Vih (ingles)

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  • Publicado : 17 de enero de 2012
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What is HIV?. How does?.

HIV is a virus of the family of retroviruses, with the ability to infect humans and cause an immune box slowly.

The first cases were described in 1981 in the UnitedStates, but probably existed since the mid-twentieth century in Africa. HIV-1 was described in 1993 and later discovered another retrovirus in Africa capable of producing minor immunodeficiency andaggressiveness which is called HIV-2. HIV-1 is the cause of the global pandemic and that exists in our country.

Retroviruses possess RNA genetic material capable of forming DNA through its reversetranscriptase enzyme, and then integrated the DNA into the genome of infected cells.

Schematically the structure of HIV is made up of 3 layers:

Lipoprotein or outer casing.
 Intermediate orparent.
Internal nucleocapsid or core.

The genome has several genes that encode various viral elements. There are 3 structural genes gag, pol and env, and various regulatory genes.

LIFE CYCLE OF HIVHIV penetrates inside the host cell by binding to the CD4 molecule via the gp120 protein of the virus. The CD4 molecule is mainly found in CD4 + lymphocytes and other cells of the mononuclearphagocytic system. Have recently identified the CCR5 and CXCR4 coreceptors for different HIV subtypes have different binding affinity. After the fusion of HIV with the cell surface, the core of the virusenters the cytoplasm of the cell.

Within the cell occurs retrotranscription creating a copy of the virus RNA into DNA which then integrates into the genome of infected cells. After the integrationof viral DNA replication can start virus mRNA synthesized that enters the cytoplasm where it will lead to the synthesis of different viral components that are assembled to form a budding virion, andit comes out through the cell membrane.

Replication and cell destruction

In an infected patient has a high viral replication and constant, although there are no symptoms. The formation of new...
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