The Small GTPase Ran Increases Sensitivity of Ovarian Cancer Cells to Oncolytic Vesicular Stomatitis Virus

Background/Objectives: Ovarian cancer is the deadliest gynecologic cancer, and with the majority of patients dying within the first five years of diagnosis, new therapeutic options are required. The small guanosine triphosphatase (GTPase) Ras-related nuclear protein (Ran) has been reported to be highly expressed in high-grade serous ovarian cancers (HGSOCs) and associated with poor outcomes. Blocking Ran function or preventing its expression were shown to be promising treatment strategies, however, there are currently no small molecule inhibitors available to specifically inhibit Ran function. Interestingly, a previous study suggested that the Vesicular stomatitis virus (VSV) could inhibit Ran activity. Given that VSV is an oncolytic virus (OV) and, therefore, has anti-cancer activity, we reasoned that oncolytic VSV (oVSV) might be particularly effective against ovarian cancer via Ran inhibition. Methods: We evaluated the sensitivity of patient-derived ovarian cancer cell lines to oVSV, as well as the impact of oVSV on Ran and vice versa, using overexpression systems, small interfering RNAs (siRNAs), and drug inhibition. Results: In this study, we evaluated the interplay between oVSV and Ran and found that, although oVSV does not consistently block Ran, increased Ran activation allows for better oVSV replication and tumor cell killing. Conclusions: Our study reveals a positive impact of Ran on oVSV sensitivity. Given the high expression of Ran in HGSOCs, which are particularly aggressive ovarian cancers, our data suggest that oVSV could be effective against the deadliest form of the disease.

Endoscopic innovations in diagnosis and management of pancreatic cancer: a narrative review and future directions

Pancreatic cancer serves as the third leading cause of cancer-associated morbidity and mortality in the United States, with a 5-year survival rate of only 12% with an expected increase in incidence and mortality in the coming years. Pancreatic ductal adenocarcinomas constitute most pancreatic malignancies. Certain genetic syndromes, including Lynch syndrome, hereditary breast and ovarian cancer syndrome, hereditary pancreatitis, familial adenomatous polyposis, Peutz-Jeghers syndrome, familial pancreatic cancer mutation, and ataxia telangiectasia, confer a significantly higher risk. Screening for pancreatic malignancies currently targets patients with germline mutations or those with significant family history. Screening the general population is not currently viable owing to overall low incidence and lack of specific tests. Endoscopic ultrasound (EUS) and its applied advances are increasingly being used for surveillance, diagnosis, and management of pancreatic malignancies and have now become an indispensable tool in their management. For patients with risk factors, EUS in combination with magnetic resonance imaging/magnetic resonance cholangiopancreatography is used for screening. The role of endoscopic modalities has been expanding with the increased utilization of endoscopic retrograde cholangiopancreatography, EUS-directed therapies include EUS-guided fine-needle aspiration and EUS-fine-needle biopsy (FNB). EUS combined with FNB has the highest specificity and sensitivity for detecting pancreatic cancer amongst available modalities. Studies also recognize that artificial intelligence assisted EUS in the early detection of pancreatic cancer. At the same time, surgical resection has been historically considered the only curative treatment for pancreatic cancer, over 80% of patients present with unresectable disease. We also discuss EUS-guided therapies of physicochemicals (radiofrequency ablation, brachytherapy, and intratumor chemotherapy), biological agents (gene therapies and oncolytic viruses), and immunotherapy. We aim to perform a detailed review of the current burden, risk factors, role of screening, diagnosis, and endoscopic advances in the treatment modalities available for pancreatic cancer.

The Role of Inflammation in the Pathogenesis of Viral Respiratory Infections

Viral respiratory infections (VRIs) are a leading cause of morbidity and mortality worldwide, making them a significant public health concern. During infection, respiratory viruses, including Influenza virus, SARS-CoV-2, and respiratory syncytial virus (RSV), trigger an antiviral immune response, specifically boosting the inflammatory response that plays a critical role in their pathogenesis. The inflammatory response induced by respiratory viruses can be a double-edged sword since it can be initially induced to be antiviral and protective/reparative from virus-induced injuries. Still, it can also be detrimental to host cells and tissues. However, the mechanisms that differentiate the complex crosstalk between favorable host inflammatory responses and harmful inflammatory responses are poorly understood. This review explores the complex interplay between viral pathogens and the host immune response, mainly focusing on the role of inflammation in the pathogenesis of VRIs. We discuss how inflammation can both contain and exacerbate the progression of viral infections, highlighting potential therapeutic targets and emerging drugs for modulating the aberrant inflammatory responses during VRIs.

Pre-autism: Advancing early identification and intervention in autism

Autism spectrum disorder (ASD) is often diagnosed long after symptoms have become noticeable. This delay can make it difficult to provide early intervention, which can impact long-term outcomes. The concept of "pre-autism" highlights the phase before a formal diagnosis of ASD, providing an opportunity for earlier identification and intervention, which could be a turning point in ASD management. In a previous article, we explored different ways of diagnosing pre-autism, including historical records, physical markers, laboratory tests, and radiological evidence. This manuscript builds on that foundation by emphasizing the importance of early diagnosis and intervention in ASD. Recent research advancements have clarified that ASD presentations can be complex, and individualized support strategies are necessary. The significance of pre-autism lies in its potential to alter the trajectory of ASD through early detection and intervention despite challenges such as limited awareness and variability in symptom presentation. Biomarkers and diagnostic tools have shown promise as avenues for early detection, but it is essential to exercise caution and not rely too heavily on yet-to-be-established markers. Addressing these challenges requires a collaborative effort to increase awareness, improve access to diagnostic tools, and foster inclusive environments. Ultimately, this manuscript calls for ongoing research, advocacy, and resource allocation to enhance early detection and intervention efforts, ensuring optimal outcomes for individuals on the autism spectrum.

E2 Ubiquitin-Conjugating Enzymes Regulates Dengue Virus-2 Replication in Aedes albopictus

Aedes albopictus, a major vector of dengue virus (DENV), has a global distribution. Identifying the key components of the ubiquitin system of A. albopictus essential for the replication of viruses could help identify targets for developing broad-spectrum antiviral strategies. This study explores the interaction between E2 ubiquitin-conjugating enzymes (Ubc9) and DENV-2 proteins (NS1, NS5, and E) using cell culture and mosquito models. The replication of DENV-2 and the knockdown efficiency of the Ubc9 gene were assessed through reverse transcription-quantitative polymerase chain reaction. The DENV-2-related protein expression was evaluated via Western blot analysis. The interaction between Ubc9 and DENV E and NS5 proteins was investigated through confocal immunofluorescence and co-immunoprecipitation. RNA interference technology was employed to silence Ubc9 expression in C6/36 cells and in A. albopictus mosquitoes. The expression level of Ubc9 in the DENV-2-infected group was 3.5-fold higher than that in the control group. The Ubc9 gene expression in the midgut tissue of the mosquito was significantly upregulated. Transfection of C6/36 and BHK-21 cells with the pAc5.1b-EGFP-Ubc9-HA vector led to the overexpression of Ubc9, which decreased the transcription levels of DENV E and NS1, NS5 proteins. The difference was statistically significant (F = 24.27, p < 0.01). The expression levels of DENV NS5 and E proteins significantly decreased after infection with DENV-2, suggesting that the depletion of Ubc9 may limit the replication of DENV-2. Ubc9 regulates DENV-2 replication through SUMOylation in the cells and A. albopictus, potentially affecting vector competence and DENV transmission. This is the first study to demonstrate that the Ubc9 of A. albopictus plays a significant role in regulating the replication of DENV in both mosquito cells and the mosquito itself. The study results may prove useful in designing appropriate therapeutic approaches for dengue and associated complications.

Case report: Malaria and hepatitis E coinfection-first experience with such imported entity in Serbia

Acute hepatitis E virus (HEV) and malaria are not rare infections in tropical countries; however, in the European continent, such imported entity has not been reported up to now. Herein, we report a 24-year-old male suffering from malaria and hepatitis E, who was admitted with acute hepatic failure dark colored urine, followed by coagulation and inflammation parameters increase. Blood smear analysis revealed the presence of Plasmodium falciparum, while serological tests revealed anti-HEV IgM antibodies. After the recommended antimalarial drugs and supportive therapy, the patient survived and was discharged disease-free. Conclusions: Following WHO guidelines for the treatment of severe malaria, full recovery in patient was achieved.

Bioinformatic Resources for Exploring Human-virus Protein-protein Interactions Based on Binding Modes

Historically, there have been many outbreaks of viral diseases that have continued to claim millions of lives. Research on human-virus protein-protein interactions (PPIs) is vital to understanding the principles of human-virus relationships, providing an essential foundation for developing virus control strategies to combat diseases. The rapidly accumulating data on human-virus PPIs offer unprecedented opportunities for bioinformatics research around human-virus PPIs. However, available detailed analyses and summaries to help use these resources systematically and efficiently are lacking. Here, we comprehensively review the bioinformatic resources used in human-virus PPI research, and discuss and compare their functions, performance, and limitations. This review aims to provide researchers with a bioinformatic toolbox that will hopefully better facilitate the exploration of human-virus PPIs based on binding modes.

FGF receptor kinase inhibitors exhibit broad antiviral activity by targeting Src family kinases

The development of antiviral strategies is a key task of biomedical research, but broad-spectrum virus inhibitors are scarce. Here we show that fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors reduce infection of several cell types with DNA and RNA viruses by blocking early stages of infection, but not viral cell association. Unexpectedly, their antiviral activity was largely independent of FGFR kinase inhibition. RNA profiling showed upregulation of interferon response genes by FGFR inhibitors, but their expression did not correlate with the antiviral activity in infected cells. Using bioinformatics analysis of kinome data, targeted kinase assays, siRNA-mediated knock-down and pharmacological inhibition experiments, we show that blockade of Src family kinases, in particular Lyn, is mainly responsible for the antiviral activity of FGFR inhibitors. These results identify FGFR inhibitors as broad-spectrum antiviral agents and suggest the poorly studied Lyn kinase as a promising target for the treatment of viral infections.

Could chronic opioid use be an additional risk of hepatic damage in patients with previous liver diseases, and what is the role of microbiome?

Among illicit drugs, addiction from opioids and synthetic opioids is soaring in an unparalleled manner with its unacceptable amount of deaths. Apart from these extreme consequences, the liver toxicity is another important aspect that should be highlighted. Accordingly, the chronic use of these substances, of which fentanyl is the most frequently consumed, represents an additional risk of liver damage in patients with underlying chronic liver disease. These observations are drawn from various preclinical and clinical studies present in literature. Several downstream molecular events have been proposed, but recent pieces of research strengthen the hypothesis that dysbiosis of the gut microbiota is a solid mechanism inducing and worsening liver damage by both alcohol and illicit drugs. In this scenario, the gut flora modification ascribed to non-alcoholic fatty liver disease performs an additive role. Interestingly enough, HBV and HCV infections impact gut-liver axis. In the end, the authors tried to solicit the attention of operators on this major healthcare problem.

Inhibition of RAN attenuates influenza a virus replication and nucleoprotein nuclear export

Nuclear export of the viral ribonucleoprotein (vRNP) is a critical step in the influenza A virus (IAV) life cycle and may be an effective target for the development of anti-IAV drugs. The host factor ras-related nuclear protein (RAN) is known to participate in the life cycle of several viruses, but its role in influenza virus replication remains unknown. In the present study, we aimed to determine the function of RAN in influenza virus replication using different cell lines and subtype strains. We found that RAN is essential for the nuclear export of vRNP, as it enhances the binding affinity of XPO1 toward the viral nuclear export protein NS2. Depletion of RAN constrained the vRNP complex in the nucleus and attenuated the replication of various subtypes of influenza virus. Using in silico compound screening, we identified that bepotastine could dissociate the RAN-XPO1-vRNP trimeric complex and exhibit potent antiviral activity against influenza virus both in vitro and in vivo. This study demonstrates the important role of RAN in IAV replication and suggests its potential use as an antiviral target.

Targeting Ser78 phosphorylation of Hsp27 achieves potent antiviral effects against enterovirus A71 infection

A positive-sense (+) single-stranded RNA (ssRNA) virus (e.g. enterovirus A71, EV-A71) depends on viral polypeptide translation for initiation of virus replication after entry. We reported that EV-A71 hijacks Hsp27 to induce hnRNP A1 cytosol redistribution to initiate viral protein translation, but the underlying mechanism is still elusive. Here, we show that phosphorylation-deficient Hsp27-3A (Hsp27S15/78/82A) and Hsp27S78A fail to translocate into the nucleus and induce hnRNP A1 cytosol redistribution, while Hsp27S15A and Hsp27S82A display similar effects to the wild type Hsp27. Furthermore, we demonstrate that the viral 2A protease (2Apro) activity is a key factor in regulating Hsp27/hnRNP A1 relocalization. Hsp27S78A dramatically decreases the IRES activity and viral replication, which are partially reduced by Hsp27S82A. However, Hsp27S15A displays the same activity as the wild-type Hsp27. Peptide S78 potently suppresses EV-A71 protein translation and reproduction through blockage of EV-A71-induced Hsp27 phosphorylation and Hsp27/hnRNP A1 relocalization. A point mutation (S78A) on S78 impairs its inhibitory functions on Hsp27/hnRNP A1 relocalization and viral replication. Taken together, we demonstrate the importance of Ser78 phosphorylation of Hsp27 regulated by virus infection in nuclear translocation, hnRNP A1 cytosol relocation, and viral replication, suggesting a new path (such as peptide S78) for target-based antiviral strategy.

Acute Immunological Profile and Prognostic Biomarkers of Persistent Joint Pain in Chikungunya Fever: A Systematic Review

Chikungunya virus infection (CHIKV) increases the risk of persistent arthralgia; however, there is no consistent evidence regarding prognostic biomarkers of progression to chronic arthropathy. This systematic review provides an overview of currently available literature about the potential role of the acute immunologic response in predicting long-term joint pain in patients with a diagnosis of CHIKV. We searched for observational studies using the terms "chikungunya," "cytokines," "biomarkers," and "joint pain" in PubMed/MEDLINE, LILACS, Cochrane Library Plus, and SCOPUS databases, restricting to articles published in English and up to April 2024. PROSPERO registration number: CRD42021279400. Thirty-eight studies were selected for qualitative synthesis with a maximum duration from diagnosis to clinical evaluation of 60 months. The sample sizes ranged from 8 to 346 participants (age range: 0-90 years). We identified an immunologic profile during the acute phase of CHIKV that includes increased levels of proinflammatory cytokines (IFN-α, IFN-γ, IL-2R, IL-6, IL-7, and IL-8), anti-inflammatory cytokines (IL-1Ra and IL-4), chemokines (MCP-1, MIG, and IP-10) and growth factors (VEGF and G-CSF). Only one out of two studies reported differences in cytokine levels during the acute phase, predicting persistent joint pain at 20 months of follow-up. Also, persistence of anti-CHIKV IgG seemed to be a potential prognostic marker. The evidence suggests the existence of an inflammatory response in the acute phase of CHIKV that persists during its chronic phase; however, there is no unequivocal candidate set of biomarkers of progression toward long-term articular sequelae.

Burden of liver steatosis and liver fibrosis in a large cohort of people living with HIV

BACKGROUND

Liver steatosis (LS) and liver fibrosis (LF) can increase the risk of cardiovascular disease in people with HIV, but their prevalence and associated factors are poorly understood. This study aimed to assess the prevalence of and factors associated with LS and LF in a large cohort of people with HIV.

METHODS

We conducted a cross-sectional study of consecutive people with HIV attending the Clinic of Barcelona from September 2022 to September 2023, excluding those with chronic B or/and C hepatitis virus coinfection. LS was assessed using the Hepatic Steatosis Index (HSI) and Fatty Liver Index (FLI), and LF was assessed using the Non-Alcoholic Fatty Liver Disease Fibrosis Score (NFS), Fibrosis-4 score (FIB-4), and the European AIDS Clinical Society (EACS) algorithm in both the whole cohort (cohort 1) and in a specific cohort more susceptible to liver disease (cohort 2). We identified independent variables associated with LS and LF using logistic regression.

RESULTS

Cohort 1 included 4664 people with HIV; 76% and 37% of them had available HSI and FLI data, LS was present in 28% and 19%, respectively. LF risk was present in 1%, 2%, and 1% of people with HIV according to NFS, FIB-4, and EACS algorithm scores, respectively. Cohort 2 included 1345 people with HIV; 60% and 30% of them had available HSI and FLI data, LS affected 55% and 43% and LF 2%, 5%, or 3%, respectively. Factors associated with LS included current CD4 cell count, diabetes, and hypertension, whereas LF was associated with previous exposure to dideoxynucleoside drugs and current CD4 to LF. Current integrase strand transfer inhibitor (INSTI) therapy appeared protective for LF in cohort 1.

CONCLUSIONS

In this study, one in four people with HIV had LS, and the prevalence rose to one in two in those with cardiovascular risk factors. The prevalence of LF was low, but it should be considered in older people with HIV with low CD4 counts or high aspartate transaminase levels. A possible protective effect from INSTIs deserves further investigation.

TAAR1 and 5-HT1B receptor agonists attenuate autism-like irritability and aggression in rats prenatally exposed to valproic acid

Despite the rising prevalence of autism spectrum disorder (ASD), there remains a significant unmet need for pharmacotherapies addressing its core and associative symptoms. While some atypical antipsychotics have been approved for managing associated irritability and aggression, their use is constrained by substantial side effects. This study aimed firstly to develop behavioral measures to explore frustration, irritability and aggression phenotypes in the rat prenatal valproic acid (VPA) model of ASD. Additionally, we investigated the potential of two novel mechanisms, 5-HT1B and TAAR1 agonism, to alleviate these behaviors. Male offspring exposed to prenatal VPA were trained to achieve stable performance on a cued operant task, followed by pharmacological assessment in an operant frustration test, bottle brush test and resident intruder test. VPA exposed rats demonstrated behaviors indicative of frustration and irritability, as well as increased aggression compared to controls. The irritability-like behavior and aggression were further exacerbated in animals previously experiencing a frustrative event during the operant test. Single administration of the 5-HT1B agonist CP-94253 or TAAR1 agonist RO5263397 attenuated the frustration-like behavior compared to vehicle. Additionally, both agonists reduced irritability-like behavior under both normal and frustrative conditions. While CP-94253 reduced aggression in the resident intruder test under both conditions, RO5263397 only produced effects in rats that previously experienced a frustrative event. Our study describes previously uncharacterized phenotypes of frustration, irritability, and aggression in the rat prenatal VPA model of ASD. Administration of selective TAAR1 or 5-HT1B receptor agonists alleviated these deficits, warranting further exploration of both targets in ASD treatment.

Circulation of tick-borne pathogens in wildlife of the Republic of Korea

Habitat loss of wildlife and increased human activities in their habitat provide more opportunities for human-wild animal contact. These artificial environments influence humans by facilitating the transmission of tick-borne pathogens. Therefore, we aimed to detect and understand circulating tick-borne pathogens in the natural environment by analyzing blood and spleen samples of wild animals admitted to wildlife rescue centers in the Republic of Korea. In total, 376 samples were collected from 355 rescued wild animals immediately after their arrival or death. After DNA deoxyribonucleic acid and RNA extractions, reverse transcription polymerase chain reaction (RT-PCR) and nested PCR were conducted to detect target tick-borne pathogens. This study detected six positive samples of severe fever with thrombocytopenia syndrome virus (SFTSV), 146 Anaplasma phagocytophilum, 55 Anaplasma bovis, 19 Rickettsia spp., 45 Borrelia theileri, and 4 Bartonella schoenbuchensis. Among the positive samples, SFTSV was detected in one spleen sample from a Korean water deer, from which SFTSV was successfully isolated. After full genome sequencing, the L, M, and S segments all belonged to genotype B-3 and indicated 99.84 % ∼ 99.94 % similarity with SFTSV isolated from human serum. In conclusion, wild animals are potential reservoirs of tick-borne pathogens. Therefore, surveillance systems to prevent transmission among ticks, animals, and humans must be developed using the One Health concept.

Bivalent Omicron BA.1 vaccine booster increases memory B cell breadth and neutralising antibodies against emerging SARS-CoV-2 variants

BACKGROUND

Current literature informs us that bivalent vaccines will generate a broader serum neutralizing antibody response to multiple SARS-CoV-2 variants, but studies on how this breadth relates to the memory B cell (MBC) and T cell responses are sparse. This study compared breadth of neutralising antibody, and memory B and T cell responses to monovalent or a bivalent ancestral/Omicron BA.1 COVID-19 booster vaccine.

METHODS

At baseline and 1-month post-booster, neutralisation activity and frequencies of receptor binding domain (RBD)-specific MBCs and Spike-specific memory T cells were measured against a panel of variants.

FINDINGS

Both vaccines boosted neutralising antibodies to 5 variants - Wuhan-Hu-1, Delta, BA.1, BA.5 and JN.1, the latter of which had not yet emerged at the time of sample collection. The bivalent vaccine induced a significantly larger increase in nAb against BA.1 and JN.1. Both vaccines boosted RBD-specific MBC responses to Wuhan-Hu-1, Delta, BA.1 and BA.5 variants with a significantly greater increase for BA.1 in the bivalent group. The breadth of MBCs was significantly higher in those who received the bivalent boost and correlated with nAb breadth. Both vaccines significantly boosted Spike-specific T cell responses to the Wuhan-Hu-1 and BA.5 variants, but only the bivalent vaccine boosted BA.1 responses.

INTERPRETATION

These results suggest that the bivalent vaccine confers an advantage against future novel variants due to increased frequency of broadly reactive RBD-specific B cells.

FUNDING

Work supported by NSW Health for the NSW Vaccine, Infection and Immunology Collaborative (VIIM).

The Long-Term Health Outcomes of People Living with Perinatal Human Immunodeficiency Virus: A Scoping Review

Since the first reported cases of perinatally acquired human immunodeficiency virus (HIV) in 1982, a generation born with HIV has reached adulthood. The authors conducted a scoping review of PubMed and Google Scholar for articles published between January 2000 and June 2023 to assess the long-term, multisystem health outcomes of this population. Long-term health outcomes studied in this population pertain to the effects of perinatal HIV (PHIV) infection and life-long antiretroviral therapy on the endocrine, reproductive, psychosocial, neurobehavioral, immunologic, and cardiovascular systems. Holistic health of all body systems should be considered in the long-term care of people with PHIV.

Mechanism of PRRSV infection and antiviral role of polyphenols

Porcine reproductive and respiratory syndrome (PRRS) is associated with the endemic outbreak of fever, anorexia, and abortion in pregnant sows, resulting in an enormous economic impact on the global swine industry. Current mainstream prophylactic agents and therapies have been developed to prevent PRRSV infection; however, they have limited efficacy. Therefore, there is an urgent need to develop novel antiviral strategies to prevent PRRSV infection and transmission. The identification of new PRRSV entry mediators, such as MYH9 and HSPA8; viral apoptotic mimicry; and TIM-induced macropinocytosis, to facilitate infection has led to a novel molecular understanding of the PRRSV infection mechanism, which can be utilized in the development of prophylactic agents and therapies for PRRSV infection. Polyphenols, complex chemical molecules with abundant biological activities derived from microorganisms and plants, have demonstrated great potential for controlling PRRSV infection via different mechanisms. To explore new possibilities for treating PRRSV infection with polyphenols, this review focuses on summarizing the pathogenesis of PRRSV, reviewing the potential antiviral mechanisms of polyphenols against PRRSV, and addressing the challenges associated with the widespread use of polyphenols.

Viral coagulation: pushing the envelope

Many virus types affect the blood clotting system with correlations to pathology that range widely from thrombosis to hemorrhage linking to inflammation. Here we overview the intricate crosstalk induced by infection between proteins on the virus encoded by either the host or virus genomes, coagulation proteins, platelets, leukocytes, and endothelial cells. For blood-borne viruses with an outer covering acquired from the host cell, the envelope, a key player may be the cell-derived trigger of coagulation on the virus surface, tissue factor (TF). TF is a multifunctional transmembrane cofactor that accelerates factor (F)VIIa-dependent activation of FX to FXa, leading to clot formation. However, the nascent TF/FVIIa/FXa complex also facilitates G protein-coupled modulation of cells via protease-activated receptor 2. As a viral envelope constituent, TF can bypass the physiological modes of regulation, thereby initiating the activation of neighboring platelets, leukocytes, and endothelial cells. A thromboinflammatory environment is predicted due to feedback amplification in response to cellular release of cytokines, procoagulant proteins, neutrophil extracellular traps, and stimulus-induced accessibility of adhesive receptors, resulting in cellular aggregates. The pathobiological effects of thromboinflammation ultimately contribute to innate and adaptive immunity for viral clearance. In contrast, the preceding stages of viral infection may be enhanced via the TF-protease axis.

Gastrointestinal pathophysiology in long COVID: Exploring roles of microbiota dysbiosis and serotonin dysregulation in post-infectious bowel symptoms

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered an unprecedented public health crisis known as the coronavirus disease 2019 (COVID-19) pandemic. Gastrointestinal (GI) symptoms develop in patients during acute infection and persist after recovery from airway distress in a chronic form of the disease (long COVID). A high incidence of irritable bowel syndrome (IBS) manifested by severe abdominal pain and defecation pattern changes is reported in COVID patients. Although COVID is primarily considered a respiratory disease, fecal shedding of SARS-CoV-2 antigens positively correlates with bowel symptoms. Active viral infection in the GI tract was identified by human intestinal organoid studies showing SARS-CoV-2 replication in gut epithelial cells. In this review, we highlight the key findings in post-COVID bowel symptoms and explore possible mechanisms underlying the pathophysiology of the illness. These mechanisms include mucosal inflammation, gut barrier dysfunction, and microbiota dysbiosis during viral infection. Viral shedding through the GI route may be the primary factor causing the alteration of the microbiome ecosystem, particularly the virome. Recent evidence in experimental models suggested that microbiome dysbiosis could be further aggravated by epithelial barrier damage and immune activation. Moreover, altered microbiota composition has been associated with dysregulated serotonin pathways, resulting in intestinal nerve hypersensitivity. These mechanisms may explain the development of post-infectious IBS-like symptoms in long COVID. Understanding how coronavirus infection affects gut pathophysiology, including microbiome changes, would benefit the therapeutic advancement for managing post-infectious bowel symptoms.

Pathogenicity and virulence of O'nyong-nyong virus: A less studied Togaviridae with pandemic potential

O'nyong-nyong virus (ONNV) is a neglected mosquito-borne alphavirus belonging to the Togaviridae family. ONNV is known to be responsible for sporadic outbreaks of acute febrile disease and polyarthralgia in Africa. As climate change increases the geographical range of known and potential new vectors, recent data indicate a possibility for ONNV to spread outside of the African continent and grow into a greater public health concern. In this review, we summarise the current knowledge on ONNV epidemiology, host-pathogen interactions, vector-virus responses, and insights into possible avenues to control risk of further epidemics. In this review, the limited ONNV literature is compared and correlated to other findings on mainly Old World alphaviruses. We highlight and discuss studies that investigate viral and host factors that determine viral-vector specificity, along with important mechanisms that determine severity and disease outcome of ONNV infection.

Epstein-Barr Virus Antibodies and Autoimmune Diseases: A Bidirectional Mendelian Randomization Analysis

This study aims to evaluate the estimate of causal relationship between Epstein-Barr virus (EBV) antibody levels and autoimmune diseases (AIDs), such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), through bidirectional two-sample Mendelian randomization (MR) analysis. Despite 50 years of research into the link between EBV infection and AIDs, inconsistent results persist due to the complex mechanisms of EBV within the body. We utilized large-scale genome-wide association studies (GWAS) data from the Integrative Epidemiology Unit (IEU) Open GWAS Project database to conduct rigorous MR analysis, incorporating various sensitivity analyses to assess potential impacts and ensure robustness. EBV antibodies (including VCA-IgG, ZEBRA-IgG, EBNA-1-IgG, and EA-D-IgG) were used as exposure variables, whereas RA and SLE served as outcome variables. In the reverse analysis, RA and SLE were treated as exposure variables and EBV antibodies as outcome variables. When EBV antibodies are designated as the exposure variables, the random-effects inverse-variance weighted (IVW) analysis indicated a significant negative genetic causal relationship between EBV EA-D antibody levels and RA (p = 0.007, odds ratio [OR] = 0.700, 95% confidence interval [CI] = [0.539-0.907]). No significant genetic causal relationship was found between SLE and EBV antibody levels. When RA and SLE are designated as the exposure variables, the random-effects IVW analysis revealed significant positive genetic causal relationships between SLE and EBV ZEBRA antibody levels (p = 0.009, OR = 1.028, 95% CI = [1.007-1.050]) and EBV EA-D antibody levels (p = 0.005, OR = 1.032, 95% CI = [1.009-1.054]). No significant genetic causal relationship was observed between RA and EBV antibody levels. This study offers compelling evidence of a causal relationship between EBV antibody levels and AIDs through MR analysis. Our findings lay a new foundation and perspective for future research directions, clinical prognosis, and treatment.

Impact of Prolonged SARS-CoV-2 Viral Shedding on COVID-19 Disease Outcome and Viral Dynamics

This article aimed to review the current literature on the impact of continuous shedding of the COVID-19 virus in infected patients in relation to disease outcome variables and viral dynamics. Electronic databases PubMed, Google Scholar, and MedlinePlus were searched using relevant keywords, restricting the selection to thirty-two peer-reviewed articles and four gray literatures from the WHO websites. Findings from this study showed that several variables such as sex, age, immune status, treatments, and vaccines were found to affect the outcomes associated with the COVID-19 virus shedding. These findings highlight the need for further research using longitudinal whole-genome sequencing of the virus and its variants to increase the understanding.

Non-hepatotropic viral hepatitis: a narrative review

Non-hepatotropic viral hepatitis (NHVH) refers to acute hepatitis or acute liver failure caused by viruses that do not primarily target the liver. These viruses include the Epstein-Barr virus (EBV), cytomegalovirus (CMV), herpes simplex virus (HSV)-1 and -2, varicella zoster, parvovirus, adenovirus, adeno-associated virus type 2, measles, and severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2). The epidemiology, pathogenesis, and clinical manifestations of hepatitis due to hepatotropic viruses (hepatitis A-E) have been well studied. However, there is a paucity of data on NHVH due to its rarity, self-limiting clinical course, and vague presentation. NHVH can occur as an isolated illness or as part of a disseminated disease, and its clinical features range from self-limiting transaminitis to acute liver failure. This activity reviews the most common non-hepatotropic viruses (NHV), with a focus on their biology, etiopathogenesis, clinical manifestations, and management.

Sudden sensorineural hearing loss in children with dual positivity of serum anti-EBV IgM and anti-CMV IgM antibodies: a preliminary study

BACKGROUND

Sudden sensorineural hearing loss (SSNHL) is rare in children, and its etiology remains largely unknown, although viral infections seem to play an important role. The aim of this study is to report 5 children who experienced permanent SSNHL and had dual positivity of serum anti-Epstein-Barr virus (EBV) IgM and anti-Cytomegalovirus (CMV) IgM antibodies.

METHODS

The study was conducted in a third-level referral audiological center. The medical charts of children under age 14 who experienced SSNHL without hearing recovery between September 1, 2017 and August 31, 2020, were reviewed. These children had undergone diagnostic evaluations, including brain magnetic resonance imaging, serological testing, thrombophilia and autoimmunity screening, to find possible causes of SSNHL.

RESULTS

In all 5 patients identified, anti-EBV IgM, anti-CMV IgM and anti-CMV IgG antibodies were detected by chemiluminescent immunoassay (CLIA) immediately after the diagnosis of SSNHL, which occurred from 2 to 4 weeks after the onset of symptoms attributable to primary EBV infection. No abnormalities were demonstrated by coagulation and immunologic tests. Brain magnetic resonance imaging showed normal findings.

CONCLUSIONS

This study suggests that primary EBV infection should be considered one of the most likely causes of SSNHL without any hearing recovery in children. Therefore, a routine audiological examination should be recommended for children with virologically confirmed primary EBV infection at approximately 3-4 weeks after onset of symptoms and then repeated with periodic follow-up. Further studies on a wider number of children affected by SSNHL might clarify the possible pathogenetic role of this dual serological positivity.

Role of the Neanderthal Genome in Genetic Susceptibility to COVID-19: 3p21.31 Locus in the Spotlight

Since the outbreak of COVID-19, genome-wide association studies have tried to discover the role of genetic predisposition in the clinical variability of this viral infection. The findings of various investigations have led to several loci for COVID-19 genetic susceptibility. Among candidate regions, the 3p21.31 locus has been in the spotlight among scientists, as it can increase the risk of severe COVID-19 by almost two fold. In addition to its substantial association with COVID-19 severity, this locus is related to some common diseases, such as diabetes, malignancies, and coronary artery disease. This locus also harbors evolutionary traces of Neanderthal genomes, which is believed to be the underlying reason for its association with COVID-19 severity. Additionally, the inheritance of this locus from Neanderthals seems to be under positive selection. This review aims to summarize a collection of evidence on the 3p21.31 locus and its impact on COVID-19 outcomes by focusing on the risk variants originated from the Neanderthal genome. Moreover, we discuss candidate genes at this locus and the possible mechanisms by which they influence the progression of COVID-19 symptoms. Better insights into human genetic susceptibility to newly emerging diseases such as COVID-19 and its evolutionary origin can provide fundamentals for risk assessment of different populations as well as the development of personalized prevention and treatments based on genomic medicine.

A screening study on the detection strain of Coxsackievirus A6: the key to evaluating neutralizing antibodies in vaccines

The increasing incidence of diseases caused by Coxsackievirus A6 (CV-A6) and the presence of various mutants in the population present significant public health challenges. Given the concurrent development of multiple vaccines in China, it is challenging to objectively and accurately evaluate the level of neutralizing antibody response to different vaccines. The choice of the detection strain is a crucial factor that influences the detection of neutralizing antibodies. In this study, the National Institutes for Food and Drug Control collected a prototype strain (Gdula), one subgenotype D1, as well as 13 CV-A6 candidate vaccine strains and candidate detection strains (subgenotype D3) from various institutions and manufacturers involved in research and development. We evaluated cross-neutralization activity using plasma from naturally infected adults (n = 30) and serum from rats immunized with the aforementioned CV-A6 strains. Although there were differences between the geometric mean titer (GMT) ranges of human plasma and murine sera, the overall trends were similar. A significant effect of each strain on the neutralizing antibody test (MAX/MIN 48.0 ∼16410.3) was observed. Among all strains, neutralization of the S112 strain by 15 different sera resulted in higher neutralizing antibody titers (GMTS112 = 132.0) and more consistent responses across different genotypic immune sera (MAX/MIN = 48.0). Therefore, S112 may serve as a detection strain for NtAb testing in various vaccines, minimizing bias and making it suitable for evaluating the immunogenicity of the CV-A6 vaccine.

TCR-like bispecific antibodies toward eliminating infected hepatocytes in HBV mouse models

Therapeutics for eradicating hepatitis B virus (HBV) infection are still limited and current nucleos(t)ide analogs (NAs) and interferon are effective in controlling viral replication and improving liver health, but they cannot completely eradicate the hepatitis B virus and only a very small number of patients are cured of it. The TCR-like antibodies recognizing viral peptides presented on human leukocyte antigens (HLA) provide possible tools for targeting and eliminating HBV-infected hepatocytes. Here, we generated three TCR-like antibodies targeting three different HLA-A2.1-presented peptides derived from HBV core and surface proteins. Bispecific antibodies (BsAbs) were developed by fuzing variable fragments of these TCR-like mAbs with an anti-CD3ϵ antibody. Our data demonstrate that the BsAbs could act as T cell engagers, effectively redirecting and activating T cells to target HBV-infected hepatocytes in vitro and in vivo. In HBV-persistent mice expressing human HLA-A2.1, two infusions of BsAbs induced marked and sustained suppression in serum HBsAg levels and also reduced the numbers of HBV-positive hepatocytes. These findings highlighted the therapeutic potential of TCR-like BsAbs as a new strategy to cure hepatitis B.

Co-occurring Intimate Partner Violence, Mental Health, Human Immunodeficiency Virus, and Parenting Among Women: A Scoping Review

Little research exists on the human immunodeficiency virus (HIV)-intimate partner violence (IPV)-mental health (MH) syndemic impact on parenting. The objective of this scoping review is to identify and summarize the available evidence regarding the syndemic relationship between HIV or Acquired Immune Deficiency Syndrome (AIDS), IPV, and poor MH among mothers and caregivers who identify as women. We conducted the review according to the Joanna Briggs Institute and Preferred Reporting Items for Systematic reviews and meta-analyses extension for scoping reviews guidelines, a comprehensive search was conducted from 2001 to September 2023. The inclusion criteria targeted studies examining at least two of the HIV, IPV, or MH epidemics among participants and their syndemic impact on parenting. Both qualitative and quantitative studies were included. Covidence software was used to screen and extract data. Twenty-three studies were included in the analysis. Most of the studies were conducted in the United States. Furthermore, all the studies used quantitative research designs, with most being longitudinal. Most of the research was concentrated on the IPV-MH syndemic with no research found on the HIV-IPV syndemic impact on parenting. Research on the HIV-IPV-MH syndemic found that an HIV diagnosis exacerbated the negative impacts of IPV-MH on parenting. Research on IPV-MH showed that this syndemic significantly influences parenting, leading to less nurturing and more punitive behaviors. Studies did not find a direct association between IPV and harsh parenting practices, the relationship was mediated by poor MH. Studies examining the HIV-MH syndemic found that anxiety and maternal depression were the most frequent MH disorders. The review revealed that living with the different syndemics, (IPV-MH-HIV, HIV-MH, and IPV-MH) adversely affects parenting practices, resulting in harsher parenting.

Multidisciplinary rehabilitation with a focus on physiotherapy in patients with Post Covid19 condition: an observational pilot study

There is a lack of interventions that treat the Post-Covid-19 Condition (PCC) itself. Accordingly, treatment guidelines recommend physiotherapy interventions to alleviate symptoms and enhance functioning. In cases where unimodal treatments prove ineffective, non-organ-specific multidisciplinary bio-psycho-social rehabilitation (MBR) programs are a suitable option. In a pilot observational study with assessments at the entry and end of treatment we aimed to evaluate the feasibility of a 3-week day clinic MBR program and explore its effects on physical functioning in PCC patients with fatigue and reduced physical capacity. Patient selection was based on an interdisciplinary assessment involving a physician, a psychologist and a physiotherapist. Feasibility was determined based on full participation (≥ 8 of 9 days) and maintenance of stable endurance in the 6-Minute Walk Test (6MWT). From 37 patients included in the study, 33 completed the MBR (mean age: 43 ± 12 years, 73% female). Four patients discontinued the MBR, with two of them having reported deterioration of PCC symptoms. The 6MWT showed a numerical improvement from 501 ± 97 m to 512 ± 87 m, although it did not reach statistical significance. These results support the feasibility of outpatient MBR with a focus on active physiotherapy interventions in PCC patients with fatigue. This study aligns with previous research supporting the effectiveness of physiotherapy and rehabilitation in PCC patients. However, further research is needed to address possible different treatment responses and varying treatment approaches in subgroups of PCC patients.

Inflammatory, Hematological, and Biochemical Biomarkers in COVID-19 Patients

INTRODUCTION

There are few accurate prognostic indications of the illness's development and severity for COVID-19, despite certain biomarkers having been investigated. The unexpected nature of COVID-19's course, which can quickly progress from asymptomatic to life-threatening symptoms, lies at the heart of the disease's intricacy. Predicting SARS-CoV-2 pathogenicity through laboratory biomarkers and as such, identifying the patients' illness severity at the time of their initial admission would be crucial in improving patient care. In this study, we sought to evaluate the potential of hematological, biochemical, and inflammatory biomarkers in predicting the course of COVID-19 at a tertiary hospital in western Kenya.

METHODS

This cross-sectional study involved 48 COVID-19 patients (16 asymptomatic; 16 moderate symptomatic; and 16 severe symptomatic) and 48 age-sex-matched COVID-19-negative clients attending the Moi Teaching and Referral Hospital, Kenya. Demographic information, self-reported chronic illnesses, symptoms, and laboratory results were collected at recruitment.

RESULTS

Significantly, the severity of COVID-19 was associated with; hemoglobin (p < 0.0001), white blood cells (p = 0.0022), hematocrit (p < 0.0001), blood urea nitrogen (p = 0.01), blood sodium (p = 0.0002), potassium (p = 0.0483), C-reactive protein (p = 0.0002), and Lactate Dehydrogenase (p < 0.0001). Regression analysis of CRP revealed a strong positive correlation (p = 0.0006) whereas LDH revealed a weak positive correlation (p < 0.0001) with COVID-19 disease severity. Discriminative accuracy was highest when asymptomatic was compared to severe COVID-19 for CRP and LDH (AUC: 0.8867, 95% CI: 0.7532-1.000) and (AUC: 1.000, 95% CI: 1.000-1.000) respectively.

CONCLUSION

The hematological indices, inflammatory and biochemical biomarkers studied have the potential to predict the course of COVID-19. These parameters may be useful in helping design appropriate care for COVID-19 patients.

The Impact of SARS-CoV-2 on Liver Diseases and Potential Phytochemical Treatments

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has brought about numerous challenges. One of these challenges is the impact of SARS-CoV-2 on the liver. Although this virus primarily affects the lungs, it can induce elevated transaminase levels and the development of scar tissue in the liver, exacerbating preexisting liver conditions. Individuals with preexisting conditions, such as nonalcoholic fatty liver disease, alcohol-induced liver disease and hepatocellular carcinoma, face an increased risk of mortality from COVID-19. However, drugs currently used to treat COVID-19 have undesirable side effects, which make them unsuitable for patients with preexisting liver conditions. In this review, we explore the potential of phytochemicals, such as apigenin, berberine, curcumin, epigallocatechin-3-gallate, quercetin, resveratrol and silymarin, for treatment of the liver conditions, including nonalcoholic fatty liver disease, alcohol-induced liver disease and hepatocellular carcinoma. We also discuss significant associations between phytochemicals and COVID-19 by depicting their molecular interactions. Based on the discussed overlapping functions, it is important to assess the therapeutic efficacy of phytochemicals that possess hepatoprotective properties as potential alternative treatments for COVID-19.

Cross-sectional and longitudinal genotype to phenotype surveillance of SARS-CoV-2 variants over the first four years of the COVID-19 pandemic

BACKGROUND

Continued phenotyping and ongoing molecular epidemiology are important in current and future monitoring of emerging SARS-CoV-2 lineages. Herein we developed pragmatic strategies to track the emergence, spread and phenotype of SARS-CoV-2 variants in Australia in an era of decreasing diagnostic PCR testing and focused cohort-based studies. This was aligned to longitudinal studies that span 4 years of the COVID-19 pandemic.

METHODS

Throughout 2023, we partnered with diagnostic pathology providers and pathogen genomics teams to identify relevant emerging or circulating variants in the New South Wales (NSW) community. We monitored emerging variants through viral culture, growth algorithms, neutralisation responses and changing entry requirements defined by ACE2 and TMPRSS2 receptor use. To frame this in the context of the pandemic stage, we continued to longitudinally track neutralisation responses at the population level using pooled Intravenous Immunoglobulins (IVIG) derived from in excess of 700,000 donations.

FINDINGS

In antibodies derived from recent individual donations and thousands of donations pooled in IVIGs, we observed continued neutralisation across prior and emerging variants with EG.5.1, HV.1, XCT and JN.1 ranked as the most evasive SARS-CoV-2 variants. Changes in the type I antibody site at Spike positions 452, 455 and 456 were associated with lowered neutralisation responses in XBB lineages. In longitudinal tracking of population immunity spanning three years, we observed continued maturation of neutralisation breadth to all SARS-CoV-2 variants over time. Whilst neutralisation responses initially displayed high levels of imprinting towards Ancestral and early pre-Omicron lineages, this was slowly countered by increased cross reactive breadth to all variants. We predicted JN.1 to have a marked transmission advantage in late 2023 and this eventuated globally at the start of 2024. We could not attribute this advantage to neutralisation resistance but rather propose that this growth advantage arises from the preferential utilisation of ACE2 pools that cannot engage TMPRSS2 at its Collectrin-Like Domain (CLD).

INTERPRETATION

The emergence of many SARS-CoV-2 lineages documented at the end of 2023 was found to be initially associated with lowered neutralisation responses. This continued to be countered by the gradual maturation of cross-reactive neutralisation responses over time. The later appearance and dominance of the divergent JN.1 lineage cannot be attributed to a lack of neutralisation responses alone, and our data supports that its dominance is a culmination of both lowered neutralisation and changes in ACE2/TMPRSS2 entry preferences.

FUNDING

This work was primarily supported by Australian Medical Foundation research grants MRF2005760 (ST, GM & WDR), MRF2001684 (ADK and ST) and Medical Research Future Fund Antiviral Development Call grant (WDR), Medical Research Future Fund COVID-19 grant (MRFF2001684, ADK & SGT) and the New South Wales Health COVID-19 Research Grants Round 2 (SGT).

Evaluation of a non-nucleoside inhibitor of the RSV RNA-dependent RNA polymerase in translatable animals models

Respiratory Syncytial Virus (RSV) causes severe respiratory infections and concomitant disease resulting in significant morbidity and mortality in infants, elderly, and immunocompromised adults. Vaccines, monoclonal antibodies, and small-molecule antivirals are now either available or in development to prevent and treat RSV infections. Although rodent and non-rodent preclinical animal models have been used to evaluate these emerging agents, there is still a need to improve our understanding of the pharmacokinetic (PK)-pharmacodynamic (PD) relationships within and between animal models to enable better design of human challenge studies and clinical trials. Herein, we report a PKPD evaluation of MRK-1, a novel small molecule non-nucleoside inhibitor of the RSV L polymerase protein, in the semi-permissive cotton rat and African green monkey models of RSV infection. These studies demonstrate a strong relationship between in vitro activity, in vivo drug exposure, and pharmacodynamic efficacy as well as revealing limitations of the cotton rat RSV model. Additionally, we report unexpected horizontal transmission of human RSV between co-housed African green monkeys, as well as a lack of drug specific resistant mutant generation. Taken together these studies further our understanding of these semi-permissive animal models and offer the potential for expansion of their preclinical utility in evaluating novel RSV therapeutic agents.

COVID-19 and Oncofertility: No SARS-CoV-2 in Semen but Inflammation Seems to Affect Sperm Parameters

The COVID-19 pandemic, driven by SARS-CoV-2, led authorities to recommend halting assisted reproductive technology programs, focusing instead on fertility preservation, for cancer patients. The presence of SARS-CoV-2 in semen remains controversial. This multicentric prospective cohort study, conducted across 12 university medical centers, aimed to determine if SARS-CoV-2 is present in spermatozoa/seminal plasma in cancer patients by RT-PCR and to assess its impact on standard semen parameters. The levels of cytokines and TNF-α were measured in seminal fluid by ELISA. We enrolled 129 men who underwent sperm cryopreservation between July 7, 2020, and June 30, 2021. The 63 were included and tested for COVID-19 in nasal swab samples by RT-PCR and/or by serology. All patients were asymptomatic on the day of semen collection: 50 were uninfected, 8 had a positive nasal swab (PCR+) and 5 were seropositive. SARS-CoV-2 RNA was not detected in the seminal fluid or spermatozoa. Ejaculate volume was significantly lower in the PCR+ group compared to the uninfected group (median [IQR]: 2.6 mL [1.6-3.4] vs. 4.6 mL [2.6-5.2] p < 0.05). Total and progressive motility were lower in the PCR+ group compared to the seropositive group (32.5% [25.0-45.0] vs. 50% [49.0-55.0] p < 0.05, and 22.5% [10.0; 32.5] vs. 44.5% [40-49] p < 0.05). Higher TNF-α level was observed in the PCR+ group (1.9 pg/mL [0-3.9]) compared to the uninfected group (0 pg/mL [0-0.4]) p < 0.05. Although SARS-CoV-2 was not detected in the sperm samples of cancer patients who were PCR+, the infection appears to impact sperm parameters, likely due to inflammation.

Human Viral Oncoproteins and Ubiquitin-Proteasome System

Some human cancers worldwide may be related to human tumor viruses. Knowing, controlling, and managing the viruses that cause cancers remain a problem. Also, tumor viruses use ubiquitin-proteasome system (UPS) that can alter host cellular processes through UPS. Human tumor viruses cause persistent infections, due to their ability to infect their host cells without killing them. Tumor viruses such as Epstein-Barr virus, hepatitis C virus, hepatitis B virus, human papillomaviruses, human T cell leukemia virus, Kaposi's sarcoma-associated herpesvirus, and Merkel cell polyomavirus are associated with human malignancies. They interfere with the regulation of cell cycle and control of apoptosis, which are important for cellular functions. These viral oncoproteins bind directly or indirectly to the components of UPS, modifying cellular pathways and suppressor proteins like p53 and pRb. They can also cause progression of malignancy. In this review, we focused on how viral oncoproteins bind to the components of the UPS and how these interactions induce the degradation of cellular proteins for their survival.

DENV and ZIKV infection: Species specificity and broad cell tropism

Nearly one-third of countries worldwide have reported cases of Dengue virus (DENV) and Zika virus (ZIKV) infections, highlighting the significant threat these viruses pose to global public health. As members of the Flavivirus genus within the Flaviviridae family, DENV and ZIKV have demonstrated the ability to infect a wide range of cell lines from multiple species in vitro. However, the range of susceptible animal models is notably limited, and field studies indicate that their capacity to infect host organisms is highly restricted, with a very narrow range of target cells in vivo. The virus's ability to hijack host cellular machinery plays a crucial role in determining its cellular and species specificity. In this review, we examine how DENV and ZIKV exploit host cells to facilitate their replication, offering new insights that could inform the development of antiviral drugs and therapeutic targets.

Studying protein-protein interactions: Latest and most popular approaches

PPIs, or protein-protein interactions, are essential for many biological processes. According to the findings, abnormal PPIs have been linked to several diseases, such as cancer and infectious and neurological disorders. Consequently, focusing on PPIs is a path toward disease treatment and a crucial tool for producing novel medications. Many methods exist to investigate PPIs, including low- and high-throughput studies. Since many PPIs have been discovered using in vitro and in vivo experimental approaches, the use of computational methods to predict PPIs has grown due to the expanding scale of PPI data and the intrinsic complexity of interacting mechanisms. Recognizing PPI networks offers a systematic means of predicting protein functions, and pathways that are included. These investigations can help uncover the underlying molecular mechanisms of complex phenotypes and clarify the biological processes related to health and diseases. Therefore, our goal in this study is to provide an overview of the latest and most popular approaches for investigating PPIs. We also overview some important clinical approaches based on the PPIs and how these interactions can be targeted.

Neurological Sequelae of Post-COVID-19 Fatigue: A Narrative Review of Dipeptidyl Peptidase IV-Mediated Cerebrovascular Complications

Coronavirus disease 2019 (COVID-19) has been a global pandemic affecting millions of people's lives, which has led to 'post-COVID-19 fatigue'. Alarmingly, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) not only infects the lungs but also influences the heart and brain. Endothelial cell dysfunction and hypercoagulation, which we know occur with this infection, lead to thrombo-inflammation that can manifest as many myriad cardio-cerebrovascular disorders, such as brain fog, fatigue, cognitive dysfunction, etc. Additionally, SARS-CoV-2 has been associated with oxidative stress, protein aggregation, cytokine storm, and mitochondrial dysfunction in neurodegenerative diseases. Accordingly, the identification of molecular targets involved in these actions could provide strategies for preventing and treating this disease. In particular, the very common enzyme dipeptidyl peptidase IV (DPPIV) has recently been identified as a candidate co-receptor for the cell entry of the SARS-CoV-2 virus with its involvement in infection. In addition, DPPIV has been reported as a co-receptor for some viruses such as Middle East respiratory syndrome-coronavirus (MERS-CoV). It mediates immunologic reactions and diseases such as type 2 diabetes mellitus, obesity, and hypertension, which have been considered the prime risk factors for stroke among other types of cardio-cerebrovascular diseases. Unlike angiotensin-converting enzyme 2 (ACE2), DPPIV has been implicated in aggravating the course of infection due to its disruptive effect on inflammatory signaling networks and the neuro-glia-vascular unit. Regarding the neurological, physiological, and molecular grounds governing post-COVID-19 fatigue, this review focuses on DPPIV as one of such reasons that progressively establishes cerebrovascular grievances following SARS-CoV infection.

Effect of Pregenomic RNA on the Mechanical Stability of HBV Capsid by Coarse-Grained Molecular Simulations

Hepatitis B virus (HBV) is a double-stranded DNA virus, but its life cycle involves an intermediate stage, during which pregenomic RNA (pgRNA) is encapsulated in the capsid and then reverse-transcribed into the minus DNA strand. These immature HBV virions are the key target for antiviral drug discovery. In this study, we investigate the flexibility and mechanical stability of the HBV capsid containing pgRNA by employing residue-resolved coarse-grained molecular dynamics simulations. The results showed that the presence of pgRNA tends to decrease the overall flexibility of the capsid. In addition, the symmetrically arranged subunits of the capsid show asymmetry in the dominant modes of the conformational fluctuations with or without the presence of pgRNA. Furthermore, the simulations revealed that the presence of pgRNA enhances the overall mechanical stability of the virion particle. Electrostatic interactions between the disordered CTD of capsid and pgRNA were found to play a crucial role in modulating viral mechanical stability. Decreasing the electrostatic interactions by CTD phosphorylation or high salt concentration significantly reduces the mechanical stability of the HBV capsid containing pgRNA. Finally, the 2-fold symmetric sites have been proposed to be the most vulnerable to rupture during the initial stages of capsid disassembly. These findings could enhance our understanding of the physical basis of viral invasion and provide valuable insights into the development of antiviral drugs.

Outcome of SARS-CoV-2 reinfection depends on genetic background in female mice

Antigenically distinct SARS-CoV-2 variants increase the reinfection risk for vaccinated and previously exposed population due to antibody neutralization escape. COVID-19 severity depends on many variables, including host immune responses, which differ depending on genetic predisposition. To address this, we perform immune profiling of female mice with different genetic backgrounds -transgenic K18-hACE2 and wild-type 129S1- infected with the severe B.1.351, 30 days after exposure to the milder BA.1 or severe H1N1. Prior BA.1 infection protects against B.1.351-induced morbidity in K18-hACE2 but aggravates disease in 129S1. H1N1 protects against B.1.351-induced morbidity only in 129S1. Enhanced severity in B.1.351 re-infected 129S1 is characterized by an increase of IL-10, IL-1β, IL-18 and IFN-γ, while in K18-hACE2 the cytokine profile resembles naïve mice undergoing their first viral infection. Enhanced pathology during 129S1 reinfection cannot be attributed to weaker adaptive immune responses to BA.1. Infection with BA.1 causes long-term differential remodeling and transcriptional changes in the bronchioalveolar CD11c+ compartment. K18-hACE2 CD11c+ cells show a strong antiviral defense expression profile whereas 129S1 CD11c+ cells present a more pro-inflammatory response upon restimulation. In conclusion, BA.1 induces cross-reactive adaptive immune responses in K18-hACE2 and 129S1, but reinfection outcome correlates with differential CD11c+ cells responses in the alveolar space.

Zika virus remodels and hijacks IGF2BP2 ribonucleoprotein complex to promote viral replication organelle biogenesis

Zika virus (ZIKV) infection causes significant human disease that, with no approved treatment or vaccine, constitutes a major public health concern. Its life cycle entirely relies on the cytoplasmic fate of the viral RNA genome (vRNA) through a fine-tuned equilibrium between vRNA translation, replication, and packaging into new virions, all within virus-induced replication organelles (vROs). In this study, with an RNA interference (RNAi) mini-screening and subsequent functional characterization, we have identified insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) as a new host dependency factor that regulates vRNA synthesis. In infected cells, IGF2BP2 associates with viral NS5 polymerase and redistributes to the perinuclear viral replication compartment. Combined fluorescence in situ hybridization-based confocal imaging, in vitro binding assays, and immunoprecipitation coupled to RT-qPCR showed that IGF2BP2 directly interacts with ZIKV vRNA 3' nontranslated region. Using ZIKV sub-genomic replicons and a replication-independent vRO induction system, we demonstrated that IGF2BP2 knockdown impairs de novo vRO biogenesis and, consistently, vRNA synthesis. Finally, the analysis of immunopurified IGF2BP2 complex using quantitative mass spectrometry and RT-qPCR revealed that ZIKV infection alters the protein and RNA interactomes of IGF2BP2. Altogether, our data support that ZIKV hijacks and remodels the IGF2BP2 ribonucleoprotein complex to regulate vRO biogenesis and vRNA neosynthesis.

Association between human herpesviruses infections and childhood neurodevelopmental disorders: insights from two-sample mendelian randomization analyses and systematic review with meta-analysis

BACKGROUND

The potential roles of viral infections in neurodevelopmental disorders (NDDs) have been suggested based on previous studies. Given the high prevalence of human herpesviruses (HHVs), the associations between HHVs infection and the risk of NDDs warrant explored.

METHODS

Our study employs a two-sample Mendelian randomization (MR) analysis and systematic review with meta-analysis to investigate whether genetically predicted HHVs infection are linked to three main childhood NDDs-autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and Tourette syndrome (TS). We utilized genetic variants associated with HHV infections in genome-wide association study (GWAS) summary datasets of European populations to establish instrumental variables and statistics for three NDDs obtained from Psychiatric Genomics Consortium. MR analysis was performed using inverse-variance weighted, MR Egger, weighted median, simple median, weighted mode, and MR-PRESSO. In addition, publications associating HHVs infection with three NDDs were systematically searched using PubMed, Web of Science, and three Chinese databases for meta-analyses.

RESULTS

The MR results found no evidence to support a link between genetically predicted HHVs infection and the risk of NDDs based on existing datasets. Twenty-seven observational studies on children with HHVs infection and NDDs were considered eligible. Meta-analysis showed that cytomegalovirus and HHV-6 infection were related with ASD, while Epstein-Barr virus and cytomegalovirus infection were associated with TD in Chinese population.

CONCLUSIONS

These results contribute to a comprehensive understanding of the possibilities underlying HHV infections in affecting childhood NDDs. Further research is necessary to include larger and more robust statistics of HHV infections and NDDs.

TRIAL REGISTRATION

This systematic review was registered at PROSPERO as CRD42024554169. Retrospectively registered 26 July 2024.

Gut microbiome dysbiosis and immune activation correlate with somatic and neuropsychiatric symptoms in COVID-19 patients: Microbiome dysbiosis linked to COVID-19 symptoms

COVID-19 patients often exhibit altered immune responses and neuropsychiatric symptoms during hospitalization. However, the potential interactions with gut microbiome profiles have not been fully characterized. Here, COVID-19 disease severity was classified as low (27.4%), moderate (29.8%), and critical (42.8%). Fever (66.1%) and cough (55.6%) were common symptoms. Additionally, 27.3% reported somatic symptoms, 27.3% experienced anxiety, 39% had depressive symptoms, and 80.5% reported stress. Gut microbiome profiling was performed using full-length 16S rRNA gene sequencing. Elevated interleukin-6 levels were observed in the most severe cases, indicating systemic inflammation. Reduced gut bacterial diversity was more pronounced in women and obese patients and correlated with higher disease severity. The presence of the genus Mitsuokella was significantly associated with increased physical, stress, anxiety, and depressive symptoms, and Granulicatella with critically ill patients. These findings suggest a link between mental health status, systemic inflammation, and gut dysbiosis in COVID-19 patients, emphasizing the potential of microbiome-targeted therapies to improve recovery and reduce severe complications.

The diagnostic value of peripheral blood lymphocyte testing in children with infectious mononucleosis

OBJECTIVE

To investigate the diagnostic value of peripheral blood lymphocyte testing in children with infectious mononucleosis (IM).

METHODS

A total of 135 children with IM as the IM group and 100 healthy volunteers as the healthy group were included in this retrospective study. Peripheral blood lymphocyte subsets marked as CD3+, CD4+, CD8+, CD16 + CD56+, and CD19 + in the peripheral blood were quantified using flow cytometry. Statistical analysis was performed using the chi-square test, Kruskal-Wallis test, AUROC curve, and Kappa consistency test to assess the diagnostic value of these markers in IM.

RESULTS

The AUROC curve for CD8 + cells and for CD4+/CD8 + ratios both achieved a value of 1 with the sensitivity and specificity of 100% (P<0.001). The Kappa coefficients were 1 for CD8+, CD4+/CD8 + ratios and the combined EBV analysis, indicating a 100% consistency with the clinical diagnosis. Significant differences were also observed in the CD3+, CD4+, CD16 + CD56+, and CD19 + lymphocyte subsets between the IM group and the healthy group (P<0.05).

CONCLUSION

The evaluation of CD8 + and CD4+/CD8 + ratios in peripheral blood lymphocytes represents a significant advancement in the diagnosis of IM. Peripheral blood lymphocyte testing offers a reliable, sensitive, and specific diagnostic tool to enhance the clinical management of children with IM.

Immunosenescence: A new direction in anti-aging research

The immune system is a major regulatory system of the body, that is composed of immune cells, immune organs, and related signaling factors. As an organism ages, observable age-related changes in the function of the immune system accumulate in a process described as 'immune aging. Research has shown that the impact of aging on immunity is detrimental, with various dysregulated responses that affect the function of immune cells at the cellular level. For example, increased aging has been shown to result in the abnormal chemotaxis of neutrophils and decreased phagocytosis of macrophages. Age-related diminished functionality of immune cell types has direct effects on host fitness, leading to poorer responses to vaccination, more inflammation and tissue damage, as well as autoimmune disorders and the inability to control infections. Similarly, age impacts the function of the immune system at the organ level, resulting in decreased hematopoietic function in the bone marrow, a gradual deficiency of catalase in the thymus, and thymic atrophy, resulting in reduced production of related immune cells such as B cells and T cells, further increasing the risk of autoimmune disorders in the elderly. As the immune function of the body weakens, aging cells and inflammatory factors cannot be cleared, resulting in a cycle of increased inflammation that accumulates over time. Cumulatively, the consequences of immune aging increase the likelihood of developing age-related diseases, such as Alzheimer's disease, atherosclerosis, and osteoporosis, among others. Therefore, targeting the age-related changes that occur within cells of the immune system might be an effective anti-aging strategy. In this article, we summarize the relevant literature on immune aging research, focusing on its impact on aging, in hopes of providing new directions for anti-aging research.

Identification of Host Factors Interacting with Movement Proteins of the 30K Family in Nicotiana tabacum

The interaction of viral proteins with host factors represents a crucial aspect of the infection process in plants. In this work, we developed a strategy to identify host factors in Nicotiana tabacum that interact with movement proteins (MPs) of the 30K family, a group of viral proteins around 30 kDa related to the MP of tobacco mosaic virus, which enables virus movement between plant cells. Using the alfalfa mosaic virus (AMV) MP as a model, we incorporated tags into its coding sequence, without affecting its functionality, enabling the identification of 121 potential interactors through in vivo immunoprecipitation of the tagged MP. Further analysis of five selected candidates (histone 2B (H2B), actin, 14-3-3A protein, eukaryotic initiation factor 4A (elF4A), and a peroxidase-POX-) were conducted using bimolecular fluorescence complementation (BiFC). The interactions between these factors were also studied, revealing that some form part of protein complexes associated with AMV MP. Moreover, H2B, actin, 14-3-3, and eIF4A interacted with other MPs of the 30K family. This observation suggests that, beyond functional and structural features, 30K family MPs may share common interactors. Our results demonstrate that tagging 30K family MPs is an effective strategy to identify host factors associated with these proteins during viral infection.