Figure 3. Differential BST-2 expression in murine lymphoid compartment during MMTV infection and carcinogenesis.

C3H/HeN•MMTV+ mice infected via milk during nursing were sacrificed after 2 pregnancies (n = 5, age = 5 months) or allowed to develop mammary tumor (n = 5, age = 5 to 7 months). Mice bearing tumor were sacrificed in accordance to the policies of the University of Iowa Institutional Animal Care and Use Committee. Lymph nodes, PBMCs, and spleens as indicated in the figures were used for RNA and DNA extraction. RNA was used for determination of BST-2 mRNA by RT-qPCR (A). Single cells from these tissues were subjected to FACS analysis for BST-2 surface protein (B). DNA and cDNA were used for qPCR detection of viral DNA (C) while cDNA was used for viral RNA detection (D). Thymi tissues obtained from naïve C3H/HeN mice and the C3H/HeN•MMTV+ and their tumor-bearing counterparts described above were subjected to RT-qPCR to determine level of BST-2 transcripts and viral RNA (E and G). Thymic viral DNA was quantified using isolated DNA (F). RT-PCR data are normalized to GAPDH and presented as fold change relative to BST-2 mRNA or viral RNA in infected or naïve mice depending on experiment. Error bars are standard deviation; ** is significance with p value less than 0.01 and * is significance with p value less than 0.05. The numbers next to the legend denote mean florescence intensity (MFI) of surface BST-2 levels. These experiments were repeated at least three times with similar results.