Breakthrough study of 2011 and the tools for curbing HIV

The journal Science has named the HPTN 052 clinical trial, a study looking at the ability of antiretroviral medication to prevent HIV transmission, as the 2011 Breakthrough of the Year:

Led by study chair Myron Cohen, M.D., director of the Institute for Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill, HPTN 052 began in 2005 and enrolled 1,763 heterosexual couples in Botswana, Brazil, India, Kenya, Malawi, South Africa, Thailand, the United States and Zimbabwe. Each couple included one partner with HIV infection. The investigators randomly assigned each couple to either one of two study groups. In the first group, the HIV-infected partner immediately began taking a combination of three antiretroviral drugs. The participants infected with HIV were extensively counseled on the need to consistently take the medications as directed. Outstanding compliance resulted in the nearly complete suppression of HIV in the blood (viral load) of the treated study participants in group one.

In the second group (the deferred group), the HIV-infected partners began antiretroviral therapy when their CD4+ T-cell levels—a key measure of immune system health—fell below 250 cells per cubic millimeter or an AIDS-related event occurred. The HIV-infected participants also were counseled on the need to strictly adhere to the treatment regimen.

It was found that those taking the medication while their immune system was still highly healthy were 96% less likely to transmit HIV to their partners. This result was so stupendous that, even though the trial is still ongoing, an early public release of the findings was ordered. It is important that people know how to best combat transmission. That spread of information is what is needed to prevent the spread of infection:

“On its own, treatment as prevention is not going to solve the global HIV/AIDS problem,” said Dr. Fauci. “Yet when used in combination with other HIV prevention methods—such as knowing one’s HIV status through routine testing, proper and consistent condom use, behavioral modification, needle and syringe exchange programs for injection drug users, voluntary, medically supervised adult male circumcision, preventing mother-to-child transmission, and, under some circumstances, antiretroviral use among HIV-negative individuals—we now have a remarkable collection of public health tools that can make a significant impact on the HIV/AIDS pandemic.”

“Scale-up of these proven prevention methods combined with continued research toward a preventive HIV vaccine and female-controlled HIV prevention tools places us on a path to achieving something previously unimaginable: an AIDS-free generation,” Dr. Fauci added.

I added the emphasis to the above excerpt because I am reminded of the utter irresponsibility displayed by PZ Myers on this issue in the past. While I still very much like what the guy has to say on many subjects, he was dead wrong to dismiss any one of the listed tools. In this case, he specifically dismissed the notion that there is any evidence whatsoever that circumcision has any impact on HIV infection rates. As I’ve documented elsewhere, he is absolutely wrong on the facts. That evidence does exist and it is important that it is known. That is why Dr. Fauci noted it amongst all the other ways we must use to combat this disease. HIV/AIDS is one of the most serious epidemics facing the developing world today; no one should be proud to exacerbate the problem, especially when the motivation is ideological in nature – we’re talking about god damned human lives here.

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HIV: It’s still all about shape

The last time I wrote about HIV, I made the point that biology is all about shape; keep that idea in mind and a lot of things will suddenly start making a lot of sense. In that instance, I was writing about antibodies that were able to nearly universally attack HIV based upon one particular location on the virus which did not change shape. In this post I want to talk about a new study concerning protein differences.

To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and analyzed the effects of individual amino acids within the classical HLA proteins

HIV controllers are just what you probably think they are: they are people whose bodies are able to control the impact of HIV. They maintain healthy levels of helper T Cells. Progressors, on the other hand, are people who follow the expected course after they contract HIV. In this study, a large group of controllers were taken and had their genomes compared to progressor genomes. Researchers found more than 300 (313, to be exact) SNPs on the chromosome 6 that separated these two groups.

This is a pretty specific area with a small amount of difference. In fact, on the HLA-B protein, a difference of just 5 amino acids makes all the difference in a single groove. It appears as though this is one of the most important differences between controllers and progressors, constituting a significant region which enables the immune system to control and limit the proliferation of HIV. The amino acid sequence changes the shape of the groove in controllers as compared to progressors. This change protects the controller against HIV and its deadly consequences.

Precisely how this change in shape keeps HIV from turning into AIDS has not yet been made clear, but it is very promising. Given the current state of research, I’m willing to predict we’ll see a cure for HIV before we see a cure for cancer.

The fight against HIV

In biology, it’s all about shape. Enzymes, proteins, antibodies, blood vessels, cells, everything. They work best when they fit best or match in shape best. That’s why two new HIV antibodies have such potential.

Scientists report they’ve discovered possible new weapons in the war against HIV: antibody “soldiers” in the immune system that might prevent the AIDS virus from invading human cells.

According to the researchers, these newly found antibodies connect with and neutralize more than 90 percent of a group of HIV-1 strains, involving all major genetic subtypes of the virus.

That breadth of activity could potentially move research closer toward development of an HIV vaccine, although that goal still remains years away, at best, experts say.

HIV molecules evolve at a rapid pace. This makes it nearly impossible to produce antibodies at rates and in quantities sufficient to combat the disease on a long-term basis. However, there is one part of an HIV virus which remains virtually unchanged. This is important because it means there is a site with a consistent shape on the virus. That’s where these antibodies are being directed, thus offering a potentially powerful new tool in the fight against HIV.