Tuesday, October 27, 2015

Nasty virus tricks

HIV latency: a high-stakes game of hide and seek

It's interesting to read about the devious way HIV, even when people are on treatment, hides itself:
In latent infection, HIV integrates its genetic material into the DNA of the patient and becomes “silent”.

A brilliant added tool is the use of a long-lived critical cell of the immune system, the resting T cell, as its preferred hiding site. These latently infected resting T cells can slowly divide and, given HIV is now part of the patient’s DNA, the HIV is passed down to the daughter cells too.

HIV usually replicates in activated T cells and can efficiently kill those cells in several ways. First, the virus directly damages the outer membrane of the cell. This membrane usually keeps the cell intact.
Following infection of a cell, bits of the virus are quickly revealed to the immune system which, once activated, can zoom in and eliminate the infected cell.

However, if the virus manages to get inside a resting cell, in contrast to an activated T cell, all the machinery needed to produce new viruses is not available and the virus life cycle essentially shuts down.

If things shut down after the virus has already entered the patient’s DNA it gets stuck there – forever.
As the article also notes, people who go off the antiviral drugs quickly get high viral counts - within weeks.

What a nasty virus it remains.

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