Both infectious and UV-inactivated HHV-6A activate endogenous retrovirus envelope protein – but so does selective stimulation of HHV-6A’s CD46 receptor. This “cross-talk” between HHV-6A and endogenous retrovirus appears to play an important role in the pathogenesis of inflammatory diseases.
The HHV-6 latency gene U94 has been found to block angiogenesis, but the mechanisms behind this phenomenon have been unclear. A team lead by Roberta Rizzo and Elisabetta Caselli in Italy shed light on this process, opening the door to new potential molecular targets to pursue in treating diseases marked by improper vascularization.
A group led by Mara Cirone in Italy found that HHV-6B blocks autophagy in HSB-2 cells. Both HSV-1 and CMV have proteins that block autophagy, and HHV-6B carries genes that are homologues of those encoding for CMV’s anti-autophagy protein. Her next step is to study the impact of both HHV-6A and HHV-6B on autophagy in neuronal cells.
The NEJM rarely covers HHV-6, but did an excellent case history of this patient with HHV-6 reactivation in conjunction with DRESS. The patient was not treated with an antiviral in spite of a plasma HHV-6 DNA load of 112,836, extensive lymphadenopathy, rash and abnormal liver function tests. What did NEJM get wrong? They stated ciHHV6 could be ruled out because a) the viral load was only log 5 on a plasma DNA test and b) the viral load dropped to less than 500 copies/ml. The plasma viral load in a ciHHV-6 patient can fall below 500 copies/ml if the blood is centrifuged within a few hours. On the other hand, ciHHV-6 samples shipped overnight and centrifuged the next day, are …
A genomic analysis of samples from 141,431 Chinese women found a highly significant association between ciHHV-6 and a variant in the MLCI-MOV10L region. The MLC1 gene is involved in myeloid cell differentiation and the MOV10L1 gene may allow for more efficient integration during spermatogenesis.
In a study led by Manfred Marschall German investigators analyzed the potency of novel pyrrolopyridine-class compounds and found one that is highly active against CMV and HHV-6A. It works at an early stage of viral protein production, and differs from ganciclovir in mechanism.
HHV-6 was found more frequently in the Purkinje cells of bipolar and major depressive disorder patients compared to controls. Furthermore HHV-6A was associated with a reduced Purkinje cell size. HHV-6 was not found, however in patients with schizophrenia.
German investigators suggest that silencing of HHV-6A by the ND10 complex may explain why HHV-6A is more likely than other herpesviruses to establish a quiescent infection.
German investigators have identified a marker for what they believe is the earliest stage of viral reactivation, or “transactivation” marked by transcription of several viral small non-coding RNAs in the absence of detectable viral replication. The group believes that these viral small RNAs could be developed as biomarkers.
After years of very little interest by the scientific community, there has suddenly been a lot of interest in HHV-6A, which along with HHV-7, appears to be central to the progression of Alzheimer’s disease.
Using a novel serological assay that can differentiate HHV-6A from HHV-6B, investigators found HHV-6A immediate early antibodies to be associated with an increased risk of non-Hodgkin lymphoma.
German investigators conducted a broad scale analysis of CD8 T cell responses to HHV-6B, identifying novel epitopes with potential for immunotherapy or vaccines. The strongest responses were directed against an epitope from IE-2.
A gigantic sequencing effort by investigators at University of Washington has provided a wealth of new information about the HHV-6B genome, including important flaws of the reference strains currently in use.
A broadscale investigation of the ovarian cancer oncobiome using a microarray system PathoChip found HHV-6A sequences at or near genes associated with tumorigenesis in ovarian cancer tissue samples.
Italian investigators showed that HHV-6A and -6B infection of natural killer cells have a remarkable effect on the expression of miRNAs and transcription factors, which in turn control natural killer cell development, maturation and function.