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PubMed1985

Antispermatozoal antibodies in human follicular fluid.

The possibility of antispermatozoal antibodies in women having significant effects in the higher regions of the female reproductive tract has been investigated. Follicular fluids (FF) and sera taken at the time of oocyte recovery from women undergoing in vitro fertilisation and embryo transfer (IVF-ET) were tested for the presence of antispermatozoal antibodies, and the concentrations of IgM, IgG, IgA, and complement C3 were determined. The concentrations of immunoglobulins and C3 in FF were consistent with transudation from serum inversely proportional to molecular weight. Titres of agglutinating and immobilizing antibodies in FF were usually one or two dilution steps below those of serum except where immobilizing activity was associated with IgM. IgG:IgA ratios were lower in FF from women with antispermatozoal antibodies, suggesting local production or enhanced transudation of IgA; however, a secretory component could not be detected in any of the follicular fluids in this study. Two women with antispermatozoal antibodies and infertility in excess of 5 years had successful IVF-ET and have delivered healthy infants.

Antibody Specificity↗
PubMed1985

Induction of the shaking phenomenon by IgA class antispermatozoal antibodies from serum.

Serum was obtained from a woman with a high (greater than 1000) titre of antispermatozoal antibody of IgA immunoglobulin class determined by the indirect immunobead test (IBT). It was found that the serum could sensitize normal sperm to give a strong shaking reaction in the semen-cervical mucus contact test (SCMCT). The capacity to induce shaking was retained after absorption of the serum with protein A-sepharose, but lost after absorption with rabbit antihuman IgA. The results therefore suggest that antispermatozoal antibodies of IgA class from serum can induce shaking, and are consistent with the possibility that the Fc fragment (rather than secretory component or J-chain) may be important for induction of shaking in the conventional SCMCT.

Antibodies↗
PubMed1992

The glomerular peripolar cell--an immunohistochemical study.

The peripolar cell is a recently described glomerular epithelial cell which may be a new secretory component of the juxtaglomerular apparatus (JGA). The purposes of this study were to identify immunohistochemical markers specific for peripolar cells and to elucidate the composition of their cytoplasmic granules. We examined tissue from normal human and sheep kidneys with a variety of monoclonal antibodies and antisera. A minority of peripolar cells showed immunoreactivity for vimentin but no other intermediate filament. Neuroendocrine markers were negative. The granules of peripolar cells contain a variety of plasma proteins with the exception of IgM. It is likely that peripolar cells absorb plasma proteins from the glomerular filtrate. The reason for this is uncertain; however, their unique position at the vascular pole of normal kidneys suggests a specialized function.

Animals↗
PubMed1978

A modified Sperber technique for direct estimation of true renal tubular excretion fraction.

The Sperber technique in the hen is particularly suitable for the study of renal tubular secretion. However, results obtained with this technique vary considerably, due to an unpredictable and highly variable shunting of renal portal blood. In an attempt to get a total and stable renal perfusion by portal blood from the leg, appropriate shunt vessels were ligated. This procedure was found to force all portal blood from the leg to perfuse the ligated kidney, without affecting the symmetry of glomerular filtration or renal clearance of 125-I-Na-o-iodohippurate between the kidneys. In conclusion, the abolition of renal portal shunt flow allows use of the Sperber technique for a direct estimation of the true tubular excretion fraction (TTEF) of a substance. Thus, TTEFPAH, a measure of the tubular excretion efficiency of para-amino-hippuric acid, was found to be about 70%. The stable renal perfusion in ligated animals will also facilitate comparative studies of renal tubular excretion in the hen. Moreover, no animal has to be rejected due to a low renal perfusion of portal blood. Furthermore, the use of ligated hens makes it unnecessary to use markers for the renal perfusion of portal blood when steady-state experiments are performed. Finally, the total renal perfusion of portal blood in ligated animals will facilitate the demonstration of a secretory component in the renal handling of substances with a low affinity for the renal transport system.

Animals↗
PubMed1996

History of oral tolerance and mucosal immunity.

Mucosal immunity depends on antigen stimulation in specialized lymphoepithelial structures such as the Peyer's patches. Although these inductive compartments were discovered more than 300 years ago, their functional role has become clear only over the last few decades. Research on homing of primed lymphoid cells to the intestinal mucosa began with animal experimentation in the 1960s and 1970s and has recently been brought to the molecular level. The major effector substance of mucosal immunity is secretory IgA (SIgA). The first evidence for its local antibody activity was obtained in humans in 1922, but its unique properties were not defined until the mid-1960s. Several models were subsequently proposed for selective external transport of IgA involving the secretory component (SC). In the early 1970s SC was suggested to act as a transmembrane polymeric Ig receptor common for dimeric IgA and pentameric IgM; this transport mechanism has now been confirmed by detailed studies at the level of cellular/molecular biology. Although SIgA antibodies performing immune exclusion are the main goal for exploitation of the mucosal immune system by oral vaccination, little is known about the precise mechanisms for induction of mucosal immunity against soluble proteins and chemicals. A peripheral immunosuppressive effect of oral immunization with such substances was apparently exploited by ancient people, and "oral tolerance" has since 1910 been subjected to numerous feeding experiments in rodents. The basis for the whole phenomenon appears to be intact epithelial barrier. Mucosal induction of suppression may in the future be exploited not only to modulate autoimmune diseases through the gut but also to prevent the development of IgE-mediated allergy and other untoward immune reactions by way of the respiratory tract.

Administration, Oral↗
PubMed1983

Renal disposition of moxalactam in experimental animals as revealed by stop-flow analysis.

The mechanisms of moxalactam excretion were studied by stop-flow analysis in dogs, monkeys, and rabbits. In dogs, the amount of moxalactam excreted in the urine was almost equal to that estimated by glomerular filtration. There was no specific moxalactam peak corresponding to the p-aminohippuric acid (PAH) peak in the stop-flow patterns of the dogs. The PAH peak disappeared with administration of probenecid, but the moxalactam stop-flow pattern showed no change. In monkeys, no specific moxalactam peak corresponding to the PAH peak could be detected. In the stop-flow pattern of the rabbit, the peak moxalactam concentration corresponded with that of PAH and disappeared with probenecid. These results suggest that in dogs and monkeys renal excretion of moxalactam takes place mostly through glomerular filtration. In rabbits, however, there is a small renal tubular secretory component added to the primary element, glomerular filtration. These observations point to differences in the mechanisms of moxalactam excretion in different animal species.

Animals↗
PubMed1995

Nasopharyngeal antibodies to pneumococcal pneumolysin in children with acute otitis media.

Pneumolysin, an intracellular protein toxin of all clinically relevant pneumococcal serotypes, is released in vivo during the autolysis of pneumococci and is believed to pave the way for intact pneumococci to invade and cause disease. Therefore, antibodies to pneumolysin should prevent its destructive function. We measured antibodies to pneumococcal pneumolysin in acute- and convalescent-phase nasopharyngeal aspirate samples of 120 children (median age, 2.5 years) with acute otitis media by enzyme immunoassay. Nasopharyngeal immunoglobulin M (IgM) and IgG class antibodies to pneumolysin were rarely detectable, whereas IgA class antibody was detected often, occurred independently of serum IgA antibody in serum, and correlated with the presence of the secretory component in pneumococcal antibody, indicating local production of IgA antibodies. Nasopharyngeal IgA antibody to pneumolysin was detected in 93% of the children already in the acute phase of otitis. Twenty percent of the children developed at least a threefold rise in the pneumolysin-specific IgA antibody concentration by the convalescent phase of otitis, with the youngest at 6 months of age, regardless of the pneumococcal findings in the nasopharynx or middle ear fluid. We suggest that nasopharyngeal IgA antibody to pneumolysin can be produced early in life by pneumococcal colonization.

Acute Disease↗
PubMed1999

Validation of a gastrointestinal explant system for measurement of mucosal antibody production.

A gastrointestinal explant culture system was developed and compared to the mononuclear cell extraction and enzyme-linked immunospot assay method for measurement of immunoglobulin A (IgA) and IgG antibody-secreting cells (ASCs) in gastric antral and duodenal biopsies of non-Helicobacter pylori-infected volunteers. IgA and IgG were detected in explant supernatants during 6 to 7 days of culture in all subjects. IgA containing secretory component was also detected throughout the culture period, although peak production occurred only in the first 3 days. During 7 days of culture, the cumulative geometric mean IgA levels produced were 2.2 and 8.02 microg/ml/10 mg of antral and duodenal biopsy tissues, respectively, while the cumulative geometric mean IgG levels were 1.54 and 2.92 microg/ml/10 mg of antral and duodenal biopsy tissues, respectively. Cycloheximide treatment resulted in a >90% reduction in both immunoglobulin classes after 6 days of treatment compared to levels in untreated controls. The detection of IgA and IgG ASCs extracted from biopsies on days 1 and 6 of culture confirmed that the antibody detected was derived from mucosal lamina propria. The IgA and IgG ASC responses were positively correlated with antibody concentrations detected in culture supernatants (r = 0.87 and 0.85, respectively). These results validate the potential usefulness of our gastrointestinal explant system for the evaluation of mucosal effector B-cell function.

Adolescent↗
PubMed1972

Identification and quantitation of equine serum and secretory immunoglobulin A.

Immunoglobulin A (IgA) was demonstrated in equine serum and secretions. This immunoglobulin had a molecular weight extending from 150,000 to 700,000 and reacted with specific antihuman alpha-chain antiserum. Antigenic determinants specific for secretory IgA were demonstrated and found to be absent on serum IgA. Antigen binding activity was detected in IgA from tears. Purified IgA was antigenically distinct from equine IgG, IgM, IgG(T), and aggregating immunoglobulin. Quantitative studies demonstrated that IgA was the predominant immunoglobulin in tears and milk but not in colostrum. The electrophoretic mobility, size, presence of secretory component, and reaction with specific antihuman alpha-chain antiserum demonstrates that this immunoglobulin is the equine homologue of human IgA.

Animals↗
PubMed2005

Antigenic specificity of the mucosal antibody response to Moraxella catarrhalis in chronic obstructive pulmonary disease.

Moraxella catarrhalis is an important human mucosal pathogen causing otitis media in children and lower respiratory tract infection in adults with chronic obstructive pulmonary disease (COPD). Little is known about the mucosal antibody response to M. catarrhalis in adults with COPD. In this study, 10 pairs of well-characterized sputum supernatant samples from adults with COPD who had acquired and subsequently cleared M. catarrhalis from their respiratory tracts were studied in detail in an effort to begin to elucidate potentially protective immune responses. Flow cytometry analysis was used to study the distribution of immunoglobulin isotypes in paired preacquisition and postclearance sputum samples. The results showed that immunoglobulin A (IgA) is the predominant M. catarrhalis-specific immunoglobulin isotype and that the sputum IgA contains a secretory component, indicating that it is locally produced at the mucosal site. Most patients made new sputum IgA responses to the adhesins UspA1 and Hag, along with the surface protein UspA2. A smaller proportion of patients made new sputum IgA responses to the iron-regulated proteins TbpB and CopB and to lipooligosaccharide. These results have important implications in understanding the mucosal immune response to M. catarrhalis in the setting of COPD and in elucidating the elements of a protective immune response.

Antibodies, Bacterial↗
PubMed1974

Acceleration of dextransucrase activity of Streptococcus mutans by secretory immunoglobulin A.

The effect of immunoglobulins on the activity of dextransucrase purified from Streptococcus mutans strain HS-6 is described. When human salivary immunoglobulin A (IgA) or colostral IgA, either natured or denatured, was incubated with dextransucrase, the rate of the dextran synthesis was markedly accelerated, whereas human serum IgA or IgG neither accelerated nor inhibited the enzyme activity. The results suggest that a portion unique for secretory IgA, the secretory component, might be related to the enzyme acceleration. On the other hand, specific rabbit antiserum against the dextransucrase inhibited completely dextran synthesis by the enzyme.

Animals↗
PubMed1986

Suppression of growth and protein secretion defects in Escherichia coli secA mutants by decreasing protein synthesis.

We devised a new selection for conditionally lethal suppressors of secA mutants. This selection allows the isolation of both temperature-sensitive and cold-sensitive suppressor mutations, whereas previous studies were limited to nonlethal or cold-sensitive suppressor mutations. Two temperature-sensitive suppressor mutations lie in genes required for protein synthesis: asnS, the gene for the asparaginyl-tRNA synthetase, and divE, which encodes the tRNASer1. A previously characterized mutation in alaS, the gene for the alanyl-tRNA synthetase, suppresses the growth and secretion defects of a secA mutant. Although the primary effects of these suppressor mutations are different, it is likely that they cause suppression of secA mutations by altering the rate of protein synthesis, since the protein synthesis inhibitors, chloramphenicol and tetracycline, also suppress secA mutations. Chloramphenicol also suppresses the growth defect of certain other sec mutants. We postulate that the impaired secretory capacity of sec mutants can be offset by decreasing the rate of elongation of secreted proteins or by decreasing the total amount of secreted proteins per cell. The results indicate that our initial goal to identify cellular secretory components as suppressors of secA mutations might be difficult to achieve because of a high frequency of nonspecific suppressors that alter protein synthesis. Unexpectedly, the suppressor approach provides a direct genetic selection for mutants in protein synthesis.

Bacterial Proteins↗
PubMed1999

Genetic and transcriptional analyses of the Vibrio cholerae mannose-sensitive hemagglutinin type 4 pilus gene locus.

The mannose-sensitive hemagglutinin (MSHA) of the Vibrio cholerae O1 El Tor biotype is a member of the family of type 4 pili. Type 4 pili are found on the surface of a variety of gram-negative bacteria and have demonstrated importance as host colonization factors, bacteriophage receptors, and mediators of DNA transfer. The gene locus required for the assembly and secretion of the MSHA pilus has been localized to a 16.7-kb region of the V. cholerae chromosome. Sixteen genes required for hemagglutination, including five that encode prepilin or prepilin-like proteins, have been identified. Examination of MSHA-specific cDNAs has localized two promoters that drive expression of these genes. This evidence indicates that the MSHA gene locus is transcriptionally organized into two operons, one encoding the secretory components and the other encoding the structural subunits, an arrangement unique among previously characterized type 4 pilus loci. The genes flanking the MSHA locus encode proteins that show homology to YhdA and MreB of Escherichia coli. In E. coli, the yhdA and mreB genes are adjacent to each other on the chromosome. The finding that the MSHA locus lies between these two E. coli homologs and that it is flanked by a 7-bp direct repeat suggests that the MSHA locus may have been acquired as a mobile genetic element.

Bacterial Proteins↗
PubMed1984

Efficient coating of the solid phase with rotavirus antigens for enzyme-linked immunosorbent assay of immunoglobulin A antibody in feces.

Sensitivity of the enzyme-linked immunosorbent assay for detecting serum antibodies to rotavirus was greatly enhanced when rotavirus particles were fragmented by chaotropic agents (NaSCN or guanidine hydrochloride) before adsorption of the antigens to the solid phase. For detecting fecal antibodies, the addition of fetal calf serum to the diluent was further needed to protect the antigens from the proteolytic activity of feces. With this technique, we readily detected immunoglobulin A antibody in feces from infantile gastroenteritis patients. Rate-zonal centrifugation of feces revealed that immunoglobulin A antibody activity sedimented with two peaks: one at 11S with a secretory component and another sedimenting slower than 7S, presumably as Fab portions.

Antibodies, Viral↗
PubMed1994

Cervical antibodies in patients with oral herpes simplex virus type 1 (HSV-1) infection: local anamnestic responses after genital HSV-2 infection.

Herpes simplex virus (HSV)-specific immunoglobulin A, immunoglobulin G, and secretory-component-containing immunoglobulins were identified in cervical and salivary secretions from six subjects with oral HSV type 1 (HSV-1) infections. Anamnestic cervical and salivary antibody responses were detected in two HSV-1-seropositive women with newly acquired genital HSV-2 infections. These data implicate the common mucosal immune system in antibody responses to HSV.

Adult↗
PubMed2006

Role of phosphocholine cytidylyltransferase alpha in lung development.

Lung development depends upon the differentiation and expansion of a variety of specialized epithelial cell types, including distal type I and type II pneumocytes in the late term. Previous studies have shown a strict dependence on the choline cytidylyltransferase alpha isoform (CCTalpha) to mediate membrane phospholipid formation in cultured cells and during preimplantation embryogenesis. CCTalpha expression is highest in lung, and there has long been speculation about its precise role, due to the dual requirement for phospholipid in proliferating cell membranes and for lung surfactant production from alveolar type II cells. We investigated the function of CCTalpha in lung development, using an inducible, epithelial cell-specific CCTalpha knockout mouse line. Deletion of CCTalpha beginning at embryonic day 7.5 did not restrict lung development but resulted in severe respiratory failure at birth. Alveolar lavage and lung lipid analyses showed significant decreases in the major surfactant phospholipid, dipalmitoyl-phosphatidylcholine. The fatty acids destined for the surfactant phospholipid were redirected to an expanded triglyceride pool. Transcripts encoding type II cell-specific markers were expressed in the knockout mice, indicating the expected progression of differentiation in lung epithelia. However, surfactant protein levels were reduced, with the exception of that for surfactant protein B, which was elevated. Ultrastructural analysis of the type II cells showed Golgi complex abnormalities and aberrant lamellar bodies, which deliver surfactant lipid and protein to the alveolar lumen. Thus, CCTalpha was not required for the proliferation or differentiation of lung epithelia but was essential for the secretory component of phospholipid synthesis and critical for the proper formation of lamellar bodies and surfactant protein homeostasis.

Animals↗
PubMed1994

Yersinia-specific antibodies in serum and synovial fluid in patients with Yersinia triggered reactive arthritis.

OBJECTIVES: To further evaluate the role of bacterial antigens in triggering inflammation in the joint in patients with reactive arthritis by studying local antibody synthesis in the joint. METHODS: Yersinia-specific antibodies in paired serum and synovial fluid samples from 29 patients with yersinia triggered reactive arthritis were studied using an enzyme linked immunosorbent assay (ELISA), an inhibition ELISA with six monoclonal antibodies against lipopolysaccharide or released proteins of yersinia and immunoblotting. Antibodies of IgM, IgG and IgA classes, as well as antibodies of IgA subclasses and those containing secretory component were measured against the lipopolysaccharide and the sodium dodecyl sulphate extract of whole Yersinia enterocolitica O:3 bacteria. RESULTS: It was shown that yersinia-specific antibodies, as well as antibodies against other microbial antigens (rubella, measles, Bordetella pertussis, tetanus toxoid and Candida albicans) in synovial fluid mirror those in serum by concentration, by specificity and by distribution in classes and subclasses. CONCLUSION: These results do not suggest any strong local antibody production, but indicate that the majority of yersinia antibodies in the synovial fluid are derived from the circulation.

Adolescent↗
PubMed1977

Glucosamine synthetase activity of the colonic mucosa in ulcerative colitis and Crohn's disease.

Glucosamine synthetase is the first enzyme in glycoprotein biosynthesis, catalysing the formation of glucosamine-6-phosphate, from which N-acetylglucosamine is formed. The levels of this enzyme in normal human colonic mucosa (in colectomy specimens and rectal biopsies) were found to be 13-8 +/- 4-0 micron mol glucosamine synthesised/h/g wet wt. In the colonic mucosa in ulcerative colitis and Crohn's colitis the enzyme level was diminished when there was loss of epithelial cells in the mucosa, although not when there was just loss of goblet cells. In patients recovering from an acute attack of ulcerative colitis, the enzyme levels rose to a peak above the normal range, an effect which did not occur in patients who did not recover promptly. This recovery peak may be related to the synthesis of gastrointestinal mucus, or immunoglobulin, or the secretory component of IgA, all of which contain large amounts of N-acetylglucosamine.

Carbohydrate Epimerases↗