Dengue viruses

Dengue virus

Properties

  • Genus Flavivirus, Family Flaviviridae
  • Enveloped, spherical, about 40 –50 nm in diameter.
  • Monopartite, linear, ssRNA(+) genome of about 10-12 kb.
  • Spherical nucleocapsid
  • Lipid bilayer envelope
  • Replication in cytoplasm

VIRION

  • Causes dengue and dengue hemorrhagic fever
  • Arbovirus or Arthropod-borne virus
  • Transmitted by mosquitoes
  • Has 4 serotypes (DEN-1, 2, 3, 4)

Each virus serotype elicits specific lifetime immunity against the same (homologous) serotype, as well as short-term cross-immunity against the other three serotypes, which may last several months. All four serotypes can cause severe and fatal disease. There is genetic variation within each of the four serotypes, and some genetic variants of each serotype appear to be more virulent or have greater epidemic potential.

Genome 

  • Positive  single-stranded RNA ~ 11 kb
  • Single open reading frame
  • 3 structural proteins
  • 7 nonstructural proteins

GENE EXPRESSION

The whole genome is translated in a polyprotein, which is processed co- and posttranslationally by host and viral proteases.

REPLICATION

CYTOPLASMIC

  1. Virus attaches to host receptors and is endocytosed into vesicles in the host cell.
  2. Fusion of virus membrane with the vesicle membrane; RNA genome is released into the cytoplasm.
  3. The positive-sense genomic ssRNA is translated into a polyprotein, which is cleaved into all structural and non structural proteins.
  4. Replication takes place at the surface of endoplasmic reticulum. A negative-sense complementary ssRNA is synthesized using the genomic RNA as a template.
  5. New genomic RNA is synthesized using the negative-sense RNA as a template.
  6. Virus assembly occurs at the endoplasmic reticulum. The virion buds at the endoplasmic reticulum, is transported to the Golgi apparatus, and then bud from the cell membrane.

 

Responses

  1. Hi, You have nice drawings of the dengue virus. I would like to use one or two of them for a talk at the Asia Pacific Dengue Workshop (a WHO-SIngapore) workshop. Your permission is sought please. THanks

    • Sure, If you want to add more information beside the detail,so you can find out from the articles of NCBI pubmed website with high impact factor


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: