Interferon ε protects primary macrophages against HIV infection

Interferon ε (IFNε) is a unique type I IFN that is not induced by pattern-recognition response elements. IFNε is constitutively expressed in mucosal tissues including the female genital mucosa. We show here that IFNε induces an antiviral state in human macrophages that blocks HIV-1 replication. In this work, we examined effects and underlying mechanisms of IFNε in HIV infection of monocyte-derived macrophages (MDMs). We found that IFNε blocked HIV replication in macrophages. It acted on early stages of the HIV life cycle including entry and reverse transcription. It did not appear to operate through known IFN-induced HIV host restriction factors. IFNε induced immune responses in primary macrophages distinct from those induced by IFNα. Importantly, we discovered a novel protective effect of IFNε in primary macrophages against HIV by surging reactive oxygen species (ROS). Gene expression profiling was performed using the Affymetrix GeneChip® Human Gene 2.0 ST Array (Affymetrix Inc., Santa Clara, CA). Total RNA was isolated from untreated or IFNe or IFNa treated-PBMC (n=4 per group)using miRNeasy Mini Kit (Qiagen), and was converted to cDNA following the GeneChip® WT Plus Reagent Kit protocol. Briefly, total RNA (300 ng) was used for 1st and 2nd strand cDNA synthesis. cRNA was obtained by an in vitro transcription reaction, and was then used as the template for generating 1st strand cDNA. The cDNA was fragmented and end-labeled with biotin. The biotin labeled cDNA was hybridized to the array for 16 hours at 45°C using the GeneChip® Hybridization Oven 640. Washing and staining with streptavidin-phycoerythrin was performed using the GeneChip® Hybridization, Wash and Stain Kit, and the GeneChip® Fluidics Station 450. Images were acquired using the GeneChip® Scanner 3000 7G and the GeneChip® Command Console® Software. Normalized and background-corrected, raw probe intensity values were uploaded to Partek Genomics Suite ver 6.5 (PARTEK Inc, St. Louis, MO) for further analysis as described