IgA Autoimmune Disorders: Development of a Passive Transfer Mouse Model

IgA is present in the skin in several dermatoses, including dermatitis herpetiformis, linear IgA bullous dermatosis, and Henoch-Schoenlein purpura. The neutrophilic infiltration in the area of the IgA deposition suggests that IgA is responsible for the associated inflammatory events. The mechanism for this process is unproven, but is likely to involve IgA-mediated neutrophil chemotaxis with inhibition of chemotaxis by dapsone. Elucidation of the mechanism of IgA-mediated inflammation will require an animal model. We have established a model for linear IgA bullous dermatosis as a prototype disease to be studied. IgA mouse monoclonal antibodies against a linear IgA bullous dermatosis antigen have been passively transferred to SCID mice with human skin grafts. This has produced neutrophil infiltration and basement membrane vesiculation in 4 of 12 mice tested. We conclude that an animal model for the pathogenesis of IgA dermatoses with IgA deposition and inflammation can be produced by passive transfer of mouse IgA antibodies against a linear IgA antigen

Argus: A 16-pixel Millimeter-Wave Spectrometer for the Green Bank Telescope

We report on the development of Argus, a 16-pixel spectrometer, which will enable fast astronomical imaging over the 85–116 GHz band. Each pixel includes a compact heterodyne receiver module, which integrates two InP MMIC low-noise amplifiers, a coupled-line bandpass filter and a sub-harmonic Schottky diode mixer. The receiver signals are routed to and from the multi-chip MMIC modules with multilayer high frequency printed circuit boards, which includes LO splitters and IF amplifiers. Microstrip lines on flexible circuitry are used to transport signals between temperature stages. The spectrometer frontend is designed to be scalable, so that the array design can be reconfigured for future instruments with hundreds of pixels. Argus is scheduled to be commissioned at the Robert C. Byrd Green Bank Telescope in late 2014. Preliminary data for the first Argus pixels are presented

High throughput mutagenesis for identification of residues regulating human prostacyclin (hIP) receptor

The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structurefunction relationship of GPCRs. © 2014 Bill et al

Phase 1 Study of Two Merozoite Surface Protein 1 (MSP1(42)) Vaccines for Plasmodium falciparum Malaria

OBJECTIVES: To assess the safety and immunogenicity of two vaccines, MSP1(42)-FVO/Alhydrogel and MSP1(42)-3D7/Alhydrogel, targeting blood-stage Plasmodium falciparum parasites. DESIGN: A Phase 1 open-label, dose-escalating study. SETTING: Quintiles Phase 1 Services, Lenexa, Kansas between July 2004 and November 2005. PARTICIPANTS: Sixty healthy malaria-naïve volunteers 18–48 y of age. INTERVENTIONS: The C-terminal 42-kDa region of merozoite surface protein 1 (MSP1(42)) corresponding to the two allelic forms present in FVO and 3D7 P. falciparum lines were expressed in Escherichia coli, refolded, purified, and formulated on Alhydrogel (aluminum hydroxide). For each vaccine, volunteers in each of three dose cohorts (5, 20, and 80 μg) were vaccinated at 0, 28, and 180 d. Volunteers were followed for 1 y. OUTCOME MEASURES: The safety of MSP1(42)-FVO/Alhydrogel and MSP1(42)-3D7/Alhydrogel was assessed. The antibody response to each vaccine was measured by reactivity to homologous and heterologous MSP1(42), MSP1(19), and MSP1(33) recombinant proteins and recognition of FVO and 3D7 parasites. RESULTS: Anti-MSP1(42) antibodies were detected by ELISA in 20/27 (74%) and 22/27 (81%) volunteers receiving three vaccinations of MSP1(42)-FVO/Alhydrogel or MSP1(42)-3D7/Alhydrogel, respectively. Regardless of the vaccine, the antibodies were cross-reactive to both MSP1(42)-FVO and MSP1(42)-3D7 proteins. The majority of the antibody response targeted the C-terminal 19-kDa domain of MSP1(42), although low-level antibodies to the N-terminal 33-kDa domain of MSP1(42) were also detected. Immunofluorescence microscopy of sera from the volunteers demonstrated reactivity with both FVO and 3D7 P. falciparum schizonts and free merozoites. Minimal in vitro growth inhibition of FVO or 3D7 parasites by purified IgG from the sera of the vaccinees was observed. CONCLUSIONS: The MSP1(42)/Alhydrogel vaccines were safe and well tolerated but not sufficiently immunogenic to generate a biologic effect in vitro. Addition of immunostimulants to the Alhydrogel formulation to elicit higher vaccine-induced responses in humans may be required for an effective vaccine

Cellular responses to modified Plasmodium falciparum MSP119 antigens in individuals previously exposed to natural malaria infection

<p>Abstract</p> <p>Background</p> <p>MSP1 processing-inhibitory antibodies bind to epitopes on the 19 kDa C-terminal region of the <it>Plasmodium falciparum </it>merozoite surface protein 1 (MSP1₁₉), inhibiting erythrocyte invasion. Blocking antibodies also bind to this antigen but prevent inhibitory antibodies binding, allowing invasion to proceed. Recombinant MSP1₁₉had been modified previously to allow inhibitory but not blocking antibodies to continue to bind. Immunization with these modified proteins, therefore, has the potential to induce more effective protective antibodies. However, it was unclear whether the modification of MSP1₁₉would affect critical T-cell responses to epitopes in this antigen.</p> <p>Methods</p> <p>The cellular responses to wild-type MSP1₁₉and a panel of modified MSP1₁₉antigens were measured using an <it>in-vitro </it>assay for two groups of individuals: the first were malaria-naïve and the second had been naturally exposed to <it>Plasmodium falciparum </it>infection. The cellular responses to the modified proteins were examined using cells from malaria-exposed infants and adults.</p> <p>Results</p> <p>Interestingly, stimulation indices (SI) for responses induced by some of the modified proteins were at least two-fold higher than those elicited by the wild-type MSP1₁₉. A protein with four amino acid substitutions (Glu27→Tyr, Leu31→Arg, Tyr34→Ser and Glu43→Leu) had the highest stimulation index (SI up to 360) and induced large responses in 64% of the samples that had significant cellular responses to the modified proteins.</p> <p>Conclusion</p> <p>This study suggests that specific MSP1₁₉variants that have been engineered to improve their antigenicity for inhibitory antibodies, retain T-cell epitopes and the ability to induce cellular responses. These proteins are candidates for the development of MSP1-based malaria vaccines.</p

A microscopy-based screen employing multiplex genome sequencing identifies cargo-specific requirements for dynein velocity

The timely delivery of membranous organelles and macromolecules to specific locations within the majority of eukaryotic cells depends on microtubule-based transport. Here, we describe a screening method to identify mutations that have a critical effect on intracellular transport and its regulation using mutagenesis, multicolor-fluorescence microscopy, and multiplex genome sequencing. This screen exploits the filamentous fungus Aspergillus nidulans, which has many of the advantages of yeast molecular genetics, but uses long-range microtubule-based transport in a manner more similar to metazoan cells. Using this method, we identified 7 mutants that represent novel alleles of components of the intracellular transport machinery: specifically, kinesin-1, cytoplasmic dynein, and the dynein regulators Lis1 and dynactin. The two dynein mutations identified in our screen map to dynein's AAA+ catalytic core. Single-molecule studies reveal that both mutations reduce dynein's velocity in vitro. In vivo these mutants severely impair the distribution and velocity of endosomes, a known dynein cargo. In contrast, another dynein cargo, the nucleus, is positioned normally in these mutants. These results reveal that different dynein functions have distinct velocity requirements

Associations with photoreceptor thickness measures in the UK Biobank.

Spectral-domain OCT (SD-OCT) provides high resolution images enabling identification of individual retinal layers. We included 32,923 participants aged 40-69 years old from UK Biobank. Questionnaires, physical examination, and eye examination including SD-OCT imaging were performed. SD OCT measured photoreceptor layer thickness includes photoreceptor layer thickness: inner nuclear layer-retinal pigment epithelium (INL-RPE) and the specific sublayers of the photoreceptor: inner nuclear layer-external limiting membrane (INL-ELM); external limiting membrane-inner segment outer segment (ELM-ISOS); and inner segment outer segment-retinal pigment epithelium (ISOS-RPE). In multivariate regression models, the total average INL-RPE was observed to be thinner in older aged, females, Black ethnicity, smokers, participants with higher systolic blood pressure, more negative refractive error, lower IOPcc and lower corneal hysteresis. The overall INL-ELM, ELM-ISOS and ISOS-RPE thickness was significantly associated with sex and race. Total average of INL-ELM thickness was additionally associated with age and refractive error, while ELM-ISOS was additionally associated with age, smoking status, SBP and refractive error; and ISOS-RPE was additionally associated with smoking status, IOPcc and corneal hysteresis. Hence, we found novel associations of ethnicity, smoking, systolic blood pressure, refraction, IOPcc and corneal hysteresis with photoreceptor thickness

Whose personal is more political? Experience in contemporary feminist politics

Whose personal is more political? This paper rethinks the role of experience in contemporary feminism, arguing that it can operate as a form of capital within abstracted and decontextualised debates which entrench existing power relations. Although experiential epistemologies are crucial to progressive feminist thought and action, in a neoliberal context in which the personal and emotional is commodified powerful groups can mobilise traumatic narratives to gain political advantage. Through case study analysis this paper shows how privileged feminists, speaking for others and sometimes for themselves, use experience to generate emotion and justify particular agendas, silencing critics who are often from more marginalised social positions. The use of the experiential as capital both reflects and perpetuates the neoliberal invisibilisation of structural dynamics: it situates all experiences as equal, and in the process fortifies existing inequalities. This competitive discursive field is polarising, and creates selective empathies through which we tend to discredit others¹ realities instead of engaging with their politics. However, I am not arguing for a renunciation of the politics of experience: instead, I ask that we resist its commodification and respect varied narratives while situating them in a structural frame

Perceptions of hypertension treatment among patients with and without diabetes

<p>Abstract</p> <p>Background</p> <p>Despite the availability of a wide selection of effective antihypertensive treatments and the existence of clear treatment guidelines, many patients with hypertension do not have controlled blood pressure. We conducted a qualitative study to explore beliefs and perceptions regarding hypertension and gain an understanding of barriers to treatment among patients with and without diabetes.</p> <p>Methods</p> <p>Ten focus groups were held for patients with hypertension in three age ranges, with and without diabetes. The topic guides for the groups were: What will determine your future health status? What do you understand by "raised blood pressure"? How should one go about treating raised blood pressure?</p> <p>Results</p> <p>People with hypertension tend to see hypertension not as a disease but as a risk factor for myocardial infarction or stroke. They do not view it as a continuous, degenerative process of damage to the vascular system, but rather as a binary risk process, within which you can either be a winner (not become ill) or a loser. This makes non-adherence to treatment a gamble with a potential positive outcome. Patients with diabetes are more likely to accept hypertension as a chronic illness with minor impact on their routine, and less important than their diabetes. Most participants overestimated the effect of stress as a causative factor believing that a reduction in levels of stress is the most important treatment modality. Many believe they "know their bodies" and are able to control their blood pressure. Patients without diabetes were most likely to adopt a treatment which is a compromise between their physician's suggestions and their own understanding of hypertension.</p> <p>Conclusion</p> <p>Patient denial and non-adherence to hypertension treatment is a prevalent phenomenon reflecting a conscious choice made by the patient, based on his knowledge and perceptions regarding the medical condition and its treatment. There is a need to change perception of hypertension from a gamble to a disease process. Changing the message from the existing one of "silent killer" to one that depicts hypertension as a manageable disease process may have the potential to significantly increase adherence rates.</p