Detailed functional analysis of the effect of Fut2 on HBV infection may be the key for defining the HBV life-cycle and may lead to the discovery of a new therapeutic target for HBV infection. Disclosures: Shuichi Kaneko – Grant/Research Support: MDS, Co., Inc, Chugai Pharma., Co., Inc, Toray Co., Inc, Daiichi Sankyo., Co., Inc, Dainippon Sumitomo, Co., Inc, Ajinomoto Co.,

Inc, MDS, Co., Inc, Chugai Pharma., Co., Inc, Toray Co., Inc, Daiichi Sankyo., Co., Inc, Dainippon Sumitomo, Co., Inc, Ajinomoto Co., Inc, Bayer Japan The following people have nothing to disclose: Takayuki Shiomoto, Masao Honda, Takayoshi Shirasaki, Bortezomib Kazuhisa Murai, Tetsuro Shimakami, Seishi Murakami The pathogenesis of HBV-associated ALF is poorly understood. Access to multiple liver specimens and serum from 4 well-characterized Italian patients with HBV-associated ALF, who underwent liver transplant within 1 week of admission, provided a unique opportunity to investigate the role of viral and host factors in the molecular pathogenesis

of ALF. Following our initial observation of an overwhelming B cell gene signature in ALF, with massive intrahepatic accumulation of plasma cells secreting IgG and IgM, here: i) we analyzed the biological and genetic characteristics of the HBV strains recovered from serum and liver of 4 patients with ALF; ii) we cloned and expressed HBsAg and HBcAg from the patients, which were used to screen the corresponding phage-display Fab libraries (IgG1 and IgM) generated from the liver of each patient to selleck identify the molecular targets of the antibodies produced in the liver; and iii) we performed extensive sequence analysis of these antibodies to investigate their variable region usage and somatic mutation rates. The complete HBV sequence from each patient showed a 2-3 %nucleotide mutation rate compared to a reference sequence. Abiraterone nmr All patients harbored the pre-core stop mutation, and data from next-generation sequencing confirmed the presence of this mutation in almost 100 %of the viral populations both in liver and in serum.

HBcAg was the most variable region of the entire genome, with a mean number of amino acid changes of 12.75 (range 9 to 17) compared to a reference sequence, scattered throughout the protein, with clusters within B- and T-cell epitopes, particularly within the immunodominant B-cell epitope (amino acid 74-84), indicating that HBcAg is under strong immune pressure. By contrast, no AA changes within HBcAg were seen in reported sequences of patients with classic acute hepatitis B. Screening of 8 phage libraries showed that the intrahepatic antibodies reacted against HBcAg, consistent with the extensive HBcAg mutations and with the significantly higher titers of serum IgM anti-HBc seen in ALF than acute hepatitis B.