Replication of Chimeric Yellow Fever Virus-Dengue Serotype 1–4 Virus Vaccine Strains in Dendritic and Hepatic Cells

Abstract

ChimeriVax-dengue (DEN) viruses are live attenuated vaccine candidates. They are constructed by replacing the premembrane (prM) and envelope (E) genes of the yellow fever (YF) 17D virus vaccine with the corresponding genes from wild-type DEN viruses (serotypes 1-4) isolated from humans. In this study, the growth kinetics of ChimeriVax-DEN1-4 and parent viruses (wild-type DEN-1-4 and YF 17D) were assessed in human myeloid dendritic cells (DCs) and in three hepatic cell lines (HepG2, Huh7, and THLE-3). In DC, ChimeriVax-DEN-1-4 showed similar growth kinetics to their parent viruses, wild-type DEN virus (propagated in Vero cells), or YF 17D virus (peak titers ~3-4.5 log(10) plaque-forming units (PFU)/mL at 48-72 hours post-infection). Parent wild-type DEN-1-4 viruses derived from C6/36 mosquito cells did not show any growth at a multiplicity of infection of 0.1 in DCs, except for DEN-2 virus, which grew to a modest titer of 2.5 log(10) PFU/mL at 48 hours post-infection. ChimeriVax-DEN1-4 grew to significantly lower titers (2-5 log(10) PFU/mL) than YF 17D virus in hepatic cell lines THLE-3 and HepG2, but not in Huh7 cells. These experiments suggest that ChimeriVax-DEN1-4 viruses replicate similarly to YF-VAX in DCs, but at a lower level than YF 17D virus in hepatic cell lines. The lack of growth of chimeric viruses in human hepatic cells suggests that these viruses may be less hepatotropic than YF 17D virus vaccine in humans.

A live, attenuated recombinant West Nile virus vaccine

“…There are no previous data on the sites of replication of YF 17D vaccine. Studies of other flaviviruses suggest that the initial site of replica- tion is skin at the site of inoculation (11,12), specifically Langerhans' cells (LC) (13), and that activated LC migrate to draining lymph nodes under the control of IL-1␤ (14), where additional replication occurs and antigen processing is initiated (15). The virus is believed to reach the blood stream via efferent lymphatics and the thoracic duct (16).…”

Development of sanofi pasteur tetravalent dengue vaccine

“…Replication of all chimeric viruses in HepG2 and THLE 3 cells, but not in Huh7, was markedly lower than that of YF-VAX. 16 Differences in findings between cell lines may be explained by the fact that Huh7 cells are permissive to replication of many viruses, irrespective of their attenuated phenotype. These results nevertheless suggest that the CYD1-4 viruses are less hepatotropic that YF 17D virus vaccine in humans.…”

“…Interactions between human DCs and wild-type (wt) dengue viruses have been well documented, 14,15 it was therefore interesting to compare immune consequences of infection with attenuated vaccine viruses versus their wt parents. We investigated the infectivity of the four CYD viruses in monocyte-derived human DCs, 16 as well as the consequences of infection in terms cellular activation and maturation and the secretion of pro-and anti-inflammatory cytokines, chemokines and type I interferons. 17 The CYD1-4 viruses were seen to induce DC maturation and a controlled response, accompanied by limited inflammatory cytokine production and consistent expression of anti-viral type I IFN, in agreement with neutralizing antibodies.…”

In vitro and in vivo characterization of chimeric duck Tembusu virus based on Japanese encephalitis live vaccine strain SA14-14-2

“…Especially, using live attenuated strains as the genetic backbone, multiple versions of chimeric flaviviruses have been successfully designed and well-explored in the development of vaccines against DENV, WNV, JEV and TBEV (Brandler et al, 2005;Chambers et al, 1999;Guirakhoo et al, 2000;Guy & Jackson, 2016;Pletnev et al, 2002;Wright et al, 2008). The JEV live attenuated vaccine virus SA14-14-2 has been widely used in most JEV-endemic countries (Yu, 2010) with an excellent safety and efficacy profile (Bista et al, 2001;Kumar et al, 2009;Tandan et al, 2007).…”