Pi-Han Lin

Virological, Serological, and Antiviral Studies in an Imported Human Case of Avian Influenza A(H7N9) Virus in Taiwan

We describe the clinical course and virological characteristics of the first H7N9 influenza case in a Taiwanese patient; this patient had detectable viruses in the airway for 2 weeks, during which time an oseltamivir resistance-associated R292K mutation rapidly emerged. Anti-H7N9 antibody was detected 21 days after onset of symptoms, when H7N9 viral load declined significantly.

Anti-HSV activity of digitoxin and its possible mechanisms

Herpes simplex virus type 1 (HSV-1) can establish latent infection in the nervous system and usually leads to life-threatening diseases in immunocompromised individuals upon reactivation. Treatment with conventional nucleoside analogue such as acyclovir is effective in most cases, but drug-resistance may arise due to prolonged treatment in immunocompromised individuals. In this study, we identified an in-use medication, digitoxin, which actively inhibited HSV-1 replication with a 50% effective concentration (EC(50)) of 0.05 microM. The 50% cytotoxicity concentration (CC(50)) of digitoxin is 10.66 microM and the derived selective index is 213. Several structural analogues of digitoxin such as digoxin, ouabain octahydrate and G-strophanthin also showed anti-HSV activity. The inhibitory effects of digitoxin are likely to be introduced at the early stage of HSV-1 replication and the virus release stage. The observation that digitoxin can inhibit acyclovir-resistant viruses further implicates that digitoxin represents a novel drug class with distinct antiviral mechanisms from traditional drugs.

Inhibition of HIV-1 Tat-mediated transcription by a coumarin derivative, BPRHIV001, through the Akt pathway.

ABSTRACT The human immunodeficiency virus type 1 (HIV-1)-encoded RNA-binding protein Tat is known to play an essential role in viral gene expression. In the search for novel compounds to inhibit Tat transactivity, one coumarin derivative, BPRHIV001, was identified, with a 50% effective concentration (EC50) against HIV-1 at 1.3 nM. BPRHIV001 is likely to exert its effects at the stage after initiation of RNAPII elongation since Tat protein expression and the assembly of the Tat/P-TEFb complex remained unchanged. Next, a reduction of the p300 protein level, known to modulate Tat function through acetylation, was observed upon BPRHIV001 treatment, while the p300 mRNA level was unaffected. A concordant reduction of phosphorylated Akt, which was shown to be closely related to p300 stability, was observed in the presence of BPRHIV001 and was accompanied by a decrease of phosphorylated PDPK1, a well-known Akt activator. Furthermore, the docking analysis revealed that the reduced PDPK1 phosphorylation likely resulted from the allosteric effect of interaction between BPRHIV001 and PDPK1. With strong synergistic effects with current reverse transcriptase inhibitors, BPRHIV001 has the potential to become a promising lead compound for the development of a novel therapeutic agent against HIV-1 infection.

Increasing Incidence of Recent Hepatitis D Virus Infection in HIV-Infected Patients in an Area Hyperendemic for Hepatitis B Virus Infection

BACKGROUND Superinfection with hepatitis D virus (HDV) may increase the risk for hepatitis flares and chronic hepatic complications in patients with chronic hepatitis B virus (HBV) infection. This retrospective observational study aimed to examine the incidence of and factors associated with recent HDV superinfection among individuals coinfected with human immunodeficiency virus (HIV) and HBV. METHOD Anti-HDV immunoglobulin G (IgG) was sequentially determined in 375 HIV/HBV-coinfected patients to estimate the HDV incidence between 1992 and 2012. Plasma HDV and HBV loads and HBV surface antigen (HBsAg) levels were determined for the HDV seroconverters. A nested case-control study was conducted to identify the associated factors with HDV seroconversion. Phylogenetic analysis was performed using HDV sequences amplified from HDV seroconverters and HDV-seropositive patients at baseline. RESULTS During 1762.4 person-years of follow-up [PYFU], 16 patients seroconverted for HDV, with an overall incidence rate of 9.07 per 1000 PYFU, which increased from 0 in 1992-2001, to 3.91 in 2002-2006, to 13.26 per 1000 PYFU in 2007-2012 (P < .05). Recent HDV infection was associated with elevated aminotransferase and bilirubin levels and elevated rapid plasma reagin titers. Of the 12 patients with HDV viremia, 2 were infected with genotype 2 and 10 with genotype 4. HBsAg levels remained elevated despite a significant decline of plasma HBV DNA load with combination antiretroviral therapy that contained lamivudine and/or tenofovir. CONCLUSIONS Our findings show that the incidence of recent HDV infection in HIV/HBV-coinfected patients increased significantly from 1992-2001 to 2007-2011, and was associated with hepatitis flares and syphilis.

Schinarisanlactone A, a New Bisnortriterpenoid from Schisandra arisanensis

A novel triterpenoid, schinarisanlactone A (1), was isolated from the fruits of Schisandra arisanensis. Compound 1 possesses an unprecedented skeleton having a 5/7/7/5/7/5/6/5-fused octacyclic ring system. The structure of 1 was determined by 2D NMR techniques (COSY, HMQC, HMBC, and NOESY) and was confirmed by X-ray crystallographic analysis. Schinarisanlactone A (1) exhibited significant anti-HIV activity.

Serological survey in close contacts with a confirmed case of H7N9 influenza in Taiwan

The first confirmed case of H7N9 infection outside mainland China has been documented in Taiwan. We followed the close contacts with this confirmed cases by serological determination for hemagglutinin inhibition (HI) activity, to assess the potential of human-to-human transmission of H7N9 virus. The HI assay was performed by a standard procedure according to Manual for the Laboratory Diagnosis and Virological Surveillance of Influenza (WHO, 2011) and using 0.5% turkey erythrocytes and recombinant hemagglutinin (H7N9, A/Anhui/1/2013, Sino Biological Inc., Beijing, P.R. China). This study has been approved by Institutional Review Board, and all subjects have given their written informed consent. A total of 14 close contacts were identified, including his family (n Z 3, unprotected household contact), friends (n Z 2, unprotected contact in golf-playing and having a

Schisarisanlactones A and B: A new class of nortriterpenoids from the fruits of Schisandra arisanensis

Two novel highly oxygenated nortriterpenoids, schisarisanlactones A (1) and B (2), have been isolated from the fruits of Schisandra arisanensis, an endemic plant of Taiwan. Compounds 1 and 2 possess an unprecedented 5/5/7/5/5-fused pentacyclic ring system. The structures of both compounds were determined on the basis of spectroscopic analyses, especially 2D NMR and MS. A plausible biogenetic pathway of 1 was proposed. Schisarisanlactone A (1) showed significant anti-HIV activity.

Prevalence of Integrase Strand Transfer Inhibitors (INSTI) Resistance Mutations in Taiwan

Antiretroviral therapy containing an integrase strand transfer inhibitor (INSTI) plus two NRTIs has become the recommended treatment for antiretroviral-naive HIV-1-infected patients in the updated guidelines. We aimed to determine the prevalence of INSTI-related mutations in Taiwan. Genotypic resistance assays were performed on plasma from ARV-naïve patients (N = 948), ARV-experienced but INSTI-naive patients (N = 359), and raltegravir-experienced patients (N = 63) from 2006 to 2015. Major INSTI mutations were defined according to the IAS-USA list and other substitutions with a Stanford HIVdb score ≧ 10 to at least one INSTI were defined as minor mutations. Of 1307 HIV-1 samples from patients never exposed to INSTIs, the overall prevalence of major resistance mutations to INSTIs was 0.9% (n = 12), with an increase to 1.2% in 2013. Of these 12 sequences, 11 harboured Q148H/K/R, one Y143R, and none N155H. Of 30 sequences (47.6%) with INSTI-resistant mutations from raltegravir-experienced patients, 17 harboured Q148H/K/R, 8 N155H, and 6 Y143C/R. Other than these major mutations, the prevalence of minor mutations were 5.3% and 38.1%, respectively, in ARV-naive and raltegravir-experienced patients. The overall prevalence of INSTI mutations remains low in Taiwan. Surveillance of INSTI resistance is warranted due to circulation of polymorphisms contributing to INSTI resistance and expected increasing use of INSTIs.

Evaluation of performance of human immunodeficiency virus antigen/antibody combination assays in Taiwan.

BACKGROUND The fourth-generation human immunodeficiency virus (HIV) combination assay, which can simultaneously detect the presence of anti-HIV antibody and HIV antigen, has been shown to shorten the window period in HIV diagnosis compared with the third-generation HIV antibody immunoassay. This study was aimed to determine the performance of HIV combination assays in Taiwan, where the HIV-1 seroprevalence is 0.007% and HIV-2 infection has never been reported. METHODS Performance of three fourth-generation HIV Ag/Ab combination assays (Dia.Pro, Wantai, and Bio-Rad) and one third-generation HIV Ab immunoassay (AxSYM HIV 1/2 gO) was assessed. RESULTS A total of 152 specimens, including 86 confirmed HIV-seropositive and 66 HIV-seronegative samples, were used in the study. The sensitivity of four assays varied from 98.8% to 100%, and specificity varied from 98.5% to 100%. Performance of the 75 equivocal samples, the HIV status of which was confirmed later, in terms of negative prediction varied from 81.8% to 87.5%. The Bio-Rad and Dia.Pro assays exhibited higher sensitivity for the detection of p24 antigen among the three fourth-generation HIV combination assays. CONCLUSION The three fourth-generation HIV Ag/Ab combination assays exhibited better sensitivity, specificity, and negative prediction than the third-generation HIV Ab immunoassay.

Abstract 1754: BPR2P001S0, a Coumarin derivative, induced cell cycle arrest in A549 through inhibiting PDPK1 activity

Lung cancer is one of the most common causes of cancer deaths in the world, and the emergence of resistant lung cancer cells can lead to treatment failure. The development of new drugs to treat lung cancer, especially those resistant lung cancer cells, is urgent. Previously we identified that coumarin could inhibit replication of human lung cancer A549 cells. The efficacy of 284 coumarin derivatives on human lung cancer A549 cells was examined, and BPR2P001S0 was the most potent compound. BPR2P001S0 exhibited growth inhibition and apoptotic activity on A549 cells with an IC50 of 10 nM. A similar level of inhibitory effects was also observed in cisplatin-resistant A549 cells (IC50 = 12.5 nM). The ability of colony formation and migration capability of A549 cells decreased significantly in the presence of BPR2P001S0. In cell cycle analysis, BPR2P001S0 induced cell cycle arrest at the G0/G1 phase through down-regulation of cyclin D1 and Cdk4 protein expression. The expression of cyclinD1/Cdk4 regulatory protein, Akt, was also decreased. Subsequently, we found that the expression level of Ser241 phosphorated PDPK1 protein, an Akt activator in Akt pathway, was also reduced. By molecular docking analysis, we found that the reduced PDPK1 phosphorylation is likely resulted from the allosteric effect of interactions between BPRHIV001 and PDPK1. In conclusion, our results suggest that the anti-tumor activity of BPR2P001S0 is likely resulting from its ability to interfere with PDPK1 autophosphorylation at Ser241, which leads to reduced Akt protein and subsequent cyclin D1 degradation. Citation Format: Pi-Han Lin, Tzu-Ming Jao, Yu-Lin Hung, Hsing-Pang Hsieh, Ya-Chien Yang, Sui-Yuan Chang. BPR2P001S0, a Coumarin derivative, induced cell cycle arrest in A549 through inhibiting PDPK1 activity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1754. doi:10.1158/1538-7445.AM2015-1754