Monitoring regional astrocyte diversity by cell type-specific proteomic labeling in vivo.

Astrocytes exhibit regional heterogeneity in morphology, function and molecular composition to support and modulate neuronal function and signaling in a region-specific manner. To characterize regional heterogeneity of astrocytic proteomes of different brain regions we established an inducible Aldh1l1-methionyl-tRNA-synthetaseL274G (MetRSL274G ) mouse line that allows astrocyte-specific metabolic labeling of newly synthesized proteins by azidonorleucine (ANL) in vivo and subsequent isolation of tagged proteins by click chemistry. We analyzed astrocytic proteins from four different brain regions by mass spectrometry. The induced expression of MetRSL274G is restricted to astrocytes and identified proteins show a high overlap with proteins compiled in "AstroProt," a newly established database for astrocytic proteins. Gene enrichment analysis reveals a high similarity among brain regions with subtle differences in enriched biological processes and in abundances of key astrocytic proteins for hippocampus, cortex and striatum. However, the cerebellar proteome stands out with proteins being highly associated with the calcium signaling pathway or with bipolar disorder. Subregional analysis of single astrocyte TAMRA intensities in hippocampal layers indicates distinct subregional heterogeneity of astrocytes and highlights the applicability of our toolbox to study differences of astrocytic proteomes in vivo.

Evaluating and expanding the European Union's protected-area network toward potential post-2020 coverage targets.

The Convention on Biological Diversity's (CBD) strategic plan will expire in 2020, but biodiversity loss is ongoing. Scientists call for more ambitious targets in the next agreement. The nature-needs-half movement, for example, has advocated conserving half of Earth to solve the biodiversity crisis, which has been translated to protecting 50% of each ecoregion. We evaluated current protection levels of ecoregions in the territory of one of the CBD's signatories, the European Union (EU). We also explored the possible enlargement of the Natura 2000 network to implement 30% or 50% ecoregion coverage in the EU member states' protected area (PA) network. Based on the most recent land-use data, we examined whether ecoregions have enough natural area left to reach such high coverage targets. We used a spatially explicit mixed integer programing model to estimate the least-cost expansion of the PA network based on 3 scenarios that put different emphasis on total conservation cost, ecological representation of ecosystems, or emphasize an equal share of the burden among member states. To realize 30% and 50% ecoregion coverage, the EU would need to add 6.6% and 24.2%, respectively, of its terrestrial area to its PA network. For all 3 scenarios, the EU would need to designate most recommended new PAs in seminatural forests and other semi- or natural ecosystems. Because 15 ecoregions did not have enough natural area left to implement the ecoregion-coverage targets, some member states would also need to establish new PAs on productive land, allocating the largest share to arable land. Thirty percent ecoregion coverage was met by protecting remaining natural areas in all ecoregions except 3, where productive land would also need to be included. Our results support discussions of higher ecoregions protection targets for post-2020 biodiversity frameworks.

Evaluación y Expansión de la Red de Áreas Protegidas de la Unión Europea hacia Objetivos Potenciales de Cobertura Post 2020 Resumen El plan estratégico del Convenio sobre la Diversidad Biológica (CBD) expirará en 2020, pero la pérdida de la biodiversidad continúa. Los científicos exigen objetivos más ambiciosos para el siguiente acuerdo. Por ejemplo, la corriente la-naturaleza-necesita-la-mitad ha abogado por la conservación de la mitad del planeta para resolver la crisis de la biodiversidad, lo que se ha traducido a la protección del 50% de cada ecoregión. Evaluamos los niveles actuales de protección de las ecoregiones en el territorio de uno de los signatarios de la CBD, la Unión Europea (UE). También exploramos el posible crecimiento de la red Natura 2000 para implementar una cobertura del 30% o 50% de las ecoregiones en la red de áreas protegidas (AP) de los estados miembros de la UE. Con base en los datos más recientes de uso de suelo, examinamos si las ecoregiones todavía tienen suficiente área natural como para alcanzar tales objetivos tan altos de cobertura. Usamos un modelo de programación entera mixta espacialmente explícito para estimar la expansión más asequible de la red de AP con base en tres escenarios que colocan un énfasis diferente sobre el costo total de la conservación, la representación ecológica de los ecosistemas o que enfaticen un porcentaje equitativo de la carga entre los estados miembros. Para alcanzar una cobertura del 30% y 50% de las ecoregiones, la UE necesitaría añadir 6.6% y 24.2%, respectivamente, de su área terrestre a la red de AP. Para los tres escenarios, la UE necesitaría designar la mayoría de las nuevas AP recomendadas en bosques seminaturales y en otros ecosistemas semi- o totalmente naturales. Debido a que 15 ecoregiones no tenían ya suficiente área natural para implementar los objetivos de cobertura de ecoregiones, algunos estados miembros también necesitarían establecer nuevas AP en suelo productivo, asignando la proporción mayor al suelo arable. La cobertura del 30% de las ecoregiones se alcanzó con la protección de las áreas naturales permanecientes en todas las ecoregiones salvo tres, en donde el suelo productivo también necesitaría estar incluido. Nuestros resultados respaldan las discusiones sobre objetivos más altos de protección de ecoregiones para los marcos de trabajo post 2020 para la biodiversidad.

Long-Term Impact of Early-Life Stress on Hippocampal Plasticity: Spotlight on Astrocytes.

Adverse experiences during childhood are among the most prominent risk factors for developing mood and anxiety disorders later in life. Early-life stress interventions have been established as suitable models to study the neurobiological basis of childhood adversity in rodents. Different models such as maternal separation, impaired maternal care and juvenile stress during the postweaning/prepubertal life phase are utilized. Especially within the limbic system, they induce lasting alterations in neuronal circuits, neurotransmitter systems, neuronal architecture and plasticity that are further associated with emotional and cognitive information processing. Recent studies found that astrocytes, a special group of glial cells, have altered functions following early-life stress as well. As part of the tripartite synapse, astrocytes interact with neurons in multiple ways by affecting neurotransmitter uptake and metabolism, by providing gliotransmitters and by providing energy to neurons within local circuits. Thus, astrocytes comprise powerful modulators of neuronal plasticity and are well suited to mediate the long-term effects of early-life stress on neuronal circuits. In this review, we will summarize current findings on altered astrocyte function and hippocampal plasticity following early-life stress. Highlighting studies for astrocyte-related plasticity modulation as well as open questions, we will elucidate the potential of astrocytes as new targets for interventions against stress-induced neuropsychiatric disorders.

Frequency-Comb Spectrum of Periodic-Patterned Signals.

Using arbitrary periodic pulse patterns we show the enhancement of specific frequencies in a frequency comb. The envelope of a regular frequency comb originates from equally spaced, identical pulses and mimics the single pulse spectrum. We investigated spectra originating from the periodic emission of pulse trains with gaps and individual pulse heights, which are commonly observed, for example, at high-repetition-rate free electron lasers, high power lasers, and synchrotrons. The ANKA synchrotron light source was filled with defined patterns of short electron bunches generating coherent synchrotron radiation in the terahertz range. We resolved the intensities of the frequency comb around 0.258 THz using the heterodyne mixing spectroscopy with a resolution of down to 1 Hz and provide a comprehensive theoretical description. Adjusting the electron's revolution frequency, a gapless spectrum can be recorded, improving the resolution by up to 7 and 5 orders of magnitude compared to FTIR and recent heterodyne measurements, respectively. The results imply avenues to optimize and increase the signal-to-noise ratio of specific frequencies in the emitted synchrotron radiation spectrum to enable novel ultrahigh resolution spectroscopy and metrology applications from the terahertz to the x-ray region.

Proper synaptic vesicle formation and neuronal network activity critically rely on syndapin I.

Synaptic transmission relies on effective and accurate compensatory endocytosis. F-BAR proteins may serve as membrane curvature sensors and/or inducers and thereby support membrane remodelling processes; yet, their in vivo functions urgently await disclosure. We demonstrate that the F-BAR protein syndapin I is crucial for proper brain function. Syndapin I knockout (KO) mice suffer from seizures, a phenotype consistent with excessive hippocampal network activity. Loss of syndapin I causes defects in presynaptic membrane trafficking processes, which are especially evident under high-capacity retrieval conditions, accumulation of endocytic intermediates, loss of synaptic vesicle (SV) size control, impaired activity-dependent SV retrieval and defective synaptic activity. Detailed molecular analyses demonstrate that syndapin I plays an important role in the recruitment of all dynamin isoforms, central players in vesicle fission reactions, to the membrane. Consistently, syndapin I KO mice share phenotypes with dynamin I KO mice, whereas their seizure phenotype is very reminiscent of fitful mice expressing a mutant dynamin. Thus, syndapin I acts as pivotal membrane anchoring factor for dynamins during regeneration of SVs.

Revealing the dynamics of ultrarelativistic non-equilibrium many-electron systems with phase space tomography.

The description of physical processes with many-particle systems is a key approach to the modeling of numerous physical systems. For example in storage rings, where ultrarelativistic particles are agglomerated in dense bunches, the modeling and measurement of their phase-space distribution is of paramount importance: at any time the phase-space distribution not only determines the complete space-time evolution but also provides fundamental performance characteristics for storage ring operation. Here, we demonstrate a non-destructive tomographic imaging technique for the 2D longitudinal phase-space distribution of ultrarelativistic electron bunches. For this purpose, we utilize a unique setup, which streams turn-by-turn near-field measurements of bunch profiles at MHz repetition rates. To demonstrate the feasibility of our method, we induce a non-equilibrium state and show that the phase-space distribution microstructuring as well as the phase-space distribution dynamics can be observed in great detail. Our approach offers a pathway to control ultrashort bunches and supports, as one example, the development of compact accelerators with low energy footprints.

Using systemic serum amyloid A as a biomarker for synovial structure infections in horses with acute limb wounds.

BACKGROUND: In postoperative monitoring of synovial structure infection due to limb wounds, early recognition of a recurrence of synovial infection is indispensable to prevent further damage to the affected synovial structure. This study evaluated the role of serum amyloid A (SAA) as a systemic biomarker in disease monitoring and correlated this tool with clinical variables. METHODS: In this prospective cohort study, 55 horses with acute limb wounds were divided into two groups: those with (group 1, n = 26) or without (group 2, n = 29) a diagnosis of synovial structure penetration. SAA, lameness and body temperature were evaluated repeatedly and compared between groups. Correlations were explored between SAA and body temperature as well as lameness. The long-term outcome was also analysed. RESULTS: In both groups, SAA levels followed the characteristic rise-and-fall pattern observed in previous studies, with a significant increase up to a peak concentration within 48 hours, followed by a constant decline. Lameness and body temperature did not change significantly. SAA was not found to correlate with clinical variables at all time points. Three horses in group 1 had a recurrence of synovial sepsis with an associated increase in SAA. The long-term outcome was good. A total of 71% of the study population returned to pre-injury performance levels. CONCLUSION: Repeated measurements of SAA accurately reflected the course of synovial inflammation and thus provided a reliable and rapidly available tool to monitor the disease course and to adapt the treatment regimen. SAA should be routinely added to the postoperative management of such cases.

Asynchronous sampling for ultrafast experiments with low momentum compaction at the ANKA ring.

A high-repetition-rate pump-probe experiment is presented, based on the asynchronous sampling approach. The low-α mode at the synchrotron ANKA can be used for a time resolution down to the picosecond limit for the time-domain sampling of the coherent THz emission as well as for hard X-ray pump-probe experiments, which probe structural dynamics in the condensed phase. It is shown that a synchronization of better than 1 ps is achieved, and examples of phonon dynamics of semiconductors are presented.

Olive Oil Extracts and Oleic Acid Attenuate the LPS-Induced Inflammatory Response in Murine RAW264.7 Macrophages but Induce the Release of Prostaglandin E2.

Olive oil contains high amounts of oleic acid (OA). Although OA has been described to inhibit inflammatory processes, the effects of olive oil on cellular mechanisms remain poorly understood. Therefore, we compared the effects of major fatty acids (FA) from olive oil with those of olive oil extracts (OOE) on inflammatory mediators and alterations in the cellular phospholipid composition in murine macrophages. Upon treatment with different OOE, FA compositions of lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophages were analyzed using gas chromatography. Olive oil extracts and OA significantly reduced the LPS-induced expression of inducible nitric oxide synthase (iNos), cyclooxygenase (Cox2), and interleukin-6 mRNA. In addition, a significant decrease in Cox2 and iNos protein expression was observed. The formation of nitric oxide was significantly reduced, while the formation of prostaglandin (PG) E2 from arachidonic acid significantly increased after treatment with OOE or OA. The latter was associated with a shift in the phospholipid FA composition from arachidonic acid to OA, resulting in an elevated availability of arachidonic acid. Together, OOE and OA mediate anti-inflammatory effects in vitro but increase the release of arachidonic acid and hereinafter PGE2, likely due to elongation of OA and competitive incorporation of fatty acids into membrane phospholipids.

Cannabinoid receptor CB1 mediates baseline and activity-induced survival of new neurons in adult hippocampal neurogenesis.

BACKGROUND: Adult neurogenesis is a particular example of brain plasticity that is partially modulated by the endocannabinoid system. Whereas the impact of synthetic cannabinoids on the neuronal progenitor cells has been described, there has been lack of information about the action of plant-derived extracts on neurogenesis. Therefore we here focused on the effects of Delta9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) fed to female C57Bl/6 and Nestin-GFP-reporter mice on proliferation and maturation of neuronal progenitor cells and spatial learning performance. In addition we used cannabinoid receptor 1 (CB1) deficient mice and treatment with CB1 antagonist AM251 in Nestin-GFP-reporter mice to investigate the role of the CB1 receptor in adult neurogenesis in detail. RESULTS: THC and CBD differed in their effects on spatial learning and adult neurogenesis. CBD did not impair learning but increased adult neurogenesis, whereas THC reduced learning without affecting adult neurogenesis. We found the neurogenic effect of CBD to be dependent on the CB1 receptor, which is expressed over the whole dentate gyrus. Similarly, the neurogenic effect of environmental enrichment and voluntary wheel running depends on the presence of the CB1 receptor. We found that in the absence of CB1 receptors, cell proliferation was increased and neuronal differentiation reduced, which could be related to CB1 receptor mediated signaling in Doublecortin (DCX)-expressing intermediate progenitor cells. CONCLUSION: CB1 affected the stages of adult neurogenesis that involve intermediate highly proliferative progenitor cells and the survival and maturation of new neurons. The pro-neurogenic effects of CBD might explain some of the positive therapeutic features of CBD-based compounds.

Nutrient Composition of Different Hazelnut Cultivars Grown in Germany.

Hazelnuts are rarely cultivated in Germany, although they are a valuable source for macro- and micronutrients and can thus contribute to a healthy diet. Near the present, 15 varieties were cultivated in Thuringia, Germany, as a pilot study for further research. The aim of our study was to evaluate the micro- and macronutrient composition of representative, randomly mixed samples of the 15 different hazelnut cultivars. Protein, fat, and fiber contents were determined using established methods. Fatty acids, tocopherols, minerals, trace elements, and ultra-trace elements were analyzed using gas chromatography, high-performance liquid chromatography, and inductively coupled plasma triple quadrupole mass-spectrometry, respectively. We found that the different hazelnut varieties contained valuable amounts of fat, protein, dietary fiber, minerals, trace elements, and α-tocopherol, however, in different quantities. The variations in nutrient composition were independent of growth conditions, which were identical for all hazelnut varieties. Therefore, each hazelnut cultivar has its specific nutrient profile.

Click Chemistry (CuAAC) and Detection of Tagged de novo Synthesized Proteins in Drosophila.

Copper-catalyzed azide-alkyne-cycloaddition (CuAAC), also known as 'click chemistry' serves as a technique for bio-orthogonal, that is, bio-compatible labeling of macromolecules including proteins or lipids. Click chemistry has been widely used to covalently, selectively, and efficiently attach probes such as fluorophores or biotin to small bio-orthogonal chemical reporter groups introduced into macromolecules. In bio-orthogonal non-canonical amino acid tagging (BONCAT) and fluorescent non-canonical amino acid tagging (FUNCAT) proteins are metabolically labeled with a non-canonical, azide-bearing amino acid and subsequently CuAAC-clicked either to an alkyne-bearing biotin (BONCAT) for protein purification, Western blot, or mass spectrometry analyses or to an alkyne-bearing fluorophore (FUNCAT) for immunohistochemistry. In combination with mass spectrometry, these kinds of labeling and tagging strategies are a suitable option to identify and characterize specific proteomes in living organisms without the need of prior cell sorting. Here, we provide detailed protocols for FUNCAT and BONCAT click chemistry and the detection of tagged de novo synthesized proteins in Drosophila melanogaster.

In Vitro Digested Nut Oils Attenuate the Lipopolysaccharide-Induced Inflammatory Response in Macrophages.

Nut consumption is known for its health benefits, in particular in inflammatory diseases. A possible mechanism for these effects could be their beneficial fatty acid composition. Nuts mainly contain mono- and polyunsaturated fatty acids, which have anti-inflammatory properties. However, studies investigating the effects of nut extracts on inflammatory processes on the molecular level are rare. We therefore prepared oily nut extracts after in vitro digestion and saponification of the fat-soluble constituents. Besides chromatographic analysis, cell culture experiments were performed using murine macrophages (RAW264.7) to study the capacity of different nut extracts (hazelnut, almond, walnut, macadamia, and pistachio) to modulate inflammatory processes. Oleic acid was the main fatty acid in hazelnut, almond, macadamia, and pistachio extracts. Both oily nut extracts and pure oleic acid significantly reduced the LPS-induced expression of iNos, Cox2, Tnfα, Il1ß, and Il6 mRNAs. iNos protein expression was down-regulated followed by reduced nitric oxide formation. Thus, nut extracts at concentrations achievable in the digestive tract inhibit the expression and formation of inflammatory mediators in macrophages. Hence, a beneficial contribution of nut consumption to inflammatory diseases can be assumed. We are convinced that these results provide new insights on the molecular mechanisms involved in the health-beneficial effects of nuts.

From self-organization in relativistic electron bunches to coherent synchrotron light: observation using a photonic time-stretch digitizer.

In recent and future synchrotron radiation facilities, relativistic electron bunches with increasingly high charge density are needed for producing brilliant light at various wavelengths, from X-rays to terahertz. In such conditions, interaction of electron bunches with their own emitted electromagnetic fields leads to instabilities and spontaneous formation of complex spatial structures. Understanding these instabilities is therefore key in most electron accelerators. However, investigations suffer from the lack of non-destructive recording tools for electron bunch shapes. In storage rings, most studies thus focus on the resulting emitted radiation. Here, we present measurements of the electric field in the immediate vicinity of the electron bunch in a storage ring, over many turns. For recording the ultrafast electric field, we designed a photonic time-stretch analog-to-digital converter with terasamples/second acquisition rate. We could thus observe the predicted link between spontaneous pattern formation and giant bursts of coherent synchrotron radiation in a storage ring.

Large herbivores in novel ecosystems - Habitat selection by red deer (Cervus elaphus) in a former brown-coal mining area.

After centuries of range contraction, many megafauna species are recolonizing parts of Europe. One example is the red deer (Cervus elaphus), which was able to expand its range and is now found in half the areas it inhabited in the beginning of the 19th century. Herbivores are important ecosystem engineers, influencing e.g. vegetation. Knowledge on their habitat selection and their influence on ecosystems might be crucial for future landscape management, especially for hybrid and novel ecosystems emerging in post-industrial landscapes. In this study, red deer habitat selection was studied in a former brown-coal mining area in Denmark. Here, natural settings were severely changed during the mining activity and its current landscape is in large parts managed by hunters as suitable deer habitat. We assessed red deer habitat preferences through feces presence and camera traps combined with land cover data from vegetation sampling, remote sensing and official geographic data. Red deer occurrence was negatively associated with human disturbance and positively associated with forage availability, tree cover and mean terrain height. Apparently, red deer are capable of recolonizing former industrial landscapes quite well if key conditions such as forage abundance and cover are appropriate. In the absence of carnivores, human disturbance, such as a hunting regime is a main reason why deer avoid certain areas. The resulting spatial heterogeneity red deer showed in their habitat use of the study area might be a tool to preserve mosaic landscapes of forest and open habitats and thus promote biodiversity in abandoned post-industrial landscapes.

Cell Type-specific Metabolic Labeling of Proteins with Azidonorleucine in Drosophila.

Advanced mass spectrometry technology has pushed proteomic analyses to the forefront of biological and biomedical research. Limitations of proteomic approaches now often remain with sample preparations rather than with the sensitivity of protein detection. However, deciphering proteomes and their context-dependent dynamics in subgroups of tissue-embedded cells still poses a challenge, which we meet with a detailed version of our recently established protocol for cell-selective and temporally controllable metabolic labeling of proteins in Drosophila. This method is based on targeted expression of a mutated variant of methionyl-tRNA-synthetase, MetRSL262G, which allows for charging methionine tRNAs with the non-canonical amino acid azidonorleucine (ANL) and, thus, for detectable ANL incorporation into nascent polypeptide chains.

Monitoring Astrocytic Proteome Dynamics by Cell Type-Specific Protein Labeling.

The ability of the nervous system to undergo long-term plasticity is based on changes in cellular and synaptic proteomes. While many studies have explored dynamic alterations in neuronal proteomes during plasticity, there has been less attention paid to the astrocytic counterpart. Indeed, progress in identifying cell type-specific proteomes is limited owing to technical difficulties. Here, we present a cell type-specific metabolic tagging technique for a mammalian coculture model based on the bioorthogonal amino acid azidonorleucine and the mutated Mus musculus methionyl-tRNA synthetaseL274G enabling azidonorleucine introduction into de novo synthesized proteins. Azidonorleucine incorporation resulted in cell type-specific protein labeling and retained neuronal or astrocytic cell viability. Furthermore, we were able to label astrocytic de novo synthesized proteins and identified both Connexin-43 and 60S ribosomal protein L10a upregulated upon treatment with Brain-derived neurotrophic factor in astrocytes of a neuron-glia coculture. Taken together, we demonstrate the successful dissociation of astrocytic from neuronal proteomes by cell type-specific metabolic labeling offering new possibilities for the analyses of cell type-specific proteome dynamics.

Cell-selective labelling of proteomes in Drosophila melanogaster.

The specification and adaptability of cells rely on changes in protein composition. Nonetheless, uncovering proteome dynamics with cell-type-specific resolution remains challenging. Here we introduce a strategy for cell-specific analysis of newly synthesized proteomes by combining targeted expression of a mutated methionyl-tRNA synthetase (MetRS) with bioorthogonal or fluorescent non-canonical amino-acid-tagging techniques (BONCAT or FUNCAT). Substituting leucine by glycine within the MetRS-binding pocket (MetRS(LtoG)) enables incorporation of the non-canonical amino acid azidonorleucine (ANL) instead of methionine during translation. Newly synthesized proteins can thus be labelled by coupling the azide group of ANL to alkyne-bearing tags through 'click chemistry'. To test these methods for applicability in vivo, we expressed MetRS(LtoG) cell specifically in Drosophila. FUNCAT and BONCAT reveal ANL incorporation into proteins selectively in cells expressing the mutated enzyme. Cell-type-specific FUNCAT and BONCAT, thus, constitute eligible techniques to study protein synthesis-dependent processes in complex and behaving organisms.

Interleukin-10-treated dendritic cells modulate immune responses of naive and sensitized T cells in vivo.

Interleukin-10 is a pleiotropic cytokine known to have inhibitory effects on the accessory functions of dendritic cells. In vitro, interleukin-10 converts immature dendritic cells into tolerizing antigen- presenting cells. To assess whether interleukin-10-treated dendritic cells exert tolerizing effects in vivo, CD4+ T cells from DO11.10 ovalbumin-T cell receptor transgenic mice were transferred to syngeneic BALB/c recipients. Recipient animals were treated with ovalbumin-pulsed/unpulsed, interleukin-10-treated/untreated CD11c+ dendritic cells thereafter and ovalbumin-specific proliferation of lymph node cells was assessed by restimulation with the peptide in vitro. In prophylactic experiments, recipients received naive CD4+ DO11.10 T cells and were immunized with ovalbumin323-339 peptide in incomplete Freund's adjuvant after treatment with various subtypes of dendritic cells. Strong ovalbumin-specific proliferation was observed in animals immunized with control ovalbumin-dendritic cells. Minimal proliferation was found in mice treated with ovalbumin-pulsed, interleukin-10-treated dendritic cells. In therapeutic experiments, preactivated CD4+ DO11.10 T cells were transferred, and recipients were treated with dendritic cells as described. Ovalbumin-specific proliferation was strong in recipients treated with ovalbumin-dendritic cells. CD4+ T cell proliferation from ovalbumin-interleukin-10-dendritic cell treated animals was below background. When delayed type hypersensitivity reactions in the footpads of prophylactically or therapeutically vaccinated animals were tested, mice treated with ovalbumin-interleukin-10-dendritic cells showed no footpad swelling compared with controls. Rechallenge with the antigen in vitro and in vivo did not alter the inhibitory effect of interleukin-10-treated dendritic cells. Thus, interleukin-10-treated dendritic cells inhibit ovalbumin-specific immune responses in naive and sensitized mice.