Posts tagged hiv vaccine
HIV’s Ability to Disguise Itself: Can a Vaccine Hit a Moving Target?
The quest to eradicate HIV is proving to be an extremely difficult. One of the reasons for this is due to HIV’s ability to disguise itself. It is like a shifting and ever-changing target that the immune system finds impossible to keep up with. Determining how best to neutralize and beat the infection, and to solve this part of the puzzle, has been the subject of much debate and study. One recent bit of information could help move the process along and, perhaps, could even result in an effective vaccine.
Antibodies are specially designed to attack intruders that invade the body. They do this, and remarkably well, by attaching themselves to the invader. Thankfully, there are known antibodies that can neutralize HIV. The problem is, once danger is detected, the virus is able to shift the location where antibodies attach to HIV. By doing this, the virus evades the host’s immune response and continues to infect nearby cells.
One research team did find that there are sites on the virus that do not shift as readily. Another encouraging finding is the most effective antibodies latch onto these sites and destroy the virus before it has an opportunity to escape. Even when the site shifts, some of the antibodies were able to follow the shift and enter at the new site. This important information could not only lead to new vaccines against HIV but to other difficult viral infections, as well.
Further research is needed to learn how best to target the virus. Moreover, additional study of these antibodies, and how to increase their number within the body, will aid in developing new vaccines and treatments. Further investigation into HIV’s ability to disguise itself will help in identifying the best sites on the virus for antibodies to access. In the meantime, researchers are optimistic that this new information has put them on the path to winning the war against HIV.
HIV Adaptation: Three Decades On
Ongoing studies of how new treatments are performing against HIV are a mainstay of research. Ideas and theories for new treatments and vaccines are continually being studied and debated. Now, three decades since HIV broke onto the scene in North America, one group decided it was time for an investigation into two different areas: First, to find out just how the virus adapts to humans and, second, to see if the virus has changed since it was first introduced. The idea required extensive research on HIV adaptation and it also involved considerable back tracking. However, the effort paid off.
How HIV responds to current drug therapies has been well documented. However, exactly how HIV adapts to its host, humans, has never before been looked into. Going back nearly thirty years, and retrieving important molecular information on HIV, was a tedious task. Nevertheless, in spite of the challenges, the team found what they needed. Based on these findings, it is clear that HIV has adapted over the last couple of decades to humans. What was the process involved? And, what does it mean for us today?
First, the virus infects the host and begins to multiply. This process does not go unnoticed by the host’s immune system, which then immediately dispatches help. This internal fight helps keep the virus in check. Current drug therapies help too. After years of fighting, the immune system can tire out. As time passes, and the virus becomes accustomed to its host, it also begins to adapt to the onslaught brought on by the immune system. After enough time passes, the invader can become quite adept at evading the immune attacks. This is very bad for the host, who has lost the ability to naturally protect itself from the virus.
HIV adaptation has begun, but at this point, the adaptation has been minor. In fact, these changes are so minimal that researchers are confident that current therapies, and vaccines in development, will still be effective. Knowing that the virus can adapt and change is important, as researchers will remain alert to this and adjust research and strategies accordingly.
How Broadly Neutralizing Antibodies May Change the World for HIV
One of the things that make it so difficult for scientists to discover a vaccine or a cure for HIV is that the virus rapidly mutates. There are many strains of HIV around the world, mainly due to the virus’s propensity to mutate several times within a person in an effort to fight against treatment that is tailored to that individual. Broadly neutralizing HIV antibodies, however, can take on various versions of the retrovirus that are found across the globe.
Much of the data comes from the body of one woman in Africa whose immune system started creating these antibodies spontaneously when she became infected with the virus. Researchers were able to identify these antibodies within the woman, extract them, and proceeded to create clones of the antibodies in a laboratory. After conducting multiple experiments, the scientists postulated these so-called broadly neutralizing HIV antibodies could be the future of HIV research.
One thing researchers looked for is how the antibodies developed. They believe that this may be the key to unlocking a vaccine for HIV. Most people who become infected with the virus do produce antibodies, and thus able to be tested as positive, but do not create broadly neutralizing HIV antibodies and cannot effectively combat HIV in its multiple forms as the virus evades treatment within the body.
Animal studies are the next step for these broad-spectrum antibodies. Once they are deemed safe and effective, human trials follow. Scientists are in the process of cloning the antibodies to ensure supply lasts through the various levels of testing, and hopefully reach one step closer to a HIV vaccine, leading to disease eradication one day—just like smallpox.
Further Advances in the Search For an HIV Vaccine
HIV is a remarkable organism. While it may be microscopic, the activities that go on are quite impressive. At the very least, there is a lot of work that occurs in the virus’ life. It is the study of some of these functions which has scientists hopeful that a new vaccine may be just around the corner. One study in particular has caught some special attention.
The HIV itself looks like a spiny or spiky ball. At the ends of these spikes are three proteins. These are special proteins and they are called gp120. The way they are arranged on their spikes resembles the petals of a flower, in that they can open and close. The gp120 molecules have specific functions or jobs to do. One of those includes helping the virus bind to other cells. The proteins can also stay closed and hide these binding areas. Think of an airplane coming in to land on a landing strip. If the strip is concealed, the plane will fly right over it. HIV works in a similar way when it comes to the immune system. The immune system sends out antibodies in an attempt to fight the infection. These antibodies hunt the HIV and look to destroy it; however, the gp120 can keep the HIV safe by concealing the landing space or binding area. If the antibodies cannot bind with the virus, infection occurs.
Each of the proteins on the HIV is equipped with tiny molecules called amino acids. Scientists have discovered that by altering certain levels, the amino acids can either open or close the gp120 proteins. This is good news, as by controlling this process, scientists can help the immune system find and kill the virus before infection takes place. This means that if further testing is successful, effective HIV vaccines may be appearing in the near future.
New Spin on an Old Theory Brings Researchers One Step Closer to an HIV Vaccine
Testing and experimentation to find an HIV vaccine has been ongoing for nearly thirty years. Over the past three decades, there have been numerous approaches to the subject in order to find one that might work. One of these includes the thought of targeting how the virus attaches itself to a healthy cell. It is hoped that by doing this, an attack from the immune system would target and eliminate the threat, thereby avoiding infection. Recent experimentation in Europe yielded some promising results.
By taking an envelope protein called gp41—which is part of HIV—and engineering it, researchers were able to come up with one way of slowing or even preventing an infection. What makes this protein so special is that it is responsible for attaching itself to human cells. By preventing this bond, it is hoped a successful vaccine can be developed.
This idea is not a new one. It has been extensively researched. What makes this approach novel, however, is the engineering behind it. How the protein is designed by engineers enables it to potentially alert the immune system. For example, it can attach to T-cells and trigger an immediate response. This, in turn, can aid in ridding the body of the virus.
There is a setback with the design, though. The problem lies in the fact that not all immune cells are infected via the gp41 protein. This leaves certain cells open to attack. While this needs to be addressed, it does not mean all is lost. Researchers are hoping to create a vaccine that tackles the problem in different ways. The use of gp41 is one way, and perhaps when combined with another method, an effective vaccine can be produced. When this does happen, it will be a major victory in the battle against HIV.