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

Crystal Structures Reveal the Multi-Ligand Binding Mechanism of Staphylococcus aureus ClfB

Staphylococcus aureus (S. aureus) pathogenesis is a complex process involving a diverse array of extracellular and cell wall components. ClfB, an MSCRAMM (Microbial Surface Components Recognizing Adhesive Matrix Molecules) family surface protein, described as a fibrinogen-binding clumping factor, is a key determinant of S. aureus nasal colonization, but the molecular basis for ClfB-ligand recognition remains unknown. In this study, we solved the crystal structures of apo-ClfB and its complexes with fibrinogen α (Fg α) and cytokeratin 10 (CK10) peptides. Structural comparison revealed a conserved glycine-serine-rich (GSR) ClfB binding motif (GSSGXGXXG) within the ligands, which was also found in other human proteins such as Engrailed protein, TCF20 and Dermokine proteins. Interaction between Dermokine and ClfB was confirmed by subsequent binding assays. The crystal structure of ClfB complexed with a 15-residue peptide derived from Dermokine revealed the same peptide binding mode of ClfB as identified in the crystal structures of ClfB-Fg α and ClfB-CK10. The results presented here highlight the multi-ligand binding property of ClfB, which is very distinct from other characterized MSCRAMMs to-date. The adherence of multiple peptides carrying the GSR motif into the same pocket in ClfB is reminiscent of MHC molecules. Our results provide a template for the identification of other molecules targeted by S. aureus during its colonization and infection. We propose that other MSCRAMMs like ClfA and SdrG also possess multi-ligand binding properties

ЭВОЛЮЦИЯ ПРОГРАММЫ ТРАНСПЛАНТАЦИИ ПЕЧЕНИ В РОССИЙСКОМ НАУЧНОМ ЦЕНТРЕ РАДИОЛОГИИ И ХИРУРГИЧЕСКИХ ТЕХНОЛОГИЙ

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LIVER TRANSPLANTATION. A SINGLE CENTER EXPERIENCE OF 100 CASES

A single center experience of first 100 liver transplantations (LTs) is summarized. Analysis of trends in cadaver donor population and waiting list status changes, and also of early and late postoperative complications are presented. 100 LTs were performed for 95 patients (pts), retransplantation – 4 pts; one patient received 3 liver transplants (female – 55 pts, male – 40 pts, mean age – 39.9 ± 12.1 years). Cumulative 1-year survival rate of pts by Kaplan–Meyer was 91%, 3-year – 83%. Biliary complications were revealed in 9% of pts during 2–9 months after LT. 77 pts have been regularly observed in outpatient clinic, mean age – 44 ± 9.2 years, male – 35, fema- le – 42, follow-up period – 1 months up to 13 years after LT. 3.9% remained invalid with limitation of ability to work, 61.8% have been working, 22.3% were capable to work, retirees were 10.5%. Development of preoperati- ve planning, adequate organ selection will allow to improve the results of LT. Study of hematopoietic stem cells role will expand tools of prognosis of posttransplant complications