Get Started for FREE
Sign up with Facebook Sign up with X
I don't have a Facebook or a X account
 Your new post is loading...
Your new post is loading...
Scoop.it!
Picture bacteria and viruses locked in an arms race. For many bacteria, one line of defense against viral infection is a sophisticated RNA-guided "immune system" called CRISPR-Cas. Via BigField GEG Tech 
Scoop.it!
PubMed comprises more than 23 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Gilbert C FAURE's insight:
... a single pulse of IFN-γ in vivo within hours of infection, but without antiviral effect.
|
Scoop.it!
Understanding immunity to viruses therefore encompasses many, if not nearly all aspects of cell biology and immunology. A positive trend of the past twenty years of viral research is that the connection between viruses and innate cellular anti-viral mechanisms has cemented virology as an important sub-discipline of cell biology, and converted many virologists into at least honorary immunologists. The inherent simplicity of viruses and their marked tendency towards robust expression of their proteome and flagrant manipulation of host cells and immunity, make them superb tools to make basic discoveries.
|
For many bacteria, one line of defense against viral infection is the CRISPR-Cas system. At the center of this system is a surveillance complex that recognizes viral DNA and triggers its destruction. However, viruses can fight back and disable this surveillance complex by using anti-CRISPR proteins. For the first time, researchers have solved, using a high-resolution imaging technique called cryo-electron microscopy, the structure of viral anti-CRISPR proteins attached to a bacterial CRISPR surveillance complex, revealing precisely how viruses neutralize the bacterial defense system. The research team found that the anti-CRISPR proteins act by locking down CRISPR's ability to identify and attack the viral genome. The proteins within the complex wrap around the CRISPR RNA exposing specific sections of bacterial RNA. One type of anti-CRISPR protein covers the exposed section of CRISPR RNA, preventing the CRISPR system from scanning the viral DNA. Based on its location and negative charge, an anti-CRISPR protein acts as a DNA mimic, fooling CRISPR into binding this immobilizing protein, rather than invading viral DNA. The researchers believe that this new understanding of anti-CRISPR proteins could eventually lead to more sophisticated and effective tools for gene editing.