Posts tagged HIV treatment

HIV Cells in Semen Infect Through RNA Transmission

In early 2010, scientists at the University of California San Diego’s Center for AIDS Research (CFAR) discovered that seminal HIV infection among men who have sex with men is transmitted through the HIV cell’s RNA, and not the DNA as was previously thought. Later that year it was determined that this is also the case for women who are infected through sex with men – that is, through HIV cells in semen transmitting their RNA structure to the newly infected individual. Understanding this connection is critical, because, “If we want to stop the HIV epidemic, then we must know the mechanisms by which HIV uses human sex to spread,” according to the principal researcher, Davey Smith, MD, MAS. Smith is an associate professor of medicine at the University of California’s San Diego’s Division of Infectious Diseases, and is director of the CFAR’s Viral Pathogenesis Core.

The scientists made this initial discovery of the virus’s transmission by studying male partners in which one man had recently infected the other man. They compared the genetic characteristics of the HIV cells in both partners, knowing that the virus mutates at an extraordinary rate. They learned that there was more of a shared commonality between the viruses found in the seminal plasma – the semen and fluids surrounding them – than the viruses that were located in the seminal cells. HIV’s DNA is commonly found in the host’s cells, where RNA is mostly stored in the host’s plasma. With this asymmetrical commonality between the virus found in the plasma versus the virus inside the host’s cells, the scientists were able to locate the culprit of the initial transmission, which is the virus’s RNA; with this asymmetrical commonality found in every partnership of the men they studied, they determined that it is not a mix of HIV RNA and DNA infecting an individual, but that the RNA, alone, was the transmitter.

Now knowing this source of HIV transmission, scientists and researchers have been able to develop several weapons against HIV infection over the past five years. The HIV cells in semen are now understood more, and with this understanding researchers have been able to determine and develop several things. One discovery is that if a person has no detectable amount of HIV in their bloodstream, as they have been recently infected or because they are taking a successful regimen of antiretroviral medications, there can still be a contagious amount of HIV cells in their semen – and though the possibility of infection is low at that point, it is still possible. Researchers have also been able to develop vaginal gels and ointments – called vaginal microbicides – which are able to attack the HIV cell’s RNA before transmission can take place by infected semen, along with further developing antiretroviral medications which target the virus’s RNA and make it impotent towards further transmission. Though this discovery has not led to a cure within the past five years, it has certainly brought us closer to that possible cure, and has helped prevent further transmission of HIV for thousands.

How HIV Affects the Brain

HIV infection is known to cause several side effects as it invades the body. Because of advances in medicine, along with our overall understanding of what HIV is and how the virus works inside the human body, we have been able to prolong the side effects that was so disastrously prevalent in the 1980s and 1990s: death due to a completely compromised immune system. As we are now able to keep the virus essentially ineffective, even though we are still not able to eradicate it from the body, infected individuals are now able to live much longer than before, and many die of other natural causes before they develop AIDS from their HIV infection. With people now living longer than they were able to before, researchers have noticed slow-showing side effects that an elongated HIV infection can cause. One of the more feared, as well as least understood, side effects of HIV is its negative effects on a person’s mental abilities. To learn how HIV affects the brain, researchers out of Washington University in St. Louis have looked at one of the two leading theories on the subject.

The two leading theories on how HIV affects the brain are: 1) the early immune system’s responses to the infection which triggers a series of effects that slowly impair memory and mental function; 2) how the disease and co-infections commonly seen with HIV affect the brain independently of the HIV infection. The research team decided to focus on the co-infection theory, as they saw ways to judge whether these infections were indeed affecting the brain instead of HIV itself. Through statistical elimination, they determined the only co-infection which is common enough to affect so many HIV-infected individuals is hepatitis C. So, they looked at the effects of hepatitis C and the possibilities it has in affecting a brain when it is co-infected along with HIV. Knowing that this virus predominately attacks the liver led researcher David Clifford, MD, to rule out this theory, because he believes hepatitis C does not affect the brain in any directly negative manner. The study included almost 1,600 HIV infected individuals who roughly 400 were co-infected with hepatitis C. These patients were given two exams – one written and one physical – to determine any differences they may have in their cognitive and mental abilities. The exams looked at how the patients expressed themselves, made decisions, learned and retained new information, and controlled their body. The results were that there was no distinction between those co-infected with hepatitis C and those who were only infected with HIV. This lack of distinction was made even more impressive, according to Clifford, because those who were co-infected with hepatitis C were almost all older, had less of an education, and generally had lower reading and math scores than the others. They now feel the leading theory – that the immune system’s initial reactions of inflammation of the bowels and brain – is the correct one, and are working to prove this.

Are You More Immune to HIV Than You Thought?

For the past several decades, doctors and scientists could not understand why some people quickly get sick – and can die – when infected with HIV, while others seem to naturally resist the virus for several years with less damage done to their immune systems. Researchers at the University of Minnesota’s College of Biological Sciences and Medical School looked at the virus’s rapid-mutation ability, along with how it attacks the human immune system to replicate, and hypothesized that this distinct difference in how the virus differently affects infected individuals is somehow caused by the genetics of the infected host. In trying to understand why some are more immune to HIV than others, these researchers discovered a new crack in the HIV cell’s armor which helps explain this phenomenon.

HIV attacks the immune system in order to replicate within the infected host’s cells. It seeks out the immune system cells called T lymphocytes (T cells), and uses the cell’s molecular machinery to replicate within them, killing the cells when it is done with each cell. This infection eventually depletes the system of necessary T cells, leaving the infected host helpless to other invading viruses and bacteria. The T cells do have a defense against this, as they have an anti-virus protein in their arsenal – called APOBEC3 – which has the ability to block the HIV cell’s replication process. If they are successful, they can effectively stop the virus from replicating and eventually clear it from the system as the virus cells die off. Unfortunately, HIV has developed a counter-attack to this protein, a protein of their own – called Vif – which attach themselves to the APOBEC3 cells and trick the T cells into destroying their own protein, leaving them defenseless to the virus’s replication and destructive abilities. To learn why some seem to be able to naturally fend off the virus – at least for a lot longer than others – researchers looked closer at these proteins. They found strong clues as to why some immune systems work better against the virus than others.

Some people have a greater ability to create a version of the APOBEC3 protein, which is known as APOBEC3H. This particular form of the protein is boosted whenever someone is infected with HIV, which made the researchers believe this plays an important role in the immune system’s defense against HIV. What they found was a confirmation of this assumption, as people with a more stable accumulation of the APOBEC3H protein seem to be more naturally immune to HIV than those with a more unstable accumulation of this protein. Whenever the infecting HIV cells had a weaker version of their Vif protein (as constant mutations cause the virus to be varied in its strengths and weaknesses), the infected individual with a stable APOBEC3H protein in their T cells had a better time limiting the HIV cells from replicating. This was not the case if the infecting virus cells were equipped with a stronger Vif protein. This discovery helps scientists and doctors with a new path towards attacking HIV, with a possible road to a cure. The more we can suppress the virus’s Vif protein, the more our natural immune system has a chance to combat against the infection. Coupled with a strong antiretroviral regimen, this could help stop the virus from replicating, and possibly killing it outright.

Target Found in HIV Cells

Target Found in HIV Cells: New and Promising Results

HIV treatment is something researchers and scientists are continually pursuing. This is because, as the HIV cells mutate and become resistant to some medications, new medications need to be developed and varied types of treatment need to be utilized. In this pursuit, researchers have identified a new target for eliminating HIV replication and preventing the spread of the HIV cells in the body. This promising target found in HIV cells deals with the ‘activation’ period HIV has after a dormant phase. The virus cells can lay dormant for months, even several years, before it suddenly ‘awakens.’ HIV then begins its erratic replication process, destroying the body’s immune system in the process.

Scientists believed for many years that this activation process – the awakening of the HIV cells in the body – is caused by two components, the protein that HIV produces, called Tat, and the CycT1 protein. Indeed, they thought CycT1 protein was the only activation protein which caused Tat to activate the HIV cell and start the replication process. The most recent discovery is of a new protein – Ssu72 phosphatase – which seems to also be intimately connected to this activation process.

After this discovery, and subsequent studies to identify that this protein is indeed involved in the activation process of HIV cells, several new treatments are now thought to be possible. The first protein involved in causing Tat to start the HIV replication process – CycT1 – is used by the body for normal activity. Therefore, it cannot be a target of anti-HIV drugs (without disrupting the normal bodily activities it is involved in). Ssu72, however, is not used in normal body processes and can be targeted by anti-HIV drugs. This target found in HIV cells is now being studied as a means to eliminate or disable this protein—long before it starts the Tat’s process of HIV cell replication.

HIV Infected Individuals and Age Related Diseases

HIV Infected Individuals and Age Related Diseases: Appear at Similar Age as in Uninfected Adults

Heart attacks, cancer, and kidney failure among HIV-infected individuals has been thoroughly researched and the data shows that infected individuals are more likely to develop one of these diseases than people who are not HIV positive. This research began to be compiled in the mid-1990s, when those infected with HIV were starting to live longer thanks to new antiretroviral medications. Before these drugs were created, contracting HIV was almost certainly a death sentence. When HIV/AIDs first came onto the scene, the HIV cells would eradicate the immune system, the person would develop AIDS, and common diseases like the cold or influenza would ravage the body and kill the host. In the years since, however, antiretroviral drugs have been developed and continually improved upon, and HIV has become a manageable disease. In fact, many HIV-positive individuals have been able to live out their lives with the infection and, in the U.S. and other developed countries, are now dying of non-HIV related circumstances. With the numbers of older HIV-positive individuals growing, the amount of research on those in this group has increased. The latest studies now suggest that among HIV infected individuals, age-related diseases appear at similar ages, as compared with uninfected individuals.

Researchers at the Johns Hopkins Bloomberg School of Public Health used data from almost 100,000 individuals, both infected and uninfected, who suffered from age-related diseases between 2003 and 2010. The results confirmed that those who are HIV-infected tend to develop heart attacks, cancer, and kidney failure much more commonly than in uninfected adults. However, it also showed that the ages of those developing heart attacks and cancer were the same in both infected and uninfected patients. Moreover, kidney failure seemed to only have a six-month gap between infected patients and patients who were not HIV positive. This news, that among HIV infected individuals age-related diseases appear at similar ages regardless of HIV status, shows that the timeline of getting checked for these diseases does not have to be significantly altered. However, the importance of checkups is still much greater for HIV-infected adults.

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