Herpesvirus – pathogens and lifelong companions of man

Abstract

Herpesvirusi su grupa velikih DNA virusa s karakterističnom strukturom viriona. U porodicu Herpesviridae spadaju virusi koji inficiraju sisavce, gmazove i ptice te se dijele u 3 podporodice. Unutar ove porodice poznato je više od 100 virusa od kojih čak 8 inficiraju ljude. Ljudski herpesvirusi su vrlo dobro istraživani te su sekvencirani genomi čak 6 vrsta. Svi ljudski herpesvirusi su vrlo rasprostranjeni u ljudskoj populaciji što je rezultat njihove sposobnosti da uspostave latentnu infekciju te stoga što posjeduju mnogo gena za interakciju s domaćinom. Herpesvirusi, kao drevni sporo evoluirajući DNA-virusi, su koevoluirali blisko povezani sa svojim domaćinima – kralješnjacima i najranijim hominidima, ali je njihov selektivni utjecaj postao značajan tek kad su počeli migrirati unutar populacije. Kako je otkriveno da unutar sve 3 podporodice postoji 40 konzerviranih gena, na temelju sekvenci za 6 takvih gena napravljeno je filogenetsko stablo. Time je otkriveno da se unutar svake podporodice struktura filogenetskog stabla podudara s onom organizma domaćina (sisavaca) što potvrđuje da se dogodila koevolucija. Zbog toga su se podaci iz paleontologije kralješnjaka mogli prenijeti na filogenetsko stablo herpesvirusa te se dobio vremenski okvir njihove evolucije.Herpesviruses are a group of large DNA viruses with a characteristic virion. The Herpesviridae family includes viruses that infect mammals, reptiles and birds, and is divided into 3 subfamilies. Within this family it is known more than 100 viruses, of which 8 of them infects humans. Human herpesviruses are very well researched and the genomes of 6 species have been sequenced. All human herpesviruses are widespread in human population as a result of their ability to establish latent infections and because they have many genes interacting with the host. Herpesviruses, as an ancient slowly evolving DNA viruses, coevolved closely associated with their hosts – vertebrates and early hominids, but their selective pressure became significant only when they began to migrate within the respective population. Since it was discovered that within all 3 subfamilies there are 40 conserved genes, the phylogenetic tree based on the sequence of 6 of those genes was constructed. The tree revealed that within each subfamily structure of phylogenetic tree was congruent with that of the host organism (mammals), which confirms that coevolution occured. Because the data from the paleontology of vertebrates can be translated to the herpesviral phylogenetic tree, the timeline of their evolution was obtained