HHV-6 Foundation

Human herpesvirus-6B (HHV-6B) reactivation has been associated with non-relapse mortality (NRM) and overall mortality (OM) following allogeneic hematopoietic stem cell transplant (HCT). We performed a systematic review and meta-analysis to better quantify the association. Studies were included if they systematically tested a cohort of HCT recipients for HHV-6 infection or reactivation and described mortality for patients with and without HHV-6B. Random effects models were used to assess the pooled effect of HHV-6B positivity on each outcome of interest. Bayesian aggregation was additionally performed if models included 10 or fewer studies. Eight studies were included in the NRM analysis, which demonstrated a significant association between HHV-6 detection and NRM (pooled effect: 1.84; 95% CI: 1.29–2.62) without significant heterogeneity (I2 = 0.0%, p = 0.55). A Bayesian aggregation of the raw data used to construct the NRM random effects model supported these findings (95% credible interval: 0.15–1.13). Twenty-five studies were included in OM analysis, which showed a significant positive association (pooled effect: 1.37; 95% CI: 1.07–1.76), though considerable heterogeneity was observed (I2 = 36.7%, p < 0.05). HHV-6 detection is associated with NRM and OM following HCT. Randomized trials are warranted to evaluate if preventing or treating HHV-6B reactivation improves outcomes.

Early-life infections and associated neuroinflammation is incriminated in the pathogenesis of various mood disorders. Infection with human roseoloviruses, HHV-6A and HHV-6B, allows viral latency in the central nervous system and other tissues, which can later be activated causing cognitive and behavioral disturbances. Hence, this study was designed to evaluate possible association of HHV-6A and HHV-6B activation with three different groups of psychiatric patients. DNA qPCR, immunofluorescence and FISH studies were carried out in post-mortem posterior cerebellum from 50 cases each of bipolar disorder (BPD), schizophrenia, 15 major depressive disorder (MDD) and 50 appropriate control samples obtained from two well-known brain collections (Stanley Medical Research Institute). HHV-6A and HHV-6B late proteins (indicating active infection) and viral DNA were detected more frequently (p < 0.001 for each virus) in human cerebellum in MDD and BPD relative to controls. These roseolovirus proteins and DNA were found less frequently in schizophrenia cases. Active HHV-6A and HHV-6B infection in cerebellar Purkinje cells were detected frequently in BPD and MDD cases. Furthermore, we found a significant association of HHV-6A infection with reduced Purkinje cell size, suggesting virus-mediated abnormal Purkinje cell function in these disorders. Finally, gene expression analysis of cerebellar tissue revealed changes in pathways reflecting an inflammatory response possibly to HHV-6A infection. Our results provide molecular evidence to support a role for active HHV-6A and HHV-6B infection in BPD and MDD.

Abstract Quantitative PCR is the diagnostic pillar for clinical virology testing, and reference materials are necessary for accurate, comparable quantitation between clinical laboratories. Accurate quantitation of HHV-6 is important for detection of viral reactivation and inherited chromosomally integrated HHV-6 in immunocompromised patients. Reference materials in clinical virology commonly consist of laboratory-adapted viral strains that may be affected by the culture process. We performed next-generation sequencing to make relative copy number measurements at single nucleotide resolution of eight candidate HHV-6A and seven HHV-6B reference strains and DNA materials from the HHV-6 Foundation and Advanced Biotechnologies. 11 of 17 (65%) HHV6 candidate reference materials showed multiple copies of the origin of replication upstream of the U41 gene by next-generation sequencing. These large tandem repeats arose independently in culture-adapted HHV-6A and HHV-6B strains, measuring 1254 bp and 983 bp, respectively. Copy number measured between 4-10X copies relative to the rest of the genome. We also report the first interspecies recombinant HHV-6 strain with a HHV-6A GS backbone and &gt;5.5kb region from HHV-6B Z29 from U41-U43 that covered the origin tandem repeat. Specific HHV-6A reference strains demonstrated duplication of regions at UL1/UL2, U87, and U89, as well as deletion in the U12-U24 region and U94/95 genes. HHV-6 strains derived from cord blood mononuclear cells from different labs on different continents revealed no copy number differences throughout the viral genome. These data indicate large origin tandem duplications are an adaptation of both HHV-6A and HHV-6B in culture and show interspecies recombination is possible within theBetaherpesvirinae.ImportanceAnything in science that needs to be quantitated requires a standard unit of measurement. This includes viruses, for which quantitation increasingly determines definitions of pathology and guidelines for treatment. However, the act of making standard or reference material in virology can alter its very usefulness through genomic duplications, insertions, and rearrangements. We used deep sequencing to examine candidate reference strains for HHV-6, a ubiquitous human virus that can reactivate in the immunocompromised population and is integrated into the human genome in every cell of the body for 1% of people worldwide. We found large tandem repeats in the origin of replication for both HHV-6A and HHV-6B that are selected for in culture. We also found the first interspecies recombinant between HHV-6A and HHV-6B, a phenomenon that is well-known in alphaherpesviruses but to date has not been seen in betaherpesviruses. These data critically inform HHV-6 biology and the standard selection process.

Chronic fatigue syndrome (CFS) is one of the most controversial topics of contem‐ porary medicine and research during the past 25 years has not identified a single unifying cause of this debilitating condi‐ tion. The potential role of human herpes‐ virus 6 (HHV‐6) as one of the causative agents have been reviewed previously [1]. This article will focus on recent and unique findings on inherited HHV‐6, further sup‐ porting the concept that CFS has no single unifying cause.

In order to assess the full spectrum of human herpesvirus 6A (HHV-6A)- and HHV-6B-associated diseases, we sought to develop an HHV-6 species-specific serological assay based on immunoblot analysis. The immunodominant proteins encoded by open reading frame U11, p100 for HHV-6A (strain U1102) and 101K for HHV-6B (strain Z29), were selected to generate virus species-specific antigens. Recombinant p100 and 101K were produced in a prokaryotic expression system. The expression of these proteins was confirmed by using anti-His tag and 101K-specific monoclonal antibodies. HHV-6 species-specific antibodies were detected by immunoblotting in patient sera. Eighty-seven serum samples obtained from various subjects were utilized to determine the reliability of the method for clinical use. Ten of twelve exanthem subitum convalescent-phase sera reacted exclusively with 101K, whereas none of twelve acute-phase sera reacted with either protein. Two of three sera collected from HHV-6A-infected patients reacted with p100 and 101K. Although all five acute and convalescent-phase sera obtained from transplant recipients reacted exclusively with 101K, two of six convalescent-phase sera obtained from patients with drug-induced hypersensitivity syndrome reacted with both p100 and 101K. Of 38 sera obtained from healthy adults, 31 were positive for 101K antibody, while 4 reacted with both proteins. However, PCR analysis of peripheral blood mononuclear cells and saliva from these subjects did not detect HHV-6A DNA. In conclusion, this novel serological assay based on immunoblot analysis using recombinant HHV-6A p100 and HHV-6B 101K allowed us to discriminate between HHV-6A- and HHV-6B-specific antibodies.

SUMMARYChromosomally integrated human herpesvirus 6 (ciHHV-6) is a condition in which the complete HHV-6 genome is integrated into the host germ line genome and is vertically transmitted in a Mendelian manner. The condition is found in less than 1% of controls in the USA and UK, but has been found at a somewhat higher prevalence in transplant recipients and other patient populations in several small studies. HHV-6 levels in whole blood that exceed 5.5 log10 copies/ml are strongly suggestive of ciHHV-6. Monitoring DNA load in plasma and serum is unreliable, both for identifying and for monitoring subjects with ciHHV-6 due to cell lysis and release of cellular DNA. High HHV-6 DNA loads associated with ciHHV-6 can lead to erroneous diagnosis of active infection. Transplant recipients with ciHHV-6 may be at increased risk for bacterial infection and graft rejection. ciHHV-6 can be induced to a state of active viral replication in vitro. It is not known whether ciHHV-6 individuals are put at clinical risk by the use of drugs that have been associated with HHV-6 reactivation in vivo or in vitro. Nonetheless, we urge careful observation when use of such drugs is indicated in individuals known to have ciHHV-6. Little is known about whether individuals with ciHHV-6 develop immune tolerance for viral proteins. Further research is needed to determine the role of ciHHV-6 in disease. Copyright © 2011 John Wiley & Sons, Ltd.

1.1 Latency and reactivation of HIV-1 Since the discovery of human immunodeficiency virus type 1 (HIV-1), there has been a great deal of interest in identifying cofactors that might accelerate the stages of development associated with acquired immunodeficiency syndrome (AIDS). Many environmental agents, namely inherent factors such as ethnicity and geographical location, were first implicated as risk factors in the study of HIV infection. However, speculation that infectious diseases may act as cofactors in HIV infection began to be studied soon thereafter. These speculations led to one of the early opinions that HIV plays a correlary role in AIDS, but not a causative role (Duesberg, 1989). AIDS patients have a history of both circumstantial serological and microbial evidence of increased exposure to a number of common and opportunistic infectious agents. It is difficult to ascertain, however, whether these various coinfections contribute anything to the progressive decline of the immune system (Pedersen et al., 1990). In vivo, infection with HIV-1 is followed by a long disease-free period, during which a low number of CD4+ mononuclear leukocytes (CCR5 coreceptor positive monocytes and CXCR4 coreceptor positive lymphocytes) containing transcriptionally silent integrated provirus can be found. HIV-1 replication can be demonstrated in only a small population of T cells without inducing clinical manifestations. This state of latency is partly due to low transcriptional activity of the integrated provirus in resting cells. Activation of CD4+ cells by antigens, mitogens (Tobiume et al., 1998) or superinfection by other viruses interacting with HIV-1 via viral and/or cellular transacting factors may terminate HIV-1 latency, leading to a productive HIV-1 infection. Transactivation of the HIV-1 long terminal repeat (LTR) in turn will induce gene expression, including the synthesis of the HIV-1 transactivator protein (TAT) (Arya et al., 1985). TAT will then independently amplify HIV-1 gene expression, ultimately leading to a high level of virus replication and death of infected cells. Onset and progression of AIDS correlates with augmented production of infectious virions parallel to a

Journal of Medical VirologyVolume 82, Issue 9 p. 1560-1568 Research Article Review, part 1: Human herpesvirus-6-basic biology, diagnostic testing, and antiviral efficacy Louis Flamand, Louis Flamand Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Laval University, Québec, CanadaSearch for more papers by this authorAnthony L. Komaroff, Anthony L. Komaroff Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, MassachusettsSearch for more papers by this authorJesse H. Arbuckle, Jesse H. Arbuckle Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FloridaSearch for more papers by this authorPeter G. Medveczky, Peter G. Medveczky Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FloridaSearch for more papers by this authorDharam V. Ablashi, Corresponding Author Dharam V. Ablashi dharam_ablashi@hhv-6foundation.org HHV-6 Foundation, Santa Barbara, California277 San Ysidro Road, Santa Barbara, CA 93108.===Search for more papers by this author Louis Flamand, Louis Flamand Department of Microbiology, Infectious Diseases and Immunology, Faculty of Medicine, Laval University, Québec, CanadaSearch for more papers by this authorAnthony L. Komaroff, Anthony L. Komaroff Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, MassachusettsSearch for more papers by this authorJesse H. Arbuckle, Jesse H. Arbuckle Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FloridaSearch for more papers by this authorPeter G. Medveczky, Peter G. Medveczky Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FloridaSearch for more papers by this authorDharam V. Ablashi, Corresponding Author Dharam V. Ablashi dharam_ablashi@hhv-6foundation.org HHV-6 Foundation, Santa Barbara, California277 San Ysidro Road, Santa Barbara, CA 93108.===Search for more papers by this author First published: 15 July 2010 https://doi.org/10.1002/jmv.21839Citations: 46Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume82, Issue9September 2010Pages 1560-1568 RelatedInformation