Category: Viruses

Tissue specific signature of HHV-6 infection in ME/CFS

Abstract:

First exposure to various human herpesviruses (HHVs) including HHV-6, HCMV and EBV does not cause a life-threatening disease. In fact, most individuals are frequently unaware of their first exposure to such pathogens. These herpesviruses acquire lifelong latency in the human body where they show minimal genomic activity required for their survival. We hypothesized that it is not the latency itself but a timely, regionally restricted viral reactivation in a sub-set of host cells that plays a key role in disease development.

HHV-6 (HHV-6A and HHV-6B) and HHV-7 are unique HHVs that acquire latency by integration of the viral genome into sub-telomeric region of human chromosomes. HHV-6 reactivation has been linked to Alzheimer’s Disease, Chronic Fatigue Syndrome, and many other diseases. However, lack of viral activity in commonly tested biological materials including blood or serum strongly suggests tissue specific localization of active HHV-6 genome.

Here in this paper, we attempted to analyze active HHV-6 transcripts in postmortem tissue biopsies from a small cohort of ME/CFS patients and matched controls by fluorescence in situ hybridization using a probe against HHV-6 microRNA (miRNA), miR-aU14. Our results show abundant viral miRNA in various regions of the human brain and associated neuronal tissues including the spinal cord that is only detected in ME/CFS patients and not in controls.

Our findings provide evidence of tissue-specific active HHV-6 and EBV infection in ME/CFS, which along with recent work demonstrating a possible relationship between herpesvirus infection and ME/CFS, provide grounds for renewed discussion on the role of herpesviruses in ME/CFS.

Source: Prusty, Bhupesh K.; Kasimir, Francesca; Toomey, Danny; Liu, Zheng; Agnes Kaiping and Ariza, Maria Eugenia. Tissue specific signature of HHV-6 infection in ME/CFS. Front. Mol. Biosci. Sec. Molecular Diagnostics and Therapeutics. doi: 10.3389/fmolb.2022.1044964 https://www.frontiersin.org/articles/10.3389/fmolb.2022.1044964/abstract

HERV-W ENV antigenemia and correlation of increased anti-SARS-CoV-2 immunoglobulin levels with post-COVID-19 symptoms

Abstract:

Due to the wide scope and persistence of COVID-19´s pandemic, post-COVID-19 condition represents a post-viral syndrome of unprecedented dimensions. SARS-CoV-2, in line with other infectious agents, has the capacity to activate dormant human endogenous retroviral sequences ancestrally integrated in human genomes (HERVs). This activation was shown to relate to aggravated COVID-19 patient´s symptom severity.

Despite our limited understanding of how HERVs are turned off upon infection clearance, or how HERVs mediate long-term effects when their transcription remains aberrantly on, the participation of these elements in neurologic disease, such as multiple sclerosis, is already settling the basis for effective therapeutic solutions. These observations support an urgent need to identify the mechanisms that lead to HERV expression with SARS-CoV-2 infection, on the one hand, and to answer whether persistent HERV expression exists in post-COVID-19 condition, on the other.

The present study shows, for the first time, that the HERV-W ENV protein can still be actively expressed long after SARS-CoV-2 infection is resolved in post-COVID-19 condition patients. Moreover, increased anti-SARS-CoV-2 immunoglobulins in post-COVID-19 condition, particularly high anti-SARS-CoV-2 immunoglobulin levels of the E isotype (IgE), seem to strongly correlate with deteriorated patient physical function (r=-0.8057, p<0.01).

These results indicate that HERV-W ENV antigenemia and anti-SARS-CoV-2 IgE serology should be further studied to better characterize post-COVID-19 condition pathogenic drivers potentially differing in subsets of patients with various symptoms. They also point out that such biomarkers may serve to design therapeutic options for precision medicine in post-COVID-19 condition.

Source: Giménez-Orenga K, Pierquin J, Brunel J, Charvet B, Martín-Martínez E, Perron H, Oltra E. HERV-W ENV antigenemia and correlation of increased anti-SARS-CoV-2 immunoglobulin levels with post-COVID-19 symptoms. Front Immunol. 2022 Oct 27;13:1020064. doi: 10.3389/fimmu.2022.1020064. PMID: 36389746; PMCID: PMC9647063.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9647063/ (Full text)

Investigating the enterovirus theory of disease etiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex, multi-system disease whose etiological basis has not been established. Over the years, several pathogenic agents have been implicated with no one pathogen being conclusively identified as responsible for induction of a large number of cases. Enteroviruses (EVs) as a cause of ME/CFS have sometimes been proposed, as they are known agents of acute respiratory and gastrointestinal infections that may persist in chronic infection sites, including the central nervous system, muscle, and heart, potentially resulting in chronic conditions that have symptom constellations like those of ME/CFS.

To gain insight into the association between EVs and ME/CFS, I conducted a comprehensive review of EV studies in ME/CFS and followed this with 1) a broad serological survey of ME/CFS antibody levels to 122 pathogenic antigens and 2) designed and conducted EV-specific targeted RNA sequencing.

A review of prior ME/CFS investigations in ME/CFS revealed a strong prevalence of chronic EV infections across ME/CFS cohorts. The broad survey of anti-pathogen antibody levels in ME/CFS cases did not implicate any one pathogen as a causative factor in ME/CFS, nor do they rule out common pathogens that frequently infect the US population. However, the results did reveal sex-based differences in steady-state humoral immunity, both within the ME/CFS cohort and when compared to trends seen in the healthy control cohort.

Furthermore, I find that our EV-specific probe set allows efficient viral detection when as few as 10 molecules are present in 1ml of blood. However, whether the technology is employed directly on patient samples or following attempts at in vitro biological amplification, EVs were undetected in both ME/CFS and healthy control samples despite all approaches that were pursued.

This work establishes a thorough understanding of the current EV-ME/CFS related literature while simultaneously providing an acutely sensitive and comprehensive approach that will be useful in the future for screening biopsy or cadaver samples from any individuals suspected of having a chronic EV infection.

Source: O’Neal, Adam James. Investigating the enterovirus theory of disease etiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Dissertation, Cornell. https://ecommons.cornell.edu/handle/1813/112023 (Full text will be made available)

Saliva antibody-fingerprint of reactivated latent viruses after mild/asymptomatic COVID-19 is unique in patients with myalgic-encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic disease considered to be triggered by viral infections in a majority of cases. Symptoms overlap largely with those of post-acute sequelae of COVID-19/long-COVID implying common pathogenetic mechanisms. SARS-CoV-2 infection is risk factor for sustained latent virus reactivation that may account for the symptoms of post-viral fatigue syndromes. The aim of this study was first to investigate whether patients with ME/CFS and healthy donors (HDs) differed in their antibody response to mild/asymptomatic SARS-CoV-2 infection. Secondly, to analyze whether COVID-19 imposes latent virus reactivation in the cohorts.

Methods: Anti-SARS-CoV-2 antibodies were analyzed in plasma and saliva from non-vaccinated ME/CFS (n=95) and HDs (n=110) using soluble multiplex immunoassay. Reactivation of human herpesviruses 1-6 (HSV1, HSV2, VZV, EBV, CMV, HHV6), and human endogenous retrovirus K (HERV-K) was detected by anti-viral antibody fingerprints in saliva.

Results: At 3-6 months after mild/asymptomatic SARS-CoV-2 infection, virus-specific antibodies in saliva were substantially induced signifying a strong reactivation of latent viruses (EBV, HHV6 and HERV-K) in both cohorts. In patients with ME/CFS, antibody responses were significantly stronger, in particular EBV-encoded nuclear antigen-1 (EBNA1) IgG were elevated in patients with ME/CFS, but not in HDs. EBV-VCA IgG was also elevated at baseline prior to SARS-infection in patients compared to HDs.

Conclusion: Our results denote an altered and chronically aroused anti-viral profile against latent viruses in ME/CFS. SARS-CoV-2 infection even in its mild/asymptomatic form is a potent trigger for reactivation of latent herpesviruses (EBV, HHV6) and endogenous retroviruses (HERV-K), as detected by antibody fingerprints locally in the oral mucosa (saliva samples). This has not been shown before because the antibody elevation is not detected systemically in the circulation/plasma.

Source: Apostolou Eirini, Rizwan Muhammad, Moustardas Petros, Sjögren Per, Bertilson Bo Christer, Bragée Björn, Polo Olli, Rosén Anders. Saliva antibody-fingerprint of reactivated latent viruses after mild/asymptomatic COVID-19 is unique in patients with myalgic-encephalomyelitis/chronic fatigue syndrome. Frontiers in Immunology, Vol 13, 2022. https://www.frontiersin.org/articles/10.3389/fimmu.2022.949787/full (Full text)

Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease that is mainly diagnosed based on its clinical symptoms. Biomarkers that could facilitate the diagnosis of ME/CFS are not yet available; therefore, reliable and clinically useful disease indicators are of high importance. The aim of this work was to analyze the association between ME/CFS clinical course severity, presence of HHV-6A/B infection markers, and plasma levels of autoantibodies against adrenergic and muscarinic acetylcholine receptors.

A total of 134 patients with ME/CFS and 33 healthy controls were analyzed for the presence of HHV-6A/B using PCRs, and antibodies against beta2-adrenergic receptors (β2AdR) and muscarinic acetylcholine receptors (M3 AChR and M4 AChR) using ELISAs. HHV-6A/B U3 genomic sequence in whole-blood DNA was detected in 19/31 patients with severe ME/CFS, in 18/73 moderate ME/CFS cases, and in 7/30 mild ME/CFS cases. Severity-related differences were found among those with a virus load of more than 1,000 copies/106 PBMCs.

Although no disease severity-related differences in anti-β2AdR levels were observed in ME/CFS patients, the median concentration of these antibodies in plasma samples of ME/CFS patients was 1.4 ng/ml, while in healthy controls, it was 0.81 ng/ml, with a statistically significant increased level in those with ME/CFS (p = 0.0103). A significant difference of antibodies against M4 AChR median concentration was found between ME/CFS patients (8.15 ng/ml) and healthy controls (6.45 ng/ml) (p = 0.0250). The levels of anti-M4 plotted against disease severity did not show any difference; however, increased viral load correlates with the increase in anti-M4 level.

ME/CFS patients with high HHV-6 load have a more severe course of the disease, thus confirming that the severity of the disease depends on the viral load—the course of the disease is more severe with a higher viral load. An increase in anti-M4 AchR and anti-β2AdR levels is detected in all ME/CFS patient groups in comparison to the control group not depending on ME/CFS clinical course severity. However, the increase in HHV-6 load correlates with the increase in anti-M4 level, and the increase in anti-M4 level, in turn, is associated with the increase in anti-β2AdR level. Elevated levels of antibodies against β2AdR and M4 receptors in ME/CFS patients support their usage as clinical biomarkers in the diagnostic algorithm of ME/CFS.

Source: Gravelsina S, Vilmane A, Svirskis S, Rasa-Dzelzkaleja S, Nora-Krukle Z, Vecvagare K, Krumina A, Leineman I, Shoenfeld Y and Murovska M (2022) Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome. Front. Immunol. 13:928945. doi: 10.3389/fimmu.2022.928945 https://www.frontiersin.org/articles/10.3389/fimmu.2022.928945/full (Full text)

Tunneling nanotubes provide a route for SARS-CoV-2 spreading

Abstract:

Neurological manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection represent a major issue in long coronavirus disease. How SARS-CoV-2 gains access to the brain and how infection leads to neurological symptoms are not clear because the principal means of viral entry by endocytosis, the angiotensin-converting enzyme 2 receptor, are barely detectable in the brain.

We report that human neuronal cells, nonpermissive to infection through the endocytic pathway, can be infected when cocultured with permissive infected epithelial cells. SARS-CoV-2 induces the formation of tunneling nanotubes (TNTs) and exploits this route to spread to uninfected cells. In cellulo correlative fluorescence and cryo-electron tomography reveal that SARS-CoV-2 is associated with TNTs between permissive cells. Furthermore, multiple vesicular structures such as double-membrane vesicles, sites of viral replication, are observed inside TNTs between permissive and nonpermissive cells.

Our data highlight a previously unknown mechanism of SARS-CoV-2 spreading, likely used as a route to invade nonpermissive cells and potentiate infection in permissive cells.

Source: Pepe A, Pietropaoli S, Vos M, Barba-Spaeth G, Zurzolo C. Tunneling nanotubes provide a route for SARS-CoV-2 spreading. Sci Adv. 2022 Jul 22;8(29):eabo0171. doi: 10.1126/sciadv.abo0171. Epub 2022 Jul 20. PMID: 35857849; PMCID: PMC9299553.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9299553/ (Full text)

Predicting the efficacy of variant-modified COVID-19 vaccine boosters

Abstract:

As a result of the emergence and circulation of antigenically distinct SARS-CoV-2 variants, a number of variant-modified COVID-19 vaccines have been developed. Here we perform a meta-analysis of the available data on neutralisation titres from clinical studies comparing booster vaccination with either the current ancestral-based vaccines or variant-modified vaccines. We then use this to predict the relative efficacies of these booster vaccines under different scenarios.

Source: David S Khoury, Steffen S Docken, Kanta Subbarao, Stephen Kent, Miles Philip Davenport, Deborah Cromer. Predicting the efficacy of variant-modified COVID-19 vaccine boosters. medRxiv 2022.08.25.22279237; doi: https://doi.org/10.1101/2022.08.25.22279237 (Full article available as PDF file)

COVID-19 induces CNS cytokine expression and loss of hippocampal neurogenesis

Abstract:

Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with acute and postacute cognitive and neuropsychiatric symptoms including impaired memory, concentration, attention, sleep and affect. Mechanisms underlying these brain symptoms remain understudied.

Here we report that SARS-CoV-2-infected hamsters exhibit a lack of viral neuroinvasion despite aberrant blood-brain barrier permeability. Hamsters and patients deceased from coronavirus disease 2019 (COVID-19) also exhibit microglial activation and expression of interleukin (IL)-1β and IL-6, especially within the hippocampus and the medulla oblongata, when compared with non-COVID control hamsters and humans who died from other infections, cardiovascular disease, uraemia or trauma. In the hippocampal dentate gyrus of both COVID-19 hamsters and humans, we observed fewer neuroblasts and immature neurons.

Protracted inflammation, blood-brain barrier disruption and microglia activation may result in altered neurotransmission, neurogenesis and neuronal damage, explaining neuropsychiatric presentations of COVID-19. The involvement of the hippocampus may explain learning, memory and executive dysfunctions in COVID-19 patients.

Source: Soung AL, Vanderheiden A, Nordvig AS, Sissoko CA, Canoll P, Mariani MB, Jiang X, Bricker T, Rosoklija GB, Arango V, Underwood M, Mann JJ, Dwork AJ, Goldman JE, Boon ACM, Boldrini M, Klein RS. COVID-19 induces CNS cytokine expression and loss of hippocampal neurogenesis. Brain. 2022 Aug 25:awac270. doi: 10.1093/brain/awac270. Epub ahead of print. PMID: 36004663. https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awac270/6672950?login=false  (Full text)

SARS CoV-2 detected in neonatal stool remote from maternal COVID-19 during pregnancy

Abstract:

Background: In utero transmission of SARS coronavirus 2 (SARS-CoV-2) has not been fully investigated. We investigated whether newborns of mothers with COVID-19 during pregnancy might harbor SARS-CoV-2 in the gastrointestinal tract.

Methods: This cohort study investigated stool from 14 newborns born at 25-41 weeks admitted at delivery to our urban academic hospital whose mothers had COVID-19 during pregnancy. Eleven mothers had COVID-19 resolved more than 10 weeks before delivery. Newborn stool was evaluated for SARS-CoV-2 RNA, Spike protein, and induction of inflammatory cytokines interleukin-6 (IL-6) and interferon-γ (IFN-γ) in macrophages.

Results: Despite negative SARS CoV-2 nasal PCRs from all newborns, viral RNAs and Spike protein were detected in the stool of 11 out of 14 newborns as early as the first day of life and increased over time in 6. Stool homogenates from all 14 newborns elicited elevated inflammatory IL-6 and IFN-γ from macrophages. Most newborns were clinically well except for one death from gestational autoimmune liver disease and another who developed necrotizing enterocolitis.

Conclusions: These findings suggest in utero transmission of SARS-CoV-2 and possible persistent intestinal viral reservoirs in the newborns. Further investigation is required to understand the mechanisms and their clinical implications.

Impact: SARS-CoV-2 RNAs or Spike protein was detected in the stool of 11 out of 14 preterm newborns born to mothers with resolved COVID-19 weeks prior to delivery despite negative newborn nasal PCR swabs. These novel findings suggest risk of in utero SARS-CoV-2 transmission to the fetal intestine during gestation. The presence of SARS-CoV-2 RNAs and Spike protein in the intestines of newborns may potentially impact the development of the gut microbiome and the immune system; the long-term health impact on the preterm infants should be further investigated.

Source: Jin JC, Ananthanarayanan A, Brown JA, Rager SL, Bram Y, Sanidad KZ, Amir M, Baergen RN, Stuhlmann H, Schwartz RE, Perlman JM, Zeng MY. SARS CoV-2 detected in neonatal stool remote from maternal COVID-19 during pregnancy. Pediatr Res. 2022 Aug 19. doi: 10.1038/s41390-022-02266-7. Epub ahead of print. PMID: 35986143. https://www.nature.com/articles/s41390-022-02266-7 (Full text)

Herpesvirus and neurological manifestations in patients with severe coronavirus disease

Abstract:

Background: Certain clinical manifestations of coronavirus disease (COVID-19) mimic those associated with human herpesvirus (HHV) infection. In this study, we estimated the prevalence of herpesvirus in patients with COVID-19 and determined if coinfection is associated with poorer outcomes and neurological symptoms.

Methods: We analyzed samples of 53 patients diagnosed with COVID-19. The samples were evaluated for the presence of alphaherpesviruses, betaherpesviruses, and gammaherpesviruses, and the viral loads were quantified using quantitative polymerase chain reaction (qPCR) method.

Results: Among the patients, in 79.2% had detection at least one type of herpesvirus. HHV-6 (47.2%), cytomegalovirus (43.3%), and HHV-7 (39.6%) showed the highest detection rates. Patients with a high severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) load were more likely to show herpes simplex virus 1 detection (p = 0.037). Among patients coinfected with SARS-CoV-2 and HHVs, 26.4% showed central nervous system-associated neurological symptoms and herpetic manifestations. A statistically significant association was observed between neurological changes and HHV-6 detection (p = 0.034).

Conclusions: The findings showed a high prevalence of herpesvirus in patients with COVID-19. Furthermore, even though SARS-CoV-2 and HHV coinfection was not associated with poorer outcomes, the findings demonstrated the association between neurological symptoms and HHV-6 detection.

Source: Carneiro VCS, Alves-Leon SV, Sarmento DJS, Coelho WLDCNP, Moreira ODC, Salvio AL, Ramos CHF, Ramos Filho CHF, Marques CAB, da Costa Gonçalves JP, Leon LAA, de Paula VS. Herpesvirus and neurological manifestations in patients with severe coronavirus disease. Virol J. 2022 Jun 8;19(1):101. doi: 10.1186/s12985-022-01828-9. PMID: 35676707; PMCID: PMC9174631. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9174631/  (Full text)