Interferon-producing cells develop from murine CD31(high)/Ly6C(-) marrow progenitors

In this study, we sorted total bone marrow (BM) into six distinct subsets based on surface expression of CD31 and Ly6C and investigated the capacity of these subsets to acquire characteristics of plasmacytoid dendritic cells (PDCs) after in vitro culture with FMS-like tyrosine kinase 3 ligand (Flt3-L). Cultured CD31(high)/Ly6C(-) cells were the only subset that consistently developed immunophenotypic, functional, and morphologic characteristics of PDCs. Culture of this subset resulted in expression of CD11c, B220, and the PDC-specific marker 440C and secretion of interferon-alpha (IFN-alpha) when stimulated with CPG ODN 2216. Cultured cells displayed the typical plasmacytoid morphology of PDCs with eccentrically located nucleus and mature lymphoid chromatin. Unlike conventional dendritic cells (CDCs) that can be generated from CD31(high)/Ly6C(-), CD31(+)/Ly6C(+), and CD31(-)/Ly6C(high) BM subpopulations, PDCs can only be derived from the CD31(high)/Ly6C(-) subset, the subset that reportedly contains the highest frequency of early and late cobblestone area forming cells (CAFC).     

Blood System Formation in the Urochordate Ciona intestinalis Requires the Variable Receptor vCRL1

Adaptive immune systems are present only in vertebrates. How do all the remaining animals withstand continuous attacks of permanently evolving pathogens? Even in the absence of adaptive immunity, every organism must be able to unambiguously distinguish "self" cells from any imaginable "nonself." Here, we analyzed the function of highly polymorphic gene vCRL1, which is expressed in follicle and blood cells of Ciona intestinalis, pointing to possible recognition roles either during fertilization or in immune reactions. By using segregation analysis, we demonstrate that vCRL1 locus is not involved in the control of self-sterility. Interestingly, genetic knockdown of vCRL1 in all tissues or specifically in hemocytes results in a drastic developmental arrest during metamorphosis exactly when blood system formation in Ciona normally occurs. Our data demonstrate that vCRL1 gene might be essential for the establishment of a functional blood system in Ciona. Presumably, presence of the vCRL1 receptor on the surface of blood cells renders them as self, whereas any cell lacking it is referred to as nonself and will be consequently destroyed. We propose that individual-specific receptor vCRL1 might be utilized to facilitate somatic self/nonself discrimination.     

Transcutaneous measurement of renal function in conscious mice

Determination of glomerular filtration rate (GFR) in conscious mice is cumbersome for the experimenter and stressful for the animals. Here we report on a simple new technique allowing the transcutaneous measurement of GFR in conscious mice. This approach extends our previously developed technique for rats to mice. The technique relies on a miniaturized device equipped with an internal memory that permits the transcutaneous measurement of the elimination kinetics of the fluorescent renal marker FITC-sinistrin. This device is described and validated compared with FITC-sinistrin plasma clearance in healthy, unilaterally nephrectomized and pcy mice. In summary, we describe a technique allowing the measurement of renal function in freely moving mice independent of blood or urine sampling as well as of laboratory assays.     

Isolation of cyanophycin from tobacco and potato plants with constitutive plastidic cphATe gene expression

A chimeric cyanophycin synthetase gene composed of the cphATe coding region from the cyanobacterium Thermosynechococcus elongatus BP-1, the constitutive 35S promoter and the plastid targeting sequence of the integral photosystem II protein PsbY was transferred to the tobacco variety Petit Havanna SRI and the commercial potato starch production variety Albatros. The resulting constitutive expression of cyanophycin synthetase leads to polymer contents in potato leaf chloroplasts of up to 35 mg/g dry weight and in tuber amyloplasts of up to 9 mg/g dry weight. Both transgenic tobacco and potato were used for the development of isolation methods applicable for large-scale extraction of the polymer. Two different procedures were developed which yielded polymer samples of 80 and 90% purity, respectively.     

Surface modification of an acoustic biosensor allowing the detection of low concentrations of cancer markers

Analyte detection with biosensors is strongly influenced by the preparation of the biosensor surface including choice of sensing layers and coupling methods for corresponding capture molecules. We investigated the influence of different coupling procedures, especially considering coupling chemistry and incubation times for reagents, by means of surface acoustic wave (SAW) biosensors. The effect on the signal response was tested in two subsequent protein assays. Our optimized coupling procedure allowed the detection of the breast cancer markers HER-2 (human epidermal growth factor receptor-2) and TIMP-1 (tissue inhibitor of metalloproteinase-1) below the respective clinical cutoff values of only a few nanograms per milliliter.     

Peripheral and central inputs shape network dynamics in the developing visual cortex in vivo

Spontaneous network activity constitutes a central theme during the development of neuronal circuitry [1, 2]. Before the onset of vision, retinal neurons generate waves of spontaneous activity that are relayed along the ascending visual pathway [3, 4] and shape activity patterns in these regions [5, 6]. The spatiotemporal nature of retinal waves is required to establish precise functional maps in higher visual areas, and their disruption results in enlarged axonal projection areas (e.g., [7-10]). However, how retinal inputs shape network dynamics in the visual cortex on the cellular level is unknown. Using in vivo two-photon calcium imaging, we identified two independently occurring patterns of network activity in the mouse primary visual cortex (V1) before and at the onset of vision. Acute manipulations of spontaneous retinal activity revealed that one type of network activity largely originated in the retina and was characterized by low synchronicity (L-) events. In addition, we identified a type of high synchronicity (H-) events that required gap junction signaling but were independent of retinal input. Moreover, the patterns differed in wave progression and developmental profile. Our data suggest that different activity patterns have complementary functions during the formation of synaptic circuits in the developing visual cortex.     

Spatial scales of bacterial diversity in cold-water coral reef ecosystems

Background

Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning.

Methodology/Principal Findings

Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA), was investigated with respect to (i) microbial habitat type and (ii) coral species and color, as well as the three spatial components (iii) geomorphologic reef zoning, (iv) reef boundary, and (v) reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus) and ambient microbial habitats (seawater, sediments). This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity.

Conclusions/Significance

This study presents the first multi-scale survey of bacterial diversity in cold-water coral reefs, spanning a total of five observational levels including three spatial scales. It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has fundamental implications for the monitoring of microbial diversity and function in those ecosystems.     

Pipecolic Acid,an Endogenous Mediator of Defense Amplification and Priming,Is a Critical Regulator of Inducible Plant Immunity

Metabolic signals orchestrate plant defenses against microbial pathogen invasion. Here, we report the identification of the non-protein amino acid pipecolic acid (Pip), a common Lys catabolite in plants and animals, as a critical regulator of inducible plant immunity. Following pathogen recognition, Pip accumulates in inoculated Arabidopsis thaliana leaves, in leaves distal from the site of inoculation, and, most specifically, in petiole exudates from inoculated leaves. Defects of mutants in AGD2-LIKE DEFENSE RESPONSE PROTEIN1 (ALD1) in systemic acquired resistance (SAR) and in basal, specific, and β-aminobutyric acid–induced resistance to bacterial infection are associated with a lack of Pip production. Exogenous Pip complements these resistance defects and increases pathogen resistance of wild-type plants. We conclude that Pip accumulation is critical for SAR and local resistance to bacterial pathogens. Our data indicate that biologically induced SAR conditions plants to more effectively synthesize the phytoalexin camalexin, Pip, and salicylic acid and primes plants for early defense gene expression. Biological priming is absent in the pipecolate-deficient ald1 mutants. Exogenous pipecolate induces SAR-related defense priming and partly restores priming responses in ald1. We conclude that Pip orchestrates defense amplification, positive regulation of salicylic acid biosynthesis, and priming to guarantee effective local resistance induction and the establishment of SAR.     

Recently emerged swine influenza A virus (H2N3) causes severe pneumonia in Cynomolgus macaques

The triple reassortant H2N3 virus isolated from diseased pigs in the United States in 2006 is pathogenic for certain mammals without prior adaptation and transmits among swine and ferrets. Adaptation, in the H2 hemagglutinin derived from an avian virus, includes the ability to bind to the mammalian receptor, a significant prerequisite for infection of mammals, in particular humans, which poses a big concern for public health. Here we investigated the pathogenic potential of swine H2N3 in Cynomolgus macaques, a surrogate model for human influenza infection. In contrast to human H2N2 virus, which served as a control and largely caused mild pneumonia similar to seasonal influenza A viruses, the swine H2N3 virus was more pathogenic causing severe pneumonia in nonhuman primates. Both viruses replicated in the entire respiratory tract, but only swine H2N3 could be isolated from lung tissue on day 6 post infection. All animals cleared the infection whereas swine H2N3 infected macaques still presented with pathologic changes indicative of chronic pneumonia at day 14 post infection. Swine H2N3 virus was also detected to significantly higher titers in nasal and oral swabs indicating the potential for animal-to-animal transmission. Plasma levels of IL-6, IL-8, MCP-1 and IFNγ were significantly increased in swine H2N3 compared to human H2N2 infected animals supporting the previously published notion of increased IL-6 levels being a potential marker for severe influenza infections. In conclusion, the swine H2N3 virus represents a threat to humans with the potential for causing a larger outbreak in a non-immune or partially immune population. Furthermore, surveillance efforts in farmed pig populations need to become an integral part of any epidemic and pandemic influenza preparedness.