Influenza Flashcards
Influenza Baltimore
-ssRNA
Influenza Virion
enveloped, contains HA antigen spikes and NA antigen spikes
- HA glycoprotein hemagglutinin
- NA glycoprotein neuraminidase
- M1 matrix proteins
- M2 ion channel protein
Influenza genome
segments of -ssRNA. Segments 1-6 code for one viral protein and 7-8 code for two.
M2 ion channel
- proton channel that mediates the pH level of viral membrane during cell entry.
- in the viral envelope allows H+ ions to penetrate the virion and weakens M1 matrix protein.
when influenza ph drops
vRNPs can be delivered into nucleus. RNP: RNA-dependent RNA polymerase
influenza entry
- RNPs are released into the cytoplasm and then transported into the nucleus.
- In the nucleus, viral RdRp initiates viral RNA synthesis.
- Cap Snatching of host pre-mRNA molecules
- Viral mRNAs are transported to cytoplasm for translation.
Influenza NS1
inhibits interferon and the induction of antiviral response.
- binds dsDNA and sequesters it
- inhibits pkr
H, N, and M2 are …
processed in the ER, glycosylated in the Golgi, and transported to host cell membrane
H1N1
antigenic shift resulting in triple reassortment of human, avian and swine. Spanish flu and Swine flu
H5N1
jumped to humans in the 90s. A single mutation could make it spread much more efficiently. Farm disinfection, killing infected birds and carriers, careful disposal of their carcasses.
H7N9
combination between birds and humans, short-lived
influenza syncitia formation
fusion b/c receptor proteins on cell surface cause host neighbor cells to bind
influenza exit
progeny virions occur by budding at cell membrane
antigenic shift
recombination events b/c segmented genome
-Epidemics, pandemics, emerging flu virus (less selective)
antigenic drift
HA/NA proteins drift out of recognition
-this is why seasonal vaccine, regular mutations in genome
