Bizarrely, it could lead to therapies which turn off the immune response to HIV rather than try to boost it.
Sooty mangabey monkeys do not become ill when infected, but until now researchers did not have much idea why.
However, a team of experts from the University of Texas Southwestern Medical Center in Dallas, and Emory University believe they have found two key differences in the way that the monkeys' immune systems deal with the virus.
The monkeys appear able to generate only a low-level immune system response when confronted with an infection of simian immunodeficiency virus (SIV).
They can also keep their ability to make T cells - the kind of immune cells depleted in humans with HIV.
New insight into the mechanisms that control the number of virus particles in the blood of sooty mangabeys naturally infected with SIVsmm, the strain of SIV that naturally infects sooty mangabeys, has now been provided by a team of researchers from the University of Pennsylvania, Philadelphia, and Emory University, Atlanta.
HIV and SIV infect immune cells known as CD4+ T cells. So, the authors set out to determine how CD4+ T cells affected the number of virus particles in the blood of sooty mangabeys naturally infected with SIVsmm -- did they provide immune control of the number of virus particles or did they simply provide a place to live a replicate.
The number of SIVsmm particles in the blood of naturally infected sooty mangabeys decreased when the monkeys were depleted of CD4+ T cells and then increased again as the number of proliferating CD4+ T cells rebounded.
So, it was concluded that availability of proliferating CD4+ T cells is a key determinant of how many SIVsmm particles can be detected in the blood of naturally infected sooty mangabeys, rather than CD4+ T cells providing immune control of the virus.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.