Mutations in GFAP, encoding glial fibrillary acidic protein, are associated with Alexander disease

Alexander disease is a rare disorder of the central nervous system of unknown etiology. Infants with Alexander disease develop a leukoencephalopathy with macrocephaly, seizures and psychomotor retardation, leading to death usually within the first decade; patients with juvenile or adult forms typically experience ataxia, bulbar signs and spasticity, and a more slowly progressive course. The pathological hallmark of all forms of Alexander disease is the presence of Rosenthal fibers, cytoplasmic inclusions in astrocytes that contain the intermediate filament protein GFAP in association with small heat-shock proteins. We previously found that overexpression of human GFAP in astrocytes of transgenic mice is fatal and accompanied by the presence of inclusion bodies indistinguishable from human Rosenthal fibers. These results suggested that a primary alteration in GFAP may be responsible for Alexander disease. Sequence analysis of DNA samples from patients representing different Alexander disease phenotypes revealed that most cases are associated with non-conservative mutations in the coding region of GFAP. Alexander disease therefore represents the first example of a primary genetic disorder of astrocytes, one of the major cell types in the vertebrate CNS.

Proteolytic exposure of a cryptic site within collagen type IV is required for angiogenesis and tumor growth in vivo

Evidence is provided that proteolytic cleavage of collagen type IV results in the exposure of a functionally important cryptic site hidden within its triple helical structure. Exposure of this cryptic site was associated with angiogenic, but not quiescent, blood vessels and was required for angiogenesis in vivo. Exposure of the HUIV26 epitope was associated with a loss of alpha1beta1 integrin binding and the gain of alphavbeta3 binding. A monoclonal antibody (HUIV26) directed to this site disrupts integrin-dependent endothelial cell interactions and potently inhibits angiogenesis and tumor growth. Together, these studies suggest a novel mechanism by which proteolysis contributes to angiogenesis by exposing hidden regulatory elements within matrix-immobilized collagen type IV.

Quantification of antigen specific CD8+ T cells using an ELISPOT assay

An ELISPOT assay to detect and determine the number of antigen specific CD8+ T cells was standardized using cloned murine CD8+ T cells specific for the epitope SYVPSAEQI of a rodent malaria antigen. This assay is based on the detection of IFN-gamma secretion by single cells after their stimulation with antigen. The interferon secretion is visualized as spots revealed by using enzyme labeled anti-IFN-gamma monoclonal antibodies. Using known numbers of cloned murine CD8+ T cells it was determined that the assay detects 80-95% of these CD8+ T cells. The optimal culture conditions for the stimulation of the CD8+ T cells were determined and the antigen concentration, number of antigen presenting cells and supplement of growth factors required to perform the assay were defined. This ELISPOT assay can be performed with spleen cells from immunized mice, and provide the precise number of antigen specific CD8+ T cells present in mixed lymphocyte populations. This method is more sensitive than the chromium-51 release assay, and much simpler than the conventional precursor frequency analysis, providing the number of antigen specific CD8+ T cells in 36-48 h.

Neurodegeneration associated with genetic defects in phospholipase A(2)

OBJECTIVE

Mutations in the gene encoding phospholipase A(2) group VI (PLA2G6) are associated with two childhood neurologic disorders: infantile neuroaxonal dystrophy (INAD) and idiopathic neurodegeneration with brain iron accumulation (NBIA). INAD is a severe progressive psychomotor disorder in which axonal spheroids are found in brain, spinal cord, and peripheral nerves. High globus pallidus iron is an inconsistent feature of INAD; however, it is a diagnostic criterion of NBIA, which describes a clinically and genetically heterogeneous group of disorders that share this hallmark feature. We sought to delineate the clinical, radiographic, pathologic, and genetic features of disease resulting from defective phospholipase A(2).

METHODS

We identified 56 patients clinically diagnosed with INAD and 23 with idiopathic NBIA and screened their DNA for PLA2G6 mutations.

RESULTS

Eighty percent of patients with INAD had mutations in PLA2G6, whereas mutations were found in only 20% of those with idiopathic NBIA. All patients with two null mutations had a more severe phenotype. On MRI, nearly all mutation-positive patients had cerebellar atrophy, and half showed brain iron accumulation. We observed Lewy bodies and neurofibrillary tangles in association with PLA2G6 mutations.

CONCLUSION

Defects in phospholipase A(2) lead to a range of phenotypes. PLA2G6 mutations are associated with nearly all cases of classic infantile neuroaxonal dystrophy but a minority of cases of idiopathic neurodegeneration with brain iron accumulation, and genotype correlates with phenotype. Cerebellar atrophy predicts which patients are likely to be mutation-positive. The neuropathologic changes that are caused by defective phospholipase A(2) suggest a shared pathogenesis with both Parkinson and Alzheimer diseases.

Priming with recombinant influenza virus followed by administration of recombinant vaccinia virus induces CD8+ T-cell-mediated protective immunity against malaria

Live vectors expressing foreign antigens have been used to induce immunity against several pathogens. However, for the virulent rodent malaria parasite Plasmodium yoelii, the use of recombinant vaccinia virus, pseudorabies virus, or Salmonella, expressing the circumsporozoite protein of this parasite, failed to induce protection. We generated a recombinant influenza virus expressing an epitope from the circumsporozoite protein of P. yoelii known to be recognized by CD8+ T cells and demonstrated that this vector induced class I major histocompatibility complex-restricted cytotoxic T cells against this foreign epitope. Immunization of mice with this recombinant influenza virus, followed by a recombinant vaccinia virus expressing the entire circumsporozoite protein, induced protective immunity against sporozoite-induced malaria. The sequence of immunization appears to be crucial, since a primer injection with recombinant vaccinia virus, followed by a booster injection with recombinant influenza virus, failed to induce protection. The protection induced by immunization with these recombinant viruses is mostly mediated by CD8+ T cells, as treatment of mice with anti-CD8 monoclonal antibody abolishes the anti-malarial immunity. The use of different live vectors for primer and booster injections has a synergistic effect on the immune response and might represent an effective general strategy for eliciting protective immune responses to key antigens of microbial pathogens.

Phenotype at diagnosis predicts recurrence rates in Crohn's disease

BACKGROUND

In Crohn's disease (CD), studies associating phenotype at diagnosis and subsequent disease activity are important for patient counselling and health care planning.

AIMS

To calculate disease recurrence rates and to correlate these with phenotypic traits at diagnosis.

METHODS

A prospectively assembled uniformly diagnosed European population based inception cohort of CD patients was classified according to the Vienna classification for disease phenotype at diagnosis. Surgical and non-surgical recurrence rates throughout a 10 year follow up period were calculated. Multivariate analysis was performed to classify risk factors present at diagnosis for recurrent disease.

RESULTS

A total of 358 were classified for phenotype at diagnosis, of whom 262 (73.2%) had a first recurrence and 113 patients (31.6%) a first surgical recurrence during the first 10 years after diagnosis. Patients with upper gastrointestinal disease at diagnosis had an excess risk of recurrence (hazard ratio 1.54 (95% confidence interval (CI) 1.13-2.10)) whereas age >/=40 years at diagnosis was protective (hazard ratio 0.82 (95% CI 0.70-0.97)). Colonic disease was a protective characteristic for resective surgery (hazard ratio 0.38 (95% CI 0.21-0.69)). More frequent resective surgical recurrences were reported from Copenhagen (hazard ratio 3.23 (95% CI 1.32-7.89)).

CONCLUSIONS

A mild course of disease in terms of disease recurrence was observed in this European cohort. Phenotype at diagnosis had predictive value for disease recurrence with upper gastrointestinal disease being the most important positive predictor. A phenotypic North-South gradient in CD may be present, illustrated by higher surgery risks in some of the Northern European centres.

Neuromyelitis optica in France: a multicenter study of 125 patients

BACKGROUND

There have been few epidemiologic studies on neuromyelitis optica (NMO) and none used the recent 2006 diagnostic criteria. Here we describe the clinical, laboratory, MRI, and disability course of NMO in a French cohort of 125 patients.

METHODS

We performed an observational, retrospective, multicenter study. Data were collected from September 2007 through August 2008, corresponding to the endpoint of the study. We identified 125 patients fulfilling the 2006 NMO criteria. Selection was made using hospital files and a specific clinical questionnaire for NMO.

RESULTS

Mean age at onset was 34.5 years (range 4-66) with a mean disease duration of 10 +/- 7.8 years at the endpoint. The patients were mainly (87%) Caucasian, with a female:male ratio of 3:1. In 90% of cases, the association of optic neuritis, longitudinal extensive myelitis, and a Paty-negative initial brain MRI was sufficient to fulfill the supportive criteria. Eighty-eight percent of patients were treated with immunosuppressive therapies. Median delay from onset to Expanded Disability Status Scale (EDSS) score 4 was 7 years; score 6, 10 years; and score 7, 21 years. The first episode of myelitis was immediately followed by an EDSS score > or = 4 in 37.3% of cases, and a severe residual visual loss was observed in 22% of patients after the first episode of optic neuritis. Multivariate analysis did not reveal any predictors of a poor evolution other than a high number of MRI brain lesions at diagnosis, which were predictive of a residual visual acuity < or = 1/10.

CONCLUSIONS

Our demographic data provide new data on disability in patients with neuromyelitis optica, most of whom were receiving treatment.

Radiation-induced cerebral vasculopathy in children with neurofibromatosis and optic pathway glioma

Occlusive vasculopathy is a potential complication of radiotherapy in children with optic pathway glioma. With a median follow-up of 7 years, 13 of 69 children in this study developed clinical and radiological signs of occlusive vasculopathy after radiotherapy within a median interval of 36 months. The major risk factor was neurofibromatosis type 1. Radiotherapy should no longer be the first treatment in these settings. When radiotherapy is unavoidable, regular screening for cerebral vasculopathy is mandatory, as preventive treatment is available.

Plastid-expressed 5-enolpyruvylshikimate-3-phosphate synthase genes provide high level glyphosate tolerance in tobacco

Plastid transformation (transplastomic) technology has several potential advantages for biotechnological applications including the use of unmodified prokaryotic genes for engineering, potential high-level gene expression and gene containment due to maternal inheritance in most crop plants. However, the efficacy of a plastid-encoded trait may change depending on plastid number and tissue type. We report a feasibility study in tobacco plastids to achieve high-level herbicide resistance in both vegetative tissues and reproductive organs. We chose to test glyphosate resistance via over-expression in plastids of tolerant forms of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). Immunological, enzymatic and whole-plant assays were used to prove the efficacy of three different prokaryotic (Achromobacter, Agrobacterium and Bacillus) EPSPS genes. Using the Agrobacterium strain CP4 EPSPS as a model we identified translational control sequences that direct a 10,000-fold range of protein accumulation (to >10% total soluble protein in leaves). Plastid-expressed EPSPS could provide very high levels of glyphosate resistance, although levels of resistance in vegetative and reproductive tissues differed depending on EPSPS accumulation levels, and correlated to the plastid abundance in these tissues. Paradoxically, higher levels of plastid-expressed EPSPS protein accumulation were apparently required for efficacy than from a similar nuclear-encoded gene. Nevertheless, the demonstration of high-level glyphosate tolerance in vegetative and reproductive organs using transplastomic technology provides a necessary step for transfer of this technology to other crop species.

The effect of genotype on the natural history of eIF2B-related leukodystrophies

BACKGROUND

Recessive mutations in the five eucaryotic initiation factor 2B (eIF2B) subunits have been found in leukodystrophies of variable age at onset and severity.

OBJECTIVES

To evaluate the clinical spectrum of eIF2B-related disorders and search for a phenotype-genotype correlation.

METHODS

Ninety-three individuals (78 families) with an undetermined leukodystrophy were selected on MRI-based criteria of childhood ataxia with central hypomyelination/vanishing white matter (CACH/VWM) for EIF2B genes analysis.

RESULTS

Eighty-nine percent of individuals with MRI criteria of CACH/VWM have a mutation in one of the eIF2B beta to epsilon subunits. For 83 individuals (68 families), 46 distinct mutations (90% missense) in four of the five eIF2B subunits (beta, gamma, delta, epsilon) were identified. Sixty-four percent were in the epsilon subunit, a R113H substitution was found in 71% of eIF2B epsilon-mutated families. A large clinical spectrum was observed from rapidly fatal infantile to asymptomatic adult forms. Disease severity was correlated with age at onset (p < 0.0001) but not with the type of the mutated subunit nor with the position of the mutation within the protein. Mutations R113H in the epsilon subunit and E213G in the beta subunit were significantly associated with milder forms.

CONCLUSIONS

The degree of eIF2B dysfunction, which is involved in the regulation of protein synthesis during cellular stress, may play a role in the clinical expression of eIF2B-related disorders.

Performance of the ATLAS trigger system in 2015

During 2015 the ATLAS experiment recorded [Formula: see text] of proton-proton collision data at a centre-of-mass energy of [Formula: see text]. The ATLAS trigger system is a crucial component of the experiment, responsible for selecting events of interest at a recording rate of approximately 1 kHz from up to 40 MHz of collisions. This paper presents a short overview of the changes to the trigger and data acquisition systems during the first long shutdown of the LHC and shows the performance of the trigger system and its components based on the 2015 proton-proton collision data.

Prevalence and susceptibility profile of Candida metapsilosis and Candida orthopsilosis: results from population-based surveillance of candidemia in Spain

We describe the prevalences and susceptibility profiles of two recently described species, Candida metapsilosis and Candida orthopsilosis, related to Candida parapsilosis in candidemia. The prevalences of these species (1.7% for C. metapsilosis and 1.4% for C. orthopsilosis) are significant. Differences observed in their susceptibility profiles could have therapeutic importance.

Suppression of asthma-like responses in different mouse strains by oral tolerance

In this study we examined the effect of oral antigen (Ag) administration on the development of experimental asthma in different mouse strains. We selected BALB/c, BP2, CBA/Ca interleukin (IL)-5 transgenic, and BALB/c T-cell receptor-delta-deficient mouse strains because they exhibit different aspects of the asthma syndrome. Mice exposed to 1% ovalbumin (OVA), dissolved in the drinking water for 5 consecutive days, became unresponsive to subsequent immunogenic OVA challenges. This regimen of OVA administration induced Ag-specific unresponsiveness in all mouse strains tested, including gammadelta-deficient mice that are said to be resistant to tolerance induction. The Ag-specific unresponsiveness was characterized by reduced (almost absent) airway eosinophilic inflammation, airway hyperreactivity, and mucus production; also by low levels of T helper (Th) 2-type cytokines in bronchoalveolar lavage fluid, and decreased immunoglobulin (Ig) G1 and IgE OVA-specific antibody production. The unresponsive state was not associated with increased levels of the suppressive cytokines IL-10 and transforming growth factor (TGF)-beta or with immune deviation toward the Th1 pathway due to increased levels of interferon-gamma and IL-12. Moreover, treatment with anti- TGF-beta antibodies did not abrogate oral tolerance. Oral Ag administration was quite effective in suppressing the development of key features of asthma when initiated after primary immunization (Day 0) or after booster (Day 7), but not after challenge (Day 14) when it increased allergic responses. Collectively, our findings show for the first time the beneficial and detrimental effects of oral Ag administration on the development of experimental asthma.

When do children with optic pathway tumours need treatment? An oncological perspective in 106 patients treated in a single centre

Progression patterns of optic pathway tumours (OPT) need to be precisely defined for treatment planning. In patients with neurofibromatosis type 1 (NF1), this disease is usually indolent and the available literature rarely reports progression after the age of 6 years. In patients without NF1, the disease course seems to be less favourable. We reviewed the clinical and radiological files of 106 children referred to our institution for the treatment of a symptomatic OPT since 1980. NF1 was present in 51 of them. Progression patterns in children with NF1 differed markedly from those in the other patients. A total of 83 children had tumour extension beyond the chiasm (Dodge type III). Children with NF1 had progressive tumours later during follow-up (47% after the age of 6 years), had more often proptosis and infiltrating tumours but less frequently nystagmus or increased intracranial pressure. 32 children were not treated at diagnosis because they had only mild symptoms related to the OPT. In these patients, progression occurred more often in children without than with NF1 (12/12 versus 12/20 respectively, P = 0.04). A high number of patients needed treatment for progression or severe symptoms after 6 years of age. Of the patients, 33% needed treatment for progression or severe symptoms after 6 years of age.

CONCLUSION

Progression patterns of optic pathway tumours in children with neurofibromatosis type 1 differ markedly from those in other patients. This study emphasises the need for prolonged follow-up of children with optic pathway tumours, especially in neurofibromatosis type 1.

Infantile Alexander disease: spectrum of GFAP mutations and genotype-phenotype correlation

Heterozygous, de novo mutations in the glial fibrillary acidic protein (GFAP) gene have recently been reported in 12 patients affected by neuropathologically proved Alexander disease. We searched for GFAP mutations in a series of patients who had heterogeneous clinical symptoms but were candidates for Alexander disease on the basis of suggestive neuroimaging abnormalities. Missense, heterozygous, de novo GFAP mutations were found in exons 1 or 4 for 14 of the 15 patients analyzed, including patients without macrocephaly. Nine patients carried arginine mutations (four had R79H; four had R239C; and one had R239H) that have been described elsewhere, whereas the other five had one of four novel mutations, of which two affect arginine (2R88C and 1R88S) and two affect nonarginine residues (1L76F and 1N77Y). All mutations were located in the rod domain of GFAP, and there is a correlation between clinical severity and the affected amino acid. These results confirm that GFAP mutations are a reliable molecular marker for the diagnosis of infantile Alexander disease, and they also form a basis for the recommendation of GFAP analysis for prenatal diagnosis to detect potential cases of germinal mosaicism.

Expression of the firefly luciferase gene in vaccinia virus: a highly sensitive gene marker to follow virus dissemination in tissues of infected animals

We have introduced the firefly luciferase gene of Photinus pyralis into the vaccinia virus genome. This gene is expressed in a coordinate fashion during virus infection. Luminescence produced by the action of luciferase [Photinus-luciferin:oxygen 4-oxidoreductase(decarboxylating, ATP-hydrolyzing), EC 1.13.12.7] was easily detectable in infected cells in culture as well as in cells of tissues of infected mice. The limits of detection were about one infected cell in a background of a million noninfected cells. The luciferase assay was about 1000-fold more sensitive than that of beta-galactosidase. Our findings show that the luciferase assay can be conveniently used to follow viral gene expression and virus dissemination both in cell cultures and in tissues of infected animals.

Characterization of in vivo primary and secondary CD8+ T cell responses induced by recombinant influenza and vaccinia viruses

We characterized the in vivo primary and secondary murine CD8+ T cell responses induced by immunization with influenza and vaccinia viruses, which were engineered to express the same H-2K(k)- and H-2K(d)-restricted epitopes. Our results show that the induction and magnitude of the primary CD8+ T cell response closely depends on the viral dose used for immunization, while it is not affected by the route of immunization. The induction of secondary CD8+ T cell responses appears to be highly restricted, as suggested by the lack of in vivo expansion of antigen-specific CD8+ T cells after repeated immunization with the same virus. In contrast, a 20- to 30-fold increase in the frequency of antigen-specific CD8+ T cells could be induced after combined immunization with recombinant influenza and vaccinia viruses. These findings may provide the basis for the development of new prophylactic and therapeutic strategies to prevent or control intracellular infections and certain malignancies.

Recombinant vaccinia viruses expressing GP46/M-2 protect against Leishmania infection

Leishmania is a genus of parasitic protozoa capable of causing a spectrum of human diseases. The GP46/M-2 membrane glycoprotein has been demonstrated in a murine model system to elicit a protective immune response against infection with Leishmania amazonensis; in highly susceptible BALB/c mice, immunization leads to significant protection against infection. In the present study, for induction of long-term immunological effects, two recombinant vaccinia viruses, derived from the wild type and attenuated variant 48-7 and expressing the GP46/M-2 protein, were constructed; to ensure safety, we used the attenuated vaccinia virus mutant (48-7) as a live vector. Susceptible BALB/c mice immunized with either GP46/M-2-recombinant vaccinia virus were significantly protected against infection with L. amazonensis; 45 to 76% of the animals were completely protected (sterile) against a challenge inoculum of 10(3) infective organisms. The protectively immunized animals demonstrated T- and B-cell-dependent immunological responses; both lymphokine responses as well as antibody responses and long-term memory are indicative of T-cell activation. This first report of the use of a recombinant vaccinia virus to induce protection against a Leishmania infection indicates that recombinant vaccinia viruses should be of value in the design of a safe and effective vaccine against this parasitic disease.

Muon reconstruction performance of the ATLAS detector in proton-proton collision data at [Formula: see text]=13 TeV

This article documents the performance of the ATLAS muon identification and reconstruction using the LHC dataset recorded at [Formula: see text] TeV in 2015. Using a large sample of [Formula: see text] and [Formula: see text] decays from 3.2 fb[Formula: see text] of pp collision data, measurements of the reconstruction efficiency, as well as of the momentum scale and resolution, are presented and compared to Monte Carlo simulations. The reconstruction efficiency is measured to be close to [Formula: see text] over most of the covered phase space ([Formula: see text] and [Formula: see text] GeV). The isolation efficiency varies between 93 and [Formula: see text] depending on the selection applied and on the momentum of the muon. Both efficiencies are well reproduced in simulation. In the central region of the detector, the momentum resolution is measured to be [Formula: see text] ([Formula: see text]) for muons from [Formula: see text] ([Formula: see text]) decays, and the momentum scale is known with an uncertainty of [Formula: see text]. In the region [Formula: see text], the [Formula: see text] resolution for muons from [Formula: see text] decays is [Formula: see text] while the precision of the momentum scale for low-[Formula: see text] muons from [Formula: see text] decays is about [Formula: see text].