Has a Marker for the HIV Reservoir Been Found?

Antiretroviral therapy (ART) does not cure HIV infection, because the virus persists in a latent reservoir of resting memory CD4 cells that does not appreciably decay over time. Now, researchers have identified a cell surface marker that they propose may identify the HIV reservoir.

To find candidate markers, the investigators first developed an in vitro model by infecting resting CD4 cells with HIV. Of 103 genes that were induced in infected but not in uninfected cells, 16 encoded cell surface markers. Of the markers, HIV infection most specifically induced expression of CD32a, an immunoglobulin G Fc receptor.

The investigators then examined cells from 12 patients receiving ART. CD32a⁺ cells (0.012% of total CD4 cells) had 1000-fold higher le…