A type I interferon regulatory network for human plasmacytoid dendritic cells based on heparin, membrane-bound and soluble BDCA-2

Plasmacytoid dendritic cells (pDCs) produce type I interferons (IFNs) after sensing viral/bacterial RNA or DNA by toll-like receptor (TLR) 7 or TLR9, respectively. However, aberrant pDCs activation can cause adverse effects on the host and contributes to the pathogenesis of type I IFN-related autoimmune diseases. Here, we show that heparin interacts with the human pDCs-specific blood dendritic cell antigen 2 (BDCA-2) but not with related lectins such as DCIR or dectin-2. Importantly, BDCA-2-heparin interaction depends on heparin sulfation and receptor glycosylation and results in inhibition of TLR9-driven type I IFN production in primary human pDCs and the pDC-like cell line CAL-1. This inhibition is mediated by unfractionated and low-molecular-weight heparin, as well as endogenous heparin from plasma, suggesting that the local blood environment controls the production of IFN-α in pDCs. Additionally, we identified an activation-dependent soluble form of BDCA-2 (solBDCA-2) in human plasma that functions as heparin antagonist and thereby increases TLR9-driven IFN-α production in pDCs. Of importance, solBDCA-2 levels in the serum were increased in patients with scrub typhus (an acute infectious disease caused by Orientia tsutsugamushi) compared to healthy control subjects and correlated with anti-dsDNA antibodies titers. In contrast, solBDCA-2 levels in plasma from patients with bullous pemphigoid or psoriasis were reduced. In summary, this work identifies a regulatory network consisting of heparin, membrane-bound and solBDCA-2 modulating TLR9-driven IFN-α production in pDCs. This insight into pDCs function and regulation may have implications for the treatment of pDCs-related autoimmune diseases.

Coupling of a Major Allergen to the Surface of Immune Cells for Use in Prophylactic Cell Therapy for the Prevention of IgE-Mediated Allergy

Up to a third of the world's population suffers from allergies, yet the effectiveness of available preventative measures remains, at large, poor. Consequently, the development of successful prophylactic strategies for the induction of tolerance against allergens is crucial. In proof-of-concept studies, our laboratory has previously shown that the transfer of autologous hematopoietic stem cells (HSC) or autologous B cells expressing a major grass pollen allergen, Phl p 5, induces robust tolerance in mice. However, eventual clinical translation would require safe allergen expression without the need for retroviral transduction. Therefore, we aimed to chemically couple Phl p 5 to the surface of leukocytes and tested their ability to induce tolerance. Phl p 5 was coupled by two separate techniques, either by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) or by linkage via a lipophilic anchor, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol)-maleimide (DSPE-PEG-Mal). The effectiveness was assessed in fresh and cultured Phl p 5-coupled cells by flow cytometry, image cytometry, and immunofluorescence microscopy. Chemical coupling of Phl p 5 using EDC was robust but was followed by rapid apoptosis. DSPE-PEG-Mal-mediated linkage was also strong, but antigen levels declined due to antigen internalization. Cells coupled with Phl p 5 by either method were transferred into autologous mice. While administration of EDC-coupled splenocytes together with short course immunosuppression initially reduced Phl p 5-specific antibody levels to a moderate degree, both methods did not induce sustained tolerance towards Phl p 5 upon several subcutaneous immunizations with the allergen. Overall, our results demonstrate the successful chemical linkage of an allergen to leukocytes using two separate techniques, eliminating the risks of genetic modifications. More durable surface expression still needs to be achieved for use in prophylactic cell therapy protocols.

Determination of the caffeine contents of various food items within the Austrian market and validation of a caffeine assessment tool (CAT)

The caffeine content of 124 products, including coffee, coffee-based beverages, energy drinks, tea, colas, yoghurt and chocolate, were determined using RP-HPLC with UV detection after solid-phase extraction. Highest concentrations of caffeine were found for coffee prepared from pads (755 mg l⁻¹) and regular filtered coffee (659 mg l⁻¹). The total caffeine content of coffee and chocolate-based beverages was between 15 mg l⁻¹ in chocolate milk and 448 mg l⁻¹ in canned ice coffee. For energy drinks the caffeine content varied in a range from 266 to 340 mg l⁻¹. Caffeine concentrations in tea and ice teas were between 13 and 183 mg l⁻¹. Coffee-flavoured yoghurts ranged from 33 to 48 mg kg⁻¹. The caffeine concentration in chocolate and chocolate bars was between 17 mg kg⁻¹ in whole milk chocolate and 551 mg kg⁻¹ in a chocolate with coffee filling. A caffeine assessment tool was developed and validated by a 3-day dietary record (r²= 0.817, p < 0.01) using these analytical data and caffeine saliva concentrations (r²= 0.427, p < 0.01).

Effect of 2-mercapto-ethanol on some brain biochemical characteristics and behavioural changes in the ageing CBA/Ca mice

Male CBA/Ca inbred mice were treated with a dose of 8 micrograms 2-mercapto-ethanol per animal per day in the drinking water from the age of 5 months onwards up to the age of 24 months. Dopamine release was greatly decreased in old animals in contrast to the elevation of dopamine release in the treated mice. Similarly, an elevated malondialdehyde content in brain homogenates was also observed in the aged treated animals compared with their controls. No essential differences were observed in locomotor activity and learning between treated an control mice.

Adaptive changes in the central noradrenergic system in monocular deprived rats

Noradrenaline and dopamine content, K+-stimulated release of 3H-noradrenaline, 3H-noradrenaline high-affinity uptake, 3H-prazosin and 3H-rauwolscine binding to alpha 1- and alpha 2-adrenoreceptors, respectively, were studied in isolated visual structures (visual cortex, superior colliculus, lateral geniculate nucleus) of three-month-old rats monocularly deprived by unilateral eyelid closure at postnatal day 11. Monocular deprivation resulted in a number of changes in comparison with normal littermates, mainly in the lateral geniculate nucleus, both ipsilateral and contralateral to the closed eye. K+-stimulated release of noradrenaline and high-affinity noradrenaline uptake were significantly increased, 3H-rauwolscine binding to alpha 2-adrenergic receptor sites was decreased in the contralateral and ipsilateral lateral geniculate nucleus. 3H-Prazosin binding to alpha 1-adrenergic receptors as well as the levels or noradrenaline and dopamine in the lateral geniculate nucleus were unaffected by monocular deprivation. The data support the suggestion that the lateral geniculate nucleus plays a key role in modulating visual information processing and that the lack of an adequate visual input within the first weeks of life interferes mainly with the development of the noradrenergic system at the level of the lateral geniculate nucleus.

[Characterization of functional disorders of bone marrow by measuring chemiluminescence]

It is reported on first experiences with measurements of chemiluminescence on the bone marrow. Suspensions of the bone marrow show a spontaneous chemiluminescence which can be stimulated by Zymosan. Haematological diseases and changes of the bone marrow under influence of the cytostatic therapy react on the behaviour of chemiluminescence. The size of the changes possibly allows of conclusions to the behaviour of the regeneration of the bone marrow.

Measurement of the postruminal digestibility of crude protein by the bag technique in cows

A new method has been developed which permits the crude protein digestibility of feedstuffs in the intestine of cattle to be measured with little effort in terms of samples and experimental work. It consists of welding 0.4 ... 0.8 g of the feedstuff (particle size: 125 ... 1000 micron) into polyamide fabric bags (25 X 40 mm) which are inserted via cannulae into the digestive tracts of fistulated cows from the abomasum/duodenum to the ileum or from the abomasum/duodenum to the faeces. The mean retention time of the bags in the animal was 8.5 +/- 2.7 h from the abomasum to the end of the ileum and (13.3 +/- 1.9 h from the abomasum to the faeces. Up to 15 bags per day and cow may be used. The random error of the method is 1.3% (absolute) when the measurements are performed on two animals using two bags each. Intestinal digestibilities of over 90% were measured for concentrate proteins (except linseed meal) and of 72 ... 95% for forage proteins. Post-ruminal digestion was virtually finished at the end of the small intestine.

[Therapeutic possibilities of influencing brain oedema by the action of glycerin (author's transl)]

The action of glycerin on brain oedema is reported and we also point out its effectiveness as a dehydrating agent, not only in the sphere of brain oedeme (animal experiments) but also in cerebral tumours.

The influence of haloperidol pretreatment on the morphine toxicity

The influence of dopaminergic modifiers on morphine-induced analgesia and lethality was studied comparing both the effect of a single pre-dose of haloperidol and and continuous pretreatment for three weeks with haloperidol. A single administration of haloperidol enhanced morphine-induced analgesia probably due to the receptor blocking action of haloperidol which supports the reduction of dopamine release produced by morphine. The daily haloperidol administration for 3 weeks however decreased the analgesic action of morphine in consequence of a dopamine receptor supersensitivity developed in this time. The lethality was increased under both conditions. These results suggest that the dopaminergic system, dependent upon its sensitivity, plays a modulating role in morphine-induced analgesia, but not in morphine-induced lethality.

[The protochlorophyll(ide) transformation and its relation to the photooxidation of ascorbic acid in etiolated seedlings]

The terminal steps in chlorophyll synthesis leading from protochlorophyll(ide) to chlorophyll have been investigated on etiolated seedlings of Triticum vulgare.It could be demonstrated that at least before the lag-phase the synthesis of chlorophyll proceeds not only via protochlorophyllide but also via protochlorophyll; however, about 90% of the synthesized chlorophyll originates from protochlorophyllide reduction.By a two-minute illumination with 7000 Lux 76-88% of the protochlorophyllide but only 30-60% of the protochlorophyll is transformed into chlorophyll(ide).As to the question of the hydrogen donor for this transformation, the present investigations have revealed that in red light the protochlorophyll(ide) reduction corresponds to the photooxidation of ascorbic acid. Hence it is suggested that in the photoreduction in vivo ascorbic acid could be involved as a reductant for the pigment. This supposition offers a new interpretation of the role of ascorbic acid in the chloroplasts.