255 research outputs found
The Rise of the Ethical License
The Broad Institute's recent licensing of its gene editing patent portfolio demonstrates how licenses can be used to restrict controversial applications of emerging technologies while society deliberates their implications.Ope
Restitution of superoxide generation in autosomal cytochrome-negative chronic granulomatous disease (A22(0) CGD)-derived B lymphocyte cell lines by transfection with p22phax cDNA
The respiratory burst oxidase of phagocytes and B lymphocytes is a multicomponent enzyme that catalyzes the one-electron reduction of oxygen by NADPH. It is responsible for the O2-production that occurs when these cells are exposed to phorbol 12-myristate 13-acetate or physiologic stimuli, such as phagocytosis in phagocytes or cross- linking of surface immunoglobulin in B lymphocytes. The activity of this enzyme is greatly diminished or absent in patients with chronic granulomatous disease (CGD), an inherited disorder characterized by a severe defect in host defense against bacteria and fungi. In every CGD patient studied so far, an abnormality has been found in a gene encoding one of the four components of the respiratory burst oxidase: the membrane proteins p22phox or gp91phox which together form the cytochrome b558 protein, or the cytosolic proteins p47phox or p67phox. Autosomal recessive cytochrome-negative CGD (A22(0) CGD) is associated with mutations in the gene coding for p22phox. We report here that the capacity for O2- production and cytochrome b558 protein expression were restored to Epstein-Barr virus-transformed B lymphocytes from two A22(0) CGD patients by transfection with an expression plasmid containing a p22phox cDNA. No detectable O2- was generated by untransfected p22phox-deficient lymphocytes. The genetic reconstitution of the respiratory burst in A22(0) CGD B lymphocytes by transfer of the wild-type p22phox cDNA represents a further step towards somatic gene therapy for this subgroup of A22(0) CGD. This system will also be useful for expression of genetically engineered mutant p22phox proteins in intact cells, facilitating the structure-function analysis of cytochrome b558
The Marker State Space (MSS) Method for Classifying Clinical Samples
The development of accurate clinical biomarkers has been challenging in part due to the diversity between patients and diseases. One approach to account for the diversity is to use multiple markers to classify patients, based on the concept that each individual marker contributes information from its respective subclass of patients. Here we present a new strategy for developing biomarker panels that accounts for completely distinct patient subclasses. Marker State Space (MSS) defines "marker states" based on all possible patterns of high and low values among a panel of markers. Each marker state is defined as either a case state or a control state, and a sample is classified as case or control based on the state it occupies. MSS was used to define multi-marker panels that were robust in cross validation and training-set/test-set analyses and that yielded similar classification accuracy to several other classification algorithms. A three-marker panel for discriminating pancreatic cancer patients from control subjects revealed subclasses of patients based on distinct marker states. MSS provides a straightforward approach for modeling highly divergent subclasses of patients, which may be adaptable for diverse applications. © 2013 Fallon et al
Chronic Granulomatous Disease; fundamental stages in our understanding of CGD
It has been 50 years since chronic granulomatous disease was first reported as a disease which fatally affected the ability of children to survive infections. Various milestone discoveries from the insufficient ability of patients' leucocytes to destroy microbial particles to the underlying genetic predispositions through which the disease is inherited have had important consequences. Longterm antibiotic prophylaxis has helped to fight infections associated with chronic granulomatous disease while the steady progress in bone marrow transplantation and the prospect of gene therapy are hailed as long awaited permanent treatment options. This review unearths the important findings by scientists that have led to our current understanding of the disease
Unsaturated long-chain fatty acids induce the respiratory burst of human neutrophils and monocytes in whole blood
Reactive oxygen species in phagocytic leukocytes
Phagocytic leukocytes consume oxygen and generate reactive oxygen species in response to appropriate stimuli. The phagocyte NADPH oxidase, a multiprotein complex, existing in the dissociated state in resting cells becomes assembled into the functional oxidase complex upon stimulation and then generates superoxide anions. Biochemical aspects of the NADPH oxidase are briefly discussed in this review; however, the major focus relates to the contributions of various modes of microscopy to our understanding of the NADPH oxidase and the cell biology of phagocytic leukocytes
Relevance of laboratory testing for the diagnosis of primary immunodeficiencies: a review of case-based examples of selected immunodeficiencies
The field of primary immunodeficiencies (PIDs) is one of several in the area of clinical immunology that has not been static, but rather has shown exponential growth due to enhanced physician, scientist and patient education and awareness, leading to identification of new diseases, new molecular diagnoses of existing clinical phenotypes, broadening of the spectrum of clinical and phenotypic presentations associated with a single or related gene defects, increased bioinformatics resources, and utilization of advanced diagnostic technology and methodology for disease diagnosis and management resulting in improved outcomes and survival. There are currently over 200 PIDs with at least 170 associated genetic defects identified, with several of these being reported in recent years. The enormous clinical and immunological heterogeneity in the PIDs makes diagnosis challenging, but there is no doubt that early and accurate diagnosis facilitates prompt intervention leading to decreased morbidity and mortality. Diagnosis of PIDs often requires correlation of data obtained from clinical and radiological findings with laboratory immunological analyses and genetic testing. The field of laboratory diagnostic immunology is also rapidly burgeoning, both in terms of novel technologies and applications, and knowledge of human immunology. Over the years, the classification of PIDs has been primarily based on the immunological defect(s) ("immunophenotype") with the relatively recent addition of genotype, though there are clinical classifications as well. There can be substantial overlap in terms of the broad immunophenotype and clinical features between PIDs, and therefore, it is relevant to refine, at a cellular and molecular level, unique immunological defects that allow for a specific and accurate diagnosis. The diagnostic testing armamentarium for PID includes flow cytometry - phenotyping and functional, cellular and molecular assays, protein analysis, and mutation identification by gene sequencing. The complexity and diversity of the laboratory diagnosis of PIDs necessitates many of the above-mentioned tests being performed in highly specialized reference laboratories. Despite these restrictions, there remains an urgent need for improved standardization and optimization of phenotypic and functional flow cytometry and protein-specific assays. A key component in the interpretation of immunological assays is the comparison of patient data to that obtained in a statistically-robust manner from age and gender-matched healthy donors. This review highlights a few of the laboratory assays available for the diagnostic work-up of broad categories of PIDs, based on immunophenotyping, followed by examples of disease-specific testing
Action of the 4-Nitro-2-phenoximethanesulphonanilide (Nimesulide) on neutrophil chemotaxis and superoxide production
Superoxide production by phagocytic leukocytes: the scientific legacy of Bernard Babior
It was 32 years ago that Bernard Babior, Ruby Kipnes, and I submitted a paper to the JCI reporting that polymorphonuclear leukocytes produce superoxide (O(2)(–)) during phagocytosis and that this highly reactive oxygen radical might function as a microbicidal agent. The story of how our lab came to this discovery is one of a special relationship between a student and his brilliant mentor
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