5-HT6 Receptors


10.1371/journal.ppat.1000563 [PMC free article] [PubMed] [CrossRef] [Google Scholar] 41. no direct evidence is usually available to confirm the proposed role of HBV mutations in the pathogenesis of HB-LF so far. In addition, other studies have reported contradictory findings, indicating that there is no obvious link between HBV BCP/preC mutations and the development of LF (9, 10). It also remains mechanistically unclear how HBV BCP/preC mutations impact the development of HB-LF. In general, HBV Cetirizine variants may cause liver damage by a direct cytopathic effect or by indirectly promoting immunopathology. There are a few examples of exacerbation of liver diseases associated with cytopathic HBV variants (11,C15). However, it is currently unknown whether the appearance of HBV variants has any influence on host immune responses which would in turn cause liver damage. In the present study, we characterized HBV isolates from a patient with severe liver disease and recognized two major HBV variants, HBV-SH (SH) and HBV-SH-DPS (SH-DPS), which harbored a number of mutations, including two deletions within the preS regions and hepatitis B computer virus surface antigen (HBsAg) sequences. The variant SH-DPS expressed only a nonexportable SHBsAg with abnormal intracellular accumulation. Both SH and SH-DPS coexisted at a ratio of 1 1 to 4. These two isolates were phenotypically characterized alone or together in different ratios by transient transfection. The results exhibited that this coexistence of SH and SH-DPS at a ratio of 1 1 to 4 increased HBV replication and led to a predominant nuclear localization of HBV core antigen (HBcAg). Using an HBV hydrodynamic injection (HI) mouse model, we found that mice mounted significantly stronger antibody and cytotoxic T lymphocyte (CTL) responses to HBsAg only if SH and SH-DPS were coapplied. Thus, the coexistence of different variants may significantly modulate specific host immune responses and may enhance immune-mediated liver damage under some circumstances, representing a novel mechanism for the immunopathogenesis of HBV contamination. MATERIALS AND METHODS Patient. A 38-year-old male patient from China experienced a history of chronic hepatitis B computer virus contamination for over 30 years. He was positive for HBsAg and the antibody to the hepatitis B e antigen (anti-HBe) and was unfavorable for HBeAg and the antibody to HBsAg (anti-HBs). The patient was diagnosed with HB-LF manifesting as a rise in alanine aminotransferase (ALT) to 283 U/liter along with HBV DNA levels of 106 copies/ml, jaundice (bilirubin, 7.9 mg/dl), and coagulopathy (grade II), complicated within 4 weeks by ascites and encephalopathy. The patient received artificial liver support 3 times as well as other treatments, but the illness worsened precipitously, complicated by hepatic encephalopathy, contamination, and hepatorenal syndrome (Fig. 1). Open in a separate windows FIG 1 Clinical course of the patient with HB-LF. (A) Levels of serum transaminase (ALT and aspartate transaminase [AST]), total Ntrk2 bilirubin (TBIL), and direct bilirubin Cetirizine (DBIL). (B) Prothrombin time (PT), prothrombin time activity percentage (PTA), activated partial thromboplastin time (APTT), and fibrinogen (FIB) levels. The patient gave signed, knowledgeable consent. Sample collection, processing, and storage conformed to the ethical guidelines of the 1975 Cetirizine Declaration of Helsinki as reflected in a prior approval by the institution’s human research committee. Characterization of HBV isolates from individual serum samples and cloning. Isolation of HBV viral DNA from individual serum samples was performed as explained previously with minor modifications (16, 17). A PCR was performed to amplify a 2.1-kb fragment (bp 1821 to 699) and a 1.2-kb fragment (bp 669 to 1825) with the primer pairs P1/P3 and P2/P4, respectively: P1, 5-CCGGCGTCGACGAGCTCTTCTTTTTCACCTCTGCCTAATCA-3 (nucleotides [nt] 1821 to 1841); P2, 5-CCGGCGTCGACGAGCTCTTCAAAAAGTTGCATGGTGCTGG-3 (nt 1825 to 1806); P3, 5-CACTGAACAAATGGCACTAGTAAACTGAGCC-3 (nt 699 to 669);.