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At least 973 records · Page 54Linked to original sources
PubMed1980

Histologic and immunohistologic comparison of main and accessory lacrimal tissue.

Main and accessory lacrimal tissues from autopsy and biopsy specimens were compared histologically and immunohistologically. Formaldehyde-fixed, paraffin-embedded specimens were studied by light microscopy with hematoxylinand-eosin and PAS staining. Glutaraldehyde-fixed, Epon-embedded specimens were sectioned at 1 micron, stained with alkaline Giemsa, and studied by light microscopy. Specimens fixed in a solution of alcohol and acetic acid were stained by immunofluorescence techniques for lactoferrin, lysozyme, secretory component, and the immunoglobulins IgG, IgA, IgM, IgD, and IgE. The main and the accessory lacrimal tissues were identical histologically and had identical distributions of secretory products and immunoglobulin-containing plasma cells. The finding of myoepithelial cells in 1-micron sections of accessory lacrimal tissue indicates autonomic innervation in that tissue. This finding, in conjunction with the identical immunohistology, indicates a common source for unstimulated and stimulated tears.

Aged↗
PubMed2006

[The microbiological and immunological characteristics of disbiotic disturbances of the biotopes of the mucose membranes of the respiratory and urogenital tracts].

The study consisted in comparison of the microecology and the parameters of the humoral immunity of the biotopes of the respiratory and urogenital tracts under normal conditions and in inflammatory processes caused by bacterial agents. The study revealed significant changes in the microbiocenosis of the respiratory and urogenital tracts, caused by decline of indigenous microflora and increase of the content of conditionally pathogenic microorganisms. These changes depended on the degree of the infectious process severity. Measurement of the humoral immunity parameters revealed a significant correlation between the content of conditionally pathogenic microorganisms and the levels of M and A immunoglobulins, as well as secretory IgA and free secretory component (sc) in the vaginal secretions of patients with non-specific inflammatory diseases of the genital tract, as well as G and A immunoglobulins, secretory IgA, and sc in the saliva of patients with chronic inflammatory diseases of the respiratory tract.

Adolescent↗
PubMed1978

Secretory immunoglobulin deficiency in a family with inflammatory bowel disease.

A family with 4 of 10 first-degree relatives affected with inflammatory bowel disease (IBD) was studied to determine whether any distinct immunological abnormalities occur in the affected members, as compared with unaffected members of the family, normal controls, and other unrelated patients with IBD. Red cell blood type and HL-A phenotypes did not distinguish between healthy and affected members, although HL-A2, 32, B27, and B12 were the predominant haplotypes in members with IBD. There was no significant difference between the two groups in the lymphocyte subpopulation counts of T cells, B cells, and cells carrying Fc or complement receptors. The in vitro mitogen response, however, to phytohemagglutinin and pokeweed mitogen were depressed in the affected members. Serum IgA and C3 levels were significantly elevated in members with IBD compared to healthy subjects with values of 232 +/- 69 (mean +/- SD) versus 148 +/- 29 mg per dl for IgA (P less than 0.05) and 173 +/- 32 versus 115 +/- 22 mg per dl for C3 (P less than 0.025), respectively. Plasma and, to a lesser extent, peripheral lymphocytes from 2 affected members who were tested were cytotoxic to allogeneic colonic epithelial cells. Salivary IgA was normal in the affected family members and unrelated patients with IBD. However, the free secretory component of salivary IgA was absent or markedly depressed in family members, as well as in unrelated patients with ulcerative colitis. This deficiency of the secretory immune system appears to characterize more frequently ulcerative colitis than Crohn's disease and may compromise mucosal host defenses in IBD.

Adolescent↗
PubMed1984

Carbohydrate exposure on salmonella and E. coli bacteria after reaction with antibody IgG and secretory IgA (SIgA) assessed with fluorescent lectins.

The carbohydrate moieties exposed on enterobacteria before and after antibody binding have been tested with fluorescent lectins. Salmonella typhimurium 395 MS (S-type) and its Rd-mutant MR10 were coated with hyperimmune anti-MS and anti-MR 10 IgG, respectively. MR 10 bacteria and Escherichia coli O86 bacteria were coated with human colostral secretory IgA (SIgA). There was a conspicuous binding of some of the lectins to untreated bacteria not always closely related to the sugar composition of the outer membrane lipopolysaccharide (LPS) or other known sugar residues. Antibody IgG and SIgA binding modified the affinity for the lectins. The binding of some lectins was reduced, presumably by masking the bacterial sugars. Antibody IgG binding to S. typhimurium MS and R 10 enhanced the affinity for RCA-I (Gal) and to a smaller extent for WGA (GlcNAc) which may be explained by exposure of IgG oligosaccharide. Antibody SIgA binding to S. typhimurium R 10 and E. coli O86 enhanced the affinity for the above lectins to a larger extent as well as for Con A (Man, Glc). The corresponding sugars N-acetylglucosamine, mannose and glucose are present in the carbohydrate chain of the secretory component as well as in IgA indicating that when SIgA antibody binds its sugar components are exposed.

Carbohydrates↗
PubMed1969

Two distinct groups of immunoglobulin A(IgA) revealed by peptic digestion.

Serum IgA M-components, secretory IgA separated from colostrum, and IgA from serum of patients with cirrhosis of the liver were digested with pepsin at pH 4.1. The IgA M-components segregated into two groups on the basis of their relative rates of peptic digestion. Serum and colostral IgA were digested at a total rate intermediate to that of the two groups of IgA myeloma proteins. It appeared, however, that colostral IgA may have been initially more resistant to peptic digestion than serum IgA. The variability in the rate of peptic digestion was not related to electrophoretic mobility, light-chain type, or IgA subclass. Experimental conditions related to enzyme to substrate ratio or to the pH of the reaction mixture did not appear to explain the differences found.These findings indicate that (a) two groups of IgA proteins can be distinguished on the basis of susceptibility to proteolysis with pepsin, and (b) secretory piece confers, at most, only a minor increase in stability to the IgA molecule against the digestive action of pepsin.

Chemical Phenomena↗
PubMed1997

Src family-selective tyrosine kinase inhibitor, PP1, inhibits both Fc epsilonRI- and Thy-1-mediated activation of rat basophilic leukemia cells.

Cross-linking of the surface receptor with high affinity for IgE (Fc epsilonRI) by multivalent antigen/immunoglobulin E complexes, as well as aggregation of Thy-1 glycoprotein by monoclonal antibodies lead in rat basophilic leukemia cells, clone RBL-2H3, to tyrosine phosphorylation of several cellular proteins, followed by a release of secretory components. To investigate the molecular mechanisms of Fc epsilonRI- and Thy-1-mediated transmembrane signaling and to map a step at which they converge into a common secretory pathway, we used a novel Src family-selective tyrosine kinase inhibitor, 4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP1), and analyzed its inhibitory activity on cell activation. Here we show that in RBL-2H3 cells PP1 demonstrates substrate specificity for a Src family kinase Lyn. In immunocomplex kinase assays in vitro, PP1 inhibited the Lyn kinase activity at nanomolar levels without any effect on Syk kinase activity. However, in RBL cells activated via aggregation of Fc epsilonRI, phosphorylation of both Syk and Lyn kinases was inhibited. Fc epsilonRI- and Thy-1-mediated early (protein-tyrosine phosphorylation) and late (release of beta-hexosaminidase) activation events were similarly affected by PP1. The inhibition was specific for membrane receptor-mediated signaling and was not observed in cells activated by an exposure to pervanadate. The combined data suggest that activation of Lyn is the early activation step at which the Fc epsilonRI- and Thy-1-mediated activation pathways of mast cells and basophils may converge.

Animals↗
PubMed1982

Fc receptor for IgA on erythrocytes.

Fc receptor for human IgA was detected on rabbit, sheep and human ORh- red blood cells. This Fc alpha receptor was able to bind human secretory or myeloma IgA, IgA1 or IgA2 and alpha chains. The ligand binding was detected by complement mediated lysis and agglutination with specific anti-IgA serum. Blocking experiments showed the inability of Fab(IgA) fragment or of secretory component to inhibit the IgA binding.

Animals↗
PubMed2000

Assembly, secretion, and vacuolar delivery of a hybrid immunoglobulin in plants.

Secretory immunoglobulin (Ig) A is a decameric Ig composed of four alpha-heavy chains, four light chains, a joining (J) chain, and a secretory component (SC). The heavy and light chains form two tetrameric Ig molecules that are joined by the J chain and associate with the SC. Expression of a secretory monoclonal antibody in tobacco (Nicotiana tabacum) has been described: this molecule (secretory IgA/G [SIgA/G]) was modified by having a hybrid heavy chain sequence consisting of IgG gamma-chain domains linked to constant region domains of an IgA alpha-chain. In tobacco, about 70% of the protein assembles to its final, decameric structure. We show here that SIgA/G assembly and secretion are slow, with only approximately 10% of the newly synthesized molecules being secreted after 24 h and the bulk probably remaining in the endoplasmic reticulum. In addition, a proportion of SIgA/G is delivered to the vacuole as at least partially assembled molecules by a process that is blocked by the membrane traffic inhibitor brefeldin A. Neither the SC nor the J chain are responsible for vacuolar delivery, because IgA/G tetramers have the same fate. The parent IgG tetrameric molecule, containing wild-type gamma-heavy chains, is instead secreted rapidly and efficiently. This strongly suggests that intracellular retention and vacuolar delivery of IgA/G is due to the alpha-domains present in the hybrid alpha/gamma-heavy chains and indicates that the plant secretory system may partially deliver to the vacuole recombinant proteins expected to be secreted.

Brefeldin A↗
PubMed1990

Immune complexes as immunizing agents to increase the number of monoclonal antibody producing hybrids and to deviate the response to poorly immunogenic epitopes.

The use of immune complexes (IC) in an antibody excess, as immunizing agent, led to a large increase in the mouse polyclonal response to human SIgA. This enhanced response, as compared to SIgA alone, was analysed with mouse polyclonal anti-alpha chain antibodies (Ab). A kinetic study showed an early rise (between days 14 and 21) of the antibody response against the discontinuous epitopes of SIgA while the anti-IgA response increase was delayed. Induction of hybridomas with an IC consisting in SIgA containing an excess of anti-alpha chain Ab, increased 10-fold the number of positive wells. Moreover, two of these MAb were specific for weakly immunogenic epitopes. One recognized only SIgA (anti-C), i.e. the association between the alpha chain and the secretory component (SC), while the other mainly combined to IgA dimers (anti-P). Both these MAb will be useful tools for structural studies and for the dosage of secretory Ab.

Animals↗
PubMed1989

Secretory immunoglobulin A in sweat gland tumors.

The presence of immunoglobulin A (IgA) and secretory component (SC) was investigated in normal human skin and in cutaneous neoplasms including a variety of sweat gland tumors. Immunohistochemistry in normal sweat glands revealed the occurrence of secretory IgA (sIgA) as indicated by reactivity for IgA and SC in serial sections. The majority of 28 cases of sweat gland tumors could be demonstrated to retain their ability to produce IgA and SC. In normal as well as in neoplastic sweat glands heaviest staining for sIgA could be found in the lumina and at the surface of lining epithelia. This is comparable with the presence of sIgA in breast or intestinal neoplasms. In contrast other epidermal cysts or solid tumors were not labelled. In view of recent immunohistochemical studies the demonstration of IgA and SC may be of differentiating value in cutaneous glandular neoplasms.

Breast Neoplasms↗
PubMed1979

Regional deficiency of secretory IgA in a patient with combined immunodeficiency of the ADA deficient type.

The IgA system in a patient with SCID and ADA deficiency showed heterogeneity. Serum IgA and stool secretory IgA (SIgA) levels were normal, but with altered kappa/lambda and A1/A2 subclass ratios; IgA in saliva and urine was deficient. Amounts of secretory component were normal. Jejunal and rectal biopsies showed prominent lymphonodular hyperplasia, but no cells containing IgA. A normal serum IgA level therefore does not always predict an intact secretory IgA system.

Adenosine Deaminase↗
PubMed1990

The synthesis of proteoglycans by human T lymphocytes.

We have examined the proteoglycans produced by highly-purified cultures of human T-lymphocytes. The proteoglycans were metabolically labelled with [35S]sulphate and analysed in cellular and medium fractions using DEAE-cellulose chromatography, gel filtration and specific enzymatic and chemical degradations. The results showed that the T cells synthesized a relatively homogeneous, proteinase-resistant chondroitin 4-sulphate proteoglycan that accumulated in the culture medium during a 48 h incubation period. The cellular fraction contained a significant amount of free chondroitin sulphate chains that were not secreted into the medium. These polysaccharides were formed by intracellular degradation of proteoglycan in a chloroquine-sensitive process, indicating a requirement for an acidic environment. In contrast to chondroitin sulphate derived from proteoglycan, chondroitin sulphates synthesized on the exogenous primer, beta-D-xyloside, were mainly secreted by the cells. beta-D-Xylosides caused an 8-fold stimulation in the synthesis of chondroitin sulphate, but decreased the synthesis of proteoglycan by about 50%. These proteoglycans contained shorter chondroitin sulphate chains than their normal counterparts. The results indicate that although proteoglycans are mainly secretory components in human T-cell cultures, a specific metabolic step leads to the intracellular accumulation of free glycosaminoglycans. Separate functions are likely to be associated with the intracellular and secretory pools of chondroitin sulphate.

Cells, Cultured↗
PubMed1985

Circulating immune complexes containing secretory IgA in jejunoileal bypass disease.

Thirteen patients were studied after jejunoileal bypass (JIB) surgery. Seven developed arthritis and six did not. Circulating immune complexes containing IgG and IgA were detected in the sera of patients with and without arthritis. IgA complexes were shown to contain secretory component, a protein predominantly associated with intraluminal IgA, in significantly higher levels in patients with arthritis. Analytical ultracentrifugation showed complexes of approximately 10 X 8S, consistent with the size of secretory IgA. Arthritis after JIB appears to be associated with circulating immune complexes containing secretory IgA.

Acute Disease↗
PubMed1992

Exo1 and Exo2 proteins stimulate calcium-dependent exocytosis in permeabilized adrenal chromaffin cells.

In many cell types an increase in cytosolic calcium is the main signal for the exocytotic release of stored secretory components such as hormones and neurotransmitters. The site of action of calcium in exocytosis is not known, neither are the participating molecules. In the case of the intracellular membrane fusions that occur during transport through early stages of the secretory pathway, several cytosolic and peripheral membrane proteins are necessary. Permeabilized cells have been useful in understanding the requirements for calcium and nucleotides in regulated exocytosis and under certain conditions there is leakage of soluble protein components and run-down of the exocytotic response. This system can be used to identify the soluble proteins involved in exocytosis, one candidate in chromaffin cells being annexin II (calpactin). Here we use this assay to identify two other cytosolic protein factors that regulate exocytosis in permeabilized adrenal chromaffin cells, which we term Exo1 and Exo2. Exo1 from brain cytosol resolves on electrophoresis in SDS-polyacrylamide gels as a group of polypeptides of relative molecular mass approximately 30,000 and shares sequence homology with the 14-3-3 family of proteins. The ability of Exo1 to reactivate exocytosis is potentiated by protein kinase C activation and therefore Exo1 may influence the protein kinase C-mediated control of Ca(2+)-dependent exocytosis.

14-3-3 Proteins↗
PubMed1992

Secretory IgA are elevated in both saliva and serum of patients with various types of primary glomerulonephritis.

Secretory immunoglobulin A (IgA) was determined by means of an enzyme-linked immunosorbent assay (using as capture antibody an MoAb specific for secretory component) in saliva and serum from 46 patients with IgA mesangial nephritis (IgAGN), 36 with an idiopathic nephrotic syndrome (INS), 30 with an idiopathic membranous nephropathy (MGN) and 40 healthy controls. Secretory IgA levels were elevated in both saliva and serum of patients with primary glomerulonephritis (P < 0.05; Mann-Whitney test) regardless of the histological type of the primary glomerulonephritis. Salivary IgA1 and IgA2 levels were increased in the saliva of patients with IgAGN, INS and MGN (P < 0.05; Mann-Whitney test). The monomeric/total IgA ratio, and interferon-gamma and soluble IL-2 receptor levels, in saliva did not differ between the patients and controls (P > 0.05; Mann-Whitney test). We conclude that the mucosal immune system is activated in forms of glomerulonephritis other than IgAGN.

Glomerulonephritis↗
PubMed1998

Cellular and molecular mechanisms for induction of mucosal immunity.

The epithelial glycoprotein called secretory component (SC) is quantitatively the most important receptor of the immune system because it is responsible for external transport of locally produced polymeric IgA (pIgA) to generate remarkably large amounts of secretory IgA. Antibodies of this type constitute the major mediators of specific humoral immunity. Transmembrane SC belongs to the Ig supergene family and functions as a common pIg receptor, also translocating pentameric IgM externally to form secretory IgM. The B cells responsible for mucosal production of Ig polymers are initially stimulated in organized mucosa-associated lympho-epithelial structures, particularly the Peyer's patches in the distal small intestine; from these inductive sites they migrate ("home") as memory cells to exocrine tissues all over the body. Mucous membranes are thus furnished with secretory antibodies in an integrated way, ensuring a variety of specificities at every secretory effector site. There is currently great interest in exploiting this integrated or "common" mucosal immune system for oral vaccination against pathogenic infectious agents and also to induce tolerance in T cell-mediated auto-immune diseases. However, much remains to be learned about mechanisms for antigen uptake and processing necessary to elicit stimulatory or suppressive mucosal immune responses in humans. Moreover, evidence is emerging for the existence of considerable regionalization with regard to functional links between inductive sites and effector sites of mucosal immunity.

Animals↗
PubMed1980

Secretory immune response in intestinal mucosa and salivary gland after experimental infection of pigs with transmissible gastroenteritis virus.

Pigs 8 to 10 weeks of age were orally infected with transmissible gastroenteritis (TGE) virus or infected by inoculation of the virus into Thirty-Vella loops of jejunum. Concentrations of immunoglobulin (Ig) A, IgM, and IgG in serum, saliva, jejunal secretions, loop secretions, and bile were determined by solid-phase radioimmunoassay for TGE virus-infected and control pigs. A multiple-staining fluorescent antibody technique was used to determine the relative numbers of IgA-, IgM-, and IgG-producing plasma cells in intestinal mucosa, mesenteric lymph node, spleen, iliac lymph node, and submandibular salivary gland. The numbers of IgA- and IgM-producing plasma cells were greater in the jejunal mucosa of pigs infected and reinfected orally with TGE virus than in that of the control pigs. There was also an increase of IgA- and probably of IgM-cells in the submandibular salivary glands. Similar numerical increases of IgA- and IgM-cells were observed in jejunal mucosa and salivary glands of all pigs with intestinal loops whether exposed to TGE virus or not. Increases in plasma cells in mucosa or salivary gland were not associated with increases in concentrations of IgA or IgM in the respective secretions or serum. The data support the hypothesis that after stimulation, IgA- and IgM-producing cells leave the intestinal mucosa and are trapped by distant secretory epithelial. The absence of a simultaneous increased concentration of IgA and IgM in saliva and intestinal secretions indicates that in an intact epithelium, the transport of IgA and IgM mediated by secretory component is probably saturable.

Animals↗
PubMed1995

Electrophoretic, chromatographic and immunological studies of human urinary proteins.

Urinary proteins from both sexes were analyzed by high resolution two-dimensional gel electrophoresis (2-DE). For well reproducible 2-DE patterns, the samples were concentrated and desalted in one step by vacuum dialysis. A reference map for urine proteins was established by the analysis of urine from 10 healthy persons. Proteins in urine that share immunogenicity with serum proteins were identified by use of antibody to whole human-serum protein in an affinity-column fractionation of urine and differential analysis of the adsorbed (serum component) and unadsorbed (non-serum component) fractions. For identification of individual proteins, coelectrophoresis, immunoblotting and affinity chromatography with corresponding antibodies were used. Proteins identified in the map, besides known serum proteins, included: the subunit of Tamm-Horsefall protein, the secretory component of IgA, constant breakdown products of alpha 1-antitrypsin and retinol-binding protein, the five isoforms of the beta chain of human chorionic gonadotropin and the subunit of prostatic acid phosphatase. In addition, we could demonstrate three proteins which are markedly pronounced in female urine, especially pregnant women. To get more information about the native properties of various urinary proteins, they were separated into four main peaks according to their sizes using fast protein liquid chromatography equipment. Possible interpolypeptide disulfide bonds were studied using a nonreducing 2-DE system. 2-DE in combination with other methods seems to be a valuable tool for the characterization of urinary proteins in defined renal or extra-renal diseases. An example is given by analyzing the immune complexes from seven patients with a urinary tract infection.

Adult↗