Con-focal microscopy and PLA of co-stained LHBs and CK8/18 in Huh7 expressing LHBs confirmed their colocalization. An interaction of LHBs with CK8/18 was seen by SPR technique. CK18 transfection in NIH3T3 expressing LHBs prevented the formation of large LHBs aggregates and led to a finely distributed LHBs pattern and strong colocalization with CK18. Contrarily, CK18-knockdown by RNAi caused perinuclear aggregates of CK and LHBs in Huh7 expressing LHBs. Treatment

of PTHs with Oka led to an increase in the infection rate by about two-fold, whereas no effect of Oka on HBsAg secretion could be seen in already HBV-infected PTHs. Conclusion: CK 8 and 18 are responsible for intracellular distribution of LHBs and might be relevant for HBV infectivity. These new findings might be relevant for new therapeutic options in HBV therapy. Disclosures: The following people have nothing to disclose: Martin Roderfeld, Tamoxifen Dirk Schroder, Yury Churin, Dieter Glebe, Elke Roeb Background: Viral infection activates innate immune receptors that promote interferon secretion. Interferon, in turn, triggers up-regulation of hundreds of interferon selleck kinase inhibitor stimulated genes (ISGs) that establish a broad antiviral state hostile to viral replication. Examination of the role of interferon signaling and early innate immune responses in hepatitis B virus (HBV) has been impeded by the

difficulty of infecting cultured human hepatocytes. Methods: To overcome this limitation, we prepared fresh primary culture from livers of uPA-SCID mice transplanted with human hepatocytes, Cobimetinib ic50 which enabled us to establish robust HBV infection. Cultures were inoculated

with high titer serum samples from a patient with chronic HBV infection, and changes in mRNA and miRNA expression were assayed by microarray and real time PCR. Protein profiles were analyzed by 2-D elec-trophoresis and mass spectrography. Results: HBV replicated in hepatocytes seeded at high density, but replication rates diminished at progressively lower cell densities. HBV infection induced expression of ISGs in primary cultured hepatocytes, including up-regulation of cytokines such as IL-8 and acute reactant proteins such as SAA1 and SAA2. Analysis of protein profiles also showed ISG up-regulation. To determine why cell dilution resulted in decreased HBV replication, we compared up and down regulated genes and proteins by microarray analysis and protein 2-D electrophoresis. Genes expected to be important for HBV infection and replication such as NTCP were down regulated by cell dilution. Some ISGs, such as MxA, were up-regulated during HBV infection, although conclusions from protein analysis were limited. Reduced cell density down-regulated factors involved in cell polarization and hepatocyte-specific activities, especially among HNF4a and PPARG-regulated genes. Conclusions: HBV infection is detected by hepatocytes and leads to robust ISG activation in primary cultured hepatocytes.