Virome

Virome refers to the assemblage of viruses[1][2] that is often investigated and described by metagenomic sequencing of viral nucleic acids[3] that are found associated with a particular ecosystem, organism or holobiont.

Viruses, including bacteriophages, are found in all environments, and studies of the virome have provided insights into nutrient cycling,[4][5] development of immunity,[6] and a major source of genes through lysogenic conversion.

[7] Also, the human virome has been characterized in nine organs (colon, liver, lung, heart, brain, kidney, skin, blood, hair) of 31 Finnish individuals using qPCR and NGS methodologies.

[20][21] In order to study the virome, virus-like particles are separated from cellular components, usually using a combination of filtration, density centrifugation, and enzymatic treatments to get rid of free nucleic acids.

[25] The specificity of tRNA-based host viral assignment was confirmed by CRISPR–Cas spacer matches showing a 94% agreement at the genus level.

A viral group composed of macs from human oral samples contained three distinct photo-spacers with nearly exact matches to spacers in Actionbacteria and Bacillota.

However, due to shallow sequencing in the past, the genetic composition and diversity of tissue-resident viruses remained poorly characterized, hindering understanding of their roles in pathogenesis and viral evolution.

The study also identified selective pressures from the host and unexpected viral genome integrations, including MCPyV truncations and novel links between herpesvirus 6B and mitochondrial DNA, even in non-cancerous individuals, offering new insights into tissue-resident viruses and their potential health impacts.