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A DNA tumor virus called Epstein-Barr virus (EBV) is the cause of 1-2% of human cancers. EBV-associated carcinogenesis is caused by a persistent latent infection. The shortage of antiviral medications or vaccinations to control the virus led to a significant percentage of critically sickness individuals needing to be hospitalized. In the absence of an effective vaccine and approved drug, there is an immediate need for treatments that can combat EBV infection. Epstein Barr nuclear antigen 1 (EBNA1) is continually expressed in all malignancies linked to EBV; it is a desirable target for curative interference. Herein, natural product compounds from the Nuclei of Bioassays, Ecophysiology and Biosynthesis of Natural Products (NuBBE) database were mined to identify potent EBNA1 inhibitors. The performance of the molecular docking technique was initially assessed in expecting the ligand-target binding pose according to the available experimental data. On the basis of the estimated docking protocol, the NuBBE database was virtually screened toward the EBNA1 protein, and the natural compounds with binding scores less than KWG (calc. − 7. 8 kcal/mol) were subjected to molecular dynamics (MD) simulations followed by binding energy (Δ G binding ) calculation using MM/GBSA approach. Based on binding energy computations, NuBBE1460 revealed superior Δ G binding with a value of − 3 6. 2 kcal/mol, compared to KWG (calc. − 3 2. 4 kcal/mol). Post-MD analyses displayed a high steadiness of NuBBE1460 within the EBNA1 protein binding pocket. Furthermore, the physicochemical, pharmacokinetic and toxicity features of the identified compound were predicted, demonstrating high degrees of its oral bioavailability. The energetical and geometrical properties of NuBBE1460 were calculated using the DFT method. Conclusively, this study offers NuBBE1460 obtained from natural sources as a lead EBNA1 inhibitor for future investigation and development as a therapeutic for EBV. NuBBE database was virtually screened as potent EBNA1 inhibitors using in-silico calculations. Compared to KWG, a reference inhibitor, NuBBE1460 exhibited better binding affinity against EBNA1. NuBBE1460 demonstrated promising stability in complex with EBNA1 and unveiled good oral bioavailability. [ABSTRACT FROM AUTHOR]

Autoimmune polyendocrinopathy‐candidiasis‐ectodermal dystrophy (APECED) is an inborn error of immunity affecting both multiple endocrine organs and susceptibility to candidiasis, each with an autoimmune basis. Recently, high titer neutralizing anti‐type I interferon (IFN) autoantibodies have been linked with increased severity of SARS‐CoV‐2 and varicella zoster virus infections in APECED patients. Examining immunity against cytomegalovirus (CMV), we found a higher prevalence of anti‐CMV IgG antibodies in patients with APECED (N = 19) than in 44 healthy controls (90% vs 64%, p = 0.04); the similar difference in their IgG levels did not achieve significance (95 ± 74 vs 64 ± 35 IU/mL, ns.). In contrast, the frequency of CMV‐specific T cells was lower (804 ± 718/million vs 1591 ± 972/million PBMC p = 0.03). We saw no correlations between levels of anti‐CMV IgG and anti‐IFN antibodies in APECED patients or in a separate cohort of patients with thymoma (n = 70), over 60% of whom also had anti‐IFN antibodies. Our results suggest a dysregulated response to CMV in APECED patients and highlight immunodeficiency to viral infections as part of the disease spectrum. [ABSTRACT FROM AUTHOR]

Current medical research suggests that latently infected cells are the primary source of the virus's resistance to elimination. Moreover, these cells can participate in cell–cell transmission. Human immunodeficiency virus type 1 (HIV-1) can transmit to CD4 + T cells by three transmission modes, cell-free, latent cell–cell and active cell–cell. Incorporating the effect of latent infection, weakened humoral and CTL responses as well as three transmission modes, we investigate two generalized HIV-1 dynamics models. Three general incidence functions are used to represent the three viral transmission modes. Our proposed models extend and generalize many viral infection models presented in the virology literature. We begin by demonstrating the solutions' boundedness and nonnegativity which guarantee the model's wellposedness. We calculate the model's basic reproduction ratio (ℜ 0). We establish that the model admits two steady-states, namely, virus-free steady-state and virus-persistence steady-state. Through application of Lyapunov's approach and LaSalle's invariance principle, we demonstrate the global stability of each state-state. For two special forms of the general incidence functions, Holling type-II incidence and Crowley–Martin incidence, we provide numerical simulations to validate our theoretical findings. We illustrate how time delay and weakened adaptive immunity affect HIV-1 dynamics. More specifically, numerical data support our theoretical conclusions on the stability of steady-states. To demonstrate the impact of the parameter values on ℜ 0 , we examine the sensitivity analysis. We have demonstrated that each of the three viral transmission modes adds to ℜ 0 , and that ℜ 0 would be underestimated if any one of them were ignored. This might lead to inadequate medication effectiveness that aims to remove the viruses from the body. The effects of weakened adaptive immunity and time delay on HIV-1 progression are examined. As per our findings, reduced adaptive immunity plays a crucial role in the proliferation of the infection. Weaken adaptive immunity can lead to the acquired immune deficiency syndrome (AIDS) and give a chance for opportunistic infections. We showed that ℜ 0 fall as a function of both medication efficacy and delay parameter. If a model with time delays is used, fewer treatment efficacies will be required to maintain the system at the virus-free steady-state and eradicate HIV-1 from the body. Our study's findings can help us better understand HIV-1 dynamics in the host and can also guide the development of new pharmacological therapies. [ABSTRACT FROM AUTHOR]

Viral infection leads to heterogeneous cellular outcomes ranging from refractory to abortive and fully productive states. Single cell transcriptomics enables a high resolution view of these distinct post-infection states. Here, we have interrogated the host-pathogen dynamics following reactivation of Epstein-Barr virus (EBV). While benign in most people, EBV is responsible for infectious mononucleosis, up to 2% of human cancers, and is a trigger for the development of multiple sclerosis. Following latency establishment in B cells, EBV reactivates and is shed in saliva to enable infection of new hosts. Beyond its importance for transmission, the lytic cycle is also implicated in EBV-associated oncogenesis. Conversely, induction of lytic reactivation in latent EBV-positive tumors presents a novel therapeutic opportunity. Therefore, defining the dynamics and heterogeneity of EBV lytic reactivation is a high priority to better understand pathogenesis and therapeutic potential. In this study, we applied single-cell techniques to analyze diverse fate trajectories during lytic reactivation in three B cell models. Consistent with prior work, we find that cell cycle and MYC expression correlate with cells refractory to lytic reactivation. We further found that lytic induction yields a continuum from abortive to complete reactivation. Abortive lytic cells upregulate NFκB and IRF3 pathway target genes, while cells that proceed through the full lytic cycle exhibit unexpected expression of genes associated with cellular reprogramming. Distinct subpopulations of lytic cells further displayed variable profiles for transcripts known to escape virus-mediated host shutoff. These data reveal previously unknown and promiscuous outcomes of lytic reactivation with broad implications for viral replication and EBV-associated oncogenesis. Author summary: Viral infections profoundly alter host cell biological programming in ways that potentiate disease. Epstein-Barr virus (EBV) is a particularly prevalent human pathogen associated with diverse cancers and several autoimmune disorders. EBV predominantly establishes latent infection in B cells and can promote B cell malignancies through functions of well-characterized latent oncoproteins. Aspects of the viral lytic cycle also clearly contribute to EBV-associated diseases, although pathologic roles of lytic reactivation are incompletely understood. Here we use single-cell techniques to examine cellular responses to EBV lytic reactivation in multiple B cell models. Consistent with prior studies, reactivation from latency is incomplete (abortive) in some cells and successful in others. Abortive and full lytic trajectories exhibit distinct biological responses that each may promote pathogenesis and reinforce bimodal latent-lytic control. Intriguingly, a portion on cells that proceed through the lytic cycle exhibits unexpected and striking expression of genes associated with cellular reprogramming, pluripotency, and self-renewal. Collectively, this study provides a valuable resource to understand diverse host-virus dynamics and fates during viral reactivation and identifies multiple modes of EBV lytic pathogenesis to investigate in future research. [ABSTRACT FROM AUTHOR]

Background: Immune reconstitution inflammatory syndrome (IRIS) is an inflammatory reaction that occurs in HIV/AIDS patients after antiretroviral therapy (ART) initiation. Along with immune system recovery, IRIS can overreact to existing infections or latent pathogens, causing symptoms that mimic those infections. Few studies elucidated the clinical features and prognosis of Talaromycosis marneffei (TSM)-associated IRIS in HIV/AIDS patients. The aim of our study was to evaluate the incidence, clinical characteristics, and prognosis of TSM-associated IRIS by retrospectively analyzing the clinical data of HIV/AIDS patients with TSM. Methodology/Principal findings: A total of 224 HIV/AIDS inpatients with TSM were enrolled, aged between 19 and 81 years. Among them, 86.6% were male and 13.4% were female, of which 24 (10.7%) patients developed IRIS. In IRIS group, the median time from ART initiation to IRIS occurrence was 9.0 days (IQR, 5.0–16.8 days), with 87.5% (21/24) occurring within 2 weeks. Primary clinical manifestations included recurrent fever and exacerbation of pulmonary infection. At the onset of IRIS, 54.2% (13/24) patients were treated with intravenous dexamethasone, and 12.5% (5/24) patients were treated with oral prednisone for 1–3 weeks. No significant differences in baseline characteristics or ART regimens were observed between IRIS and non-IRIS groups; however, patients in IRIS group had higher levels of CRP, CD4+ count, and CD4+/CD8+ ratio than non-IRIS group (equivalent time point: 1–2 weeks after ART initiation) at IRIS onset. The IRIS group exhibited longer hospital stays and higher readmission rates, but equivalent mortality rates compared with non-IRIS group. Conclusions/Significance: IRIS is a common complication in HIV/AIDS patients with TSM, often occurring within 2 weeks after ART initiation and exhibiting more pronounced immune reconstitution. The occurrence of IRIS significantly extended the hospitalization duration and increased the rate of readmission but had no influence on the mortality rate. Author summary: Immune reconstitution inflammatory syndrome (IRIS) is an inflammatory reaction that occurs in HIV/AIDS patients after antiretroviral therapy (ART) initiation. Along with immune system recovery, IRIS can overreact to existing infections or latent pathogens, causing symptoms that mimic those infections. The clinical characteristics of IRIS depend on the causative pathogen. Talaromycosis marneffei (TSM) is one of the common opportunistic infections in HIV/AIDS patients, and often presents a disseminated form of infection, affecting multiple organs throughout the body. However, few reports on TSM-associated IRIS lead to challenges in clinical management. In this study, we carried out a retrospective analysis of TSM-associated IRIS, elucidated the occurrence and clinical features of TSM-associated IRIS, and compared the laboratory examination data and outcomes in TSM patients with or without IRIS. This study aims to review clinical data from HIV/AIDS patients with TSM to assess the frequency, features, and outcomes of TSM-associated IRIS, to improve understanding of the condition, and to facilitate clinical treatment effectively. [ABSTRACT FROM AUTHOR]

Background: Efforts to eradicate tuberculosis (TB) are threatened by diabetes mellitus (DM), which confers a 3-fold increase in the risk of TB disease. The changes in the memory phenotypes and functional profiles of Mycobacterium tuberculosis (Mtb)-specific T cells in latent TB infection (LTBI)-DM participants remain poorly characterised. We, therefore, assessed the effect of DM on T-cell phenotype and function in LTBI and DM clinical groups. Methods: We compared the memory phenotypes and function profiles of Mtb-specific CD4+ and CD8+ T cells among participants with LTBI-DM (n=21), LTBI-only (n=17) and DM-only (n=16). Peripheral blood mononuclear cells (PBMCs) were stimulated with early secretory antigenic 6 kDa (ESAT-6) and culture filtrate protein 10 (CFP-10) peptide pools or phytohemagglutinin (PHA). The memory phenotypes (CCR7/CD45RA), and functional profiles (HLA-DR, PD-1, CD107a, IFN-γ, IL-2, TNF, IL-13, IL-17A) of Mtb-specific CD4+ and CD8+ T cells were characterised by flow cytometry. Results: Naive CD4+ T cells were significantly decreased in the LTBI-DM compared to the LTBI-only participants [0.47 (0.34-0.69) vs 0.91 (0.59-1.05); (p<0.001)]. Similarly, CD8+ HLA-DR expression was significantly decreased in LTBI-DM compared to LTBI-only participants [0.26 (0.19-0.33) vs 0.52 (0.400.64); (p<0.0001)], whereas CD4+ and CD8+ PD-1 expression was significantly upregulated in the LTBI-DM compared to the LTBI-only participants [0.61 (0.530.77) vs 0.19 (0.10-0.28); (p<0.0001) and 0.41 (0.37-0.56) vs 0.29 (0.17-0.42); (p=0.007)] respectively. CD4+ and CD8+ IFN-γ production was significantly decreased in the LTBI-DM compared to the LTBI-only participants [0.28 (0.19-0.38) vs 0.39 (0.25-0.53); (p=0.030) and 0.36 (0.27-0.49) vs 0.55 (0.41-0.88); (p = 0.016)] respectively. CD4+ TNF and CD8+ IL-17A production were significantly decreased in participants with LTBI-DM compared to those with LTBI-only [0.38 (0.33-0.50) vs 0.62 (0.46-0.87); (p=0.004) and 0.29 (0.16-0.42) vs 0.47 (0.29-0.52); (0.017)] respectively. LTBI-DM participants had significantly lower dual-functional (IFN-γ+IL-2+ and IL-2+TNF+) and mono-functional (IFN-γ+ and TNF+) CD4+ responses than LTBI-only participants. LTBI-DM participants had significantly decreased dual-functional (IFN-γ+IL-2+, IFN-γ+ TNF+ and IL-2+TNF+) and mono-functional (IFN-γ+, IL-2+ and TNF+) central and effector memory CD4+ responses compared to LTBI-only participants. Conclusion: Type 2 DM impairs the memory phenotypes and functional profiles of Mtb-specific CD4+ and CD8+ T cells, potentially indicating underlying immunopathology towards increased active TB disease risk. [ABSTRACT FROM AUTHOR]

The immunization of mice with the sterile culture medium supernatants of Mycobacterium tuberculosis (Mtb) H37Rv permitted the production of several monoclonal antibodies (mAbs) specific for secreted and/or released antigens. Two mAbs bound and immunoprecipitated an 80-kDa protein that was identified by mass spectrometry as Rv1133c, the methionine synthase MetE. The protein MetE is ubiquitous among prokaryota and shows a significant sequence homology in many bacteria. We produced both the full-length recombinant MetE and its N-terminal fragment, whose sequence is more conserved among mycobacteria, to select mAbs recognizing an Mtb-specific region of MetE. Finally, we produced and selected eight mAbs that specifically detect the MetE protein in the supernatant and cell lysate of Mtb and BCG, but not other bacteria such as non-tuberculous mycobacteria (NTM), Streptococcus pneumoniae, Staphylococcus aureus, Acinetobacter baumanii, or Escherichia coli. Taking advantage of our mAbs, we studied (i) the vitamin B12 dependence for the synthesis of MetE in Mtb and NTM and (ii) the kinetics of MetE production and secretion in supernatants during the in vitro reproduced replicative, dormant, and resuscitation cycle of Mtb. Our data demonstrate that dormant Mtb, which are assumed to be prevalent in latent infections, as well as NTM do not produce and secrete MetE. Results indicate an unexpected specificity for Mtb of our anti-MetE mAbs and encourage the use of rMetE and our mAbs as tools for the immunodiagnosis of TB and its stages. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is a devastating and rapidly spreading disease. Despite years of scientific research and numerous efforts, it is still a major and resurgent health problem worldwide, with high mortality rates. Added to the concern is that TB persists as a latent infection, an occult face of TB, that becomes a potential reservoir for active tuberculosis. Since latent TB‐infected patients may eventually advance to the active form of TB, an accurate diagnosis and effective treatment of latent tuberculosis are essential for TB control. Latent tuberculosis infection (LTBI) treatment is a prominent component of TB control in low‐prevalence countries like the United States; however, its implication in high‐incidence countries like India is still challenging. Therefore, the present study aimed to evaluate the impact of implementing diagnosis and treatment of LTBI in high‐incidence countries using a mathematical model‐based approach. Through our model, we predicted the incidence rate based on the current treatment regimen in India for the year 2035, which is one of the milestones of WHO for a substantial reduction in TB incidence. We observed demographic variability in the effects of various parameters on the TB incidence rate. Finally, we formulated the putative treatment strategies to reduce the TB burden in high‐incidence scenarios. Further, we estimated the impact of these proposed treatment strategies on the drug‐resistant population in high‐incidence scenarios. The model predictions suggested molding the current treatment strategies and focused implementation of LTBI diagnosis and treatment in high‐incidence scenarios. [ABSTRACT FROM AUTHOR]

Pseudorabies virus (PRV) can establish lifelong latent infection in peripheral nervous ganglion, and persistent infections in peripheral blood lymphocytes. Establishing an infection in the lymphocytes does not only enable the PRV to escape host immune surveillance but pass through the placental barrier, leading to fetal death and abortion. Due to the pathogenicity of the PRV, it poses a huge challenge in its prevention and control. The PRV escapes host immunity through downregulation of swine leukocyte antigen class I (SLA I) molecules on infected cells. However, data on the molecular mechanisms of the SLA I suppression remains scant. Here, in order to verify the effect of candidate proteins PRV pUL44 and pUS6 on PRV immune escape related molecules SLA I and peptide loading complex (PLC), we detected the expression of SLA I and PLC components after expressing PRV pUL44 and pUS6. The effects of pUS6 and pUL44 on SLA I and PLC were analyzed by qRT-PCR and Western blot at mRNA and protein level, respectively. Cells expressing pUS6 or pUL44 genes showed a significantly suppressed expression of surface and total SLA I molecules. In addition, unlike UL44, the US6 gene was shown to downregulate the transporter associated with antigen processing 1 (TAP1), TAP2 and Tapasin molecules. The results show that PRV pUS6 may participate in virus immune escape by directly regulating the SLA I, TAP dimer and Tapasin molecules, thus blocking the transportation of TAP-bound peptides to the ER to bind SLA I molecules. We provide a theoretical basis on the mechanism of TAP mediated immune escape by the PRV. [ABSTRACT FROM AUTHOR]

Background: Epstein-Barr virus (EBV) infection has been closely linked to the development of various types of cancer. EB nuclear antigen 1 binding protein 2 (EBNA1BP2) is a crucial molecule for stable isolation of EBV in latent infection. However, the role of EBNA1BP2 in multiple tumor types is remains unclear. In this study, we comprehensively analyzed the functional characteristics of EBNA1BP2 and investigate its potential as a prognostic biomarker in pan-cancer. Methods: We utilized data from TCGA (The Cancer Genome Atlas) and GEO (Gene Expression Omnibus) databases and employed various bioinformatics analysis tools, including TIMER2.0, HPA, GEPIA2.0, PrognoScan, cBioPortal, CancerSEA, and BioGRID to explore the expression pattern, prognostic value, immune infiltration, and methylation level of EBNA1BP2 in pan-cancer. Additionally, we conducted enrichment analysis of genes associated with EBNA1BP2 to identify potential biological functions and pathways. Results: Our analysis revealed that EBNA1BP2 expression was significantly higher in tumor tissues compared to tumor-adjacent tissues. We observed that lower expression of EBNA1BP2 in adrenocortical carcinoma (ACC), brain lower grade glioma (LGG), sarcoma (SARC), and uterine carcinosarcoma (UCS) was significantly associated with improved overall survival (OS) and disease-free survival (DFS). Furthermore, the promoter methylation level of EBNA1BP2 was downregulated in the majority of cancer types. At the single-cell level, EBNA1BP2 was found to be positively correlated with cell cycle and DNA repair processes, while negatively correlated with hypoxia. Additionally, EBNA1BP2 was associated with the infiltration of immune cells such as B cells, cancer-associated fibroblast cells, and CD8+ T cells. Gene enrichment analysis indicated that EBNA1BP2 was mainly involved in nucleoplasm and RNA binding pathways. Conclusion: Our findings suggest that EBNA1BP2 may serve as a potential prognostic biomarker for survival in pan-cancer. Further experimental studies are needed to validate these findings and explore the underlying mechanisms by which EBNA1BP2 contributes to tumorigenesis. [ABSTRACT FROM AUTHOR]

Background: The reactivation of tuberculosis (TB) among kidney transplant (KT) recipients in an endemic area is of general concern. However, the epidemiology of latent TB infection (LTBI) status and its dynamic change responses have not been explored. Methods: Between September 2020 and August 2021, a prospective study was conducted to investigate the status of LTBI in KT recipients who received a 9-month isoniazid universal prophylaxis. This status was measured using the interferon-gamma release assay (IGRA) with T-SPOT.TB before transplant, as well as at one month and nine months post-transplant. Results: Ninety-one KT recipients had a mean (SD) age of 45 (11) years, and 41% were female. Sixty-eight (75%) patients received a deceased donor allograft, and eighty-six (91%) patients received induction immunosuppressive therapy. The IGRA results were positive, borderline, negative, and indeterminate in 14 (15.4%), 6 (6.6%), 64 (70.3%), and 7 (7.8%) patients, respectively. Among 84 evaluable patients, 20 (23.8%) KT recipients were defined as having LTBI. Older age was significantly associated with LTBI (OR 1.06 [95% CI 1.01–1.12], p = 0.03). Among the 77 KT recipients who completed monitoring, 55 had negative IGRA results. Three (5.4%) KT recipients had conversion post-transplant. One of them developed pulmonary TB at 1 week after the transplant. Among the 13 patients with positive results, 8 (61.5%) remained positive, 1 (7.7%) had an indeterminate result at 1-month post-transplant and subsequently tested positive at 9 months post-transplant, and 4 (30.8%) experienced reversion to negative results throughout the study. Conclusions: In a high TB-endemic area, one-quarter of KT recipients were reported to have LTBI, and the dynamic change of IGRA response in KT recipients is plausible post-transplant. [ABSTRACT FROM AUTHOR]

HSV-1 genomes are rapidly heterochromatinized following entry by host cells to limit viral gene expression. Efficient HSV-1 genome replication requires mechanisms that de-repress chromatin associated with the viral genome. CCCTC-binding factors, or CTCF insulators play both silencing and activating roles in cellular transcriptional regulation. Importantly, the HSV-1 genome encodes several CTCF insulators that flank IE genes, implying that individual HSV-1 encoded CTCF insulators regulate IE transcription during all stages of the HSV-1 life cycle. We previously reported that the HSV-1 encoded CTCF insulator located downstream of the LAT (CTRL2) controlled IE gene silencing during latency. To further characterize the role of this insulator during the lytic infection we leveraged a ΔCTRL2 recombinant virus to show that there was a genome replication defect that stemmed from decreased IE gene expression in fibroblasts and epithelial cells at early times following initiation of infection. Further experiments indicated that the defect in gene expression resulted from chromatin inaccessibility in the absence of the insulator. To elucidate how chromatin accessibility was altered in the absence of the CTRL2 insulator, we showed that enrichment of Alpha-thalassemia/mental retardation, X-linked chromatin remodeler (ATRX), and the histone variant H3.3, both of which are known for their roles in maintaining repressive histone markers on the HSV-1 viral genome were increased on IE regions of HSV-1. Finally, both H3K27me3 and H3K9me3 repressive histone marks remained enriched by 4 hours post infection in the absence of the CTRL2 insulator, confirming that the CTRL2 insulator is required for de-repression of IE genes of viral genomes. To our knowledge these are the first data that show that a specific CTCF insulator in the HSV-1 genome (CTRL2) regulates chromatin accessibility during the lytic infection. Author summary: Herpes Simplex Virus 1 (HSV-1) remains a significant lifelong human pathogen. Over 70% of adults worldwide are infected with HSV-1 and following the establishment of a persistent latent infection in the peripheral nervous system, the virus can undergo reactivation. These reactivation episodes can result in recurrence of viral infection in the cornea and repeated episodes of recurrence can result in corneal blindness. HSV-1 remains a leading infectious cause of blindness worldwide. On a molecular level, both the incoming lytic virus and the latent viral genome are chromatinized for the purposes of silencing the virus. Viral gene expression in both lytic and reactivated HSV-1 requires the de-repression of chromatin on the viral genome but it remains unclear whether distinct transcriptional mechanisms regulate viral gene expression during these two stages of the viral life cycle. CCCTC-binding factors, also known as CTCF insulators, are essential regulators of chromatin structure and gene expression in mammalian cells and these cellular insulator elements also play vital regulatory roles in transcriptional control of all classes of herpesviruses as well. Existing research on CTCF and herpesviruses have been done in the context of herpesvirus latency but considering role of CTCF insulators in organizing chromatin architecture, it is logical that these important elements also play a role in either the initial chromatinization of virus, the de-repression of chromatin on incoming viruses so that transcription can occur- or both. Here we show that the CTRL2 insulator is required for de-repression of IE genes during the lytic infection and that the insulator has distinct and divergent functions during the lytic and latent stages of the viral lifecycle. To our knowledge these are the first data that show that a specific CTCF insulator in HSV-1 regulates chromatin accessibility in a site-specific manner. Understanding these mechanisms is particularly important for future drug discovery where cellular elements contributing to the de-repression of viral chromatin might be targeted. [ABSTRACT FROM AUTHOR]

HIV establishes long-term latent infection in memory CD4+ T cells and also establishes sustained long-term productive infection in macrophages, especially in the central nervous system (CNS). To better understand how HIV sustains infection in macrophages, we performed RNAseq analysis after infection of human monocytederived macrophages (MDMs) with the brain-derived HIV-1 strain YU2 and compared this with acute infection of CD4+ T cells. HIV infection in MDM and CD4+ T cells altered many gene transcripts, but with few overlaps between these different cell types. We found interferon pathways upregulated in both MDM and CD4+ T cells, but with different gene signatures. The interferon-stimulated gene RSAD2/Viperin was among the most upregulated genes following HIV infection in MDMs, but not in CD4+ T cells. RSAD2/Viperin was induced early after infection with various HIV strains, was sustained over time, and remained elevated in established MDM infection even if new rounds of infection were blocked by antiretroviral treatment. Immunofluorescence microscopy revealed that RSAD2/Viperin was induced in HIV-infected cells, as well as in some uninfected neighboring cells. Knockdown of RSAD2/Viperin following the establishment of infection in MDMs reduced the production of HIV transcripts and viral p24 antigen. This correlated with the reduction in the number of multinucleated giant cells, and changes in the HIV DNA and chromatin structure, including an increased DNA copy number and loss of nucleosomes and histone modifications at the long terminal repeat (LTR). RNAseq transcriptomic analysis of RSAD2/Viperin knockdown during HIV infection of MDMs revealed the activation of interferon alpha/beta and gamma pathways and the inactivation of Rho GTPase pathways. Taken together, these results suggest that RSAD2/Viperin supports the sustained infection in macrophages, potentially through mechanisms involving the alteration of the LTR chromatin structure and the interferon response. [ABSTRACT FROM AUTHOR]

Published studies have generated compelling results indicating that type I IFN modulates function of HSV-1 latency-associated transcript (LAT). One member of type I IFN is IFNα2A also called Roferon-A). IFNα2A has been used in monotherapy or in combination therapy with other drugs to treat viral infections and different kinds of cancer in humans. The goal of this study was to determine whether the absence of IFNα2A affects primary and latent infections in ocularly infected mice. Therefore, we generated a mouse strain lacking IFNα2A expression (IFNα2A-/-). Ocular HSV-1 replication, IFN and immune cell expressions on days 3 and 5 post infection (PI), as well as eye disease, survival, latency-reactivation, and T cell exhaustion were evaluated in ocularly infected IFNα2A-/- and wild type (WT) control mice. Absence of IFNα2A did not affect other members of the IFNα family but it affected IFNβ and IFNγ expressions as well as some immune cells on day 5 PI compared to WT mice. Viral replication in the eye, eye disease, and survival amongst ocularly infected IFNα2A-/- mice were similar to that of WT infected mice. The absence of IFNα2A significantly reduced the levels of latency and T cell exhaustion but not time of reactivation compared with control mice. Our results suggest that blocking IFNα2A expression may be a useful tool in reducing latency and the subsequent side effects associated with higher levels of latency. Author summary: Many viruses have evolved strategies to circumvent the IFN system, including (i) inhibition of IFN production; (ii) blocking of downstream signaling events that occur after cytokine-receptor binding; and (iii) inhibition of the functions of proteins, which are induced by IFN, including apoptotic proteins. The interferons (IFNs) are of considerable interest in the control of HSV-1 infection due to their rapid generation in response to viral infection and their antiviral activities. Type I interferons, which includes interferon alpha (IFNα), are a family of cytokines important for control of viral infections. There are at least 14 IFNα genes in mouse, amongst which includes the gene encoding IFNα2A that play an important role in human studies. The mechanisms by which HSV-1 interferes with type I IFN responses during primary infection, establishment of latency and reactivation are not fully understood. Thus, to evaluate the importance of IFNα2A on HSV-1 infectivity, we generated IFNα2A knockout mice. The absence of IFNα2A significantly reduced latency and T cell exhaustion, but not virus reactivation. [ABSTRACT FROM AUTHOR]

This article explores the challenges of determining the viability of infectious agents in tissue samples. It discusses various methods used in histopathology, such as staining techniques and immunohistochemistry, to assess viability. The article also mentions the potential use of mRNA analysis to indicate active replication of infectious agents. The author acknowledges the limitations of current techniques and suggests that nucleic acid amplification from formalin-fixed, paraffin-embedded samples could provide a more accurate assessment of viability. The article emphasizes the need for improved methods to determine the viability of infectious agents in tissue samples and calls for further research in this area. [Extracted from the article]

The coexistence of diabetes mellitus (DM) and tuberculosis (TB) presents a significant global burden, with DM being recognized as a major risk factor for TB. This review comprehensively analyzes the immunological aspects of DM‐TB comorbidity, shedding light on the impact of DM on TB pathogenesis and immune responses. It reveals that high blood glucose levels in TB patients contribute to reduced innate immune cell count, compromised phagocytic function, and delayed antigen presentation. These factors ultimately impair the clearance of Mycobacterium tuberculosis (MTB) and delay adaptive immune responses. With the interaction between TB and DM, there is an increase in inflammation and elevated secretion of pro‐inflammatory cytokines by immune cells. This exacerbates the inflammatory response and contributes to poor treatment outcomes in TB. Moreover, the review explores the effects of DM on TB prevention, diagnosis, and treatment. It highlights how poor glycemic control, insulin resistance (IR), DM complications, and genetic factors increase the risk of MTB infection in individuals with DM. Additionally, DM‐related immune suppression adversely affects the sensitivity of traditional diagnostic tests for TB, potentially resulting in underdiagnosis and delayed intervention. To mitigate the burden of TB in DM patients, the review emphasizes the need for further research on the mechanisms underlying DM reactivation in latent TB infection (LTBI). It shows how important it is to find and treat LTBI in DM patients as soon as possible and suggests looking into biomarkers that are specific to DM to make diagnosis more accurate. [ABSTRACT FROM AUTHOR]

The Epstein–Barr virus (EBV) nuclear antigen 1 (EBNA1) is critically involved in maintaining episomes during latent infection and promoting tumorigenesis. The development of an epitope‐specific monoclonal antibody (mAb) for EBNA1 holds great promise due to its high affinity and specificity, offering a new and innovative approach for the treatment of EBV‐related diseases. In this proof‐of‐concept study, we employed a structure‐based design strategy to create three unique immunogens specifically targeting the DNA binding state of the EBNA1 DBD. By immunizing mice, we successfully generated a mAb, named 5E2‐12, which selectively targets the DNA binding interface of EBNA1. The 5E2‐12 mAb effectively disrupts the interaction between EBNA1 and DNA binding, resulting in reduced proliferation of EBV‐positive cells and inhibition of xenograft tumor growth in both cellular assays and mouse tumor models. These findings open up new avenues for the development of innovative biological macromolecular drugs that specifically target EBNA1 and provide potential for clinical therapy options for early‐stage EBV‐positive tumors. The epitope‐specific mAb approach demonstrates novelty and innovation in tackling EBV‐related diseases and may have broad implications for precision medicine strategies in the field of viral‐associated cancers. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Preventive management of tuberculosis in liver transplantation (LT) is challenging due to difficulties in detecting and treating latent tuberculosis infection (LTBI). The aim of this study was to analyze the safety and efficacy of a screening strategy for LTBI with the inclusion of moxifloxacin as treatment.We performed a retrospective single‐center study of all LTs performed between 2016 and 2019 with a minimum 4‐year follow‐up and a standardized protocol for the evaluation of LTBI.Pretransplant LTBI screening was performed in 191/218 (87.6%) patients, and LTBI was diagnosed in 27.2% of them. Treatment for LTBI was administered to 71.2% of the patients and included moxifloxacin in 75.6% of the cases. After a median follow‐up of 1628 days, no cases of active tuberculosis occurred among moxifloxacin‐treated patients. The incidence of Clostridioides difficile (0.46 vs. 0.38 episodes/1000 transplant‐days; p =  .8) and multidrug‐resistant gram‐negative bacilli infection (0 vs. 0.7 episodes per 1000 transplant‐days; p =  .08) were not significantly higher in comparison to patients who did not receive moxifloxacin.A preventive strategy based on systematic LTBI screening and moxifloxacin treatment before LT in positive cases appears safe and effective in preventing the development of tuberculosis in LT recipients. However, our findings are limited by a small sample size; thus, larger studies are required to validate our observations. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis (TB) is one of the most widespread infectious diseases worldwide, typically persisting in the body as a latent TB infection (LTBI). Patients with type 2 diabetes have an increased risk of LTBI progressing to active TB. Therefore, this study determined the prevalence and predictors of LTBI and assessed the agreement between tuberculin skin test (TST) and interferon-gamma release assay (IGRA) in diagnosing LTBI among type 2 diabetics in Sana'a city, Yemen. Methods: A cross-sectional study was conducted among 150 type 2 diabetics in private health facilities in Sana'a in 2023. Data about demographics, diabetes-related characteristics, and potential risk factors for LTBI were collected using a structured questionnaire. Patients were then screened for LTBI using TST and IGRA. Univariate analysis was used to identify LTBI-associated risk factors, and multivariable binary logistic regression was used to identify independent predictors of LTBI. The agreement between TST and IGRA for diagnosing LTBI was assessed using Cohen's kappa coefficient (κ). Results: LTBI was prevalent among 29.3% of type 2 diabetics using both types of tests (25.3% with IGRA and 21.3% with TST). Male gender was an independent predictor of LTBI (AOR = 4.4, 95% confidence interval: 1.30–15.08; P = 0.018). However, being employed (AOR = 0.3, 95% CI: 0.09–0.75; P = 0.013) and longer duration since diabetes diagnosis (AOR = 0.3, 95% CI: 0.12–0.98; P = 0.046) were identified as predictors of lower LTBI risk. The agreement between TST and IGRA for the diagnosis of LTBI was 88%, with a good and statistically significant agreement between the two test types (κ = 0.670; P < 0.001). Conclusions: LTBI is common among type 2 diabetics seeking medical care in Sana'a city, with about one-third of them possibly being latently infected. A higher LTBI risk can be predicted among males, while a lower risk can be predicted among those employed or being diagnosed with diabetes for at least five years. The TST shows good agreement with IGRA in diagnosing LTBI among type 2 diabetics, supporting its continued use as a cost-effective and easily accessible test for diagnosing LTBI in the country. [ABSTRACT FROM AUTHOR]

Objectives: Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is frequently preceded by infections. The underlying pathomechanism, however, remains poorly understood. Here, we present the clinical data of two MOGAD patients with concurrent syphilis infection and investigate the reactivity of patient-derived antibodies to MOG and Treponema pallidum (T. pallidum). Methods: Longitudinal serumsamples and soluble immunoglobulins in single B cell supernatants were measured for MOG reactivity by a live cell-based assay. Reactivity against T. pallidum was assessed by enzyme-linked immunosorbent assay. Results: The two patients presented MOGAD and concurrent latent syphilis infection, manifesting as cervical myelitis and unilateral optic neuritis, respectively. The first patient had been living with HIV on antiretroviral therapy, and the second was concomitantly diagnosed with chronic hepatitis B infection. Upon screening of B cell supernatants, we identified reactivity to MOG or T. pallidum. Notably, one B cell showed reactivity to both antigens. Discussion: The coexistence of MOGAD diagnoses and latent syphilis, alongside the identification of antibody reactivity to MOG and T. pallidum, underscores the potential pathomechanistic link between syphilis infection and subsequent autoimmune neuroinflammation. Cross-reactivity between MOG and T. pallidum antibodies remains to be validated on a molecular level, and further characterization of infectious triggers associated with MOGAD is needed. [ABSTRACT FROM AUTHOR]

Gene drives are genetic modifications designed to propagate efficiently through a population. Most applications rely on homologous recombination during sexual reproduction in diploid organisms such as insects, but we recently developed a gene drive in herpesviruses that relies on co-infection of cells by wild-type and engineered viruses. Here, we report on a viral gene drive against human herpes simplex virus 1 (HSV-1) and show that it propagates efficiently in cell culture and during HSV-1 infection in mice. We describe high levels of co-infection and gene drive-mediated recombination in neuronal tissues during herpes encephalitis as the infection progresses from the site of inoculation to the peripheral and central nervous systems. In addition, we show evidence that a superinfecting gene drive virus could recombine with wild-type viruses during latent infection. These findings indicate that HSV-1 achieves high rates of co-infection and recombination during viral infection, a phenomenon that is currently underappreciated. Overall, this study shows that a viral gene drive could spread in vivo during HSV-1 infection, paving the way toward therapeutic applications. Gene drives are genetic modifications designed to propagate efficiently through a population. Here, the authors develop a viral gene drive against herpes simplex virus 1 (HSV-1) and show that it propagates efficiently during HSV-1 infection in mice. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) remains one of the leading causes of death among infectious diseases, with 10.6 million new cases and 1.3 million deaths reported in 2022, according to the most recent WHO report. Early studies have shown an expansion of γδ T cells following TB infection in both experimental models and humans, indicating their abundance among lung lymphocytes and suggesting a role in protective immune responses against Mycobacterium tuberculosis (M. tuberculosis) infection. In this study, we hypothesized that distinct subsets of γδ T cells are associated with either protection against or disease progression in TB. To explore this, we applied large-scale scRNA-seq and bulk RNA-seq data integration to define the phenotypic and molecular characteristics of peripheral blood γδ T cells. Our analysis identified five unique γδ T subclusters, each with distinct functional profiles. Notably, we identified a unique cluster significantly enriched in the TCR signaling pathway, with high CD81 expression as a conserved marker. This distinct molecular signature suggests a specialized role for this cluster in immune signaling and regulation of immune response against M. tuberculosis. Flow cytometry confirmed our in silico results, showing that the mean fluorescence intensity (MFI) values of CD81 expression on γδ T cells were significantly increased in individuals with latent TB infection (TBI) compared to those with active TB (ATB). This finding underscores the importance of CD81 and its associated signaling mechanisms in modulating the activity and function of γδ T cells under TBI conditions, providing insights into potential therapeutic targets for TB management. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is caused by infection with the bacterial pathogen Mycobacterium tuberculosis (M.tb) in the respiratory tract. There was an estimated 10.6 million people newly diagnosed with TB, and there were approximately 1.3 million deaths caused by TB in 2022. Although the global prevalence of TB has remained high for decades and is an annual leading cause of death attributed to infectious diseases, only one vaccine, Bacillus Calmette--Gueérin (BCG), has been approved so far to prevent/attenuate TB disease. Correlates of protection or immunological mechanisms that are needed to control M.tb remain unknown. The protective role of antibodies after BCG vaccination has also remained largely unclear; however, recent studies have provided evidence for their involvement in protection against disease, as biomarkers for the state of infection, and as potential predictors of outcomes. Interestingly, the antibodies generated post-vaccination with BCG are linked to the activation of innate immune cascades, providing further evidence that antibody effector functions are critical for protection against respiratory pathogens such as M.tb. In this review, we aim to provide current knowledge of antibody application in TB diagnosis, prevention, and treatment. Particularly, this review will focus on 1) The role of antibodies in preventing M.tb infections through preventing Mtb adherence to epithelium, antibody-mediated phagocytosis, and antibody-mediated cellular cytotoxicity; 2) The M.tb-directed antibody response generated after vaccination and how humoral profiles with different glycosylation patterns of these antibodies are linked with protection against the disease state; and 3) How antibody-mediated immunity against M.tb can be further explored as early diagnosis biomarkers and different detection methods to combat the global M.tb burden. Broadening the paradigm of differentiated antibody profiling and antibody-based detection during TB disease progression offers new directions for diagnosis, treatment, and preventative strategies. This approach involves linking the aforementioned humoral responses with the disease state, progression, and clearance. [ABSTRACT FROM AUTHOR]

Apremilast is a relatively new oral treatment for psoriasis, which reduces expression of pro‐inflammatory factors, including tumour necrosis factor‐α (TNFα), critical to the immune control of Mycobacterium tuberculosis infection. In randomised controlled trials (RCTs) for apremilast no new cases of active tuberculosis (TB) were identified, thus, screening for latent TB infection (LTBI) is not currently recommended prior to apremilast initiation. We describe a case of M.tuberculosis reactivation shortly after commencement of apremilast for psoriasis. We are recommending clinicians perform LTBI risk assessment in all patients, and appropriate LTBI screening in select populations prior to apremilast initiation. [ABSTRACT FROM AUTHOR]

Background: To effectively control tuberculosis (TB), it is crucial to distinguish between active TB disease and latent TB infection (LTBI) to provide appropriate treatment. However, no such tests are currently available. Immune responses associated with active TB and LTBI are dynamic and exhibit distinct patterns. Comparing these differences is crucial for developing new diagnostic methods and understanding the etiology of TB. This study aimed to investigate the relationship between pro- and anti-inflammatory CD4+ cytokine production following stimulation with two types of latency-associated Mycobacterium tuberculosis (M.tb) antigens to allow differentiation between active TB and LTBI. Methods: Cryopreserved PBMCs from patients with active TB disease or LTBI were stimulated overnight with replication-related antigen [ESAT-6/CFP-10 (E/C)] or two latency-associated antigens [heparin-binding hemagglutinin (HBHA) and alpha-crystallin-like protein (Acr)]. Responses were analyzed using multiparameter flow cytometry: active TB disease (n=15), LTBI (n=15) and ELISA: active TB disease (n=26) or LTBI (n=27). Results: CD4+ central memory T cells (Tcm) specific to E/C and CD4+ effector memory T cells specific to Acr and HBHA were higher in LTBI than inTB patients. IFN-γ+Tcm and IL-17+ Tem cells was higher in the LTBI group (p= 0.012 and p=0.029 respectively), but IL-10+ Tcm was higher in the active TB group (p= 0.029) following HBHA stimulation. Additionally, following stimulation with HBHA, IL-10 production from CD4+ T cells was significantly elevated in patients with active TB compared to those with LTBI (p= 0.0038), while CD4+ T cell production of IL-17 and IFN-γ was significantly elevated in LTBI compared to active TB (p= 0.0076, p< 0.0001, respectively). HBHA also induced more CCR6 + IL-17+CD4Tcells and IL-17+FoxP3+CD25+CD4Tcells in LTBI than in TB patients (P=0.026 and P=0.04, respectively). HBHA also induced higher levels of IFN-γ+IL-10+CD4+ T cells in patients with active TB (Pp=0.03) and higher levels of IFN-γ+IL-17+ CD4+ T cells in those with LTBI (p=0.04). HBHA-specific cytokine production measured using ELISA showed higher levels of IFN-γ in participants with LTBI (P=0.004) and higher levels of IL-10 in those with active TB (P=0.04). Conclusion: Stimulation with HBHA and measurement of CD4+ T cell production of IFN-γ, IL-10, and IL-17 could potentially differentiate active TB from LTBI. The characteristics of cytokine-expressing cells induced by HBHA also differed between participants with active TB and LTBI. [ABSTRACT FROM AUTHOR]

Despite extensive knowledge on phage resistance at bacterium level, the resistance of bacterial communities is still not well-understood. Given its ubiquity, it is essential to understand resistance at the community level. We performed quantitative investigations on the dynamics of phage infection in Klebsiella pneumoniae biofilms. We found that the biofilms quickly developed resistance and resumed growth. Instead of mutations, the resistance was caused by unassembled phage tail fibers released by the phage-lysed bacteria. The tail fibers degraded the bacterial capsule essential for infection and induced spreading of capsule loss in the biofilm, and tuning tail fiber and capsule levels altered the resistance. Latent infections sustained in the biofilm despite resistance, allowing stable phage-bacteria coexistence. Last, we showed that the resistance exposed vulnerabilities in the biofilm. Our findings indicate that phage lysate plays important roles in shaping phage-biofilm interactions and open more dimensions for the rational design of strategies to counter bacteria with phage. [ABSTRACT FROM AUTHOR]

Immunosenescence refers to the age-related progressive decline of immune function contributing to the increased susceptibility to infectious diseases in older people. Neurocryptococcosis, an infectious disease of central nervous system (CNS) caused by Cryptococcus neoformans (C. Neoformans) and C. gattii, has been observed with increased frequency in aged people, as result of the reactivation of a latent infection or community acquisition. These opportunistic microorganisms belonging to kingdom of fungi are capable of surviving and replicating within macrophages. Typically, cryptococcus is expelled by vomocytosis, a non-lytic expulsive mechanism also promoted by interferon (IFN)-I, or by cell lysis. However, whereas in a first phase cryptococcal vomocytosis leads to a latent asymptomatic infection confined to the lung, an enhancement in vomocytosis, promoted by IFN-I overproduction, can be deleterious, leading the fungus to reach the blood streamand invade the CNS. Cryptococcus may not be easy to diagnose in older individuals and, if not timely treated, could be potentially lethal. Therefore, this review aims to elucidate the putative causes of the increased incidence of cryptococcal CNS infection in older people discussing in depth the mechanisms of immunosenscence potentially able to predispose to neurocryptococcosis, laying the foundations for future research. A deepest understanding of this relationship could provide new ways to improve the prevention and recognition of neurocryptococcosis in aged frail people, in order to quickly manage pharmacological interventions and to adopt further preventive measures able to reduce the main risk factors. [ABSTRACT FROM AUTHOR]

Background: Adult T-cell leukemia/lymphoma (ATL) is caused by human T-cell leukemia virus type 1 (HTLV-1) after a long latent infection. HTLV-1 induces the indolent or aggressive type of leukemia in 5% of HTLV-1 carriers. ATL, especially the aggressive type, is resistant to multi-agent chemotherapy. The indolent type often progresses to the aggressive type. Even in the most indolent-type cases, that is, smoldering ATL, the average survival time is 55.0 months. Case Presentation: Five patients with ATL were followed up for their clinical course after amplified natural killer cell (ANK) therapy. Four patients who received ANK therapy as first-line therapy achieved complete remission and showed long-term survival without aggressive conversion or relapse for more than 5 years. One patient was treated with multiagent chemotherapy due to acute exacerbation but relapsed 2 months later. She was subsequently treated with radiation and ANK therapy and survived for more than 6 years. Furthermore, ANK therapy enhanced the immune function of ATL patients to a level higher than that of normal individuals. Conclusions: ANK therapy has great potential as first-line treatment for ATL. [ABSTRACT FROM AUTHOR]

Equid alphaherpesvirus 1 (EHV-1) has been linked to the emergence of neurological disorders, with the horse racing industry experiencing significant impacts from outbreaks of equine herpesvirus myeloencephalopathy (EHM). Building robust immune memory before pathogen exposure enables rapid recognition and elimination, preventing infection. This is crucial for effectively managing EHV-1. Removing neuropathogenic factors and immune evasion genes to develop live attenuated vaccines appears to be a successful strategy for EHV-1 vaccines. We created mutant viruses without ORF38 and ORF37/38 and validated their neuropathogenicity and immunogenicity in hamsters. The ∆ORF38 strain caused brain tissue damage at high doses, whereas the ∆ORF37/38 strain did not. Dexamethasone was used to confirm latent herpesvirus infection and reactivation. Dexamethasone injection increased viral DNA load in the brains of hamsters infected with the parental and ∆ORF38 strains, but not in those infected with the ∆ORF37/38 strain. Immunizing hamsters intranasally with the ∆ORF37/38 strain as a live vaccine produced a stronger immune response compared to the ∆ORF38 strain at the same dose. The hamsters demonstrated effective protection against a lethal challenge with the parental strain. This suggests that the deletion of ORF37/38 may effectively inhibit latent viral infection, reduce the neuropathogenicity of EHV-1, and induce a protective immune response. [ABSTRACT FROM AUTHOR]

Kaposi's sarcoma-associated herpesvirus (KSHV) is a cancer-causing virus that establishes life-long infection. KSHV is implicated in the etiology of Kaposi's sarcoma, and a number of rare hematopoietic malignancies. The present study focuses on the KSHV open reading frame 20 (ORF20), a member of the conserved herpesvirus UL24 protein family containing five conserved homology domains and a conserved PD-(D/E)XK putative endonuclease motif, whose nuclease function has not been established to date. ORF20 encodes three co-linear protein isoforms, full length, intermediate, and short, though their differential functions are unknown. In an effort to determine the role of ORF20 during KSHV infection, we generated a recombinant ORF20-Null KSHV genome, which fails to express all three ORF20 isoforms. This genome was reconstituted in iSLK cells to establish a latent infection, which resulted in an accelerated transcription of viral mRNAs, an earlier accumulation of viral lytic proteins, an increase in the quantity of viral DNA copies, and a significant decrease in viral yield upon lytic reactivation. This was accompanied by early cell death of cells infected with the ORF20-Null virus. Functional complementation of the ORF20-Null mutant with the short ORF20 isoform rescued KSHV production, whereas its endonuclease mutant form failed to enhance lytic reactivation. Complementation with the short isoform further revealed a decrease in cell death as compared with ORF20-Null virus. Finally, expression of IL6 and CXCL8, previously shown to be affected by the hCMV UL24 homolog, was relatively low upon reactivation of cells infected with the ORF20-Null virus. These findings suggest that ORF20 protein, with its putative endonuclease motif, promotes coordinated lytic reactivation for increased infectious particle production. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the contribution of genetic factors, i.e., the level of expression and polymorphisms of Toll-like receptors (TLR), to the susceptibility of latent tuberculosis infection in a Russian cohort of individuals infected with HIV. The patients (n = 317) with confirmed HIV infection were divided into two groups according to the results of the STANDARD E TB-Feron test: 63 cases with a latent TB infection and 274 controls without LTBI. Total DNA and RNA were isolated from whole-blood samples. SNP genotyping and expression levels of five TLR genes (TLR1, TLR2, TLR4, TLR6, and TLR8) were determined by means of real-time PCR. There were no significant differences in the expression levels of the TLRs between the case and control groups. In addition, we did not observe any significant association between the analyzed SNPs and the susceptibility of Latent tuberculosis infection (LTBI) in patients with HIV. However, patients from an entire cohort with the rs4986790-GG (TLR4) and rs5743708-GG (TLR2) genotypes were characterized by lower CD4 T-cell counts compared to carriers of alternative alleles. Moreover, we found a significant risk of a hazardous drop in the CD4 T-cell count below 350 cells/mm3 associated with the rs4986790-G (TLR4) allele. Latent tuberculosis infection in individuals infected with HIV does not significantly modify the level of TLR gene expression. [ABSTRACT FROM AUTHOR]

Viruses sense cellular states and environmental signals by recruiting host transcription factors to cis -regulatory elements (CREs) in viral genomes. Viral CREs act as signal integration hubs that impart specificity to viral gene regulation. Viral CREs are highly evolvable due to their high mutation rate and ability to rapidly change sensing mechanisms, affecting infection spread and patient outcomes. Latent viral infections can be treated by targeting viral CREs for reactivation or permanent silencing. To withstand a hostile cellular environment and replicate, viruses must sense, interpret, and respond to many internal and external cues. Retroviruses and DNA viruses can intercept these cues impinging on host transcription factors via cis -regulatory elements (CREs) in viral genomes, allowing them to sense and coordinate context-specific responses to varied signals. Here, we explore the characteristics of viral CREs, the classes of signals and host transcription factors that regulate them, and how this informs outcomes of viral replication, immune evasion, and latency. We propose that viral CREs constitute central hubs for signal integration from multiple pathways and that sequence variation between viral isolates can rapidly rewire sensing mechanisms, contributing to the variability observed in patient outcomes. [ABSTRACT FROM AUTHOR]

Herpes simplex virus 1 (HSV-1) is an alpha herpesvirus that infects a majority of the world population. The mechanisms and cellular host factors involved in the intracellular transport and exocytosis of HSV-1 particles are not fully understood. To elucidate these late steps in the replication cycle, we developed a live-cell fluorescence microscopy assay of HSV-1 virion intracellular trafficking and exocytosis. This method allows us to track individual virus particles and identify the precise moment and location of particle exocytosis using a pH-sensitive reporter. We show that HSV-1 uses the host cell’s post-Golgi secretory pathway during egress. The small GTPase, Rab6, binds to nascent secretory vesicles at the trans-Golgi network and plays important, but non-essential, roles in vesicle traffic and exocytosis at the plasma membrane, therefore making it a useful marker of the Golgi and post-Golgi secretory pathway. We show that HSV-1 particles colocalize with Rab6a in the region of the Golgi, cotraffic with Rab6a to the cell periphery, and undergo exocytosis from Rab6a vesicles. Consistent with previous reports, we find that HSV-1 particles accumulate at preferential egress sites in infected cells. The secretory pathway mediates this preferential/polarized egress, since Rab6a vesicles accumulate near the plasma membrane similarly in uninfected cells. These data suggest that, following particle envelopment, HSV-1 egress follows a pre-existing cellular secretory pathway to exit infected cells rather than novel, virus-induced mechanisms. IMPORTANCE Herpes simplex virus 1 (HSV-1) infects a majority of people. It establishes a life-long latent infection and occasionally reactivates, typically causing characteristic oral or genital lesions. Rarely in healthy natural hosts, but more commonly in zoonotic infections and in elderly, newborn, or immunocompromised patients, HSV-1 can cause severe herpes encephalitis. The precise cellular mechanisms used by HSV-1 remain an important area of research. In particular, the egress pathways that newly assembled virus particles use to exit from infected cells are unclear. In this study, we used fluorescence microscopy to visualize individual virus particles exiting from cells and found that HSV-1 particles use the pre-existing cellular secretory pathway. [ABSTRACT FROM AUTHOR]

Biological therapies have revolutionized medical treatment by targeting the key mediators or receptors involved in inflammatory responses, thereby effectively suppressing inflammation and achieving beneficial outcomes. They are more advanced than conventional therapies using corticosteroids and immunosuppressants, offering effective solutions for autoimmune diseases, cancer, transplant rejection, and various infectious diseases, including coronavirus disease 2019. Although they exert low immunosuppressive effects, biological therapies can reactivate specific biological targets associated with infections. This review summarizes the currently available biological therapies and discusses their immunosuppressive mechanisms and clinical applications, highlighting the variations in the types and frequencies of infection recurrence induced by different biological agents. Additionally, this review describes the risk factors associated with various biological agents, thus aiding clinicians in selecting the most appropriate biological therapy. [ABSTRACT FROM AUTHOR]

This is the first report of the occurrence of blueberry virus L (BlVL) in Japan and the complete nucleotide sequence of a Japanese isolate. BlVL was detected using reverse transcription-polymerase chain reaction in 35 of 52 highbush blueberry shrubs at Iwate University Research Farm, Japan, and in aphids (Aphis gossypii) on a BlVL-infected blueberry shrub. In the aphid transmission test of BlVL, the aphids transmitted the virus to uninfected blueberry bushes. No symptoms were observed in shrubs infected with the virus by aphid inoculation or by graft inoculation, suggesting that BlVL causes latent infection in highbush blueberry. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, over one thousand papers were published on "Susceptible- Exposed-Infectious-Removed" (SEIR) epidemic computational models. The English word "exposed" in its vernacular and public health usage means a state of having been in contact with an infectious individual, but not necessarily infected. In contrast, the term "exposed" in SEIR modeling usage typically stands for a state of already being infected but not yet being infectious to others, a state more properly termed "latently infected." In public health language, "exposed" means possibly infected, yet in SEIR modeling language, "exposed" means already infected. This paper retraces the conceptual and mathematical origins of this terminological disconnect and concludes that epidemic modelers should consider using the "SLIR" notational short-hand (L for Latent) instead of SEIR. [ABSTRACT FROM AUTHOR]

The prevalence of Tuberculosis (TB) serves as a pivotal metric, reflecting the TB burden within a specific demographic. It quantifies the number of individuals affected by either active TB disease or latent TB (LTBI). Such data is crucial for assessing the efficacy of TB control interventions and determining the demand for diagnostic and treatment services. This study aims to consolidate data on TB infection prevalence in Saudi Arabia from existing literature. Additionally, we stratify this prevalence based on age, professional involvement in healthcare, gender, and region. Our search was conducted in PubMed, Scopus, Cochrane Library, and Web of Science databases to determine relevant studies. The pooled prevalence of TB infection among the total population residing in Saudi Arabia was estimated using a random-effect meta-analysis approach and Comprehensive Meta-Analysis software. The protocol was registered in the PROSPERO International Prospective Register of Systematic Reviews, No: CRD42023400984. We included 21 studies, 11 of which were pooled in the analysis. The overall prevalence was 17%. Regarding the specific population, we found that the prevalence of TB in Saudi Arabia was 9.8% and 26.7% in the general population and the healthcare workers, respectively. Stratifying by age, the highest prevalence was observed in individuals over 50 years (33.0%), while the lowest was in the 10–19 age group (6.4%). In terms of gender, men had a higher prevalence (12.0%) compared to women (9.4%). The prevalence of TB in Riyadh was 6.4%, and 3.6% in Mecca and Medina. Among healthcare workers, nurses and physicians had a prevalence of 14.7% and 15.0%, respectively. Our study found a TB prevalence of 17.0% in Saudi Arabia, higher than the worldwide average of 12.0%. Men had a higher prevalence than women, and healthcare workers had a relatively low prevalence compared to other countries. Age was a significant risk factor, with the highest prevalence in individuals above 50 years. Standardized protocols for screening and diagnosis and targeted interventions are needed to combat TB effectively in the country. [ABSTRACT FROM AUTHOR]

BACKGROUND: Biocontrol agents (BCAs) are alternatives to synthetic fungicides with low risk to the environment and human health. Although several studies on the biocontrol of gray mold in vineyards have been performed, it is necessary to improve the usage of BCAs in fields conditions. Therefore, in the present study, BCAs were used both in calendar‐based [based on four growth stages (GSs), i.e., flowering, pre‐bunch closure, veraison, and before harvest] and predictive model‐based strategies (only when Botrytis cinerea infection risk was predicted by the model). The BCAs applied during the seasons were selected considering the grapevine GSs. Treatments performed with BCAs were compared with synthetic fungicide treatments and an untreated control. The trials were conducted in three experimental vineyards with four epidemics. To evaluate the level of gray mold control of each treatment, disease severity was assessed at harvest and the presence of latent infection was evaluated. RESULTS: The integrative use of the predictive model and BCAs provided satisfactory levels of gray mold control, with gray mold severity levels significantly lower (P < 0.001) than those of the untreated control, which had severity values (< 7%) similar to those observed with synthetic fungicides following both calendar and model‐based strategies. CONCLUSIONS: The integrative use of the predictive model and BCAs represents a valid alternative to conventional methods of gray mold control in vineyards, with more than 75% reduction in fungicide usage. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Alphaherpesviruses, including herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), and varicella-zoster virus (VZV), infect a diverse array of hosts, spanning both humans and animals. Alphaherpesviruses have developed a well-adapted relationship with their hosts through long-term evolution. Some alphaherpesviruses exhibit a typical neurotropic characteristic, which has garnered widespread attention and in-depth research. Virus latency involves the retention of viral genomes without producing infectious viruses. However, under stress, this can be reversed, resulting in lytic infection. Such reactivation events can lead to recurrent infections, manifesting as diseases like herpes labialis, genital herpes, and herpes zoster. Reactivation is a complex process influenced by both viral and host factors, and identifying how latency and reactivation work is vital to developing new antiviral therapies. Recent research highlights a complex interaction among the virus, neurons, and the immune system in regulating alphaherpesvirus latency and reactivation. Neurotropic alphaherpesviruses can breach host barriers to infect neurons, proliferate extensively within their cell bodies, and establish latent infections or spread further. Whether infecting neurons or spreading further, the virus undergoes transmission along axons or dendrites, making this process an indispensable part of the viral life cycle and a critical factor influencing the virus's invasion of the nervous system. Research on the transmission process of neurotropic alphaherpesviruses within neurons can not only deepen our understanding of the virus but can also facilitate the targeted development of corresponding vaccines. This review concentrates on the relationship between the transmission, latency, and activation of alphaherpesviruses within neurons, summarizes recent advancements in the field, and discusses how these findings can inform the design of live virus vaccines for alphaherpesviruses. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, over one thousand papers were published on “Susceptible-Exposed-Infectious-Removed” (SEIR) epidemic computational models. The English word “exposed” in its vernacular and public health usage means a state of having been in contact with an infectious individual, but not necessarily infected. In contrast, the term “exposed” in SEIR modeling usage typically stands for a state of already being infected but not yet being infectious to others, a state more properly termed “latently infected.” In public health language, “exposed” means possibly infected, yet in SEIR modeling language, “exposed” means already infected. This paper retraces the conceptual and mathematical origins of this terminological disconnect and concludes that epidemic modelers should consider using the “SLIR” notational short-hand (L for Latent) instead of SEIR.

Herpes simplex virus (HSV), an epidemic human pathogen threatening global public health, gains notoriety for its complex pathogenesis that encompasses lytic infection of mucosal cells, latent infection within neurons, and periodic reactivation. This intricate interplay, coupled with HSV's sophisticated immune evasion strategies, gives rise to various diseases, including genital lesions, neonatal encephalitis, and cancer. Despite more than 70 years of relentless research, an effective preventive or therapeutic vaccine against HSV has yet to emerge, primarily due to the limited understanding of virus-host interactions, which in turn impedes the identification of effective vaccine targets. However, HSV's unique pathological features, including its substantial genetic load capacity, high replicability, transmissibility, and neurotropism, render it a promising candidate for various applications, spanning oncolytic virotherapy, gene and immune therapies, and even as an imaging tracer in neuroscience. In this review, we comprehensively update recent breakthroughs in HSV pathogenesis and immune evasion, critically summarize the progress made in vaccine candidate development, and discuss the multifaceted applications of HSV as a biological tool. Importantly, we highlight both success and challenges, emphasizing the critical need for intensified research into HSV, with the aim of providing deeper insights that can not only advance HSV treatment strategies but also broaden its application horizons. [ABSTRACT FROM AUTHOR]

Background: Road traffic injuries (RTIs) are among the most important issues worldwide. Several studies reported that infection with the neurotropic parasite Toxoplasma gondii (T. gondii) increased the risk of car accidents. In this study, our objective was to investigate the possible associations among latent T. gondii, Cytomegalovirus (CMV), and Herpes Simplex Virus (HSV) infections with the risk of motorcycle accidents in Jahrom (Fars Province), which is a county with a high rate of motorcycle accidents in Iran. Methods: In the setting of a case-control study; 176 motorcyclist men, including 88 survivors of motorcycle accidents and 88 motorcyclist without accidents, were considered as case and control groups, respectively. Rates of latent infections with T. gondii, CMV, and HSV were assessed by an enzyme-linked immunosorbent assay (ELISA). Results: Eleven of 88 (12.5%) in the case group and 22 of 88 (25.0%) in controls were positive for anti-T. gondii IgG antibodies, this difference was statistically significant (OR = 0.42; CI: 0.19–0.95, p = 0.03). The general seroprevalence of CMV (94.3% in the case group vs. 87.5% in the control group, OR = 2.37; CI: 0.78–7.13, p = 0.12) and HSV (63.6% in the case group vs. 62.5% in the control group, OR = 1.05; CI: 0.57–1.94, p = 0.87) were not significantly different between the case and control groups. Conclusions: Although latent toxoplasmosis has been associated with traffic accidents in recent reports, we found a negative association between latent toxoplasmosis and motorcycle accidents among survivors of these accidents. As such, latent CMV and HSV infections did not differ significantly between the cases compared to the control groups. [ABSTRACT FROM AUTHOR]

Background: Human herpesvirus 6 (HHV-6) is considered a ubiquitous virus, with many countries reporting a seroprevalence of more than 80–90% among the general population. However, this virus is unique among herpesviruses in its ability to integrate into the genetic material of the host's cells. Thus, there are three ways by which HHV-6 can cause an active infection–primary infection, reactivation of a latent acquired infection, or activation of iciHHV-6 (inherited chromosomally integrated HHV-6). Whole blood quantitative polymerase chain reaction (qPCR) is very useful in distinguishing between iciHHV-6 and primary infection/reactivation. Our aim is to assess the role of HHV-6 in the aetiology of central nervous system (CNS) infections in adults and children, to describe all HHV-6-positive cases in an attempt to determine the susceptible population and to identify potential risk factors that can be linked to HHV-6 meningoencephalitis. Methods: We performed a retrospective study involving patients that were admitted to Prof. Dr. Matei Bals National Institute of Infectious Diseases, Bucharest, Romania, with a diagnosis of meningitis or encephalitis. We only selected the clinical records of patients that had a multiplex PCR Biofire® FilmArray® meningitis/encephalitis panel. Results: We report a 5% HHV-6 positivity in the cerebrospinal fluid (CSF) of patients with CNS infections tested with a commercial multiplex PCR M/E (meningitis/encephalitis) panel. Additionally, 2% to 4% of the total study population (n = 100) had active HHV-6 infections, which denotes 40 to 80% of the HHV-6-positive samples. We did not observe any statistically significant correlation between HHV-6 positivity in the CSF and variables such as age, sex, or comorbidities, including obesity, diabetes, hypertension, immunosuppression, or oncologic disease. Therefore, no risk factors could be linked with HHV-6 positivity in the CSF. Conclusions: although multiplex qualitative PCR is highly useful for providing rapid results and identifying nearly every pathogen that can cause meningitis/encephalitis, we have to be aware of this type of test's limitations. All patients with HHV-6 detectable in their CSF via a multiplex PCR test should also undergo qPCR testing from both CSF and blood to prevent over-diagnosing HHV-6 CNS infections, to avoid unnecessary antiviral treatments, and ensure the accurate identification of the true diagnosis. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is a significant global health problem. In immunocompetent individuals, the microorganism can remain in a latent, non‐contagious form, however, it may become active under conditions of immunosuppression. Tumour necrosis factor (TNF) inhibitors, which are frequently used for the management of immune‐mediated disorders like psoriasis, have been associated with a significantly increased risk of reactivating latent TB. Consequently, international guidelines recommend TB screening and preventive treatment before starting anti‐TNF therapy. These recommendations have extended to IL‐12/23, IL‐17, IL‐23 and TYK2 inhibitors under a caution principle, despite their different mechanisms of action. However, current evidence suggests that some of these agents are arguably not associated with an increased risk of TB reactivation or development of TB disease after infection, which calls for a critical reassessment of these guidelines. We have conducted a literature search evaluating the risk of TB reactivation associated with these innovative therapies, integrating findings from both randomized clinical trials and real‐world evidence. The identified evidence is limited but the low number of identified cases of reactivation with IL‐17 and IL‐23 inhibitors prompts reconsidering the need for preventive treatment for latent TB in all cases, regardless of biologic class or individual patient's risk of TB reactivation or drug toxicity. This review, along with the clinical insight of a panel of experts on behalf of the SPIN‐FRT, led to the development of these consensus recommendations for managing psoriasis treatment in patients with latent TB infection or at risk of TB infection, who are receiving or are intended to receive biologic and non‐biologic targeted therapies. These recommendations highlight the need for updates to the existing guidelines, aiming to provide a more differentiated approach that reflects the evolving landscape of psoriasis treatment and its implications for TB management. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) preventive treatment (TPT) effectively prevents the progression from TB infection to TB disease. This study explores factors associated with TPT non-completion in Cambodia using 6-years programmatic data (2018–2023) retrieved from the TB Management Information System (TB-MIS). Out of 14,262 individuals with latent TB infection (LTBI) initiated with TPT, 299 (2.1%) did not complete the treatment. Individuals aged between 15–24 and 25–34 years old were more likely to not complete the treatment compared to those aged < 5 years old, with aOR = 1.7, p = 0.034 and aOR = 2.1, p = 0.003, respectively. Individuals initiated with 3-month daily Rifampicin and Isoniazid (3RH) or with 6-month daily Isoniazid (6H) were more likely to not complete the treatment compared to those initiated with 3-month weekly Isoniazid and Rifapentine (3HP), with aOR = 2.6, p < 0.001 and aOR = 7, p < 0.001, respectively. Those who began TPT at referral hospitals were nearly twice as likely to not complete the treatment compared to those who started the treatment at health centers (aOR = 1.95, p = 0.003). To improve TPT completion, strengthen the treatment follow-up among those aged between 15 and 34 years old and initiated TPT at referral hospitals should be prioritized. The national TB program should consider 3HP the first choice of treatment. [ABSTRACT FROM AUTHOR]

Background: Grapevine Pinot gris virus (GPGV) infects grapevines worldwide and causes symptoms such as chlorotic mottling and deformations on leaves, stunted shoots and short panicles, or none of these symptoms if it appears as latent infection. So far, the consequences of GPGV infections for winegrowers are difficult to assess since important information such as plant performance at different GPGV infection levels and symptom expression are not fully clarified. Methods: In order to investigate the course of GPGV spread, annual visual evaluations and ELISA tests were conducted over 3–4 consecutive years in four GPGV-infected vineyards in southern Germany: GEM, HEC, NIM, and REI. The program PATCHY was used to analyze spatial disease patterns. Sanger sequencing was used to determine virus isolates in vines at different GPGV infection levels, to test their respective influence on symptom expression. Yield and GrapeScan (FTIR) analyses were conducted to test the impact of different GPGV infection levels and isolates on fruit quantity and quality. Results: GPGV infections significantly increased in all four vineyards (GEM 22–32%, HEC 50–99%, NIM 83–90%, REI 56–76%) with significant spreading patterns across and along rows. Specific symptom progression patterns were not observed. According to our results, the virus isolate has an influence on whether symptoms develop during a GPGV infection. While yield analyses revealed that yield losses only occur in symptomatic vines and range from 13 to 96% depending on the severity of symptoms, latent infections have no impact on grape production. No relevant effects of GPGV infections on must quality were observed. Conclusions: Secondary spread of GPGV was observed in all vineyards monitored, indicating vector-borne transmission that is likely to be accelerated by human viticultural management. GPGV should be further monitored to prevent the accumulation of detrimental symptomatic isolates. The results of this study can be used to assess the risk of GPGV to viticulture and should be considered when developing management strategies against the virus. [ABSTRACT FROM AUTHOR]