Oviduct-specific expression of tissue plasminogen activator in laying hens

Egg-laying hens are important candidate bioreactors for pharmaceutical protein production because of the amenability of their eggs for protein expression. In this study, we constructed an oviduct-specific vector containing tissue plasminogen activator (tPA) protein and green fluorescent protein (pL-2.8OVtPAGFP) and assessed its expression in vitro and in vivo. Oviduct epithelial and 3T3 cells were cultured and transfected with pL-2.8OVtPAGFP and pEGP-N1 (control vector), respectively. The pL-2.8OVtPAGFP vector was administered to laying hens via a wing vein and their eggs and tissues were examined for tPA expression. The oviduct-specific vector pL-2.8OVtPAGFP was expressed only in oviduct epithelial cells whereas pEGP-N1 was detected in oviduct epithelial and 3T3 cells. Western blotting detected a 89 kDa band corresponding to tPA in egg white and oviduct epithelial cells, thus confirming expression of the protein. The amount of tPAGFP in eggs ranged 9 to 41 ng/mL on the third day after vector injection. The tPA expressed in egg white and oviduct epithelial cells showed fibrinolytic activity, indicating that the protein was expressed in active form. GFP was observed only in oviducts, with no detection in heart, muscle, liver and intestine. This is the first study to report the expression of tPA in egg white and oviduct epithelial cells using an oviduct-specific vector

Globalization and Health: developing the journal to advance the field

Founded in 2005, Globalization and Health was the first open access global health journal. The journal has since expanded the field, and its influence, with the number of downloaded papers rising 17-fold, to over 4 million. Its ground-breaking papers, leading authors -including a Nobel Prize winner- and an impact factor of 2.25 place it among the top global health journals in the world. To mark the ten years since the journal’s founding, we, members of the current editorial board, undertook a review of the journal’s progress over the last decade. Through the application of an inductive thematic analysis, we systematically identified themes of research published in the journal from 2005 to 2014. We identify key areas the journal has promoted and consider these in the context of an existing framework, identify current gaps in global health research and highlight areas we, as a journal, would like to see strengthened