Immune exhaustion in HIV infection

May 6, 2008

As HIV disease progresses in a person infected with the HIV virus, a group of cells in the immune system, the CD8+ T lymphocytes, become “exhausted,” losing many of their abilities to kill other cells infected by the virus. For many years scientists have debated whether this exhaustion of CD8+ T cells is the cause, or the consequence, of persistence of the HIV virus. In a study published this week in PLoS Medicine, Marcus Altfeld and colleagues studied the immune response over time amongst 18 individuals who had very recently become infected with HIV.

These researchers found that the presence of high amounts of HIV in the blood seemed to cause CD8+ T cell exhaustion; when antigen was reduced, either as a result of treatment with antiretroviral drugs, or evolution of viral epitopes to avoid recognition by CD8+ T cells, these epitope-specific CD8+ T cells recovered some of their original functions. These findings suggest that CD8+ T cell exhaustion is the consequence, rather than the cause, of persistent replication of HIV.

In a related article, Sarah Rowland-Jones and Thushan de Silva (from the Medical Research Council in Gambia), who were not involved in the study, discuss approaches to treat HIV efficiently by suppressing the viral load early in infection aimed at preserving HIV-1-specific immune function. They evaluate whether such strategies are likely to be practical.

Citation: Streeck H, Brumme ZL, Anastario M, Cohen KW, Jolin JS, et al. (2008) Antigen load and viral sequence diversification determine the functional profile of HIV-1– specific CD8þ T cells. PLoS Med 5(5):e100.

Source: Public Library of Science

Explore further: The difficult Way to HIV Vaccine

Related Stories

The difficult Way to HIV Vaccine

September 16, 2009

T cells are key players in the immune response to HIV, which are able to delete infected cells. This capacity is used for vaccine development against HIV. “To date however, success of this strategy remains elusive. Our ...

Extraordinary immune cells may hold the key to managing HIV

December 4, 2008

People who manage to control HIV on their own are providing scientists with valuable information about how the immune system eliminates virus-infected cells. A new study, published in the December 4th issue of Immunity, a ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.