Analiza metilacije promotorske regije gena BACH2 kod infekcije virusom ljudske imunodeficijencije tipa 1

master's thesis

• Title (english): Analysis of BACH2 gene promotor region methylation in infection with Human immunodeficiency virus type 1
• Author: Anita Slana
• Mentor: Petra Korać (mentor)
• Mentor: Snježana Židovec Lepej (mentor)
• Committee member: Petra Korać (predsjednik povjerenstva)
• Committee member: Snježana Židovec Lepej (član povjerenstva)
• Committee member: Goran Klobučar (član povjerenstva)
• Committee member: Ana Galov (član povjerenstva)
• Committee member: Maja Matulić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2017-05-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Zaraza virusom ljudske imunodeficijencije tipa 1 (HIV, eng. Human immunodeficiency virus type 1) povezuje se s progresivnim slabljenjem imunološkog sustava koje, ukoliko se ne liječi, uzrokuje smrt. Stanice podložne zarazi su limfociti CD4+. Tijekom infekcije dolazi do smanjenja njihovog broja u krvi HIV-pozitivnih osoba. Kao oblik liječenja HIV-pozitivnih pacijenata razvijena je antiretrovirusna terapija (ART) koja kombinira razne inhibitore virusnih proteina i dovodi do potpune supresije detektabilne viremije u pacijenata. Gen BACH2 je transkripcijski faktor koji ima ulogu u održavanju homeostaze perifernih naivnih T-limfocita, stvaranju efektorskih memorijskih T-stanica i regulaciji CD4+ senescencije. Cilj ovog istraživanja bio je analizirati razinu metilacije promotorske regije gena BACH2 kod HIV-om zaraženih osoba u odnosu na zdravu populaciju te utvrditi postoje li razlike u razini metilacije njegovog promotora koje ovise o statusu ispitanika. Ispitanici su podijeljeni u dvije skupine. Prvu skupinu činili su HIV-pozitivni pacijenti kod kojih se standardnim testovima ne može detektirati prisutnost virusnih kopija. Drugu skupinu činili su HIV-pozitivni pacijenti kod kojih je viremiju moguće detektirati te, u trenutku prikupljanja uzoraka krvi, nisu primali antiretrovirusnu terapiju. Metodom bisulfitne konverzije DNA i pirosekvenciranja odabranih regija promotora gena BACH2 određen je stupanj metilacije toga promotora. Utvrđeno je da kod obje skupine ispitanika dolazi do povećanja metilacije svih fragmenata promotorske regije u odnosu na kontrolnu zdravu skupinu što upućuje na to da hipermetilacija gena BACH2 dovodi do njegovog utišavanja koje ima ulogu u povećanju broja efektorskih T-stanica potrebnih za imunološki odgovor na zaražene stanice. Povećana metilacija CpG-otoka kod aviremičnih ispitanika može značiti trajnu promjenu u diferencijaciji T-stanica i homeostazi cijelog imunološkog sustava.

Abstract (english)

Infection with Human immunodeficiency virus type 1 (HIV-1) leads to progressive deterioration of the immune system, and if untreated, leads to death. Cells susceptible to the infection are CD4+ lymphocytes. Their count diminishes in the blood of HIV-positive people during the infection. Antiretroviral therapy (ART) has been developed as a form of treatment and it combines different viral protein inhibitors and leads to total suppression of detectible viremia in patients. BACH2 gene codes for a transcription factor with a role in homeostasis of naïve T-lymphocytes, development of effector memory T-cells and regulating CD4+ senescence. The aim of this study was to analyse methylation of BACH2 promoter region in HIV-1 infected patients in relation to healthy population and determine if there are differences in methylation regarding patient status. Two groups of patients were included in this study. HIV-positive patients in whose blood no viral copies could be detected with standardised tests were first group. HIV-positive patients whose viremia could be detected and at the time of sampling were not receiving therapy were the second group. The level of gene promotor region methylation was detected using bisulfite conversion of the DNA and pyrosequencing. It was shown that both groups of HIV-positive patients have higher BACH2 methylation in relation to the control group. This finding suggests that there has been a hypermethylation and silencing of BACH2 gene that leads to an increase in number of effector T-cells needed for immunological response to infected cells. Hypermethylation of CpG-islands in aviremic patients could represent a permanent change in T-cell differentiation and homeostasis of the entire immune system.

• Keywords: HIV; metilacija DNA; gen BACH2
• Keywords (english): HIV; DNA methylation; BACH2 gene
• Language: croatian
• URN:NBN: urn:nbn:hr:217:578174
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2018-05-22
• Created on: 2017-07-14 08:55:37