Dallas – Researchers have successfully infected mice with the virus that causes AIDS, a major advance in researchers’ ability to test preventive medications, treatments and vaccines.
The mice were infected after rectal transmission, the most common way HIV is spread between men. HIV attacks immune cells, and the mice have a humanized immune system to allow infection.
“If you want to figure out how to stop the spread of the virus, you have to have something like this,” said J. Victor Garcia, a professor of medicine at the University of Texas Southwestern Medical Center who led the new research. “This is the very first model where you can demonstrate transmission of HIV via a normal route.”
A report describing the mice and their susceptibility to HIV appeared online Monday in the Journal of Experimental Medicine.
HIV can enter the body through the bloodstream – via contaminated needles shared by intravenous drug users, for example. But most commonly it is transmitted via sexual contact, with the virus entering the body through the surfaces that line the oral cavity, the vagina or the rectum.
In the new study, six out of seven inoculated mice showed evidence of infection after the researchers introduced HIV particles into the mice’s rectums.
Three of four mice tested made human antibodies to the virus, just like people do. Autopsies of the mice showed they were producing HIV in lymph nodes, spleen and other immune tissues. Virus also was being produced in the lungs, intestines, and male and female reproductive tracts.
Other researchers have infected mice with HIV, Garcia said, but those animals had a less complete humanized immune system. Also, he said, in those cases the virus was transmitted with an injection, not via a rectal route.
The mice should allow researchers to search for topical antiviral medications known as microbicides that could be applied in the vagina or rectum.
