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| − | ==Morphology==
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| − | *Fragile, enveloped RNA viruses with roughly spherical spike proteins
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| − | *Genome has 3 genes:
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| − | **''gag'': group-specific antigen coding gene, encodes capsid proteins
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| − | **''pol'': encodes reverse transcriptase (RT) and integrase
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| − | **''env'': encodes envelope spikes, and can be used in diagnosis and subunit vaccines
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| − | *Both ends of genome show a promoter (LTR: long terminal repeat)
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| − | ==Antigenicity==
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| − | *Group-specific antigens (gag's) are shared by all isolates of each virus
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| − | **This can be exploited by diagnostic tests
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| − | *Lentiviruses show variation by mutation, making vaccination difficult
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| − | ==Virulence and Pathogenesis==
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| − | *Replication involves integrating into the host cell genome:
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| − | **'''Uncoating''' to release RNA and RT
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| − | **+RNA '''transcribed''' to -DNA by RT
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| − | **-DNA becomes circular dsDNA and is '''integrated''' into host chromosome by integrase
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| − | **DNA '''codes''' for viral proteins using cellular organelles and enzymes
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| − | **Because of this technique, virus replication is much '''slower''', and retroviruses can remain '''latent'''
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| − | *Tumor production takes 2 forms:
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| − | **Viruses can carry oncogenes within their genome --> tumor production occurs quickly
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| − | **Insertion of the viral LTR switches on proto-oncogenes in the host cell genome --> tumor production can take years
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| | [[Category:Viral Organisms]] | | [[Category:Viral Organisms]] |
| | [[Category:To_Do_-_Clinical/Viruses]] | | [[Category:To_Do_-_Clinical/Viruses]] |