Monthly Archives: February 2013

Can Blood Transfusions Cure HIV?

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In a different take on health and HIV related questions, Gawker reader, Michael, asks the question, “can massive blood transfusions be used to treat HIV”?

THE QUESTION:

Is it possible to cure, or at a minimum delay the effects of, HIV by simultaneously drawing infected blood and transfusing in ‘clean’ blood into the patient? You would still have tainted blood in the system, but wouldn’t this turn the clock back a bit in regard to how much of the virus is in the person’s blood stream?”

Here’s what doctors say on EXTREME blood transfusions as a fix for HIV

Dinesh Raoassistant professor, David Geffen School of Medicine at UCLA:

Not a bad question actually. The issue is that the virus infects T cells and these reside both in the blood and in tissues, such as the lymph nodes and the gastrointestinal tract. So even if one were to entirely rid the blood of the virus (which would be really difficult to accomplish), there would be other sites such as those I mention that would still have “reservoirs” of virus. Add to this the difficulty and potential complications of doing the blood exchange, which is done for certain other conditions… And you have a sufficiently bad benefit/harm ratio to make the procedure untenable.

Michael SaagDirector, Center for AIDS Research, University of Alabama at Birmingham:

Evidence for most infectious disorders is detected in the blood. This does not mean that the blood is the location of the infection. In the case of HIV, most / all of the virus replication occurs in lymphoid tissue (gut, spleen, lymph nodes), NOT in the bloodstream. Blood is simply a place were we can readily detect it. And while blood can transmit HIV, it is because the virus is present in blood not because it is replicating there. Therefore, removing ‘infected’ blood and replacing it with ‘clean’ is like taking a cup of water from the ocean and then pouring in a cup of fresh water in the hopes you would make the ocean a very large freshwater lake!

Michael Polesassociate professor, NYU School of Medicine:

The short answer is that it wouldn’t work. HIV is a retrovirus and, as such, integrates it’s reverse transcribed DNA into the host cell genome. That DNA will sit dormant in a lymphocyte until the cell dies. as such, there will be plenty of cells that contain HIV DNA sitting around, not just in the blood stream, but in the tissues, most notably the intestines. Even if you could replace all of the peripheral blood through transfusion, additional lymphocytes would be in the tissues and would continue to produce virus, which would just infect the cells that you have transfused in.

Patrick Fogartyassistant professor of medicine, University of Pennsylvania:

I can think of a few reasons why the approach you mentioned would not work, including that HIV infection is not a process that is confined to the intravascular space (meaning inside the blood vessels). The tissue through which the infection gained access to the body (needle stick, mucous membrane) would be contaminated with virus as would the regional lymph nodes, which drain these tissues. So exchanging the blood volume wouldn’t purge the body of the virus.

Ian Frankprofessor of medicine and Director, Clinical Core, University of Pennsylvania Centre for AIDS Research:

There is no way to delay the effects of AIDS by removing infected blood and transfusing in uninfected blood. HIV replicates predominantly in a type of lymphocyte called a CD4+ T cell, or a helper T cell. About 2% of the CD4+ T cells in our bodies are circulating in the blood. The rest are in our intestines or in lymph nodes scattered around our body. Therefore, even if we could remove all of the HIV infected lymphocytes in our blood, the vast majority of the cells infected by HIV would not be removed, and HIV would still be reproducing in those cells.

Hope that is understandable. [Ed.: lol]

THE VERDICT: No, you can’t cure (or even ameliorate) HIV/ AIDS with blood transfusions, because the virus hangs out elsewhere in the body, and would just reinfect the new blood.

Original article via Gawker

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Discussion:

Have you read any interesting articles about measures to halt, or cure HIV/AIDS.  Why do you think the answer has baffled scientists for so long.  Do you think they’ll ever be a cure, or a vaccine for HIV, and when do you think HIV will begin to become part of history, rather than a current medical condition.  Comments are open for two weeks.

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Anti-HIV drug effort in South Africa yields dramatic results

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An intensive campaign to combat HIV/AIDS with costly antiretroviral drugs in rural South Africa has increased life expectancy by more than 11 years and significantly reduced the risk of infection for healthy individuals, according to new research.

The two studies, published Thursday in the journal Science, come as wealthy Western nations are debating how best to stretch limited AIDS funding at a time of economic stress.

With an annual price tag of $500 to $900 per patient, antiretroviral therapy programs have stirred frequent debate. Critics argue that adherence to the drug regimen is low and social stigma prevents some from seeking care until they are very ill and have infected others. Cheaper remedies, such as condom distribution, male circumcision and behavior modification, deserve more attention and funding, they say.

The new economic analysis of a $10.8-million campaign in KwaZulu-Natal province concluded that the drug scale-up there had been highly cost-effective.

The program was administered by nurses in rural health clinics in an impoverished region of about 100,000 people. Treatment consisted primarily of daily doses of antiretroviral therapy, or ART, drugs, which patients take every day for their entire lives. Patients picked up their medication at a rural clinic once a month.

In 2003, the year before the drugs were available, 29% of all residents were infected with HIV and half of all deaths there were caused by AIDS. Life expectancy in the region was just over 49 years.

By 2011, life expectancy had grown to 60 1/2 years — “the most rapid life expectancy gains observed in the history of public health,” said study senior author Till Barnighausen, a global health professor at the Harvard School of Public Health.

Based on that increase in longevity, researchers determined just how many years of life were effectively “gained” among residents as a result of ART intervention. They used that figure and the total expense of the program to calculate a cost-effectiveness ratio of $1,593 per life-year saved.

The World Health Organization considers medical intervention to be “highly cost-effective” if the cost per year of life saved is less than a nation’s per capita gross domestic product. The program’s ratio was well below South Africa’s 2011 per capita GDP of about $11,000.

“It’s really a slam dunk of an intervention,” said study leader Jacob Bor, a graduate student at Harvard. “These investments are worthwhile.”

The research team noted that the study period coincided with the arrival of electric power and clean water for area residents. But those alone could not explain the dramatic increase in longevity, they said.

“While mortality due to HIV declined precipitously, mortality due to other causes flat-lined,” Bor said. “These changes were almost certainly due to ART scale-up.”

In a second study from the same region, researchers followed nearly 17,000 healthy people from 2004 to 2011 to determine HIV infection rates in areas with active ART intervention programs.

Healthy individuals in those areas were 38% less likely to contract HIV than people in areas where ART drugs were not widely available, researchers found. People in extremely rural areas also fared better than those in more closely populated areas clustered around national roads.

Overall HIV prevalence increased 6% during the seven years of the study, probably because the antiretroviral drugs allowed people with the virus to live longer, according to the report.

It’s not clear how the results of the new study would translate to areas where stable, cohabiting couples were not the norm, said lead author Frank Tanser, an epidemiologist at the University of KwaZulu-Natal.

AIDS researchers who weren’t involved in the studies said they provide strong support for maintaining programs like the President’s Emergency Plan for AIDS Relief, begun by President George W. Bush in 2003.

“These papers present truly remarkable data,” said Dr. Douglas Richman, director of the Center for AIDS Research at UC San Diego.

Original article via Gawker

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It’s 2013, & HIV Positive Job Seekers are Humiliated by Job Centre Staff

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A HIV positive jobseeker has said he was left humiliated by staff at a Kent job centre.

Jayce Carberry said staff in Maidstone made him declare his condition within earshot of others, and told him he had to see a disability adviser.

He said an adviser also said he would seek legal advice about what contact Mr Carberry could have with other staff.  The government said jobseekers were asked if they had a condition which could affect certain jobs.

Former hairdresser Mr Carberry said he went to the job centre a few weeks ago to discuss his options.

‘That stigma’

He said he was not disabled, and the advisor asked if he could write his HIV status in his notes, he said. Mr Carberry said he did not want it mentioned.

“His [the adviser’s] reply was I’ll have to speak to my legal team to see if we have to disclose your HIV status to any members of the staff you come into contact with in this building,” Mr Carberry said.

“Obviously I was a bit speechless.

“For somebody to make a comment like that, it just takes you all the way back to the beginning and your self-esteem is shattered, you go back to feeling ashamed.

“You’re subjected to that stigma and it’s really upsetting.”

Equalities Minister Helen Grant has written to the job centre
Equalities Minister Helen Grant, Mr Carberry’s MP, said she had written to the job centre and to Work and Pensions Secretary Iain Duncan Smith to raise her concerns.

Ms Grant, Conservative MP for Maidstone and The Weal, said: “It’s absolutely right that if people like Jayce do what they’ve done – go out, try to get work – that they should be given all the help and support that they need and deserve and at the same time, they must be treated with absolute dignity and respect.”

The Department for Work and Pensions, which speaks for job centres, said people did not officially have to declare medical conditions when applying for Jobseeker’s Allowance.

Original Article via BBC News

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Discussion:

What are your experiences when seeking work?  Have you ever had to disclose your status unwillingly?  Does HIV status even matter when seeking work (as opposed to starting work) and do you feel you should disclose to staff at Job Centres.

HIV positive patients fail to disclose their infection to NHS staff

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A significant proportion of HIV positive patients may not be disclosing their infection to NHS staff, when turning up for treatment at sexual health clinics.

This is the finding suggested by preliminary research published online in the journal Sexually Transmitted Infections.

If the findings reflect a national trend, this could have implications for the true prevalence of undiagnosed HIV infection in the population, which is based on the numbers of “undiagnosed” patients at sexual health clinics, say the authors.

Currently, it is estimated that around one in four people in the UK who is HIV positive doesn’t know they’re infected with the virus.

The estimate is based on several sources of data, including the GUMAnon Survey, which routinely looks for HIV infection in blood samples taken from patients to test for syphilis at one of 16 participating sexual health clinics across the UK.

The results are then matched with the individual’s diagnostic status—whether they had been diagnosed before their arrival at the clinic, or were diagnosed at their clinic visit, or left the clinic “unaware” of their HIV status.

It is thought that a proportion of patients who do know their HIV status nevertheless choose not to reveal it to NHS staff when attending for services elsewhere.

To test this theory, the researchers analysed all HIV positive samples from one participating GUMAnon clinic in London in 2009 for the presence of very low viral loads— a hallmark of successful drug treatment—and various antiretroviral drugs.

Of the 130 samples which matched clinic records, 28 were from patients who were not known to be HIV positive before their arrival at clinic. Ten had been tested for HIV at their clinic visit.

The remaining 18 did not have a test at the clinic, and were therefore classified as undiagnosed. Yet almost three out of four (72%) of these samples had very low viral loads, indicative of successful drug treatment.

Only eight samples were of sufficient volume to be able to officially test for antiretroviral drugs, but evidence of HIV treatment was found in all of them.

“This is the first published objective evidence that non-disclosure of HIV status as a phenomenon exists in patients attending [sexual health] clinics in the UK,” write the authors.

“Given the high proportion of individuals classified within this study as [non-disclosing], the extent to which these findings can be extrapolated to other clinics, and the degree to which they may influence estimates of the proportion of undiagnosed HIV in the community, warrants further study,” they conclude.

The reasons why they don’t come clean(sic) about their HIV status may be that they don’t want to be “judged,” given that they have come to the clinic with another infection, which implies they are indulging in risky sexual behaviour, suggests lead author Dr Ann Sullivan of London’s Chelsea and Westminster Hospital NHS Foundation Trust.

But by not revealing their HIV status, they could be missing out on the chance to be treated more holistically and discuss other aspects of their health which might be affected by HIV, she says.

Original Article via Onmedica, taking medical information further.

DISCUSSION:

The comment by Ann (above) implies NHS staff are predisposed with attitudes toward sex.  Especially when using phrases like “when they don’t come clean” – However, NHS staff; particularly those within genitourinary medicine should not assume those who wish to have a HIV test participate in “risky sexual behaviour” as for a lot of people, HIV infection can simply occur when the HIV status of a sexual partner is positive, but not known and undiagnosed, then innocently passed to another (which is why is it recommended that condoms are used if the HIV status of the other person is unknown.

Do you have an opinion on this? – Let us know in the comments below.

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Happy Valentines Day!!

Gender Symbols

Each year, on 14th February around the world, flowers, chocolates and gifts are exchanged between loved ones, all in the name of St. Valentine.

Valentine greetings were popular as far back as the Middle Ages, though written Valentine’s didn’t begin to appear until after 1400. The oldest known valentine still in existence today was a poem written in 1415 by Charles, Duke of Orleans, to his wife while he was imprisoned in the Tower of London following his capture at the Battle of Agincourt. (The greeting is now part of the manuscript collection of the British Library in London).  Several years later, it is believed that King Henry V hired a writer named John Lydgate to compose a valentine note to Catherine of Valois.

By the middle of the 18th century, it was common for friends and lovers of all social classes to exchange small tokens of affection or handwritten notes, and by 1900 printed cards began to replace written letters due to improvements in printing technology. Ready-made cards were an easy way for people to express their emotions in a time when direct expression of one’s feelings was discouraged. Cheaper postage rates also contributed to an increase in the popularity of sending Valentine’s Day greetings.

Today, according to the Greeting Card Association, an estimated 1 billion Valentine’s Day cards are sent each year, making Valentine’s Day the second largest card-sending holiday of the year. (Next to Christmas with 2.6 cards are sent for Christmas).

Today, alongside traditional paper based cards, digital eCards are sent, (the first ‘Electronic Postcard’ was created and sent in 1994 by Judith Donath of MIT Media Lab) and since that time, a large variety of websites offer similar services – to share and send ecards to loved ones at times of celebration.

LASS are no different, and we offer you the following video to share with your loved ones. As a sexual health charity, we obviously like to talk about sex and encourage people to enjoy sex responsibility, so what better time to release a cheeky video than Valentine’s Day?

Please share our video with your valentine (and your friends)!  We wish you all a very happy Valentine’s day or evening, (Whatever you get up to) and we hope our cheeky message will remind you to have a good time, and remember to be safe while you’re having it 😉

Tanya Goodwin created this concept video with animation by Richie Phillips at Seed Creativity.

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Why are we afraid to get tested for HIV?

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For some people the idea of being tested for HIV is as simple as making a note in a calendar, an entry which sits comfortably beneath a dentist appointment and above a mother’s birthday. For others, the idea of making that appointment, or taking that long walk to the clinic, is one of the most nerve-wracking experiences they can imagine. However, in an age where the numbers of people diagnosed with HIV are increasing, has our natural fear of the unknown become a luxury we simply can’t afford?

Many years ago it was a scary disease. We called it AIDS and it became a name associated with sin and death. The massive number of infections, particularly in the gay community, were staggering, and as the death toll slowly crept up, nations across the world panicked. It’s impossible for any society to come through such a dark time and emerge unscathed, and so the fear of a silent killer left a scar on our cultural memory which has never really healed, and the mere mention of HIV and AIDS still has a way of stopping conversations.

Thankfully, things have changed since then and treatment for HIV and AIDS is better now than it has ever been. People who have the condition are now finding that their lives have not changed completely, and they are still able to live as long and do all the same things they could before. It’s true that they now have a few additional concerns to think about but with the help of medication, HIV is now manageable. However, it seems that attitudes have not moved on as much as the treatment, with people still finding themselves afraid, ashamed and worried that their lives will never be the same again.

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To try and get a better understanding of the feelings and attitudes behind the diagnosis, I spoke with Sona Barbossa, a counselling team leader with the GMI Partnership. Over the course of our conversation, Sona revealed that the anxiety surrounding being tested and anxiety about the results is something which does prevent people from being tested regularly. ‘I don’t think it’s so much a fear about the test itself, but more fear of what the results might be and having to deal with that. There is still a stigma around it and I see many guys who have not been tested for years because they’re afraid of finding out the results and having to make decisions upon learning their results. Also, there’s still a lot of thinking around where people believe that it won’t happen to them, so they don’t see the point in being tested.’ When I asked Sona if she thought attitudes have changed much since HIV first came to public attention, she told us she didn’t think so. ‘People still connect HIV with promiscuity, the gay scene and with drugs. There’s also still a lot of shame and guilt that surrounds the condition, which I think plays a large role in whether people want to be tested or not and can prevent people from making those all important first steps to be tested.’

The fear of the condition is more than understandable. Even with new treatments being developed every day, HIV is still a lifelong condition which also has lifelong consequences. There’s also a very real stigma still attached, which has always been associated with homosexuality, promiscuity and intravenous drug use. This forces a lot of people who have HIV into a double life to keep it a secret from their friends and family. Sona herself pointed out during our conversation that a lot of people still feel like they will be shunned by their loved ones. ‘The fear of being judged and being looked at differently does form a large part of why people may keep this condition from their loved ones. They think that people may change towards them, and worry that their friends won’t accept them any more, and obviously the worry that their families won’t accept them any more. With this kind of attitude pervading society, it’s little wonder that people would be put off from learning their status, as it forces people to think about a lot of things before they even go to have the test done.’

According to statistics gathered by the gay men’s health charity GMFA, 59,000 gay men were tested for HIV last year. While this seems like a large figure, I was later informed by Carl Burnell, the CEO of GMFA, that this figure may only make up 15-25% of the estimated gay population. This becomes all the more worrying when GMFA’s recent statistics uncovered that 82% of new HIV infections are actually passed on from people who have not been checked themselves. The organisation has consistently fought to encourage people to learn their status and  to be checked at least once a year, however in the course of their work, they find that anxiety about HIV is having a definitive effect on preventing people from being checked. When they examined the reasons for not going to be tested, they found that 30% of those asked noted that nerves about their results were a factor, with a further 10% going on to say this was the main thing stopping them from taking the test. Burnell also noted that though people are still keen to avoid becoming HIV positive, their awareness that the condition is all around them is decreasing, and this can potentially lead people to take risks with their sexual health. He also commented that there is still a popular misconception among young gay men that HIV is not something they need to worry about, as it’s still considered by some to be a disease that only harms older people.

However, it isn’t just methods of treatment which have moved on, but also methods of detection. Time was, that if you wanted to have an HIV test you would have to go to your GP and ask for the test specifically and then be referred to have your blood taken and examined. The process would take anywhere between 3 days and 2 weeks depending on the area, and the very idea of waiting for the results could be described as hell-on-earth for people who were brave enough to be tested in the first place. Now people are able to walk in and be tested within half an hour and have their results the same day, sometimes within minutes. Similarly, thanks to the work of organisations like the Terrence Higgins Trust (THT), people are now able to order and administer the test in the privacy of their own home, send off a small vial of blood and have their results sent to them via email or even text. The sad fact is that even with all these different ways to be diagnosed, not enough people are going out and being regularly checked.

HIV TESTINGHere at So So Gay we like to practice what we preach, so when it came to writing a feature that dealt with being fearless and going to get tested, I decided to go out and take the test myself. Having been in a long-term relationship and suddenly single again, it seemed like the right time to know my status, since I was back on the dating scene. I picked the 56 Dean Street clinic in London for its walk-in service and quick results. The staff were amazing and they made me feel reassured every step of the way. They made me feel like, even though I may have been nervous to be there, I was doing the right thing by being tested. I must admit I was scared – after all the idea of drawing blood at the best of times is scary, especially for a needle-phobe like me –  but I felt that whatever the result, it would all be OK. It’s impossible to be in that situation and not wonder about what happens if you get a bad result and I was no different as I sat in the waiting room. However, I was seen by the nurse extremely quickly and within a few minutes of me sitting down in the private room, we were ready to draw blood. The nurse was a saint and kept me calm, and reminded me that even if I was HIV+, then I would still be the same person I was when I walked in, and that there are services out there to help me every step of the way. When my result came back, I was thankfully HIV-. Although I was relieved, I also knew that being tested was only half the battle, so I went and made an appointment to come back in 6 months to be checked again. I felt like it was a responsible thing to do, not just for my own health, but also for the benefit of anyone I might come to know in the future.

The truth is that it’s very easy to get ‘caught short’ in life and sometimes that leads us to take risks when we know we shouldn’t. The true test is when we make these mistakes, we have to make sure that we take the time to know our own status, since it doesn’t just affect us, but also the people we care about. HIV is no longer the death sentence it used to be and people are able to live normal, healthy and happy lives like they did before. However, this is thanks to the amazing progress we have made in treating the condition and we can only begin to do that when we make the decision to get tested and keep on top of our health. It’s a scary prospect to some and no one takes that for granted, but by taking the chance to be tested, you could be buying yourself years of life. Speaking to Carl at GMFA, he even proclaimed that we could well see the cure to HIV in our lifetimes, so let’s all make sure we are all there to see it.

Some key facts to remember:

  1. HIV is a disease which is transmitted by the sharing of bodily fluids, i.e. blood and semen. It does not discriminate against people who are older, more sexually active or people who use drugs.
  2. There is currently no cure for HIV, so people with the condition have it for the rest of their lives.
  3. With an early diagnosis people are able to live long lives. If it is left untreated, then it becomes harder to fight.
  4. People who have HIV are still the same people they have always been, and it is wrong to judge people or treat them differently because of their status.
  5. Condoms are not 100% effective. There is still a chance you can get HIV if you are safe, so you need to get tested at least once a year to know if you have the condition or not. The only ‘safe’ sex, is no sex.

Above all, remember that we have a responsibility to care for each other as well as for ourselves because, regardless of positive or negative, we are still united as a community. Be brave, go out and get tested so you know your status. There is an old saying which says ‘knowledge is power’, but in this instance it would be more accurate to say ‘knowledge is life’, whatever your status may be.

Via So So gay

HAVE YOU EVER HAD A HIV TEST?

If you’re interested in having a HIV test, we offer a completely free and confidential rapid HIV test and you’ll get the results within 60 seconds from a simple finger prick test. We use the Insti HIV test produced by BioLytical laboratories. The test is 99.96% accurate from 90 days post contact for detecting HIV 1 and 2 antibodies. We also have a mobile testing van which is often out in communities providing mobile rapid HIV tests. Appointments are not always necessary, if you would like a test, please contact us on 0116 2559995

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Researchers Work on Developing New HIV Vaccines

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Scanning electron microscope image of a lymphocyte with HIV cluster. (Image: National Cancer Institute)

With the recent launch of MIT’s Institute for Medical Engineering and Science, MIT News examines research with the potential to reshape medicine and health care through new scientific knowledge, novel treatments and products, better management of medical data, and improvements in health-care delivery.

Studying infectious diseases has long been primarily the domain of biologists. However, as part of the Ragon Institute, MIT engineers and physical scientists are joining immunologists and physicians in the battle against HIV, which currently infects 34 million people worldwide.

The mission of the Ragon Institute — launched jointly in 2009 by Massachusetts General Hospital (MGH), MIT and Harvard University — is to develop new HIV vaccines through better understanding of how the immune system responds to infection. Bruce Walker, the MGH physician who directs the institute, says it was important to enlist engineers and physical scientists, who have usually been excluded from traditional HIV research, to help in this effort.

“It seemed to me that if we could break down some of those silos, there were probably tools in the toolbox that could be applied to the problem right now that weren’t being applied,” Walker says. “MIT has brought a lot to the table — not only expertise, but also a different way of thinking about approaching problems.”

The Ragon Institute also encourages its researchers to develop new technology and pursue ideas that might not be funded through traditional channels. These include new materials for vaccine delivery and new technology for studying the virus’s interactions with the immune system.

“It has encouraged people, like the engineers here, to start working in areas that they wouldn’t have worked in otherwise,” says Christopher Love, an MIT associate professor of chemical engineering and an associate member of the Ragon Institute. “That kind of momentum can sometimes be hard to establish. The Ragon has been a catalyst for new research innovations and a very effective one at that.”

Single-cell analysis

Love is now helping in the search for a new vaccine using technology he developed to study immune responses of individual cells. His system allows thousands of immune cells to be studied at once: The cells are placed into tiny wells on a plate, and secretions from each cell are imprinted on a glass slide placed over the wells. The slide is then tested for the presence of specific proteins such as cytokines, which provoke inflammation.

Because each cell has its own “address” on the slide, the secretions can be traced back to individual cells. This technology generates a huge amount of data for each cell under study. “You can now make measurements on 10,000 cells and generate 20 to 30 parameters of data on each cell that’s present in that sample. That kind of data density hasn’t really been feasible previously,” says Love, who is a member of MIT’s David H. Koch Institute for Integrative Cancer Research.

Love first used the system to study immune-cell responses to food allergens and infectious agents, and began using it to study HIV responses after becoming part of the Ragon Institute in 2009.

In a study published in 2011, Love and his colleagues analyzed the cytokines secreted by T cells from HIV-infected patients, as well as the cells’ ability to kill HIV-infected cells. Previous studies had suggested that high levels of a cytokine called interferon gamma might correlate with cell-killing ability, but the MIT team found that while the percentage of T cells that secrete interferon gamma is similar to the percentage of those that kill infected cells, the populations do not entirely overlap.

Love is now searching for biomarkers that do reveal which T cells are most effective at killing HIV-infected cells. He also hopes to scale up the device so it could be used to rapidly monitor the immune responses of participants in vaccine trials.

New vaccine targets

Arup Chakraborty, director of the Institute for Medical Engineering and Science (IMES) and a professor of chemical engineering, chemistry, physics, and biological engineering at MIT, who uses computational models to study the immune system, had never studied HIV until meeting Walker in 2008. He is now using his computational approaches to seek better HIV vaccine targets.

So far, the virus has proven very difficult to target because it mutates so rapidly. In recent years, scientists have tried targeting amino acids in HIV proteins where mutations appear to weaken the virus. However, this approach has had limited success because compensatory mutations elsewhere in the viral protein can overcome the harmful effects of the vaccine-induced mutation.

To overcome this, Chakraborty’s lab identified groups of amino acids in HIV proteins that evolve independently of those in other groups. In a subset of these groups, computer models predicted the virus to be vulnerable to multiple simultaneous mutations. By targeting amino acids in such groups, vaccine designers may be able to cut off the virus’s escape route.

In 2011, Chakraborty and Walker showed that a particularly vulnerable group exists in a subunit of the Gag protein, which forms the envelope that surrounds the virus’s genetic material. They also found that T cells in patients who can fight off HIV on their own disproportionately target the amino acids identified in the study. HIV strains with multiple mutations in these amino acids are rare, offering further evidence that these could make good vaccine targets.

Special delivery

Darrell Irvine, an MIT professor of materials science and engineering and member of the Koch Institute, is working on alternative ways to deliver vaccines. Most vaccines used to protect against diseases such as chicken pox and influenza are made from deactivated forms of the virus. That approach is thought too risky for HIV, so many researchers are instead pursuing vaccines made from protein or sugar molecules that the virus produces, known as antigens. Another possible approach is injecting DNA that codes for viral proteins.

However, injecting those molecules on their own doesn’t always produce a strong-enough immune response in the vaccine recipient, so Irvine and his lab are seeking ways to elicit stronger responses, using two strategies: delivering antigen along with another type of molecule, known as an adjuvant, that helps to provoke the immune system, and delivering the antigen directly to the target cells, using nanoparticles or polymer films.

Recently, Irvine and his colleagues developed a new polymer film that can deliver DNA vaccines under the skin. DNA vaccines were first tested about 20 years ago, and found to elicit strong immune responses in rodents. However, DNA vaccines have thus far failed to provoke any protective response in human clinical trials.

With the new polymer film developed by Irvine and his colleagues, DNA vaccines are embedded in layers of polymer films that gradually degrade, releasing the vaccine over days or weeks. The film also includes an adjuvant consisting of a strand of RNA similar to viral RNA. This molecule provokes inflammation in the target tissue, which helps to recruit immune cells to the area, so they can encounter the antigen encoded by the DNA.

The vaccine-delivering film showed success in tests of mice, and the researchers now hope to test it in nonhuman primates.

Much of this work would probably never have happened without both funding from the Ragon Institute and the interdisciplinary collaborations that have arisen because of the institute.

“It’s been absolutely fantastic for me and many of the MIT faculty that have been involved,” Irvine says. “There are really two paths being followed at all times: a very focused mission to try and get an HIV vaccine developed, but also an interest in making sure that we don’t miss new opportunities in the basic science that might bring totally new vaccine concepts forward.”

via mit.edu

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