One significant challenge of HIV research is that the HIV virus infects only humans and chimpanzees -- not dogs, cats, rodents, or any other normal lab test animals. As a result, testing hypotheses about HIV transmission has been extremely difficult; infecting humans with HIV is unethical, and infecting chimpanzees with HIV is not feasible because of their protection as endangered species. However, Dr. J. Victor Garcia-Martinez of the University of Texas Southwestern has come up with a clever research technique that circumvents these constraints. This week, Garcia-Martinez gave a presentation describing new developments in his use of the "humanized mouse" to study HIV.
The mouse model is a chimera, meaning its cells are taken from two (or more) sets of genetically distinct cells. Fetal human liver and thymic tissue cells were used to repopulate the bone marrow, from which new cells were then created. The mouse thus develops a human immune system and can be infected with HIV. Garcia-Martinez previously used the mouse model to show that antiretroviral drugs given before and after HIV transmission can prevent vaginal transmission. This research implies, according to Science Daily, that high risk women might one day be able to take a regular pill to prevent HIV infection.
Having begun by studying male-to-female transmission, Garcia-Martinez is now using the humanized mouse to study male-to-male transmission. In my opinion, his work is extremely creative and his concept important -- even if I do have a hard time wrapping my head around the idea of a mouse that is part human!
The article can be found at: http://www.sciencedaily.com/releases/2009/04/090420103740.htm