Hybrid immunity to SARS-CoV-2 in patients with chronic lymphocytic leukemia

OBJECTIVE

Preventing severe COVID-19 remains a priority globally, particularly in the immunocompromised population. As shown in healthy individuals, immunity against SARS-CoV-2 can be yielded by previous infection, vaccination, or both (hybrid immunity). The objective of this observation study was to investigate hybrid immunity in patients with chronic lymphocytic leukemia (CLL).

METHODS/RESULTS

Blood samples of six patients with CLL were collected 55 days after fourth COVID-19 vaccination. All patients had a SARS-CoV-2 infection within 12 months before the second booster (fourth vaccination). SARS-CoV-2 spike receptor binding domain (RBD)-specific IgG antibodies were detectable in 6/6 (100.0%) CLL patients after four compared to 4/6 (66.7%) after three vaccinations. The median number of SARS-CoV-2 spike-specific T cells after repeated booster vaccination plus infection was 166 spot-forming cells (SFC) per million peripheral blood mononuclear cells. Overall, 5/5 (100%) studied patients showed a detectable increase in T cell activity.

CONCLUSION

Our data reveal an increase of cellular and humoral immune response in CLL patients after fourth COVID-19 vaccination combined with SARS-CoV-2 infection, even in those undergoing B cell-depleting treatment. Patients with prior vaccination failure now show a specific IgG response. Future research should explore the duration and effectiveness of hybrid immunity considering various factors like past infection and vaccination rates, types and numbers of doses, and emerging variants.

RTS,S/AS02A Malaria Vaccine-Induced IgG Responses Equally Recognize Native-Like Fucosylated and Nonfucosylated Plasmodium falciparum Circumsporozoite Proteins

The RTS,S/AS02A malaria vaccine is based on the Plasmodium falciparum circumsporozoite protein (PfCSP), which is O-fucosylated on the sporozoite surface. We determined whether RTS,S/AS02A-induced immunoglobulin G (IgG) antibodies recognize vaccine-like nonfucosylated PfCSP better than native-like fucosylated PfCSP. Similar to previous vaccine trials, RTS,S/AS02A vaccination induced high anti-PfCSP IgG levels associated with malaria protection. IgG recognition of nonfucosylated and fucosylated PfCSP was equivalent, suggesting that PfCSP fucosylation does not affect antibody recognition. Clinical Trials Registration. NCT00197041.

MVA-based vaccine candidates encoding the native or prefusion-stabilized SARS-CoV-2 spike reveal differential immunogenicity in humans

In response to the COVID-19 pandemic, multiple vaccines were developed using platforms such as viral vectors and mRNA technology. Here, we report humoral and cellular immunogenicity data from human phase 1 clinical trials investigating two recombinant Modified Vaccinia virus Ankara vaccine candidates, MVA-SARS-2-S and MVA-SARS-2-ST, encoding the native and the prefusion-stabilized SARS-CoV-2 spike protein, respectively. MVA-SARS-2-ST was more immunogenic than MVA-SARS-2-S, but both were less immunogenic compared to licensed mRNA- and ChAd-based vaccines in SARS-CoV-2 naïve individuals. In heterologous vaccination, previous MVA-SARS-2-S vaccination enhanced T cell functionality and MVA-SARS-2-ST boosted the frequency of T cells and S1-specific IgG levels when used as a third vaccination. While the vaccine candidate containing the prefusion-stabilized spike elicited predominantly S1-specific responses, immunity to the candidate with the native spike was skewed towards S2-specific responses. These data demonstrate how the spike antigen conformation, using the same viral vector, directly affects vaccine immunogenicity in humans.

Identification of a spike-specific CD8+ T cell epitope following vaccination against the Middle East respiratory syndrome coronavirus in humans

Licensed vaccines against the Middle East respiratory syndrome coronavirus (MERS-CoV), an emerging pathogen of concern, are lacking. The Modified Vaccinia virus Ankara vector-based vaccine MVA-MERS-S, expressing the MERS-CoV-spike glycoprotein (MERS-S), is one of three candidate vaccines in clinical development and elicits robust humoral and cellular immunity. Here, we identified for the first time a MERS-S-specific CD8+ T-cell epitope in an HLA-A*03:01/HLA-B*35:01-positive vaccinee using a screening assay, intracellular cytokine staining, and in silico epitope prediction. As evidence from MERS-CoV infection suggests a protective role of long-lasting CD8+ T-cell responses, the identification of epitopes will facilitate longitudinal analyses of vaccine-induced T-cell immunity.

Invasive Bacterial Infections of the Musculoskeletal and Central Nervous System during Pig Rearing: Detection Frequencies of Different Pathogens and Specific Streptococcus suis Genotypes

Locomotor and central nervous system disorders occur during pig rearing, but there is no systematic recording of the different causative agents in Germany. Joint and meningeal swabs, kidneys, lungs, and eight different lymph nodes per pig were cultured, and isolated pathogens were identified using polymerase chain reactions (PCRs). The cps and pathotype of Streptococcus suis (S. suis) isolates were determined using multiplex-PCR. S. suis was the most important pathogen in the infected joints (70.8%) and meningeal swabs (85.4%) and was most frequently detected in both sites in suckling and weaning piglets. To elucidate the possible portal of entry of S. suis, eight different lymph nodes from 201 pigs were examined in a prospective study. S. suis was detected in all examined lymph nodes (n = 1569), including the mesenteric lymph nodes (15.8%; n = 121/765), with cps 9 (37.2%; n = 147) and cps 2 (24.3%; n = 96) being the most dominating cps types. In piglets with a systemic S. suis infection, different lymph nodes are frequently infected with the invasive S. suis strain, which does not help clarify the portal of entry for S. suis.

Effect of 5 weeks of oral acetazolamide on patients with pulmonary vascular disease: A randomized, double-blind, cross-over trial

BACKGROUND

The carbonic anhydrase inhibitor acetazolamide stimulates ventilation through metabolic acidosis mediated by renal bicarbonate excretion. In animal models, acetazolamide attenuates acute hypoxia-induced pulmonary hypertension (PH), but its efficacy in treating patients with PH due to pulmonary vascular disease (PVD) is unknown.

METHODS

28 PVD patients (15 pulmonary arterial hypertension, 13 distal chronic thromboembolic PH), 13 women, mean±SD age 61.6±15.0 years stable on PVD medications, were randomised in a double-blind crossover protocol to 5 weeks acetazolamide (250mg b.i.d) or placebo separated by a ≥2 week washout period. Primary endpoint was the change in 6-minute walk distance (6MWD) at 5 weeks. Additional endpoints included safety, tolerability, WHO functional class, quality of life, arterial blood gases, and hemodynamics (by echocardiography).

RESULTS

Acetazolamide had no effect on 6MWD compared to placebo (treatment effect: mean change [95%CI] -18 [-40 to 4]m, p=0.102) but increased arterial blood oxygenation through hyperventilation induced by metabolic acidosis. Other measures including pulmonary hemodynamics were unchanged. No severe adverse effects occurred, side effects that occurred significantly more frequently with acetazolamide vs. placebo were change in taste (22/0%), paraesthesia (37/4%) and mild dyspnea (26/4%).

CONCLUSIONS

In patients with PVD, acetazolamide did not change 6MWD compared to placebo despite improved blood oxygenation. Some patients reported a tolerable increase in dyspnoea during acetazolamide treatment, related to hyperventilation, induced by the mild drug-induced metabolic acidosis. Our findings do not support the use of acetazolamide to improve exercise in patients with PVD at this dosing.

CLINICALTRIALS

GOV IDENTIFIER

NCT02755298.

Stabilized recombinant SARS-CoV-2 spike antigen enhances vaccine immunogenicity and protective capacity

The SARS-CoV-2 spike (S) glycoprotein is synthesized as a large precursor protein and must be activated by proteolytic cleavage into S1 and S2. A recombinant modified vaccinia virus Ankara (MVA) expressing native, full-length S protein (MVA-SARS-2-S) is currently under investigation as a candidate vaccine in phase I clinical studies. Initial results from immunogenicity monitoring revealed induction of S-specific antibodies binding to S2, but low-level antibody responses to the S1 domain. Follow-up investigations of native S antigen synthesis in MVA-SARS-2-S-infected cells revealed limited levels of S1 protein on the cell surface. In contrast, we found superior S1 cell surface presentation upon infection with a recombinant MVA expressing a stabilized version of SARS-CoV-2 S protein with an inactivated S1/S2 cleavage site and K986P and V987P mutations (MVA-SARS-2-ST). When comparing immunogenicity of MVA vector vaccines, mice vaccinated with MVA-SARS-2-ST mounted substantial levels of broadly reactive anti-S antibodies that effectively neutralized different SARS-CoV-2 variants. Importantly, intramuscular MVA-SARS-2-ST immunization of hamsters and mice resulted in potent immune responses upon challenge infection and protected from disease and severe lung pathology. Our results suggest that MVA-SARS-2-ST represents an improved clinical candidate vaccine and that the presence of plasma membrane-bound S1 is highly beneficial to induce protective antibody levels.

A new S. suis serotype 3 infection model in pigs: lack of effect of buprenorphine treatment to reduce distress

BACKGROUND

Streptoccocus suis (S. suis) is a major porcine pathogen causing meningitis, septicemia, arthritis and endocarditis. These diseases severely impair welfare of pigs. Experimental studies in pigs are important to better understand the pathogenesis and to identify protective antigens, as so far there is no vaccine available protecting against various serotypes (cps). Due to the severity of disease, application of appropriate refinement strategies in experimental S. suis infections is essential to reduce distress imposed on the piglets without jeopardizing the scientific output. The objectives of this study were to evaluate buprenorphine treatment as a refinement measure and serum cortisol levels as a distress read out parameter in a new S. suis cps3 infection model in pigs.

RESULTS

Intravenous application of 2 × 10⁸ CFU of S. suis cps3 (sly⁺, mrp⁺) to 6-week-old piglets led to severe morbidity in approximately 50% of the animals. Main pathological findings included suppurative meningoencephalitis and arthritis as well as fibrinosuppurative endocarditis. Buprenorphine treatment (0.05 mg/kg every 8 h) did not prevent signs of severe pain, high clinical scores, moderate to severe pathologies or high levels of serum cortisol in single severely affected piglets. Significant differences in the course of leukocytosis, induction of specific antibodies and bactericidal immunity were not recorded between groups with or w/o buprenorphine treatment. Of note, clinically unobtrusive piglets showed serum cortisol levels at 2 and 5 days post infectionem (dpi) comparable to the levels prior to infection with cps3. Cortisol levels in serum were significantly increased in piglets euthanized due to severe disease in comparison to clinically unobtrusive pigs.

CONCLUSIONS

Different clinical courses and pathologies are induced after intravenous challenge of piglets with 2 × 10⁸ CFU of this S. suis cps3 strain. The chosen protocol of buprenorphine application does not prevent severe distress in this infection model. Important parameters of the humoral immune response, such as the level of IgM binding to S. suis cps3, do not appear to be affected by buprenorphine treatment. Serum cortisol is a meaningful parameter to measure distress in piglets experimentally infected with S. suis and to evaluate refinement strategies. In this intravenous model, which includes close clinical monitoring and different humane endpoints, clinics and cortisol levels suggest convalescence in surviving piglets within 5 days following experimental infection.

TEMPus VoLA: The timed Epstein multi-pressure vessel at low accelerations

The field of planetary system formation relies extensively on our understanding of the aerodynamic interaction between gas and dust in protoplanetary disks. Of particular importance are the mechanisms triggering fluid instabilities and clumping of dust particles into aggregates, and their subsequent inclusion into planetesimals. We introduce the timed Epstein multi-pressure vessel at low accelerations, which is an experimental apparatus for the study of particle dynamics and rarefied gas under micro-gravity conditions. This facility contains three experiments dedicated to studying aerodynamic processes: (i) the development of pressure gradients due to collective particle-gas interaction, (ii) the drag coefficients of dust aggregates with variable particle-gas velocity, and (iii) the effect of dust on the profile of a shear flow and resultant onset of turbulence. The approach is innovative with respect to previous experiments because we access an untouched parameter space in terms of dust particle packing fraction, and Knudsen, Stokes, and Reynolds numbers. The mechanisms investigated are also relevant for our understanding of the emission of dust from active surfaces, such as cometary nuclei, and new experimental data will help interpreting previous datasets (Rosetta) and prepare future spacecraft observations (Comet Interceptor). We report on the performance of the experiments, which has been tested over the course of multiple flight campaigns. The project is now ready to benefit from additional flight campaigns, to cover a wide parameter space. The outcome will be a comprehensive framework to test models and numerical recipes for studying collective dust particle aerodynamics under space-like conditions.

SARS-CoV-2-specific cellular response following third COVID-19 vaccination in patients with chronic lymphocytic leukemia

Not available.

Selection for nonspecific adhesion is a driver of FimH evolution increasing Escherichia coli biofilm capacity

Bacterial interactions with surfaces rely on the coordinated expression of a vast repertoire of surface-exposed adhesins. However, how bacteria dynamically modulate their adhesion potential to achieve successful surface colonization is not yet well understood. Here, we investigated changes in adhesion capacity of an initially poorly adherent Escherichia coli strain using experimental evolution and positive selection for mutations improving adhesion and biofilm formation on abiotic surfaces. We showed that all identified evolved populations and clones acquired mutations located almost exclusively in the lectin domain of fimH, the gene coding for the α-d-mannose-specific tip adhesin of type 1 fimbriae, a key E. coli virulence factor. While most of these fimH mutants showed reduced mannose-binding ability, they all displayed enhanced binding to abiotic surfaces, indicating a trade-off between FimH-mediated specific and nonspecific adhesion properties. Several of the identified mutations were already reported in the FimH lectin domain of pathogenic and environmental E. coli, suggesting that, beyond pathoadaptation, FimH microevolution favoring nonspecific surface adhesion could constitute a selective advantage for natural E. coli isolates. Consistently, although E. coli deleted for the fim operon still evolves an increased adhesion capacity, mutants selected in the ∆fim background are outcompeted by fimH mutants revealing clonal interference for adhesion. Our study therefore provides insights into the plasticity of E. coli adhesion potential and shows that evolution of type 1 fimbriae is a major driver of the adaptation of natural E. coli to colonization.

Antibody conversion rates to SARS-CoV-2 in saliva from children attending summer schools in Barcelona, Spain

BACKGROUND

Surveillance tools to estimate viral transmission dynamics in young populations are essential to guide recommendations for school opening and management during viral epidemics. Ideally, sensitive techniques are required to detect low viral load exposures among asymptomatic children. We aimed to estimate SARS-CoV-2 infection rates in children and adult populations in a school-like environment during the initial COVID-19 pandemic waves using an antibody-based field-deployable and non-invasive approach.

METHODS

Saliva antibody conversion defined as ≥ 4-fold increase in IgM, IgA, and/or IgG levels to five SARS-CoV-2 antigens including spike and nucleocapsid constructs was evaluated in 1509 children and 396 adults by high-throughput Luminex assays in samples collected weekly in 22 summer schools and 2 pre-schools in 27 venues in Barcelona, Spain, from June 29th to July 31st, 2020.

RESULTS

Saliva antibody conversion between two visits over a 5-week period was 3.22% (49/1518) or 2.36% if accounting for potentially cross-reactive antibodies, six times higher than the cumulative infection rate (0.53%) assessed by weekly saliva RT-PCR screening. IgG conversion was higher in adults (2.94%, 11/374) than children (1.31%, 15/1144) (p=0.035), IgG and IgA levels moderately increased with age, and antibodies were higher in females. Most antibody converters increased both IgG and IgA antibodies but some augmented either IgG or IgA, with a faster decay over time for IgA than IgG. Nucleocapsid rather than spike was the main antigen target. Anti-spike antibodies were significantly higher in individuals not reporting symptoms than symptomatic individuals, suggesting a protective role against COVID-19.

CONCLUSION

Saliva antibody profiling including three isotypes and multiplexing antigens is a useful and user-friendlier tool for screening pediatric populations to detect low viral load exposures among children, particularly while they are not vaccinated and vulnerable to highly contagious variants, and to recommend public health policies during pandemics.

Infection induced SARS-CoV-2 seroprevalence and heterogeneity of antibody responses in a general population cohort study in Catalonia Spain

Sparse data exist on the complex natural immunity to SARS-CoV-2 at the population level. We applied a well-validated multiplex serology test in 5000 participants of a general population study in Catalonia in blood samples collected from end June to mid November 2020. Based on responses to fifteen isotype-antigen combinations, we detected a seroprevalence of 18.1% in adults (n = 4740), and modeled extrapolation to the general population of Catalonia indicated a 15.3% seroprevalence. Antibodies persisted up to 9 months after infection. Immune profiling of infected individuals revealed that with increasing severity of infection (asymptomatic, 1-3 symptoms, ≥ 4 symptoms, admitted to hospital/ICU), seroresponses were more robust and rich with a shift towards IgG over IgA and anti-spike over anti-nucleocapsid responses. Among seropositive participants, lower antibody levels were observed for those ≥ 60 years vs < 60 years old and smokers vs non-smokers. Overweight/obese participants vs normal weight had higher antibody levels. Adolescents (13-15 years old) (n = 260) showed a seroprevalence of 11.5%, were less likely to be tested seropositive compared to their parents and had dominant anti-spike rather than anti-nucleocapsid IgG responses. Our study provides an unbiased estimate of SARS-CoV-2 seroprevalence in Catalonia and new evidence on the durability and heterogeneity of post-infection immunity.

Survival patterns of Streptococcus suis serotypes 1 and 14 in porcine blood indicate cross-reactive bactericidal antibodies in naturally infected pigs

Streptococcus suis serotype (cps) 1 and cps14 have been detected in association with severe diseases such as meningitis and polyarthritis in pigs. Though these two cps are very similar, only cps14 is an important zoonotic agent in Asia and only cps1 is described to be associated with diseases in suckling piglets rather than weaning piglets. The main objective of this study was to assess restriction of survival of cps14 and cps1 in porcine blood by IgG and IgM putatively cross-reacting with these two cps. Furthermore, we differentiate recent European cps1/14 strains by agglutination, cpsK sequencing, MLST and virulence-associated gene profiling. Our data confirmed cps1 of clonal complex 1 as an important pathotype causing polyarthritis in suckling piglets in Europe. The experimental design included also bactericidal assays with blood samples drawn at different ages of piglets naturally infected with different S. suis cps types including cps1 but not cps14. We report survival of a cps1 and a cps14 strain (both of sequence type 1) in blood of suckling piglets with high levels of maternal IgG binding to the bacterial surface. In contrast, killing of cps1 and cps14 was recorded in older piglets due to an increase of IgM as demonstrated by specific cleavage of IgM. Heterologous absorption of antibodies with cps1 or cps14 is sufficient to significantly increase the survival of the other cps. In conclusion, IgM elicited by natural S. suis infection is crucial for killing of S. suis cps1 and cps14 in older weaning piglets and has most likely the potential to cross-react between cps1 and cps14.

[Suicide stigma and suicide prevention]

In many societies suicide was and is an extremely controversial topic. This review article outlines the historical background of social condemnation of suicidal thoughts and actions in the western world. It summarizes current research results about the consequences of suicide stigma for affected persons and its relevance for suicide prevention. Finally, the next steps in research and prevention are discussed. Over time and in different cultures, the societal judgement of suicide has greatly varied. During antiquity, some philosophers viewed suicide negatively and by the fifth century AD suicide was widely condemned by societies across the western world. Until today suicide remains a taboo topic in Germany and other countries. Current research showed that the social condemnation of suicidal thoughts and behavior (i.e. suicide stigma) is an additional stressor among persons who experience or have experienced suicidality and their relatives. Furthermore, suicide stigma is considered to be a central barrier to seeking help for and disclosure of suicidality. Despite its relevance for suicide prevention, only a few interventions to reduce suicide stigma among members of the general public and to support affected persons in dealing with suicide stigma exist.

From Stable to Lab-Investigating Key Factors for Sudden Deaths Caused by Streptococcus suis

Swine stocks are endemically infected with the major porcine pathogen Streptococcus (S.) suis. The factors governing the transition from colonizing S. suis residing in the tonsils and the exacerbation of disease have not yet been elucidated. We analyzed the sudden death of fattening pigs kept under extensive husbandry conditions in a zoo. The animals died suddenly of septic shock and showed disseminated intravascular coagulopathy. Genotypic and phenotypic characterizations of the isolated S. suis strains, a tonsillar isolate and an invasive cps type 2 strain, were conducted. Isolated S. suis from dead pigs belonged to cps type 2 strain ST28, whereas one tonsillar S. suis isolate harvested from a healthy animal belonged to ST1173. Neither S. suis growth, induction of neutrophil extracellular traps, nor survival in blood could explain the sudden deaths. Reconstituted blood assays with serum samples from pigs of different age groups from the zoo stock suggested varying protection of individuals against pathogenic cps type 2 strains especially in younger pigs. These findings highlight the benefit of further characterization of the causative strains in each case by sequence typing before autologous vaccine candidate selection.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Familial hypercholesterolaemia in patients with ischaemic stroke or transient ischaemic attack

BACKGROUND AND PURPOSE

Identification of patients with familial hypercholesterolaemia (FH) is a prerequisite for the appropriate management of their excess cardiovascular risk. It is currently unknown how many patients with acute ischaemic stroke or transient ischaemic attack (TIA) are affected by FH and whether systematic screening for FH is warranted in these patients.

METHODS

The prevalence of a clinical diagnosis of FH was estimated in a large representative series of patients with acute ischaemic stroke or TIA (ABCD2 score ≥ 3) using the Dutch Lipid Clinic Network Algorithm (DLCNA; possible FH ≥3, probable/definite FH ≥6).

RESULTS

Out of 1054 patients included in the present analysis, 14 had probable/definite FH (1.3%; 95% confidence interval 0.6-2.0) and 107 possible FH (10.2%; 8.4-12.0) corresponding to an overall prevalence of potential FH of 11.5%. Prevalences were even higher in patients with stroke/TIA manifestation before age 55 in men or 60 in women (3.1%, 0.6-5.6; and 13.1%, 8.3-17.9) and those with a prior history of cardiovascular disease (2.6%, 0.9-4.3; and 15.1%, 11.3-18.9). Of note, in two-thirds of our patients with probable/definite and possible FH, stroke or TIA was the initial clinical disease manifestation.

CONCLUSIONS

The frequency of potential FH, based on clinical criteria, in patients with acute ischaemic stroke or TIA was 11.5% and that of probable/definite FH (1.3%) was similar to recently reported counts for patients with acute coronary syndrome (1.6%). FH screening using the DLCNA is feasible in clinical routine and should be considered as part of the usual diagnostic work-up.

BedMachine v3: Complete Bed Topography and Ocean Bathymetry Mapping of Greenland From Multibeam Echo Sounding Combined With Mass Conservation

Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface, yielding major improvements over previous data sets, particularly in the marine-terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine-based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing.

Oligoclonal expansions of mucosal T cells in Crohn's disease predominate in NKG2D-expressing CD4 T cells

Crohn's disease (CD) is an inflammatory pathology of the mucosal intestine that results from uncontrolled immune response towards commensal microbes. Clonal expansions of T cells have been found in patients with CD suggesting an antigen-specific stimulation of pathogenic T cells. Here we show, using T-cell receptor repertoire analysis by real-time PCR, that oligoclonal expansions are found in both CD8+ and CD4+ T cells in the blood and intestinal mucosa of CD patients. The majority of CD4+ T-cell-expanded clones are CD4+NKG2D+ T cells. These clonal expansions were found in both inflamed and neighboring healthy tissue and were persisting during the course of the disease. The presence of these CD4+NKG2D+ T-cell clones at the macroscopically normal edge of the surgical resection might be predictive of inflammation relapse post surgery.

IL-22-producing CD4+ cells are depleted in actively inflamed colitis tissue

T helper type (Th17) cytokines such as interleukin (IL)-17A and IL-22 are important in maintaining mucosal barrier function and may be important in the pathogenesis of inflammatory bowel diseases (IBDs). Here, we analyzed cells from the colon of IBD patients and show that Crohn's disease (CD) patients had significantly elevated numbers of IL-17+, CD4+ cells compared with healthy controls and ulcerative colitis (UC) patients, but these numbers did not vary based on the inflammatory status of the mucosa. By contrast, UC patients had significantly reduced numbers of IL-22+ cells in actively inflamed tissues compared with both normal tissue and healthy controls. There was a selective increase in mono-IL-17-producing cells from the mucosa of UC patients with active inflammation together with increased expression of transforming growth factor (TGF)-β and c-Maf. Increasing concentrations of TGF-β in lamina propria mononuclear cell cultures significantly depleted Th22 cells, whereas anti-TGF-β antibodies increased IL-22 production. When mucosal microbiota was examined, depletion of Th22 cells in actively inflamed tissue was associated with reduced populations of Clostridiales and increased populations of Proteobacteria. These results suggest that increased TGF-β during active inflammation in UC may lead to the loss of Th22 cells in the human intestinal mucosa.

Impact of ceftriaxone de-restriction on the occurrence of ESBL-positive bacterial strains and antibiotic consumption

As a cost-saving measure, the Drug and Therapeutics Committee (DTC) removed ceftriaxone from the list of restricted antibiotics in May, 2008, which permitted its use as a first-line antibiotic. To evaluate the impact of this change, the occurrence of extended-spectrum beta-lactamase (ESBL)-positive bacterial strains and antibiotic consumption were monitored for 2 years before and after the intervention. In the post-intervention period, ceftriaxone utilization increased, while total antibiotic utilization did not change significantly. The utilization of all restricted antibiotics decreased (p <0.05) in the post-intervention period. Utilization of carbapenems increased (p <0.05), while utilization of quinolones increased nonsignificantly. The density of resistant ESBLs increased (p = 0.001) from 0.99 to 1.34 per 1000 bed-days from the pre- to the postintervention period. Ceftriaxone use was significantly correlated with ESBL occurrence (p <0.005). It can be concluded that ceftriaxone de-restriction increased the occurrence of ESBLs and the utilization of carbapemens.

Diagnosis and treatment of primary immunodeficiency disease in patients with gastrointestinal symptoms

An estimated 250,000 individuals in the Unites States have been diagnosed with a primary immunodeficiency disease (PIDD). Early diagnosis and treatment of PIDD are critical to minimizing morbidity and improving quality of life. Patients with certain subtypes of PIDD may present with gastrointestinal complaints such as chronic or acute diarrhea, malabsorption, gastrointestinal pain, and inflammatory bowel diseases. Therefore, gastroenterologists are well positioned to help identify patients with PIDD. The hallmarks of PIDD include recurrent or persistent infections, infections due to microorganisms that rarely cause significant disease in immunocompetent people, unusually severe or life-threatening infections, and either low or persistently high white blood cell counts. An assessment for PIDD involves detailed patient and family histories, a physical examination, and diagnostic screening tests. Immunoglobulin replacement therapy is the cornerstone of treatment for most subtypes of PIDD.

Association of the GABRD gene and childhood-onset mood disorders

The chromosome 1p36 region was previously indicated as a locus for susceptibility to recurrent major depressive disorder based on a linkage study in a sample of 497 sib pairs. We investigated the gamma-aminobutyric acid A (GABA(A)) delta receptor subunit gene, GABRD, as a susceptibility gene to childhood-onset mood disorders (COMD) because of substantial evidence implicating GABAergic dysfunction in mood disorders and the position of this gene near the 1p36 linkage region. Using a sample consisting of 645 Hungarian families with a child/adolescent proband diagnosed with a mood disorder with the onset of the first episode before age 15, we found some evidence for the association of two polymorphisms located within the gene, rs2376805 and rs2376803, as well as significant evidence for biased transmission of the haplotypes of these two markers (global chi(2) test for haplotypes = 12.746, 3 df, P = 0.0052). Furthermore, significant evidence of association was only observed in male subjects (n = 438) when the results were analyzed by sex (chi(2) = 9.000 1 df, P = 0.003 for rs2376805). This was in contrast with the previous linkage findings, as LOD scores exceeding 3 were only in female-female pairs in that study. These findings point to the GABRD gene as a susceptibility gene for COMD; however, this gene may not explain the previous linkage finding.

CXCL13 expression in the gut promotes accumulation of IL-22-producing lymphoid tissue-inducer cells, and formation of isolated lymphoid follicles

The chemokine CXCL13 is overexpressed in the intestine during inflammation. To mimic this condition, we created transgenic mice-expressing CXCL13 in intestinal epithelial cells. CXCL13 expression promoted a marked increase in the number of B cells in the lamina propria and an increase in the size and number of lymphoid follicles in the small intestine. Surprisingly, these changes were associated with a marked increase in the numbers of RORgammat(+)NKp46(-)CD3(-)CD4(+) and RORgammat(+)NKp46(+) cells. The RORgammat(+)NKp46(-)CD3(-)CD4(+) cells expressed CXCR5, the receptor for CXCL13, and other markers of lymphoid tissue-inducer cells, such as LTalpha, LTbeta, and TNF-related activation-induced cytokine (TRANCE). RORgammat(+)NKp46(-)CD3(-)CD4(+) gut LTi cells produced IL-22, a cytokine implicated in epithelial repair; and expressed the IL-23 receptor, a key regulator of IL-22 production. These results suggest that overexpression of CXCL13 in the intestine during inflammatory conditions favors mobilization of B cells and of LTi and NK cells with immunomodulatory and reparative functions.

Cytokine Genes TNF, IL1A, IL1B, IL6, IL1RN and IL10, and childhood-onset mood disorders

BACKGROUND/AIMS

Inflammatory cytokines induce a behavioral syndrome, known as sickness behavior, that strongly resembles symptoms typically seen in depression. This resemblance has led to the theory that an imbalance of inflammatory cytokine activity may be a contributing factor in depressive disorders. Support for this is found in multiple lines of evidence, such as the effects of cytokines on the activities of the hypothalamic-pituitary-adrenal axis, serotonin and brain-derived neurotrophic factor, and hippocampal function, all of which are implicated in the etiology of depression. In addition, associations between inflammatory activity and depressive symptomology have been documented in a number of studies, and the depressogenic effects of cytokine therapy are well known. Accordingly, given that depression has a substantial genetic basis, genes involved in the regulation of inflammatory cytokine activity are strong candidates for involvement in genetic susceptibility to depressive disorders. Here, we have tested 6 key genes of this type, TNF, IL1A, IL1B, IL6, IL1RN and IL10, as candidates for involvement in childhood-onset mood disorders.

METHODS

In this study of 384 families, each ascertained through a child with depression diagnosed before the age of 15 years, 11 polymorphisms of known or likely functional significance (coding and regulatory variants) were analyzed.

RESULTS

Testing for biased transmission of alleles from parents to their affected offspring, we found no evidence for an association between childhood-onset mood disorders and any of the polymorphisms, either individually or as haplotypes.

CONCLUSION

The present study does not support the involvement of the TNF, IL1A, IL1B, IL6, IL1RN and IL10 variants as major genetic risk factors contributing to early-onset mood disorders.

Early preservation of effector functions followed by eventual T cell memory depletion: a model for the delayed onset of the effect of thiopurines

OBJECTIVE

The onset of the effect of thiopurines is delayed for several months. The aim of this study was to investigate immune mechanisms for this delay.

METHODS

The effects of thiopurines on human peripheral blood T cells and on lamina propria lymphocytes were investigated for apoptosis induction by Annexin V/propidium iodide (PI) and for cytokine secretion by intracellular staining and ELISA assays. To investigate the mechanism of the effect of thiopurines in vivo, Balb/C mice were co-immunised with HEL/OVA (hen egg lysozyme/ovalbumin) antigens, and then repeatedly challenged by HEL only, while being treated by mercaptopurine or vehicle alone for either 4 or 20 weeks. The memory response of CD4+ splenocytes towards HEL/OVA was then determined by CFSE (carboxyfluorescein succinimidyl ester) dilution.

RESULTS

Thiopurines arrested the proliferation of stimulated T cells but did not enhance the apoptosis of either resting T cells or activated T cells until day 5 poststimulation. Despite the proliferation arrest, stimulated T cells successfully differentiated into effector cells, as evidenced by their capacity for proinflammatory cytokine secretion, potent adhesion and cytotoxicity. Prolonged mercaptopurine treatment of mice for 20 weeks selectively reduced the CD4+ memory response to a repeatedly encountered HEL antigen, but did not affect the T cell memory pool to the previously presented OVA antigen. A shorter, 4 weeks, treatment with mercaptopurine did not inhibit the memory response to either antigen.

CONCLUSIONS

T cells arrested from cycling by thiopurines can still differentiate into potent effector cells capable of propagating the inflammatory process. Thiopurine treatment results in depletion of antigen-specific memory T cells, but this effect is dependent upon repeated encounters with the antigen over a prolonged time course.

Early clinical experience with adalimumab in treatment of inflammatory bowel disease with infliximab-treated and naïve patients

BACKGROUND

Adalimumab, at an induction dose of 160/80 mg followed by 40 mg every other week is approved for treatment of refractory Crohn's disease (CD) and for patients with loss of response to infliximab.

AIM

To evaluate the indications for adalimumab, the proportion of inflammatory bowel disease patients who require dose escalation and to identify whether this strategy is effective in inducing or maintaining remission.

METHODS

Patients prescribed adalimumab for CD were identified and included for analysis, if they had follow-up of at least 6 weeks. Adalimumab dose was escalated if patients had return of symptoms prior to next dose. Clinical judgment was used to determine severity of disease. A second GI physician confirmed disease severity as determined by the first physician.

RESULTS

A total of 48 out of 60 patients met inclusion criteria. Adalimumab was used to treat CD in 47/48 (98%) and ulcerative colitis in one (2%). Most patients had moderate 30/48 (63%) or severe 17/48 (35%) disease. Prior infliximab exposure was present in 42/48 (88%). Adalimumab dose escalation occurred in 14/48 (29%) within an average time of 2.2 months (s.d. 1.5 months). A majority of patients who required dose escalation, nine of 14 (64%) did not improve clinically. Steroids could be discontinued in three of 16 (18.8%). Clinical improvement was noted in 21/48 (43.8%) and one of 48 (2%) patients achieved clinical remission. Adverse drug reactions necessitated drug discontinuation in four of 48 (8%) of patients.

CONCLUSIONS

This retrospective review from a single academic medical centre suggests that a minority of patients, who cannot be maintained on 40 mg every other week, of adalimumab benefit from an increased dose. This suggests the need for a treatment with an alternative mode of action in anti-TNF failures.

Immunophysiology of experimental food allergy

Animal models of food allergy have been used to identify mechanisms involved in the development of sensitization to food proteins as well as immunologic mechanisms of adverse reactions to allergen reexposure. To counteract the normal tolerant responses to antigen generated in the gastrointestinal tract, investigators have used mucosal adjuvants or manipulated the mucosal barrier, taken advantage of endogenous adjuvanticity of some food allergens, or bypassed the oral route and sensitized through the skin. Site of antigen uptake in the gastrointestinal tract is a critical factor in both sensitization and anaphylaxis, and antigen uptake can be facilitated by immunoglobulin-E (IgE)-antigen complexes binding to CD23 on the epithelial cell surface. Studies on systemic anaphylaxis or local gastrointestinal manifestations of food allergy in mice have highlighted the contribution of IgE, mast cells, and pathogenic Th2 lymphocytes in experimental food allergy.

Pasteurization of milk proteins promotes allergic sensitization by enhancing uptake through Peyer's patches

BACKGROUND

The underlying mechanisms responsible for allergic sensitization to food proteins remain elusive. To investigate the intrinsic properties (as well as the effect of pasteurization) of the milk proteins alpha-lactalbumin, beta-lactoglobulin and casein that promote the induction of milk allergy.

METHODS

Alteration of structure and immune-reactivity of native and pasteurized proteins was assessed by gel filtration and ELISA. Uptake of these proteins was compared in vitro and in vivo. The biological effect was assessed by orally sensitizing C3H/HeJ mice with milk proteins followed by a graded oral challenge. Required dose to induce anaphylaxis, symptoms and mean body temperature was recorded. Antigen-specific antibodies and cytokine production by splenocytes were analyzed.

RESULTS

Soluble beta-lactoglobulin and alpha-lactalbumin but not insoluble casein were readily transcytosed through enterocytes in vitro and in vivo. Pasteurization caused aggregation of beta-lactoglobulin and alpha-lactalbumin inhibiting uptake by intestinal epithelial cells in vitro and in vivo. Furthermore, aggregation redirected uptake to Peyer's patches, which promoted significantly higher Th2-associated antibody and cytokine production in mice than their native counterparts. Despite this only the soluble forms of beta-lactoglobulin and alpha-lactalbumin elicited anaphylaxis (following priming) when allergens were administered orally. Aggregated beta-lactoglobulin and alpha-lactalbumin as well as casein required systemic administration to induce anaphylaxis.

CONCLUSIONS

These results indicate that triggering of an anaphylactic response requires two phases (1) sensitization by aggregates through Peyer's patches and (2) efficient transfer of soluble protein across the epithelial barrier. As the majority of common food allergens tend to form aggregates, this may be of clinical importance.

Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas

Supermassive black holes (SMBHs) are a ubiquitous component of the nuclei of galaxies. It is normally assumed that after the merger of two massive galaxies, a SMBH binary will form, shrink because of stellar or gas dynamical processes, and ultimately coalesce by emitting a burst of gravitational waves. However, so far it has not been possible to show how two SMBHs bind during a galaxy merger with gas because of the difficulty of modeling a wide range of spatial scales. Here we report hydrodynamical simulations that track the formation of a SMBH binary down to scales of a few light years after the collision between two spiral galaxies. A massive, turbulent, nuclear gaseous disk arises as a result of the galaxy merger. The black holes form an eccentric binary in the disk in less than 1 million years as a result of the gravitational drag from the gas rather than from the stars.

Ratiometric dosing of irinotecan (IRI) and floxuridine (FLOX) in a phase I trial: A new approach for enhancing the activity of combination chemotherapy

2549

Background: Like many pairs of chemotherapy agents, the combination of IRI and FLOX displays ratio-dependent activity in vitro. CPX-1, a liposome formulation of IRI:FLOX, was developed to maintain a synergistic 1:1 molar ratio in vivo, was highly active in preclinical models, and was evaluated in a phase 1 trial (CLTR0104–101). Methods: Doses were escalated from 30U/m2 (1U= 1 mg IRI + 0.36 mg FLOX) to 270 U/m2 given on day 1 and 15 of each 28 day cycle. Adult patients (pts) with advanced solid tumors, ECOG PS<2, adequate bone marrow, liver, and renal function were eligible; 4 pts per cohort. After defining the MTD, additional pts with CRC were enrolled (extension phase). IRI completed greater than 12 months prior to this trial was allowed in the absence of resistance to IRI. PK was done on day 1 and 15 of the 1st cycle. Results: Safety: The dose escalation phase enrolled 24 pts in 6 cohorts and added 2 pts in the 5th cohort (210U/m2; the MTD) after noting dose limiting diarrhea (3 pts) and neutropenia (1 pt) including one death from dehydration and renal failure due to prolonged diarrhea (gr3) & vomiting (gr2) at 270U/m2. An additional 7 pts with CRC received 210U/m2 in the extension phase. Grade 3/4 adverse events included diarrhea, nausea, vomiting, neutropenia and thrombocytopenia with most occurring at 270U/m2. No new toxicities were observed for this combination. Response: 30/33 pts were evaluable with 2 confirmed PRs (NSCLC and CRC), 21 SD and 7 PD. Median PFS was 5.4 mos. (0.3–11.8 mos.) in 15 pts w/CRC. PK: All pts maintained synergistic plasma IRI:FLOX ratios for 24h. IRI and FLOX AUCs (0-inf) were greater for CPX-1 than expected for conventional drugs. AUCs for SN-38 and 5FU at 210U/m2 were 0.8 ± 0.1 and 10 ± 8.7 μg-hr/mL, respectively, indicating bioavailability for both drugs. Conclusion: CPX-1 was well tolerated in the outpatient setting and evidence of anti-tumor activity was obtained. This is the first clinical evaluation of ratiometric dosing in which a synergistic drug ratio, pre-selected in vitro based on optimal anti-tumor activity, was maintained systemically to enhance therapeutic benefit.

[Table: see text]

Early gas stripping as the origin of the darkest galaxies in the Universe

The known galaxies most dominated by dark matter (Draco, Ursa Minor and Andromeda IX) are satellites of the Milky Way and the Andromeda galaxies. They are members of a class of faint galaxies, devoid of gas, known as dwarf spheroidals, and have by far the highest ratio of dark to luminous matter. None of the models proposed to unravel their origin can simultaneously explain their exceptional dark matter content and their proximity to a much larger galaxy. Here we report simulations showing that the progenitors of these galaxies were probably gas-dominated dwarf galaxies that became satellites of a larger galaxy earlier than the other dwarf spheroidals. We find that a combination of tidal shocks and ram pressure swept away the entire gas content of such progenitors about ten billion years ago because heating by the cosmic ultraviolet background kept the gas loosely bound: a tiny stellar component embedded in a relatively massive dark halo survived until today. All luminous galaxies should be surrounded by a few extremely dark-matter-dominated dwarf spheroidal satellites, and these should have the shortest orbital periods among dwarf spheroidals because they were accreted early.

Phase 1 study of CPX-1, a fixed ratio formulation of irinotecan (IRI) and floxuridine (FLOX), in patients with advanced solid tumors

2014

Background: In vitro studies have shown that varying the ratio of individual agents in drug combinations can result in synergistic, additive or antagonistic activity against tumor cells. CPX-1 is a liposomal formulation of IRI and FLOX in a fixed 1:1 molar ratio which was selected as optimal in vitro and confirmed to be synergistic in vivo in preclinical tumor models. CPX-1 overcomes the dissimilar pharmacokinetics (PK) of the individual drugs, enables sustained maintenance of this ratio after IV administration, and was evaluated in a Phase I open-label, dose-escalation study. Methods: Starting dose was 30 U/m2 (1 Unit of CPX-1 contains 1 mg IRI + 0.36 mg FLOX) given on day 1 and 15 of each 28-day cycle. Dose escalation was by modified Fibonacci with 4 subjects/cohort. Eligibility included: ≥ 18 yo; advanced solid tumor; ECOG PS ≤ 2; adequate bone marrow/liver/renal function. PK analysis was done on day 1 and 15 of the first cycle. Results: 26 subjects (16M:10F), median age 54.5 y (21–72), all with prior therapy, enrolled in 6 cohorts with the 5th cohort expanded to 6 subjects. Diagnoses: 8 colorectal, 3 pancreatic, 3 ovarian, 2 breast, 2 gastric, 2 esophageal, 2 sarcomas, 1 renal cell, 1 prostate, 1 NSCLC and 1 sphenoid sinus. Response: 20 subjects evaluable: 2 confirmed PRs (NSCLC 8+ wks; Colon 13+ wks, in a patient with prior IRI exposure) and 13 with SD (8–24+wks). Safety: DLTs were observed at the 6th dose level: 4 subjects with DLTs: 3 diarrhea (one resulting in death due to dehydration/ARF) and one neutropenia. Other possibly related grade 3 and 4 events included one each of: grade 3 diarrhea, grade 3 vomiting, grade 3 neutropenia, grade 3 fatigue, grade 3 compression fracture and arthralgia and pulmonary embolism grade 4. PK: In all 14 subjects analyzed to date the 1:1 molar ratio of IRI to FLOX was maintained for 24 hours and metabolites 5-FU and SN-38 were present in the plasma. Conclusions: CPX-1 represents a new approach to developing drug combinations in which drug ratios are pre-selected in vitro based on optimal antitumor activity and maintained systemically through pharmacokinetic control. Phase 2 studies are planned with a recommended dose of 210U/m2 of CPX-1.

[Table: see text]