Identification of Spectral Modifications Occurring during Reprogramming of Somatic Cells

Recent technological advances in cell reprogramming by generation of induced pluripotent stem cells (iPSC) offer major perspectives in disease modelling and future hopes for providing novel stem cells sources in regenerative medicine. However, research on iPSC still requires refining the criteria of the pluripotency stage of these cells and exploration of their equivalent functionality to human embryonic stem cells (ESC). We report here on the use of infrared microspectroscopy to follow the spectral modification of somatic cells during the reprogramming process. We show that induced pluripotent stem cells (iPSC) adopt a chemical composition leading to a spectral signature indistinguishable from that of embryonic stem cells (ESC) and entirely different from that of the original somatic cells. Similarly, this technique allows a distinction to be made between partially and fully reprogrammed cells. We conclude that infrared microspectroscopy signature is a novel methodology to evaluate induced pluripotency and can be added to the tests currently used for this purpose

Deficiency of the Adhesive Protein Complex Lymphocyte Function Antigen 1, Complement Receptor Type 3, Glycoprotein p150,95 in a Girl with Recurrent Bacterial Infections Effects on Phagocytic Cells and Lymphocyte Functions

Abstract A patient presenting delayed umbilical cord detachment, severe recurrent bacterial infections, and inability to form pus exhibited a profound defect in the expression of a-and 8-chains of the receptor for the C3bi fragment of C3 (CR3), lymphocyte function antigen I (LFA-1) molecule, and the p150,95 molecule found on neutrophils, monocytes, and lymphocyte membranes. This was shown by immunofluorescence studies using specific monoclonal antibodies, rosette formation with C3bi-coated erythrocytes, and immunoprecipitation for the LFA-1 complex. These membrane defects were responsible for abnormal phagocytic cell functions including adherence to nylon wool, cell movement, phagocytosis, and opsonized particle-induced oxidative response and for defective natural killer cell activity. In addition, lymphocyte function deficiencies previously unobserved in this disease were found. Cytolytic T lymphocyte activity was profoundly reduced; a-and y-interferon production were impaired. Finally, there was no antibody production to vaccinal antigens whereas the antibody responses to polysaccharides and to cytomegalovirus were found to be normal. The cytotoxic T cell deficiency could be expected from previous blocking experiments of this function with monoclonal antibodies to LFA-1 and is probably related to an extremely severe deficiency in LFA-1 expression in this patient. Anomalies in interferon and in antibody production suggest additional role(s) of the LFA-1 complex in monocyte/T lymphocyte/B lymphocyte cell interactions that have not yet been envisaged

The mouse gut T lymphocyte, a novel type of T cell . Nature, origin and traffic in mice in normal and graft-versus-host conditions

The normal intestinal mucosa contains, between the Peyer's patches (PP), ' a large number of lymphocytes present both within the lamina propria and between the epithelial cells (for review on the gut intraepithelial (IE) lymphocytes, see reference 1). In the mouse, it has previously been shown, using immunofluorescent staining to detect T lymphocytes on tissue sections, that most of these lymphocytes are of T nature (2). In addition, cell-transfer experiments showed that T lymphoblasts from thoracic duct lymph (TDL) or mesenteric lymph nodes (MLN), but not from peripheral lymph nodes (PLN), have the property of homing in the recipient's gut mucosa (2). In the present work, the conditions of appearance, nature, origin, and cell traffic of the mouse gut T lymphocytes (GTL) were studied, either in normal or germ-free mice, or by making use of two pathologic conditions which amplify some of the characteristics of the GTL system: (a) a model of graft-versus-host (GVH) reaction in which lethally irradiated F l mice are injected with parental thymocytes (3) : after 3-4 days during which the mucosa is strongly depleted in GTL as the result of the irradiation

SIDA : los hechos, la esperanza

Seleccionada por la OMS y la CCE, supervisada por el Departament de Sanitat de la Generalitat de Catalunya y con la colaboración del Institut Municipal de la Salut del Ayuntamiento de BarcelonaBoletín informativo sobre la enfermedad del SIDA en el que se esquematizan e ilustran los siguientes puntos: qué es el SIDA, cómo se transmite y principales modos de transmisión, cómo se detecta, situación de la epidemia en el mundo, concretando en occidente, en España y América, tratamiento y prevención, especialmente en niños y jóvenes. Se incluye un cuestionario, fechas y acontecimientos históricos sobre la enfermedad, los diez puntos más importantes a tener en cuenta, léxico y direcciones de interés a nivel nacional y autonómico.CataluñaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín, 5; 28014 Madrid; Tel. +34917748000; [email protected]