Thus, it interferes with production of proteasome-dependent MHC-I ligands [49]. IFN-γ (ImmunoTools) or IFN-λ1 (R&D) in cell culture supernatants were measured

by sandwich ELISA following the manufacturer’s instructions. Human monocyte derived DCs were prepared from HLA-A2 positive donors and left uninfected or infected with HTNV (MOI = 1.5). At day 4 p.i., cells were harvested and co-cultured with a pp65 peptide specific (NLVPMVATV) HLA-A2-restricted human T-cell line, which was kindly provided by Nils Rademacher (Berlin). In a click here 96-well U-bottom plate, 104 target cells (DCs) per well were incubated with different ratios of effector T cells (pp65 peptide specific HLA-A2-restricted T cells). Co-cultured effector and target cells were incubated with lysates of uninfected or HCMV-infected fibroblasts for 36 h. Effector T cells stimulated with 100 ng/mL phorbol 12-myristate 13-acetate (Sigma) alone were used as a positive control whereas uninfected or HTNV-infected DCs without T cells were used as a negative control. Subsequently, plates were centrifuged at 1000 × g for 5 min and supernatants were analyzed for IFN-γ by ELISA. Results were expressed as means with standard deviation. Student’s t-test Midostaurin was used to determine statistical significance of selected samples. p values below 0.05 (95% confidence)

were considered to be significant. Statistical analysis was performed using the Prism 5 software (GraphPad). We thank T. Kaiser (Deutsches Rheuma-forschungszentrum, Berlin) for assistance in flow cytometry and R. Ulrich (Friedrich-Loeffler-Institut, Greifswald-Insel Riems) for providing HTNV N protein-reactive pig serum. We are grateful to C. Priemer, M. Bigalke, and E. Lieske (Charité–Universitätsmedizin Berlin) for excellent technical assistance. This work was supported by the Deutsche Forschungsgemeinschaft (GraKo 1121 to P.L.) and the Charité–Universitätsmedizin Berlin

(to P.L.). The authors declare no financial or commercial conflict of interest. “
“As splicing much was previously found to be important for increasing Friend murine leukemia virus env-mRNA stability and translation, we investigated whether splicing of env-mRNA affected the poly(A) tail length using env expression vectors that yielded unspliced or spliced env-mRNA. Incomplete polyadenylation was detected in a fraction of the unspliced env-mRNA products in an env gene-dependent manner, showing that splicing of Friend murine leukemia virus plays an important role in the efficiency of complete polyadenylation of env-mRNA. These results suggested that the promotion of complete polyadenylation of env-mRNA by splicing might partially explain up-regulation of Env protein expression as a result of splicing.