A previously undescribed archaeal virus suppresses host immunity.

ABSTRACT: Extremophilic archaea can have chronic viral infections that are well-tolerated by the hosts and may potentially protect against more lethal infections. Here we show that a natural Haloferax strain (48N), is chronically infected by a lemon-shaped virus. This viral infection is not cleared spontaneously, despite the multiple defense systems of the host. Curing 48N of its virus led to radical changes in the gene expression profile of 48N and a dramatic improvement in its growth rate. Remarkably, the cured 48N is the fastest-growing haloarchaeon reported to date, with a generation time of ~107 min at 45 °C, and faster than any known Haloferax species at this temperature. The virus subverts host defenses by reducing its transcription, including the CRISPR spacer acquisition machinery. Nonethel

SUBMITTER: Turgeman-Grott I 

PROVIDER: S-EPMC12714723 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature