The mechanism that prevents a percentage of people infected with HIV develop AIDS could be key to its prevention through vaccination.

The HIV is the cause of AIDS (Acquired Immunodeficiency Syndrome). HIV attacks CD4 cells, responsible for coordinating the immunity and thus protect the body from pathogens. Going down alarmingly the number of CD4 cells, AIDS patients are prone to serious infections that go unnoticed in healthy people, can produce death.

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From the onset of disease in the early 80’s, have improved treatment retroviral extending the life and quality in patients with AIDS. It has also managed to raise awareness of the importance of preventing infections by different programs campaigns and achieving a reduction in the number of new infections, but attempts to create a vaccine so far have proved. Researchers at the Massachusetts Institute of Technology (MIT), Harvard University and Massachusetts General Hospital (MGH) have recently published in the journal Nature a discovery that could lead to the development of an effective vaccine against HIV.

Elite Drivers

Normally, people infected with HIV develop AIDS in less than 10 years. However, there is a group of people (about 1%) are called elite controllers. These patients, despite being infected with HIV virus never develop AIDS or the disease takes many years to manifest. Since 1990 we have studied the possible mechanisms behind this natural immunity and researchers from MIT and MGH have discovered that it could reside in leukocyte antigen HLA B57.

What is HLA B57?

A set of genes that encode the identification and signaling the immune system and are recognized under the name Major Histocompatibility Complex, Which in turn are grouped within the HLA system. These genes make the surface of individual cells express a number of proteins that will cause the cells of the immune system can distinguish self from foreign (hence, the HLA system is important to prevent rejection of transplanted organs ).

There are several variations in the population in the genes encoding the HLA system, so that these proteins have a high variability within the population. Thus, HLA B57 antigen is expressed in a very small percentage of the population (3% of Caucasians, reaching 8% in the ethnic Tamil from South Africa). However, the antigen HLA B57 is present in 1,100 of the 1,900 elite controllers studied.

How did the carriers of HLA B57 against the HIV virus?

Elite drivers who carry the HLA B57 gene expressing generate a greater number of T lymphocytes that carriers of other variations. Furthermore, these T cells can recognize a large number of different proteins, including those expressing the HIV virus on its surface, even when this mutation. So, are attached tightly to the virus, infection, successfully maintaining the controlled and, therefore, slow the progression and expression of the disease. However, this genetic characteristic also makes them more likely to suffer autoimmune diseases, As T cells bearing HLA B57 can treat the body’s own cells as if they were invading, attacking them and causing an inflammatory reaction.

Why this discovery is a breakthrough in the fight against AIDS?

Knowing the mechanism by which the body defends itself from HIV infection, can we develop vaccines that activate T lymphocytes act the same way as naturally occurring in people who carry the HLA B57 antigen.