Effect of haemolysis on plasma and serum immunoglobulin estimations

Summary Plasma IgG, IgM and IgA estimations were carried out in blood samples with varying degrees of haemolysis, produced by controlled ultrasonication. Extent of haemolysis was determined by plasma haemoglobin, plasma potassium and packed cell volume; and plasma IgG, IgM and IgA estimations showed a steady and significant fall with increasing haemolysis. A calculated correction is proposed which compensates for the dilutional effect of haemolysis, during estimations of plasma and serum immunoglobulins.     

Description of an unusual enzymic activity cleaving the third component of complement]

A large enzymatic complex cleaving C3 (C3'ase) in the absence of magnesium (EDTA) has been partially characterized in two patients. On gel filtration EDTA-C3'ase was found in an 800 000 fraction containing antigenic C4, IgA and IgG in addition to alpha-2-macroglobulin and IgM normally present. EDTA-C3'ase was specifically neutralized by antibodies to IgG, IgA and C4. The characteristics of this unusual enzymatic complex are compatible with that of a C4b2a complex stabilized by its specific binding to an auto-antibody of the IgG and/or IgA class.     

Immunoglobulins in human fetal sera at different stages of gestation

Zusammenfassung Durch quantitative Immunodiffusion wurde der Gehalt an IgM, IgA und IgG in menschlichen Fötalseren untersucht. Der früheste Zeitpunkt, wo IgA entdeckt wurde, war bei einem prämaturen Embryo, der 41 cm lang war und 1680 g wog. In den Seren von am Termin geborenen Kindern konnte IgA in 37% nachgewiesen werden. IgG wurde in allen untersuchten Seren gefunden.

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Supported by a grant from the Sigrid Jusélius Foundation.     

Immunoglobulin synthesis by cord blood lymphocytes.

The IgG, IgA and IgM synthesis by adult peripheral blood and cord blood lymphocytes incubated alone and with pokeweed mitogen was quantitated. The cord blood lymphocytes produced no immunoglobulin even with mitogen stimulation while the adult peripheral blood lymphocytes responded to the mitogen with a significant (p less than 0.04) increase in immunoglobulin production.     

Immunoglobulin synthesis by cord blood lymphocytes

Summary The IgG, IgA and IgM synthesis by adult peripheral blood and cord blood lymphocytes incubated alone and with pokeweed mitogen was quantitated. The cord blood lymphocytes produced no immunoglobulin even with mitogen stimulation while the adult peripheral blood lymphocytes responded to the mitogen with a significant (p<0.04) increase in immunoglobulin production.     

Une IgA à coefficient de sédimentation 11 S dans les sécrétions externes de l'espèce bovine

Summary The sedimentation coefficient of a secretory IgA found in bovine colostrum and saliva is compared with that of IgG and IgM from the same colostrum. The IgA fraction gives a value of 10.8 S, whereas the major part of the IgG has a value of 7.1 S and the IgM 19.2 S. The sedimentation coefficient of the free secretory piece has also been determined: its value is 4.95 S.

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Ce texte est le résumé d'une communication faite à la Société Suisse de Biochimie le 17 mai 1969 (un rapport plus détaillé est sous presse dans «Nature»).     

Binding bovine immunoglobulins to anterior lobe cells of the hypophysis.

Cells of the anterior lobe of the bovine hypophysis, show an affinity for immunoglobulins IgG, IgA and IgM. The phenomenon either provides a message to stimulate cellular secretion or to excite mechanisms associated with the synthesis and release of Ig's or their determinants.     

Binding bovine immunoglobulins to anterior lobe cells of the hypophysis

Summary Cells of the anterior lobe of the bovine hypophysis, show an affinity for immunoglobulins IgG, IgA and IgM. The phenomenon either provides a message to stimulate cellular secretion or to excite mechanisms associated with the synthesis and release of Ig's or their determinants.This study was supported by a grant from the National Research council of Canada.     

Synthesis in vitro of immunoglobulins produced by different human mucous membranes

Riassunto Gli autori hanno dimostrato che alcune mucose della specie umana (mucosa congiuntivale, gengivale, nasale, vaginale e rettale) a contatto con l'ambiente esterno, sono in grado in vitro di sintetizzare le immunoglobuline (IgG, IgA, IgM) in diversa proporzione. La formazione di queste immunoglobuline può rivestire il significato di un meccanismo di difesa locale di tipo immunitario.     

Studies on the Dd antigen-antibody system. I. The nature of antigen Dd and its antibodies

Summary The nature of antigen Dd, an antigen present in the extracts of human dandruff which precipitates human sera selectively, and antibodies reacting with it are reported.This work was supported through U.G.C. Grant No. F.23-230/75/SR II. H.K. participated in this study, first as J.R.F. of U.G.C. and then as S.R.F. of I.C.M.R. We are grateful to Dr Baruch S. Blumberg for his invaluable suggestions and to Professor H. Walter for the gift of IgG, IgM and IgA immune sera.     

Arthus type inflammation with rat immunoglobulins

Résumé Étude comparative des proprietés biologiques des anticorps IgM, IgG₁ et IgG₂ du rat. Les résultats montrent que le pouvoir agglutinant et lytique des anticorps IgM est respectivement 37 et 100 fois supérieur à celui des deux classes d'anticorps IgG. Par contre, en ce qui concerne le phénomène d'Arthus, les anticorps IgM sont moins actifs que les anticorps IgG, si les rapports sont exprimés en poids. Si l'on calcule les rapports par nombre de molécules, les anticorps IgM sont aussi, dans ce cas, plus actifs que les IgG.     

IgM memory B cells: a mouse/human paradox

Humoral memory is maintained by two types of persistent cells, memory B cells and plasma cells, which have different phenotypes and functions. Long-lived plasma cells can survive for a lifespan within a complex niche in the bone marrow and provide continuous protective serum antibody levels. Memory B cells reside in secondary lymphoid organs, where they can be rapidly mobilized upon a new antigenic encounter. Surface IgG has long been taken as a surrogate marker for memory in the mouse. Recently, however, we have brought evidence for a long-lived IgM memory B cell population in the mouse, while we have also argued that, in humans, these same cells are not classical memory B cells but marginal zone (MZ) B cells which, as opposed to their mouse MZ counterpart, recirculate and carry a mutated B cell receptor. In this review, we will discuss these apparently paradoxical results.     

Affinity chromatography of human serum proteins using matrix bound lectin fromViscum album L.

Summary The D-galactose specific lectin fromViscum album L. reacts with serum proteins that contain the corresponding D-galactopyranosyl residues. By affinity chromatography of human serum on lectin-sepharose IgM, ₂-macroglobulin, haptoglobin and -lipoprotein were quantitatively retained. Only parts of IgA, IgG and transferrin were retarded. The other serum proteins are unbounded as albumin, ₁A– and ₁C.     

Serodiagnosis of viral hepatitis A: rise in antibody titre and evaluation of three methods for detecting early and late antibodies

A serological investigation was made on patients with viral hepatitis A and individuals with a past history of this disease. Titration of antibody in sequential samples was found to be of no help in diagnosis. Separation of early (IgM) from late (IgG) antibodies by protein A or by 2-mercaptoethanol did not prove to be convenient for the serodiagnosis. A chromatographic separation of late and early antibody was found to be satisfactory, and equivalent to a radioimmunoassay for IgM-antibodies.     

Specific and non-specific immunoglobulin synthesis in germfree mice immunized with ferritin by different routes

Résumé Après injection de ferritine de cheval, des souris C₂H axéniques développèrent des anticorps circulants ainsi que des immunoglobulines sans affinité pour l'antigène dans chacune des classes: IgA, IgM, IgG₁, et IgG₂. Après immunisation orale, la réponse spécifique fut exclusivement du type IgA, et la réponse non-spécifique principalement du type IgG₂ et IgA.

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Belgian American Educational Foundation Fellow.

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Staff Member of the Biology Division of Euratom, Euratom Publication No. 486.

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The Rega Institute for Medical Research, Louvain.     

Down's syndrome: changes in protein fractions of blood plasma

Summary A statistically significant decrease of prealbumin and statistically significant increases of alpha₂-macroglobulin and IgA were found in blood plasma of patients with Down's syndrome using quantitative crossed immunoelectrophoresis.We are indebted to Prof. T.C. Bøg-Hansen, University of Copenhagen, for the helpful discussion of our results.     

Aberrant O-glycosylation and anti-glycan antibodies in an autoimmune disease IgA nephropathy and breast adenocarcinoma

Glycosylation abnormalities have been observed in autoimmune diseases and cancer. Here, we compare mechanisms of aberrant O-glycosylation, i.e., formation of Tn and sialyl-Tn structures, on MUC1 in breast cancer, and on IgA1 in an autoimmune disease, IgA nephropathy. The pathways of aberrant O-glycosylation, although different for MUC1 and IgA1, include dysregulation in glycosyltransferase expression, stability, and/or intracellular localization. Moreover, these aberrant glycoproteins are recognized by antibodies, although with different consequences. In breast cancer, elevated levels of antibodies recognizing aberrant MUC1 are associated with better outcome, whereas in IgA nephropathy, the antibodies recognizing aberrant IgA1 are part of the pathogenetic process.     

Gewinnung von Leukocyten aus Rinderblut unter Verwendung von Wasser als Hämolytikum

Summary A method is described for separating the white elements of cow's blood. Addition of water causes a complete haemolysis. About 30 sec later, isotonic conditions are restored by admixing appropriate concentrations of physiological solutions. Differential centrifugation follows for separating the leucocytes.     

Celiac disease patient IgA antibodies induce endothelial adhesion and cell polarization defects via extracellular transglutaminase 2

We have recently found that celiac disease patient serum-derived autoantibodies targeted against transglutaminase 2 interfere with several steps of angiogenesis, including endothelial sprouting and migration, though the mechanism involved remained to be fully characterized. This study now investigated the processes underlying the antiangiogenic effects exerted by celiac disease patient antibodies on endothelial cells, with particular regard to the adhesion, migration, and polarization signaling pathway. We observed that celiac IgA reduced endothelial cell numbers by affecting adhesion without increasing apoptosis. Endothelial cells in the presence of celiac IgA showed weak attachment, a high susceptibility to detach from fibronectin, and a disorganized extracellular matrix due to a reduction of protein cross-links. Furthermore, celiac patient IgA led to secretion of active transglutaminase 2 from endothelial cells into the culture supernatants. Additionally, cell surface transglutaminase 2 mediated integrin clustering in the presence of celiac IgA was coupled to augmented expression of β1-integrin. We also observed that celiac patient IgA-treated endothelial cells had migratory defects and a less polarized phenotype when compared to control groups, and this was associated with the RhoA signaling pathway. These biological effects mediated by celiac IgA on endothelial cells were partially influenced but not completely abolished by R281, an irreversible extracellular transglutaminase 2 enzymatic activity inhibitor. Taken together, our results imply that celiac patient IgA antibodies disturb the extracellular protein cross-linking function of transglutaminase 2, thus altering cell-extracellular matrix interactions and thereby affecting endothelial cell adhesion, polarization, and motility.     

Comparative study of cysteine peptides of monomers and polymers of IgA]

The cysteinyl peptides of monomeric and polymeric IgA were studied by comparative autoradiography. Autoradiographies of polymeric IgA (containing or lacking J chain) showed an extra cysteinyl peptide which was never found in the monomeric forms. A similar peptide was obtained when reduced IgA was cleaved by BrCN. The possible identity of this fragment is discussed.