Recombinant barley-produced antibody for detection and immunoprecipitation of the major bovine milk allergen, ß-lactoglobulin.

Recombinant allergens and antibodies are needed for diagnostic, therapeutic, food processing and quality verification purposes. The aim of this work was to develop a barley-based production system for ß-lactoglobulin (BLG) specific immunoglobulin E antibody (D1 scFv). The expression level in the best barley cell clone was 0.8-1.2 mg/kg fresh weight, and was constant over an expression period of 21 days. In the case of barley grains, the highest stable productivity (followed up to T2 grains) was obtained when the D1 scFv cDNA was expressed under a seed-specific Glutelin promoter rather than under the constitutive Ubiquitin promoter. Translational fusion of ER retention signal significantly improved the accumulation of recombinant antibody. Furthermore, lines without ER retention signal lost D1 scFv accumulation in T2 grains. Pilot scale purification was performed for a T2 grain pool (51 g) containing 55.0 mg D1 scFv/kg grains. The crude extract was purified by a two-step purification protocol including IMAC and size exclusion chromatography. The purification resulted in a yield of 0.47 mg of D1 scFv (31 kD) with high purity. Enzyme-linked immunosorbent assay revealed that 29 % of the purified protein was fully functional. In immunoprecipitation assay the purified D1 scFv recognized the native 18 kD BLG in the milk sample. No binding was observed with the heat-treated milk sample, as expected. The developed barley-based expression system clearly demonstrated its potential for application in the processing of dairy milk products as well as in detecting allergens from foods possibly contaminated by bovine milk.

F4 (K88) fimbrial adhesin FaeG expressed in alfalfa reduces F4+ enterotoxigenic Escherichia coli excretion in weaned piglets.

Transgenic plants are attractive bioreactors to large-scale production of recombinant proteins because of their relatively low cost. This study reports for the first time the use of transgenic plants to reduce enterotoxigenic Escherichia coli (ETEC) excretion in its natural host species. The DNA sequence encoding the major subunit and adhesin FaeG of F4+ ETEC was transformed into edible alfalfa plants. Targeting of FaeG production to chloroplasts led to FaeG levels of up to 1% of the total soluble protein fraction of the transgenic alfalfa. Recombinant plant-produced FaeG (pFaeG) remained stable for 2 years when the plant material was dried and stored at room temperature. Intragastric immunization of piglets with pFaeG induced a weak F4-specific humoral response. Co-administration of pFaeG and the mucosal adjuvant cholera toxin (CT) enhanced the immune response against FaeG, reflected a better induction of an F4-specific immune response. In addition, the intragastric co-administration of CT with pFaeG significantly reduced F4+ E. coli excretion following F4+ ETEC challenge as compared with pigs that had received nontransgenic plant material. In conclusion, transgenic plants producing the FaeG subunit protein could be used for production and delivery of oral vaccines against F4+ ETEC infections.

Berry phenolics selectively inhibit the growth of intestinal pathogens.

AIMS: To investigate the effects of berries and berry phenolics on pathogenic intestinal bacteria and to identify single phenolic compounds being responsible for antimicrobial activity. METHODS AND RESULTS: Antimicrobial activity of eight Nordic berries and their phenolic extracts and purified phenolic fractions were measured against eight selected human pathogens. Pathogenic bacterial strains, both Gram-positive and Gram-negative, were selectively inhibited by bioactive berry compounds. Cloudberry and raspberry were the best inhibitors, and Staphylococcus and Salmonella the most sensitive bacteria. Phenolic compounds, especially ellagitannins, were strong inhibitory compounds against Staphylococcus bacteria. Salmonella bacteria were only partly inhibited by the berry phenolics, and most of the inhibition seemed to originate from other compounds, such as organic acids. Listeria strains were not affected by berry compounds, with the exception of cranberry. Phenolic compounds affect the bacteria in different mechanisms. CONCLUSIONS: Berries and their phenolics selectively inhibit the growth of human pathogenic bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Antimicrobial properties of berries could be utilized in functional foods. Furthermore these compounds would be of high interest for further evaluation of their properties as natural antimicrobial agents for food and pharmaceutical industry.

Quercetin derivatives are deconjugated and converted to hydroxyphenylacetic acids but not methylated by human fecal flora in vitro.

By using a batch in vitro anaerobic fecal fermentation model, we have shown that the fecal microflora can rapidly deconjugate rutin, isoquercitrin, and a mixture of quercetin glucuronides. High levels of beta,D-glucosidase, alpha,L-rhamnosidase, and beta,D-glucuronidase were present. Rutin underwent deglycosylation, ring fission, and dehydroxylation. The main metabolite, 3,4-dihydroxyphenylacetic acid, appeared rapidly (2 h) and was dehydroxylated to 3-hydroxyphenylacetic acid within 8 h. The pattern of in vitro fermentation of rutin was not changed by changing the pH (6.0 or 6.9), fermentation scale (10 or 1000 mL), or donors of the inoculum. Hydroxyphenylacetic acids were not methylated by colon flora in vitro. The colonic microflora has enormous potential to transform flavonoids into lower molecular weight phenolics, and these might have protective biological activities in the colon. The site of absorption of flavonoids and the form in which they are absorbed are critical for determining their metabolic pathway and consequent biological activities in vivo.

Antimicrobial properties of phenolic compounds from berries.

AIMS: To investigate the antimicrobial properties of phenolic compounds present in Finnish berries against probiotic bacteria and other intestinal bacteria, including pathogenic species. METHODS AND RESULTS: Antimicrobial activity of pure phenolic compounds representing flavonoids and phenolic acids, and eight extracts from common Finnish berries, was measured against selected Gram-positive and Gram-negative bacterial species, including probiotic bacteria and the intestinal pathogen Salmonella. Antimicrobial activity was screened by an agar diffusion method and bacterial growth was measured in liquid culture as a more accurate assay. Myricetin inhibited the growth of all lactic acid bacteria derived from the human gastrointestinal tract flora but it did not affect the Salmonella strain. In general, berry extracts inhibited the growth of Gram-negative but not Gram-positive bacteria. These variations may reflect differences in cell surface structures between Gram-negative and Gram-positive bacteria. Cloudberry, raspberry and strawberry extracts were strong inhibitors of Salmonella. Sea buckthorn berry and blackcurrant showed the least activity against Gram-negative bacteria. CONCLUSION: Different bacterial species exhibit different sensitivities towards phenolics. SIGNIFICANCE AND IMPACT OF THE STUDY: These properties can be utilized in functional food development and in food preservative purposes.

Factors affecting the regeneration capacity of isolated barley microspores (Hordeum vulgare L.).

The culture of isolated microspores of barley (Hordeum vulgare L. cv. Kymppi, an elite malting barley cultivar) was studied. A careful choice of culture steps resulted in an average regeneration frequency of 300 green plants per starting material spike. Strong seasonal variation in regeneration capacity was observed. The choice of a cold pretreatment method affected the viability of microspores. A cold pretreatment of the collected starting material at +4°C for 4 weeks was needed for the efficient regeneration of green plants from isolated microspore cultures. Glutamine omission from and copper additions to microspore culture were studied. The omission of glutamine did not affect the number of regenerated green plants but did result in an increase in the number of regenerated albino plants. The addition of copper did not improve the regeneration capacity of isolated barley microspores. Transformation by particle bombardment of isolated microspores did not result in the production of transgenic plants.

Simultaneous determination of scopolamine, hyoscyamine and littorine in plants and different hairy root clones of Hyoscyamus muticus by micellar electrokinetic chromatography.

Hyoscyamus muticus hairy root clones were established following infection with Agrobacterium rhizogenes strains A4, LBA-9402 and 15834 and with A. tumefaciens strain C58C1pRTGus104. The accumulation of tropane alkaloids hyoscyamine, littorine and scopolamine was evaluated by micellar electrokinetic capillary electrophoresis. Littorine was reported for the first time in these clones as well as in the roots of the intact plant and confirmed by collision induced dissociation-mass spectrometry. Tropane alkaloid content in hairy roots was compared with leaves and roots of normal plants at two vegetative stages. Significant differences appeared between the alkaloid contents of the different clones. In particular, all the hairy root clones and the roots of the intact plant produced 1.5-3 and 4.5-9 times more littorine than scopolamine, respectively. The only exception was clone KB7, carrying the h6h gene, which overproduced scopolamine. The aerial parts of H. muticus plants did not contain any littorine, thus indicating different transportation or translocation mechanisms of the various tropane alkaloids.

Jasmonates induce over-accumulation of methylputrescine and conjugated polyamines in Hyoscyamus muticus L. root cultures.

Jasmonic acid (JA) and its methyl ester (MeJA) at concentrations ranging from 0.001 to 10 µM provoked large increases in methylputrescine levels in normal and hairy roots of Hyoscyamus muticus L.; generally, levels of free putrescine and perchloric acid-soluble conjugated putrescine, spermidine and spermine also increased dramatically. More 14C-putrescine was formed when hairy roots were incubated with labelled ornithine than with arginine; conjugated 14C-putrescine was also rapidly formed. In accord with these results, ornithine decarboxylase (EC 4.1.1.17) activity was higher than that of arginine decarboxylase (EC 4.1.1.19), and MeJA enhanced these activities about two- and fourfold, respectively. Although treatment of root cultures with jasmonates enhanced precursor (putrescine, methylputrescine) levels and accumulation of secondary metabolites such as acid-soluble conjugated di-/polyamines, it provoked only modest increases in tropane alkaloid tissue levels.

Determination of the main tropane alkaloids from transformed Hyoscyamus muticus plants by capillary zone electrophoresis.

A capillary zone electrophoretic method (CZE) was developed using an uncoated fused silica capillary for the separation and determination of the main tropane alkaloids. The applicability of the developed method for analysis of plant samples was examined by analyzing samples of transgenic Egyptian henbane Hyoscyamus muticus (L.) plants. A simple 40 mM phosphate buffer at pH 7.8 using a voltage of 20 kV was found the best for this purpose. The main tropane alkaloids, atropine and scopolamine as well as nor-(-)-scopolamine, and tropic acid, the precursor of tropane alkaloids, could be separated in less than 13 min. The linear concentration range for atropine was 5.00-140 microg ml(-1), for scopolamine 7.50-210 microg ml(-1) and for tropic acid 2.50-70.0 microg ml(-1).

Somaclonal variation in transformed roots and protoplast-derived hairy root clones of Hyoscyamus muticus.

Substantial somaclonal variation in growth rate, morphology, and alkaloid production of Hyoscyamus muticus L. hairy root clones obtained by transformation with four Agrobacterium strains was shown. The hyoscyamine content of the root clones (n = 100) obtained from the same origin varied from 0.03 to 0.59% of dry weight. The clones produced 25-320 times less scopolamine than hyoscyamine. The best producing root clone was used as a starting material for protoplast isolation. The hyoscyamine content of protoplast-derived hairy root clones (n = 171) ranged from 0.04 to 1.45 % of dry weight. Most clones showed improved alkaloid production in relation to the parent clone, but the mean hyoscyamine content of the clones was the same as that of the parent clone. All the studied hairy root clones showed relatively stable alkaloid production during long-term cultivation. No correlation was found between alkaloid production and growth rate or morphology of the clones.

Characterization of transgenic plants derived from hairy roots ofHyoscyamus muticus.

Mature plants were regenerated via protoplasts fromAgrobacterium rhizogenes-transformed root cultures ofHyoscyamus muticus L., and chemical analyses were performed on 34 individual plants. The regenerated plants showed strong phenotypic differences from clone to clone as well as from the control plants. Polymerase chain reaction studies revealed that the plants exhibiting the strongest phenotypic alterations contained therol (A, B and C) genes, whereas the plants with fewer alterations had lost them. The plants produced hyoscyamine, scopolamine and a range of different calystegins, and considerable somaclonal variation was observed. Alkaloid production in the plants transgenic for therol genes was clearly reduced. The pattern of calystegins was similar within all the regenerated plants lackingrol genes. Among the plants withrol genes, the calystegin B1 was not detectable. It seems clear that the presence ofrol genes is detrimental to the alkaloid accumulation in the transgenic plants in contrast to hairy root cultures.

Efficient plant regeneration from hairy root-derived protoplasts of Hyoscyamus muticus.

Successful plant regeneration was achieved for the first time from hairy root-derived protoplasts of Hyoscyamus muticus. High yields (7 × 10(6) / g fresh weight) of protoplasts were isolated directly from the transformed roots of Hyoscyamus muticus using an enzyme mixture comprising 1 % macerozyme and 2 % cellulase in an osmoticum consisting of 0.2 M CaCl2 and 0.6 M mannitol. Protoplasts were first cultured in liquid NT/PRO I medium and further on semi-solid NT/PRO II agar medium. The procedure permits highly efficient formation of colonies. The plating efficiency varied from 1-9 %. The small individual colonies regenerated easily into shoots and roots at frequencies of 18 % and 70 %, respectively. The time required for the development of small plantlets from protoplasts was 8-11 weeks. The regenerated plants contained rolB from Ri-T-DNA and exhibited an altered phenotype compared to the control plants.

Virulence of different Agrobacterium strains on hairy root formation of Hyoscyamus muticus.

Hyoscyamus muticus accession was evaluated for its response to inoculation with Agrobacterium rhizogenes strains LBA9402, A4, 15834, and Agrobacterium tumefaciens strain C58 CI pRT GUS104. The Agrobacterium strain used for the transformation has a significant influence on the phenotype of the clone as well as on the growth rate and hyoscyamine production of these root culture clones. The most virulent strains were C58 CI pRT GUS104 and LBA9402. More roots were obtained on LSO medium than on B50 medium. Acetosyringone addition and the time from wounding affected root formation. The alkaloid content was highest in clones C58 and A4 (≈90mg·l(-1)). There are great differences between individual hairy root clones, and hence they are not as uniform as has often been speculated. The Agrobacterium strain used for the transformation has a great influence in this respect.

Spontaneous somatic embryogenesis and plant regeneration from root cultures of Peucedanum palustre.

The regeneration of Peucedanum palustre (L.) Moench (milk parsley) was established for the first time via somatic embryogenesis from primary root cultures. Callus formation occurred on the root cultures and showed spontaneous embryogenic capability on B5 basal medium supplemented with a low concentration of indoleacetic acid (5.5 × 10(-7) M). 2,4-Dichlorophenoxyacetic acid was not needed for the initiation of embryogenesis. The somatic embryos germinated and formed plantlets on hormone-free B5 medium. These plantlets were easily transferable to pots, and are presently passing their second growing season in the greenhouse.Development of the somatic embryos progressed through the globular, heart-shaped, torpedo-shaped, and cotyledonary stages, typical of zygotic embryos. Synchronization performed by sieving the embryos did not affect the development time. The culture has retained its embryogenic capacity for 25 months.

Analysis of tropane alkaloids with thermospray high-performance liquid chromatography-mass spectrometry.

A thermospray high-performance liquid chromatography-mass spectrometry method for analysis of hyoscyamine and scopolamine in plant cell culture samples is described. The alkaloids were separated on a polymeric reversed-phase column with an alkaline ammonium acetate buffer-acetonitrile eluent. Selected-ion recording of the protonated molecular ions was used for quantitation of the compounds. The compounds were fragmented by discharge-assisted ionization and elevated thermospray capillary temperatures or ion repeller potentials.

Variation in the Tropane Alkaloid Content of Hyoscyamus muticus Plants and Cell Culture Clones.

Systematic studies were carried out on two different strains (Gatersleben and Cairo) of HYOSCYAMUS MUTICUS L. (Solananaceae) in order to analyse the variation in the contents of the two main tropa-alkaloids in individual plants and protoplast-derived cell culture clones. The hyoscyamine content was determined by radioimmunoassay, the scopolamine content by radio- and enzymeimmunoassay and the total tropane alkaloid content by quinuclidinyl benzilate assay. The development stage of the plant is important for alkaloid production. Clear maximal foliar scopolamine and hyoscyamine contents were reached at the onset of flowering and during the full blooming stage, respectively. In the roots the changes in the production of these alkaloids were not considerable. Hyoscyamine is a major alkaloid in the plants as well as in the cell culture clones. In a few exceptions the scopolamine content was greater than that of hyoscyamine, but this phenomenon was not inherited by the cultured clones derived from these plants. High and low tropane alkaloid production was inherited by the selfed F (1), generation plants. Great variability in these alkaloids was observed among individual plants or clones in the same plant or clone population. There was a significant difference between the Cairo strain and the Gatersleben strain as regards their ability to produce tropane alkaloids. Haploid plants of both strains contained more hyoscyamine and scopolamine than the diploid ones. Hyoscyamine and scopolamine were the main alkaloids in the clones and in the plants. Via QNB-assay an interesting clone was found which contains remarkable amounts of unknown tropane-group alkaloids.

Pharmacokinetics and clinical effects of scopolamine in caesarean section patients.

A new method (ELISA) was used to evaluate the pharmacokinetics of scopolamine following intravenous (0.005 mg/kg), intramuscular (0.01 mg/kg), and oropharyngeal (0.035 mg/kg) administration of the drug to pregnant patients anaesthetized for caesarean section. After intravenous (N = 4) the drug fast disappeared from the circulation with a half-life of about 5 min., and the serum levels generally were measurable up to 3 hours, mean elimination half-life was 1.85 hours. A fast absorption was found after intramuscular injection, tmax = 10 min. (N = 4), and the drug had a clinically significant oropharyngeal absorption as well, tmax was around 1 hour (N = 6). The intramuscular and oropharyngeal, but not the intravenous, administrations produced a marked postoperative sedative and amnesic effects. All three administration ways caused a significant antisecretory action.