A Comprehensive Phenotypic and Functional Immune Analysis Unravels Circulating Anti-Phospholipase A2 Receptor Antibody Secreting Cells in Membranous Nephropathy Patients

Introduction: Primary membranous nephropathy (MN) is characterized by the presence of antipodocyte antibodies, but studies describing phenotypic and functional abnormalities in circulating lymphocytes are limited. Methods: We analyzed 68 different B- and T-cell subsets using flow cytometry in 30 MN patients (before initiating immunosuppression) compared with 31 patients with non-immune-mediated chronic kidney disease (CKD) and 12 healthy individuals. We also measured 19 serum cytokines in MN patients and in healthy controls. Lastly, we quantified the ex vivo production of phospholipase A2 receptor (PLA2R)-specific IgG by plasmablasts (measuring antibodies in culture supernatants and by the newly developed FluoroSpot assay [AutoImmun Diagnostika, Strasberg, Germany]) and assessed the circulating antibody repertoire by phage immunoprecipitation sequencing (PhIP-Seq). Results: After adjusting for multiple testing, plasma cells and regulatory B cells (BREG) were significantly higher (P < 0.05) in MN patients compared with both control groups. The percentages of circulating plasma cells correlated with serum anti-PLA2R antibody levels (P = 0.042) and were associated with disease activity. Ex vivo-expanded PLA2R-specific IgG-producing plasmablasts generated from circulating PLA2R-specific memory B cells (mBCs) correlated with serum anti-PLA2R IgG antibodies (P < 0.001) in MN patients. Tumor necrosis factor-alpha (TNF-alpha) was the only significantly increased cytokine in MN patients (P < 0.05), whereas there was no significant difference across study groups in the autoantibody and antiviral antibody repertoire. Conclusion: This extensive phenotypic and functional immune characterization shows that autoreactive plasma cells are present in the circulation of MN patients, providing a new therapeutic target and a candidate biomarker of disease activity

Enzima ramificante de hígado de rata : aislamiento, purificación y propiedades

Se describe un método rápido, simple y específico para determinar colorimetricamente el glucógeno en concentraciones que varían entre 0,15 y 1 mg/ml con un reactivo de I2 en Ik en presencia de sales. Este procedimiento colorimétrico puede ser utilizado para la determinación del glucógeno contenido en los tejidos. Se puede diferenciar un polisacárido del tipo del glucógeno de uno del tipo de amilopectina, determinando el λ máx. del complejo polisacárido - iodo. Se utilizó este método para medir la actividad de la enzina ramificante. La α-1,4-glucano, α-1,4-glucano 6-glucosiltransferasa ha sido purificada 35 veces respecto de los extractos de hígado de rata. Se logra separar la α-amilasa, por centrifugación de los extractos de hígado co elevado contenido en glucógeno, a alta veocidad. La acción enzimática sobre amilopectina es óptima en buffer climato 0,3 M a pH 6,4. Requiere sales y es inhibida por Mn++, Mg++ y p-ele[…] de sodio. La enzima ramificante de hígado puede utilizar tamibién como substratos anilosa y dextrina β-límite de amilopectina. Se describe un método para ensayar la enzima en presencia de α-anilosa.Fil:Krisman de Fischman, Clara Rebeca. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Divergent Diastereoselective Synthesis of Iridomyrmecin, Isoiridomyrmecin, Teucrimulactone, and Dolicholactone from Citronellol

The iridoid natural products iridomyrmecin, isoiridomyrmecin, teucriumlactone, and dolicholactone were prepared from citronellol using a divergent diastereoselective approach. Key steps include a highly diastereoselective enamine/enal cycloaddition and the selective reduction of masked aldehyde functionalities by ionic hydrogenation

Line-Field Confocal Optical Coherence Tomography (LC-OCT) for Skin Imaging in Dermatology

International audienceLine-field confocal optical coherence tomography (LC-OCT) is a non-invasive optical imaging technique based on a combination of the principles of optical coherence tomography and reflectance confocal microscopy with line-field illumination, which can generate cell-resolved images of the skin in vivo. This article reports on the LC-OCT technique and its application in dermatology. The principle of the technique is described, and the latest technological innovations are presented. The technology has been miniaturized to fit within an ergonomic handheld probe, allowing for the easy access of any skin area on the body. The performance of the LC-OCT device in terms of resolution, field of view, and acquisition speed is reported. The use of LC-OCT in dermatology for the non-invasive detection, characterization, and therapeutic follow-up of various skin pathologies is discussed. Benign and malignant melanocytic lesions, non-melanocytic skin tumors, such as basal cell carcinoma, squamous cell carcinoma and actinic keratosis, and inflammatory and infectious skin conditions are considered. Dedicated deep learning algorithms have been developed for assisting in the analysis of LC-OCT images of skin lesions

Isolation of 35 Mycobacteriophages and Genomic Analysis of the Novel Mycobacteriophage, Glass

Thirty-five new mycobacteriophages were isolated from soil samples collected on or nearby Hope College in Holland, Michigan. All were capable of infecting Mycobacterium smegmatis and produced a variety of plaque morphologies based on size, shape, and clarity, consistent with the isolation of an assortment of different phages. Both lytic and temperate phages appear represented in this collection. Purified phage stocks were used to prepare genomic DNA samples for restriction digest analysis. A comparison of those 35 digest results revealed few similarities among the group, further supporting our interpretation that most of the new phage isolates were distinct. One mycobacteriophage, Glass, was chosen for complete genome sequencing using the Illumina MiSeq platform and comparative genomic analysis. The predominant plaque produced by Glass at 32°C was turbid and 0.5-1.0mm in diameter, while plaque produced at 42°C was clear and 1.0-1.5mm in diameter. Genome sequence data for Glass revealed a relationship to a group of 12 mycobacteriophages in Cluster B2. The genome of Glass is 67.5 Kb, 69.0% GC, and contains 91 genes in agreement with the genome characteristics of closely related phage. A detailed analysis of the complete genome sequence and comparison with sequenced members of this small and unique group of mycobacteriophages is the subject of the second semester of this yearlong course and is presented

GWAS for serum galactose-deficient IgA1 implicates critical genes of the O-glycosylation pathway

Aberrant O-glycosylation of serum immunoglobulin A1 (IgA1) represents a heritable pathogenic defect in IgA nephropathy, the most common form of glomerulonephritis worldwide, but specific genetic factors involved in its determination are not known. We performed a quantitative GWAS for serum levels of galactose-deficient IgA1 (Gd-IgA1) in 2,633 subjects of European and East Asian ancestry and discovered two genome-wide significant loci, in C1GALT1 (rs13226913, P = 3.2 x 10-11) and C1GALT1C1 (rs5910940, P = 2.7 x 10-8). These genes encode molecular partners essential for enzymatic O-glycosylation of IgA1. We demonstrated that these two loci explain approximately 7% of variability in circulating Gd-IgA1 in Europeans, but only 2% in East Asians. Notably, the Gd-IgA1-increasing allele of rs13226913 is common in Europeans, but rare in East Asians. Moreover, rs13226913 represents a strong cis-eQTL for C1GALT1 that encodes the key enzyme responsible for the transfer of galactose to O-linked glycans on IgA1. By in vitro siRNA knock-down studies, we confirmed that mRNA levels of both C1GALT1 and C1GALT1C1 determine the rate of secretion of Gd-IgA1 in IgA1-producing cells. Our findings provide novel insights into the genetic regulation of O-glycosylation and are relevant not only to IgA nephropathy, but also to other complex traits associated with O-glycosylation defects, including inflammatory bowel disease, hematologic disease, and cancer