Poxviruses and Innate Immunity

Flashcards about Poxviruses and their interaction with host immunity.

Poxvirus

A family of dsDNA viruses that includes variola virus, the causative agent of smallpox.

Variola Virus

The causative agent of smallpox, one of the deadliest viruses in the poxvirus family.

Vaccinia Virus (VACV)

A strain of poxvirus used as a smallpox vaccine and a model for studying viral countermeasures to host immunity.

OAS/RNase L system

A host antiviral pathway activated by dsRNA, leading to the degradation of viral and cellular single-stranded RNA.

PKR system

A host antiviral pathway activated by dsRNA, leading to the inhibition of protein synthesis.

Interferons (IFNs)

Signaling molecules produced in response to viral infections that induce the expression of OAS and PKR genes.

2-5A

Unusual 20-to-50 linked oligoadenylates produced by OAS proteins, which activate RNase L.

dsRNA

Double-stranded RNA, a viral byproduct that activates PKR and OAS proteins in the host cell.

Dcp2

A decapping enzyme containing a nudix/MutT hydrolase motif that removes m7-GDP caps from mRNA.

Xrn1

A host 50-to-30-exoribonuclease that degrades decapped 50-monophosphorylated RNAs.

D9 and D10 proteins

VACV proteins with nudix/MutT motifs that suppress host mRNA translation and maintain stages of the virus-replication cycle.

Host-range effect

The phenomenon where a virus replicates efficiently in some cell types but poorly in others.

Viral morphogenesis

The process by which new virus particles are assembled within the host cell.

Ara C

A drug that prevents viral DNA replication and inhibits OAS/RNase L activation.

E3L and K3L

VACV proteins that inhibit PKR and OAS activation; E3L sequesters dsRNA, while K3L is a pseudosubstrate inhibitor of PKR.

Nudix/MutT hydrolase motif

A protein domain present in D9 and D10 proteins involved in mRNA decapping.

50-to-30 exoribonuclease

Enzyme that degrades RNA from the 5' to 3' end after decapping.

mRNA decay pathway

Cellular process by which messenger RNA molecules are degraded.

Plaque size

A measure of viral infectivity, with smaller sizes indicating decreased ability to spread.

Ribosome degradation

Breakdown of ribosomes, often indicative of RNase L activity.

shRNA

Short hairpin RNA, used to deplete cells of specific proteins like RNase L.

Immunostaining

A technique using antibodies to detect specific molecules, such as dsRNA, in cells.

IRF3

Interferon regulatory factor 3, a transcription factor involved in innate immune responses.

Respiratory infection mouse model

Animal model used to study viral infections of the respiratory system.

siRNA

Small interfering RNA, used to deplete cells of specific proteins for research purposes.