Incucyte data for progeny virus derived from insect cells with or without methyltransferase inhibitor

Arthropod endosymbiont Wolbachia pipientis is part of a global biocontrol
strategy aimed at reducing the spread of mosquito-borne RNA viruses such
as alphaviruses. Our prior work examining Wolbachia-mediated pathogen
blocking has demonstrated (i) the importance of a host cytosine
methyltransferase, DNMT2, in Drosophila, and (ii) viral RNA as a target
through which pathogen-blocking is mediated. Here we report on the role of
DNMT2 in Wolbachia induced virus inhibition of alphaviruses in Aedes sp..
Mosquito DNMT2 levels were altered in the presence of both viruses and
Wolbachia, albeit in opposite directions. Elevated levels of DNMT2 in
mosquito salivary glands induced by virus infection were suppressed in
Wolbachia colonized animals coincident with a reduction of virus
replication, and decreased infectivity of progeny virus. Ectopic
expression of DNMT2 in cultured Aedes cells was proviral increasing
progeny virus infectivity, and this effect of DNMT2 on virus replication
and infectivity was dependent on its methyltransferase activity. Finally,
examination of the effects of Wolbachia on modifications of viral RNA by
LC-MS showed a decrease in the amount of 5-methylcytosine modification
consistent with the down-regulation of DNMT2 in Wolbachia colonized
mosquito cells and animals. Collectively, our findings support the
conclusion that disruption of 5-methylcytosine modification of viral RNA
is an important mechanism operative in pathogen blocking. These data also
emphasize the essential role of epitranscriptomic modifications in
regulating fundamental processes of virus replication and transmission.