Illustration of
how the engineered protein facilitates destruction of latently
HIV-infected
immune cells.
1) Protein and
cells, from left to right: engineered protein with yellow-and-black
CD3-binding end
and thick black HIV-binding end; latently HIV-infected helper
T cell (blue);
inactivated killer T cell (red).
2) Protein binds
to CD3 receptor on helper T cell, activating it so the helper
T cell starts
making HIV and displaying pieces of virus (red) on its surface.
3) Protein binds
to HIV fragment on helper T cell and CD3 receptor on killer T cell,
activating the
killer T cell and bringing the two cells close together.
4) Activated
killer T cell destroys HIV-infected helper T cell.
Credit: NIAID
(October 21, 2015) WHAT:
Scientists at the National Institutes of Health (NIH) have created a protein
that awakens resting immune cells infected with HIV and facilitates their
destruction in laboratory studies. The protein potentially could contribute to
a cure for HIV infection by helping deplete the reservoir of long-lived,
latently HIV-infected cells that can start making the virus when a person stops
taking anti-HIV drugs. Further studies in animals and people are needed to
determine the viability of this approach.
The researchers found that the protein, called VRC07-αCD3,
triggered the activation and killing of latently HIV-infected helper T cells
taken from patients on antiretroviral therapy when the cells were incubated in
the lab with the patients’ own killer T cells. In addition, the scientists
found a monkey-adapted version of the protein to be safe and well-tolerated
when given to monkeys infected with a simian form of HIV and receiving
antiretroviral therapy. The researchers are now studying the effectiveness of
monkey-adapted VRC07-αCD3 in the animals.