Journal of NeuroVirology最新文献

COVID-19 was a nightmare in humankind's history that challenged our advanced medical technology. All credit goes to the researchers who played a crucial role in curbing COVID-19 and proved our medical technology supremacy. However, COVID-19 has left some mysterious scars on human well-being. It is believed that COVID-19 has a significant negative impact on various cardiovascular (CVS) and central nervous system (CNS) diseases, especially in the case of CNS diseases like Alzheimer's. Surprisingly, COVID-19 affects the respiratory system, whereas Alzheimer's disease (AD) alters brain function. To explain this phenomenon, several hypotheses were proposed, but the mechanism needs to be clearly understood. Another critical thing to be concerned about is that COVID-19 will worsen pre-existing conditions and lead to the onset of AD. In the race to curb COVID-19, the invention of vaccines was speeded up, and it is necessary to fight against COVID-19. However, postvaccination follow-up is mandatory when an individual is a victim of AD. In this review article, we compiled the various dreadful effects of the COVID-19 virus on AD, the Post effects of the virus on AD, and the effect of the COVID-19 vaccination on AD. This article provides a new direction for research concerning COVID-19 and AD.

Progressive Multifocal Leukoencephalopathy (PML) is a rare opportunistic infection of the central nervous system (CNS) caused by human polyomavirus JC virus, with high mortality rate in people living with HIV (PLWH), without an effective specific treatment beside combined antiretroviral therapy (cART). The use of Pembrolizumab, an inhibitor of the Programmed cell death protein 1 (PD-1) receptor on T cells, has been associated with decreased viral clearance. Aim of this study is to evaluate clinical course of PLWH affected by PML treated with pembrolizumab. We report four consecutive PLWH with clinical and radiological evidence of PML and JCV-DNA detection in cerebrospinal fluid (CSF). Pembrolizumab was administered to all four PLWH alongside cART. Radiological and laboratory follow-up were performed at the end of the medical protocol. Clinically, 3 out of 4 PLWH showed an improvement in neurological deficits, partially reacquiring the lost functions, and they are alive at 3.5 years, 14 months, and 9 months, respectively; the fourth patient died shortly after treatment due to worsening respiratory conditions. In all the PLWH completing treatment, a decrease of about 80-90% of the specific PD-1 activity was observed. Prolonged survival and stabilization of radiological findings have been observed, along with clinical improvement and partial recovery of acquired deficits in 3 out of 4 PLWH. In addition, a decrease in anti-PD-1 expression has also been observed, suggesting a link between the therapy and the success achieved. Given the small sample and conflicting evidence in the existing literature, further investigation is needed to assess its effectiveness.

The role of plasma exosomes from people living with HIV (PLWH) with HAND in the phenotypic profile of uninfected monocytes remains unknown. We hypothesized that these exosomes influence the CD14/CD16 phenotypical profile of uninfected monocytes in a time-dependent manner. Exosomes were collected via ultracentrifugation from the plasma of women living with HIV (WLWH) and healthy controls stratified according to their cognition into normal cognition (NC) or symptomatic neurocognitive impairment (SNI) groups. Monocyte subsets were identified via flow cytometry by using anti-CD14 and anti-CD16 fluorescent antibodies. Exosome uptake and changes in the percentages of monocyte subpopulations were analyzed from 1 to 24 h. The following results were obtained. (1) The uptake of HIV-negative exosomes by total uninfected monocytes was observed at 24 h, whereas the uptake of HIV-positive exosomes was observed at an earlier time point at 6 h. (2) HIV-positive exosomes significantly decreased the percentage of classical monocytes and increased intermediate and nonclassical monocytes at 24 h. (3) The uptake of NC exosomes was observed at an early time point at 6 h compared with SNI in all of the monocyte subsets. (4) Higher percentages of monocyte subsets were observed when cells were exposed to NC exosomes at 1 h, 6 h, or 24 h than when monocytes were exposed to exosomes from SNI patients. Our findings may help to identify new targets and molecular mechanisms that are involved in the pathogenesis of HAND.

HIV-associated neurocognitive disorder (HAND) is a complication of chronic inflammation caused by HIV infection that impairs cognitive and motor functions. HAND can occur at any age, regardless of the duration of infection, even in people living with HIV (PLWH) whose blood viral load is controlled by antiretroviral therapy. The diagnosis of HAND requires a battery of neuropsychological tests, which is time-consuming and burdensome, limiting its effectiveness for screening PLWH. Here, we aimed to identify biomarkers for quantitatively diagnosing and screening for HAND using minimally invasive blood tests. Neuronal-derived exosomes (neuroexosomes) were isolated from the peripheral blood of PLWH, and the transcriptomes of their microRNAs (miRNAs) were analyzed. We identified five upregulated miRNAs (hsa-miR-16-5p, hsa-miR-26a-3p, hsa-92a-3p, hsa-miR-103a-3p, and hsa-miR-185-5p), and two downregulated miRNA (hsa-miR-3613-3p and hsa-miR-4668-5p) in PLWH diagnosed with HAND (HAND PLWH). Functional analysis of five miRNAs whose expression levels increased in HAND PLWH using the database showed that these miRNAs are involved in motor proteins and endocytosis, which are associated with nerve function. The expression levels of hsa-miR-16-5p, hsa-miR-103a-3p, and hsa-miR-185-5p were significantly higher than those in the non-HIV controls and non-HAND PLWH, suggesting that these miRNAs are potential biomarkers for HAND. Since there were no changes in known dementia miRNA biomarkers in HAND PLWH, the miRNAs identified in this study will allow for early differentiation of HAND.

Effective neuropsychological assessment of people with HIV (PWH) in low- and middle-income countries (LMICs) is hampered by the unavailability of adequate test norms. We aimed to: (1) develop demographically-corrected (regression-based) South African (SA) normative data for an HIV appropriate neuropsychological test battery for Xhosa home-language speakers; (2) compare the utility of those norms to that of (i) internal standardization norms and (ii) US test publisher norms; and (3) determine the criterion validity of the newly-developed norms. 114 controls and 102 demographically comparable Xhosa home-language people living with HIV completed a well-establised, standard HIV neuropsychological test battery assessing seven cognitive domains. Using a common performance metric (z-score), we compared control and PWH test performance and examined the extent to which the three different normative datasets embedded demographic effects e.g., education. Using internal standardization norms, analyses detected medium-sized correlations of overall test performance with age and education. Correlations were fully corrected for by the newly-developed demographically-corrected norms. Using demographically-corrected norms, PWH performed significantly more poorly than controls in five cognitive domains, whereas using internal standardization norms and test-publisher norms, PWH performed significantly more poorly than controls in one and two domains, respectively. Demographically-corrected norms estimated 43.1% of PWH were cognitively impaired; these estimates were 22.5% using test-publisher norms and 19.6% using internal standardization norms. Demographically-corrected SA norms were more sensitive to cognitive impairment in PWH than the other sets of norms. Expansion of this regression-based method to create population-appropriate norms will benefit research and clinical practice in LMICs.

Zika virus (ZIKV) is a neurotropic flavivirus that induces congenital Zika syndrome and neurodevelopmental disorders. Given that ZIKV can infect and replicate in neural cells, neurological complications in adult brain are also observed. Glial cells may emerge to delay and/or prevent the development of ZIKV-induced neurodegeneration. These cells actively participate in metabolic, inflammatory and redox processes, and consequently, in the pathophysiology of neurodegenerative diseases, including diabetic encephalopathy. In this sense, changes in glucose metabolism can support the inflammatory activity of astroglial cells; however, the effects of increased glucose concentration during ZIKV infection have not yet been explored in astroglial cells. Here, we evaluated functional parameters of astroglial cells exposed to ZIKV upon normal and high glucose concentrations, focusing on inflammatory profile, oxidative stress, and expression of critical genes for astroglial functions. High glucose potentiated the pro-inflammatory and oxidative effects of ZIKV, as well as potentiated the downregulation of signaling pathways, such as Nrf-2 (nuclear factor erythroid derived 2 like 2), sirtuin 1 (SIRT1), peroxisome proliferator activated receptor gamma coactivator 1-alpha (PGC-1α), and poly (ADP-ribose) polymerase (PARP). In summary, our results suggest that high glucose can favor the activation of inflammatory signaling while impairing cytoprotective pathways in astroglial cells exposed to ZIKV and reinforce the hypothesis that this virus is highly neurotrophic, with significant impact in glial cells.

Tick-borne encephalitis (TBE) is a vector-borne disease caused by the TBE virus (TBEV). Although TBEV infection in children seems to lead to a milder clinical presentation, data in pediatrics are scarce. We aimed to determine the incidence of TBE among pediatric patients presenting with neurological symptoms from January 2020 to December 2022 at the University Hospital of Strasbourg (HUS), France. 462 Patients for whom cerebrospinal fluid (CSF) samples were available were included and categorized by age group: 0-4 years, 5-9 years, and 10-15 years. Serological tests and RT-PCR were carried out on the CSF samples, and the positive results were confirmed by seroneutralization test (SNT). A CSF IL-6 assay was performed for confirmed cases. We retrospectively detected four TBE-confirmed cases. We found an incidence of 1.51 cases per 100,000 inhabitants in the pediatric population over 2020-2022. The four cases were girls, with a median age of 10.4 years. The symptoms appeared in two cases in October 2022, outside the seasonal peak. Signs of encephalitis were present in two patients, and persistent sequelae were reported in three patients and two more than a year after hospitalization. None of the confirmed cases were vaccinated against TBEV despite frequent exposure to ticks. Intrathecal concentrations of IL-6 were increased for two patients; for one patient, the concentration was significantly higher than the values found in control cases. Our data highlight the need for early diagnosis and long-term follow-up of affected children and raise questions about the evolution of vaccination recommendations.

Choroid plexus (CP) inflammation can be quantified in vivo with MRI in people with multiple sclerosis (pwMS). It remains unknown whether Epstein Barr Virus (EBV) is related to CP changes. Total of 170 pwMS (116 relapsing-remitting; RRMS and 54 progressive MS; PMS) underwent MRI examination and measurement of humoral anti-EBV response. CP volume and CP pseudo-T2 (pT2), a relaxation time indicative of edema and neuroinflammation, were measured. Moreover, anti-EBV nuclear antigen-1 (EBNA-1) IgG and anti-EBV capsid antigen (VCA) IgG antibodies were measured. The PMS group had greater CP pT2 value when compared to RRMS (1120ms vs. 954ms, p = 0.037). After adjusting for age and therapy effects, higher CP pT2 values were associated with higher anti-EBNA-1 IgG levels only in PMS (r = 0.352, p = 0.015). Higher Anti-EBV humoral response in pwMS may be associated with increased CP neuroinflammatory changes and may be more relevant for the later chronic stage of the disease. Large-scale studies should investigate whether these findings are generalizable to all types of progressive MS.

Human endogenous retroviruses (HERVs) involvement in neurological diseases has been extensively documented, although the etiology of HERV reactivation remains unclear. MicroRNAs represent one of the potential regulatory mechanisms of HERV reactivation. We identified fourteen microRNAs predicted to bind the HERV-K transcript, and subsequently analyzed for their gene expression levels alongside those of HERV-K. We documented an increased expression of four microRNAs in patients with Parkinson's disease compared to healthy controls, which correlated with a downregulation of HERV-K transcripts. We hypothesize that specific microRNAs may bind to HERV-K transcripts, leading to its downregulation.

After the Zika virus (ZIKV) epidemic in Brazil, ZIKV infections were linked to damage to the central nervous system (CNS) and congenital anomalies. Due to the virus's ability to cross the placenta and reach brain tissue, its effects become severe, leading to Congenital Zika Syndrome (CZS) and resulting in neuroinflammation, microglial activation, and secretion of neurotoxic factors. The presence of ZIKV triggers an inadequate fetal immune response, as the fetus only has the protection of maternal antibodies of the Immunoglobulin G (IgG) class, which are the only antibodies capable of crossing the placenta. Because of limited understanding regarding the long term consequences of ZIKV infection and the involvement of maternal antibodies, this study sought to assess the impact of the ZIKV + IgG⁺complex on murine microglial cells. The cells were exposed to ZIKV, IgG antibodies, and the ZIKV + IgG⁺complex for 24 and 72 h. Treatment-induced cytotoxic effects were evaluated using the cell viability assay, oxidative stress, and mitochondrial membrane potential. The findings indicated that IgG antibodies exhibit cytotoxic effects on microglia, whether alone or in the presence of ZIKV, leading to compromised cell viability, disrupted mitochondrial membrane potential, and heightened oxidative damage. Our conclusion is that IgG antibodies exert detrimental effects on microglia, triggering their activation and potentially disrupting the creation of a neurotoxic environment. Moreover, the presence of antibodies may correlate with an elevated risk of ZIKV-induced neuroinflammation, contributing to long-term CNS damage.