title: Infectivity of Immature Neurons to Zika Virus: A Link to Congenital Zika Syndrome.
abstract: BACKGROUND
  Epidemiological data strongly suggest that microcephaly cases in Brazil are associated with the ongoing epidemic of Zika virus (ZIKV). In order to further solidify the possible link, we investigated the infectivity of ZIKV using various neuroblastoma (NB) cell lines.
  
  
  METHODS
  Six undifferentiated, two terminally differentiated and two retinoic acid (RA) -induced, partially differentiated cell lines were exposed to ZIKV strain PRVABC59, which is genetically similar to the French Polynesia strain, with 97-100% genetic homology to the current ZIKV strain found in Brazil. All infections were confirmed by real-time PCR (RT-qPCR), immunofluorescence assay (IFA) probing with anti-flavivirus E antibody, and evaluation of cytopathic effects.
  
  
  RESULTS
  ZIKV infected all six undifferentiated NB cell lines. In five out of six NB cell lines, between 90 and 70% cells were positive by IFA whereas for one cell line, CCL-127, ~80% of cells were positive for ZIKV as determined by IFA but showed persistent infection. Two differentiated cell lines, JFEN and T-268, were highly resistant to ZIKV with <1% of the cells being susceptible, as determined by IFA and confirmed by qRT-PCR. Two retinoic acid (RA)-induced NB partially differentiated cell lines showed no difference in permissiveness as compared to their undifferentiated mother cell lines.
  
  
  CONCLUSIONS
  These findings strengthen the reported association between high incidences of microcephaly and ZIKV infection in newborns in Brazil. Our results suggest that the undifferentiated neurons are highly permissive to ZIKV infection, as one would expect during the early stages of neurogenesis in fetal brains; whereas differentiated neurons, representative of adult brain neurons, are relatively resistant to the virus, which explains the rare occurrence of neurological complications in adults infected with ZIKV. Our studies confirm the neurotropism of the ZIKV strain closely related to the current epidemic in Latin America.
authors.affiliation: Claflin University, South Carolina Center for Biotechnology, 400 Magnolia Street, 29115 Orangeburg, SC, United States.
authors.forename: Brandon W
authors.initials: BW
authors.lastname: Hughes
authors.affiliation: Claflin University, South Carolina Center for Biotechnology, 400 Magnolia Street, 29115 Orangeburg, SC, United States.
authors.forename: Krishna C
authors.initials: KC
authors.lastname: Addanki
authors.affiliation: Claflin University, South Carolina Center for Biotechnology, 400 Magnolia Street, 29115 Orangeburg, SC, United States.
authors.forename: Ahila N
authors.initials: AN
authors.lastname: Sriskanda
authors.affiliation: Claflin University, South Carolina Center for Biotechnology, 400 Magnolia Street, 29115 Orangeburg, SC, United States.
authors.forename: Ewen
authors.initials: E
authors.lastname: McLean
authors.affiliation: Claflin University, South Carolina Center for Biotechnology, 400 Magnolia Street, 29115 Orangeburg, SC, United States. Electronic address: obagasra@claflin.edu.
authors.forename: Omar
authors.initials: O
authors.lastname: Bagasra
mesh_terms: D000818:Animals; D002460:Cell Line; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D058953:Neural Stem Cells / Q000473:pathology / Q000821:virology*; D009474:Neurons / Q000473:pathology / Q000821:virology*; D060888:Real-Time Polymerase Chain Reaction; D013577:Syndrome; D000071244:Zika Virus / Q000502:physiology*; D000071243:Zika Virus Infection / Q000635:transmission / Q000821:virology*
keywords: Microcephaly; Neuroblastoma; Neurogenesis; Terminally differentiated; Undifferentiated; Zika virus