Section 6.4 Flashcards
Filoviruses genome
non-segmented -ve sense ssRNA (large)
Fun fact about filoviruses
most of the viral proteins are part of or in the virion
what proteins are in the filovirus virion (6)
1- nucleoprotein coats the RNA
2- RNA pol (L) & RNA pol Cofactor (VP35) at 3’ end
3- Matrix protein (V40)
4- Envelope glycoproteins (GP) cleaved into GP1 and GP2
5- Transcription Factor (V30)
6- Membrane protein (V24)
** it actually makes more glycoproteins that are secreted out of infected cells (help w immune evasion?)
how does ebola genome work:
Steps and facts
-ve strand RNA is template for RdRp to make transcripts for each of the proteins
- starts in the 3’ end, makes one gene, stops, moves to the next gene (etc) “ start-stop mechanism “
- transcript levels decrease from 3’ to 5’ (most NP and least L”
Ebola v.s influenza difference
ebola does transcription and replication IN CYTOPLASM (unlike influenza where it happens in nucleus)
How does Ebola attach and enter?
- GP1 envelope glycoprotein binds to cell surface receptor
- conformational change exposes fusion peptide in GP2
- envelope and cell membrane fuse
why can ebola infect so many tissues?
GP can bind to many cell surface receptors (not very specific)
EBOLA clinical facts
– scariest virus on earth - 50-90 death rate
– kills within 2 weeks of infection
– infects connective tissue of every organ leading victims to bleed out of orifices such as eyes
why is ebola so virulent? (3 reasons)
- first cells infected are part of our immune system blocking our ability to mount an immune response
2- causes blood clotting and damage to blood vessels (leads to haemorrhaging)
3- loss of BP, organ failure, death
one good thing about Ebola:
hard to transmit between humans, requires close contact due to droplet properties containing the virus (3ft)
Where does EBOLA come from?
we initially thought monkeys, NOW we are almost certain its bats
Hard to find out cuz BSL4 labs only can look at it
