For the first time, investigators in the Division of Infectious Diseases at the University of North Carolina School of Medicine have determined how antiretroviral therapy (ART) affects the way HIV disseminates and establishes infection in the female reproductive tract. These observations have significant implications for future HIV prevention, vaccine and cure studies. A recent HIV prevention clinical trial demonstrated 93 percent protection against secondary heterosexual transmission when infected partners received early ART. Vaginal transmission accounts for the majority of new HIV infections worldwide. Globally, 35 million people are living with HIV and 2.1 million are newly infected each year. These findings were published in the Journal of Clinical Investigation.
"Surprisingly, it does not matter how a woman is exposed to HIV -- vaginally, rectally, etc. -- the virus goes very quickly to the female reproductive tract," said J. Victor Garcia, PhD, study co-author, and a professor of medicine in the Center for AIDS Research, the Institute for Global Health & Infectious Diseases, and the Division of Infectious Diseases at UNC. "Your body's CD4 T cells, which are the cells HIV infects, also migrate to the female reproductive tract shortly after exposure. It is like putting more kindling on a smoldering fire."
Using humanized mouse models, Garcia and his team also noticed that CD8 T cells, the cells in the body that fight infection, are delayed in getting to the female reproductive tract. This delay allows HIV to establish itself not only in the female reproductive tract, but also in cervicovaginal secretions.
"Your CD8 T cells, which are supposed to protect you, are not arriving in the female reproductive tract in time," said Garcia. "When we think about potential vaccines against HIV, this is important information to have."
The original study (DOI: 10.1172/JCI64212) is available for free from The Journal of Clinical Investigation.
(Score: 0) by Anonymous Coward on Wednesday February 10 2016, @01:47PM
"Surprisingly, it does not matter how a woman is exposed to HIV -- vaginally, rectally, etc. -- the virus goes very quickly to the female reproductive tract"
The more I hear about HIV the odder it gets. First, it is nearly impossible to transmit sexually[1], second most infections appear to start from a single virus,[2] despite the huge genetic diversity of intrapatient HIV that supposedly makes it hard to treat[3]. And now this business about homing to the reproductive tract. This just doesnt sound like a virus... it sounds like an entire cell gets transmitted.
[1] http://m.jid.oxfordjournals.org/content/191/9/1403.full [oxfordjournals.org]
[2] http://www.ncbi.nlm.nih.gov/m/pubmed/18490657/ [nih.gov]
[3] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2614444/ [nih.gov]
(Score: 0) by Anonymous Coward on Wednesday February 10 2016, @01:54PM
I forgot to mention, this virus is so difficult to transmit even between humans yet has also jumped species from simians half a dozen times in the last few decades, but never did it before. Its all extremely odd.
http://evolution.berkeley.edu/evolibrary/news/081101_hivorigins [berkeley.edu]
(Score: 0) by Anonymous Coward on Wednesday February 10 2016, @02:11PM
Previous transmission did not cause an epidemic, but that doesn't mean there weren't unlucky individuals who got infected. The human world has also changed a lot since SIV first recombined in a chimp.
(Score: 0) by Anonymous Coward on Wednesday February 10 2016, @02:49PM
OP AC here. I missed the update at the bottom:
http://evolution.berkeley.edu/evolibrary/news/081101_hivorigins [berkeley.edu]
This is apparently a very common event for an inter-species transmission, the opposite of what we would expect due to the difficulty of human-human transmission.
(Score: 0) by Anonymous Coward on Wednesday February 10 2016, @02:07PM
1: 1-3% chance of infection per sexual act is not "nearly impossible".
2: HIV genetic diversity increases after the initial infection because it mutates rapidly.
3: This study shows that the HIV RNA positive cells from the vaginal secretions could not transmit the virus after therapy. HIV infects cells and can "hitch a ride" to lymph nodes via dendritic cells but it is unlikely something as large as a cell would productively cross the mucosal barrier of another person.
(Score: 0) by Anonymous Coward on Wednesday February 10 2016, @02:28PM
Where did you get these numbers? Not from my ref 1, that reports rates 10x lower. Here is another reporting ~1 transmission per 100 person-years amongst couples: http://www.ncbi.nlm.nih.gov/pubmed/21767103 [nih.gov]
For a virus, this is really, really difficult to transmit.
Sure, so how is it that a new infection seems to be caused by a *single* founder virus. How is it that only that one virus gets transmitted with no others?
Where in the paper is this experiment? They don't look at transmission, they look at amount of HIV RNA. As noted above, it apparently is usual for only a *single* virus to transmit HIV so the connection between RNA levels and transmission is not going to be simple.
(Score: 2) by takyon on Wednesday February 10 2016, @02:47PM
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 0) by Anonymous Coward on Wednesday February 10 2016, @03:08PM
Not sure about your point. I do note that in this paper they collected HIV RNA plasma data but don't report it! If the treatment worked by reducing HIV RNA then we should see reduced transmission and reduced plasma HIV in the same people. This is crucial, so why don't they report that data?
(Score: 2) by wonkey_monkey on Wednesday February 10 2016, @04:03PM
Tract.
That is all.
systemd is Roko's Basilisk
(Score: 2, Funny) by Anonymous Coward on Wednesday February 10 2016, @04:24PM
Chick Tract.
(Score: 2) by wonkey_monkey on Wednesday February 10 2016, @04:29PM
Ow! They should call me Mario cos I just got 1Up'd!
systemd is Roko's Basilisk
(Score: 3, Funny) by DeathMonkey on Wednesday February 10 2016, @07:41PM
Using humanized mouse models, Garcia and his team...
Can't help but picture an HIV infected Mickey Mouse.
Serves you right for raping the public domain!
Also, I think the public domain needs to start making a few calls...