Here, HIV particles (coloured yellow) are seen infecting a human T cell. HIV destroys essential immune cells including CD4 T cells – which mobilise other immune cells – thereby crippling the body’s defences. Now, researchers have revealed the molecular chain of events that results in the death of these first responders. The vast majority of CD4 T cells don’t get fully infected by HIV but die anyway. It turns out that this is because the cells respond to the presence of fragments of viral DNA by initiating pyroptosis – a fiercely inflammatory form of cell suicide that lures more CD4 T cells, creating a vicious cycle that devastates the immune system. Initiation of pyroptosis depends on the activation of a protein called caspase-1. Inhibiting this protein in cells in the lab with an existing drug suppresses cell death and inflammation, raising the possibility of new therapies that target the patient’s immune response.
Written by Daniel Cossins
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