Human Immunodeficiency Virus (HIV) Flashcards
When did the HIV outbreak first start?
1981 San Francisco among the gay male community. It is retroviral (RNA genome).
It is sexually transmitted, mechanical transmission, and vertical transmission (prenatal placental, perinatal, post natal breast milk)
What are the 2 types of HIV?
HIV 1 (virus) causes AIDS (acquired immunodeficiency syndrome) which is the disease. It has high homology with chimpanzee SIV.
HIV 2 causes milder symptoms and isn’t lethal. Homology with simian immunodeficiency virus (SIV) which is milder and less virulent.
The structure of HIV:
2 ss positive sense RNA strands. 2 enzymes (RT and integrase). Surrounded by a p24 protein capsid. This is surrounded by a p17 matrix protein that acts as a glue in-between the p24 capsid and the outer envelope which is acquired when the virus buds from the host. The envelope has surface glycoproteins gp120 and gp41.
What is the cellular response to HIV?
HIV affects macrophage and CD4 T cells (central in orchestrating the immune response). Once CD4T cells are activated by binding with the antigen presented by an APC, they will further activate CD8T cells which will seek out the virally infected cells and kill them.
What are some examples of opportunistic infections associated with HIV 1?
- pneumocystis sp.
- malaria
- candida sp (thrush)
- TB (mycobacterium tuberculosis)
- HPV which can be genital, oral or on the skin and it can cause cancers.
What is AIDS?
What are the challenges with HIV vaccines?
- mucosal infection - subcutaneous vaccines lead to IgG poor protection of mucosal surfaces
- there is no good animal model
- mutation rate 1:10,000 bp - in RNA viruses mutations are quicker.
What is triple therapy?
Highly active anti-retroviral therapy (HAART).
It involves giving HIV patients a mixture of anti-retroviral therapies that target different aspects of the virus life cycle.
