Human large granular lymphocytes contain an esterase activity usually considered as specific for the myeloid series.

A cytochemical marker such as alpha-naphthyl acetate esterase (ANAE) has been found useful for the morphological identification of the subset of T lymphocytes having receptors for Fcμ (TM cells). ANAE reaction on TM cells gives a typical pattern of one to four positive spots, whereas this pattern is not found on T cells with receptors for Fcγ (TG cells). ANAE is abundant in monocytes but not detectable in granulocytes. Herein another type of esterase activity, naphthol-AS-D chloroacetate esterase (NCAE), is described; it is known to be abundant in granulocytes and was found to give a specific pattern of reactivity with the subpopulation of large granular lymphocytes (LGL). This pattern of fine granular staining was observed not only on LGL present in the TG cell subpopulation but also in LGL present in the non-T, non-B cells. Fractions of peripheral blood mononuclear cells which were ènriched up to 80% in LGL by Percoll discontinuous density gradient gave a similar percentage of specific NCAE pattern. In addition, among the different fractions from Percoll gradient, there was a good correlation (r = 0.94) between the number of NCAE-positive cells and the natural killer activity against the natural killer susceptible K562 target cells. It will be important to determine whether or not this enzymatic activity plays a role in the cytotoxic activities of LGL.

Growth arrest-specific gene 6 » (Gas6) as an intra-hospital mortality predictor for patients in septic shock

Aim: Gas6 is known to be elevated in sepsis, correlating with the severity of infection and¦organ failure. We aimed to investigate the performance of Gas6 plasma levels at¦admission to predict the risk of mortality in a cohort of septic patients.¦Methods: We used prospectively collected data and plasma samples from the "Sepsis¦Cohorte Romande". Gas6 level was measured by ELISA at admission and expressed in¦percentage relative to its level in a pool of normal plasma.¦Results: Non-survivors (n=21) presented higher Gas6 levels than survivors (n=73) (median¦258% vs 164%, IQR 194 and 117 respectively) (p=0.0027). Gas6 correlated positively with¦different cytokines and was the best mortality predictor, as shown by the ROC curves area.¦In patients with septic shock (n=66), using 249% as a cut-off value, Gas6 measurement¦had a specificity of 67% and a sensitivity of 81% for predicting mortality. ROC curve area¦was 0.75. Positive and negative predictive values were 57% and 87%, respectively.¦Conclusion: Thus, Gas6 plasma level at admission might be a useful tool to predict¦mortality in patients with septic shock. Although Gas6 hold promise as an early sepsis¦marker, its precise implication in sepsis remains to be elucidated. Our observation should¦be further investigated in larger prospective clinical trials.

A fish-specific transposable element shapes the repertoire of p53 target genes in zebrafish.

Transposable elements, as major components of most eukaryotic organisms' genomes, define their structural organization and plasticity. They supply host genomes with functional elements, for example, binding sites of the pleiotropic master transcription factor p53 were identified in LINE1, Alu and LTR repeats in the human genome. Similarly, in this report we reveal the role of zebrafish (Danio rerio) EnSpmN6_DR non-autonomous DNA transposon in shaping the repertoire of the p53 target genes. The multiple copies of EnSpmN6_DR and their embedded p53 responsive elements drive in several instances p53-dependent transcriptional modulation of the adjacent gene, whose human orthologs were frequently previously annotated as p53 targets. These transposons define predominantly a set of target genes whose human orthologs contribute to neuronal morphogenesis, axonogenesis, synaptic transmission and the regulation of programmed cell death. Consistent with these biological functions the orthologs of the EnSpmN6_DR-colonized loci are enriched for genes expressed in the amygdala, the hippocampus and the brain cortex. Our data pinpoint a remarkable example of convergent evolution: the exaptation of lineage-specific transposons to shape p53-regulated neuronal morphogenesis-related pathways in both a hominid and a teleost fish.

Boosting of Replication Competent NYVAC Primed HIV-1-Specific T-Cell Responses by HIV Synthetic Long Peptides (SLP)

Background: To enhance the induction of insert specific immune responses, a new generation of replication competent poxvirus vectors was designed and evaluated against non-replicating poxvirus vectors in a HIV vaccine study in non human primates.Methods: Rhesus macaques were immunized with either the non-replicating variant NYVAC-GagPolNef HIV-1 clade C or the replicating NYVAC-GagPolNef-C-KC, boosted with HIVGag- PolEnv-SLP and immune responses were monitored.Results: Gag-specific T-cell responses were only detected in animals immunized with the replicating NYVAC-GagPolNef-C-KC variant. Further enhancement and broadening of the immune response was studied by boosting the animals with novel T-cell immunogens HIVconsv synthetic long peptides (SLP), which direct vaccine-induced responses to the most conserved regions of HIV and contain both CD4 T-helper and CD8 CTL epitopes. The adjuvanted (Montanide ISA-720) SLP divided into subpools and delivered into anatomically separate sites enhanced the Gag-specific T-cell responses in 4 out of 6 animals, to more than 1000 SFC/106 PBMC in some animals. Furthermore, the SLP immunization broadened the immune response in 4 out of 6 animals to multiple Pol epitopes. Even Env-specific responses, to which the animals had not been primed, were induced by SLP in 2 out of 6 animals.Conclusion: This new immunization strategy of priming with replicating competent poxvirus NYVAC-HIVGagPolNef and boosting with HIVGagPolEnv-SLP, induced strong and broad Tcell responses and provides a promising new HIV vaccine approach. This study was performed within the Poxvirus T-cell Vaccine Discovery Consortium (PTVDC) which is part of the CAVD program.

Testosterone: a specific competitive antagonist of aldosterone in the toad bladder.

Testosterone (100 nM to 40 microM) antagonized the effect of aldosterone (10 nM) on Na+ transport in the toad bladder measured in vitro as short-circuit current (SCC). Half-maximal inhibition occurred at an antagonist-agonist molar ratio of 150:1. The antagonist action of testosterone was reversed by addition of more aldosterone. The antagonism was specific in the sense that testosterone (20 microM) did not inhibit the response of the SCC to oxytocin (50 mU/ml). By itself, testosterone (up to 20 microM) had no agonist activity on base-line SCC. Finally, testosterone (500 nM to 20 microM) specifically displaced [3H]aldosterone (5 nm) from its cytoplasmic and nuclear binding sites in bladders incubated in vitro at 25 or 0 degrees C and labeled at steady state. There was a significant linear correlation between the effect of testosterone on the aldosterone-dependent SCC and its effect on [3H]aldosterone binding sites in the cytoplasm and in the nucleus. We conclude that 1) testosterone is a specific competitive antagonist of aldosterone, and 2) [3H]aldosterone nuclear and cytoplasmic binding sites could be mineralocorticoid receptors, mediating the action of aldosterone on Na+ transport.

Three-dimensional patient-specific dosimetry in radioimmunotherapy with 90Y-ibritumomab-tiuxetan.

Aim of the present article was to perform three-dimensional (3D) single photon emission tomography-based dosimetry in radioimmunotherapy (RIT) with (90)Y-ibritumomab-tiuxetan. A custom MATLAB-based code was used to elaborate 3D images and to compare average 3D doses to lesions and to organs at risk (OARs) with those obtained with planar (2D) dosimetry. Our 3D dosimetry procedure was validated through preliminary phantom studies using a body phantom consisting of a lung insert and six spheres with various sizes. In phantom study, the accuracy of dose determination of our imaging protocol decreased when the object volume decreased below 5 mL, approximately. The poorest results were obtained for the 2.58 mL and 1.30 mL spheres where the dose error evaluated on corrected images with regard to the theoretical dose value was -12.97% and -18.69%, respectively. Our 3D dosimetry protocol was subsequently applied on four patients before RIT with (90)Y-ibritumomab-tiuxetan for a total of 5 lesions and 4 OARs (2 livers, 2 spleens). In patient study, without the implementation of volume recovery technique, tumor absorbed doses calculated with the voxel-based approach were systematically lower than those calculated with the planar protocol, with average underestimation of -39% (range from -13.1% to -62.7%). After volume recovery, dose differences reduce significantly, with average deviation of -14.2% (range from -38.7.4% to +3.4%, 1 overestimation, 4 underestimations). Organ dosimetry in one case overestimated, in the other underestimated the dose delivered to liver and spleen. However, both for 2D and 3D approach, absorbed doses to organs per unit administered activity are comparable with most recent literature findings.

Functional avidity of tumor antigen-specific CTL recognition directly correlates with the stability of MHC/peptide multimer binding to TCR.

Avidity of Ag recognition by tumor-specific T cells is one of the main parameters that determines the potency of a tumor rejection Ag. In this study we show that the relative efficiency of staining of tumor Ag-specific T lymphocytes with the corresponding fluorescent MHC class I/peptide multimeric complexes can considerably vary with staining conditions and does not necessarily correlate with avidity of Ag recognition. Instead, we found a clear correlation between avidity of Ag recognition and the stability of MHC class I/peptide multimeric complexes interaction with TCR as measured in dissociation kinetic experiments. These findings are relevant for both identification and isolation of tumor-reactive CTL.

Comparative genomics of chemosensory protein genes reveals rapid evolution and positive selection in ant-specific duplicates.

Gene duplications can have a major role in adaptation, and gene families underlying chemosensation are particularly interesting due to their essential role in chemical recognition of mates, predators and food resources. Social insects add yet another dimension to the study of chemosensory genomics, as the key components of their social life rely on chemical communication. Still, chemosensory gene families are little studied in social insects. Here we annotated chemosensory protein (CSP) genes from seven ant genomes and studied their evolution. The number of functional CSP genes ranges from 11 to 21 depending on species, and the estimated rates of gene birth and death indicate high turnover of genes. Ant CSP genes include seven conservative orthologous groups present in all the ants, and a group of genes that has expanded independently in different ant lineages. Interestingly, the expanded group of genes has a differing mode of evolution from the orthologous groups. The expanded group shows rapid evolution as indicated by a high dN/dS (nonsynonymous to synonymous changes) ratio, several sites under positive selection and many pseudogenes, whereas the genes in the seven orthologous groups evolve slowly under purifying selection and include only one pseudogene. These results show that adaptive changes have played a role in ant CSP evolution. The expanded group of ant-specific genes is phylogenetically close to a conservative orthologous group CSP7, which includes genes known to be involved in ant nestmate recognition, raising an interesting possibility that the expanded CSPs function in ant chemical communication.

The heat shock response in moss plants is regulated by specific calcium-permeable channels in the plasma membrane.

Land plants are prone to strong thermal variations and must therefore sense early moderate temperature increments to induce appropriate cellular defenses, such as molecular chaperones, in anticipation of upcoming noxious temperatures. To investigate how plants perceive mild changes in ambient temperature, we monitored in recombinant lines of the moss Physcomitrella patens the activation of a heat-inducible promoter, the integrity of a thermolabile enzyme, and the fluctuations of cytoplasmic calcium. Mild temperature increments, or isothermal treatments with membrane fluidizers or Hsp90 inhibitors, induced a heat shock response (HSR) that critically depended on a preceding Ca(2+) transient through the plasma membrane. Electrophysiological experiments revealed the presence of a Ca(2+)-permeable channel in the plasma membrane that is transiently activated by mild temperature increments or chemical perturbations of membrane fluidity. The amplitude of the Ca(2+) influx during the first minutes of a temperature stress modulated the intensity of the HSR, and Ca(2+) channel blockers prevented HSR and the onset of thermotolerance. Our data suggest that early sensing of mild temperature increments occurs at the plasma membrane of plant cells independently from cytosolic protein unfolding. The heat signal is translated into an effective HSR by way of a specific membrane-regulated Ca(2+) influx, leading to thermotolerance.

In vivo targeting of an anti-tumor antibody coupled to antigenic MHC class I complexes induces specific growth inhibition and regression of established syngeneic tumor grafts.

The concept of antibody-mediated targeting of antigenic MHC/peptide complexes on tumor cells in order to sensitize them to T-lymphocyte cytotoxicity represents an attractive new immunotherapy strategy. In vitro experiments have shown that an antibody chemically conjugated or fused to monomeric MHC/peptide can be oligomerized on the surface of tumor cells, rendering them susceptible to efficient lysis by MHC-peptide restricted specific T-cell clones. However, this strategy has not yet been tested entirely in vivo in immunocompetent animals. To this aim, we took advantage of OT-1 mice which have a transgenic T-cell receptor specific for the ovalbumin (ova) immunodominant peptide (257-264) expressed in the context of the MHC class I H-2K(b). We prepared and characterized conjugates between the Fab' fragment from a high-affinity monoclonal antibody to carcinoembryonic antigen (CEA) and the H-2K(b) /ova peptide complex. First, we showed in OT-1 mice that the grafting and growth of a syngeneic colon carcinoma line transfected with CEA could be specifically inhibited by systemic injections of the conjugate. Next, using CEA transgenic C57BL/6 mice adoptively transferred with OT-1 spleen cells and immunized with ovalbumin, we demonstrated that systemic injections of the anti-CEA-H-2K(b) /ova conjugate could induce specific growth inhibition and regression of well-established, palpable subcutaneous grafts from the syngeneic CEA-transfected colon carcinoma line. These results, obtained in a well-characterized syngeneic carcinoma model, demonstrate that the antibody-MHC/peptide strategy can function in vivo. Further preclinical experimental studies, using an anti-viral T-cell response, will be performed before this new form of immunotherapy can be considered for clinical use.

Should we await IFN-free regimens to treat HCV genotype 1 treatment-naive patients? A cost-effectiveness analysis (ANRS 95141).

BACKGROUND & AIMS: In treatment-naive patients mono-infected with genotype 1 chronic HCV, treatments with telaprevir/boceprevir (TVR/BOC)-based triple therapy are standard-of-care. However, more efficacious direct-acting antivirals (IFN-based new DAAs) are available and interferon-free (IFN-free) regimens are imminent (2015). METHODS: A mathematical model estimated quality-adjusted life years, cost and incremental cost-effectiveness ratios of (i) IFN-based new DAAs vs. TVR/BOC-based triple therapy; and (ii) IFN-based new DAAs initiation strategies, given that IFN-free regimens are imminent. The sustained virological response in F3-4/F0-2 was 71/89% with IFN-based new DAAs, 85/95% with IFN-free regimens, vs. 64/80% with TVR/BOC-based triple therapy. Serious adverse events leading to discontinuation were taken as: 0-0.6% with IFN-based new DAAs, 0% with IFN-free regimens, vs. 1-10% with TVR/BOC-based triple therapy. Costs were euro60,000 for 12weeks of IFN-based new DAAs and two times higher for IFN-free regimens. RESULTS: Treatment with IFN-based new DAAs when fibrosis stage ⩾F2 is cost-effective compared to TVR/BOC-based triple therapy (euro37,900/QALY gained), but not at F0-1 (euro103,500/QALY gained). Awaiting the IFN-free regimens is more effective, except in F4 patients, but not cost-effective compared to IFN-based new DAAs. If we decrease the cost of IFN-free regimens close to that of IFN-based new DAAs, then awaiting the IFN-free regimen becomes cost-effective. CONCLUSIONS: Treatment with IFN-based new DAAs at stage ⩾F2 is both effective and cost-effective compared to TVR/BOC triple therapy. Awaiting IFN-free regimens and then treating regardless of fibrosis is more efficacious, except in F4 patients; however, the cost-effectiveness of this strategy is highly dependent on its cost.

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition.

Loss of phenotypic plasticity generates genotype-caste association in harvester ants.

Caste differentiation and reproductive division of labor are the hallmarks of insect societies. In ants and other social Hymenoptera, development of female larvae into queens or workers generally results from environmentally induced differences in gene expression. However, several cases in which certain gene combinations may determine reproductive status have been described in bees and ants. We investigated experimentally whether genotype directly influences caste determination in two populations of Pogonomyrmex harvester ants in which genotype-caste associations have been observed. Each population contains two genetic lineages. Queens are polyandrous and mate with males of both lineages , but in mature colonies, over 95% of daughter queens have a pure-lineage genome, whereas all workers are of F1 interlineage ancestry. We found that this pattern is maintained throughout the colony life cycle, even when only a single caste is being produced. Through controlled crosses, we demonstrate that pure-lineage eggs fail to develop into workers even when interlineage brood are not present. Thus, environmental caste determination in these individuals appears to have been lost in favor of a hardwired genetic mechanism. Our results reveal that genetic control of reproductive fate can persist without loss of the eusocial caste structure.

Monitoring of NY-ESO-1 specific CD4+ T cells using molecularly defined MHC class II/His-tag-peptide tetramers.

MHC-peptide tetramers have become essential tools for T-cell analysis, but few MHC class II tetramers incorporating peptides from human tumor and self-antigens have been developed. Among limiting factors are the high polymorphism of class II molecules and the low binding capacity of the peptides. Here, we report the generation of molecularly defined tetramers using His-tagged peptides and isolation of folded MHC/peptide monomers by affinity purification. Using this strategy we generated tetramers of DR52b (DRB3*0202), an allele expressed by approximately half of Caucasians, incorporating an epitope from the tumor antigen NY-ESO-1. Molecularly defined tetramers avidly and stably bound to specific CD4(+) T cells with negligible background on nonspecific cells. Using molecularly defined DR52b/NY-ESO-1 tetramers, we could demonstrate that in DR52b(+) cancer patients immunized with a recombinant NY-ESO-1 vaccine, vaccine-induced tetramer-positive cells represent ex vivo in average 1:5,000 circulating CD4(+) T cells, include central and transitional memory polyfunctional populations, and do not include CD4(+)CD25(+)CD127(-) regulatory T cells. This approach may significantly accelerate the development of reliable MHC class II tetramers to monitor immune responses to tumor and self-antigens.

Cytochrome P450 2D6 genotype and methadone steady-state concentrations

A genetic polymorphism of cytochrome P450 2D6 has been described with the existence of poor (zero functional genes), extensive (one or two functional genes), and ultrarapid metabolizers (three or more functional genes). The authors measured the steady-state trough (R)- (i.e., the active enantiomer), (S)-, and (R,S)-methadone plasma levels in opiate-dependent patients receiving methadone maintenance treatment (MMT) and genotyped them for cytochrome P4502D6. The patients' medical records were reviewed to assess the outcome of the MMT with regard to the absence of illicit opiate consumption and to the absence of withdrawal complaints in ultrarapid and poor metabolizers. Of 256 patients included, 18 were found to be poor metabolizers, 228 to be extensive metabolizers, and 10 to be ultrarapid metabolizers. Significant differences were found between genotypes for (R)- (p = 0.024), (S)- (p = 0.033), and (R,S)-methadone (p = 0.026) concentrations to dose-to-weight ratios. For (R)-methadone, a significant difference was found between ultrarapid metabolizers and poor metabolizers (p = 0.009), with the median value in the former group being only 54% of the median value in the latter group. These results confirm the involvement of cytochrome P450 2D6 in methadone metabolism. Although the difference was nonsignificant (p = 0.103), 13 (72%) of the 18 poor metabolizers and only 4 (40%) of the 10 ultrarapid metabolizers were considered successful in their treatment. More studies are needed to examine the influence of the ultrarapid metabolizer status on the outcome of the MMT.