Scientists successfully disarm HIV virus for development of possible vaccine

Scientists at Imperial College London and Johns Hopkins University have made a medical breakthrough, discovering that removing the cholesterol from the HIV virus’ membrane causes the cell from being able to attack the immune system.

When HIV attacks the human body, the first line of response comes from the innate immune response system. However it is believed that the HIV virus over-stimulates this response causing it to damage the next layer of defense, called the adaptive immune response. In most cases, the adaptive immune response would create cells to fight off the invading pathogen. In the case of HIV though, with the innate system weakening the adaptive system, the body becomes almost defenseless against the HIV virus.

Removing the cholesterol from HIV cells means the innate immune system would not over-react, allowing the adaptive cells to form a proper and specialized cell to fight off the HIV pathogen.

Dr Adriano Boasso from Imperial College London said the following:

“HIV is very sneaky. It evades the host’s defences by triggering overblown responses that damage the immune system. It’s like revving your car in first gear for too long. Eventually the engine blows out.

“This may be one reason why developing a vaccine has proven so difficult. Most vaccines prime the adaptive response to recognise the invader, but it’s hard for this to work if the virus triggers other mechanisms that weaken the adaptive response.”

The HIV cells easily infect the body by merging itself to various types of cells in the human body and use the cholesterol to remain in a very fluid state, allowing it to interact with various types of cells. Getting into details, the plasmacytoid dendritic cells (pDCs) (at the innate immune response level) produce interferons when they interact with the HIV cells, but because of the presence of cholesterol in the HIV cell it causes interferon signal cells to be produced for far too long, which hinders the work of T cells at the adaptive level. Removing the cholesterol helps to stop pDCs from activating and allowing T cells to get to work.

They removed  the cholesterol by injecting various concentrations of beta-cyclodextrin (bCD) into the cell, which causes the cholesterol deposits to bind together. Once they extracted that bit, the cell was then essentially left with a gaping hole and became inoperable because it could not stimulate pDC cells.

With this in mind, the team of scientists could now work on a possible vaccine. While this is still at the petri-dish level, there would still have to be testing at the human level. Nonetheless it’s a great step towards a solution.