Supernatants were harvested by centrifugation of cultured pDCs, which were then washed once with PBS (CellGro, Manassas, VA). The LIVE/DEAD Aqua Dead Cell Stain Kit (Invitrogen, Carlsbad, CA) was utilized to assess cellular viability via amine exclusion. Surface staining was performed using antibodies against human CD3, CD14, CD16, HLA-DR, CD83, CD86, CD123 (BD Biosciences, San Jose, CA), CD11c, CD19, CD20 (eBioscience, San Diego, CA), and BDCA2 (Miltenyi Biotec, Auburn, CA); pDCs were defined as being lineage -HLA-DR + CD11c -CD123 + . Cellular fixation and permeabilization were performed using Cytofix/Cytoperm (BD Biosciences, San Jose, CA), per the manufacturer's instructions. Following blocking of Fc receptors (Miltenyi Biotec, Auburn, CA), intracellular staining was performed with antibodies to IFNa, total IRF7, phosphorylated IRF7 (pS477/pS479) (BD Biosciences, San Jose, CA), IFNb (Antigenix America, Huntington Station, NY) or NSP2 (mAb 191). The presence of NSP2 staining of exposed pDCs was considered to be indicative of rotaviral replication in those cells. Direct conjugation of mAb 191 to APC was performed by Chromaprobe Inc (Maryland Heights, MO). Data were acquired using a LSRII and DIVA software (BD Biosciences, San Jose, CA); analysis was performed using FlowJo (Treestar Inc, Ashland, OR).