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EBV and HHV-6B but no CMV found in astrocytomas by digital droplet PCR

In All, Cancer, CNS Disease, Latest Scientific News by Kristin Loomis

A group from the National Institute of Neurological Disorders and Stroke, NIH, has reported finding Epstein-Barr Virus (EBV) and HHV-6 but no cytomegalovirus (CMV) in astrocytomas, a brain tumor comprising approximately one quarter of all gliomas diagnosed. The group used digital droplet PCR (ddPCR), a technique that is highly precise but less sensitive than nested PCR and immunohistochemistry, techniques that have been used in previous studies.

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Genome editing to clear latent herpesvirus infection

In All, Genes & Proteins, Treatments - Antiviral by Kristin Loomis

A group from the University Medical Center in the Netherlands has shown that new gene editing technology can be used to impair viral replication and clear latent herpesvirus infections. The group used a CRISPR-Cas system to target viral genetic elements that completely eliminated CMV and HSV1 replication. They were also able to clear latent EBV from transformed human tumor cells.

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HHV-6A infection of the uterus linked to infertility

In All, Endocrine Conditions, Host Cell Interaction, Infertility & Miscarriage by Kristin Loomis

A new study reported that HHV-6A infects the lining of the uterus in 43% of women with unexplained infertility but cannot be found in uterine lining of fertile women.  Furthermore, the cytokine and the natural killer cell profiles were very different in patients with the infection. HHV-6A was found only in uterine endothelial cells, and not in the blood.

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HHV-6, EBV and CMV found in GI tract cancers

In All, Liver Disease, Uncategorized by Kristin Loomis

A group from Washington University used a bioinformatics system called VirusScan to analyze RNA-Seq data sets from 6,813 human tumors compared to those of adjacent normal tissue. Tumor samples representing 23 different forms of cancer were analyzed. HHV-6, EBV and CMV were found at significantly high levels in GI tract cancer tissue.

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Surprise finding : HHV-6 telomeric repeats are crucial for HHV-6 integration

In All, ciHHV-6, Latest Scientific News, Molecular Biology by Kristin Loomis

When the research team led by Benedikt Kaufer attempted to shed light on the mechanism behind HHV-6 integration, they were suprised to find telomeric repeats were critical to the integration process. Since the U94 gene shares homology and biological properties with the adenovirus Rep68 gene responsible for viral integration into human chromosomes, U94 was considered the most likely candidate to mediate HHV-6 integration.

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CXCL11 and CCL2 are specific to HHV-6B in febrile infants

In All, Alzheimer's Disease, Multiple Sclerosis by Kristin Loomis

Japanese investigators from Kobe University identified CXC11 as a chemokine uniquely expressed in primary HHV-6B infections. They also confirmed a previous finding that cytokine CCL2 (MCP-1) plays a role in HHV-6B primary infections. Both CXCL11 and CCL2 are expressed in several neuroinflammatory conditions including epilepsy, Alzheimer’s disease and traumatic brain injury.

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The crystal structure of HHV-6B U14 defined

In All, Genes & Proteins, Molecular Biology by Kristin Loomis

A group led by Yasuko Mori in Japan has analyzed the crystal structure of HHV-6B U14, an important accomplishment for the understanding of HHV-6. Human herpesvirus 6B encodes numerous tegument proteins that make up the viral matrix. One of these tegument proteins is U14. In addition to being necessary for viral propagation, it is able to regulate host cell responses by interacting with host factors such as tumor suppressor p53.

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Does CD134 upregulation explain why HHV-6 reactivates preferentially in DRESS/ DIHS?

In All, Drug Hypersensitivity, Latest Scientific News, Skin Conditions, Transplant Complications by Kristin Loomis

It has long been a mystery why HHV-6 is preferentially reactivated in drug reaction with eosinophilia and systemic symptoms (DRESS), also known as drug induced hypersensitivity syndrome (DIHS). HHV-6 reactivation occurs in over 60% of severe cases and is part of the definition of DIHS in Japan. Investigators in Japan suspect that the explanation may lie with the CD134 receptor on activated CD4 cells.

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GAD antibodies & HHV-6 limbic encephalitis – a case of molecular mimicry?

In All, Autoimmune Disease, CNS Disease, CNS Dysfunction, Encephalitis & Encephalopathy, Epilepsy and Seizures, Host Cell Interaction by Kristin Loomis

A fifth case of limbic encephalitis associated with GAD antibodies and HHV-6 infection has been reported, this time in an immunocompetent woman with chromosomally integrated HHV-6, epilepsy, and psychosis. The patient’s condition improved (with a drop in GAD antibody titers and stabilization of psychotic symptoms) in response to three weeks of antiviral therapy but relapsed when antiviral therapy was withdrawn.

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HHV-6 & 7 found in spinal fluid of immunocompetent children suspected of CNS infection

In All, CNS Disease, CNS Dysfunction, Latest Scientific News by Kristin Loomis

An Italian study on immunocompetent children with suspected CNS infections found HHV-6 and HHV-7 DNA in 4.2% and 4.8% of 304 cerebrospinal fluid (CSF) samples, respectively. Although once considered rare in the immunocompetent, recent studies with more sensitive methods have found HHV-6 in the CSF of 4-17% of immunocompetent children with seizures or suspected CNS infections.

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Drug-induced liver injury and HHV-6 reactivation without rash or fever

In All, Liver Disease, Transplant Complications by Kristin Loomis

Another case of drug induced liver injury accompanied by HHV-6 reactivation has been reported in Japan, the second such case without exanthema to be described. An earlier case was reported last year (Fujita 2015). The authors suggest that drug-induced liver injury cases be investigated for HHV-6 reactivation when liver dysfunction begins several weeks after the initiation of a new drug typically associated with hypersensitivity syndromes.