Some people who are infected with HIV naturally produce antibodies that can neutralize several strains of the mutating virus. Now, scientists are working on a vaccine that can prevent HIV infection and have found that the right precursor cells for one kind of HIV broadly neutralizing antibody are present in most people.
An emerging vaccine for HIV involves immunizing people with a series of different engineered HIV proteins as immunogens to teach the immune system to produce broadly neutralizing antibodies against HIV. This strategy involves the first immunogen binding and activating special cells, known as broadly neutralizing antibody precursor B cells. These have the potential to develop into broadly neutralizing antibody-producing B cells.
In this latest study, the researchers found that the right precursor cells for one kind of antibody are present in most people. This could be huge when it comes to developing a vaccine for HIV.
"We found that almost everybody has these broadly neutralizing antibody precursors, and that a precisely engineered protein can bind to these cells that have potential to develop into HIV broadly neutralizing antibody-producing cells, even in the presence of competition from other immune cells," said William Schief, the lead author of the new study and The Scripps Research Institute (TSRI) professor and director.
The body's immune system contains a large pool of different precursor B cells. This allows it to respond to a wide variety of pathogens. It also means that precursor B cells that can recognize a specific feature on a virus are rare.
"The challenge for vaccine developers is to determine if an immunogen can present a particular viral surface in a way that distinct B cells can be activated, proliferate and be useful," said Shane Crotty, the co-author of the study from La Jolla Institute. "Using a new technique, we were able to show - well in advance of clinical trials - that most humans actually have the right B cells that will bind to this vaccine candidate. It is remarkable that protein design can be so specific as to 'find' one million in a million cells, demonstrating the feasibility of this new vaccine strategy."
The findings could be huge when it comes to developing a vaccine. It also provides a method for researchers to assess whether other new vaccine proteins can bind to intended precursor B cells.
The findings were published in the March issue of the journal Science.
