One step closer to a cure...

Over the last few months, there have been many stories published about Timothy Brown, ''The Berlin Patient'' who was cured of HIV through a long and risky procedure of chemotherapy, radiation and a stem cell transplant. He received all of these treatments thanks to a doctor who was not afraid to think outside of the box. Now, 5 years later, there is still no trace of HIV in his system.

But unfortunately, his case will most likely remain unique. Not only is it extremely expensive, it is also hard to find a suitable donor as you need to find one with a ''mutation''. About ten years ago, it was discovered that people who have inherited what is known as the delta32 CCR5 from both parents are resistant to getting infected by most forms of HIV. These cells are necessary for the kind of transplant this particular patient underwent. And since it's found in only 2 percent of Caucasian Americans and Western Europeans, about 4 percent of people from Scandinavian descent and so far never in any Africans, African Americans or Asians, donors are relatively hard to find.

An HIV diagnosis today means taking drug cocktails that can cost up to $1,000 per month. But even religiously taking the medication every day will not eliminate the disease - it only suppresses it without providing a cure. Current research seems to point toward a possibility to change this. At the UCLA AIDS institute, scientists are working on experiments to develop medication that might completely eradicate HIV from the human body. With the support of the National Institute of Allergy and Infectious Diseases, a division of the National Institutes of Health, they are using mice implanted with human tissue, modified to resemble the immune systems of human beings. One of the initiators of this new approach is Jerome Zack, director of the UCLA Center for Aids Research and UCLA professor in the departments of microbiology, immunology and molecular genetics and medicine.

One of the reasons HIV has been so evasive is its ability to hide inside our bodies. HIV infects a kind of white blood cell known as CD4 lymphocytes, a very important factor in human immune response. In other words, it infects the very cells that are supposed to rub out viral infections. HIV replicates in these CD4 cells when triggered by an infection. But some cells become inactive before the virus replicates. They go into a resting mode and allow it to lie dormant for years, representing a hidden reservoir of HIV. When treatment stops, the resting cells eventually become active again, allowing the virus to replicate and causing the patient to develop full-blown AIDS.

''As soon as you know you have HIV, you already have one million latent cells in your body that you can’t do anything about,'' Zack states. The mouse model his team has developed expands the repertoire of testing available, which will also include primate models and, eventually, humans. As a result, scientists have gained a valuable tool in discovering effective therapies and drugs, as they can now avail themselves of subjects carrying a live virus they are able to control.