Generation of Human Antigen-Specific Monoclonal IgM Antibodies Using Vaccinated “Human Immune System” Mice

Passive transfer of antibodies not only provides immediate short-term protection against disease, but also can be exploited as a therapeutic tool. However, the 'humanization' of murine monoclonal antibodies (mAbs) is a time-consuming and expensive process that has the inherent drawback of potentially altering antigenic specificity and/or affinity. The immortalization of human B cells represents an alternative for obtaining human mAbs, but relies on the availability of biological samples from vaccinated individuals or convalescent patients. In this work we describe a novel approach to generate fully human mAbs by combining a humanized mouse model with a new B cell immortalization technique. After transplantation with CD34+CD38⁻ human hematopoietic progenitor cells, BALB/c Rag2⁻/⁻IL-2Rγc⁻/⁻ mice acquire a human immune system and harbor B cells with a diverse IgM repertoire. "Human Immune System" mice were then immunized with two commercial vaccine antigens, tetanus toxoid and hepatitis B surface antigen. Sorted human CD19+CD27+ B cells were retrovirally transduced with the human B cell lymphoma (BCL)-6 and BCL-XL genes, and subsequently cultured in the presence of CD40-ligand and IL-21. This procedure allows generating stable B cell receptor-positive B cells that secrete immunoglobulins. We recovered stable B cell clones that produced IgM specific for tetanus toxoid and the hepatitis B surface antigen, respectively. This work provides the proof-of-concept for the usefulness of this novel method based on the immunization of humanized mice for the rapid generation of human mAbs against a wide range of antigen

CSR and related terms in SME owner-managers' mental models in six European countries: national context matters

As a contribution to the emerging field of corporate social responsibility (CSR) cognition, this article reports on the findings of an exploratory study that compares SME owner–managers’ mental models with regard to CSR and related concepts across six European countries (Belgium, Italy, Norway, France, UK, Spain). Utilising Repertory Grid Technique, we found that the SME owner–managers’ mental models show a few commonalities as well as a number of differences across the different country samples. We interpret those differences by linking individual cognition to macro-environmental variables, such as language, national traditions and dissemination mechanisms. The results of our exploratory study show that nationality matters but that classifications of countries as found in the comparative capitalism literature do not exactly mirror national differences in CSR cognition and that these classifications need further differentiation. The findings from our study raise questions on the universality of cognition of academic management concepts and warn that promotion of responsible business practice should not rely on the use of unmediated US American management terminology

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Maximal increase in sensitivity with minimal loss of specificity for diagnosis of acute coronary occlusion achieved by sequentially adding leads from the 24-lead electrocardiogram to the orderly sequenced 12-lead electrocardiogram

Objectives: This study investigates whether sequential addition of inverted, (negative) leads from the 24-lead electrocardiogram (ECG) to the orderly sequenced 12-lead ECG would identify a number of leads with which the sensitivity for diagnosis of acute transmural ischemia is significantly increased with minimal loss of specificity. Background: Acute transmural ischemia due to thrombotic coronary occlusion typically progresses to infarction. Its recognition is based on currently accepted ST-elevation myocardial infarction (STEMI) criteria with suboptimal sensitivity, which could be potentially increased by consideration of the principle that each of the 12 ECG leads can be inverted to provide an additional lead with the opposite (180 degrees) orientation, generating a 24-lead ECG. Methods: The study population included 162 patients who underwent prolonged coronary occlusion during elective percutaneoas transluminal coronary angioplasty. Balloon occlusion was performed in the left anterior descending coronary artery (51 patients), in the right coronary artery (67 patients), or in the left circumflex coronary artery (44 patients). To be classified as indicative of the epicardial injury current of acute ischemia, the ECGs had to fulfill either the criteria of a consensus document from the American College of Cardiology or the European Society of Cardiology or thresholds for the inverted leads based on a population study from Scotland. Results: The addition of -V1, -V2, -V3, -aVL, -I, aVR, and -III increased sensitivity from 61% to 78% (P <= .01) and decreased specificity from 96% to 93% (P = .06). Conclusions: Addition of 7 leads from the 24-lead ECG, thus creating a 19-lead ECG, was found optimal for attaining high sensitivity while retaining high specificity when compared with the performance of the standard 12-lead ECG. (C) 2007 Elsevier Inc. All rights reserved

Many human peripheral VH5-expressing IgM+ B cells display a unique heavy-chain rearrangement.

International audienceThe immunoscope methodology has proven useful to analyze T-cell repertoires in mice and humans. We adapted it to the analysis of VH chains of human peripheral B cells by setting up a quantification of various VH and JH segments and the profiling of IgM-, IgG-, IgA- and IgE-expressing B cells. We then tested the hypothesis that the human B-cell and T-cell repertoires have a similar diversity of VH and V-beta rearrangements. We studied in more detail the VH5 family because it is not abundantly used, which facilitated the analysis. The data showed that the number of distinct VH5 rearrangements in all samples studied is close to the number of cells in the sample. This contrasts with T cells in which we previously showed that distinct V-beta rearrangements amount to a few percent of the number of T cells because each V-beta chain is on the average paired with approximately 25 alpha chains. Thus, in the VH5 family, the light chains add little quantitative diversity to that produced by the heavy chain alone. Whether this feature can be generalized to other VH chains is discussed

From autistic to artistic: An artist’s developmental pathway through the health and disability sector

This discussion paper describes the international career development of an emerging artist spanning France and the Antipodes. The research, carried out using participant observation and narrative methodologies, demonstrates how the artist’s passion was revealed via different engagement pathways in the visual arts with tangible outcomes. This involved the planning of novel, inspiring and accessible contexts for the artist to develop new social competencies. At the core of this intervention was the development of a network of formal and informal collaboration between international organisations. Many people on the autistic spectrum, due to social challenges, may never experience achievement within their communities. Participatory arts, however, offer unique prospects for contribution and recognition. This research demonstrates how intersectorial collaborations have the potential to generate new authentic inclusion opportunities for clients in the Health and Disability sector with benefits spreading to the community at large. It demonstrates how a passion for the arts paved the way from disengagement to contribution. The paper details how unique interventions were planned, rolled out and evaluated for their impact. Examples with unique outcomes to the artist, family, therapists, educators and organisations involved are discussed. These benefits have also spread in unpredicted ways, i.e. the artist being recognised for leadership qualities and becoming a role model