Adapted Lethality: What We Can Learn from Guinea Pig-Adapted Ebola Virus Infection Model
Table 2
Genetic changes occurring in different adaptation series and reverse genetics experiments and their relevance to the development of GPA-EBOV virulence/lethality.
Viral ORF
Nucleotide position
Amino acid substitution
Relevance to adaptation
Comment
EBOV-8mc adaptation series
NP
1852
None
No
Synonymous
2410
None
No
Synonymous
2411
Unlikely
Conservative, may play a supportive role in adaptation
GP
6924 (insertion)
Frameshift
No
Clones with or without those GP mutations do not differ from each other in their pathogenicity in guinea pigs
7228
No
VP30
9595
None
No
Located in 3′-untranslated region
VP24
10557
Probably
At least, one of those three VP24 mutations induces major structural rearrangements in EBOV-8mc VP24, which are presented as gel mobility shift in electrophoresis
10784
Probably
10904
Probably
L
14038
Unlikely
Conservative, may play a supportive role in adaptation
EBOV-5K adaptation series
VP24
10838
No
Is acquired in the course of passage in NHPs or L68 cells, prior to adaptation
10907
Probably
Acquired during adaptation, lies close to EBOV-8mc VP24
EBOV-GPA-P7 series
NP
1781
No
Is found in nonadapted pre-GPA clone
2043
No
Is found in nonadapted pre-GPA clone
2092
None
No
Synonymous
2100
)
No
Occurred at passage 1 after pre-GPA, before the acquisition of lethality
2164
None
No
Synonymous
2166
Probably
Occurred at passage 3, when the first lethal outcome was recorded, heterogenous site until fixed at passage 5, concomitant with 40% lethality
2188
None
No
Synonymous
2191
None
No
Synonymous
2209
None
No
Synonymous
2222
None
No
Synonymous
2233
None
No
Synonymous
2260
None
No
Synonymous
2261
No
Occurred at passage 1 after pre-GPA, before the acquisition of lethality
2409
No
Is found in nonadapted pre-GPA clone
VP40
2456
No
Occurred at passage 1 after pre-GPA, before the acquisition of lethality
5576
None
No
Synonymous
VP24
5597
None
No
Synonymous
10557
Probably
Occurred at passage 6, concomitant with lethality increase to 80%
10784
Probably
Occurred at passage 3, when the first lethal outcome was recorded, heterogenous site until fixed at passage 5, concomitant with 40% lethality
10805
Probably
Occurred at passage 7, concomitant with full lethality
L
12286
Probably
Occurred at passage 7, concomitant with full lethality
16821
None
No
Synonymous
Reverse genetics of EBOV-8mc mutations
VP24
10422
Definitely
Derived from the blood of an animal, which died after inoculation with a nonlethal recombinant rEBOV-NP/8mc, F648L virus. When introduced into an otherwise wild-type Zaire EBOV genome by reverse genetics, this mutation alone confers full lethality to guinea pigs