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NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2018

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Sammendrag

Hepatitis B Virus (HBV) infection can be prevented by vaccination. Vaccines containing the small (S)envelope protein are currently used in universal vaccination programs and achieve protective immuneresponse in more than 90% of recipients. However, new vaccination strategies are necessary for successfulimmunization of the remaining non- or low-responders. We have previously characterized a novel HBVchimeric antigen, which combines neutralization epitopes of the S and the preS1 domain of the large (L)envelope protein (genotype D). The S/preS121–47chimera produced in mammalian cells and Nicotianabenthamiana plants, induced a significantly stronger immune response in parenterally vaccinated micethan the S protein. Here we describe the transient expression of the S/preS121–47antigen in an edibleplant, Lactuca sativa, for potential development of an oral HBV vaccine. Our study shows that oral admin-istration of adjuvant-free Lactuca sativa expressing the S/preS121–47antigen, three times, at 1lg/dose,was sufficient to trigger a humoral immune response in mice. Importantly, the elicited antibodies wereable to neutralize HBV infection in an NTCP-expressing infection system (HepG2-NTCP cell line) moreefficiently than those induced by mice fed on Lactuca sativa expressing the S protein. These results sup-port the S/preS121–47antigen as a promising candidate for future development as an edible HBV vaccine.

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Peatlands store substantial amounts of carbon and are vulnerable to climate change. We present a modified version of the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model for simulating the hydrology, surface energy, and CO2 fluxes of peatlands on daily to annual timescales. The model includes a separate soil tile in each 0.5° grid cell, defined from a global peatland map and identified with peat-specific soil hydraulic properties. Runoff from non-peat vegetation within a grid cell containing a fraction of peat is routed to this peat soil tile, which maintains shallow water tables. The water table position separates oxic from anoxic decomposition. The model was evaluated against eddy-covariance (EC) observations from 30 northern peatland sites, with the maximum rate of carboxylation (Vcmax) being optimized at each site. Regarding short-term day-to-day variations, the model performance was good for gross primary production (GPP) (r2 =  0.76; Nash–Sutcliffe modeling efficiency, MEF  =  0.76) and ecosystem respiration (ER, r2 =  0.78, MEF  =  0.75), with lesser accuracy for latent heat fluxes (LE, r2 =  0.42, MEF  =  0.14) and and net ecosystem CO2 exchange (NEE, r2 =  0.38, MEF  =  0.26). Seasonal variations in GPP, ER, NEE, and energy fluxes on monthly scales showed moderate to high r2 values (0.57–0.86). For spatial across-site gradients of annual mean GPP, ER, NEE, and LE, r2 values of 0.93, 0.89, 0.27, and 0.71 were achieved, respectively. Water table (WT) variation was not well predicted (r2 < 0.1), likely due to the uncertain water input to the peat from surrounding areas. However, the poor performance of WT simulation did not greatly affect predictions of ER and NEE. We found a significant relationship between optimized Vcmax and latitude (temperature), which better reflects the spatial gradients of annual NEE than using an average Vcmax value.