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Simple Summary: High-risk human papillomavirus (HR-HPV) infection is recognized as the primary cause of nearly all cervical cancer cases. However, the evidence suggests that HPV alone may not be sufficient to drive cervical carcinogenesis, pointing to additional co-factors. Notably, recent findings highlight that human cytomegalovirus (HCMV), a herpesvirus commonly detected in cervical lesions, may amplify cancer-related processes. This review examines the current literature on the possible synergistic role of HR-HPV and HCMV in cervical cancer development. The literature reviewed suggests that HCMV could work alongside HR-HPV to disrupt cellular stability, weaken immune defenses, and promote ongoing malignant transformation, potentially accelerating cervical carcinogenesis. Background: Cervical cancer remains a significant health concern worldwide and the primary cause of cancerous cervical lesions is the infection with high-risk human papillomavirus (HR-HPV). However, emerging evidence suggests that HR-HPV infection alone is insufficient for cancer development, and other co-factors may contribute to cervical carcinogenesis. Human cytomegalovirus (HCMV), a common herpesvirus frequently detected in cervical cancer samples, has demonstrated oncogenic potential. Objectives: This review aims to explore the molecular interactions between HR-HPV and HCMV in promoting cervical cancer progression. Methods. A comprehensive search was conducted in PubMed and Google Scholar, focusing on articles examining the role of HCMV in cervical tissues and/or cells, selected based on relevance and significance. Results: The reviewed literature indicates that HCMV and HR-HPV share several oncogenic mechanisms that could drive cervical cell transformation. Conclusions. Both viruses may synergistically promote cervical epithelial transformation and tumor progression in multiple ways. HR-HPV may facilitate HCMV entry by increasing host cell receptors essential for viral attachment. Additionally, HR-HPV and HCMV may cooperatively disrupt cellular processes, enhancing carcinogenesis. Both viruses may also modulate the local immune environment, enabling immune evasion and lesion persistence. However, further in vitro and in vivo studies are required to validate these hypotheses. [ABSTRACT FROM AUTHOR]

Purpose: To explore the potential risk factors for the occurrence of human cytomegalovirus (HCMV) retinitis (CMVR) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients. Methods: This is a retrospective, nested case-control study conducted in hematological patients with CMVR who underwent allo-HSCT. Patients diagnosed with CMVR after allo-HSCT were included as the case group, and those without CMVR were matched by a ratio of 1:2 and were recruited as controls. We selected 19 pre- and post-transplant indicators for univariate analysis between the cases and controls, and then Logistic regression analysis was used to calculate the odds ratio (OR) and 95% confidence intervals (CI) for exploration of risk factors of the CMVR occurrence. Results: A total of 1308 allo-HSCT patients from January 1, 2020 to July 31, 2023 were analyzed, and 27 patients were diagnosed CMVR with a median onset time of 222 days after transplantation. In univariate analysis, donors of stem cells source, HLA-match types (including matched sibling donor, haploidentical donor, and unrelated donor), post-transplant Epstein-Barr virus (EBV) viremia, platelet implantation time, and serostatus of CMV-IgG were more easily to develop CMVR than controls (p < 0.001, p = 0.003, p < 0.001, p = 0.032, p = 0.038, respectively). Multivariate logistic regression analysis showed that stem cells source (OR 7.823, 95% CI 1.759-34.800), HLA-match types (OR 7.452, 95% CI 1.099-50.542), and post-transplant EBV infection (OR 7.510, 95% CI 1.903-29.640) were positively associated with the onset of CMVR. Conclusion: Stem cells derived from bone marrow and peripheral blood, HLA-match types, and post-transplant EBV viremia are important risk predictors of CMVR in allo-HSCT patients. These results suggest that clinicians should pay more attention to these indicators when formulating preventive measures pre- and post-transplant. [ABSTRACT FROM AUTHOR]

Antibodies are key proteins in the immune system that can reversibly and non-covalently bind specifically to their corresponding antigens, forming antigen–antibody complexes. They play a crucial role in recognizing foreign or self-antigens during the adaptive immune response. Monoclonal antibodies have emerged as a promising class of biological macromolecule therapeutics with broad market prospects. In the process of antibody drug development, a key engineering challenge is to improve the affinity of candidate antibodies, without experimentally resolved structures of the antigen–antibody complexes as input for computer-aided predictive methods. In this work, we present an approach for predicting the effect of residue mutations on antibody affinity without the structures of the antigen–antibody complexes. The method involves the graph representation of proteins and utilizes a pre-trained encoder. The encoder captures the residue-level microenvironment of the target residue on the antibody along with the antigen context pre- and post-mutation. The encoder inherently possesses the potential to identify paratope residues. In addition, we curated a benchmark dataset specifically for mutations of the antibody. Compared to baseline methods based on complex structures and sequences, our approach achieves superior or comparable average accuracy on benchmark datasets. Additionally, we validate its advantage of not requiring antigen–antibody complex structures as input for predicting the effects of mutations in antibodies against SARS-CoV-2, influenza, and human cytomegalovirus. Our method shows its potential for identifying mutations that improve antibody affinity in practical antibody engineering applications. [ABSTRACT FROM AUTHOR]

Background and Objectives: Human cytomegalovirus (HCMV) infection is the most common cause of congenital infection during pregnancy. It is a major concern worldwide with a wide range of clinical outcomes in fetuses and newborns due to HCMV reactivation or reinfection during pregnancy. Primary maternal infection is best diagnosed by examining IgM and IgG antibodies. The current study aimed epidemiology survey of congenital HCMV infection in pregnant women in Diwaniyah. Materials and Methods: 600 blood samples were collected from pregnant women, between 18-45 years old, in Diwaniyah Governorate for 12 months, from January to December 2022, in regards to their place of residence (urban or rural). All samples were monitored for both IgG and IgM antibodies against HCMV using rapid test and ELISA. Results: Our findings showed a high positive rate for IgG (95.7%) and (96.2%) and a positive rate for IgM (1.5%) and (1.8%) for rapid test and ELISA, respectively. The highest IgG positive rate was in the age group 26-35 years (43.33%), while the lowest rate (13.0%) was in the age group 36-45 years. The HCMV infection rate in rural and urban areas were (96.48%) and (95.26%), respectively, with no significant differences (P value>0.05). Also, the rate of miscarriages among pregnant women infected with HCMV was 28.83%, and the highest infection rate (30.51%) was recorded in the age group 26-35 years. Conclusion: The prevalence of HCMV infection and its related miscarriage among the studied population is relatively high with the highest rate in the age group of 26-35 years. [ABSTRACT FROM AUTHOR]

Simple Summary: Human cytomegalovirus (HCMV) has been suggested as a potential contributor to breast cancer (BC) development, though its role remains the subject of ongoing debate. This review examines the epidemiological evidence linking HCMV infection to BC and explores the molecular mechanisms by which the virus may contribute to cancer initiation and progression. The current literature reveals a higher prevalence of HCMV in BC tissues compared to normal or benign breast tissues. Furthermore, in vitro studies suggest that HCMV can activate key pathways involved in tumor growth, survival, and metastasis. The virus may also influence the tumor microenvironment and immune responses, fostering conditions that promote cancer progression. Finally, the evidence indicates that certain HCMV strains possess oncogenic properties and may be associated with more aggressive BC subtypes. However, further research is necessary to confirm these findings and translate them into practical clinical applications. Breast cancer (BC) remains a significant global health challenge, highlighting the need for continued research into novel risk factors, diagnostic approaches, and personalized treatments. Among emerging risk factors, viral infections have been implicated as potential contributors to breast carcinogenesis and BC progression. Recent evidence suggests that specific oncogenic strains of human cytomegalovirus (HCMV) may have the capacity to transform human mammary epithelial cells. This review assesses clinical data regarding HCMV presence in both tumor and non-tumor breast tissues, examining the role of HCMV oncoproteins in BC development and progression. Current findings indicate a higher prevalence of HCMV infection in breast carcinomas compared to non-tumor tissues, associated with an elevated risk of BC. Additionally, the HCMV-driven breast carcinogenesis model proposed here suggests that HCMV oncoproteins may activate multiple oncogenic pathways, fostering cell proliferation, survival, and tumor development. A deeper understanding of the role of HCMV in BC could enhance risk stratification and support the creation of targeted therapeutic strategies. [ABSTRACT FROM AUTHOR]

Quinazolines, particularly fluoro-quinazolines, represent important structural motifs in bioactive molecules and pharmaceuticals. Despite several known synthetic routes, the efficient synthesis of fluorine-containing quinazolines remains a challenge. Herein, the straightforward and sustainable synthesis of fluorine-substituted quinazolines using domino sequences is reported. The obtained novel fluoro-quinazoline compounds exhibit significant in vitro activity against human cytomegalovirus (HCMV), expanding the library of potential antiviral drug compounds. Our finding outlays the synthetic toolkit for fluoro-quinazolines and introduces new agents for HCMV therapy. [ABSTRACT FROM AUTHOR]

Background/Objectives: Human cytomegalovirus (HCMV) DNAemia remains a significant concern for transplant recipients, largely due to mutations in the viral genome that may lead to antiviral-resistant strains. Mutations in the UL97 gene are frequently associated with resistance to ganciclovir (GCV), highlighting the importance of early mutation detection to effectively manage viremia. This study aimed to optimize a Sanger sequencing protocol for analyzing GCV resistance-linked mutations in the HCMV UL97 gene from plasma samples of transplant patients treated at Hospital de Clínicas de Porto Alegre, Rio Grande do Sul, Brazil. Methods: A nested-PCR approach combined with a touchdown PCR method was employed to enhance the sensitivity and specificity of the sequencing analysis. Results: The study sample included various transplants, encompassing solid organ and bone marrow recipients. Among 16 sequenced samples, 8 exhibited nucleotide substitutions resulting in amino acid changes. Notably, the A594V and C603W mutations, associated with GCV resistance, were identified in four samples. Additionally, three mutations with unknown phenotypic impact (P509L, A628T, and H662Y) and two viral polymorphisms (N510S and D605E) were detected. Furthermore, double peaks in the Sanger electropherograms, indicative of mixed viral populations of HCMV were observed in seven samples. Conclusions: The optimized Sanger sequencing protocol provides a cost-effective solution for detecting GCV resistance mutations in HCMV UL97 among transplant recipients. This approach could improve the understanding of HCMV strain dynamics and serve as a valuable tool for long-term patient monitoring, particularly within resource-constrained settings such as the public health systems of middle-income countries. [ABSTRACT FROM AUTHOR]

The human cytomegalovirus (HCMV) encoded chemokine receptor US28 plays a critical role in viral pathogenesis, mediating several processes such as cellular migration, differentiation, transformation, and viral latency and reactivation. Despite significant research examining the signal transduction pathways utilized by US28, the precise mechanism by which US28 activates these pathways remains unclear. We performed a mutational analysis of US28 to identify signaling domains that are critical for functional activities. Our results indicate that specific residues within the third intracellular loop (ICL3) of US28 are major determinants of G-protein coupling and downstream signaling activity. Alanine substitutions at positions S218, K223, and R225 attenuated US28-mediated activation of MAPK and RhoA signal transduction pathways. Furthermore, we show that mutations at positions S218, K223, or R225 result in impaired coupling to multiple Ga isoforms. However, these substitutions did not affect US28 plasma membrane localization or the receptor internalization rate. Utilizing CD34+ HPC models, we demonstrate that attenuation of US28 signaling via mutation of residues within the ICL3 region results in an inability of the virus to efficiently reactivate from latency. These results were recapitulated in vivo, utilizing a humanized mouse model of HCMV infection. Together, our results provide new insights into the mechanism by which US28 manipulates host signaling networks to mediate viral latency and reactivation. The results reported here will guide the development of targeted therapies to prevent HCMV-associated disease. IMPORTANCE Human cytomegalovirus (HCMV) is a ß-herpesvirus that infects between 44% and 100% of the world population. Primary infection is typically asymptomatic and results in the establishment of latent infection within CD34+hematopoietic progenitor cells (HPCs). However, reactivation from latent infection remains a significant cause of morbidity and mortality in immunocompromised individuals. The viral chemokine receptor US28 influences various cellular processes crucial for viral latency and reactivation, yet the precise mechanism by which US28 functions remains unclear. Through mutational analysis, we identified key residues within the third intracellular loop (ICL3) of US28 that govern G-protein coupling, downstream signaling, and viral reactivation in vitro and in vivo. These findings offer novel insights into how US28 manipulates host signaling networks to regulate HCMV latency and reactivation and expand our understanding of HCMV pathogenesis. [ABSTRACT FROM AUTHOR]

Human cytomegalovirus (HCMV) is a betaherpesvirus capable of infecting numerous cell types and persisting throughout an infected individual's life. Disease usually occurs in individuals with compromised or underdeveloped immune systems. Several antivirals exist but have limitations relating to toxicity and resistance. HCMV replication involves upregulation of host proteasomal activities, which play important roles in the temporal stages of replication. Here, we defined the impact on replication kinetics of the proteasome inhibitor, bortezomib. We demonstrate that bortezomib significantly reduces levels of viral genomes and infectious virions produced from a population of cells. Inhibition reduced expression of viral proteins that are influence d by genome synthesis. When added prior to 24 hpi, we observe decreases in PCNA and Cdk1 while increases in p21 whose regulations contribute to efficient replication. This response synergized with an antiviral, maribavir. Since some replication occurred, we tested the hypothesis that a subset of infected cells might break through inhibition. Initially, we simulated bortezomib activities using a mechanistic computational model of late-lytic replication. Upon reducing multiplicity of infection (MOI) in silico, we observed near-identical simulated results compared to experimental data. Next, we analyzed replication using live-cell imaging. This revealed treated cultures do contain a population of cells with fully developed late-stage cytoplasmic assembly compartments but at significantly lower numbers. We refer to this as the effective MOI. Overall, our studies support a hypothesis in which 20S proteasome inhibition disrupts HCMV replication by reducing the MOI to an effective MOI, defined by a fraction of infected cells capable of progressing to fulminant infection. IMPORTANCE Human cytomegalovirus (HCMV) infection and reactivation continues to contribute to morbidity and mortality around the world. Antiviral compounds are available but have limitations. Here, we have defined the impact of the proteasome inhibitor bortezomib on HCMV replication. Proteasomal activities play a critical role in temporal changes required for replication. We demonstrate that disrupting these activities inhibits viral replication while likely supporting increased antiviral activity of the anti-HCMV agent, maribavir. Using a combination of live-cell imaging and computational tools, we discover that a subset of infected cells progresses to fulminant infection, which we define as the effective multiplicity of infection, and this subset would otherwise be missed when analyzing the average of the population. [ABSTRACT FROM AUTHOR]

Background and objectives: The impact of viral infections on disease susceptibility and progression has predominantly been studied in patients with relapse-onset MS (RMS). Here, we determined immune responses to ubiquitous viruses in patients with primary progressive MS (PPMS). Methods: Antibody responses to Epstein–Barr virus (EBV), specifically to the latent EBV nuclear antigen 1 and the lytic viral capsid antigen VCA, human herpesvirus 6 (HHV-6), human cytomegalovirus (HCMV), and measles virus were determined in a cohort of 68 PPMS patients with a mean follow-up of 8 years and compared with 66 healthy controls matched for sex and age. Results: Compared with controls, PPMS patients showed increased humoral immune responses to the EBV-encoded nuclear antigen-1 (EBNA1), but not to the lytic EBV capsid antigen (VCA) or to other viral antigens. Seroprevalence rates for HCMV were significantly higher in PPMS. Antiviral immune responses at baseline did not correlate with disability progression over time. Discussion: Elevated immune responses toward EBNA1 are selectively increased in people with primary progressive disease, indicating a link between EBNA1-targeting immune responses and the development of both RMS and PPMS. Our data also suggest that chronic HCMV infection is associated with progressive MS. [ABSTRACT FROM AUTHOR]

After four decades of intensive research, traditional vaccination strategies for HIV-1 remain ineffective due to HIV-1′s extraordinary genetic diversity and complex immune evasion mechanisms. Cytomegaloviruses (CMV) have emerged as a novel type of vaccine vector with unique advantages due to CMV persistence and immunogenicity. Rhesus macaques vaccinated with molecular clone 68-1 of RhCMV (RhCMV68-1) engineered to express simian immunodeficiency virus (SIV) immunogens elicited an unconventional major histocompatibility complex class Ib allele E (MHC-E)-restricted CD8+ T-cell response, which consistently protected over half of the animals against a highly pathogenic SIV challenge. The RhCMV68-1.SIV-induced responses mediated a post-infection replication arrest of the challenge virus and eventually cleared it from the body. These observations in rhesus macaques opened a possibility that MHC-E-restricted CD8+ T-cells could achieve similar control of HIV-1 in humans. The potentially game-changing advantage of the human CMV (HCMV)-based vaccines is that they would induce protective CD8+ T-cells persisting at the sites of entry that would be insensitive to HIV-1 evasion. In the RhCMV68-1-protected rhesus macaques, MHC-E molecules and their peptide cargo utilise complex regulatory mechanisms and unique transport patterns, and researchers study these to guide human vaccine development. However, CMVs are highly species-adapted viruses and it is yet to be shown whether the success of RhCMV68-1 can be translated into an HCMV ortholog for humans. Despite some safety concerns regarding using HCMV as a vaccine vector in humans, there is a vision of immune programming of HCMV to induce pathogen-tailored CD8+ T-cells effective against HIV-1 and other life-threatening diseases. [ABSTRACT FROM AUTHOR]

Cytomegalovirus (CMV) is a ubiquitous virus that infects most of the human population and causes significant morbidity and mortality, particularly among immunocompromised individuals. Understanding CMV's genetic diversity and evolutionary dynamics is crucial for elucidating its pathogenesis and developing effective therapeutic interventions. This review provides a comprehensive examination of CMV's genetic diversity and evolution, focussing on the role of different genotypes in viral pathogenesis. [ABSTRACT FROM AUTHOR]

All viruses are obligate intracellular parasites that use host machinery to synthesize viral proteins. In infected eukaryotes, viral secreted and transmembrane proteins are synthesized at the endoplasmic reticulum (ER). Many viruses refashion ER membranes into bespoke factories where viral products accumulate while evading host pattern recognition receptors. ER processes are tightly regulated to maintain cellular homeostasis, so viruses must either conform to ER regulatory mechanisms or subvert them to ensure efficient viral replication. Reticulophagy is a catabolic process that directs lysosomal degradation of ER components. There is accumulating evidence that reticulophagy serves as a form of antiviral defense; we call this defense "xERophagy" to acknowledge its relationship to xenophagy, the catabolic degradation of microorganisms by macroautophagy/autophagy. In turn, viruses can subvert reticulophagy to suppress host antiviral responses and support efficient viral replication. Here, we review the evidence for functional interplay between viruses and the host reticulophagy machinery. Abbreviations: AMFR: autocrine motility factor receptor; ARF4: ADP-ribosylation factor 4; ARL6IP1: ADP-ribosylation factor-like 6 interacting protein 1; ATL3: atlastin GTPase 3; ATF4: activating transcription factor 4; ATF6: activating transcription factor 6; BPIFB3: BPI fold containing family B, member 3; CALCOCO1: calcium binding and coiled coil domain 1; CAMK2B: calcium/calmodulin-dependent protein kinase II, beta; CANX: calnexin; CDV: canine distemper virus; CCPG1: cell cycle progression 1; CDK5RAP3/C53: CDK5 regulatory subunit associated protein 3; CIR: cargo-interacting region; CoV: coronavirus; CSNK2/CK2: casein kinase 2; CVB3: coxsackievirus B3; DAPK1: death associated protein kinase 1; DENV: dengue virus; DMV: double-membrane vesicles; EBOV: Ebola virus; EBV: Epstein-Barr Virus; EIF2AK3/PERK: eukaryotic translation initiation factor 2 alpha kinase 3; EMCV: encephalomyocarditis virus; EMV: extracellular microvesicle; ER: endoplasmic reticulum; ERAD: ER-associated degradation; ERN1/IRE1: endoplasmic reticulum to nucleus signalling 1; EV: extracellular vesicle; EV71: enterovirus 71; FIR: RB1CC1/FIP200-interacting region; FMDV: foot-and-mouth disease virus; HCMV: human cytomegalovirus; HCV: hepatitis C virus; HMGB1: high mobility group box 1; HSPA5/BiP: heat shock protein 5; IFN: interferon; IFNG/IFN-γ: interferon gamma; KSHV: Kaposi's sarcoma-associated herpesvirus; LIR: MAP1LC3/LC3-interacting region; LNP: lunapark, ER junction formation factor; MAP1LC3: microtubule-associated protein 1 light chain 3; MAP3K5/ASK1: mitogen-activated protein kinase kinase kinase 5; MAPK/JNK: mitogen-activated protein kinase; MeV: measles virus; MHV: murine hepatitis virus; NS: non-structural; PDIA3: protein disulfide isomerase associated 3; PRR: pattern recognition receptor; PRRSV: porcine reproductive and respiratory syndrome virus; RB1CC1/FIP200: RB1-inducible coiled-coil 1; RETREG1/FAM134B: reticulophagy regulator 1; RHD: reticulon homology domain; RTN3: reticulon 3; RTN3L: reticulon 3 long; sAIMs: shuffled Atg8-interacting motifs; SARS-CoV: severe acute respiratory syndrome coronavirus; SINV: Sindbis virus; STING1: stimulator of interferon response cGAMP interactor 1; SVV: Seneca Valley virus; SV40: simian virus 40; TEX264: testis expressed gene 264 ER-phagy receptor; TFEB: transcription factor EB; TRAF2: TNF receptor-associated factor 2; UIM: ubiquitin-interacting motif; UFM1: ubiquitin-fold modifier 1; UPR: unfolded protein response; VAPA: vesicle-associated membrane protein, associated protein A; VAPB: vesicle-associated membrane protein, associated protein B and C; VZV: varicella zoster virus; WNV: West Nile virus; XBP1: X-box binding protein 1; XBP1s: XBP1 spliced; xERophagy: xenophagy involving reticulophagy; ZIKV: Zika virus [ABSTRACT FROM AUTHOR]

Abstract Human cytomegalovirus (HCMV) infection remains a significant global health challenge, particularly for immunocompromised individuals and newborns. This comprehensive review synthesizes current knowledge on HCMV pathogenesis, prevention, and treatment strategies. We examine the molecular mechanisms of HCMV entry, focusing on the structure and function of key envelope glycoproteins (gB, gH/gL/gO, gH/gL/pUL128-131) and their interactions with cellular receptors such as PDGFRα, NRP2, and THBD. The review explores HCMV’s sophisticated immune evasion strategies, including interference with pattern recognition receptor signaling, modulation of antigen presentation, and regulation of NK and T cell responses. We highlight recent advancements in developing neutralizing antibodies, various vaccine strategies (live-attenuated, subunit, vector-based, DNA, and mRNA), antiviral compounds (both virus-targeted and host-targeted), and emerging cellular therapies such as TCR-T cell approaches. By integrating insights from structural biology, immunology, and clinical research, we identify critical knowledge gaps and propose future research directions. This analysis aims to stimulate cross-disciplinary collaborations and accelerate the development of more effective prevention and treatment strategies for HCMV infections, addressing a significant unmet medical need.

Abstract Background Viral infections are known to induce the occurrence and pathogenesis of systemic lupus erythematosus (SLE). Previous studies have indicated a possible relationship between SLE and human cytomegalovirus (HCMV) infection and have attributed HCMV to be associated with various autoantibodies; however, these studies were constrained by variations in sample size and potential selection bias. Therefore, in the present study, we aimed to elucidate the relationship between HCMV and autoantibodies in patients with SLE by integrating clinical data and genetic susceptibility. Methods Using various statistical methods, we conducted a retrospective analysis of the spectrum of SLE autoantibodies and HCMV infections among patients hospitalized at our center over the past 10 years. Machine learning modeling was used to predict active HCMV infections based on the antinuclear (ANA) spectrum. Moreover, Mendelian randomization (MR) was used to investigate the causal relationship between SLE and HCMV infection. Results In the HCMV group, the levels of ANA, anti-dsDNA, anti-histone antibody (AHA), and anti-nucleosome antibody (ANuA) were significantly increased (P 0.05). Conclusion The ANA spectrum in patients with SLE can be used to predict HCMV infection status. Due to the inherent susceptibility of patients with SLE to HCMV infection, we propose for the first time that if a patient with SLE exhibits high serum titers of ANA, anti-dsDNA, ANuA, and AHA, caution should be exercised for HCMV infection, which can contribute to the clinical assessment of SLE and improve patient prognosis.

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection in developed countries and the most common infectious cause of sensorineural hearing loss and neurodevelopmental impairment. Only a small propor-tion of children with cCMV have a symptomatic disease at birth, while a larger proportion of them are asymptomatic. Nevertheless, all children with cCMV are at risk of developing long-term neurodevelopmental impairment, especially sensorineural hearing loss. According to the incidence, we would currently expect 24 children with cCMV annually in Slovenia, four to five of whom would have a neurodevelopmental impairment due to cCMV. Diagnosis of cCMV is based on evidence of viral DNA in a saliva, urine or blood sample taken within the first three weeks after birth. The gold standard for diagnosis of cCMV is evidence of viral DNA in urine, while confirmation of viral DNA in dried blood spots collected within the first days after birth represents the gold standard for retrospective diagnosis of cCMV in children older than three weeks. After establishing a molecular diagnosis of cCMV, it is necessary to assess the organ impairment with laboratory, neuro-radiological, audiological and ophthalmological tests, on which depends the treatment decision. This review article describes the past and modern diagnostics of cCMV, which allows an individualized management approach and predicts the long-term neurodevelopmental outcome of the disease.

Development of antigen-specific memory upon pathogen exposure is a hallmark of the adaptive immune system. While natural killer (NK) cells are considered part of the innate immune system, humans exposed to the chronic viral pathogen cytomegalovirus (CMV) often possess a distinct NK cell population lacking in individuals who have not been exposed, termed "adaptive" NK cells. To identify the "naïve" population from which this "memory" population derives, we performed phenotypic, transcriptional, and functional profiling of NK cell subsets. We identified immature precursors to the Adaptive NK cells that are equally present in both CMV+ and CMV- individuals, resolved an Adaptive transcriptional state distinct from most mature NK cells and sharing a common gene program with the immature CD56bright population, and demonstrated retention of proliferative capacity and acquisition of superior IFNγ production in the Adaptive population. Furthermore, we distinguish the CD56bright and Adaptive NK populations by expression of the transcription factor CXXC5, positioning these memory NK cells at the inflection point between innate and adaptive lymphocytes. [ABSTRACT FROM AUTHOR]

Human cytomegalovirus (HCMV) is a herpes virus with a long replication cycle. HCMV encoded long non-coding RNA termed RNA2.7 is the dominant transcript with a length of about 2.5kb, accounting for 25% of total viral transcripts. Studies have shown that HCMV RNA2.7 inhibits apoptosis caused by infection. The effect of RNA2.7 on other forms of cell death is still unclear. In this work, we found that RNA2.7 deletion significantly decreased the viability of HCMV-infected cells, while treatment with ferroptosis inhibitor Fer-1 rescued the infection-induced cell death, demonstrating an anti-ferroptosis role of RNA2.7. The results further showed that RNA2.7 inhibited ferroptosis via enhancing Ferritin Heavy Chain 1 (FTH1) and Solute Carrier Family 7 Member 11 (SLC7A11) expression in Erastin treated cells without involving other viral components. Pooled Genome-wide CRISPR screening revealed zinc finger protein 395 (ZNF395) as a new regulator repressing the expression of FTH1 and SLC7A11. HCMV RNA2.7 promoted proteasome-mediated degradation of ZNF395 that resulted in upregulation of FTH1 and SLC7A11 to inhibit ferroptosis, therefore maintain survival in host cells and complete replication of virus. Author summary: Human cytomegalovirus (HCMV) exhibits a latency that persists throughout life following the primary infection. Approximately 0.6% of newborns are HCMV-congenitally infected, 20–25% of which are symptomatic at birth or will develop long-term sequelae with a substantial public health impact. HCMV is slow-replicating virus that maintains the survival of the host cell to ensure virus replication. Several HCMV encoded proteins have been found to inhibit apoptosis and necroptosis following viral infection. However, the role of HCMV in other types of programmed cell death such as ferroptosis has not been clarified. In this study, we found that HCMV RNA2.7 inhibited ferroptosis independent on other viral components. Then we tried to explore how RNA2.7 inhibit ferroptosis and found RNA2.7 effectively increased ferritin and GSH contents to dampen ferroptosis. However, the regulation of RNA2.7 on ferritin and GSH contents was not depend on any previously reported regulators. Therefore, a pooled genome-wide CRISPR was employed and ZNF395 was determined as a newly regulator that promoted ferroptosis. Then, we confirmed that HCMV RNA2.7 promoted proteasome-mediated degradation of ZNF395 that resulted in upregulation of FTH1 and SLC7A11 to inhibit ferroptosis, therefore maintain survival in host cells and complete replication of virus. [ABSTRACT FROM AUTHOR]

In the aim of designing and developing a novel saponin-based adjuvant system, we combined the QS21 saponin with low microgram amounts of the fully synthetic TLR4 agonist, E6020, in cholesterol-containing liposomes. The resulting adjuvant system, termed SPA14, appeared as a long-term stable and homogeneous suspension of mostly unilamellar and a few multilamellar vesicles, with an average hydrodynamic diameter of 93 nm, when formulated in citrate buffer at pH 6.0-6.5. When compared in an in vitro human innate immunity construct to AS01B, the QS21/MPL® liposomal adjuvant system of GSK, and with QS21-Liposomes used as benchmarks, SPA14 displayed the strongest immunostimulatory potential based on antigen-presenting cell (APC) activation and cytokine secretion, which was essentially driven by the highly active E6020 agonist in this assay. When tested as an adjuvant in vivo with human cytomegalovirus glycoprotein B (gB) and pentamer complex (PC) as test antigens, SPA14 was generally well tolerated and as active as AS01B for the induction of long-lasting CMV-neutralizing antibodies in mice and non-human primates (NHPs). Both adjuvants promoted the induction of Th-1 responses based on IgG2c production in mice and IFN-γ production in mice and NHPs, but in mice, a higher level of Th-2 cytokines (IL-5) and higher IgG1 over IgG2c secreting cells ratios were obtained with SPA14 indicating that the adjuvant profile of SPA14 could be less Th-1 biased than that of AS01B. From a developability standpoint, SPA14 could be manufactured by a simple and scalable ethanol injection method, owing to the high solubility in ethanol of all its lipidic components, including E6020. Furthermore, E6020 is a single molecule, well-characterized fully synthetic TLR4 agonist constructed in eight synthetic steps from entirely crystalline starting materials and intermediates via an optimized high-yield synthetic route. Overall, our data suggest that SPA14 is a viable, easy-to-manufacture, potent novel adjuvant system that could be broadly applicable as a ready-to-mix adjuvant in the form of a long-term stable liquid formulation. [ABSTRACT FROM AUTHOR]

This study focuses on the common presence of repetitive sequences within the sturgeon genome that may contribute to enhanced immune responses against infectious diseases. A repetitive 675 bp VAC-2M sequence in Russian sturgeon DNA that aligns with the Siberian sturgeon IGLV gene cluster was identified. A specific 218 bp long portion of the sequence was found to be identical between Acipenser gueldenstaedtii, A. baerii and A. stellatus species, and NCBI blast analysis confirmed the presence of this DNA segment in the A. ruthenus genome. Multiple mutated copies of the same genomic region were detected by PCR analysis, indicating that different versions of this highly repetitive sequence exist simultaneously within the same organism. The selection toward specific genetic differences appears to be highly conserved based on the sequence variations within DNA originating from fish grown at distant geographical regions and individual caviar grains from the same fish. The corresponding A. baerii genomic region encompassing the 357 bp DNA sequence was cloned either ahead or after the human cytomegalovirus immediate early promoter (HCMV-IE) into a pBV-Luc reporter vector expressing the luciferase gene. The DNA segment significantly reduced luciferase expression in transient transfection/expression experiments. The results indicate that this genomic region functions as a transcription termination element that may affect antibody production in sturgeons. [ABSTRACT FROM AUTHOR]

Cytomegaloviruses are highly species-specific as they replicate only in cells of their own or a closely related species. For instance, human cytomegalovirus cannot replicate in rodent cells, and mouse cytomegalovirus (MCMV) cannot replicate in human and monkey cells. However, the mechanisms underlying the host species restriction remain poorly understood. We have previously shown that passaging MCMV in human retinal pigment epithelial cells allows the virus to replicate to high titers in these cells due to the accumulation of adaptive mutations, such as loss-of-function mutations in the viral M117 gene. The M117 protein interacts with E2F transcription factors and activates E2F-dependent transcription. Here, we show that activation of E2F3 is primarily responsible for MCMV's inability to replicate in human cells. By transcriptome analysis, we identified two E2F3-induced serine proteases, FAM111A and FAM111B, as potential host restriction factors. By using shRNA-mediated gene knockdown and CRISPR/Cas9-mediated gene knockout, we demonstrated that FAM111B, but not its paralog FAM111A, suppresses MCMV replication in human and rhesus macaque cells. By immunofluorescence, we detected FAM111B predominantly in the nucleus of infected cells with enrichment in viral replication compartments, suggesting that it might play a role during viral replication. The fact that the FAM111B gene is conserved in primates but absent in rodents suggests that MCMV has not evolved to evade or counteract this restriction factor, which is not present in its natural host. [ABSTRACT FROM AUTHOR]

Cytotoxic CD4+ T cells eliminate human cytomegalovirus (HCMV)-infected cells through direct cytotoxic granules exocytosis. We aimed to evaluate the functional cytotoxic gene profile of CD4+ T cells alongside the frequency of the cytotoxic phenotype in renal transplant recipients with cytomegalovirus reactivation. Blood samples were collected from twenty renal recipients with and without HCMV reactivation (HCMV+ and HCMV- groups) and ten healthy adults (control group). CD4+ T cells were isolated to assess the frequency of cytotoxic CD4+ T cells via CD107a surface staining using flow cytometry and to evaluate gene expression of perforin, granzyme B, Runt-related transcription factor 3 (RUNX3), and Eomesodermin (Eomes) by quantitative PCR. The frequency of CD4+ CD107a+ T cells was higher in the HCMV+ group compared to the HCMV- group and significantly higher than in the control group (22.69 ± 3.47 vs 16.41 ± 2.24 and 11.60 ± 1.17, respectively). Perforin gene levels were reduced in the HCMV+ group compared to the other two groups, while granzyme B gene levels were similar between HCMV+ and HCMVgroups but lower than in the control group (0.63 ± 1.24 vs 0.67 ± 2.27 and 1.00 ± 0.00, respectively). This study demonstrated an increased frequency of cytotoxic CD4+ T cells with potentially reduced functionality in kidney transplant patients with HCMV infection. It also suggests that these cells might employ other mechanisms, such as death receptor-mediated killing, or the production of other granules. [ABSTRACT FROM AUTHOR]

Plasma-soluble (s)HLA-G and sHLA-E are immunoregulatory proteins that balance the activation of NKG2A+ immune cells. In lung-transplant recipients (LTRs), dysregulated NKG2A+ natural killer cell responses may result in high-level human cytomegalovirus (HCMV) replication as well as chronic lung allograft dysfunction (CLAD), and especially the development of rapidly deteriorating CLAD is associated with high mortality. We thus analyzed the kinetics and function of sHLA-G and sHLA-E in follow-up samples of N = 76 LTRs to evaluate whether these immunoregulatory proteins are associated with the risk for CLAD and high-level HCMV replication. Here, we demonstrate that rapidly deteriorating CLAD LTRs are hallmarked by continually low (<107 ng/ml) sHLA-G levels. In contrast, high sHLA-E levels were associated with the following development of high-level (>1,000 copies/ml) HCMV episodes. Thus, sHLA-G and sHLA-E may serve as novel biomarkers for the development of rapidly deteriorating CLAD and high-level HCMV replication in LTRs. [ABSTRACT FROM AUTHOR]

Monocytes and macrophages are at the frontline of defense against pathogens. Human cytomegalovirus (HCMV) uses myeloid cells as vehicles to facilitate viral dissemination. HCMV infection in monocytes and macrophages leads to the downregulation of several cell surface markers via an undefined mechanism. Previously, we showed that HCMV pUL42 associates with the Nedd4 family ubiquitin E3 ligases through the PPXY motif on pUL42 and downregulates Nedd4 and Itch proteins in HCMV‐infected fibroblasts. Homologous proteins of HCMV pUL42, such as HHV‐6 U24, downregulate cell surface markers. To reveal the downregulation property of pUL42, we focused on CD86, the key costimulatory factor for acquired immunity. Here, we constructed CD86‐expressing THP‐1 cells using a retroviral vector and analyzed the effects of HCMV infection and pUL42 on CD86 downregulation. Disruption of the PPXY motifs of pUL42 (UL42PA) decelerated the degradation of CD86 in recombinant virus‐infected cells, indicating the involvement of Nedd4 family functions. However, no direct interactions were observed between CD86 and Itch. Interestingly, unlike fibroblast infection, the expression of Nedd4 and Itch proteins increased in HCMV‐infected THP‐1 cells, accompanied by an increase in their transcript levels. Although the function of pUL42 did not relate to the increase of Nedd4 and Itch proteins, pUL42 should affect these Nedd4 proteins to downregulate CD86. [ABSTRACT FROM AUTHOR]

Placental trophoblasts constitute the interface between the fetal and maternal environments and physically prevent maternal–fetal viral transmission. However, congenital human cytomegalovirus (HCMV) infection in the early stages of pregnancy results in severe symptoms in the fetus. HCMV is the most common causative agent of intrauterine infection. To clarify the etiology of congenital HCMV infection, we focused on how the placental environment affects HCMV infection. We investigated the role of microRNAs (miRNAs), which are highly and specifically expressed in placental trophoblasts. The transfection of trophoblast‐specific C19MC miRNAs, encoded by the chromosome 19 miRNA cluster, markedly enhanced HCMV Immediate Early (IE) gene expression and subsequent viral production. However, the expression of the herpes simplex virus type‐1 IE gene was not changed by C19MC‐BAC transfection. From among 46427 mapped genes, we identified that the expression of RAC2, a Rac family small GTPase, was markedly suppressed with an independent genetic hierarchical cluster by C19MC‐BAC transfection. The suppression of RAC2 expression enhanced HCMV IE gene expression. Here, we propose the hypothesis that the placental environment contributes to HCMV‐specific replication via the trophoblast‐specific miRNA‐mediated downregulation of RAC2 expression. [ABSTRACT FROM AUTHOR]

Human cytomegalovirus (HCMV) rarely infects the brain following infection of adult individuals. However, the virus readily infects the brain during congenital HCMV (cHCMV) infection, frequently causing severe neurodevelopmental and neurological sequelae. Interestingly, although the incidence of cHCMV infection is 0.5–1%, the proportion of congenitally infected individuals in which the virus manages to gain access to the brain is unknown. In this study, we used infection of mice with mouse cytomegalovirus (MCMV), the most commonly used experimental system for modeling HCMV disease in humans, to determine the impact of age on the susceptibility of the brain to cytomegalovirus infection and infection-mediated neuroinflammation. We demonstrate that infection of mice during various stages of neonatal development can lead to CMV neuroinvasion and inflammation. In contrast, MCMV infection does not result in MCMV neuroinvasion and neuroinflammation in weanling and adult mice. The obtained results establish a basis for elucidating the mechanisms of CMV neuroinvasion and the deleterious inflammatory response during ontogeny. [ABSTRACT FROM AUTHOR]

Background: Viral infections are known to induce the occurrence and pathogenesis of systemic lupus erythematosus (SLE). Previous studies have indicated a possible relationship between SLE and human cytomegalovirus (HCMV) infection and have attributed HCMV to be associated with various autoantibodies; however, these studies were constrained by variations in sample size and potential selection bias. Therefore, in the present study, we aimed to elucidate the relationship between HCMV and autoantibodies in patients with SLE by integrating clinical data and genetic susceptibility. Methods: Using various statistical methods, we conducted a retrospective analysis of the spectrum of SLE autoantibodies and HCMV infections among patients hospitalized at our center over the past 10 years. Machine learning modeling was used to predict active HCMV infections based on the antinuclear (ANA) spectrum. Moreover, Mendelian randomization (MR) was used to investigate the causal relationship between SLE and HCMV infection. Results: In the HCMV group, the levels of ANA, anti-dsDNA, anti-histone antibody (AHA), and anti-nucleosome antibody (ANuA) were significantly increased (P < 0.001) and were linked to the presence of CMV-pp65-antigen-positive polymorphonuclear leukocytes (P < 0.001). A weak correlation was observed between the titers of anti-CMV IgM and ANA (P < 0.001). The ANA spectrum demonstrated a strong predictive performance for active HCMV infection based on principal component analysis (Adonis and ANOSIM P < 0.001) as well as support vector machine and extreme gradient boosting modeling. MR analyses of inverse-variance weighted, weighted mean, MR-Egger, and weighted mode revealed that patients with SLE were at a higher risk of developing HCMV infection (P < 0.05). However, HCMV infection did not have a causal effect on SLE (P > 0.05). Conclusion: The ANA spectrum in patients with SLE can be used to predict HCMV infection status. Due to the inherent susceptibility of patients with SLE to HCMV infection, we propose for the first time that if a patient with SLE exhibits high serum titers of ANA, anti-dsDNA, ANuA, and AHA, caution should be exercised for HCMV infection, which can contribute to the clinical assessment of SLE and improve patient prognosis. [ABSTRACT FROM AUTHOR]

Viruses with broad tissue distribution and cell tropism successfully replicate in various nutrient environments in the body. Several viruses reprogram metabolism for viral replication. However, many studies focus on metabolic reprogramming in nutrient-rich conditions that do not recapitulate physiological environments in the body. Here, we investigated how viruses may replicate when a metabolite thought to be essential for replication is limited. We use human cytomegalovirus infection in glucose-free conditions as a model to determine how glucose supports virus replication and how physiologically relevant nutrients contribute to glucose-independent virus production. We find that glucose supports viral genome synthesis, viral protein production and glycosylation, and infectious virus production. Notably, supplement of glucose-free cultures with uridine, ribose, or UDP-GlcNAc—metabolites that feed upper glycolytic branches like the pentose phosphate pathway—results in partially restored virus replication, including low levels of infectious virus production. Supplementing lower glycolysis in glucose-free cultures using pyruvate fails to restore virus replication. These results indicate that nutrients can compensate for glucose via feeding upper glycolytic branches to sustain low levels of virus production. More broadly, our findings suggest that viruses may successfully replicate in diverse metabolic niches, including those in the body with low glucose levels, through alternative nutrient usage. [ABSTRACT FROM AUTHOR]

Human cytomegalovirus (HCMV) infection remains a significant global health challenge, particularly for immunocompromised individuals and newborns. This comprehensive review synthesizes current knowledge on HCMV pathogenesis, prevention, and treatment strategies. We examine the molecular mechanisms of HCMV entry, focusing on the structure and function of key envelope glycoproteins (gB, gH/gL/gO, gH/gL/pUL128-131) and their interactions with cellular receptors such as PDGFRα, NRP2, and THBD. The review explores HCMV's sophisticated immune evasion strategies, including interference with pattern recognition receptor signaling, modulation of antigen presentation, and regulation of NK and T cell responses. We highlight recent advancements in developing neutralizing antibodies, various vaccine strategies (live-attenuated, subunit, vector-based, DNA, and mRNA), antiviral compounds (both virus-targeted and host-targeted), and emerging cellular therapies such as TCR-T cell approaches. By integrating insights from structural biology, immunology, and clinical research, we identify critical knowledge gaps and propose future research directions. This analysis aims to stimulate cross-disciplinary collaborations and accelerate the development of more effective prevention and treatment strategies for HCMV infections, addressing a significant unmet medical need. [ABSTRACT FROM AUTHOR]

Background: Human memory NK cells represent a heterogeneous CD56dim population that expands and persists in human cytomegalovirus (HCMV)-seropositive healthy individuals. They are characterized by the preferential, not fully overlapping, expression of NKG2C (activating receptor for HLA-E) and CD57 maturation marker, and by the lack of FcεRIγ adaptor chain. Hyperresponsiveness to Fcγ receptor IIIA (CD16) engagement represents the distinctive functional signature of memory NK cells. Although CD16 engagement was shown to acutely enhance glycolytic and oxidative pathways, its capability to induce a persisting metabolic reprogramming of human NK cells is poorly understood yet. Results: Here, we describe the peculiar nutrient transporter expression pattern of FcεRIγ- memory NK cells, characterized by higher levels of CD98 neutral amino acid antiporter and CD71 transferrin receptor, and lower expression of GLUT1 glucose transporter, with respect to FcεRIγ+ conventional NK cells. Although CD16 engagement acutely enhances glycolytic and oxidative pathways, its capability to induce a persisting metabolic reprogramming of human NK cells is poorly understood yet. Our results firstly show that sustained CD16 engagement by contact with IgG-opsonized target cells induces the mTORC1-dependent upregulation of CD98 and CD71 nutrient receptors on CD56dim NK cells, in a transporter-specific fashion, that is finely tuned by cell-dependent (grade of functional maturation, and memory or conventional lineage) and stimulus-dependent (time length and cooperation with cytokines) factors. We also demonstrate that CD98 antiporter function is required for CD16-dependent IFN-γ production, and that enhanced CD98-mediated neutral amino acid uptake associates with heightened memory NK cell functional response. Conclusion: Collectively, our work documents that CD16 engagement leads to a metabolic rewiring of human NK cells and suggests that a distinct nutrient transporter expression pattern may contribute to memory NK cell peculiar functional features. [ABSTRACT FROM AUTHOR]

Human CMV, regularly reactivated by simple triggers, results in asymptomatic viral shedding, powerful cellular immune responses, and memory inflation. Immunocompetent individuals benefit from a robust immune response, which aids in viral management without causing clinically significant illness; however, immunodeficient individuals are always at a higher risk of CMV reactivation and disease. Hematopoietic stem cell transplant (HSCT) recipients are consistently at higher risk of CMV reactivation and clinically significant CMV illness due to primary disease, immunosuppression, and graft vs. host disease. Early recovery of CMV-CMI responses may mitigate effects of viral reactivation in HSCT recipients. Immune reconstitution following transplantation occurs spontaneously and is mediated initially by donor-derived T cells, followed by clonal growth of T cells produced from graft progenitors. CMV-specific immune reconstitution post-transplant is related to spontaneous clearance of CMV reactivation and may eliminate the need for prophylactic or pre-emptive medication, making it a potential predictive marker for monitoring CMV reactivation. This review highlights current thoughts and therapeutic options for CMV reactivation in HSCT, with focus on CMV immune reconstitution and post-HSCT monitoring. Immune monitoring aids in risk stratification of transplant recipients who may progress from CMV reactivation to clinically significant CMV infection. Implementing this approach in clinical practice reduces the need for periodic viral surveillance and antiviral therapy in recipients who have a high CMV-CMI and thus may experience self-limited reactivation. Therefore, in the age of precision medicine, it is critical to incorporate CMV-specific cellular immune surveillance into conventional procedures and algorithms for the management of transplant recipients. [ABSTRACT FROM AUTHOR]

Background: Gut microbiome dysbiosis and related immune dysfunction have been associated with the pathogenesis of Human Cytomegalovirus (HCMV) infection in infants with neonatal cholestasis (NC) as previously reported by us. However, the interaction of a perturbed microbiome, HCMV infection, and dysregulated immunity leading to exacerbation of disease severity has not been investigated so far. In this study, we examined the association of gut microbiome, host inflammatory and homeostatic markers that are likely to govern increased pathogenesis of NC in HCMV infected IgM positive infants (N = 15) compared to IgM negative (N = 15) individuals. Stool samples of HCMV infected infants and age-matched healthy controls (N = 10) were assessed for gut bacteria-derived metabolites like short-chain fatty acids (SCFAs), Lipopolysaccharide (LPS), cytokines and markers of gut barrier integrity. Data were correlated with previously determined gut microbiome composition and frequency of immune cell subsets. Finally, validation of clinical potential was undertaken by principal component analysis (PCA) of integrated data to delineate the spectrum of clinical pathology. Results: Significantly lower levels of SCFAs and elevated fecal levels of soluble inflammatory mediators were observed in IgM positive HCMV infected infants. Further, increased plasma LPS levels and markers of gut permeability, suggestive of microbial translocation due to a 'leaky gut' were observed in HCMV infected IgM positive group. PCA of integrated data revealed clearly disparate profiles representative of IgM positive, IgM negative, and uninfected healthy states. Conclusion: Our results suggest the utility of an integrated approach involving dysregulated microbiome-immune axis for gaining a better understanding of pathogenesis associated with HCMV infection in NC. [ABSTRACT FROM AUTHOR]

Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are classified into the gammaherpesvirus subfamily of Herpesviridae, which stands out from its alpha- and betaherpesvirus relatives due to the tumorigenicity of its members. Although structures of human alpha- and betaherpesviruses by cryogenic electron tomography (cryoET) have been reported, reconstructions of intact human gammaherpesvirus virions remain elusive. Here, we structurally characterize extracellular virions of EBV and KSHV by deep learning-enhanced cryoET, resolving both previously known monomorphic capsid structures and previously unknown pleomorphic features beyond the capsid. Through subtomogram averaging and subsequent tomogram-guided sub-particle reconstruction, we determined the orientation of KSHV nucleocapsids from mature virions with respect to the portal to provide spatial context for the tegument within the virion. Both EBV and KSHV have an eccentric capsid position and polarized distribution of tegument. Tegument species span from the capsid to the envelope and may serve as scaffolds for tegumentation and envelopment. The envelopes of EBV and KSHV are less densely populated with glycoproteins than those of herpes simplex virus 1 (HSV-1) and human cytomegalovirus (HCMV), representative members of alpha- and betaherpesviruses, respectively. Also, we observed fusion protein gB trimers exist within triplet arrangements in addition to standalone complexes, which is relevant to understanding dynamic processes such as fusion pore formation. Taken together, this study reveals nuanced yet important differences in the tegument and envelope architectures among human herpesviruses and provides insights into their varied cell tropism and infection. IMPORTANCE Discovered in 1964, Epstein-Barr virus (EBV) is the first identified human oncogenic virus and the founding member of the gammaherpesvirus subfamily. In 1994, another cancer-causing virus was discovered in lesions of AIDS patients and later named Kaposi's sarcoma-associated herpesvirus (KSHV), the second human gammaherpesvirus. Despite the historical importance of EBV and KSHV, technical difficulties with isolating large quantities of these viruses and the pleiomorphic nature of their envelope and tegument layers have limited structural characterization of their virions. In this study, we employed the latest technologies in cryogenic electron microscopy (cryoEM) and tomography (cryoET) supplemented with an artificial intelligence-powered data processing software package to reconstruct 3D structures of the EBV and KSHV virions. We uncovered unique properties of the envelope glycoproteins and tegument layers of both EBV and KSHV. Comparison of these features with their non-tumorigenic counterparts provides insights into their relevance during infection. [ABSTRACT FROM AUTHOR]

Human cytomegalovirus (HCMV) is a ubiquitous pathogen that infects the majority of the world's population. Lytic HCMV replication in immunocompromised individuals or neonates can lead to severe disease in multiple organ systems and even death. The establishment of lytic replication is driven by the first viral proteins expressed upon infection, the immediate early proteins, which play a key role in creating an intracellular environment conducive to virus replication. Two immediate early proteins, the functional orthologs pTRS1 and pIRS1, stimulate immediate early gene expression by suppressing antiviral PKR/eIF2α signaling and enhance the translation of viral mRNAs independent of PKR antagonism. To better understand the molecular functions of pTRS1, we used proximity labeling proteomics to identify proteins that interact with pTRS1 in infected cells. Multiple novel host and viral interactors were identified, including the catalytic subunits of the protein phosphatase 1 (PP1) holoenzyme. Mutations to a PP1 catalytic subunit known to disrupt binding to PP1 regulatory subunits decreased binding to pTRS1. pTRS1 immune complexes contained phosphatase activity, and inhibition of phosphatase activity in transfected or infected cells reversed the ability of pTRS1 to inhibit the antiviral kinase PKR. Depletion of individual PP1 catalytic subunits decreased virus replication and increased the phosphorylation of the PKR substrate eIF2α. Taken together, our data suggest potential novel functions for pTRS1 and define a novel role for PP1 as an antagonist of the antiviral PKR/eIF2α signaling axis during HCMV infection. IMPORTANCE The human cytomegalovirus (HCMV) pTRS1 and pIRS1 proteins are critical regulators of HCMV replication, both during primary infection and during reactivation from viral latency. Thus, defining the molecular functions of pTRS1/pIRS1 is important for understanding the molecular events controlling HCMV replication and viral disease. These data provide new insights into potential pTRS1 functional roles, providing a starting point for others to understand new features of infected cell biology. Another important result of this study is the finding that specific protein phosphatase 1 (PP1) regulatory subunits are required to suppress PKR/eIF2α signaling, a critical cellular innate immune defense to viral infection. These data lay the groundwork for future efforts to discover therapeutics that disrupt pTRS1 interaction with PP1 allowing cellular defenses to limit HCMV replication and disease. [ABSTRACT FROM AUTHOR]

Viruses are ubiquitous entities that infect organisms across the kingdoms of life. While viruses can infect a range of cells, tissues, and organisms, this aspect is often not explored in cell culture analyses. There is limited information about which infectioninduced changes are shared or distinct in different cellular environments. The prevalent pathogen human cytomegalovirus (HCMV) remodels the structure and function of subcellular organelles and their interconnected networks formed by membrane contact sites (MCSs). A large portion of this knowledge has been derived from fibro blasts infected with a lab-adapted HCMV strain. Here, we assess strain- and cell type-specific alterations in MCSs and organelle remodeling induced by HCMV. Integrating quantitative mass spectrometry, super-resolution microscopy, and molecular virology assays, we compare infections with lab-adapted and low-passage HCMV strains in fibro blast and epithelial cells. We determine that, despite baseline proteome disparities between uninfected fibroblast and epithelial cells, infection induces convergent changes and is remarkably similar. We show that hallmarks of HCMV infection in fibroblasts, mitochondria-endoplasmic reticulum (ER) encapsulations and peroxisome proliferation, are also conserved in infected epithelial and macrophage-like cells. Exploring cell type-specific differences, we demonstrate that fibroblasts rely on endosomal cholesterol transport while epithelial cells rely on cholesterol from the Golgi. Despite these mechanistic differences, infections in both cell types result in phenotypically similar cholesterol accumulation at the viral assembly complex. Our findings highlight the adaptability of HCMV, in that infections can be tailored to the initial cell state by inducing both shared and unique proteome alterations, ultimately promoting a unified pro-viral environment. IMPORTANCE Human cytomegalovirus (HCMV) establishes infections in diverse cell types throughout the body and is connected to a litany of diseases associated with each of these tissues. However, it is still not fully understood how HCMV replication varies in distinct cell types. Here, we compare HCMV replication with lab-adapted and low-passage strains in two primary sites of infection, lung fibroblasts and retinal epithelial cells. We discover that, despite displaying disparate protein compositions prior to infection, these cell types undergo convergent alterations upon HCMV infection, reaching a more similar cellular state late in infection. We find that remodeling of the subcellular landscape is a pervasive feature of HCMV infection, through alterations to both organelle structure-function and the interconnected networks they form via membrane contact sites. Our findings show how HCMV infection in different cell types induces both shared and divergent changes to cellular processes, ultimately leading to a more unified state. [ABSTRACT FROM AUTHOR]

A subpopulation of NK cells with distinctive phenotype and function differentiates and expands specifically in response to infection by human cytomegalovirus (HCMV). A hallmark of these adaptive NK cells is their increased expression levels of the activating CD94/NKG2C receptor for HLA‐E, and lack of expression of its inhibitory homologue CD94/NKG2A. Their frequency is highly variable in HCMV+ individuals, and the basis for such differences is only partially understood. Here, we explore the possible influence of sequence polymorphism of the NKG2C (or KLRC2) gene on the expansion of NKG2C+NKG2A− NK cells in healthy HCMV‐seropositive donors. Our results show a significant association of greater proportions of adaptive NK cells with allele NKG2C*02. This is defined by two amino acid substitutions in comparison with the most prevalent allele, NKG2C*01, and associates with additional sequence polymorphisms in noncoding regions. Furthermore, we demonstrate consistently higher mRNA levels of NKG2C*02 in heterozygous individuals co‐expressing this allele in combination with NKG2C*01 or *03. This predominance is independent of polymorphisms in the promoter and 3′ UTRs and is appreciated also in HCMV‐seronegative donors. In summary, although additional factors are most likely implicated in the variable expansion of NKG2C+NKG2A− NK cells in response to HCMV, our results demonstrate that host immunogenetics, in particular NKG2C diversity, influences the magnitude of such response. [ABSTRACT FROM AUTHOR]

Cervical cancer remains a significant global health concern, particularly in low- and middle-income countries. While persistent infection with high-risk human papillomavirus (HR-HPV) is essential for cervical cancer development, it is not sufficient on its own, suggesting the involvement of additional cofactors. The human cytomegalovirus (HCMV) is a widespread β-herpesvirus known for its ability to establish lifelong latency and reactivate under certain conditions, often contributing to chronic inflammation and immune modulation. Emerging evidence suggests that HCMV may play a role in various cancers, including cervical cancer, through its potential to influence oncogenic pathways and disrupt host immune responses. This review explores clinical evidence regarding the co-presence of HR-HPV and HCMV in premalignant lesions and cervical cancer. The literature reviewed indicates that HCMV is frequently detected in cervical lesions, particularly in those co-infected with HPV, suggesting a potential synergistic interaction that could enhance HPV's oncogenic effects, thereby facilitating the progression from low-grade squamous intraepithelial lesions (LSIL) to high-grade squamous intraepithelial lesions (HSIL) and invasive cancer. Although the precise molecular mechanisms were not thoroughly investigated in this review, the clinical evidence suggests the importance of considering HCMV alongside HPV in the management of cervical lesions. A better understanding of the interaction between HR-HPV and HCMV may lead to improved diagnostic, therapeutic, and preventive strategies for cervical cancer. [ABSTRACT FROM AUTHOR]

Background: Information related to herpes simplex virus 1 and 2 (HSV-1 and 2), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) seroprevalence in France is either lacking, incomplete, or outdated, despite their public health burden. Method: We used routinely collected serological data between 2018 and 2022 to estimate HSV-1, HSV-2, VZV, EBV, and CMV seroprevalence in France. To account for demographic differences between our analytic samples and the French population and get estimates for sparsely sampled districts and age classes, we used a multilevel regression and poststratification approach combined with Bayesian model averaging via stacking weights. Results: The observed seroprevalence (number of positive tests/number of tests) were 64.6% (93,294/144,424), 16.9% (24,316/144,159), 93.0% (141,419/152,084), 83.4% (63,199/75, 781), and 49.0% (23,276/47,525), respectively, for HSV-1, HSV-2, VZV, EBV, and CMV. Between 2018 and 2022, France had a model-based average (equal-tailed interval at 95%) expected seroprevalence equal to 61.1% (60.7,61.5), 14.5% (14.2,14.81), 89.5% (89.3,89.8), 85.6% (85.2,86.0), and 50.5% (49.3,51.7), respectively, for HSV-1, HSV-2, VZV, EBV, and CMV infections. We found an almost certain lower expected seroprevalence in Metropolitan France than in overseas territories for all viruses but VZV, for which it was almost certainly greater. The expected seroprevalences were likely greater among females for all viruses. Limitations: Our results relied on the assumption that individuals were sampled at random conditionally to variables used to build the poststratification table. Implications: The analysis highlights spatial and demographic patterns in seroprevalence that should be considered for designing tailored public health policies. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is a rapidly growing, life-threatening subtype of blood cancer that mostly affects adults and requires hematopoietic stem cell transplantation (HSCT) as a treatment modality. Strategies such as natural killer (NK) cell-based therapy have been developed to maximize the AML and HSCT immunotherapeutic approach, harnessing the anti-leukemic immune response and graft versus leukemia (GvL) effect. A previous study has demonstrated that human cytomegalovirus (HCMV) reactivation in allogeneic HSCT patients caused a reduction in AML relapse or recurrence of disease, attributed to the killing activity of the adaptive NK cells that express CD56dimNKG-2C+CD57+. Nonetheless, the positive influence of these adaptive NK cells in individuals with high HCMV burden, particularly in AML and HSCT patients, remains uncertain due to insufficient grasp of the receptors and ligands responsible for their anti-tumor actions. In this review, we explore potential utilization of the adaptive or 'memory-like' NK cells in acute leukemia which could potentially be harnessed for anti-leukemia purposes. The understanding will be valuable for the formulation of adoptive immunotherapy strategies, including the development of chimeric antigen receptor (CAR) NK cells possessing the adaptive or 'memory-like' characteristic. [ABSTRACT FROM AUTHOR]

Introduction: Poor graft function (PGF), characterized by myelosuppression, represents a significant challenge following allogeneic hematopoietic stem cell transplantation (allo-HSCT) with human cytomegalovirus (HCMV) being established as a risk factor for PGF. However, the underlying mechanism remains unclear. Bone marrow endothelial progenitor cells (BM-EPCs) play an important role in supporting hematopoiesis and their dysfunction contributes to PGF development. We aim to explore the effects of CMV on BM-EPCs and its underlying mechanism. Methods: We investigated the compromised functionality of EPCs derived from individuals diagnosed with HCMV viremia accompanied by PGF, as well as after infected by HCMV AD 169 strain in vitro, characterized by decreased cell proliferation, tube formation, migration and hematopoietic support, and increased apoptosis and secretion of TGF-β1. Results: We demonstrated that HCMV-induced TGF-β1 secretion by BM-EPCs played a dominant role in hematopoiesis suppression in vitro experiment. Moreover, HCMV down-regulates Vitamin D receptor (VDR) and subsequently activates p38 MAPK pathway to promote TGF-β1 secretion by BM-EPCs. Discussion: HCMV could infect BM-EPCs and lead to their dysfunction. The secretion of TGF-β1 by BM-EPCs is enhanced by CMV through the activation of p38 MAPK via a VDR-dependent mechanism, ultimately leading to compromised support for hematopoietic progenitors by BM EPCs, which May significantly contribute to the pathogenesis of PGF following allo-HSCT and provide innovative therapeutic strategies targeting PGF. [ABSTRACT FROM AUTHOR]

Background: Human cytomegalovirus (HCMV) is a widespread human pathogen that triggers varying clinical symptoms depending on the host's age and immune status. It appears that HCMV infection plays a role in the development of numerous types of cancer. This study aimed to identify the presence of HCMV in different kinds of malignant salivary gland tumors in Sudanese patients. Methods: Eighty-four formalin-fixed paraffin-embedded tissues (FFPE) from Sudanese patients previously diagnosed with salivary gland cancer (SGC) between 2014 and 2022 were selected. All cases include normal salivary gland tissue. Immunohistochemical staining for CMV was performed using monoclonal antibodies to detect the presence of the virus among the studied group. Results: CMV was detected in only 1 out of 84 SGC cases; an adenoid cystic carcinoma. All adjacent normal salivary gland tissues were negative for the virus. Conclusion: The absence of CMV in the studied cases suggests that the virus was not involved in developing these malignancies. [ABSTRACT FROM AUTHOR]

Background: In kidney transplant recipients prone to infections like cytomegalovirus (CMV), a vital need for an accurate diagnostic method is evident. This study at Khorshid Laboratory in Tehran rigorously compares real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) for CMV detection in transplant patients. Methods: In January to March 1400, 70 kidney transplant recipients were assessed for CMV DNA using RT-PCR and concurrent ELISA tests, with statistical analysis aided by SPSS. Results: In kidney transplant patients (average age: 49.40 ± 13.64 years), 4.3% tested positive for CMV via PCR. Strong correlation between serological and molecular methods. IgG and IgM antibody detection both showed high sensitivity and specificity, advocating for efficient CMV diagnosis at Khorshid Laboratory, Tehran. Conclusion: This study emphasizes the need for a quick and efficient CMV diagnostic approach in kidney transplant patients. The strong correlation between molecular and serological methods favors using the faster RT-PCR method, crucial for timely management, especially with the increasing agerelated CMV incidence. The findings strongly recommend RT-PCR integration for enhanced sensitivity in kidney transplant patients at Khorshid Laboratory, Tehran. [ABSTRACT FROM AUTHOR]

Cytomegalovirus (CMV)-seropositive adults have large T cell responses to a wide range of CMV proteins; these responses have been associated with chronic inflammation and frailty in people with or without HIV infection. We analyzed the relationships between chronic HIV infection, frailty, and the breadth and polyfunctionality of CD4 and CD8 T cell responses to CMV. Peripheral blood mononuclear cells from 42 men (20 without HIV and 22 with virologically suppressed HIV) in the Multicenter AIDS Cohort Study (MACS) were stimulated with peptide pools spanning 19 CMV open reading frames (ORFs). As measured by flow cytometry and intracellular cytokine staining for IFN-γ, TNF-α, and IL-2, CD8 T cells from men with HIV responded to significant ly more CMV ORFs than those from men without HIV. This was primarily due to a broader response to ORFs that are expressed during the late phase of CMV replication. The number of ORFs to which a participant's T cells responded was positively correlated with the sum of all that individual's T cell responses; these correlations were weaker in men with than without HIV. Polyfunctional CMV-specific CD4 responses (production of more than one cytokine) were significantly lower in men with than without HIV. Frailty status did not substantially affect the breadth or magnitude of the CMV-specific T cell responses. These results suggest that immune control of CMV infection is affected more by chronic HIV infection than by frailty. The differences between men with and without HIV were similar to those reported between young and older adults without HIV. [ABSTRACT FROM AUTHOR]

Three-dimensional chromatin control of eukaryotic transcription is pivotal for regulating gene expression. This additional layer of epigenetic regulation is also utilized by DNA viruses, including herpesviruses. Dynamic, spatial genomic organization often involves looping of chromatin anchored by host-encoded CCCTC-binding factor (CTCF) and other factors, which control crosstalk between promoters and enhancers. Herein, we review the contribution of CTCF-mediated looping in regulating transcription during herpesvirus infection, with a specific focus on the betaherpesvirus, human cytomegalovirus (HCMV). [ABSTRACT FROM AUTHOR]