PGRN is an endogenous anti-HIV factor.

<p>Microglial PGRN was knocked down using RNAi 2–4 days prior to VSVg <i>env</i> HIV exposure as described in the Materials and Methods. Control cultures were treated with control, irrelevant siRNA (Ctr). The amounts of HIV (p24) and PGRN expression were determined by western blot analyses. (A) A representative western blot showing suppression of PGRN and increase of p24 following PGRN siRNA treatment. (B) Pooled densitometry data from four independent experiments showing significant inhibition of PGRN and increase of HIV (<i>gag</i> p24 express) in microglial cells treated with PGRN siRNA (vs. control siRNA). **P<0.01, ***P<0.001 by paired t-test.