Search Results (986)

Recombinant AAV (rAAV) vectors are increasingly favored for gene therapy due to their useful features of vectorology, such as transfection of dividing and nondividing cells, the presence of tissue-specific serotypes, and biosafety considerations. This study investigates the impact of commonly used therapeutic drugs—acetaminophen, budesonide, and simvastatin—on rAAV transduction efficiency in HEK-293 cells. Cells were transduced with an AAV mosaic vector under the control of a cytomegalovirus (CMV) promoter encoding green fluorescent protein (GFP). Transduction efficiency was assessed by qPCR and fluorescent microscopy. Analysis of functional interactions between genes potentially involved in rAAV transduction in drug-exposed cells was also performed. This study showed a clear effect of drugs on rAAV transmission. Notably, acetaminophen enhanced transduction efficiency by 9-fold, while budesonide and simvastatin showed 2-fold and 3-fold increases, respectively. The gene analysis illustrates the possible involvement of genes related to cell membranes in the potentiation of rAAV transduction induced by the drugs under investigation. Attention should be paid to S100A8, which is a common drug-modified gene for drugs showing anti-inflammatory effects (budesonide and simvastatin), demonstrating an interaction with the gene encoding the receptor for AAV (HGFR). This study underscores the significance of assessing rAAV pharmacokinetics/pharmacodynamics (PKs/PDs) and drug–gene therapy interactions in optimizing gene therapy protocols. Full article

Background/Objectives: Human cytomegalovirus (HCMV) is the most frequent cause of congenital infections. The HCMV-specific T-cell response in primary infection may help define reliable correlates of immune protection in pregnancy. In this study, the antigen-specific T-cell response against different HCMV proteins (IE-1, pp65, gB, gHgLpUL128L) was investigated in pregnant women with primary infection and in control subjects with remote infection to identify possible components of a vaccine. Methods: Blood samples from 35 pregnant women with HCMV primary infection and 30 HCMV-seropositive healthy adult subjects with remote infection were tested. The antigen-specific T-cell response was measured using cytokine intracellular staining after stimulation with IE-1, pp65, gB and gHgLpUL128L peptides pool. Results: The pp65-specific CD4⁺ T-cell response was higher in pregnant women with HCMV primary infection at the late time point and in control subjects with remote infection, while the pregnant women at the early time point showed a higher gB-specific CD8⁺ T-cell response. Regarding the CD4⁺ and CD8⁺ T-cell phenotypes, we observed that HCMV-specific CD4⁺ and CD8⁺ T cells expressing CD45RA⁺ remained constant in pregnant women with primary infection at the early and late time points and in subjects with remote infection, while HCMV-specific CD4⁺ and CD8⁺ T cells expressing IL-7R⁺ or producing IL-2 were higher in control subjects with remote infection than in pregnant women with HCMV primary infection. Conclusions: The T-cell response was higher against gB in the early phase of infection and against pp65 in the late phase. Therefore, these proteins should be taken into consideration as candidates for a vaccine. Full article

Background: Pathological reactivation of latent Cytomegalovirus (CMV) is triggered by inflammation and immunosuppression; both present in the pathogenesis and treatment of Inflammatory Bowel Disease (IBD). Whether CMV reactivation is associated with escalating medical therapy, further hospital admissions, or worse clinical outcomes remains controversial. This study aimed to follow up IBD patients with an index episode of CMV colitis and analyse the clinical outcomes. Methods: A retrospective study of patients with IBD treated for CMV colitis was completed. The outcome results were collected at 6-month and 12-month time points after the first episode of CMV colitis. A total of 13 patients with Ulcerative Colitis and 1 with Crohn’s Disease were included. Results: CMV colitis recurrence occurred in 29% of patients at 12 months. A total of 43% of patients had changed their biologic dose at 6 months and 29% had escalated their biologic dose at 12 months. At 12 months, 36% of patients had been re-hospitalised, including three colectomies. Disease remission was only achieved by 29% of patients at 12 months. Conclusions: IBD patients with CMV colitis have substantial rates of re-hospitalisation, failed medical therapy, and colectomy. These risks may be greater at <6 months from an index episode of CMV colitis. Full article

Secondary envelopment of the human cytomegalovirus (HCMV) is a critical but not well-understood process that takes place at the cytoplasmic viral assembly complex (cVAC) where nucleocapsids acquire their envelope by budding into cellular membranes containing viral glycoproteins. Previous studies presented controversial results regarding the composition of the viral envelope, suggesting trans-Golgi and endosomal origins, as well as intersections with the exosomal and endocytic pathways. Here, we investigated the role of endocytic membranes for the secondary envelopment of HCMV by using wheat germ agglutinin (WGA) pulse labeling to label glycoproteins at the plasma membrane and to follow their trafficking during HCMV infection by light microscopy and transmission electron microscopy (TEM). WGA labeled different membrane compartments within the cVAC, including early endosomes, multivesicular bodies, trans-Golgi, and recycling endosomes. Furthermore, TEM analysis showed that almost 90% of capsids undergoing secondary envelopment and 50% of enveloped capsids were WGA-positive within 90 min. Our data reveal extensive remodeling of the endocytic compartment in the late stage of HCMV infection, where the endocytic compartment provides an optimized environment for virion morphogenesis and serves as the primary membrane source for secondary envelopment. Furthermore, we show that secondary envelopment is a rapid process in which endocytosed membranes are transported from the plasma membrane to the cVAC within minutes to be utilized by capsids for envelopment. Full article

(1) Background: Intrinsic defense mechanisms are pivotal host strategies to restrict viruses already at early stages of their infection. Here, we addressed the question of how the autophagy receptor sequestome 1 (SQSTM1/p62, hereafter referred to as p62) interferes with human cytomegalovirus (HCMV) infection. (2) Methods: CRISPR/Cas9-mediated genome editing, mass spectrometry and the expression of p62 phosphovariants from recombinant HCMVs were used to address the role of p62 during infection. (3) Results: The knockout of p62 resulted in an increased release of HCMV progeny. Mass spectrometry revealed an interaction of p62 with cellular proteins required for nucleocytoplasmic transport. Phosphoproteomics further revealed that p62 is hyperphosphorylated at position S272 in HCMV-infected cells. Phosphorylated p62 showed enhanced nuclear retention, which is concordant with enhanced interaction with viral proteins relevant for genome replication and nuclear capsid egress. This modification led to reduced HCMV progeny release compared to a non-phosphorylated version of p62. (4) Conclusions: p62 is a restriction factor for HCMV replication. The activity of the receptor appears to be regulated by phosphorylation at position S272, leading to enhanced nuclear localization, viral protein degradation and impaired progeny production. Full article

Human Herpesviruses (HHVs) play a significant role in neurological diseases such as encephalitis and meningitis, adding significant morbidity. This study aims to retrospectively analyze the effect of HHVs on patients with neurological symptoms, focusing on the Herpesviridae family’s contributions to central nervous system (CNS) infections. Methods: This retrospective cohort study included 895 patients suspected of viral CNS infections, utilizing molecular diagnosis via qPCR to identify HHVs in cerebrospinal fluid (CSF) samples. This was conducted at a reference tertiary care hospital for infectious diseases in the western Brazilian Amazon from January 2015 to December 2022, focusing on the Herpesviridae family’s clinical repercussions and of Cytomegalovirus in CNS infections. Results: The findings revealed that 7.5% of the analyzed samples tested positive for HHVs, with Human Cytomegalovirus (HCMV) and Epstein–Barr Virus (EBV) being the most prevalent. A significant association was found between HHVs and neurological diseases such as encephalitis and meningitis, especially among people living with HIV/AIDS (PLWHA), highlighting the opportunistic nature of these viruses. The study underscores the critical role of CSF analysis in diagnosing CNS infections and the complexity of managing these infections in HIV patients due to their immunocompromised status. Conclusions: The results emphasize the need for comprehensive diagnostic approaches and tailored treatment strategies for CNS infections in immunocompromised individuals. The study calls for ongoing research and advancements in clinical practice to improve patient outcomes facing CNS infections, particularly those caused by HHVs. Full article

Cytomegalovirus (CMV) retinitis is the most common eye disease associated with CMV infection in immunocompromised individuals. The CMVR may initially be asymptomatic; however, relatively mild vitreous inflammation at the onset may be an important differential point from other diseases in HIV patients. Fundus photography, CD4 T-cell count, and telemedicine could be used to screen and monitor the high-risk population, particularly in resource-limited regions. Retinitis generally starts in the peripheral retina and advances toward the posterior pole, which could develop to the characteristic “pizza pie” appearance marked by central retinal necrosis and intraretinal hemorrhage. CMVR causes vision loss if left untreated, and early antiviral therapy significantly reduces the risk of vision loss. Alongside traditional antiviral treatments, immunotherapies including CMV-specific adoptive T-cell therapy and CMV immunoglobulin (CMVIG) are emerging as promising treatment options due to their favorable tolerability and reduced mortality. This review comprehensively examines CMV retinitis, encompassing the clinical features, differential diagnosis, laboratory tests, and updated treatment strategies to inform clinical management. Full article

Cytomegalovirus infection contributes to 10–30% of congenital hearing loss in children. Vertebrate peripheral auditory organs include the outer, middle, and inner ear. Their development is regulated by multiple signaling pathways. However, most ear diseases due to viral infections are due to congenital infections and reactivation and affect healthy adults to a lesser extent. This may be due to the fact that viral infections affect signaling pathways that are important for the development of peripheral hearing organs. Therefore, an in-depth understanding of the relationship between viral infections and the signaling pathways involved in the development of peripheral hearing organs is important for the prevention and treatment of ear diseases. In this review, we summarize the effects of viruses on signaling pathways and signaling molecules in the development of peripheral auditory organs. Full article

Introduction: Cytomegalovirus (CMV) infection is present in a latent state in 70–90% of the immunocompetent population, and its reactivation might be triggered by inflammatory conditions such as post-COVID multisystem inflammatory syndrome (MIS-C) or by immunosuppression induced by steroids. The aim of this paper was to highlight the unexpected complications associated with SARS-CoV-2 infection that require a complex clinical approach for accurate diagnosis. Materials and Methods: We present the case of a 4-year-old male patient who, during an initially favorable course of PIMS, experienced symptoms of respiratory failure. Results: The patient initially presented with clinical and paraclinical signs of PIMS with cardiac involvement, for which high-dose corticosteroid therapy was initiated, followed by gradual tapering, along with immunoglobulins, anticoagulants, antiplatelet agents, and symptomatic treatment. After 10 days of favorable progress, the patient’s general condition deteriorated, showing tachypnea, desaturation, and a ground-glass appearance on thoracic CT. Negative inflammatory markers and favorable cardiac lesion evolution ruled out MIS-C relapse. The presence of anti-CMV IgM antibodies and viral DNA in the blood confirmed acute CMV infection, likely triggered by prior severe-acute-respiratory-syndrome-related coronavirus 2 (SARS-CoV-2) infection and secondary immunosuppression due to steroids. Non-specific immunomodulatory treatment was initiated but led to worsening of pulmonary lesions, prompting the initiation of specific antiviral treatment with ganciclovir, resulting in rapid clinical and imaging improvement. Conclusions: CMV infection can be reactivated by immunosuppression induced by corticosteroid therapy for MIS-C and may require specific etiological treatment. Full article

Cytomegalovirus causes the most common congenital infection worldwide. With most infants asymptomatic at birth, the few affected may present with variable clinical scenarios, from isolated hearing loss to severe neurologic impairment. Public health interventions include all actions at the health system, community, and individual levels that aim at reducing the burden of congenital Cytomegalovirus. This review examines the literature on maternal and neonatal screening programs in light of current evidence for treatment and the development of vaccines against Cytomegalovirus. Potential biases and benefits of these interventions are outlined, with the objective of increasing awareness about the problem and providing readers with data and critical tools to participate in this ongoing debate. Full article

A 2.5-month-old girl admitted for failure to thrive and severe pancytopenia was diagnosed with methylmalonic acidemia (MMA) secondary to transcobalamin II deficiency, an inborn error of vitamin B12 metabolism. Opportunistic Cytomegalovirus and Pneumocystis jirovecii pneumonia led to severe acute respiratory distress syndrome (ARDS) and immune reconstitution inflammatory syndrome (IRIS) after treatment initiation with vitamin B12 supplementation. In children with interstitial pneumonia-related ARDS, normal lymphocyte count should not delay invasive procedures required to document opportunistic infections. MMA can be associated with underlying lymphocyte dysfunction and vitamin B12 supplementation can fully reverse the associated immunodeficiency. IRIS may appear in highly treatment-responsive forms of pancytopenia in children and prompt treatment of dysregulated inflammation with high-dose corticosteroids should be initiated. Full article

Herpesviral protein kinases, such as the therapy-relevant pUL97 of human cytomegalovirus (HCMV), are important for viral replication efficiency as well as pathogenesis, and represent key antiviral drug targets. HCMV pUL97 is a viral cyclin-dependent kinase (CDK) ortholog, as it shares functional and structural properties with human CDKs. Recently, the formation of vCDK/pUL97–cyclin complexes and the phosphorylation of a variety of viral and cellular substrate proteins has been demonstrated. Genetic mapping and structural modeling approaches helped to define two pUL97 interfaces, IF1 and IF2, responsible for cyclin binding. In particular, the regulatory importance of interactions between vCDK/pUL97 and host cyclins as well as CDKs has been highlighted, both as determinants of virus replication and as a novel drug-targeting option. This aspect was substantiated by the finding that virus replication was impaired upon cyclin type H knock-down, and that such host-directed interference also affected viruses resistant to existing therapies. Beyond the formation of binary interactive complexes, a ternary pUL97–cyclin H–CDK7 complex has also been described, and in light of this, an experimental trans-stimulation of CDK7 activity by pUL97 appeared crucial for virus–host coregulation. In accordance with this understanding, several novel antiviral targeting options have emerged. These include kinase inhibitors directed to pUL97, to host CDKs, and to the pUL97–cyclin H interactive complexes. Importantly, a statistically significant drug synergy has recently been reported for antiviral treatment schemes using combinations of pharmacologically relevant CDK7 and vCDK/pUL97 inhibitors, including maribavir. Combined, such findings provide increased options for anti-HCMV control. This review focuses on regulatory interactions of vCDK/pUL97 with the host cyclin–CDK apparatus, and it addresses the functional relevance of these key effector complexes for viral replication and pathogenesis. On this basis, novel strategies of antiviral drug targeting are defined. Full article

Ganciclovir (GCV) and its prodrug valganciclovir (VGCV) are antiviral medications primarily used to treat infections caused by cytomegalovirus (CMV), particularly in immunocompromised individuals such as solid organ transplant (SOT) recipients. Therapy with GCV is associated with significant side effects, including bone marrow suppression. Therefore, therapeutic drug monitoring (TDM) is mandatory for an appropriate balance between subtherapeutic and toxic drug levels. This study aimed to develop and validate three novel methods based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for GCV determination in serum (reference methodology), dried serum spots (DSS), and VAMS-Mitra™ devices. The methods were optimized and validated in the 0.1–25 mg/L calibration range. The obtained results fulfilled the EMA acceptance criteria for bioanalytical method validation. Assessment of DSS and VAMS techniques extended GCV stability to serum for up to a minimum of 49 days (at room temperature, with desiccant). Developed methods were effectively evaluated using 80 clinical serum samples from pediatric renal transplant recipients. Obtained samples were used for DSS, and dried serum VAMS samples were manually generated in the laboratory. The results of GCV determination using serum-, DSS- and VAMS-LC-MS/MS methods were compared using regression analysis and bias evaluation. The conducted statistical analysis confirmed the interchangeability between developed assays. The DSS and VAMS samples are more accessible and stable during storage, transport and shipment than classic serum samples. Full article

Protein expression is regulated through multiple mechanisms, including post-translational modifications (PTMs), which can alter protein structure, stability, localization, and function. Among these, citrullination stands out due to its ability to convert arginine residues into citrulline, altering protein charge and mass. This modification is catalyzed by calcium-dependent protein arginine deiminases (PADs), enzymes implicated in various inflammatory diseases. We have recently shown that human cytomegalovirus (HCMV) and herpes simplex virus type 1 (HSV-1) exploit these enzymes to enhance their replication capabilities. Although the role of PADs in HCMV and HSV-1 infections is well documented, their involvement in HSV-2 infection has not yet been thoroughly investigated. Here, we demonstrate that HSV-2 manipulates the overall protein citrullination profile by activating three PAD isoforms: PAD2, PAD3, and PAD4. However, as previously observed during HSV-1 infection, PAD3 is the most significantly upregulated isoform, both at the mRNA and protein levels. Consistently, we demonstrate that inhibiting PAD3, either through the specific inhibitor CAY10727 or via CRISPR/Cas9-mediated gene silencing, markedly reduces HSV-2 replication and viral protein expression. Lastly, we show that CAY10727 displays an IC50 value of 0.3 μM, which is extremely close to what was previously observed for HSV-1. Overall, our findings highlight the crucial role of PAD3 in the life cycle of HSV-2 and suggest that the targeted inhibition of PAD3 may represent a promising approach for treating HSV-2 infections, especially in cases resistant to existing antiviral therapies. Full article

Viruses are obligate intracellular pathogens as their replication depends on the metabolism of the host cell. The induction of cellular suicide, known as programmed cell death (PCD), has the potential to hinder viral replication and act as a first line of defense against viral pathogens. Apoptosis, necroptosis, and pyroptosis are three important PCD modalities. Different signaling pathways are involved in their execution, and they also differ in their ability to cause inflammation. Cytomegaloviruses (CMV), beta-herpesviruses with large double-stranded DNA genomes, encode a great variety of immune evasion genes, including several cell death suppressors. While CMV inhibitors of apoptosis and necroptosis have been known and studied for years, the first pyroptosis inhibitor has been identified and characterized only recently. Here, we describe how human and murine CMV interfere with apoptosis, necroptosis, and pyroptosis signaling pathways. We also discuss the importance of the different PCD forms and their viral inhibitors for the containment of viral replication and spread in vivo. Full article