CRISPR technology is emerging as a promising therapeutic approach for eliminating chronic viral infections, such as herpesviruses and HIV. Here, for the first time, we demonstrate in vitro that CRISPR can be used to excise the HTLV-1 genome and reduce proviral loads in PBMCs from HAM/TSP (HTLV-1-associated myelopathy/tropical spastic paraparesis) patients. Single treatment with CRISPR-RNP (ribonucleoprotein) complexes composed of two gRNAs targeting the HTLV-1 env gene and 3’LTR sequences resulted in excision of a 2613 bp segment of the proviral genome, spanning tax and HBZ genes, without detectable off-target activity. Furthermore, CRISPR treatment led to over 50
Hantavirus infection is primarily associated with hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS), with predominant renal and pulmonary involvement. However, neurological manifestations affecting both the central nervous system (CNS) and peripheral nervous system (PNS) are increasingly recognized. We conducted a narrative review of the literature to summarize the current evidence regarding hantavirus-associated neurological involvement. Reported CNS manifestations included encephalitis, encephalopathy, seizures, meningitis, neurocognitive alterations, posterior reversible encephalopathy syndrome, transverse myelitis, and cerebral hemorrhage. PNS involvement appeared less frequent and included Guillain–Barré syndrome, cranial nerve palsies, neuropathic pain, and sensory disturbances. Neuroimaging findings were heterogeneous, while cerebrospinal fluid analysis often demonstrated nonspecific inflammatory changes. Advanced molecular techniques such as metagenomic next-generation sequencing may improve diagnostic sensitivity, particularly in immunocompromised patients. Current evidence suggests that neurological involvement may result from endothelial dysfunction, neuroinflammation, immune-mediated injury, blood–brain barrier disruption, and, in selected cases, direct viral neuroinvasion. Greater clinical awareness is needed to improve recognition of neurological complications during hantavirus infection. Further prospective studies are required to better define the epidemiology, pathogenesis, and optimal diagnostic approaches of hantavirus-associated neurological disease.
Zika virus (ZIKV) infections have been linked to severe neurological disorders, including microcephaly and Guillain-Barré syndrome in humans as well as mouse models of ZIKV infection. Despite the association, the mechanisms underlying ZIKV-induced neuropathology remain incompletely understood. We have recently shown that antigen independent CD8+ T cells mediate neurological disease in ZIKV-infected mice independent of the amount of infectious virus in the CNS. To further investigate the role of brain viral load and lymphocytes in ZIKV infection we studied the viral kinetics, pathology, and immune responses of ZIKV-infected NOD-Rag1−/−Il2rg−/− mice, which are deficient in lymphoid cells. Despite prolonged high viral titers in the brain, NOD-Rag1−/−IL2rg−/− mice did not develop neurological symptoms following ZIKV infection, contrasting with the infection outcomes of Ifnar1−/− mice which exhibit paralysis despite lower viral load. Notably, we observed significant differences in brain myeloid cells in the presence or absence of lymphoid cells. While Ifnar1−/− mice showed robust infiltration of CD45hiCD11b+ cells in the brain, lymphocyte-deficient NOD-Rag1−/−IL2rg−/− mice exhibited reduced recruitment and activation of these cells. Additionally, we found that CD45hiCD11b+ cells displayed a more inflammatory phenotype in Ifnar1−/− mice compared to NOD-Rag1−/−IL2rg−/− mice. Our study highlights the complex interplay between the immune system and viral infection in ZIKV-induced neuropathology and underscores the importance of considering immune responses in the development of therapeutic interventions for ZIKV.
Brain health disorders (BHDs) remain a concern for people with HIV (PWH) despite antiretroviral therapy access and viral suppression. The contribution of HIV to brain health is often obscured by comorbidities in high-income settings which are less prevalent in sub-Saharan Africa. Neurofilament light chain (NfL), a biomarker of axonal injury, may offer insight into underlying mechanisms. 338 virally-suppressed PWH and 250 people without HIV (PWoH) completed a Research Domain Criteria-informed battery assessing cognitive, sensorimotor, and social processing systems. Demographically-adjusted norms were derived from PWoH. Serostatus differences in impairment (≥ 1SD below the mean) were examined using multivariable logistic regression. Additional models examined associations between NfL (plasma, cerebrospinal fluid [CSF]) and task performance. PWH were similar to PWoH in age (43.9 vs. 43.5yrs), sex (female, 54 vs. 46
West Nile virus neuroinvasive disease (WNND) most commonly presents as meningitis, encephalitis, or acute flaccid paralysis, with variable neuroimaging findings. While MRI abnormalities classically involve deep gray matter and brainstem structures, hemorrhagic manifestations are rarely reported. We report a 77-year-old woman who presented with rapidly progressive altered mental status following a brief febrile prodrome. Cerebrospinal fluid studies demonstrated a lymphocytic pleocytosis consistent with aseptic meningitis. Brain MRI revealed an acute lacunar infarct and diffuse cerebral microhemorrhages initially concerning for cerebral amyloid angiopathy. During hospitalization, she developed livedo reticularis-like peripheral skin changes prompting evaluation for autoimmune or vasculitic etiologies. Extensive infectious and autoimmune testing was ultimately notable for positive serum and CSF West Nile virus serologies, confirming neuroinvasive WNV infection. Despite transient neurologic improvement, her clinical course deteriorated, and she died following transition to comfort-focused care. This case highlights diffuse cerebral microhemorrhages as a potential finding in WNND, although their attribution remains uncertain. These findings may reflect underlying neurovascular inflammatory injury related to WNV or may represent coincident pathology and can mimic other small-vessel or autoimmune pathologies, complicating early diagnostic evaluation. Recognition of this expanded radiographic and clinical spectrum may aid timely diagnosis of WNND in patients with atypical presentations.
Opioid abuse is a major comorbidity of HIV, yet its direct effects on the brain remain unclear. Using iPSC-derived 3D human cerebral organoids (hCOs), we show that morphine directly upregulates HIV receptors CD4, CCR5, and CXCR4 in the absence of peripheral immune cells or a blood-brain barrier. This receptor induction drives a significant increase in HIV viral load within the CNS, revealing a brain-intrinsic mechanisms of opioid-mediated viral enhancement. These findings establish hCOs as a unique platform to investigate neuroHIV and provide critical insight into how opioids amplify CNS infection independently of peripheral factors.
This study examined behavioral, clinical, and hematologic factors associated with HIV-associated neurocognitive disorder (HAND) among people with HIV (PWH) using the International HIV Dementia Scale (IHDS) within a randomized clinical trial. This secondary analysis used data from the Hospital Visit as Opportunity for Prevention and Engagement for HIV-Infected Drug Users (HOPE) study, which enrolled 801 PWH who use substances from 11 U.S. hospitals. CD4 cell count, HIV-1 viral load, Global Severity Index (GSI), Global Assessment of Functioning (GAF), and Physical and Mental Component Scores (PCS, MCS) were assessed at baseline, 6 months, and 12 months. HAND was defined as an IHDS score ≤ 10. Multivariable linear and logistic regression models were used to identify baseline correlates of IHDS score and HAND, respectively. Linear mixed models were applied to evaluate the longitudinal changes in clinical outcomes. HAND prevalence was 76.3
Propofol is a widely employed intravenous general anesthetic that can induce neurotoxic effects on neurons. Previous research has indicated dysregulation of miR-140-3p in the hippocampal tissues of propofol-treated mice. This research was designed to investigate the function and underlying mechanism of miR-140-3p in propofol-induced neurotoxicity. To simulate propofol-induced neurotoxicity, human SH-SY5Y cells and mice were treated with propofol. Commercial kits were used to measure LDH, MDA, SOD, GSH-Px, and BDNF levels. Cells were transfected with miR-140-3p mimics, inhibitor, or BACE1 overexpression plasmids. Gene expression was assessed by RT-qPCR, cell viability by CCK-8, and apoptosis by flow cytometry. Dual-luciferase and RIP assays confirmed that miR-140-3p targets BACE1. The results confirmed that as the concentration of propofol increased, miR-140-3p levels were progressively downregulated, while BACE1 was correspondingly upregulated. Upregulation of miR-140-3p rescued propofol-treated SH-SY5Y cells from cytotoxicity, as evidenced by enhanced viability, suppressed apoptosis, and ameliorated oxidative stress. Consistently, miR-140-3p overexpression also attenuated propofol-induced neurotoxicity in vivo. Furthermore, BACE1 was confirmed to be a direct target of miR-140-3p through experimental validation, and this post-transcriptional repression was shown to mediate the observed neuroprotection. miR-140-3p attenuates propofol-induced neurotoxicity via BACE1 in vitro and in vivo, providing new insights and a potential biomarker for managing propofol-associated neurotoxicity.
With over half of people with HIV (PWH) in the U.S. entering older adulthood, identifying markers to distinguish Alzheimer’s disease (AD) and its precursor, amnestic mild cognitive impairment (aMCI), from other forms of neurocognitive impairment among PWH is urgent. We examined how HIV and aMCI status relate to AD CSF biomarkers in adult PWH and people without HIV (PWoH) characterized for aMCI. We included 80 PWH from the National NeuroHIV Tissue Consortium and 80 PWoH from the Wisconsin Registry for Alzheimer’s Prevention. Binary logistic regressions of AD-related CSF biomarker positivity (Aβ42, Aβ42/Aβ40, t-tau, p-tau181, Aβ42/t-tau) were conducted with HIV serostatus, aMCI status, HIV x aMCI interaction, and demographic covariates. Among PWH, we examined how HIV-disease characteristics relate to AD biomarker positivity. No HIV x aMCI interactions were detected. Regardless of aMCI status, having HIV was associated with higher odds of CSF Aβ42 (OR = 7.97) and Aβ42/Aβ40 (OR = 6.06) positivity, suggesting increased cerebral Aβ plaque burden. Regardless of HIV serostatus, having aMCI was associated with higher odds of CSF p-tau181 positivity (OR = 3.64). Neither HIV nor aMCI status related to Aβ42/t-tau positivity. No HIV-disease characteristics related to AD biomarker positivity. Higher CSF Aβ positivity in PWH versus PWoH, regardless of aMCI status, suggests that HIV disease promotes amyloidosis; however, whether positive CSF biomarkers in PWH raises risk for future cognitive impairment and AD remains to be explored longitudinally. Like PWoH, elevated CSF p-tau181 among PWH may indicate increased risk for AD-related memory impairment.
Despite effective antiretroviral therapy (ART) in suppressing HIV replication and reducing viral loads, latent reservoirs within the central nervous system (CNS) may contribute to persistent immune dysfunction, inflammation, and neurocognitive impairment in people living with HIV. Extracellular vesicles (EVs) isolated from serum and cerebrospinal fluid have been reported to contain HIV-1 RNAs, with their abundance associated with neurocognitive outcomes in ART-treated individuals. However, the mechanistic contribution of HIV-associated EVs in CNS pathology remains incompletely understood. In this study, we characterized EVs derived from latently HIV-1-infected T cells and microglial cells and identified HIV RNAs, including transactivation response element (TAR) RNA, Nef, and Tat RNA, within these particles. These EVs disrupted the integrity of a triple-cell blood–brain barrier (BBB) model by inducing apoptosis in BBB-associated cells. HIV-associated EVs were also able to traverse the BBB and promote apoptosis in cultured neuronal cells. In cerebral organoids derived from human induced pluripotent stem cells, these EVs induce production of pro-inflammatory cytokines, including IL-1β and TNF-α. Single-cell RNA sequencing of cerebral organoids exposed to microglial cell-derived EVs revealed upregulation of genes involved in double-stranded RNA signaling, apoptosis, inflammation, and microglial activation in response to HIV-associated EVs. Additionally, these EVs induced increased expression and phosphorylation of protein kinase R (PKR) in cerebral organoids. Plasma-derived EVs containing HIV RNA from individuals with HIV, but not control EVs from uninfected donors, induced apoptosis in both cerebral organoids and neuronal cells. These findings suggest that HIV-associated EVs may contribute to neuroinflammatory processes and cellular injury in CNS models, potentially informing mechanisms underlying HIV-related neurocognitive impairment that persist despite ART.
Numerous pathogen infections in the human central nervous system can initiate potentially fatal neurological inflammation, including encephalitis, meningitis, meningoencephalitis and myelitis. Several bacterial, viral, fungal and protozoan parasite pathogens can initiate such neurological disorders. Pathogens of the central nervous system can achieve this either by their original active infections, or by reactivated infections after a period of latency. The original infections can be transmitted between humans by aerosols, respiratory droplets, ingestion, or physical contact. Some pathogens can also be transmitted from mother-to-child. Or the pathogens can be transmitted to humans by non-human vectors, by means of bites from mosquitoes, ticks, flies, or other insects, or by bites, contact, ingestion or proximity involving various wild or domestic animals. In summary, several viral pathogens either in their original active state or during one of their reactivations after latency, are capable of infecting the human central nervous system and initiating the most severe and dangerous types of encephalitis, meningitis, meningoencephalitis and myelitis.
Currently, human immunodeficiency virus-1 (HIV-1) spreads around the globe and half of HIV-1-positive individuals suffer from HIV-associated neurocognitive disorder (HAND). HIV-1 infection of astrocytes leads to neuroinflammation and neuronal injury. However, the underlying molecular mechanisms of HIV-1 negative factor (Nef)-mediated astrocytic dysfunction, remain largely unclear. In the present study, our data showed that astrocytic Nef expression facilitated astrocytes proliferation, pro-inflammatory cytokines production and A1-like astrocytes polarization. Mechanistically, Nef-activated NF-κB p65 directly bound to the promoter regions of the proliferative marker (CyclinD1), the inflammatory genes (Il-6, Ccl2, Ccl5 and Cxcl10) and the A1-specific marker (C3), and upregulated these genes expression at transcriptional levels. Conversely, NF-κB signaling inhibitor BAY11-7082 (2 μM) or RNA interference targeting of NF-κB p65 markedly mitigated astrocytes-mediated Nef neurotoxicity. Moreover, Nef-transduced astrocytes-derived conditioned media induced large amount of apoptotic HT-22 and SH-SY5Y neural cells, which was remarkably reversed in response to NF-κB inhibition. Finally, in animal models, we determined that knockdown of NF-κB p65 effectively ameliorated Nef‑induced neuroinflammation, A1-like astrocytes polarization and neuronal death. Taken together, our data suggest that Nef induces astrocytes proliferation, inflammatory response, A1-like astrocytes polarization and neuronal death in a NF-κB-dependent manner. Our findings propose that NF-κB signaling might be a desirable therapeutic target for relief of astrocytes-mediated Nef neurotoxicity.
Despite suppression of viral replication by antiretroviral therapy (cART) HIV-associated neurocognitive disorders (HAND) may persist. This involves chronic inflammation with activation of the monocyte-macrophage-microglia axis. We examined CXCL13, a chemokine released by these cells, as a possible marker for HAND treatment response. We longitudinally analyzed cerebrospinal fluid (CSF) from before and during newly initiated cART of people living with HIV (PLWH) with HIV-associated dementia (HAD). CXCL13CSF was determined by ELISA. We studied the correlation of CXCL13CSF with HAD as measured by the Memorial Sloan Kettering score (MSK-score) and with CSF and blood parameters. Twelve treatment-naïve patients with HAD were included. Prior to cART the correlation of CXCL13CSF (τ_b = 0.575, p = 0.051) with MSK-score narrowly missed significance. At an average of 2,9 months after start of cART, CXCL13CSF strongly correlated with MSK-score (τ_b = 0.746, p = 0.005). Also, the magnitude of the longitudinal change of CXCL-13CSF correlated with the change of MSK-score (τ_b = 0.460, p = 0.048). No correlation was found between MSK-score and CSF white blood cell count (WBCCSF) as well as HIV-RNA (plasma, CSF). CXCL13CSF showed a significant correlation with HAD but not with WBCCSF and HIV-RNA. As CXCL13 in the CNS is secreted by macrophages and microglia our results suggest a significant role of the monocyte-macrophage-microglia axis as a line of immunological defense relatively independent of viral replication. If supported by further studies CXCL13 might serve as CSF biomarker in HIV patients with HAD.
Blood biomarkers would be the ideal tool in routine practice in early identifying People With HIV (PWH) with low cognitive performance (LNP). We aimed to assess the diagnostic performance of neurodegeneration and brain injury biomarkers in cerebrospinal fluid (CSF) and serum to detect global and domain-specific cognitive performance in PWH. Retrospective cross-sectional study. Serum and CSF Tau, NFL, GFAP, UCH-L1, BDNF, AB40 and AB42, and CSF SNAP25 concentrations were measured by Single Molecule Assay (SiMoA) in treated PWH without neurological confounders. Global Deficit Score (GDS) was calculated assessing 6 cognitive domains; LNP defined as GDS ≥ 0.5. Correlations, AUROC, and diagnostic accuracy metrics were used to study the relationships between GDS, domain impairment, and biomarkers. 74 adult PWH on suppressive antiretroviral therapy were included (53
Background PML from JC polyomavirus (JCV) reactivation is a major safety threat in multiple sclerosis, especially with natalizumab. However, it remains unknown which microRNA (miRNA) signals consistently indicate PML risk and JCV reactivation across studies. Aim Here we synthesize and critically appraise evidence for miRNAs as biomarkers of PML risk and JCV activity in MS. Methods A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant systematic review of PubMed, Embase, Scopus, and Web of Science to April 1, 2025 identified studies assessing miRNAs and PML/JCV in MS. Two reviewers independently screened records and extracted data; findings were summarized qualitatively due to heterogeneity. Results Of 529 records screened, 7 studies met inclusion (n = 307 MS patients). The most consistent, previously elusive signals involved JCV miRNA-J1-5p and human miR-126, whose dysregulation recurred across independent cohorts and aligned with PML diagnosis or laboratory evidence of JCV reactivation. Across the included literature, miRNA profiling revealed add-on value to current JCV antibody and polymerase chain reaction (PCR)–based risk stratification, supporting its use as an adjunct rather than a replacement. Reporting was heterogeneous and effect estimates were seldom standardized, precluding meta-analysis. Conclusions Current evidence demonstrates a plausible, previously unresolved miRNA signature for PML risk and JCV activity, centered on JCV miRNA-J1-5p and miR-126. This synthesis opens the door to earlier, mechanism-informed surveillance and enables rational design of prospective validation studies for clinical translation.
Neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease, Amyotrophic Lateral Sclerosis (ALS), and Multiple Sclerosis (MS) pose a global health challenge due to their progressive course and lack of curative therapies. These conditions lead to severe neurological decline, significantly impacting patient independence and quality of life, and ultimately result in lethal outcome. Emerging evidence suggests that viral infections contribute to the onset and progression of these neurological diseases, Leblanc and Vorberg (PLoS Pathog 18:e1010670, 2022), either by directly inducing neurological symptoms or by triggering immune responses resulting in neuropathology. Nevertheless, systematic studies of the direct interplay between viral and host proteins in neurodegeneration remain scarce. A key aspect of viral pathogenesis is direct interaction between viral and host proteins (protein–protein interactions, PPIs), which are essential for viral replication and can disrupt or redirect host cell function Kim et al. (Nat Biotechnol, 2022); Zhou et al. (Res Sq, 2022), potentially contributing to the development of diseases traditionally considered non-communicable. Understanding these molecular mechanisms is crucial for advancing diagnostic and therapeutic strategies in neurodegenerative conditions, particularly ALS and MS. To enable systematic studies of these interactions, we introduce NeuroViOme as ORFeome resource encompassing nearly all protein-coding sequences from nine viruses selected based on their prevalence, neurotropism, and mechanistic or epidemiological links to neurodegenerative processes. NeuroViOme includes ORFs from Enteroviruses (EV-A71, EV-D68, CVB3, Echovirus E30), Herpesviruses (HSV-1, EBV, HHV3/Varicella Zoster), the endogenous retrovirus HERV-K, and Polyomavirus JCPyV. To our knowledge, this represents the most comprehensive viral ORF set assembled for neurodegeneration research to date. The collection builds the foundation for interactome mapping and functional genomics analyses and provides a valuable basis for systematic studies of viral perturbations of host pathways.
A 62-year-old man developed HSV-1 encephalitis with involvement of the left fronto-temporal lobes and caudate nucleus, improving under acyclovir. One month later, he developed mild word-finding difficulty. MRI showed the emergence of ring-enhancing nodular lesions with surrounding edema, confined to previously affected areas. Extensive repeat investigations revealed no alternative diagnosis. The patient recovered and remained clinically stable during follow-up. MRI over three years showed slow regression of the nodular lesions. A lumbar puncture at 3.5 years confirmed ongoing intrathecal immunoglobulin synthesis, with HSV-1-specific intrathecal synthesis. This case illustrates a rare post-herpetic granulomatous evolution, previously reported in only a few adults.
Usutu virus (USUV) is a zoonotic arbovirus causing systemic and neuroinvasive diseases in birds and flu-like or sporadic neuroinvasive disease in humans. USUV-associated encephalitis is morphologically well-characterized in birds, while the mechanisms of cell-damage in spontaneously infected birds remain poorly understood. For the closely related West Nile virus, apoptosis significantly contributes to the pathogenesis of othoflavivirus-induced neuropathology. This study investigates the involvement of apoptosis in USUV-associated encephalitis in Eurasian blackbirds (Turdus merula). To determine the apoptosis involvement, immunohistochemistry for cleaved-caspase-3 (CC3), TUNEL-assay, and RT-qPCR to compare mRNA expression levels of caspase 8 (extrinsic pathway) and caspase 9 (intrinsic pathway) were performed on brains of USUV-infected (n = 26) and USUV-uninfected (n = 16) blackbirds, as well as Africa 3 and Europe 3 USUV-lineages. The results showed a higher CC3 expression in USUV-infected (m = 231,96 ± 117,033) compared to uninfected blackbirds (m = 22,00 ± 13,31) (p < 0.001). Similarly, higher TUNEL-positive cell counts were detected in USUV-infected (m = 197,00 ± 83,56) compared to uninfected blackbirds (m = 19,00 ± 16,08) (p < 0.01). No significant differences were detected comparing Africa 3 and Europe 3 lineages. Additionally, both caspases were upregulated in USUV-infected blackbirds. Caspase 8 was in average 4,37 ± 0,89 (CI α = 0,05) times higher in USUV-infected blackbirds (p < 0.0001), while caspase 9 expression was in average 1,82 ± 0,89 (CI α = 0,05) times higher in USUV-infected blackbirds (p < 0.01). Although both apoptotic pathways are involved, the extrinsic pathway is notably more active in USUV-infected blackbirds, highlighting its role in USUV-associated brain damage.
The mechanisms by which microglia respond to viral central nervous system (CNS) pathogens are now becoming apparent with the demonstration that they express an array of pattern recognition receptors that include cytosolic sensors for exogenous nucleic acids. We have previously shown that microglia express Z-DNA binding protein 1 (ZBP1) and found that this sensor contributes to their inflammatory responses to the clinically relevant DNA virus, herpes simplex virus-1 (HSV-1). More recently, we showed that ZBP1 serves as a restriction factor for HSV-1 in murine astrocytes and is associated with the induction of both necroptotic and apoptotic cell death pathways in these cells. Here, we demonstrate that this cytosolic DNA sensor similarly functions as a HSV-1 restriction factor in primary murine microglia. However, unlike astrocytes, we have determined that a neuroinvasive clinically-derived HSV-1 isolate induces necroptosis, but not apoptosis, in these myeloid cells in a ZBP1-dependent as well as a ZBP1-independent manner. Interestingly, we found that a laboratory adapted HSV-1 strain elicits microglial apoptosis in a ZBP-1-independent manner, in addition to both ZBP1-dependent and independent necroptosis, indicating that viral strain-specific differences may exist. However, it remains to be seen whether ZBP1-mediated cell death in microglia contributes significantly to host protection or, rather, exacerbates DNA virus-associated CNS pathology in mice.
