Reply to: "A global survey of alternative splicing of HBV transcriptome using long-read sequencing" (Letter)

Abstract

We read with delight and great interest the latest work by Professors Chen, Lu and their colleagues that confirmed some of the major findings reported in our recently published article, in which multiomics approaches were applied to study HBV-host interactions.1,2 Specifically, through the use of a third-generation sequencing (Iso-seq) technique that enabled the direct sequencing of long transcripts, the authors not only identified known HBV transcripts, but also discovered many previously under-characterized splicing products of HBV RNAs. Among them, of particular interest were the isoforms that resulted from RNA splicing events, A2,446T2,447/G489 and A2,446T2,447/T2,902, which were found to account for 7.3% and 3.5%, respectively, of all the spliced HBV RNA transcripts. These newly obtained data1,3,4 had thus directly substantiated the existence of the major RNA splicing events and products, based on which we showed that the translated products, HBxZ and HpZ, restricted HBV gene expression and replication, and likely contributed to the self-restrictive nature of HBV infection.2 While highlighting the fruitfulness of embracing and applying more novel techniques to investigate HBV-host interactions, these discoveries have unequivocally proven the extra coding potential of the HBV genome, which was under-appreciated.