Recombinant IBV (B/Jilin 20/03) Hemagglutinin [His]

The present study was conducted to determine the antiviral activity of different Cholistani plants growing in the Cholistan Desert, Pakistan. Methanolic extracts of plants were prepared by dissolving air-dried, powdered plants in methanol and later concentrated in a rotary evaporator. The concentrated extracts were dissolved in distilled water and sterilized through filtration. To asses antiviral potential plant extracts were mixed with an equal concentration of a live virus and propagated for 7-11 days in embryonated eggs with appropriate controls. After 48 hours, the allantoic fluids were harvested and hemagglutination assay (HA) was performed for infectious bronchitis virus (IBV) and indirect hemagglutination assay (IHA) for infectious bursal disease virus (IBDV) to determine both virus titer, as well as evaluation of the inhibitory effects of various plant extracts. Almost all selected plant extracts exhibited an antiviral effect varying from plant to plant and manifested through controlling growth of IBV except Solanum surattense. The methanolic extracts of two plants Ochthochloa compressa and Sporobolos icolados, showed a 100% inhibitory effect demonstrated through no viral growth determined by HA assays. Similarly, other plant extracts also showed antiviral activity in the order of HA titer at 8 in case of three plants Haloxylon salicornicum, Neurada procumbens and Salsola baryosma, 16 for Achyranthes aspera, Haloxylon recurvum and Panicum antidotale. The HA values 32 and 64, respectively, for Oxystelma esculentum and Suaeda fruticosa were revealed. In case of anti-IBDV activity, the methanolic extracts of Achyranthes aspera, Haloxylon recurvum, Haloxylon salicornicum, Panicum antidotale, Salsola baryosma, Sporobolos icolados were shown to have the optimal antiviral potential (IHA titer 0). Similarly, extract of Neurada procumbens kept the IHA titer at 2 and Solanum surattense at 4. The extracts of Oxystelma esculentum and Ochthochloa compressa were least effective in controlling multiplication of IBDV and their IHA titer was equal to virus control. Overall, our studies open up new avenues in the development of much needed antivirals, utilizing indigenous resources. (C) 2016 PVJ. All rights reserved.

Cleavage of influenza virus hemagglutinin (HA) by host proteases is essential for virus infectivity. HA of most influenza A and B (IAV/IBV) viruses is cleaved at a monobasic motif by trypsin-like proteases. Previous studies have reported that transmembrane serine protease 2 (TMPRSS2) is essential for activation of H7N9 and H1N1pdm IAV in mice but that H3N2 IAV and IBV activation is independent of TMPRSS2 and carried out by as-yet-undetermined protease(s). Here, to identify additional H3 IAV- and IBV-activating proteases, we used RNA-Seq to investigate the protease repertoire of murine lower airway tissues, primary type II alveolar epithelial cells (AECIIs), and the mouse lung cell line MLE-15. Among 13 candidates identified, TMPRSS4, TMPRSS13, hepsin, and prostasin activated H3 and IBV HAin vitro. IBV activation and replication was reduced in AECIIs fromTmprss2/Tmprss4-deficient mice compared with WT or Tmprss2-deficient mice, indicating that murine TMPRSS4 is involved in IBV activation. Multicycle replication of H3N2 IAV and IBV in AECIIs ofTmprss2/Tmprss4-deficient mice varied in sensitivity to protease inhibitors, indicating that different, but overlapping, sets of murine proteases facilitate H3 and IBV HA cleavages. Interestingly, human hepsin and prostasin orthologs did not activate H3, but they did activate IBV HAin vitro. Our results indicate that TMPRSS4 is an IBV-activating protease in murine AECIIs and suggest that TMPRSS13, hepsin, and prostasin cleave H3 and IBV HA in mice. They further show that hepsin and prostasin orthologs might contribute to the differences observed in TMPRSS2-independent activation of H3 in murine and human airways.