Mapping of novel peptides of WT-1 and presenting HLA alleles that induce epitope-specific HLA-restricted T cells with cytotoxic activity against WT-1+ leukemias

The Wilms tumor protein (WT-1) is widely recognized as a tumor antigen that is expressed differentially by several malignancies. However, WT-1 peptides known to induce tumoricidal T cells are few. In the present study, we evaluated T-cell responses of 56 healthy donors to in vitro sensitization with autologous APCs loaded with a pool of overlapping 15-mer peptides spanning the sequence of WT-1. Thereafter, we mapped the WT-1 peptides eliciting responses in each individual, defined the immunogenic peptides, and identified their presenting HLA alleles. We report 41 previously unreported epitopes of WT-1: 5 presented by class II and 36 by class I alleles, including 10 that could be presented by more than 1 class I allele. IFNγ(+) T cells responding to 98% of the class I and 60% of the class II epitopes exhibited HLA-restricted cytotoxicity against peptide-loaded targets. T cells specific for 36 WT-1 peptides were evaluable for leukemocidal activity, of which 27 (75%) lysed WT-1(+) leukemic targets sharing their restricting HLA allele. Each epitope identified induced T-cell responses in most donors sharing the epitopes' presenting allele; these responses often exceeded responses to flanking peptides predicted to be more immunogenic. This series of immunogenic epitopes of WT-1 should prove useful for immunotherapies targeting WT-1(+) malignancies.     

Amyloid beta deregulates astroglial mGluR5‐mediated calcium signaling via calcineurin and Nf‐kB

The amyloid hypothesis of Alzheimer's disease (AD) suggests that soluble amyloid β (Aβ) is an initiator of a cascade of events eventually leading to neurodegeneration. Recently, we reported that Aβ deranged Ca²⁺ homeostasis specifically in hippocampal astrocytes by targeting key elements of Ca²⁺ signaling, such as mGluR5 and IP₃R1. In the present study, we dissect a cascade of signaling events by which Aβ deregulates glial Ca²⁺: (i) 100 nM Aβ leads to an increase in cytosolic calcium after 4–6 h of treatment; (ii) mGluR5 is increased after 24 h of treatment; (iii) this increase is blocked by inhibitors of calcineurin (CaN) and NF‐kB. Furthermore, we show that Aβ treatment of glial cells leads to de‐phosphorylation of Bcl10 and an increased CaN‐Bcl10 interaction. Last, mGluR5 staining is augmented in hippocampal astrocytes of AD patients in proximity of Aβ plaques and co‐localizes with nuclear accumulation of the p65 NF‐kB subunit and increased staining of CaNAα. Taken together our data suggest that nanomolar [Aβ] deregulates Ca²⁺ homeostasis via CaN and its downstream target NF‐kB, possibly via the cross‐talk of Bcl10 in hippocampal astrocytes.     

Human regulatory T cells are selectively activated by low‐dose application of the CD28 superagonist TGN1412/TAB08

CD28 superagonists (CD28SAs) are potent T‐cell‐activating monoclonal antibodies (mAbs). In contrast to their benign behavior and marked therapeutic efficacy as activators of regulatory T (Treg) cells in preclinical rodent models, a phase I trial of the human CD28SA TGN1412 (now called TAB08) in 2006 resulted in a life‐threatening cytokine release syndrome (CRS). We studied TAB08‐mediated Treg‐cell activation in a recently developed in vitro system of human PBMCs, which also reproduces the CRS experienced by the healthy volunteers. We show that just as in rodents, CD28SAs are potent activators and expanders of Treg cells from healthy donors and rheumatoid arthritis patients, even under effective blockade of pro‐inflammatory cytokine release by a corticosteroid. Moreover, CD28SA titration identifies a dose range where pro‐inflammatory cytokine secretion from conventional T cells is absent while appreciable Treg‐cell activation is maintained. Finally, we report that low‐dose application of TAB08 to healthy volunteers results in dose‐dependent systemic release of the Treg‐cell signature cytokine IL‐10 in the absence of the pro‐inflammatory factors associated with the CRS of the 2006 TGN1412 study. These results demonstrate the potential of appropriately dosed CD28SA and corticosteroid comedication to mobilize human Treg cells for the treatment of autoimmune and inflammatory conditions.     

No interactions between previously associated 2-hour glucose gene variants and physical activity or BMI on 2-hour glucose levels

Gene-lifestyle interactions have been suggested to contribute to the development of type 2 diabetes. Glucose levels 2 h after a standard 75-g glucose challenge are used to diagnose diabetes and are associated with both genetic and lifestyle factors. However, whether these factors interact to determine 2-h glucose levels is unknown. We meta-analyzed single nucleotide polymorphism (SNP) × BMI and SNP × physical activity (PA) interaction regression models for five SNPs previously associated with 2-h glucose levels from up to 22 studies comprising 54,884 individuals without diabetes. PA levels were dichotomized, with individuals below the first quintile classified as inactive (20%) and the remainder as active (80%). BMI was considered a continuous trait. Inactive individuals had higher 2-h glucose levels than active individuals (β = 0.22 mmol/L [95% CI 0.13-0.31], P = 1.63 × 10(-6)). All SNPs were associated with 2-h glucose (β = 0.06-0.12 mmol/allele, P ≤ 1.53 × 10(-7)), but no significant interactions were found with PA (P > 0.18) or BMI (P ≥ 0.04). In this large study of gene-lifestyle interaction, we observed no interactions between genetic and lifestyle factors, both of which were associated with 2-h glucose. It is perhaps unlikely that top loci from genome-wide association studies will exhibit strong subgroup-specific effects, and may not, therefore, make the best candidates for the study of interactions.     

Contraceptive sterilization among married adults: national data on who chooses vasectomy and tubal sterilization

BackgroundVasectomy has been found to be a highly cost-effective contraceptive method. For couples, tubal sterilization and vasectomy have the same result, but the two methods are used by different segments of the population.Study designWe conducted an analysis of data from male and female samples of the 2006–2008 National Survey of Family Growth, nationally representative samples of men and women in the United States aged 15–44 years.ResultsAmong married men, 13.1% reported vasectomies (95% confidence interval 10.4%–16.3%), compared to 21.1% (17.8%–24.9%) of married women who reported tubal sterilizations. Men with higher education and income had greater prevalence of vasectomy than those less educated, while women with lower education and income had the highest prevalence of tubal sterilization.ConclusionsEfforts to promote vasectomy use need to understand the reasons behind these differences. Increasing the availability and use of vasectomy will require education about its benefits.     

Laser speckle imaging of intra organ drug distribution

Laminar flow in arteries causes streaming and uneven distribution of infused agents within the organ. This may lead to misinterpretation of experimental results and affect treatment outcomes. We monitor dynamical changes of superficial cortical blood flow in the rat kidney following different routes of administration of the vasoconstrictor angiotensin II. Our analysis reveals the appearance of large scale oscillations of the blood flow caused by inhomogeneous intra organ drug distribution.OCIS codes: (120.6150) Speckle imaging, (170.1470) Blood or tissue constituent monitoring, (170.5380) Physiology