• Welcome to Phoenix Rising!

    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of, and finding treatments for, complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia, long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

    To become a member, simply click the Register button at the top right.

Preprint to new paper from Prusty

Boba

Senior Member
Messages
332
Selective inhibition of microRNA processing by a herpesvirus-encoded microRNA triggers virus reactivation from latency

https://www.researchsquare.com/article/rs-820696/v1

Abstract
Herpesviruses have mastered host cell modulation and immune evasion to augment productive infection, life-long latency and reactivation thereof 1,2. A long appreciated, yet elusively defined relationship exists between the lytic-latent switch and viral non-coding RNAs 3,4. Here, we identify miRNA-mediated inhibition of miRNA processing as a novel cellular mechanism that human herpesvirus 6A (HHV-6A) exploits to disrupt mitochondrial architecture, evade intrinsic host defense and drive the latent-lytic switch. We demonstrate that virus-encoded miR-aU14 selectively inhibits the processing of multiple miR-30 family members by direct interaction with the respective pri-miRNA hairpin loops. Subsequent loss of miR-30 and activation of miR-30/p53/Drp1 axis triggers a profound disruption of mitochondrial architecture, which impairs induction of type I interferons and is necessary for both productive infection and virus reactivation. Ectopic expression of miR-aU14 was sufficient to trigger virus reactivation from latency thereby identifying it as a readily drugable master regulator of the herpesvirus latent-lytic switch. Our results show that miRNA-mediated inhibition of miRNA processing represents a generalized cellular mechanism that can be exploited to selectively target individual members of miRNA families. We anticipate that targeting miR-aU14 provides exciting therapeutic options for preventing herpesvirus reactivations in HHV-6-associated disorders like myalgic encephalitis/chronic fatigue syndrome (ME/CFS) and Long-COVID
 

Pyrrhus

Senior Member
Messages
4,172
Location
U.S., Earth
Thanks so much, @Boba , for posting this (Hennig et al., 2021) pre-print, along with the full abstract! :thumbsup:

You may find this link helpful:
Starting a discussion thread about a scientific paper: If you are starting a discussion thread about a specific scientific paper, please read this explanation of how to title your discussion thread.

Brief Summary:
  • Herpesviruses like HHV6 can exist inside a cell in at least two different states: an active (lytic) state and a latent state. Depending upon both cellular and extra-cellular conditions, the virus can decide to switch from its lytic state to its latent state, or from its latent state to its lytic state.
  • A cellular micro-RNA (miRNA) is a piece of RNA that a cell normally makes in order to suppress the production of a cellular protein.
  • The pre-print identifies a way in which a viral miRNA (called miR-aU14) suppresses processing of cellular miRNA's, including a family of cellular miRNA's called miR-30.
  • When the viral miRNA suppresses the cellular miRNA's, it "triggers a profound disruption of mitochondrial architecture."
  • When the viral miRNA suppresses the cellular miRNA's, it also impairs the interferon pathway, which is the most important pathway in the intracellular immune system.
  • When the intracellular immune system is compromised by impairing the interferon pathway, the HHV6 virus reactivates, switching from its latent state to its active (lytic) state.
  • The pre-print mentions that injecting the viral miRNA into a cell with a latent HHV6 infection causes the virus to reactivate, switching from its latent state to its active (lytic) state.
  • The authors suggest that finding some way to suppress the viral miRNA might help to prevent reactivation of latent HHV6 infections.