Comparison of calving and revenue-generating qualities in beef-sired male and female progeny from dairy cows

Although interest in beef-on-dairy breeding strategies is intensifying, little is actually known of the performance differences between beef-sired male and female progeny of dairy cows. The objective was therefore to use a large cross-sectional database of up to 1,389,670 animals to investigate if performance differences existed between male and female progeny generated from beef-on-dairy matings; the focus was on characteristics of interest to both the dairy producer (i.e., gestation length, calving performance, perinatal mortality, and calf sale value) and the beef producer (i.e., slaughter-related traits). While statistical differences existed between both sexes, the observed differences were not always biologically large, with some favoring females (e.g., calving traits and age at slaughter) and some favoring males (i.e., carcass weight). Beef-sired male calves had, on average, a 0.8 d longer gestation than their female counterparts; the sex difference in dairy-sired calves was, on average, 1.1 d, with the advantage to females. The odds of a difficult calving was 2.2 times greater for beef-sired male calves relative to beef-sired female calves; this translated to a difference in predicted probability of dystocia between the sexes of 1.8 percentage units. Male beef-sired calves sold at auctions <42 d of age were worth, on average, €32.40 more than beef-sired female calves. Focusing just on beef-sired progeny, relative to heifer carcasses (mean weight of 280.0 kg), the carcasses of steers (mean weight of 336.9 kg) and bulls (mean weight of 335.4) were 55.4 to 56.9 kg heavier. Based on a 15-point conformation scale, the carcasses of bulls were 1 unit superior to heifers, with the carcasses of the latter being 0.06 units better than steers. Heifers were slaughtered, on average, 79.1 d younger than steers although heifers were slaughtered, on average, 93.8 d older than bulls, the latter generally being finished on a more intensive diet relative to steers and heifers in Ireland. In conclusion, many benefits exist for beef-sired heifer calves in that they had, on average, shorter gestations with less expected assistance required at calving and, although their calf value was less and their carcasses were lighter than their male counterparts, they were slaughtered several months younger than steers.

Mean breed performance of the progeny from beef-on-dairy matings

Gains through breeding can be achieved through a combination of both between-breed and within-breed selection. Two suites of traits of particular interest to dairy producers when selecting beef bulls for mating to dairy females are calving-related attributes and the expected value of the subsequent calf, the latter usually being a function of expected carcass value. Estimated breed effects can be informative, particularly in the absence of across-breed genetic evaluations. The objective of the present study was to use a large national database of the progeny from beef-on-dairy matings to estimate the mean breed effects of the used beef sires. Calving performance (i.e., gestation length, calving difficulty score, and perinatal morality) as well as calf value were investigated; a series of slaughter-related traits (i.e., carcass metrics and age at slaughter) of the prime progeny were also investigated. Phenotypic data on up to 977,037 progeny for calving performance, 79,903 for calf price and 103,175 for carcass traits (including dairy × dairy progeny for comparative purposes) were used; sire breeds represented were Holstein-Friesian, Angus, Aubrac, Belgian Blue, Charolais, Hereford, Limousin, Salers, and Simmental. Large interbreed differences existed. The mean gestation length of male calves from beef sires varied from 282.3 d (Angus) to 287.4 d (Limousin) which were all longer than the mean of 280.9 d for Holstein-Friesian sired male calves. Relative to a Holstein-Friesian sire, the odds of dystocia varied from 1.43 (Angus) to 4.77 (Belgian Blue) but, once adjusted for both the estimated maternal genetic merit of the dam and direct genetic merit of the calf for calving difficulty, the range in odds ratios shrunk. A difference of €125.4 existed in calf sale price between the progeny of the different beef breeds investigated which represented over twice the residual standard deviation in calf price within the day of sale-Angus was the cheapest while Charolais calves were, on average, the most expensive calves. Mean carcass weight of steers, not adjusted for age at slaughter or carcass fat, varied from 327.1 kg (Angus) to 363.2 kg (Belgian Blue) for the beef breeds with the mean carcass weight of Holstein-Friesian steer progeny being 322.4 kg. Belgian Blues had, on average, the best carcass conformation with the Herefords and Angus having the worst of all beef breeds. Angus and Hereford steers were slaughtered the youngest of all beef breeds but just 9 d younger than the average of all other beef breeds yet 24 d younger than Holstein-Friesian sired progeny. Clear breed differences in calving and carcass performance exist among beef breeds mated to dairy females. Those breeds excelling in calving performance were not necessarily the best for carcass merit.

The Multifaceted Actions of CD73 During Development and Suppressive Actions of Regulatory T Cells

Adenosine (Ado) has been shown to have immunosuppressive effects in a variety of diseases. It can either be released directly into the extracellular environment by cells, or it can be produced by degradation of ATP within the extracellular spaces. This extracellular pathway is facilitated by the concerted actions of the ectoenzymes CD39 and CD73. In a first step CD39 dephosphorylates ATP to ADP and AMP, respectively, and in a second step CD73 converts AMP to Ado. Thus, activity of CD73 on the cell surface of cells is the rate limiting step in the generation of extracellular Ado. Among T cells, CD73 is most abundantly expressed by regulatory T cells (Tregs) and is even upregulated after their activation. Functionally, the generation of Ado by CD73+ Tregs has been shown to play a role in immune suppression of dendritic cells, monocytes and T cells, and the defined expression of CD73 by Tregs in immunosuppressive environments, such as tumors, made CD73 a novel checkpoint inhibitor. Therefore, therapeutical intervention by anti-CD73 antibodies or by chemical inhibitors of the enzymatic function is currently under investigation in some preclinical animal models. In the following we summarize the expression pattern and the possible functions of CD73 in T cells and Tregs, and exemplify novel ways to manipulate CD73 functions in Tregs to stimulate anti-tumor immunity.

Regulatory T Cells Prevent Neutrophilic Infiltration of Skin during Contact Hypersensitivity Reactions by Strengthening the Endothelial Barrier

The healing phase of contact hypersensitivity reactions is critically dependent on regulatory T cells (Tregs), but even the early inflammatory phase, that is, 6-24 hours after induction of a contact hypersensitivity reaction, is susceptible to Treg-mediated suppression. To investigate the underlying mechanisms, we injected Tregs before the challenge and analyzed the skin-infiltrating cells as early as 6 hours later. Early on, we found mainly neutrophils in the challenged skin, but only a few T cells. This influx of neutrophils was blocked by the injection of Tregs, indicating that they were able to prevent the first wave of leukocytes, which are responsible for starting an immune reaction. As an underlying mechanism, we identified that Tregs can tighten endothelial junctions by inducing intracellular cAMP, leading to protein kinase A-RhoA‒dependent signaling. This eventually reorganizes endothelial junction proteins, such as Notch3, Nectin 2, Filamin B, and VE-cadherin, all of which contribute to the tightening of the endothelial barrier. In summary, Tregs prevent the leakage of proinflammatory cells from and into the tissue, which establishes a mechanism to downregulate immune reactions.

ATP and Its Metabolite Adenosine as Regulators of Dendritic Cell Activity

Adenosine (Ado) is a well-studied neurotransmitter, but it also exerts profound immune regulatory functions. Ado can (i) actively be released by various cells into the tissue environment and can (ii) be produced through the degradation of extracellular ATP by the concerted action of CD39 and CD73. In this sequence of events, the ectoenzyme CD39 degrades ATP into ADP and AMP, respectively, and CD73 catalyzes the last step leading to the production of Ado. Extracellular ATP acts as a “danger” signal and stimulates immune responses, i.e. by inflammasome activation. Its degradation product Ado on the other hand acts rather anti-inflammatory, as it down regulates functions of dendritic cells (DCs) and dampens T cell activation and cytokine secretion. Thus, the balance of proinflammatory ATP and anti-inflammatory Ado that is regulated by CD39⁺/CD73⁺ immune cells, is important for decision making on whether tolerance or immunity ensues. DCs express both ectoenzymes, enabling them to produce Ado from extracellular ATP by activity of CD73 and CD39 and thus allow dampening of the proinflammatory activity of adjacent leukocytes in the tissue. On the other hand, as most DCs express at least one out of four so far known Ado receptors (AdoR), DC derived Ado can also act back onto the DCs in an autocrine manner. This leads to suppression of DC functions that are normally involved in stimulating immune responses. Moreover, ATP and Ado production thereof acts as “find me” signal that guides cellular interactions of leukocytes during immune responses. In this review we will state the means by which Ado producing DCs are able to suppress immune responses and how extracellular Ado conditions DCs for their tolerizing properties.

Production of Extracellular Adenosine by CD73+ Dendritic Cells Is Crucial for Induction of Tolerance in Contact Hypersensitivity Reactions

Dendritic cells (DCs) express the ecto-5'-nucleotidase CD73 that generates immunosuppressive adenosine (Ado) by dephosphorylation of extracellular Ado monophosphate and diphosphate. To investigate whether CD73-derived Ado has immune-suppressive activity, 2,4-dinitrothiocyanobenzene (DNTB) was applied to skin of wild-type (WT) or CD73-deficient (CD73^-/-) mice, followed by sensitization and challenge with 2,4-dinitrofluorobenzene. In this model, we show the induction of tolerance by DNTB against 2,4-dinitrofluorobenzene only in WT but not in CD73^-/- mice. Analysis of skin DCs showed increased expression of CD73 after application of DNTB in WT mice. That was accompanied by elevated concentrations of extracellular Ado in the lymph node. Moreover, T cells expressed markers for anergy, namely EGR2 and NDRG1 in DNTB-treated WT mice and they exhibited impaired proliferation upon ex vivo re-stimulation. Similarly, in vitro we observed that Ado-producing WT DCs, but not CD73^-/- DCs, rendered transgenic T cells from OTII mice (OTII T cells) hyporeactive, decreased their T-cell costimulatory signaling, and induced up-regulation of EGR2 and NDRG1. Thus, these data show that expression of CD73 by DCs, which triggers elevated levels of extracellular Ado, is a crucial mechanism for the induction of anergic T cells and tolerance.

ASD and schizophrenia show distinct developmental profiles in common genetic overlap with population-based social communication difficulties

Difficulties in social communication are part of the phenotypic overlap between autism spectrum disorders (ASD) and schizophrenia. Both conditions follow, however, distinct developmental patterns. Symptoms of ASD typically occur during early childhood, whereas most symptoms characteristic of schizophrenia do not appear before early adulthood. We investigated whether overlap in common genetic influences between these clinical conditions and impairments in social communication depends on the developmental stage of the assessed trait. Social communication difficulties were measured in typically-developing youth (Avon Longitudinal Study of Parents and Children, N⩽5553, longitudinal assessments at 8, 11, 14 and 17 years) using the Social Communication Disorder Checklist. Data on clinical ASD (PGC-ASD: 5305 cases, 5305 pseudo-controls; iPSYCH-ASD: 7783 cases, 11 359 controls) and schizophrenia (PGC-SCZ2: 34 241 cases, 45 604 controls, 1235 trios) were either obtained through the Psychiatric Genomics Consortium (PGC) or the Danish iPSYCH project. Overlap in genetic influences between ASD and social communication difficulties during development decreased with age, both in the PGC-ASD and the iPSYCH-ASD sample. Genetic overlap between schizophrenia and social communication difficulties, by contrast, persisted across age, as observed within two independent PGC-SCZ2 subsamples, and showed an increase in magnitude for traits assessed during later adolescence. ASD- and schizophrenia-related polygenic effects were unrelated to each other and changes in trait-disorder links reflect the heterogeneity of genetic factors influencing social communication difficulties during childhood versus later adolescence. Thus, both clinical ASD and schizophrenia share some genetic influences with impairments in social communication, but reveal distinct developmental profiles in their genetic links, consistent with the onset of clinical symptoms.

Expression of CD73 slows down migration of skin dendritic cells, affecting the sensitization phase of contact hypersensitivity reactions in mice

BACKGROUND

Application of haptens to the skin induces release of immune stimulatory ATP into the extracellular space. This "danger" signal can be converted to immunosuppressive adenosine (ADO) by the action of the ectonucleotidases CD39 and CD73, expressed by skin and immune cells. Thus, the expression and regulation of CD73 by skin derived cells may have crucial influence on the outcome of contact hypersensitivity (CHS) reactions.

OBJECTIVE

To investigate the role of CD73 expression during 2,4,6-trinitrochlorobenzene (TNCB) induced CHS reactions.

METHODS

Wild type (wt) and CD73 deficient mice were subjected to TNCB induced CHS. In the different mouse strains the resulting ear swelling reaction was recorded along with a detailed phenotypic analysis of the skin migrating subsets of dendritic cells (DC).

RESULTS

In CD73 deficient animals the motility of DC was higher as compared to wt animals and in particular after sensitization we found increased migration of Langerin⁺ DC from skin to draining lymph nodes (LN). In the TNCB model this led to a stronger sensitization as indicated by increased frequency of interferon-γ producing T cells in the LN and an increased ear thickness after challenge.

CONCLUSION

CD73 derived ADO production slows down migration of Langerin⁺ DC from skin to LN. This may be a crucial mechanism to avoid over boarding immune reactions against haptens.

Down-Regulation of CD62L Shedding in T Cells by CD39+ Regulatory T Cells Leads to Defective Sensitization in Contact Hypersensitivity Reactions

Injection of regulatory T cells (Tregs) followed by sensitization with 2,4,6-trinitrochlorobenzene induced a transient increase in size and cellularity of skin-draining lymph nodes (LNs) in mice. This led us to hypothesize that Tregs may affect the trafficking of T cells from and to peripheral LNs. Two to three hours after sensitization, we found fewer CD8⁺ T cells expressing CD62L in LNs compared with untreated controls. Injection of wild-type Tregs prevented this down-regulation of CD62L. In contrast, Tregs devoid of the adenosine triphosphate (ATP)-degrading ecto-enzyme CD39 were unable to do so. As for the mechanism of CD62L regulation, we found that ATP, which is released in skin upon hapten-exposure, is inducing the protease ADAM17 in LN-residing T cells via engagement of P₂X₇ ATP receptors. ADAM17 cleaves CD62L from the surface of CD8⁺ T cells, which in turn provide a signal for T cells to leave the LNs. This regulation of CD62L is disturbed by the presence of Tregs, because Tregs remove extracellular ATP from the tissue by activity of CD39 and, therefore, abrogate the shedding of CD62L. Thus, these data indicate that the regulation of ATP turnover by Tregs in skin and LNs is an important modulator for immune responses.

Immune Response After Radiofrequency Ablation and Surgical Resection in Nonsmall Cell Lung Cancer

The objective includes radiofrequency ablation (RFA) of a cancerous nodule results in immunogenic cell death. Tumor antigens are presented and the inflammatory environment may help stimulate adaptive and innate antitumor immunity. The objective of this study was to investigate the immune response following RFA and subsequent surgical resection in early stage non-small cell lung cancer (NSCLC). In methods, a single-session approach of computed tomography-guided tumor biopsy with immediate frozen section (and proof of NSCLC) was performed followed by RFA of the tumor in 4 patients with a solitary pulmonary nodule. Blood samples were collected before RFA and 3 days thereafter. All patients underwent radical surgical resection by video-assisted thoracoscopic lobectomy 8 days following RFA. In results, intense infiltrations of CD4⁺ and CD8⁺ lymphocytes were found along the perimeter of the RFA-treated tumor tissue, whereas the central tumor areas remained devoid of lymphocytes. In the peripheral blood, the frequency of proinflammatory, immunostimulatory IFNγ-secreting, and immunostimulatory BDCA-3⁺/B7-H3^- dendritic cells increased after RFA. Furthermore, a significant increase in T-cell proliferation was detected in T-cell assays after RFA and tumor resection. In this article, a local and systemic immune response subsequent to RFA and complete surgical resection in patients with NSCLC was identified for the first time. Treatment of patients with NSCLC with RFA and surgery leads to an activated and highly T-cell-stimulatory phenotype of dendritic cells, which may promote long-term immunity against NSCLC. The data suggest that the RFA-induced necrotic tumor debris can serve as an in situ antigen source to induce an autologous antitumor immune response.

Antibody Targeting of "Steady-State" Dendritic Cells Induces Tolerance Mediated by Regulatory T Cells

Dendritic cells (DCs) are often defined as pivotal inducers of immunity, but these proinflammatory properties only develop after stimulation or ex vivo manipulation of DCs. Under non-inflammatory conditions in vivo, DCs are embedded into a tissue environment and encounter a plethora of self-antigens derived from apoptotic material. This material is transported to secondary lymphoid organs. As DCs maintain their non-activated phenotype in a sterile tissue environment, interaction with T cells will induce rather regulatory T cells than effector T cells. Thus, DCs are not only inducers of immunity but are also critical for maintenance of peripheral tolerance. Therapeutically, intervention for the induction of long-lasting tolerance in several autoimmune conditions may therefore be possible by manipulating DC activation and/or targeting of DCs in their “natural” tissue environment.

Lack of replication for the myosin-18B association with mathematical ability in independent cohorts

Twin studies indicate that dyscalculia (or mathematical disability) is caused partly by a genetic component, which is yet to be understood at the molecular level. Recently, a coding variant (rs133885) in the myosin-18B gene was shown to be associated with mathematical abilities with a specific effect among children with dyslexia. This association represents one of the most significant genetic associations reported to date for mathematical abilities and the only one reaching genome-wide statistical significance. We conducted a replication study in different cohorts to assess the effect of rs133885 maths-related measures. The study was conducted primarily using the Avon Longitudinal Study of Parents and Children (ALSPAC), (N = 3819). We tested additional cohorts including the York Cohort, the Specific Language Impairment Consortium (SLIC) cohort and the Raine Cohort, and stratified them for a definition of dyslexia whenever possible. We did not observe any associations between rs133885 in myosin-18B and mathematical abilities among individuals with dyslexia or in the general population. Our results suggest that the myosin-18B variant is unlikely to be a main factor contributing to mathematical abilities.

Regulatory T cell-derived adenosine induces dendritic cell migration through the Epac-Rap1 pathway

Dendritic cells (DC) are one target for immune suppression by regulatory T cells (Treg), because their interaction results in reduced T cell stimulatory capacity and secretion of inhibitory cytokines in DC. We show that DC in the presence of Treg are more mobile as compared with cocultures with conventional CD4(+) T cells and form DC-Treg aggregates within 2 h of culture. The migration of DC was specifically directed toward Treg, as Treg, but not CD4(+) T cells, attracted DC in Boyden chambers. Treg deficient for the ectonucleotidase CD39 were unable to attract DC. Likewise, addition of antagonists for A2A adenosine receptors abolished the formation of DC-Treg clusters, indicating a role for adenosine in guiding DC-Treg interactions. Analysis of the signal transduction events in DC after contact to Treg revealed increased levels of cAMP, followed by activation of Epac1 and the GTPase Rap1. Subsequently activated Rap1 localized to the subcortical actin cytoskeleton in DC, providing a means by which directed locomotion of DC toward Treg is facilitated. In aggregate, these data show that Treg degrade ATP to adenosine via CD39, attracting DC by activating Epac1-Rap1-dependent pathways. As a consequence, DC-Treg clusters are formed and DC are rendered less stimulatory. This adenosine-mediated attraction of DC may therefore act as one mechanism by which Treg regulate the induction of immune responses by DC.

Efficient plasmonic scattering of colloidal silver particles through annealing-induced changes

We present an experimental study on the influence of annealing temperature on morphological changes of colloidal silver nanoparticles (Ag NPs) and their optical response. Monodisperse colloidal Ag NPs with diameter of 164 nm ± 15 nm have been fabricated by a facile two-step synthesis approach. The annealing effects on the Ag NPs have been investigated by means of optical measurements, scanning electron microscopy, x-ray photoelectron spectroscopy and x-ray diffraction. By annealing up to 440 °C morphology and chemical compositions of the Ag NPs changed. These changes affect the particle size and distribution, surface morphology, crystallinity and, most importantly, the oxidation state of the surface layer. The removal of an oxide layer leads to stronger light scattering from the nanoparticles and decreases parasitic light absorption at wavelengths above 400 nm. Strong light trapping has been observed for a silicon thin film with embedded annealed Ag NPs. This study demonstrates that colloidal Ag NPs for plasmonic solar cells need to be carefully processed and that they can potentially achieve high scatter efficiencies.

Childhood intelligence is heritable, highly polygenic and associated with FNBP1L

Intelligence in childhood, as measured by psychometric cognitive tests, is a strong predictor of many important life outcomes, including educational attainment, income, health and lifespan. Results from twin, family and adoption studies are consistent with general intelligence being highly heritable and genetically stable throughout the life course. No robustly associated genetic loci or variants for childhood intelligence have been reported. Here, we report the first genome-wide association study (GWAS) on childhood intelligence (age range 6-18 years) from 17,989 individuals in six discovery and three replication samples. Although no individual single-nucleotide polymorphisms (SNPs) were detected with genome-wide significance, we show that the aggregate effects of common SNPs explain 22-46% of phenotypic variation in childhood intelligence in the three largest cohorts (P=3.9 × 10(-15), 0.014 and 0.028). FNBP1L, previously reported to be the most significantly associated gene for adult intelligence, was also significantly associated with childhood intelligence (P=0.003). Polygenic prediction analyses resulted in a significant correlation between predictor and outcome in all replication cohorts. The proportion of childhood intelligence explained by the predictor reached 1.2% (P=6 × 10(-5)), 3.5% (P=10(-3)) and 0.5% (P=6 × 10(-5)) in three independent validation cohorts. Given the sample sizes, these genetic prediction results are consistent with expectations if the genetic architecture of childhood intelligence is like that of body mass index or height. Our study provides molecular support for the heritability and polygenic nature of childhood intelligence. Larger sample sizes will be required to detect individual variants with genome-wide significance.

Targeting of autoantigens to DEC205⁺ dendritic cells in vivo suppresses experimental allergic encephalomyelitis in mice

The dendritic and epithelial cell receptor with a m.w. of 205 kDa (DEC205) is expressed by dendritic cells (DCs) and facilitates Ag presentation. After injection of Ags coupled to Abs specific for DEC205 into mice, Ag presentation occurs by nonactivated DCs, which leads to induction of regulatory T cells (Tregs). To test this system for tolerance induction in experimental allergic encephalomyelitis (EAE), we created single-chain fragment variables (scFv) specific for DEC205 and fused the scFv to the self-Ag myelin oligodendrocyte glycoprotein (MOG; scFv DEC:MOG). An anti-β-galactosidase scFv:MOG fusion protein (scFv GL117:MOG) served as isotype control. After staining of DCs in vitro with purified scFv DEC:MOG, binding to DCs and colocalization with MHC class II was apparent, whereas isotype controls did not bind. We next injected scFv DEC:MOG into mice and observed elevated numbers of highly activated, IL-10-producing CD4⁺CD25⁺Foxp3⁺ Tregs (17% of CD4) in spleens, as compared with isotype controls and uninjected mice (12% of CD4). Furthermore, DCs isolated from scFv DEC:MOG-injected animals produced significantly increased levels of TGF-β. Most importantly, when EAE was induced in scFv DEC:MOG-injected mice, 90% of the mice were protected from EAE, whereas all mice in the isotype controls (scFv GL117:MOG) experienced development of EAE. When applying scFv DEC:MOG to mice that had already experienced EAE symptoms, abrogation of the disease in 90% of the animals was apparent, whereas all animals in the control groups experienced development of severe EAE. Thus, these data indicate that targeting of MOG to "steady-state" DCs in vivo may provide a tool to prevent and to treat EAE by a DC/Treg-driven mechanism.

Maternal cotyledons at birth predict blood pressure in childhood

INTRODUCTION

A small placental surface at birth has been shown to be associated with the development of hypertension in later life. In this study we extend this observation by looking at the relationship between the number of placental cotyledons and blood pressure in childhood. Because the number of cotyledons is correlated with the surface area, we hypothesized that fewer cotyledons would be associated with higher blood pressure.

METHODS

The Alspac study is a longitudinal study of 13,971 children born in Bristol. Their placentas were stored in formalin. We photographed the placentas of a sample of the children and related the number of maternal cotyledons to their blood pressure levels at age 9 years.

RESULTS

Contrary to our hypothesis, a greater number of maternal cotyledons was associated with higher blood pressure. Among boys, a greater number of cotyledons was associated with higher systolic and diastolic pressure but not with higher pulse pressure. Diastolic pressure rose by 2.2 mmHg (95% CI 0.6 to 3.7, p = 0.007) for every 10 additional cotyledons. Among girls, a greater number of cotyledons was associated with higher systolic pressure and pulse pressure but not with higher diastolic pressure. Pulse pressure rose by 2.7 mmHg (1.1-4.3, p < 0.001) for every 10 additional cotyledons. These associations were little changed by adjustment for placental surface area.

CONCLUSION

Our study has shown that a large number of maternal cotyledons is associated with raised blood pressure in childhood. The associations differ in the two sexes.

Mass and collision cross-section determination using a low-vacuum mass spectrometer

A simple low-vacuum mass spectrometer (LVMS) operating in the milliTorr pressure range was developed. The instrument resolves masses by time-of-flight measurements and employs a high-gain, fast-response detector that can operate at these pressures. This instrument allows simultaneous determination of mass and collision cross sections of the ions with the bath gas. Here we demonstrate the LVMS's abilities to determine total collision cross sections for the collisions of organic ions with three background gases, He, N(2), and SF(6). As a demonstration of the system capabilities, the unimolecular interconversion of photochemically produced C(7)H(7)(+) to the tropylium ion structure is investigated.

Immunization with MOG fused to a novel single chain fragment variable (scFv) for murine DEC-205 suppresses allergic experimental encephalomyelitis (EAE) in mice. (106.12)

The antigenreceptor DEC-205 is expressed by Dendritic cells (DC) and greatly increases antigen presentation. We have shown that in vivo loading of DC with antigen via anti-DEC-205:antigen conjugates induces immunosuppressive regulatory T-cells (Treg). Therefore we set out to create single chain fragment variables (scFv) specific for DEC-205 fused with the EAE antigen MOG, to target non-activated DC for induction of tolerance to EAE in vivo. A non-binding anti-b-gal scFv:MOG was created as control. ScFv:MOG fusions proteins were expressed and purified, and immunohistochemical staining of cytospins from isolated CD11c+ cells displayed a positive staining for DEC-scFv, colocalizing with MHC class II. For functional testing DEC-scFv:MOG was injected into mice. Lymph node DC were isolated thereafter and cocultivated with MOG-specific (2D2) T-cells. Strong T-cell proliferation was induced by DC from mice injected with DEC-scFv:MOG in contrast to controls. When analyzing the T-cell populations in DEC-scFv:MOG injected mice, we found enhanced numbers of CD4+CD25+FoxP3+ Treg (16% of CD4) as compared to control animals (10% of CD4). Most importantly, when EAE was induced in either DEC-scFv-MOG-injected or in control mice, none of the DEC-scFv:MOG injected mice developed EAE symptoms. In contrast, all animals in the control group developed a severe EAE. Thus, these data indicate that targeting of MOG to steady state DC in vivo prevents EAE by a Treg-driven mechanism.

Engagement of αIIbβ3 (GPIIb/IIIa) with ανβ3 integrin mediates interaction of melanoma cells with platelets: a connection to hematogenous metastasis

A mutual relationship exists between metastasizing tumor cells and components of the coagulation cascade. The exact mechanisms as to how platelets influence blood-borne metastasis, however, remain poorly understood. Here, we used murine B16 melanoma cells to observe functional aspects of how platelets contribute to the process of hematogenous metastasis. We found that platelets interfere with a distinct step of the metastasis cascade, as they promote adhesion of melanoma cells to the endothelium in vitro under shear conditions. Constitutively active platelet receptor GPIIb/IIIa (integrin αIIbβ3) expressed on Chinese hamster ovary cells promoted melanoma cell adhesion in the presence of fibrinogen, whereas blocking antibodies to aνβ3 integrin on melanoma cells or to GPIIb/IIIa significantly reduced melanoma cell adhesion to platelets. Furthermore, using intravital microscopy, we observed functional platelet-melanoma cell interactions, as platelet depletion resulted in significantly reduced melanoma cell adhesion to the injured vascular wall in vivo. Using a mouse model of hematogenous metastasis to the lung, we observed decreased metastasis of B16 melanoma cells to the lung by treatment with a mAb blocking the aν subunit of aνβ3 integrin. This effect was significantly reduced when platelets were depleted in vivo. Thus, the engagement of GPIIb/IIIa with aνβ3 integrin interaction mediates tumor cell-platelet interactions and highlights how this interaction is involved in hematogenous tumor metastasis.

ATP activates regulatory T Cells in vivo during contact hypersensitivity reactions

CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) require activation to develop their full suppressive capacity. Similar to conventional T cells, Tregs can be activated via their TCRs; however, other means may be in place. We injected naive and nonactivated Tregs, being CD69(-)CD44(low)CD62L(+) into mice, and analyzed their phenotype after sensitization or challenge with the contact sensitizer 2,4,6-trinitro-1-chlorobenzene. We found that Tregs acquired an activated phenotype (CD69(+)CD44(high)CD62L(-)) in the draining lymph node after sensitization. In contrast, Ag challenge activated Tregs in the blood. This tissue-specific activation was induced by ATP, which was released at the respective tissue sites after sensitization or challenge, respectively. To demonstrate that activation was also essential for the induction of the suppressive function of Tregs, Tregs were treated with ATP receptor antagonists. In this study, we show that ATP receptor antagonists abrogated the suppressive effects of injected naive Tregs in contact hypersensitivity reactions. Thus, these data indicate that activation of Tregs via ATP in vivo provides a novel pathway of stimulating the suppressive function of Tregs.

Gap junctions between regulatory T cells and dendritic cells prevent sensitization of CD8(+) T cells

BACKGROUND

Regulatory T (Treg) cells suppress the sensitization phase of experimental contact hypersensitivity (CHS) reactions when injected before hapten application.

OBJECTIVE

Our aim was to analyze the mechanisms by which Treg cells suppress the sensitization phase of CHS reactions.

METHODS

Treg cells were labeled with different fluorescent dyes and injected into naive mice directly before sensitization with the hapten 2,4,6-trinitro-1-chlorobenzene. Two days after sensitization, the lymphoid organs were analyzed for the presence of Treg cells and engagement of gap junctions with other cells. Dendritic cells (DCs) and effector CD8(+)T cells were isolated from the draining lymph nodes (LNs) of the differently treated groups, analyzed by using FACS for activation markers, and assessed for the T-cell stimulatory capacity of the DCs and the priming of effector T cells.

RESULTS

Only the LN-homing Treg cells suppressed the sensitization phase in CHS reactions by means of establishing gap junctions with DCs in the dLNs. This gap junctional intercellular communication led to downregulation of T-cell costimulatory molecules on the surface of the DCs, abrogating the priming, activation, and proliferation of hapten-specific CD8(+)T cells. Consequently, the ear-swelling response induced by challenge with the respective hapten was prevented.

CONCLUSION

Treg cells not only modulate ongoing CD4(+)T cell-mediated immune reactions at tissue sites but also abrogate the de novo induction of CD8(+)T cell-driven immune reactions by interfering with T-cell stimulatory activity of DCs through gap junctional intercellular communication.

ERK/p38 MAP-kinases and PI3K are involved in the differential regulation of B7-H1 expression in DC subsets

Regulatory molecules of the B7-H-family expressed by DC are important for immune homeostasis, but their regulation is largely unknown. When investigating the pathways regulating B7-H1 expression in monocyte-derived DC (MoDC), freshly isolated myeloid DC (mDC) and plasmacytoid DC, respectively, we showed that in MoDC and mDC B7-H1 expression was upregulated by a standard cytokine cocktail, poly I:C or LPS. MoDC utilize ERK and PI3K pathways to upregulate B7-H1 in response to cytokines, whereas p38 kinase was predominantly utilized in response to poly I:C. In mDC, ERK and p38 pathways are involved in B7-H1 regulation, and similar to MoDC, mainly p38 signaling was required for poly I:C-induced expression of B7-H1. Plasmacytoid DC responded only to CpG with upregulation of B7-H1 and in addition to p38 also utilized the PI3K and ERK pathways to regulate B7-H1 expression. As a functional consequence of B7-H1 expression on DC, we demonstrate downmodulation of IFN-gamma production in T cells. Thus, the differential regulation of B7-H1 on DC subsets may suppress immune responses variably, depending on the target DC population. Further analysis of the regulatory mechanisms may facilitate the development of new immunosuppressive therapies, utilizing the regulation of B7-H1 expression on DC.

Skin melanoma development in ret transgenic mice despite the depletion of CD25+Foxp3+ regulatory T cells in lymphoid organs

CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg) known to mediate self-tolerance were also shown to contribute to tumor progression. In mouse melanoma transplantation models, Treg depletion resulted in the stimulation of antitumor immune responses and tumor eradication. To study Treg in conditions close to the clinical situation, we used a ret transgenic mouse spontaneous melanoma model, which, in contrast to transplantation models, resembles human melanoma regarding clinical development. Significantly higher numbers of Treg were found in skin tumors and metastatic lymph nodes at early stages of melanoma progression compared with more advanced stages accompanied by the elevated CCR4 expression on Treg and higher production of its ligand CCL2 in tumor lesions. Numbers of tumor infiltrating Treg inversely correlated with Treg amounts in the bone marrow, suggesting their possible recruitment to melanoma lesions from this organ. The immunosuppressive function of Treg from transgenic tumor-bearing mice was similar to that from transgenic tumor-free mice or nontransgenic littermates. Although anti-CD25 mAb injections resulted in the efficient Treg depletion from lymphoid organs of transgenic mice, melanoma development was not significantly delayed. Furthermore, the treatment of mice with macroscopical tumors also failed to inhibit tumor progression, which correlated with the inability to deplete intratumoral Treg. We suggest that in the autochthonous melanoma genesis, other immunosuppressive cells could play an important role and replace immunosuppressive, tumor-promoting functions of Treg. Therefore, effective melanoma immunotherapy should include the inhibition of Treg migration into the tumor combined with neutralization of other immunosuppressive cells and factors in the tumor microenvironment.

MRI of sporadic Creutzfeldt-Jakob disease

The key MRI findings in five cases of sporadic Creutzfeldt-Jakob disease (CJD) are illustrated with four 'definite' and one 'probable' according to World Health Organization criteria. Close attention to fluid-attenuation inversion recovery and diffusion-weighted imaging sequences are important for diagnosis, noting especially restricted diffusion in cortical and deep grey matter. Our study and those of others show predominant cortical, caudate and thalamic involvement. This pattern is highly sensitive and specific for the diagnosis. Fluid-attenuation inversion recovery and diffusion-weighted imaging signal abnormality becomes progressively more extensive and bilateral as disease progresses, but may become less pronounced in end-stage disease because of atrophy.

Expanded murine regulatory T cells: Analysis of phenotype and function in contact hypersensitivity reactions

Regulatory T cells (Treg) exert suppressive functions in the periphery of the body for the maintenance of tolerance. The functional analysis of Treg is hampered by the fact that only small numbers (5%-10% among the CD4(+) T cells) of Treg exist in peripheral blood and tedious isolation methods further reduce the yield of high-purity Treg. We therefore set out to expand isolated murine Treg in ex vivo cultures with help of anti-CD3/anti-CD28 antibodies in the presence of IL-2. Our expansion-protocol described herein resulted in a 200-fold expansion of Treg and does not involve feeder cells, beads or other cellular compounds that would interfere with further in vivo use of the expanded cells. Expanded Treg could even be stored in liquid nitrogen and thawed without loss of function. Functional analysis revealed that expanded Treg are superior suppressors of T cell functions in vitro and in vivo and when applied in a model for contact hypersensitivity reactions, Treg were able to suppress the ear swelling reaction significantly. Thereby the expanded Treg home to secondary lymphoid organs in similar manner as observed for freshly isolated Treg. Accordingly, the expansion procedure does not effect the expression of specific homing markers. Thus, this protocol will facilitate the production of Treg as an "off-the-shelf reagent" and offers the possibility to explore the application of Treg as a cellular therapeutic in several allergic and autoimmune diseases.

The secreted beta-amyloid precursor protein ectodomain APPs alpha is sufficient to rescue the anatomical, behavioral, and electrophysiological abnormalities of APP-deficient mice

It is well established that the proteolytic processing of the beta-amyloid precursor protein (APP) generates beta-amyloid (Abeta), which plays a central role in the pathogenesis of Alzheimer's disease (AD). In contrast, the physiological role of APP and of its numerous proteolytic fragments and the question of whether a loss of these functions contributes to AD are still unknown. To address this question, we replaced the endogenous APP locus by gene-targeted alleles and generated two lines of knock-in mice that exclusively express APP deletion variants corresponding either to the secreted APP ectodomain (APPs alpha) or to a C-terminal (CT) truncation lacking the YENPTY interaction motif (APPdeltaCT15). Interestingly, the deltaCT15 deletion resulted in reduced turnover of holoAPP, increased cell surface expression, and strongly reduced Abeta levels in brain, likely because of reduced processing in the endocytic pathway. Most importantly, we demonstrate that in both APP knock-in lines the expression of APP N-terminal domains either grossly attenuated or completely rescued the prominent deficits of APP knock-out mice, such as reductions in brain and body weight, grip strength deficits, alterations in circadian locomotor activity, exploratory activity, and the impairment in spatial learning and long-term potentiation. Together, our data suggest that the APP C terminus is dispensable and that APPs alpha is sufficient to mediate the physiological functions of APP assessed by these tests.

Induction of immunosuppressive functions of dendritic cellsin vivo by CD4+CD25+ regulatory T cells: Role of B7-H3 expression and antigen presentation

Suppressive functions of CD4+CD25+ regulatory T cells (Treg) are mainly studied by their interaction with conventional T cells. However, there is evidence that Treg also interact with antigen-presenting cells (APC), leading to suppression of APC function in in vitro coculture systems. Studying the in vivo distribution of Treg after injection, we found that Treg are located in direct proximity to dendritic cells (DC) and affect their functional maturation status. After contact to Treg, DC up-regulate the inhibitory B7-H3 molecule and display reduced numbers of MHC-peptide complexes, leading to impaired T cell stimulatory function. When Treg-exposed DC were used to immunize animals against antigens, the DC failed to produce a robust immune response as compared to control DC. Thus, these data indicate that Treg are able to inhibit DC activation and produce an inhibitory phenotype of DC. Accordingly, Treg may recruit DC for the amplification of immunosuppression by restraining their maturation in vivo and inducing an immunosuppressive phenotype of DC.

Tolerogenic dendritic cells and regulatory T cells: a two-way relationship

At first glance, dendritic cells (DCs) and regulatory T cells (Tregs) do not have much in common. DCs are characterized by their unsurpassed T cell stimulatory capacity, whereas Tregs are marked by the ability to suppress proliferation of effector T cells. However, only mature/activated DCs stimulate T cell proliferation, whereas immature DCs induce Tregs. This provides a means by which peripheral tolerance is maintained: in the absence of inflammation and disease, DCs encounter apoptotic cells and "self" detritus in peripheral tissues. Thus, DCs constantly sample the peripheral environment and, accordingly, the presentation of "self" by these steady state DCs results in induction of suppressive Tregs. Vice versa, Tregs are able to affect DC development, preventing maturation and inducing IL-10, as well as immunosuppressive molecules of the B7-H family, in DCs. Therefore, these novel findings establish a mutual interaction between DCs and Tregs for the upkeep of immunosuppression: immature DCs induce Tregs and inversely Tregs prepare DCs to become immunosuppressive, thereby extending the immunosuppressive function of Tregs. The possible means of cellular interactions as well as the consequences for tolerance and immunity are discussed in this review.

Depletion of CD4+CD25+ human regulatory T cellsin vivo: Kinetics of Treg depletion and alterations in immune functionsin vivo andin vitro

The aim of this study was to investigate whether depletion of CD4(+)CD25(+) regulatory T cells (Treg) from melanoma patients affects immune responses against tumors. By application of recombinant IL-2-diphteria toxin fusion protein, also known as ONTAK, we were able to significantly reduce the frequency of Treg in peripheral blood, whereas other cell populations remained unaffected. The reduction of Treg started immediately after the first bolus of ONTAK with a dose of 5 microg ONTAK per kg bodyweight and lasted for 13 days with subsequent recovery thereafter. Successive ONTAK treatments further reduced the number of circulating Treg. Using the contact sensitizer DCP we show that all patients developed vast eczema after Treg depletion, whereas no or only mild eczematous reactions were detectable before ONTAK treatment. Corresponding induction of DCP-specific CD4(+) and CD8(+) T cells were detectable. Moreover, after immunization of ONTAK treated patients with tumor antigen peptides, MelanA/MART-1 and gp100, significant induction of peptide specific CD8(+) T cells could be observed in 90% of the patients treated. These cells displayed effector functions, as they were able to lyse peptide-pulsed target cells and secreted IFNgamma upon restimulation. In aggregate, our data indicate that ONTAK depletes Treg in vivo significantly, resulting in enhanced immune functions and substantial development of antigen-specific CD8(+) T cells in vaccinated individuals.

CD4+CD25+ regulatory T cells suppress contact hypersensitivity reactions by blocking influx of effector T cells into inflamed tissue

CD4+ CD25+ regulatory T cells (Treg) exert suppressive functions on effector T cells in vitro and in vivo. However, the exact cellular events that mediate this inhibitory action remain largely unclear. To elucidate these events, we used intravital microscopy in a model of contact hypersensitivity (CHS) and visualized the leukocyte-endothelium interaction at the site of antigen challenge in awake C57BL/6 mice. Injection of Treg i.v. into sensitized mice at the time of local hapten challenge significantly inhibited rolling and adhesion of endogenous leukocytes to the endothelium. A similar inhibition of leukocyte recruitment could be recorded after injection of Treg-derived tissue culture supernatant. Thus, these data indicate that soluble factors may account for the suppressive effects. Accordingly we found that IL-10, but not TGF-beta, was produced by Treg upon stimulation and that addition of anti-IL-10 antibodies abrogated the suppressive effects of Treg and tissue culture supernatant in CHS reactions. Moreover, CD4+ CD25+ T cells isolated from IL-10-/- mice were not able to suppress the immune response induced by hapten treatment in C57BL/6 mice. In conclusion, our data suggest that cytokine-dependent rather than cell-cell contact-dependent mechanisms play a pivotal role in the suppression of CHS reactions by Treg in vivo.

An investigation of FRAXA intermediate allele phenotype in a longitudinal sample

The FRAXA trinucleotide repeat at Xq27.3 gives rise to fragile X syndrome when fully expanded, and both premature ovarian failure (POF) and fragile X tremor and ataxia syndrome (FXTAS) when in the premutation range. Reports of phenotypic effects extending into the intermediate repeat range are inconsistent but some studies suggest that these smaller expansions predispose to special educational needs (SEN). This study utilises the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort to investigate cognitive and behavioural variables that might be associated with FRAXA intermediate alleles. The current study failed to find any strong evidence of association of FRAXA intermediate alleles with SEN, behavioural problems or cognitive difficulties. However, our findings illustrate some of the difficulties encountered in identifying individuals with SEN. The power to identify specific components of cognitive and behavioural difficulties was reduced due to elective drop-out, which is characteristic of longitudinal studies. Our findings demonstrate the non-random loss of participants from this cohort and highlight problems that may arise when such data are used in genetic association studies.

Decreased levels of interleukin-12p40 in the serum of patients with Whipple's disease

BACKGROUND

An impaired production of interleukin (IL)-12 and T cell interferon-gamma (IFN-gamma) of in vitro stimulated monocytes has been discussed as a pathogenic factor in Whipple's disease (WD). It is unclear whether this defect of cellular immunity is translated to the humoral immune system and to serum correlates.

METHODS

We analyzed the serum of 40 patients with Whipple's disease in various degrees of disease activity by sandwich enzyme-linked immunosorbent assay for differences in cytokine and cell adhesion molecule concentrations compared with age- and sex-matched controls.

RESULTS

We observed a highly significant reduction of IL-12p40 levels (patients, 0.18+/-0.05 ng/ml (mean+/-SEM); controls, 3.19+/-0.39 ng/ml; p<0.01) in all stages of disease activity, whereas the concentration of IL-12p70 was comparable with controls. Furthermore, we observed a slight decrease in tumour necrosis factor alpha (TNF-alpha) concentrations in the serum of patients (patients, 6.36+/-0.90 pg/ml; controls, 10.5+/-1.23 pg/ml; p<0,05). The levels of other cytokines such as IFN-gamma, IL-2, IL-13 and transforming growth factor beta, as well as soluble cell adhesion molecules lymphocyte function-associated antigen 3 and intercellular adhesion molecule 1, were not significantly different compared with controls. Levels of immunoglobulin G2 (IgG2) measured in the serum of WD patients were below normal in 24 of 29 patients and were even below the 95% confidence interval in 10 patients.

CONCLUSION

Our data demonstrate a persistent defect of the cellular immune response with decreased serum concentrations of IL-12p40 and TNF-alpha and decreased IgG2 levels in a large group of WD patients. These data support as in vivo finding the results obtained in previous investigations with stimulated monocytes/lymphocytes. The isolated decrease in IL-12p40 may hint at possible defects in the IL-12/IFN-gamma promoter system.

Presenilin-dependent transcriptional control of the Abeta-degrading enzyme neprilysin by intracellular domains of betaAPP and APLP

Amyloid beta-peptide (Abeta), which plays a central role in Alzheimer's disease, is generated by presenilin-dependent gamma-secretase cleavage of beta-amyloid precursor protein (betaAPP). We report that the presenilins (PS1 and PS2) also regulate Abeta degradation. Presenilin-deficient cells fail to degrade Abeta and have drastic reductions in the transcription, expression, and activity of neprilysin, a key Abeta-degrading enzyme. Neprilysin activity and expression are also lowered by gamma-secretase inhibitors and by PS1/PS2 deficiency in mouse brain. Neprilysin activity is restored by transient expression of PS1 or PS2 and by expression of the amyloid intracellular domain (AICD), which is cogenerated with Abeta, during gamma-secretase cleavage of betaAPP. Neprilysin gene promoters are transactivated by AICDs from APP-like proteins (APP, APLP1, and APLP2), but not by Abeta or by the gamma-secretase cleavage products of Notch, N- or E- cadherins. The presenilin-dependent regulation of neprilysin, mediated by AICDs, provides a physiological means to modulate Abeta levels with varying levels of gamma-secretase activity.

Immunosuppressive therapy in Whipple's disease patients is associated with the appearance of gastrointestinal manifestations

OBJECTIVES

Whipple's disease is a rare chronic disorder, which is caused by systemic infection with Tropheryma whipplei. The first symptom of Whipple's disease usually is a nondestructive polyarthritis resembling in many aspects seronegative rheumatoid arthritis. This polyarticular inflammatory arthropathy preceding the diagnosis of Whipple's disease for several years frequently is treated with nonsteroidal antiinflammatory drugs (NSAIDs) and with immunosuppressive therapy. There is evidence that altered immune functions play a role in the manifestation of the disease and that Whipple's disease is associated with opportunistic infections. We therefore asked whether immunosuppressive treatment for arthropathy may alter the course of Whipple's disease.

PATIENTS AND METHODS

In a series of 27 patients with Whipple's disease clinical data were documented and the patients were followed for 3-4 yr. The patients were classified into three groups according to their medication: (i) patients with immunosuppressive therapy preceding the diagnosis, (ii) patients with NSAIDs before diagnosis, and (iii) patients without such therapies.

RESULTS

Arthropathies occurred in the mean 8 yr before diagnosis and were the first symptom in 63% of the patients. Gastrointestinal involvement usually became evident later on and frequently led to the diagnosis of Whipple's disease. In patients with immunosuppressive treatment, diarrhea occurred in the median 4 months after the initiation of such therapy and diagnosis of Whipple's disease was made after another 2 months. In contrast, other medical treatments were not closely followed by the onset of diarrhea.

CONCLUSIONS

These results indicate an association between immunosuppressive therapy and the onset of diarrhea in Whipple's disease and thus support the concept that immunologic factors play a role in disease pathogenesis. Further investigation on the interaction of the immune system and Tropheryma whipplei infection are required to understand the factors contributing to the clinical manifestation of this rare disorder and possibly to introduce preventive interventions.

Cortical dysplasia resembling human type 2 lissencephaly in mice lacking all three APP family members

The Alzheimer's disease beta-amyloid precursor protein (APP) is a member of a larger gene family that includes the amyloid precursor-like proteins, termed APLP1 and APLP2. We previously documented that APLP2-/-APLP1-/- and APLP2-/-APP-/- mice die postnatally, while APLP1-/-APP-/- mice and single mutants were viable. We now report that mice lacking all three APP/APLP family members survive through embryonic development, and die shortly after birth. In contrast to double-mutant animals with perinatal lethality, 81% of triple mutants showed cranial abnormalities. In 68% of triple mutants, we observed cortical dysplasias characterized by focal ectopic neuroblasts that had migrated through the basal lamina and pial membrane, a phenotype that resembles human type II lissencephaly. Moreover, at E18.5 triple mutants showed a partial loss of cortical Cajal Retzius (CR) cells, suggesting that APP/APLPs play a crucial role in the survival of CR cells and neuronal adhesion. Collectively, our data reveal an essential role for APP family members in normal brain development and early postnatal survival.