HIV immunity and other fun science

5 02 2009


First of all, one of the newest and most exciting studies at curing and preventing HIV permanently has begun today at UPenn (I believe).

From Wired (via TrevorHoppe, via Joe. My. God.):

Gene therapy that could immunize people against the most common type of HIV is ready to be tested on humans.

ruiting for the trial began Tuesday, and the first people to receive the experimental treatment will be HIV patients with drug-resistance problems.

“We do have good treatments for HIV. That has been one of the most successful stories of the last 20 years in medicine,” said Pablo Tebas, an infectious disease expert at the University of Pennsylvania.

“However, over time, if the medications are not taken properly, individuals develop resistance to the HIV treatments, so they tend to have more limited therapeutic options.”

Since the discovery that a small portion of people who are exposed to HIV do not get infected, scientists have been working to discover the secret to those people’s resistance and how to make others resistant as well.

It turns out that most people have a gene called CCR5, which makes them vulnerable to HIV infections. The naturally resistant people have mutant CCR5 genes that inhibit HIV.

Previously, scientists found that by cutting the CCR5 gene out of white blood cells involved in the immune response known as T-cells, they could protect a tube full of human cells from the virus. The gene editing technique relies on proteins called zinc finger nucleases that can delete any gene from a living cell.

In theory, zinc finger nucleases could give that immunity to anyone.

The procedure is simple: Take some healthy T-cells out of an HIV patient, clip out their CCR5 genes, grow more of these clipped T-cells in a dish, and then put them back in the patient.

“In this first study we will re-infuse approximately 10 billion of these cells back into the participants, and we will see if it is safe and if those cells inhibit HIV replication in vivo,” said Tebas. “We know they do in the test tube.”

I will buy dinner to the first person who can find out how the crazy right-wingers are going to turn this into a cloning, abortion, etc. argument. (The only argument I will not accept is this: AIDS cures people of they gay… I’m sure Fred Phelps has already said that enough, so let’s just let sleeping assholes lie.)

Second exciting bit of news, which should a lot for HIV-positive people’s sex lives, via Wisdom of Whores (a great book!!!), via Cuddling on the Wild Side:

Public health types are always agonising about oral sex. Should we say it’s dangerous or not? Now, Swedish researchers have shown that lots of oral sex with an HIV-infected partner may actually be protective against the virus.

The study, published in the (expensive, subscription only) AIDS journal and helpfully summarised by Aidsmap suggests that men who give lots of blow jobs to their HIV-positive partners develop antibodies specific to that partner’s virus, protecting themselves against infection. The more virus their partner has kicking around in their semen, the higher the concentration of specific antibodies, and the protection seems to last for quite a while too. None of the men became infected over the course of the study, even though their partners were not all on treatment.

I’ve never been one for warning people off oral sex — while it is not 100 percent risk free it’s almost always safer than any of the alternatives that provide as much fun. But I’d hate to lose my agonised public health type credentials entirely, so I’ll point out a caveat in this study. The couples who were recruited, an infected man with an uninfected partner, had to have been together for at least 6 months — beyond the most dangerous period for infection in most cases. Any guys who did get HIV through oral sex in that risky early part of their relationship wouldn’t be in the study, because they would no longer be in a “discordant” relationship.

I’ll say this about oral sex, as a “public health type:” the reason we agonize over oral sex is simple. Long again, when I worked at Planned Parenthood, my NP had an argument that I didn’t agree with at the time but one I get now: we shouldn’t cure HIV because there needs to be something we are scared of out there. With oral sex, though there are no conclusive proving transmissability via oral sex, and the cases are anecdotal and prove nothing, it would be irresponsible to say that “oral sex transmits HIV” because we’re pretty sure it doesn’t.

However, oral sex isn’t safe sex, it’s safer, yes, but that’s it. You can still get herpes, gonorrhea (common), chlamydia (rare), and syphilis pretty easily from unprotected oral sex (u/oSIC as I document it, verses u/arSIC or u/aiSIC or u/vSIC). But if you start telling people that you can’t get HIV from oral sex, then they start thinking it’s perfectly safe.

And, like Saddlebacking, people start thinking that it’s perfectly fine.

That said… this is really good news for serodiscordant couples and their sex lives, and ten times more relevant than serosorting.

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One response

5 02 2009
Dr Jared

this makes me a happy panda! 🙂

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