Influenza virus infection is a global public health issue. The effectiveness of antiviral therapies for influenza has been limited by the emergence of drug-resistant viral strains. Therefore, there is an urgent need to identify novel antiviral therapies. Here we tested the effects of 300 traditional Chinese medicines on the replication of various influenza virus strains in a lung cell line, A549, using an influenza-specific luciferase reporter assay. Of the traditional medicines tested, Polygonum cuspidatum (PC) and its active components, resveratrol and emodin, were found to attenuate influenza viral replication in A549 cells. Furthermore, they preferentially inhibited the replication of influenza A virus, including clinical strains isolated in 2009 and 2011 in Taiwan and the laboratory strain A/WSN/33 (H1N1). In addition to inhibiting the expression of hemagglutinin and neuraminidase, PC, emodin, and resveratrol also increased the expression of interferon beta (IFN-β) through Toll-like receptor 9 (TLR9). Moreover, the anti-viral activity of IFN-β or resveratrol was reduced when the A549 cells were treated with neutralizing anti-IFN-β antibodies or a TLR9 inhibitor, suggesting that IFN-β likely acts synergistically with resveratrol to inhibit H1N1 replication. This potential antiviral mechanism, involving direct inhibition of virus replication and simultaneous activation of the host immune response, has not been previously described for a single antiviral molecule. In conclusion, our data support the use of PC, resveratrol or emodin for inhibiting influenza virus replication directly and via TLR-9–induced IFN-β production.

Hepatitis B virus (HBV) infection can cause a wide spectrum of sequelae, ranging from asymptomatic chronic infection to chronic active hepatitis. Three hundred million people around the world are chronically infected with HBV (38, 39). Clinically, it is estimated that 5 to 10% of HBV-infected adults will develop chronic hepatitis (CH) and will thus be at a higher (Ͼ100 times) risk of developing hepatocellular carcinoma (HCC) (1,12,41). Several viral and host factors have been suggested to be involved in the chronicity and diversity of HBV-associated disease (25, 43). The association, at the molecular level, between HBV infection and HBV-related diseases remains unclear.The small, 3.2-kb DNA genome of HBV contains four known open reading frames, called S, C, P, and X. The hepatitis B virus X (HBx) gene is the smallest, with a length of 465 nucleotides (10). HBx protein is 154 amino acids long, with a molecular weight (MW) of 17,000, and is conserved among all mammalian hepadnaviruses, but the deduced amino acid sequence of the HBx gene product does not correspond to any known viral proteins (26). Although the HBx protein has been shown to stimulate cell cycle progression of quiescent cells (18), it is mainly a pleiotropic transactivator, due to its ability to stimulate not only the HBV promoter and enhancer (28, 33) but also a wide range of other viral promoters (33,35,40). The necessity for HBx gene expression during the viral life cycle, in vitro and in vivo, has been suggested (3, 44). The HBx protein acts either through interaction with other cellular transcription factors or via a signal transduction pathway controlled by protein kinase C (15, 30, 31). As a consequence of its activity, the HBx protein appears capable of inducing transformation (32) and liver tumors in a selected strain of mice that express the HBx protein from a transgene (16,17).During the natural course of HBV infection, the HBx gene expresses a polypeptide, HBx, that is implicated in HBV-mediated HCC (4, 16). When liver tissue samples from HCC and CH patients were reacted with an anti-HBx antibody and evaluated by immunohistochemistry, reactive antigen was detected in 80% of HCC liver samples and 30% of CH liver samples (4). In another study, the sera of patients with acute hepatitis, CH, and cirrhosis were tested for HBx protein and anti-HBx antibodies by an enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody and recombinant HBx protein.The results indicated that 23% of patients' sera were HBx positive and 14% of patients' sera were anti-HBx positive (20). In another approach, using HBx oligopeptides as antigens to detect antibodies in the sera of HCC patients, 73% of HCC sera tested positive for anti-HBx antibodies (27). With similar approaches, data showed that 74% of sera from patients with cirrhosis and 54% of sera from patients with HCC were positive for anti-HBx antibodies and HBV surface antigen (HBs) (36). Therefore, the expression of HBx protein in infected patients did not correlate well with the occurrence of...

Hemophagocytic lymphohistiocytosis (HLH), presenting with fever, cytopenia, liver dysfunction, hepatosplenomegaly, hypertriglyceridemia, and hyperferritinemia, is associated with various etiologies, including infections, collagen vascular diseases, and malignancies. The present report describes a 28-year-old woman who developed HLH combined with autoimmune hemolytic anemia (AIHA) at 23 weeks of gestation. Without response to corticosteroid, the patient completely recovered from both HLH and AIHA after termination of the pregnancy. Pregnancy-induced immune dysregulation and cytokine overproduction in genetically susceptible women may play critical roles in HLH. The differential diagnosis of pregnant women with fever and cytopenia should include HLH. Pregnancy termination should be considered when pregnancy-induced HLH is refractory to medical treatment.

For expression of Bacillus stearothermophilus NCIB 8924 leucine aminopeptidase II (LAP II) in Escherichia coli regulated by a T5 promoter, the gene was amplified by polymerase chain reaction and cloned into expression vector pQE-32 to generate pQE-LAPII. The His(6)-tagged enzyme was overexpressed in IPTG-induced E. coli M15 (pQE-LAPII) as a soluble protein and was purified to homogeneity by nickel-chelate chromatography to a specific activity of 425 U/mg protein with a final yield of 76%. The subunit molecular mass of the purified protein was estimated to be 44.5 kDa by SDS-PAGE. The temperature and pH optima for the purified protein were 60 degrees C and 8.0, respectively. Under optimal condition, the purified enzyme showed a marked preference for Leu- p-nitroanilide, followed by Arg- and Lys-derivatives. The His(6)-tagged enzyme was stimulated by Co(2+) ions, but was strongly inhibited by Cu(2+) and Hg(2+) and by the chelating agents, DTT and EDTA. The EDTA-treated enzyme could be reactivated with Co(2+) ions, indicating that it is a cobalt-dependent exopeptidase. Taking the biochemical characteristics together, we found that the recombinant LAP II exhibits no important differences from those properties described for the native enzyme.

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