Human Herpesvirus 6A (HHV-6A) and 6B (HHV-6B) are ubiquitous betaherpesviruses. Both viruses are associated with a variety of adult disorders including neurological disorder, such as multiple sclerosis and chronic fatigue syndrome. HHV-6 viruses are capable of establishing latency by integration into the telomeres of the host chromosome and are transmitted in a Mendelian manner in approximately one percent of the population. To date little is known about the immunological and neurological consequences of HHV-6 inheritance. This study focused on a unique population of individuals that inherited HHV-6 and present with chronic fatigue-like symptoms, including hypersomnia, generalized fatigue, headache, and short term and long term memory impairment. The central hypothesis of this study was that active replication of HHV-6 correlates with patient symptoms. To address this aim we first looked at the reactivation of integrated HHV-6 in vitro by inducing viral replication with epigenetic modifiers trichostatin A (TSA), valproic acid, sodium butyrate, and carbamazepine, and found TSA to be an effective method of inducing reactivation of HHV-6 from its integrated form. Additionally, a reactivated HHV-6A virus isolated from a patient with inherited HHV-6 was fully sequenced and the nucleotide and amino acid sequence was compared to that of fully sequenced HHV-6 laboratory strains, as well as the inherited virus. The reactivated virus was found to be very similar to the HHV-6A GS strain; however, there was some divergence at the right end of the viral genome and regions of the genome that do not contain herpesvirus core genes. Interestingly, the sequenced reactivated virus was found to differ from the HHV-6 virus which was inherited. Finally, HHV-6 replication was assessed by performing reverse transcriptase PCR assay for the viral glycoprotein U100 in patients receiving antiviral treatment. Results indicated that short term antiviral treatment was insufficient to abrogate viral replication, while treatment of six weeks or longer eliminated viral mRNA in patient blood samples. Furthermore, sequencing of the viral mRNA and inherited viral DNA indicate that the source of the mRNA detected in patient blood samples was an exogenously acquired HHV-6 virus, as the U100 glycoprotein sequences were not identical. Together these studies indicate that although HHV-6 can be reactivated from its integrated form, individuals in this unique population harbored an exogenous HHV-6 virus, in addition to the inherited virus; we termed this condition inherited herpesvirus syndrome. The fact that these individuals are able to acquire exogenous HHV-6 viruses suggest that there may be some level of immune tolerance or immune dysfunction; we suggest that further studies focus on uncovering the immune response to HHV-6 in individuals with an inherited form of the virus.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 130-150).

Diss. Uppsala : Uppsala universitet, 2009.

<p>UVOD: Akutna mijeloidna leukemija (AML) predstavlja heterogenu grupu oboljenja u odnosu na morfologiju, citogenetiku, molekularnu genetiku, zbog čega se deli na različite kliničke i biolo&scaron;ke entitete, sa različitim odgovorom na terapiju i ishodom lečenja. Humani EVI1 (ecotropic virus integration-1) gen ima ulogu multifunkcionalnog nuklearnog transkripcionog faktora, kako u normalnoj tako i u malignoj hematopoezi. Sve je vi&scaron;e istraživanja koja ističu negativni prognostički značaj visoke ekspresije (overexpression) EVI1 gena u AML.&nbsp; CILJEVI: Ciljevi ovog istraživanja su da se ispita klinički i prognostički značaj ekspresije gena EVI1 u AML, kao i da se utvrdi povezanost visoke ekspresije gena EVI1 sa nalazima citogenetskog ispitivanja i molekularnim markerima: FLT3 mutacijom i nukleofozmin 1 (NPM1) mutacijom. MATERIJAL I METODE: Ovim prospektivnim istraživanjem je obuhvaćena grupa od 38 odraslih novodijagnostikovanih bolesnika sa de novo, non M3 AML, kod kojih je započeto standardno lečenje, a koji su dijagnostikovani i lečeni u Klinici za hematologiju Kliničkog centra Vojvodine u periodu od jula 2012. do marta 2014. Određivanje ekspresije gena EVI1 je vr&scaron;eno pomoću real time kvantitativne PCR (qPCR) metode, tehnikom TaqMan, a relativna ekspresija EVI1 gena je određena primenom &Delta;&Delta;Ct metode.&nbsp; REZULTATI: Medijana starosti bolesnika pri postavljanju dijagnoze AML je bila 52 godine (23-80). Ustanovljena je statistički značajna razlika između ekspresije gena EVI1 kod zdravih osoba (kontrolna grupa) i obolelih od akutne mijeloidne leukemije (p=0.008). Računajući relativnu ekspresiju, 13,2 % bolesnika je imalo visoku ekspresiju (overexpression) gena EVI1. U odnosu na kliničke i laboratorijske karakteristike bolesnika (kao &scaron;to su pol, starost, parametri krvne slike, nivo laktat dehidrogenaze, procenat blasta u perifernoj krvi i ko&scaron;tanoj srži, potom tip akutne mijeloidne leukemije, performans status, komorbiditetni indeks) nije ustanovljena statistički značajna razlika između bolesnika sa visokom ekspresijom EVI1 gena i ostalih bolesnika. Postoji statistički značajna povezanost visoke ekspresije EVI1 gena i nepostojanja NPM1 mutacije (p=0,031), kao i između visoke ekspresije EVI1 gena i prisustva monozomije 7 (p=0,047). Visoka ekspresija EVI1 gena je povezana sa kraćim preživaljvanjem bez dogaĎaja (p=0,004), kao i sa kraćim ukupnim preživljavanjem (p=0,025).&nbsp; ZAKLJUČCI: Postoji značajno povećana ekspresija gena EVI1 kod obolelih od AML u odnosu na zdrave kontrole. Visoka ekspresija EVI1 gena je faktor lo&scaron;e prognoze kod obolelih od akutne mijeloidne leukemije i u kombinaciji sa drugim prognostičkim markerima, doprinosi boljoj risk stratifikaciji ovih bolesnika.</p> / <p>INTRODUCTION: Acute myeloid leukaemia (AML) represents a heterogenous group of diseases in terms of morphology, cytogenetics, molecular genetics, so it can be divided into distinct clinical and biological entities, with variable responsiveness to therapy and different treatment outcome. Human EVI1 (ecotropic virus integration-1) gene plays a role of multifunctional nuclear transcriptional factor, not only in normal, but also in malignant haematopoiesis. There are more and more investigations indicating high EVI1 expression (EVI1 overexpression) as a negative prognostic marker in AML.&nbsp; PURPOSES: The main goal of this investigation was to examine the clinical and prognostic significance of EVI1 expression in AML, as well as to investigate whether there was any association of EVI1 overexpression with cytogenetic abnormalities and other standard molecular prognostic factors, such as FLT3 mutation and nucleophosmin 1 (NPM1) mutation.&nbsp; PATIENTS AND METHODS: This prospective study included 38 adult newly diagnosed patients with de novo nonM3 AML, in whom a standard treatment was started at Clinic of Haematology, Clinical center of Vojvodina in the period from July 2012 to March 2014. EVI1 expression was analyzed by real-time quantitative polymerase chain reaction using TaqMan, and relative EVI1 expression was determined by &Delta;&Delta;Ct method.&nbsp; RESULTS: Median age of patients at diagnosis was 52 (aged 23-80). There has been determined statistically higher EVI1 expression in our AML patients than in healthy volunteers (control group) (p=0.008). The relative EVI1 overexpression was observed in 13.2% of the patients. No significant differences in clinical and laboratory patient data (including sex, age, whole blood counts, lactate dehydrogenase level, peripheral and bone marrow blast percentages, type of AML, performance status, comorbidity index) were observed between patients with high EVI1 expression and patients without high EVI1 expression. Our investigation revealed inverse correlation of high EVI1 expression and nucleophosmin 1 mutation (p=0,031). Also high EVI1 expression was significantly associated with monosomy 7 (p=0,047). Survival analysis revealed significantly inferior event free survival (p=0,004) and overall survival (p=0,025) for patients with high EVI1 expression compared to the other patients.&nbsp; CONCLUSION: EVI1 expression is significantly higher in AML patients compared to healthy controls. High EVI1 expression is a poor prognostic marker for patients with AML, and in combination with other well established prognostic markers, contributes to better risk stratification of these patients.</p>