Fig. 1 |. Petabase-scale analysis of viral nucleic acids reveals that HHV-6 is reactivated in human T cells.

a, Schematic of life cycles of endogenous human viruses. Viruses can enter a latent phase after primary infection and become reactivated following environmental cues, including drugs, immunization and other infections. b, Enumeration of BioSamples with human viruses showing signs of reactivation based on expressed viral nucleic acids in human Sequence Read Archive samples. c, Proportion of BioSamples with viral transcriptional expression annotated as T cells. These eight viruses showed evidence of reactivation specifically in T cells whereas the remaining viruses from b showed no such evidence of reactivation. d, Reanalysis of RNA-seq data from ref. 22. CD4⁺ T cells from three separate donors were either infected with HIV or mock infected and cultured for about 2 weeks. Shown is the percentage of RNA molecules aligning to the HHV-6B reference transcriptome e, Reanalysis of the data from ref. 18. Naive and memory CD4⁺ T cells were separated and cultured for 2 weeks. Shown is the percentage of RNA molecules aligning to the HHV-6B reference transcriptome. f, Quantification of HHV-6B episomal DNA from a reanalysis of ChIP–seq data from ref. 18. Shown are the percentages of DNA reads uniquely mapping to the HHV-6B transcriptome, noting the percentage of total DNA reads mapping to the HHV-6B reference genome. g, Coverage of the HHV-6B genome across two ChIP–seq libraries from different donors from ref. 18. Repetitive regions on the ends of the chromosome show no uniquely mapping reads.