Latent Infection Research Articles

Tannic acid reactivates HIV-1 latency by mediating CBX4 degradation.

HIV-1 can integrate viral DNA into host cell chromosomes and establish a long-term stable latent viral reservoir, a major obstacle in curing HIV-1 infection. The reactivation of latent proviruses with latency-reversing agents (LRAs) is a prerequisite for the eradication of viral reservoirs. Previous reports have shown that tannic acid (TA) exerts several biological functions, including antioxidant and antitumor activities. Here, we identified a novel function of TA as a reactivator of HIV-1 latency. TA showed similar features to the HIV-1 transactivator of transcription (Tat) and was able to reactivate a larger number of proviruses from various integration sites. TA also showed a strong synergistic effect with other LRAs acting on different signaling pathways. Further studies revealed that the polycomb repressive complex 1 component, chromobox protein homolog 4 (CBX4), is specifically degraded by TA through ubiquitination. CBX4 is associated with the tri-methylation at lysine 27 of histone H3 (H3K27me3) which was enriched on HIV-1 long terminal repeat regions. The TA-induced CBX4 degradation decreased the H3K27me3 enrichment and subsequently enhanced the transcriptional activity of the integrated proviruses. These results suggest that TA is an efficient LRA aiming to a new target for HIV-1 latency, which could be developed to eradicate latent proviruses.IMPORTANCEHIV-1 remains a global health challenge, with its ability to integrate into the host genome and evade the effects of drugs. To overcome this obstacle, the "shock and kill" strategy was proposed, targeting the reactivation of latent HIV-1 for subsequent eradication through antiretroviral medication and immune system reinforcement. Here, we found a new reactivator for HIV-1 latency, tannic acid (TA), which can reactivate HIV-1 latency widely and deeply. Moreover, we demonstrated that TA could promote the interaction between the polycomb repressive complex 1 component CBX4 and the E3 ubiquitin ligase cullin 4A (CUL4A), resulting in CBX4 degradation through the ubiquitin-proteasome system. These events reduce H3K27me3 enrichment in the HIV-1 long terminal repeat region, thereby promoting HIV-1 transcription and ultimately reactivating HIV-1 latent infection. Our work may facilitate the identification of new latency-reversing agents and provide more theoretical evidence for the molecular mechanism of HIV-1 latency.

Fatal Fulminant Epstein–Barr Virus (EBV) Encephalitis in Immunocompetent 5.5-Year-Old Girl—A Case Report with the Review of Diagnostic and Management Dilemmas

Introduction: Epstein–Barr virus (EBV) usually causes mild, self-limiting, or asymptomatic infection in children, typically infectious mononucleosis. The severe course is more common in immunocompromised patients. Neurological complications of primary infection, reactivation of the latent infection, or immune-mediated are well-documented. However, few published cases of fatal EBV encephalitis exist. Case presentation We report a case of a 5.5-year-old immunocompetent girl with fulminant EBV encephalitis fulfilling the criteria for the recently proposed subtype Acute Fulminant Cerebral Edema: (AFCE). The child presented with fever, vomiting, altered mental status, and ataxia. Her initial brain CT (computed tomography) scan was normal. On day 2 she developed refractory status epilepticus requiring intubation, ventilation, and sedation for airway protection and seizure control. Magnetic resonance imaging (MRI) scan showed cytotoxic brain edema. Despite intensive treatment, including acyclovir, ceftriaxone, hyperosmotic therapy (3% NaCl), intravenous immunoglobulins (IVIG), corticosteroids, as well as supportive management, on day 5 she developed signs of impending herniation. Intensification of therapy (hyperventilation, deepening sedation, mannitol) was ineffective, and a CT scan demonstrated generalized brain edema with tonsillar herniation. EBV primary infection was confirmed by serology and qPCR in blood samples and post-mortem brain tissue. An autopsy was consistent with the early phase of viral encephalitis. Conclusions This case confirms that normal or non-specific CT and MRI scans do not exclude encephalitis diagnosis if clinical presentation fulfills the diagnostic criteria. The implementation of prophylactic anticonvulsants could improve outcomes. Intracranial pressure (ICP) monitoring should be considered in AFCE for better ICP management. Decompressive craniectomy might be a life-saving option in refractory cases. An encephalitis management algorithm is proposed.

Third intracellular loop of HCMV US28 is necessary for signaling and viral reactivation.

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

A KSHV RNA-binding protein promotes FOS to inhibit nuclease AEN and transactivate RGS2 for AKT phosphorylation.

Kaposi's sarcoma-associated herpesvirus (KSHV) encodes an RNA-binding protein ORF57 in lytic infection. Using an optimized CLIP-seq in this report, we identified ORF57-bound transcripts from 544 host protein-coding genes. By comparing with the RNA-seq profiles from BCBL-1 cells with latent and lytic KSHV infection and from HEK293T cells with and without ORF57 expression, we identified FOS RNA as one of the major ORF57-specific RNA targets. FOS dimerizes with JUN as a transcription factor AP-1 involved in cell proliferation, differentiation, and transformation. Knockout of the ORF57 gene from the KSHV genome led BAC16-iSLK cells incapable of FOS expression in KSHV lytic infection. The dysfunctional KSHV genome in FOS expression could be rescued by Lenti-ORF57 virus infection. ORF57 protein does not regulate FOS translation but binds to the 13-nt RNA motif near the FOS RNA 5' end and prolongs FOS mRNA half-life 7.7 times longer than it is in the absence of ORF57. This binding of ORF57 to FOS RNA is likely competitive to the binding of host nuclease AEN (ISG20L1) of which physiological RNase activity remains unknown. KSHV infection inhibits the expression of AEN, but not exosomal RNA helicase MTR4. FOS expression mediated by ORF57 inhibits AEN transcription through FOS binding to AEN promoter but transactivates RGS2, a regulator of G-protein-coupled receptors. FOS binds a conserved AP-1 site in the RGS2 promoter and enhances RGS2 expression to phosphorylate AKT. Altogether, we have discovered that KSHV ORF57 specifically binds and stabilizes FOS RNA to increase FOS expression, thereby disturbing host gene expression and inducing pathogenesis during KSHV lytic infection.IMPORTANCEWe discovered that FOS, a heterodimer component of oncogenic transcription factor AP-1, is highly elevated in KSHV-infected cells by expression of a viral lytic RNA-binding protein, ORF57, which binds a 13-nt RNA motif near the FOS RNA 5' end to prolong FOS RNA half-life. This binding of ORF57 to FOS RNA is competitive to the binding of host RNA destabilizer(s). KSHV infection inhibits expression of host nuclease AEN, but not MTR4. FOS inhibits AEN transcription by binding to the AEN promoter but transactivates RGS2 by binding to a conserved AP-1 site in the RGS2 promoter, thereby enhancing RGS2 expression and phosphorylation of AKT. Thus, KSHV lytic infection controls the expression of a subset of genes for signaling, cell cycle progression, and proliferation to potentially contribute to viral oncogenesis.

The gE/gI complex is necessary for kinesin-1 recruitment during alphaherpesvirus egress from neurons.

Alphaherpesviruses include important human and veterinary pathogens that share a unique propensity to establish life-long latent infections in the peripheral nervous system. Upon reactivation, these viruses navigate back to body surfaces and transmit to new hosts. In this study, we demonstrate that the virus gE/gI-US9p membrane complex routes virus particles down this complex neuronal egress pathway by coordinating their association with multiple kinesin microtubule motors.

The quality of SIV-specific fCD8 T cells limits SIV RNA production in Tfh cells during antiretroviral therapy.

The attack and defense of infected cells and cytotoxic CD8 T cells occur in germinal centers in lymphoid tissue in chronic persistent HIV/SIV infection. Latently infected cells, the therapeutic target of HIV infection, accumulate in follicular helper T (Tfh) cells in lymphoid tissue; the impact of HIV-specific follicular CD8 (fCD8) T cells in lymphoid tissue on the latently infected cells remains unknown. We infected 15 cynomolgus macaques with SIVmac239 and examined the contribution of SIV-Gag-specific fCD8 T cells, defined by activation-induced markers (AIMs), to SIV-infected cells. Eight out of the 15 infected macaques served as progressors; a chronic phase combination antiretroviral therapy (cART) model was established for the eight macaques (progressors) with chronic persistent infection status, wherein cART was started in the chronic phase and discontinued after 27 weeks. Seven macaques that naturally controlled the viremia served as natural controllers. The frequency of SIV-Gag-specific fCD8 T cells was inversely correlated with the amount of cell-associated SIV-gag RNA in the Tfh only under cART or in the controllers but not in untreated progressors. scRNA-seq of SIV-Gag-specific fCD8 T cells in various conditions revealed that the gene expression pattern of SIV-Gag-specific fCD8 T cells in the controllers was closer to that of those under cART than the untreated progressors. Comparing the SIV-Gag-specific fCD8 T cells of those under cART to the controllers revealed their more exhausted and immunosenescent nature under cART. Improving the HIV/SIV-specific fCD8 T cells under cART by targeting those pathways might contribute to the development of potential curative strategies.IMPORTANCEWe infected cynomolgus macaques with SIVmac239 to establish an SIV-chronically infected cART model. We performed an in-depth characterization of Tfh and fCD8 T cells in three conditions-chronic stage of untreated, cART-treated, and natural controller cynomolgus macaques-by combining tissue section analysis and single-cell analyses of sorted cells. We revealed the inverse relationship between Tfh infection and SIV-Gag-specific fCD8 T cell frequencies as observed in HIV-infected individuals, thereby establishing the cynomolgus macaque as a relevant animal model to study the determinants of HIV/SIV persistence in lymphoid tissue. Additionally, scRNA-seq analysis of SIV-Gag-specific fCD8 T cells revealed an enrichment of exhausted or senescent transcriptomic signatures under cART. These data will provide the basic insights into virus-host CD8 T cell interactions, particularly within the follicular region, during latent HIV infection under ART.

Evasion of the Antiviral Innate Immunity by PRV

Pseudorabies virus (PRV) establishes persistent latent infections by effectively evading the host’s antiviral innate immune response. PRV has developed sophisticated strategies to bypass immune surveillance through coevolution with its host. Currently, no effective vaccine exists to prevent or treat infections caused by emerging PRV variants, and the interactions between PRV and the host’s innate immune defenses remain incompletely understood. Nevertheless, ongoing research is uncovering insights that may lead to novel treatments and preventive approaches for herpesvirus-related diseases. This review summarizes recent advances in understanding how PRV disrupts key adaptors in immune signaling pathways to evade antiviral immunity. Additionally, we explored the intrinsic cellular defenses that play crucial roles in combating viral invasion. A deeper understanding of the immune evasion strategies of PRV could inform the development of new therapeutic targets and vaccines.

Calcifediol and paricalcitol as adjunctive therapies for HSV-1 keratitis and corneal perforation: A case report.

Herpes simplex virus 1 establishes a latent infection in trigeminal ganglia. Reactivation causes cold sores, as well as viral keratitis. The purpose of this study was to report potential benefits of using active vitamin D receptor ligands (VDR-agonists) as adjunctive therapies for the treatment of infectious corneal perforations, and prevention of HSV recurrence. A 57-year-old female with a past history of episodic, poorly-healing, corneal erosions, recurring orolabial herpetic lesions, as well as PCR-confirmed recurrences of herpes simplex keratitis presented with a burning sensation and slight pain in the right eye. Examination indicated HSV keratitis. Topical antibiotic and oral antiviral treatments were prescribed. Despite these standard-of-care treatments, a perforated corneal ulcer ensued. Corneal perforation associated with HSV-1 keratitis recurrence, later confirmed by PCR analysis of corneal scrapings. Corneal perforation was treated with a human fibrin glue, fortified with multilayered amniotic membrane transplant, as well as a therapeutical contact lens. Following surgery, calcifediol and paricalcitol were started as oral adjunctive therapies in an attempt to boost tissue regeneration and innate-immunity within the slow-healing cornea. Anterior segment optical-coherence tomography was used to measure corneal thickness. Frequent follow-ups with various specialists allowed for comprehensive patient evaluation, and meticulous screening for any signs indicating potential HSV-1 recurrence. Following calcifediol-paricalcitol therapy corneal thickening, and re-epithelization ensued. During combined calcifediol-paricalcitol therapy, the patient has had no recurrence of herpes simplex keratitis, or orolabial herpes lesions. Corneal stabilization avoided a high-risk, full-thickness corneal transplantation, facilitating future cataract surgery, and allowing for some degree of visual recovery in this eye.

Variation in HIV-1 Tat activity is a key determinant in the establishment of latent infection.

Despite effective treatment, Human immunodeficiency virus (HIV) persists in optimally treated people as a transcriptionally silent provirus. Latently infected cells evade the immune system and the harmful effects of the virus, thereby creating a long-lasting reservoir of HIV. To gain a deeper insight into the molecular mechanisms of HIV latency establishment, we constructed a series of HIV-1 fluorescent reporter viruses that distinguish active versus latent infection. We unexpectedly observed that the proportion of active-to-latent infection depended on a limiting viral factor, which created a bottle neck that could be overcome by superinfection of the cell, T cell activation or overexpression of HIV-1 trans activator of transcription (Tat). In addition, we found that tat and rev expression levels vary amongst HIV molecular clones and that tat levels were an important variable in latency establishment. Lower rev levels limited viral protein expression whereas lower Tat levels or mutation of the Tat binding element promoted latent infection that was resistant to reactivation even in fully activated primary T cells. Nevertheless, we found that combinations of latency reversal agents targeting both cellular activation and histone acetylation pathways overcame deficiencies in the Tat-TAR axis of transcription regulation. These results provide additional insight into the mechanisms of latency establishment and inform Tat-centered approaches to cure HIV.

Identifying the key regulators orchestrating Epstein-Barr virus reactivation

Epstein-Barr virus (EBV) infects more than 90% of the human population worldwide and establishes lifelong infection in hosts by switching between latent and lytic infection. EBV latency can be reactivated under appropriate conditions, leading to expression of the viral lytic genes and production of infectious progeny viruses. EBV reactivation involves crosstalk between various factors and signaling pathways, and the subsequent complicated virus-host interplays determine whether EBV continues to propagate. However, the detailed mechanisms underlying these processes remain unclear. In this review, we summarize the critical factors regulating EBV reactivation and the associated mechanisms. This encompasses the transcription and post-transcriptional regulation of immediate-early (IE) genes, the functions of viral factors on viral DNA replication and progeny virus production, the mechanisms through which viral proteins disrupt and inhibit the host’s innate immune response, and the host factors that modulate EBV reactivation. Finally, we explore the potential applications of novel technologies in studying EBV reactivation, providing novel insights into the investigation of mechanisms governing EBV reactivation and the development of anti-EBV therapeutic strategies.

Mycobacterium tuberculosis F-ATP Synthase Inhibitors and Targets

Mycobacteria tuberculosis (Mtb) infection causes tuberculosis (TB). TB is one of the most intractable infectious diseases, causing over 1.13 million deaths annually. Under harsh growing conditions, the innate response of mycobacteria is to shut down its respiratory metabolism to a basal level, transit into a dormant, non-replicating phase to preserve viability, and establish latent infection. Mtb utilizes non-canonical regulatory mechanisms, such as alternative oxidase pathways, to survive in low oxygen/nutrient conditions. The bacterium’s survival in its native microenvironmental niches is aided by its ability to evolve mutations to drug binding sites, enhance overexpression of various enzymes that activate β-lactam antibiotics hydrolysis, or stimulate efflux pathways to ward off the effect of antibiotics. Bedaquiline and its 3,5-dialkoxypyridine analogs, sudapyridine and squaramide S31f, have been shown to be potent Mtb F1FO-ATP synthase inhibitors of replicating and non-replicating Mtb and have brought oxidative phosphorylation into focus as an anti-TB target. In this review, we attempt to highlight non-canonical structural and regulatory pathogen-specific epitopes of the F1-domain, ligand development on such sites, structural classes of inhibitors targeting the Fo-domain, and alternative respiratory metabolic responses that Mtb employs in response to bedaquiline to ensure its survival and establish latent infection.

Human immunodeficiency virus-1 induces host genomic R-loops and preferentially integrates its genome near the R-loop regions

Although HIV-1 integration sites favor active transcription units in the human genome, high-resolution analysis of individual HIV-1 integration sites has shown that the virus can integrate into a variety of host genomic locations, including non-genic regions. The invisible infection by HIV-1 integrating into non-genic regions, challenging the traditional understanding of HIV-1 integration site selection, is more problematic because they are selected for preservation in the host genome during prolonged antiretroviral therapies. Here, we showed that HIV-1 integrates its viral genome into the vicinity of R-loops, a genomic structure composed of DNA-RNA hybrids. VSV-G-pseudotyped HIV-1 infection initiates the formation of R-loops in both genic and non-genic regions of the host genome and preferentially integrates into R-loop-rich regions. Using a HeLa cell model that can independently control transcriptional activity and R-loop formation, we demonstrated that the exogenous formation of R-loops directs HIV-1 integration-targeting sites. We also found that HIV-1 integrase proteins physically bind to the host genomic R-loops. These findings provide novel insights into the mechanisms underlying retroviral integration and the new strategies for antiretroviral therapy against HIV-1 latent infection.

Differential distribution of NAT2 polymorphisms and NAT2 acetylator phenotypes among indigenous populations of the Brazilian Amazon.

We report, for the first time, the distribution of four no-function NAT2 single nucleotide polymorphisms and inferred NAT2 acetylator phenotypes in three indigenous groups (Munduruku, Paiter-Suruí, and Yanomami), living in reservation areas in the Brazilian Amazon. Two hundred and seventy-six participants from three indigenous groups (92 for each group) were included and genotyped for four NAT2 polymorphisms (rs1801279, rs1801280, rs1799930, and rs1799931) by the TaqMan system. Minor Allele Frequency (MAF) was determined and NAT2 acetylator phenotypes were inferred. NAT2 rs1801279G>A was absent in all cohorts; rs1799930G>A was absent in Yanomami and rare (MAF 0.016) in Munduruku and Paiter-Suruí; MAF of rs1801280T>C ranged five-fold (0.092-0.433), and MAF of rs1799931G>A varied between 0.179 and 0.283, among the three groups. The distribution of NAT2 phenotypes differed significantly across cohorts; the prevalence of the slow acetylator phenotype ranged from 16.3% in Yanomami to 33.3% in Munduruku to 48.9% in Paiter-Suruí. This three-fold range of variation is of major clinical relevance because the NAT2 slow phenotype is associated with higher risk of hepatotoxicity with antituberculosis chemotherapy and high incidence rates of tuberculosis and burden of latent infection among Munduruku, Paiter-Surui, and Yanomami peoples. According to the frequency of the NAT2 slow acetylator phenotype, the estimated number of individuals needed to be genotyped to prevent one additional event of hepatotoxicity range from 31 (Munduruku) to 39 (Paiter-Surui) and to 67 (Yanomami). The rs1801279 polymorphism was not found in any of the cohorts, while the MAF of the other polymorphisms showed significant variation between the cohorts. The difference in the prevalence of the NAT2 slow acetylator phenotype, which is linked to isoniazid-induced hepatotoxicity, was observed in the different study cohorts.

An Assessment of KAP Towards LTBI in Under-5 Children among Physicians Treating Adult/Adolescent TB Patients in Dhaka City

<i>Introduction:</i> LTBI is the precursor to TB, making early detection and treatment of infected children vital to preventing pediatric morbidity and mortality. This study assesses the knowledge, attitudes, and practices of physicians treating adult and adolescent TB patients in managing LTBI among under-5 children in Dhaka. <i>Aim of the study:</i> The aim of the study was to evaluate the knowledge, attitude, and practices of physicians treating adult and adolescent tuberculosis patients in Dhaka City regarding the diagnosis and management of latent tuberculosis infection (LTBI) in under-5 children. <i>Methods: </i>This six-month cross-sectional, semi-qualitative study was conducted from January to June 2020 at the Department of Paediatrics in five Dhaka hospitals, involving 50 physicians treating adult and adolescent TB patients. Data were collected through standardized questionnaires, with consent obtained, and qualitative responses categorized and scored using SPSS Version 25.0. <i>Result: </i>Among 50 physicians, most were aged 30-39, and 62% had recent TB training. Knowledge of latent tuberculosis infection (LTBI) was limited, with only 14% accurately defining it, while 88% acknowledged isoniazid preventive therapy (IPT) availability. Only 12% inquired about family members of pulmonary TB patients, and 10% asked about under-five children. A significant 80% had no involvement in managing LTBI in children, with just 6% prescribing IPT. Additionally, 84% believed IPT could cause drug resistance, and those with recent training scored higher in knowledge. <i>Conclusion: </i>This KAP study identifies key barriers to LTBI tracing and IPT/TPT implementation in children under five, emphasizing the need for structured training to enhance physician practices.

Detection of HHV-5 HHV-6a HHV-6b and HHV-7 in the urine: potential use as a non-invasive diagnostic tool for immune profiling

Decline in immune function with age has been studied extensively, but approaches to immune restoration have been hampered by the lack of simple methods of identifying individuals whose immune system is in decline. Our approach has been to identify individuals whose immune decline has led to a loss of control of common latent viral infections and their consequent reactivation. Viruses excreted in urine were detected and quantified and we believe this approach could provide a 'surrogate marker' for identifying immune compromised individuals. Here we report the detection of human herpes virus (HHV) 5, 6a, 6b and 7 in the urine of healthy individuals over a wide age range and their correlation with T cell receptor excision circle (TREC) data. The results did not show a clear correlation between TREC values and the detection of individual specific viruses or viral load values when measured singly. However, a correlation was found between low TREC values and the detection of several different human herpes viruses in the urine in males. We present evidence suggesting that for males, the detection of three or more different human herpes viruses in the urine could identify individuals with declining immune function as evidenced by their significantly lower TREC levels.

Transcriptome analysis reveals that PRV XJ delgE/gI/TK protects against intestinal damage in nose-dropping-infected mice by regulating ECM-ITGA/ITGB-P-FAK.

Pseudorabies virus (PRV) is an ideal model for mechanistic investigations into α-herpesvirus. The neurotropism and latent infection of PRV have been extensively studied. Apart from neurological symptoms, diarrhea caused by PRV infection is also an essential cause of mortality in newborn and weaned piglets. However, little research has been done on PRV invasion of the gut. To fill this gap, a nasal drip PRV-infection mouse model was developed, consisting of three groups: the challenged group (Group A), the immunization-challenged group (Group B), and a mock group (Group C). The results showed that immunization with PRV XJ delgE/gI/TK successfully prevented intestinal damage caused by PRV drop-nose infection. Subsequently, intestines were collected for transcriptional analysis. Differentially expressed genes analysis revealed that PRV XJ delgE/gI/TK was effective in reducing the organismal intestinal transcriptional activity caused by PRV. The Group A vs Group C and Group A vs Group B had similar Kyoto Encyclopedia of Genes and Genomes (KEGG)-enriched signaling pathways and the differentially expressed genes were primarily enriched in pathways, such as cell adhesion molecules, focal adhesion kinase, and actin cytoskeleton regulation. Notably, transcriptome analysis indicated that genes associated with the focal adhesion kinase (FAK) signaling pathway (ECM-ITGA/ITGB-p-FAK) were significantly more highly expressed in Group A than in Group B and Group C. The results of quantitative real-time PCR (RT-qPCR) and western blotting were consistent with KEGG analysis. Therefore, we hypothesized that PRV promotes self-infection through activation of the ECM-ITGA/ITGB-p-FAK signaling pathway and that PRV XJ delgE/gI/TK immunization could attenuate the intestinal damage caused by PRV by inhibiting the activation of this pathway.IMPORTANCEPseudorabies virus (PRV) poses a significant threat to the swine industry and public health due to its ability to infect multiple species, including humans, leading to substantial economic losses and potential health risks. This study addresses a critical gap in understanding the impact of PRV infection on the gut, which has been less explored compared to its neurological effects. By developing a drip-nose PRV-infection mouse model, the research indicated that PRV might promote self-infection through activation of the ECM-ITGA/ITGB-p-FAK signaling pathway, and PRV XJ delgE/gI/TK immunization effectively prevents intestinal damage by significantly reducing the expression of genes in the ECM-ITGA/ITGB-p-FAK signaling pathway. The research has important implications for the swine industry and public health by contributing to the development of better vaccines and treatments, ultimately helping to control PRV and prevent its cross-species transmission.

Mathematical modeling of age-specific intervention strategies for latent tuberculosis infection

Tuberculosis (TB) remains a leading cause of death from a single infectious agent, with TB deaths in 2021 surpassing those from HIV/AIDS. In alignment with the WHO’s End TB strategy, South Korea launched a TB elimination plan in 2006. Recognizing the significance of age-dependent factors, we developed a comprehensive mathematical model to analyze the age-specific transmission dynamics of TB, including latent tuberculosis infection (LTBI), from 2012 to 2021. Our previous research focused on age-specific TB dynamics and the effects of various interventions on reducing active TB cases within different age groups. In this study, we enhance our model to include both short and long latent TB cases, allowing for a more detailed investigation of age-specific LTBI interventions and their impact on TB reduction. Utilizing the Markov Chain Monte Carlo (MCMC) method within a Bayesian inferential framework, we estimated model parameters that closely align with actual data with high accuracy. Our results revealed that non-elderly individuals are more responsive to transmission rates, whereas elderly individuals are more influenced by LTBI treatment. Strengthening LTBI treatment interventions significantly reduce TB infectious cases, particularly among those aged 65 and older. Detection and treatment strategies specifically targeting LTBI in the elderly population, along with primary TB treatments, are essential for TB control. The Korean government aims to reduce the TB incidence rate to below 20 cases per 100,000 by 2027. Our results indicate that this goal can be achieved by enhancing LTBI detection rates and treatment compliance levels. Specifically, our findings suggest that improving LTBI treatment interventions could lower the TB incidence to 10 cases per 100,000 by 2030. This underscores the critical importance of implementing age-specific LTBI detection and treatment interventions to effectively decrease TB incidence in South Korea.

Reproductive effects of wartime stress and possibilities of their correction (Literature review)

The article presents modern literary data and data of own clinical observations regarding the effects of long-term chronic stress on reproductive processes with an emphasis on the effects of wartime. All stages of the reproductive cycle, from the regulation of the menstrual cycle, conception and implantation to the birth of a child, are energy-consuming and unprofitable for the body. All these processes require a lot of energy, but their purpose is to reproduce the species, not to maintain homeostasis. Therefore, the body temporarily slows down these processes, withdraws energy aimed at their support, and uses it to resist stress.The biological meaning of inhibition of reproductive function in stressful conditions is that if a woman becomes pregnant under unfavorable conditions, it is bad for her body, and for the offspring, and for the future prospects of the biological species as a whole. Therefore, from an evolutionary point of view, it is very beneficial to reduce the production of hormones, exclude ovulation and prevent implantation, and reduce libido during periods of high stress.Stress causes activation of the neuroendocrine and sympatho-adrenal systems, which leads to the release of such hormones as cortisol, adrenaline, norepinephrine into the blood. This helps to mobilize the body’s resources to overcome a threatening situation. However, prolonged stress depletes these systems and leads to maladjustment and increased risk of disease. Stress hormones affect all body systems, including the reproductive system. According to the literature, stress disorders occur three times more often in women than in men.In conditions of chronic stress, in particular during war, pregnancy complications can be caused by stress of various origins: metabolic, associated with micronutrient deficiency, psychological, physical, a combination of factors.Prenatal stress during wartime is a part of our existence, which reduces the quality of life of a pregnant woman and affects the intrauterine development of the fetus and the subsequent health of the child. Long-term chronic stress also leads to deterioration of the general state of health of the expectant mother: it reduces work capacity and appetite, causes lethargy, apathy, sleep disturbances, and increases the risk of obstetric complications.Stress negatively affects the state of immunity of the female population both before conception and during pregnancy, which can lead to the activation of latent infections, and makes the body of pregnant women more vulnerable to acute seasonal infections. This is also facilitated by the lack of necessary vitamins and trace elements with antioxidant properties in conditions of occupation, disruptions in the supply of medicines to certain problematic regions of the country, frequent changes of residence, etc.During pregnancy, all the negative effects of wartime can be realized in the form of major obstetric syndromes. In conditions of pronounced energy deficit caused by long-term stress, the body has to provide for itself to the detriment of the future child, which leads to ZRP, and in the most tragic cases – to intrauterine death. Violation of the psycho-emotional state of pregnant women today leads to the birth of “children of war” – insecure, low self-esteem, deeply ill babies with mental disorders.For the onset of pregnancy and its successful bearing, vitamins and micro/macroelements with antioxidant properties are needed in order to resist oxidant stress inherent in stressful conditions (vitamins of group B, vitamin D, iron, magnesium, omega-3 polyunsaturated fatty acids, L-arginine, L- carnitine). Rational management of pregnancy in today’s complex conditions should be complex and multi-vector. One of the promising directions in ensuring an uncomplicated course of pregnancy and successful perinatal outcomes is work with perinatal psychologists. At the same time, the use of additional psychosomatic effects of basic therapy should not be underestimated.

Comment on 'How useful is chest X-ray in addition to routine QuantiFERON® in the detection of latent tuberculosis prior to biologics?'

This study reviewed 200 dermatology patients in Ireland on biologics, assessing the value of chest X-rays (CXRs) in addition to QuantiFERON/Interferon-gamma-releasing assay (IGRA) for detecting latent tuberculosis infection (LTBI). The majority (97.5%) had negative IGRA results, with only two showing TB-like findings on CXR. No patients with positive IGRA had CXR signs of TB, and none began LTBI treatment based solely on CXR findings. Echoing Kearney et al.'s results, the study supports using IGRA alone for LTBI screening in low-risk patients, suggesting that routine CXR may be unnecessary and advocating for updated guidelines to reflect this.

Abstract A035: Infection of primary mammary fibroblasts with cytomegalovirus coordinately increases autotaxin-lysophosphatidate-inflammatory signaling, which could increase breast cancer metastasis

Abstract Background: Metastatic breast cancer is the most prevalent cause of mortality by cancer-related deaths in women. Our group showed that the 63% of Canadian breast cancer patients who were infected with CMV were 5.6-times more likely to develop Stage IV cancers with reduced relapse-free survival. Also, the metastatic phenotype of breast tumors and the number and sizes of lung metastases were increased in mice with latent infections. Fibroblasts are important sites of CMV infection. Cancer-associated fibroblasts (CAFs) are also major sites of autotaxin (ATX) secretion in breast tumors, whereas ATX production and CMV infection in breast cancer cells is negligible. ATX produces lysophosphatidate (LPA), which increases inflammatory cytokine production that stimulates further ATX secretion in a feedforward cycle. LPA promotes breast tumor growth and metastasis by signaling through six G protein-coupled receptors. Signaling is terminated by lipid phosphate phosphatases (LPPs)-1 and -3, which degrade LPA and are decreased in breast tumors. Hypothesis: Breast cancer metastasis could be increased by active CMV infection of CAFs through increased inflammation and LPA signaling. Results: Quiescent fibroblasts isolated and cultured from mammary tissue of non-tumor bearing mice (n>3) produced negligible quantities of ATX. LPA signaling was coordinately promoted in these primary fibroblasts infected for 48 h with 1 MOI of mouse CMV (n=3) with a 5-fold increase in mRNA for ATX (p=0.008), increased mRNAs for LPA2,3,4 receptors (p<0.05) and decreased mRNA expressions for LPP1 and LPP3 (p<0.05). An increase in the secretion of granulocyte monocyte-colony stimulating factor of 548 pg/ml (p=0.01) and Interleukin-6 by 8307 pg/ml (p=0.03) was observed post infection (n=5), thus creating a pro-inflammatory environment. Increased mRNA expression of fibroblast markers, including alpha-smooth muscle actin (p=0.005), fibroblast-associated protein (p=0.007), epidermal growth factor receptor (EGFR) (p=0.001) and transforming growth factor- ß receptor 1 (TGF-ßR1) (p=0.03) was also observed post-infection (n=3). The results were analyzed by student’s t-test. Assessment of these factors in breast cancer patients (n=1100) using the Tumor Immune Estimation Resource Analysis showed a positive correlation in the expression of EGFR and TGF-ßR1 with the LPA3,4 receptors (p<0.05). Conclusion: The changes in expression of ATX, LPA receptors and LPPs in CMV- infected fibroblasts are consistent with increased metastasis. Our results show that mCMV infection of primary mammary fibroblasts dramatically reprograms them to express CAF-like properties and promotes ATX-LPA-inflammatory signaling. CAFs are a major constituent of the tumor stroma. They promote tumor progression by secreting factors such as ATX, which increases metastasis, fibrosis and favors immunosuppression. Our results support the use of pharmacological agents to block signaling by the ATX-LPA-inflammatory cycle to treat breast and other cancers, especially for the majority of patients who are infected with CMV. Citation Format: Humayara Khan, Xiaoyun Tang, Frank Wuest, David N. Brindley, Denise G. Hemmings. Infection of primary mammary fibroblasts with cytomegalovirus coordinately increases autotaxin-lysophosphatidate-inflammatory signaling, which could increase breast cancer metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A035.