Question

What is the Pathobiology of Dengue Virus and Structural- Genetics and protein ?

Answer 1

Genetics of the Dengue virus: Dengue virus contains ssRNA as its genome, in which 11000 bases are present. This genetic material codes for three structural and seven non-structural proteins. The structural proteins are 1.Capsid protein C, 2.Membrane protein M, and 3.Envelop protein E.

The envelop protein DENV E is present as a dimer on the surface of the viral particle, which will help in the attachment of virus to the host cell. The membrane protein is important in the formation and maturation of the viral particle.

The non-structural proteins are 1.NS1, 2.NS2a, 3.NS2b, 4.NS3, 5.NS4a, 6.NS4b, and 7.NS5.

Pathobiology of the Dengue virus:

The binding of DENV E to the cellular receptor causes the endocytosis of DENV, followed by the uncoating of the virus in the cytoplasm of the host cell. then the host cell's translational machinery translates the viral ssRNA into its respective polypeptide.

Then the host cell's and viral proteinases cleave the polypeptide into 10 proteins, out of which three will become structural and remaining seven will become non-structural proteins.

Then the asymmetric synthesis of RNA takes place by RNA-dependent RNA polymerase, which results in ten times more production of positive stranded RNA than negative-stranded RNA.

As viral protein and RNA particles are synthesized, the assembly of the total viral particles takes place and the egress occurs via exocytosis.

Dengue virus can inhibit the innate immunity response during its infection. The non-structural proteins play the key role in inhibiting the innate immunity response.

Thus the Dengue virus cause the Dengue fever by infecting the other cells continuously, before the immune system attacks on it.