Download HIV and AIDS

HIV and AIDS
Immune System Overview
HIV
lives in
these
cells
Review how viruses replicate and
are transmitted
HIV life cycle
Typical progress of HIV infection
Importance of HIV as case study
1. Diversity of viruses and viral types:
Importance of HIV as case study
2. Metabolism and genetics:
Importance of HIV as case study
3. Environment of viruses:
•
•
provirus stage lives inside cell, integrated
with cell’s genome
virion is particle that moves from cell to
cell. In case of HIV, lives in blood and
other body fluids:
– blood: 1000-100,000 virions per ml
– Semen: 10-50 virions per ml
– Saliva, vaginal secretions—lower
concentrations
Importance of HIV as case study
3. Environment of viruses:
• Epidemiology of spread of AIDS
In U.S., new cases down
throughout 1990’s, now on
rise again—why?
Importance of HIV as case study
4. Immune Response:
• Complicated because HIV infects cells of
immune system
• HIV doesn’t kill, just lowers body defenses
as T-cell levels drop
Challenges
• Treat patients to prevent cell-to-cell
infection by virions within body
• Stop spread of virions from person to
person (role of sex education, condoms,
status of women)
• Develop a vaccine—why so difficult (by
end of this unit understand is goal!)