New HIV Mutation Found
In Long-Term Survivors
By Anne Harding

CHICAGO (Reuters Health) - An international research team has identified very rare and previously unseen HIV variations in 17 Rwandan HIV patients who have lived for more than 12 years with the infection.
The variations could weaken the virus or may have been evolved by the virus to adapt to a strong immune system response, but more research is needed to answer this question, Dr. Francois Roman of CRP-Sante in Luxembourg told Reuters Health. He presented his findings here Sunday at the Interscience Conference on Antimicrobial Agents and Chemotherapy.
Roman and his colleagues sequenced a specific part of the envelope enclosing the human immunodeficiency virus known as the V3 loop. The envelope, he noted, is the first part of the virus to interact with a cell, and the V3 loop--which has tremendous genetic variability--helps determine which cells the virus will infect. The V3 loop also helps neutralize the immune response to HIV.
The 17 patients had all lived for more than 12 years with the virus, and had ``very good immune parameters,'' Roman said. Their clinical stage of HIV infection was relatively low, and all had CD4 T cell counts higher than 500, which shows their immune systems were still functioning well.
The genetic sequence of the patients' V3 loops was compared with the Los Alamos HIV database, which contains more than 500 HIV gene sequences. Roman and colleagues found that the Rwandan patients had V3-loop variants that were either not present at all in the Los Alamos database or were seen in less than 0.5% of strains in the database.
One of the very rare variants was seen in three of the Rwandan patients and another in two of the patients. Two of the patients shared one of the previously unseen variants.
Roman said that while it is not yet clear what role the V3-loop variants play in HIV infection, he and his colleagues hypothesize that they may somehow weaken the virus. He also noted that the patients may have had a very strong immune response to infection, which could force the virus to evolve in a certain way.
Roman said he and his colleagues have checked the V3-loop proteins of another group of Rwandan HIV patients who were not long-term survivors, and found they did not have the variants.
The next step, Roman said, will be to look for these V3 variants in groups of HIV patients from a different geographical area, and to test the ability of HIV with these particular mutations to infect cells in the laboratory.

This Site Served by TheHostPros