PhD Projects » ESR 9: Impact of host immune pathways on virus evolution

@article{Lezcano2023,

title = {Parallel evolution and enhanced virulence upon in vivo passage of an RNA virus in \textit{Drosophila melanogaster}.},

author = {Oscar M. Lezcano and Lara Fuhrmann and Gayatri Ramakrishnan and Niko Beerenwinkel and Martijn A. Huynen and Ronald P. van Rij },

doi = {10.1093/ve/vead074},

year  = {2023},

date = {2023-12-15},

urldate = {2023-12-15},

journal = {Virus Evol},

volume = {9},

issue = {2},

pages = {vead074},

abstract = {Virus evolution is strongly affected by antagonistic co-evolution of virus and host. Host immunity positively selects for viruses that evade the immune response, which in turn may drive counter-adaptations in host immune genes. We investigated how host immune pressure shapes virus populations, using the fruit fly Drosophila melanogaster and its natural pathogen Drosophila C virus (DCV), as a model. We performed an experimental evolution study in which DCV was serially passaged for ten generations in three fly genotypes differing in their antiviral RNAi response: wild-type flies and flies in which the endonuclease gene Dicer-2 was either overexpressed or inactivated. All evolved virus populations replicated more efficiently in vivo and were more virulent than the parental stock. The number of polymorphisms increased in all three host genotypes with passage number, which was most pronounced in Dicer-2 knockout flies. Mutational analysis showed strong parallel evolution, as mutations accumulated in a specific region of the VP3 capsid protein in every lineage in a host genotype-independent manner. The parental tyrosine at position ninety-five of VP3 was substituted with either one of five different amino acids in fourteen out of fifteen lineages. However, no consistent amino acid changes were observed in the viral RNAi suppressor gene 1A, nor elsewhere in the genome in any of the host backgrounds. Our study indicates that the RNAi response restricts the sequence space that can be explored by viral populations. Moreover, our study illustrates how evolution towards higher virulence can be a highly reproducible, yet unpredictable process.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Arbovirus-vector protein interactomics identifies Loquacious as a co-factor for dengue virus replication in Aedes mosquitoes},

author = {Benoit Besson and Oscar M. Lezcano and Gijs J Overheul and Kirsten Janssen and Cornelia G. Spruijt and Michiel Vermeulen and Jieqiong Qu and Ronald P. van Rij},

doi = {10.1371/journal.ppat.1010329},

year  = {2022},

date = {2022-09-08},

urldate = {2022-09-08},

journal = {PLoS Pathogens},

volume = {18},

issue = {9},

pages = {e1010329},

abstract = {Efficient virus replication in Aedes vector mosquitoes is essential for the transmission of arboviral diseases such as dengue virus (DENV) in human populations. Like in vertebrates, virus-host protein-protein interactions are essential for viral replication and immune evasion in the mosquito vector. Here, 79 mosquito host proteins interacting with DENV non-structural proteins NS1 and NS5 were identified by label-free mass spectrometry, followed by a functional screening. We confirmed interactions with host factors previously observed in mammals, such as the oligosaccharyltransferase complex, and we identified protein-protein interactions that seem to be specific for mosquitoes. Among the interactors, the double-stranded RNA (dsRNA) binding protein Loquacious (Loqs), an RNA interference (RNAi) cofactor, was found to be essential for efficient replication of DENV and Zika virus (ZIKV) in mosquito cells. Loqs did not affect viral RNA stability or translation of a DENV replicon and its proviral activity was independent of its RNAi regulatory activity. Interestingly, Loqs colocalized with DENV dsRNA replication intermediates in infected cells and directly interacted with high affinity with DENV RNA in the 3' untranslated region in vitro (KD = 48-62 nM). Our study provides an interactome for DENV NS1 and NS5 and identifies Loqs as a key proviral host factor in mosquitoes. We propose that DENV hijacks a factor of the RNAi mechanism for replication of its own RNA.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}