Washington: Scientists may have found an answer to why some monkeys don``t develop AIDS, despite being infected by the simian immunodeficiency virus (SIV), the monkey equivalent of HIV.
"It is thought that they``ve met some sort of equilibrium where the virus persists but without making the host sick," ABC Science quoted him, as saying. Davenport added: "It remains an open question; the mechanism by which these animals manage to remain healthy." He said five years ago, researchers found that the T cells in the natural hosts of SIV have lower "activation" than those in monkeys that get sick from the virus.Activation comprises proliferation of T cells that can occur in response to a virus, but can also occur in response to a drop in T cell numbers. When a virus like SIV infects and kills off T cells, this "homeostatic response" boosts the numbers of T cells again.But the more T cells are activated, the greater the risk of infection because the virus prefers to infect and kill activated T cells. Davenport``s colleagues in the US compared T cell activity in HIV-infected humans and SIV-infected monkeys.
The monkeys included the AIDS-susceptible Rhesus macaques and two AIDS-resistant monkey species - Sooty mangabeys and Mandrills.They discovered that in the human and Rhesus monkey, the homoeostatic response (T cell activation) was a lot higher than in the Sooty mangabeys and Mandrills. According to Davenport and colleagues, the AIDS-resistant monkeys are less affected by the virus because their immune system doesn``t "over-react" to the loss of T cells that takes place during infection.Whereas in the AIDS-susceptible species, higher activation of T cells can act to "fuel the fire" of infection by providing more proliferating cells for infection. ANI
Kejriwal asks TV anchor to tweak interview
Amar Singh, Jaya Prada join Ajit Singh`s RLD
Modi slams Nitish Kumar in Bihar rally
AAP leader Ashwin Upadhyay calls Arvind Kejriwal `CIA agent`