Mechanisms Underlying ZIKV Infection Of Neural Cells

Zika virus?ZIKV?,a positive-strand enveloped RNA virus,is a member of Flavivirus genus belonging to the family Flaviviridae.Neurological disorders and microcephaly are the main symptoms of ZIKV infections.However,the mechanisms underlying ZIKV infectiton of neural cells remain to be further determined.In this study,a combination of molecular and pharmacological approaches have been used to study the infectiton of ZIKV into nerual cell.We first observed that ZIKV infection was significantly inhibited by expressing a dominant negative configuration of the EPS15 protein,siRNA knockdown of CHC or the specific inhibitor chlorpromazine.Importantly,confocal microscopy consequences showed that ZIKV particles colocalized with Rab7 or Rab5 during the early phase of infection,which was within 45 min after virus entry.ZIKV infection was also inhibited after silencing of Rab7 and Rab5.By using the specific inhibitor dynasore,siRNA knockdown,or the dominant negative mutant DN K44A,we further confirmed that ZIKV infection requires dynamin.Additionally,ZIKV entry can also be affected by overexpression of a dominant negative mutant of caveolin,siRNA knockdown of caveolin-1 or the inhibitor genistein.Futhermore,we found that ZIKV particles colocalized with clathrin at 5 min postinternalization.We observed that NH₄Cl and chloroquine can inhibit ZIKV infection effectively,indicating that a low-pH environment is required during ZIKV entry.Microtubules,actin cytoskeleton,and membrane cholesterol appear to be responsible for the endocytosis of ZIKV.These results together demonstrated that after internalization,ZIKV particles moved to early and late endosomes before releasing its RNA.In summary,our findings illustrate for the first time how ZIKV enters neural cells through the endocytic pathway.