An Ecological Framework of the Human Virome Provides Classification of Current Knowledge and Identifies Areas of Forthcoming Discovery

Parker, Michael T.

To address this issue, an ecological framework can be constructed for more informative classification of the virome based on how viruses fill niches in humans. Here, I describe a conception of the human virome with three general classifications of virus types: Parasitic, Commensal, and Mutualistic ( Figure 1 ). Within these groupings are subcategories containing more specific characteristics germane to different viral groups. Table 1 illustrates how representative members of the human virome spanning a vast array of families, replication schemes, genome architectures, and tropisms can be succinctly classified with this scheme. This arrangement provides functional information about the nature and plasticity of virus-host interaction, the most critical defining characteristic of a virus in the context of human health, in a way absent in the more classical types of organization mentioned above. In the rest of this review, I will characterize each grouping and provide examples from the literature supporting this classification. The application of this scaffold will not only deepen the understanding of known virus-host interactions in the ecological context of the virome, but will also identify logical next steps and gaps in current knowledge that are tantalizing areas for future exploration.