In vivo replication of MMTV is enhanced in the absence of BST-2. (A) Naïve female age-matched C3H/HeN (n = 3) and C57BL/6 (n = 3) were profiled for BST-2 expression by qPCR analysis of BST-2 mRNA levels in popliteal lymph node, spleen, bone marrow derived DCs (BMDC), and bone marrow derived macrophages (BMMΦ). Data are presented as fold change in BST-2 level relative to NMuMG BST-2. (B-E) Naïve age-matched C3H/HeN mice were inoculated with siRNA (n = 5), siControl (n = 5), or PBS (No siRNA, (n = 5) subcutaneously on the hind foot pad. Forty-eight hours after inoculation, mice were infected with MMTV on the same footpad. Cells of the draining popliteal lymph nodes (B-D) or spleen (E) were used for DNA and total RNA extraction or flow cytometry. (B) qPCR analysis of BST-2 mRNA 48 hours after siRNA inoculation, presented as fold change in BST-2 level relative to siControl treated mice (C) Flow cytometric analysis of surface BST-2 following in vivo siRNA treatment showing scatter plot of the gated cell population (upper panels) and % of BST-2 expressing cells (lower panel). Inset in the lower panel is mean florescence intensity - MFI. (D) qPCR analysis of proviral DNA in the popliteal lymph node of infected mice, presented as fold change in viral DNA relative to viral DNA in siControl lymph node at 24 hours after infection. (E) qPCR analysis of proviral DNA in the spleen of infected mice, presented as fold change in viral DNA relative to viral DNA in siControl spleen at 24 hours after infection. Error bars are standard deviation, p is significance level. All experiments were performed with either 3 or 5 mice per group and repeated at least three times with similar results.