The research took advantage of a method known as ultradeep sequencing, which provides hundreds or thousands of glimpses of a single genetic change, compared to approximately 50 or so looks using conventional methods.
"This new technology is very exciting," said Lee. "It allows us to look at the earliest stages of infection in more depth than we could otherwise, and to quantify exactly what is going on in the body. If we can understand it more completely, we can fine-tune vaccines under development."
As expected, the team found that immune cells known as CD8+ T-lymphocytes, also known as cytotoxic T cells, are a powerful force in the life of SIV when it first causes infection. While scientists have known that the CD8 attack on the virus is strong, the latest work quantifies the body's response. They found that the original portions of the virus degrade 400 times faster in response to CD8 cells than they would have if those cells weren't a factor what scientists call significant "selective pressure" on the virus.
The team also found that SIV creates such mutants in response to the assault by CD8 cells at about the same rate as HIV does.
But the most striking finding is that the original viral genetic sequences are still present in the body months after the initial infection, at a time that scientists call the "viral set point," which occurs about two to five months after infection. It's a signal of just how difficult it is for the body to eradicate HIV from the body key portions of the virus have managed to survive des
|Contact: Tom Rickey|
University of Rochester Medical Center