An experimental vaccine to prevent human immunodeficiency virus (HIV) infection was designed by Mexican Max Medina Ramírez, a postdoctoral researcher at the Academic Medical Center of the University of Amsterdam in the Netherlands.
This candidate for HIV vaccine is capable of initiating broad spectrum neutralizing antibody precursors (bNAbs) against HIV. The vaccine candidate was developed using protein engineering techniques that allowed stabilizing the envelope of the HIV virus, also known as “trimer” –used by the virus to infect and, at the same time, circumvent the immune system.
In addition to the stabilization of the trime, the structure was modified to favor the activation of bNAb precursor B cells, which have the ability to prevent the spread of the virus.
“This experimental vaccine was tested in several animal models and our results were published in the Journal of Experimental Medicine under the title Design and crystal structure of a native-like HIV-1 envelope trimer that engages multiple broadly neutralizing antibody precursors in vivo.”
In an exclusive interview for Ciencia MX, the researcher commented that he has already generated a second version of the possible vaccine, which will be tested in a next phase in a clinical study. “The objective is to start a clinical study in the course of the next twelve months. We are currently in the stage of scale production of this experimental vaccine.”
Wrapped HIV virus, a key component of the experimental vaccine
The scientific literature reports that approximately 50 percent of people living with HIV eventually develop bNAbs, usually one year after maintaining an active infection. Now it is known that this type of antibodies has the ability to neutralize most of the viral subtypes that circulate worldwide.
Unfortunately, patients who develop these antibodies do not benefit from it, given that by the time these antibodies are naturally generated, the virus would have already generated viral reservoirs (that is, it found where to hide from the immune system). In addition, once the infection is established, the virus can adapt and escape easily under pressure from the immune system. The key is to stimulate the immune system to develop bNAbs before the virus attacks.
Broad spectrum neutralizing antibodies
The discovery of these antibodies revolutionized the field of HIV vaccine research. Dr. Medina Ramírez undertook the task of selecting these antibodies and adapting them using protein engineering to use them as molecular tools in the design of an HIV vaccine.
“Clearly there are other research groups that focus their work on initiating a broad spectrum neutralizing response. However, these groups use other types of antigens to initiate the immune response; unlike our strategy, other groups use antigens that do not maintain the native structure of the HIV envelope, in other words, they do not use the ‘native trimer’ as we have achieved. The above is essential to expand the possibilities of initiating the correct answer.”