Decreased saquinavir accumulation by HAPI microglia in the presence of LPS is attenuated in TLR4 deficient mice. (A) Primary microglia were isolated from TLR wild-type (TLR4 WT) and TLR4 deficient (TLR4−/−) mice, as described. In primary microglia isolated from TLR4 WT mice, incubation with 10 ng/ml LPS for 24 hours decreased saquinavir significantly, that is, by approximately 16%. This effect was attenuated in microglia derived from the TLR4−/− deficient mice, where there was no difference between LPS-treated and untreated deficient mice or the untreated WT mice. *P < 0.05, significantly different from untreated TLR WT controls. (B) Primary microglia derived from Wistar, and (C) Fisher rats incubated with 10 ng/ml LPS for 24 hours at 37°C also showed a significant decrease in saquinavir accumulation at one hour. *P < 0.05, significantly different from untreated control cells.