Researchers at massachusetts General Hospital (MGH), published a study-- HIV can mutate key proteins in order to hide from an immune attack. But once these mutations occur they persist.
When HIV attacks, the cell alerts the immune system by displaying viral protein fragments on the surface. This is a suicide signal to kill the infected cell. The immune response that is generated depends on the ability to recognise the displayed HIV fragment.
The study indicates that the virus can learn how to evade the immune response in one person, and that it retains this ability even after it is transmitted to the next person according to researchers.
When this happens, the immune sustem is forced to use a second-line attack strategy that was less effective in cintaining the virus in the patients studied. These studies, which were performed in HIV-infected mothers who transmitted virus to their infants, showed that the infected infants are less able to control the virus because of mutations that occured in the mothers.
The effects of these mutations were particularly apparent in the children since they inherit key elements of their immune systems from their parents, and thus there is a strong chance that they will be programmed to target the same regions that the mother targeted. In mothers in whom mutations has already arisen, the children could not target the virus effectively.