Interview: HIV and AIDS Research

Today we have another interview. This time, I sat down to talk to an AIDS researcher to discuss… well, HIV and AIDS. Not much more of an intro is needed, so let’s jump into it.

ChrisDantes.com
First off, thanks for agreeing to do this interview. I don’t know much about the topic so I look forward to learning.

Melissa
No problem! Happy to do it.

ChrisDantes.com
What are your qualifications and education?

Melissa
Well, I started with a Bachelor of Science, specializing in Microbiology. Now, I’m in my last year of a PhD in Medical Microbiology/Infectious Disease, specializing in human immunology and HIV.

ChrisDantes.com
Ok. What are the differences between HIV and AIDS?

Melissa
HIV is the virus (Human Immunodeficiency Virus) that causes the condition of AIDS (Acquired Immune Deficiency Syndrome). So, as such, a person is first infected with HIV, and then over time, as their immune system is damaged and breaks down, they develop the end stage disease of AIDS.

ChrisDantes.com
When someone dies of HIV or AIDS, it’s because they get an infection or something, and their immune system is compromised, so they can’t fight back, right?

Melissa
Yes, that’s right. The virus essentially breaks down the immune system, so that a typical infection that a healthy person could easily fight off (a cold, flu, pneumonia, etc.) is able to cause serious damage and sometimes death.

ChrisDantes.com
Do we know how that happens? Does it limit the creation of white blood cells?

Melissa
Sort of. The reason HIV is so destructive to the immune system is that it preferentially infects a specific type of cell, called a CD4+ T cell. These cells in particular are a very important part of a functional immune system, so, as HIV infects them, they begin to die off quickly. As they die, the body is simply unable to fight off other “normal” infections, because this particular cell type has been depleted.

ChrisDantes.com
I’ve heard “T cell counts” mentioned. What does that mean?

Melissa
That’s exactly what I was just talking about! When people say “T cell counts”, they’re referring to the number of CD4+ T cells in a person’s blood. This is a classic measure of how healthy an HIV+ person is. For example, a “healthy” person would have typically between 500 and 1500 CD4+ T cells per cubic mL of blood; a person who has reached a clinical diagnosis of AIDS will have CD4+ T cell counts below 200.

ChrisDantes.com
So the higher the count, the better the immune response?

Melissa
Exactly. As the T cell count drops, the person is typically less able to fight off infections and more likely to become seriously ill.

ChrisDantes.com
What about treatments? I’ve heard that the earlier the diagnosis, the more quickly treatment can begin, the greater chance of survival. Is that correct?

Melissa
Yes, there is definitely some truth to that. Even if diagnosis is early, we still don’t typically treat people until their T cell counts drop below 350, because the drugs can have some pretty harsh side effects. But we know now that people are less likely to recover if treatment is started late (T cell counts below 200, for example).

ChrisDantes.com
What’s the typical treatment currently? Antivirals?

Melissa
Yes, there are something like 30 different antiretroviral drugs on the market, and typically people take a combination of them for the best impact. These days, if people are started on therapy as soon as their T cells begin to drop, they can live in “relative health” for decades; a huge improvement from how it used to be. The drugs need to be taken regularly and the patients monitored closely though, since the virus can mutate and cause drug resistance, and like I said before, for management of side effects.

ChrisDantes.com
Ok. On the research side, what are you working on?

Melissa
I work with a group who studies HIV transmission among a group of female sex workers in Kenya. Most of my group is interested in the women who are continuously exposed to HIV but do not become infected (~10% of them), but my work in particular focuses on HIV+ women. More specifically, I’m studying a different kind of T cell called the CD8+ T cell, which is responsible for attacking the virus. I’m trying to understand exactly what type of CD8+ T cell is best at killing the virus when it is encountered.

ChrisDantes.com
Interesting. How do you test for that? Maybe that’s not the right way of asking.

Melissa
Haha. Well it’s a complicated question but I know what you mean. Basically what we do is get blood samples from the HIV+ women, and isolate their immune cells. With those cells, we can do all kinds of different assays and tests in the lab. I use a technique called flow cytometry for most of my work, which is a fancy assay on an even fancier machine that basically uses lasers to look at the cells and tells you what they “look” like: what kind of antiviral compounds they secrete, what sort of functions they have, etc.

ChrisDantes.com
So what is your goal?

Melissa
To graduate 🙂

No, but really, the thing about HIV research is it’s just so complex. My entire PhD is such a small piece of the puzzle. So I guess my overall goal is to contribute my little bit of knowledge to this field, learn as much as I can in the process, and hopefully at the end be in a position to use my knowledge to do what I can to move this field forward.

ChrisDantes.com
Makes sense. Do you think we will find a cure in our lifetime?

Melissa
It’s difficult to say because HIV is really a tricky infection, but I think we’ve made a lot of really good progress recently. We’re starting to understand some things about how the virus hides in the body that we never knew before, which I think is key to figuring out how to get rid of it completely. So, yes I think it’s certainly possible if the level of interest and funding stays high in the field.

ChrisDantes.com
What do you mean when you say it “hides in the body”?

Melissa
One of the biggest challenges with HIV is it can form what we call “reservoirs” in the body, where it can hide in your cells, but more or less lay dormant, not reproducing, not killing cells, just hanging out. This makes it almost impossible for the immune system or antiviral drugs to detect, impossible for even our TESTS to detect. Then, at some point in the future, it can “activate” again, begin replicating, killing cells, etc.

ChrisDantes.com
Creepy. Do we have any idea what activates it?

Melissa
That’s a really interesting question, actually. We really aren’t sure. It’s possible that it may reactivate naturally if the immune system is challenged by another infection, and the T cells it is hiding in are essentially “turned on”, causing the virus to start replicating within those cells. But this is a really important question right now, because if we can figure out how to trigger the latent virus to activate, that’s the only way we’ll be able to completely eradicate it from the body.

ChrisDantes.com
This is so fascinating to me. Are there any other illnesses that react in a similar way to HIV or AIDS? Or are you kind of dealing with an illness that is in a category of it’s own?

Melissa
I really think HIV is one of a kind. I mean there are a lot of chronic infections out there, like hepatitis for example. But HIV is really unique in that it basically hijacks the immune system in order to spread, and in doing so, completely destroys it. No other infection does that to nearly the same extent, which is why HIV has been so difficult to control.

ChrisDantes.com
Do you worry about resistant strains? Like even if we did find a cure, eventually AIDS would evolve a tolerance, so our cure would be ineffective.

Melissa
Resistance is always a concern with HIV. It mutates incredibly quickly, so we always need to consider that when conceptualizing a treatment, cure, or vaccine. For a vaccine, for example, we’d need to create something that is effective against a WIDE variety of strains of HIV. When it comes to a cure, it’s a bit easier, since, even though the virus mutates quickly, it has a lot of “conserved” regions that don’t really change that are pretty easy to target.

ChrisDantes.com
Whoa. I hadn’t even thought about a vaccine. How many strains are there? I remember a TV show… CSI or something… that said that as soon as a person is infected, the strain changes. So basically, everyone who is infected has their own strain. Is that true?

Melissa
I don’t think I could properly innumerate how many strains there are! But yes what you’ve said is more or less true. When HIV is so error prone that at least one mutation is likely to occur each time the virus replicates. Of course, many of the resulting viruses will be non-functional, but each person who has HIV likely has several different strains circulating within them at once. Keep in mind many of these strains are very, very similar to one another, but there are MANY different strains.

ChrisDantes.com
That’s terrifying. Do we know how HIV or AIDS started? Besides God hating homosexuals.

Melissa
Haha! Yeah. God didn’t think that through very carefully, since most infections are in heterosexuals now… OOPS!!!

We don’t know for certain how it started, but it’s likely it came about somewhere in west Africa during the early 1900’s. HIV is very similar genetically to a simian infection, so it’s thought that an accident during hunting of bush meat probably led to the first infection.

ChrisDantes.com
Ok. That’s brings up two things. Transmission, and risk factors. Let’s start with transmission, and then I’ll totally forget to mention risk factors. How is it transmitted? I know it’s a blood disease, so any time an infected person’s blood gets into your blood stream, infection is possible. Is that correct?

Melissa
Yes that’s right! The virus is found primarily in the blood and genital secretions, so the most common methods of transmission are through blood (transfusions, sharing of needles between drug users, from mother to child during birth) or sexual contact.

ChrisDantes.com
What about risk factors? Ha! I remembered. I remember hearing that the most at risk people were IV (intravenous) drug users, and unprotected sex.

Melissa
Haha. Well done! Yes that’s about right. Injection drug users are at high risk, as are men who have sex with men, and commercial sex workers in particular. But anyone who has unprotected sex with someone infected is certainly at risk.

ChrisDantes.com
HIV and AIDS causes a HUGE fear among people, rightfully so, but I think it has a bit of a stigma to it. Like it started out as GRID (Gay Related Immune Deficiency) because it was thought that only gay men could get it. Then they noticed other people could get it too, so they went to the opposite direction and thought if you so much as look at someone infected, you could get it.

Melissa
Oh, yeah. There’s a ton of stigma associated with HIV. Luckily the association with homosexuality has finally started to decline, as we see it spreading so quickly through the heterosexual population, but there is still a lot of wrong information out there… That you can get infected by kissing or sharing drinks with someone who has it, which is simply not true. In other parts of the world where rates are really high, the stigma is even worse. Families will refuse autopsies on loved ones who have died because they don’t want anyone to know they died of AIDS.

ChrisDantes.com
Sad. So besides condoms and clean (new) needles, what else can people do to protect themselves from infection?

Melissa
That’s pretty much all you can do to protect yourself. Of course it’s important to know the status and sexual history of your partners. And more importantly, it’s crucial to get yourself tested regularly. If you have been infected, your best chance of living a relatively normal life, and of not passing the infection on to others, is to know you have it.

ChrisDantes.com
I think the National Institute of Health in the US recommends getting tested every six months, even if you’re healthy. It’s a simple blood draw and then they do… magic or something and tell you if you have it or not. Actually, I think if they get a positive, they ask for another test just to be sure.

Melissa
Yep, that sounds about right. They recommend getting tested every 6 months as it typically takes 3-6 months from the time you’re infected for it to show up on our tests. And they always do a confirmatory test if the initial one comes up positive, since being HIV+ is kind of a big deal. They have a relatively new test on the market now that gives you results from a drop of blood within about 10 minutes. I’ve had it done before. It’s pretty neat!

ChrisDantes.com
How do the tests work? I mean, do the HIV or AIDS cells show up under a microscope? Or do they count the T cells?

Melissa
HIV is too small to be seen under a tradition microscope, so the tests we do usually look for antibodies. When a person is infected with the virus, their body will react to it and start producing antibodies against it. Otherwise, we can also do tests looking for HIV proteins directly. Typically both these methods are used to confirm an infection, and after an infection has been confirmed, THEN we’ll test for T cell counts to see how healthy the HIV+ person is.

ChrisDantes.com
Ah. So what can we as the little people do to help you and other researchers find a treatment or cure?

Melissa
I think the best thing people can do to help this cause is to take care of themselves. Learn about the virus. Use protection. Get tested. Encourage your partners to get tested. The best defence against HIV remains not getting infected in the first place.

ChrisDantes.com
Ok. Back to your particular research, why are women less likely to get infected? Is HIV afraid of vaginas?

Melissa
Haha! I wish! It’s not so much that women are less likely to get infected, in fact, globally, women make up a higher percentage of infected people than men, but that the route of infection is very important. Anal sex* is most likely to lead to transmission, which is why it popped up initially in men who have sex with men. I think we hear about infected women less often just because men who have sex with men and injection drug users are the most common risk groups in North America and Europe, while the vast majority of women who are infected are found in sub-Saharan Africa.

*Note, the reason anal sex is more likely to lead to transmission that vaginal sex, is that the membranes in the anus are not designed for penetration. They can rip or tear allowing the infection easy access to the blood stream.

ChrisDantes.com
Plus as you pointed out earlier, the stigma prevents people from knowing they are infected. And of course condom usage is very low in Africa.

Melissa
Yes, those are both really big issues. Added to the fact that commercial sex work is such a big industry, and education about the infection so low, and you’ve got a perfect storm for HIV.

ChrisDantes.com
Well I’m out of questions. Is there anything you’d like to mention or tell people?

Melissa
Haha. Well I think you managed to cover all the important bits. I’d just like to reiterate again how important it is to get tested. Knowing your status is so important, especially since most of us live in parts of the world where we rarely think about HIV as something that could affect us. So, that’s my point: GET TESTED FFS.

ChrisDantes.com
And even if you don’t have health insurance, places like Planned Parenthood offer the tests for little to no costs.

Melissa
Yes, that’s a great point. There are lots of places you can go to to get access to testing and it’s really one of the best things you can do for your own health.

ChrisDantes.com
Thank you so much for spreading the knowledge and keep up the science.

Melissa
I’m always happy to hear myself talk. Thanks for asking me to chat!