title: Mice with different susceptibility to Japanese encephalitis virus infection show selective neutralizing antibody response and myeloid cell infectivity.
abstract: BACKGROUND
  Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes public health problems in Asian countries. Only a limited number of JEV-infected individuals show symptoms and develop severe encephalitis, indicating host-dependent susceptibilities.
  
  
  RESULTS
  C3H/HeN and DBA/2 mice, which exhibit different mortalities when infected by intraperitoneal inoculation with JEV, were used as experimental models to compare viral pathogenesis and host responses. One hundred infectious virus particles killed 95% of C3H/HeN mice whereas only 40% of DBA/2 mice died. JEV RNA was detected with similar low levels in peripheral lymphoid organs and in the sera of both mouse strains. High levels of viral and cytokine RNA were observed simultaneously in the brains of C3H/HeN and DBA/2 mice starting on days 6 and 9 post-infection, respectively. The kinetics of the cytokines in sera correlated with the viral replication in the brain. Significantly earlier and higher titers of neutralizing antibodies were detected in the DBA/2 strain. Primary embryonic fibroblasts, bone marrow-derived dendritic cells and macrophages from the two mouse strains were cultured. Fibroblasts displayed similar JEV replication abilities, whereas DBA/2-derived myeloid antigen-presenting cells had lower viral infectivity and production compared to the C3H/HeN-derived cells.
  
  
  CONCLUSIONS
  Mice with different susceptibilities to JEV neuroinvasion did not show changes in viral tropism and host innate immune responses prior to viral entry into the central nervous system. However, early and high neutralizing antibody responses may be crucial for preventing viral neuroinvasion and host fatality. In addition, low permissiveness of myeloid dendritic cells and macrophages to JEV infection in vitro may be elements associated with late and decreased mouse neuroinvasion.
authors.affiliation: Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Shanghai Institute for Biological Sciences, Shanghai, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Vincent
authors.initials: V
authors.lastname: Deubel
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000276:immunology*; D000917:Antibody Formation / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000276:immunology / Q000473:pathology / Q000821:virology; D002460:Cell Line; D002478:Cells, Cultured; D018925:Chemokines / Q000097:blood; D004198:Disease Susceptibility; D004664:Encephalitis Virus, Japanese / Q000276:immunology / Q000472:pathogenicity* / Q000502:physiology; D004672:Encephalitis, Japanese / Q000097:blood / Q000150:complications / Q000276:immunology* / Q000821:virology*; D005260:Female; D005347:Fibroblasts / Q000821:virology; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D007249:Inflammation / Q000150:complications / Q000235:genetics / Q000473:pathology; D051379:Mice; D022423:Myeloid Cells / Q000473:pathology / Q000821:virology*; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D013997:Time Factors; D019562:Viral Load / Q000276:immunology; D014779:Virus Replication
chemical_list: D057134:Antibodies, Neutralizing; D015415:Biomarkers; D018925:Chemokines; D012333:RNA, Messenger