to demonstrate that AcMETTL3 targets and modifies <i>AF9</i> mRNA, thereby inhibiting <i>AF9</i> expression. Homology and functional analysis of human-derived <i>AF9</i> (MLLT3) suggested that AF9 exerted a similar effect as MLLT3 on honeybee hemolymph functioning. dsRNA was then fed to silence genes, followed by RNA extraction and expression analysis from hemolymph. Downregulation of <i>AF9</i> expression led to decreased numbers of live cells in the hemolymph of honeybee larvae and a reduction in phenoloxidase activity, thereby inhibiting the host immune response. Finally, an <i>Apis mellifera</i> pupation infection model was constructed to further explore the antiviral activities associated with <i>AmAF9. AmAF9</i> exerted a similarly significant antiviral effect against deformed wing virus (DWV) and acute bee paralysis virus (ABPV) infections in <i>Apis mellifera</i> pupae. These results indicate that CSBV infection promotes overall m6A modification in the host and inhibits the expression of <i>AF9</i> through AcMETTL3 targeting, leading to host immunosuppression and exacerbating honeybee infection. Similarly, <i>AF9</i> is stably expressed in <i>Apis mellifera</i> and exhibits the same antiviral effect, making it a broad-spectrum target in honeybee viruses.</p><p><strong>Importance: </strong>The Chinese sacbrood virus (CSBV) poses a serious threat to the health of <i>Apis cerana</i> colonies, yet its specific pathogenic mechanism remains unclear. This study shows that infection with CSBV can enhance overall m6A modification levels in <i>Apis cerana</i> larvae and suppress the expression of <i>AF9</i> by promoting targeting of AcMETTL3, thereby inhibiting the innate immune response and exacerbating CSBV infection. Further analyses indicated that <i>AF9</i> functions similarly as the mammalian homologous gene <i>MLLT3</i> by maintaining normal functions of hemolym","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0211724"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915840/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143080623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-06DOI: 10.1128/jvi.02242-24
Karla M Viramontes, Melissa N Thone, Jamie-Jean De La Torre, Emily N Neubert, Julia M DeRogatis, Chris Garcia, Monique L Henriquez, Roberto Tinoco
{"title":"Contrasting roles of PSGL-1 and PD-1 in regulating T-cell exhaustion and function during chronic viral infection.","authors":"Karla M Viramontes, Melissa N Thone, Jamie-Jean De La Torre, Emily N Neubert, Julia M DeRogatis, Chris Garcia, Monique L Henriquez, Roberto Tinoco","doi":"10.1128/jvi.02242-24","DOIUrl":"10.1128/jvi.02242-24","url":null,"abstract":"<p><p>Immune checkpoints are critical regulators of T-cell exhaustion, impairing their ability to eliminate antigens present during chronic viral infections. Current immune checkpoint inhibitors (ICIs) used in the clinic aim to reinvigorate exhausted T cells; yet, most patients fail to respond or develop resistance to these therapies, underscoring the need to better understand these immunosuppressive pathways. PSGL-1 (<i>Selplg</i>), a recently discovered immune checkpoint, negatively regulates T-cell function. We investigated the cell-intrinsic effects of PSGL-1, PD-1, and combined deletion on CD8<sup>+</sup> T cells during chronic viral infection. We found that combined PSGL-1 and PD-1 (<i>Selplg<sup>-/-</sup>Pdcd1<sup>-/-</sup></i>) deficiency in CD8<sup>+</sup> T cells increased their frequencies and numbers throughout chronic infection compared to the wild type. This phenotype was primarily driven by PD-1 deficiency. Furthermore, while PD-1 deletion increased virus-specific T-cell frequencies, it was detrimental to their function. Conversely, PSGL-1 deletion improved T-cell function but resulted in lower frequencies and numbers. The primary mechanism behind these differences in cell maintenance was driven by proliferation rather than survival. Combined PSGL-1 and PD-1 deletion resulted in defective T-cell differentiation, driving cells from a progenitor self-renewal state to a more terminal dysfunctional state. These findings suggest that PD-1 and PSGL-1 have distinct, yet complementary, roles in regulating T-cell exhaustion and differentiation during chronic viral infection. Overall, this study provides novel insights into the individual and combined roles of PSGL-1 and PD-1 in CD8<sup>+</sup> T-cell exhaustion. It underscores the potential of targeting these checkpoints in a more dynamic and sequential manner to optimize virus-specific T-cell responses, offering critical perspectives for improving therapeutic strategies aimed at reinvigorating exhausted CD8<sup>+</sup> T cells.IMPORTANCEOur findings provide a comprehensive analysis of how the dual deletion of PD-1 and PSGL-1 impacts the response and function of virus-specific CD8<sup>+</sup> T cells, revealing novel insights into their roles in chronic infection. Notably, our findings show that while PD-1 deletion enhances T-cell frequencies, it paradoxically reduces T-cell functionality. Conversely, PSGL-1 deletion improves T-cell function but reduces their survival. Whereas the combined deletion of PSGL-1 and PD-1 in CD8<sup>+</sup> T cells improved their survival but decreased their function and progenitor-exhausted phenotypes during infection. We believe our study advances the understanding of immune checkpoint regulation in chronic infections and has significant implications for developing more effective immune checkpoint inhibitor (ICI) therapies.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0224224"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915808/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143256009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-11DOI: 10.1128/jvi.01532-24
Julie L Mitchell, Supranee Buranapraditkun, Pierre Gantner, Hiroshi Takata, Kenneth Dietze, Kombo F N'guessan, Justin Pollara, Junsuke Nohara, Roshell Muir, Eugene Kroon, Suteeraporn Pinyakorn, Nicha Tulmethakaan, Sopark Manasnayakorn, Suthat Chottanapund, Pattarawat Thantiworasit, Peeriya Prueksakaew, Nisakorn Ratnaratorn, Suwanna Puttamaswin, Bessara Nuntapinit, Lawrence Fox, Elias K Haddad, Dominic Paquin-Proulx, Praphan Phanuphak, Carlo P Sacdalan, Nittaya Phanuphak, Jintanat Ananworanich, Denise Hsu, Sandhya Vasan, Guido Ferrari, Nicolas Chomont, Lydie Trautmann
{"title":"Activation of CXCR3<sup>+</sup> Tfh cells and B cells in lymph nodes during acute HIV-1 infection correlates with HIV-specific antibody development.","authors":"Julie L Mitchell, Supranee Buranapraditkun, Pierre Gantner, Hiroshi Takata, Kenneth Dietze, Kombo F N'guessan, Justin Pollara, Junsuke Nohara, Roshell Muir, Eugene Kroon, Suteeraporn Pinyakorn, Nicha Tulmethakaan, Sopark Manasnayakorn, Suthat Chottanapund, Pattarawat Thantiworasit, Peeriya Prueksakaew, Nisakorn Ratnaratorn, Suwanna Puttamaswin, Bessara Nuntapinit, Lawrence Fox, Elias K Haddad, Dominic Paquin-Proulx, Praphan Phanuphak, Carlo P Sacdalan, Nittaya Phanuphak, Jintanat Ananworanich, Denise Hsu, Sandhya Vasan, Guido Ferrari, Nicolas Chomont, Lydie Trautmann","doi":"10.1128/jvi.01532-24","DOIUrl":"10.1128/jvi.01532-24","url":null,"abstract":"<p><p>Lymph node T follicular helper (Tfh) cells and germinal center (GC) B cells are critical to generate potent antibodies but are rarely possible to study in humans. To understand how Tfh/GC B-cell interactions during acute HIV-1 infection (AHI) impact the generation of HIV-specific antibodies, we performed a unique cross-sectional analysis of inguinal lymph node biopsies taken prior to antiretroviral therapy (ART) initiation in AHI. Although total Tfh and GC B cell frequencies did not change during AHI, increased frequencies of proliferating Th1-like CXCR3<sup>+</sup> Tfh, CXCR3<sup>+</sup> non-GC B cells, and total CXCR3<sup>+</sup> GC B cells correlated with gp120-specific IgG antibody levels in AHI. Frequencies of proliferating CXCR3<sup>+</sup> Tfh in AHI also correlated with gp120-specific IgG antibody levels after 48 weeks of ART, antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and increased antibody binding to infected cells after ART. Importantly, while beneficial for antibody development, CXCR3<sup>+</sup> Tfh cells were also infected by HIV-1 at higher frequencies than their CXCR3<sup>-</sup> counterparts and may contribute to the initial dissemination of HIV-1 in follicles. Together, these data suggest that activation of CXCR3<sup>+</sup> Tfh cells is associated with induction of the germinal center response and subsequent antibody development, making these cells an important target for future therapeutic interventions.</p><p><strong>Importance: </strong>Early initiation of antiretroviral therapy (ART) is important to limit the seeding of the long-lasting HIV-1 reservoir; however, it also precludes the development of HIV-specific antibodies that can help control the virus if ART is stopped. Antibody development occurs within germinal centers in the lymph node and requires activation of both antigen-specific B cells and T follicular helper cells (Tfh), a specialized CD4<sup>+</sup> cell that provides B cell help. To understand how early ART initiation may prohibit antibody development, we analyzed the frequencies and activation status of Tfh and B cells in lymph node biopsies collected in the different stages of acute HIV-1 infection. Our data suggest that decreased antibody development after early ART initiation may be due to limited germinal center development at the time of treatment and that new interventions that target activation of CXCR3<sup>+</sup> Tfh may be beneficial to increase long-term HIV-specific antibody levels.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0153224"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915809/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143391109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-11DOI: 10.1128/jvi.02213-24
Carolina Stenfeldt, Ian H Fish, Monica Rodriguez-Calzada, Gisselle Medina, Juergen A Richt, Jonathan Arzt
{"title":"Differential mosaicism of recombinant foot-and-mouth disease viruses resulting from heterologous superinfection of cattle.","authors":"Carolina Stenfeldt, Ian H Fish, Monica Rodriguez-Calzada, Gisselle Medina, Juergen A Richt, Jonathan Arzt","doi":"10.1128/jvi.02213-24","DOIUrl":"10.1128/jvi.02213-24","url":null,"abstract":"<p><p>Evidence from both field and experimental studies suggests that recombination is a common feature in the evolution of foot-and-mouth disease virus (FMDV). Recent studies have demonstrated that heterologous superinfection of cattle persistently infected with FMDV leads to rapid generation of inter-serotypic recombinant viruses in the upper respiratory tract mucosa. The current study demonstrates that the order of exposure to FMDV strains A24 Cruzeiro and O1 Manisa substantially influenced the patterns of mosaicism of resultant recombinants. FMDV recombinants were isolated from oropharyngeal fluid samples from 7 of 12 cattle following heterologous superinfection at 21 days post-initial infection. There was no apparent competitive advantage of either parental virus. However, recombinant viruses recovered from six of seven animals had gained, or regained through multiple recombination events, the capsid-coding sequence of FMDV O1 Manisa despite the presence of high titers of neutralizing antibodies against that virus. Additionally, a sub-genomic region of high amino acid diversity, spanning the 3' portion of 3A through 3B, was derived from FMDV A24 in most of the recovered recombinants. Despite the frequent recovery of FMDV recombinants from the upper respiratory tract of superinfected animals, there was no detection of recombinant viruses in blood or lesions in the subset of animals that developed clinical foot-and-mouth disease during superinfection. Overall, these findings confirm the high frequency at which FMDV recombination occurs when persistently infected carrier cattle are exposed to a heterologous virus and reaffirm that superinfection of carriers should be considered as a source of FMDV genetic diversity in endemic regions.IMPORTANCEFoot-and-mouth disease virus (FMDV) is a pathogen of domestic livestock with profound global socioeconomic impacts. FMDV causes a subclinical persistent infection in ruminant hosts, such as cattle, during which the animals may become sequentially infected by heterologous variants of the virus. Our previous works have demonstrated that such superinfections frequently lead to emergence of novel recombinant virus variants in the upper respiratory tracts of infected animals. This current investigation demonstrates that the order in which the animals are exposed to two different viruses substantially influences the structure of resultant recombinant genomes and confirms the frequency at which FMDV recombination occurs following heterologous superinfection of persistently infected FMDV carriers.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0221324"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915824/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143391124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-25DOI: 10.1128/jvi.01922-24
Gavin Golas, Byung S Park, Scott W Wong
{"title":"Glycoproteins gM and gN are indispensable factors for rhesus macaque rhadinovirus replication and spread but can be reconstituted by KSHV chimeras.","authors":"Gavin Golas, Byung S Park, Scott W Wong","doi":"10.1128/jvi.01922-24","DOIUrl":"10.1128/jvi.01922-24","url":null,"abstract":"<p><p>Rhesus macaque rhadinovirus (RRV) is a primate gamma-2 herpesvirus (rhadinovirus) closely related to Kaposi sarcoma-associated herpesvirus (KSHV), the human oncovirus that causes Kaposi sarcoma. Like other herpesviruses, KSHV and RRV encode numerous envelope glycoproteins involved in cell attachment, entry, as well as assembly and release of progeny virions from infected cells. Two glycoproteins postulated to form a complex and reported to be virus-neutralizing targets are glycoproteins M (gM) and N (gN). To investigate gM and gN in rhadinovirus infection, we utilized infectious and pathogenic bacterial artificial chromosomes (BAC). RRV BACmids with nonsense mutations introduced into gM or gN did not yield an infectious virus. However, when gM or gN of RRV were exchanged for gM or gN from KSHV, each of the KSHV-chimeric RRV BACmids restored virus replication and infectious spread. Interestingly, we also discovered that the substitution of KSHVgM into the RRV BACmid was associated with attenuation in viral spread, an effect that was not countered by a double-chimeric virus. In contrast, the substitution of RRV gN into a KSHV BACmid negatively affected the assembly of KSHV, independent of gM/gN complex formation. Therefore, here, we revealed that in KSHV and RRV, gM and gN are interchangeable, contribute to crucial functions for viral assembly and spread, and have evolved in a virus-specific manner. Although more research is needed to define the roles of gM and gN, our work establishes the first glycoprotein-chimeric viruses for KSHV and RRV, which can now be used to corroborate gM/gN as targets for a cancer vaccine.IMPORTANCEKaposi sarcoma (KS) is a human cancer caused by KSHV and is one of the most frequently occurring cancers in HIV/AIDS patients, as well as in regions where KSHV is endemic. In this report, we have constructed and authenticated the first KSHV glycoprotein-encoding chimeric viruses for evaluations in the RRV/rhesus macaque model and have also uncovered fundamental roles for the glycoproteins gM and gN. Our work is significant by successfully bridging the human-specific, species barrier that has previously restricted preclinical evaluations of the KSHV glycoproteins as vaccine targets <i>in vivo</i>. Although there is no KSHV-specific animal model that is widely used, these KSHV-chimeric viruses may be useful as tools to guide future vaccine design and strategy as vaccine candidates progress toward clinical trials.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0192224"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915806/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-05DOI: 10.1128/jvi.01724-24
Rebeca Froes Rocha, Laís D Coimbra, Marina A Fontoura, Guilherme Ribeiro, Giuliana Eboli Sotorilli, Giovanni F Gomes, Alexandre Borin, Jaqueline Felipe, Emily Slowikowski, Wilias Silva Santos Greison, Thiago M Cunha, Pedro Elias Marques, Pedro M M Vieira, Rafael Elias Marques
{"title":"Usutu virus-induced meningoencephalitis in immunocompetent mice is characterized by the recruitment of mononuclear cells and a proinflammatory T helper 1 response.","authors":"Rebeca Froes Rocha, Laís D Coimbra, Marina A Fontoura, Guilherme Ribeiro, Giuliana Eboli Sotorilli, Giovanni F Gomes, Alexandre Borin, Jaqueline Felipe, Emily Slowikowski, Wilias Silva Santos Greison, Thiago M Cunha, Pedro Elias Marques, Pedro M M Vieira, Rafael Elias Marques","doi":"10.1128/jvi.01724-24","DOIUrl":"10.1128/jvi.01724-24","url":null,"abstract":"<p><p>Usutu virus (USUV) is an arbovirus and has emerged as a potential cause of encephalitis in humans and other vertebrates. The increasing detection of USUV in mosquitoes and birds across Africa and Central Europe, along with the lack of specific treatments or vaccines for many encephalitic orthoflaviviruses, underscores the need for focused research. In this study, we developed a USUV infection model in immunocompetent C57BL/6 mice (8-12 weeks old) to characterize disease development and associated inflammatory mechanisms. Mice were intracranially infected with 10<sup>4</sup> PFU of USUV, leading to neurological symptoms such as hunched posture, paralysis, conjunctivitis, and eventual death by day 6 post-infection. Meningeal cell infiltration and microglia activation were most prevalent in mouse brains; however, neuronal loss was not observed at the peak of the disease, which coincided with increased viral load and leukocyte infiltration. The immune response in the brain was marked by the systematic recruitment and activation of macrophages, neutrophils, and T lymphocytes. A noticeable shift was seen in CD4+ T cells toward T helper 1 (Th1) polarization, which corroborates a massive increase in the expression of Th1-associated cytokines and chemokines at the peak of infection, indicative of an augmented proinflammatory state. Additionally, a rise in regulatory T cells was observed, peaking on day 6 post-infection. These findings highlight the dynamic nature of the host response to USUV infection, enhance our understanding of the disease pathogenesis, and address the scarcity of immunocompetent experimental models for the investigation of neglected emerging flaviviruses.IMPORTANCEMosquito-borne viruses, including USUV, are maintained in nature through complex cycles involving arthropod vectors and vertebrate hosts. A comprehensive understanding of USUV biology and host-pathogen interactions is crucial for developing effective treatments, which necessitates reliable experimental models (G. J. Sips, J. Wilschut, and J. M. Smit, Rev Med Virol 22:69-87, 2012, https://doi.org/10.1002/rmv.712; T. C. Pierson and M. S. Diamond, Nat Microbiol 5:796-812, 2020, https://doi.org/10.1038/s41564-020-0714-0). The establishment of a USUV infection model in immunocompetent adult mice brings new perspectives on the inflammatory component of viral encephalitis, which is difficult to study in mice lacking antiviral interferon responses. Moreover, USUV is an emerging viral disease lacking therapeutic and preventive measures. The interplay of USUV pathogenesis and the host's immune response indicates that lymphocytes and monocytes participate in USUV infection in this model and could be explored in search of treatments targeting immunopathogenic processes triggered by infection.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0172424"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915786/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-06DOI: 10.1128/jvi.01634-24
Andrew Hudson, Peng Wu, Kyle W Kroll, Brady Hueber, Griffin Woolley, Pixu Shi, R Keith Reeves
{"title":"Longitudinal analysis of rhesus macaque metabolome during acute SIV infection reveals disruption in broad metabolite classes.","authors":"Andrew Hudson, Peng Wu, Kyle W Kroll, Brady Hueber, Griffin Woolley, Pixu Shi, R Keith Reeves","doi":"10.1128/jvi.01634-24","DOIUrl":"10.1128/jvi.01634-24","url":null,"abstract":"<p><p>Persons living with HIV experience significant metabolic dysregulation, frequently resulting in immune and other cellular dysfunction. However, our understanding of metabolism and its relationship to immunity in the context of HIV remains incompletely understood, especially as it relates to the acute and early chronic phases of HIV infection. Herein, we employed mass spectrometry and a simian immunodeficiency virus (SIV)-infected rhesus macaque model to characterize changes in over 500 plasma metabolites throughout SIV infection. This broad metabolomic approach recapitulated known pathogenic signatures of HIV, such as a perturbed tryptophan/kynurenine ratio, but also identified novel metabolic changes. We observed a general decrease in plasma amino acid concentrations, with the notable exceptions of elevated aspartate and glutamate. Acute infection was marked by a transient increase in lactate dehydrogenase activity, indicating a shift toward anaerobic metabolism. Indoleamine 2,3-dioxygenase activity, defined by the kynurenine/tryptophan ratio, was significantly increased in both acute and chronic phases and strongly correlated with viral load. These results provide a comprehensive characterization of metabolic fluctuations during early lentiviral infection, furthering our understanding of the crucial interplay between metabolism and immune response. Our findings highlight systemic metabolic consequences of infection and provide potential targets for therapeutic intervention or biomarkers of disease progression.</p><p><strong>Importance: </strong>Despite significant advances in antiretroviral therapy and pre-exposure prophylaxis, HIV remains a global challenge. Understanding the underlying immune mechanisms is critical for improving HIV control and therapeutic development. Cellular metabolism represents a crucial yet underappreciated area of immune system function. Metabolite availability and metabolic pathway preferences directly influence the functional response capacity of immune cells and are highly dysregulated during HIV infection. To further the understanding of metabolic impacts of HIV infection, we utilized cutting-edge mass spectrometry-based metabolome interrogation to measure over 500 metabolites using an acute simian immunodeficiency virus infection model in rhesus macaques. Our comprehensive analysis provides insights into the dynamic metabolic landscape throughout early infection, revealing both known and novel metabolic signatures. These findings enhance our understanding of the complex interplay between metabolism and immunity in lentiviral infections, potentially informing new strategies for early detection, prevention, and treatment of HIV.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0163424"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915796/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143256012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Journal of VirologyPub Date : 2025-03-18Epub Date: 2025-02-11DOI: 10.1128/jvi.02172-24
Saptarshi Ghosh, Banani Mondal, Ola Jassar, Murad Ghanim, Saurabh Gautam, Vamsidhar Reddy Netla, Rajagopalbabu Srinivasan
{"title":"Begomovirus capsid proteins interact with cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase of its whitefly vector and modulate virus retention within its vector.","authors":"Saptarshi Ghosh, Banani Mondal, Ola Jassar, Murad Ghanim, Saurabh Gautam, Vamsidhar Reddy Netla, Rajagopalbabu Srinivasan","doi":"10.1128/jvi.02172-24","DOIUrl":"10.1128/jvi.02172-24","url":null,"abstract":"<p><p>Begomoviruses are whitefly-transmitted ss-DNA viruses that infect dicotyledonous plants and contribute to major economic losses to global crop production. Invasion and establishment of an aggressive cryptic species of <i>Bemisia tabaci</i>, known as the B cryptic species, has severely constrained vegetable production in the southeastern and southwestern United States. Disruption of genes/pathways critical for whitefly-mediated transmission can be effective for the management of begomoviruses. In this study, yeast two-hybrid (Y2H)-based screening of <i>B. tabaci</i> cDNA library identified a cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase-4 (PDE4) of the whitefly as an interacting partner with capsid proteins (CPs) of old- and new-world begomoviruses. Interactions of PDE4 with begomovirus CPs were validated by glutathione-S-transferase (GST) pull-down assay and co-immunolocalization in whitefly midgut. The PDE4 family of enzymes hydrolyzes cAMP and regulates intracellular cAMP levels. This study conclusively proves that acquisition of begomoviruses downregulates the expression of PDE4 (mRNA and protein) resulting in elevated cAMP levels within the whitefly. The role of cAMP post virus acquisition is further elucidated wherein elevation of cAMP by chemical inhibition or gene (PDE4) silencing resulted in increased retention and transmission of begomoviruses. Similarly, decreased cAMP levels resulted in reduced begomovirus retention. The results of this study demonstrate that whitefly-mediated transmission of begomoviruses is regulated by intracellular cAMP by unknown mechanisms.</p><p><strong>Importance: </strong>Begomoviruses, transmitted by the sweetpotato whitefly (<i>Bemisia tabaci</i> Gennadius), are the causal agents of many economically important plant virus diseases. Lack of host plant resistance against begomoviruses, high whitefly abundance, and whitefly's ability to develop insecticide resistance rapidly often render the commonly used management practice ineffective. This study demonstrates how begomovirus retention within whitefly and its transmission can be modulated by altering cyclic adenosine monophosphate (cAMP) expression of its insect vector. Naturally occurring bio-pesticides that target insect cAMPs are known. Our findings can lead to alternative strategies for the management of begomoviruses by targeting whitefly cAMP using chemicals, botanicals, or RNAi-based insecticides.</p>","PeriodicalId":17583,"journal":{"name":"Journal of Virology","volume":" ","pages":"e0217224"},"PeriodicalIF":4.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11915853/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143391112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}