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PubMed1976

Immunochemistry of otitis media with effusion.

For investigation of the nature and origin of middle ear effusions, immunochemical studies were performed on more than 400 patients diagnosed as having otitis media with effusion. Although results of cellulose acetate and disc electrophoretic analyses and quantitation of IgG, IgA, and IgM suggested that proteins found in the effusions were derived for the most part from the serum, quantitative analysis of secretory IgA revealed the existence of appreciable amounts of secretory IgA in both serous and mucoid effusions. The antigenicity and subunit structure of the secretory IgA isolated from middle ear effusions were identical or very similar to those of secretory IgA obtained from other external secretions. Radioactive single radial diffusion analysis of IgE showed that the mean concentrations of IgE in effusions and sera were within normal ranges. Findings of this study suggest that the middle ear maintains the local immunologic defense system, that the middle ear effusion is at least partially an external secretion, and that IgE in middle ear effusions obtained from old patients, rather than being a local product, may be derived from the serum.

Adolescent↗
PubMed2006

Polymeric IgR knockout mice are more susceptible to mycobacterial infections in the respiratory tract than wild-type mice.

It is generally accepted that cellular, and not humoral immunity, plays the crucial role in defense against intracellular bacteria. However, accumulating data indicate the importance of humoral immunity for the defense against a number of intracellular bacteria, including mycobacteria. We have investigated the role of secretory IgA, the main isotype found in mucosal tissues, in protection against mycobacterial infection, using polymeric IgR (pIgR)-deficient mice. Characterization of the humoral response induced after intra-nasal immunizations with the mycobacterial antigen PstS-1 revealed a loss of antigen-specific IgA response in saliva from the knockout mice. IgA level in the bronchoalveolar lavage of knockout mice was similar to wild-type level, although the IgA antibodies must have reached the lumen by other means than pIgR-mediated transport. Infection with Mycobacterium bovis bacillus Calmette-Guérin (BCG) demonstrated that the immunized pIgR-/- mice were more susceptible to BCG infection than immunized wild-type mice, based on higher bacterial loads in the lungs. This was accompanied by a reduced production of both IFN-gamma and tumor necrosis factor-alpha (TNF-alpha) in the lungs. Additionally, the pIgR-/- mice displayed reduced natural resistance to mycobacterial infection proved by significantly higher bacterial growth in their lungs compared with wild-type mice after infection with virulent Mycobacterium tuberculosis. The knockout mice appeared to have a delayed mycobacteria-induced immune response with reduced expression of protective mediators, such as IFN-gamma, TNF-alpha, inducible nitric oxide synthase and regulated upon activation normal T cell sequence, during early infection. Collectively, our results show that actively secreted IgA plays a role in protection against mycobacterial infections in the respiratory tract, by blocking entrance of bacilli into the lungs, in addition to modulation of the mycobacteria-induced pro-inflammatory response.

Administration, Intranasal↗
PubMed1997

The Helicobacter pylori seroprevalence in blood donors related to Lewis (a,b) histo-blood group phenotype.

OBJECTIVE: To study a possible association of the Helicobacter pylori seroprevalence with ABO(H) and Lewis (a,b) blood group phenotypes in blood donors. DESIGN: A cross-sectional study of blood donors using ABO(H) and Lewis (a,b) blood group phenotype as predictors. METHODS: ABO(H) and Lewis (a,b) blood group phenotyping was performed with monoclonal antibody. The H. pylori immunoglobulin G (IgG) antibody relative activity was evaluated by enzyme-linked immunosorbent assay (ELISA) using acid glycine extract from H. pylori. SUBJECTS: One hundred and fifty-nine randomly selected blood transfusion donors. RESULTS: The individuals with Lewis (a+b-)/non-secretor phenotype showed a significantly higher proportion of the H. pylori-seronegative subjects and a lower IgG immune response to H. pylori antigens as compared with the individuals of Lewis (a-b+)/secretor phenotype. CONCLUSION: The Lewis (a,b) histo-blood group antigens are implicated in the mechanisms of naturally occurring resistance to H. pylori infection.

ABO Blood-Group System↗
PubMed2006

Structure of human salivary alpha-amylase crystallized in a C-centered monoclinic space group.

Human salivary alpha-amylase (HSA) is a major secretory protein component of saliva and has important biological functions, including the initial digestion of starch. HSA acts as a monomer and mediates the hydrolysis of alpha-1,4-glucosidic linkages in oligosaccharides. To date, all published crystal structures of HSA have been crystallized as monomers in space group P2(1)2(1)2(1). Here, the serendipitous purification, crystallization and ultimate structure determination of a HSA non-crystallographic symmetry (NCS) dimer, while attempting to purify human carbonic anhydrase VI (HCA VI) from saliva using an affinity resin for alpha-class carbonic anhydrases, is presented. On further investigation, it was shown that HSA could only be copurified using the affinity resin in the presence of HCA VI which is glycosylated and not the non-glycosylated HCA II. The identification of the HSA crystals was carried out by peptide mapping and mass spectrometry. HSA was shown to have crystallized as an NCS dimer in space group C2, with unit-cell parameters a = 150.9, b = 72.3, c = 91.3 A, beta = 102.8 degrees. The NCS dimer crystal structure is reported to 3.0 A resolution, with a refined Rcryst of 0.228. The structure is compared with the previously reported P2(1)2(1)2(1) monomer structures and the crystal packing and dimer interface are discussed.

Crystallization↗
PubMed1992

T and B cell responses following immunization with tetanus toxoid in IgA nephropathy.

The B and T cell responses were investigated in IgA nephropathy before and after immunization with tetanus toxoid (TT). Both IgA and IgG anti-tetanus toxoid antibodies were elicited, but the IgA antibodies were significantly greater in patients (92.6 +/- 11.7 ELISA units) than in the controls (49.2 +/- 7.5 ELISA units). This was associated with a significantly greater proportion of IgA+ B cells in patients than controls before immunization. However, a significant increase in the proportion of IgA1 binding CD4 and CD8 cells was also found. The proportion of CD3 cells with gamma delta T cell receptors (CD3+TCR gamma delta +), was significantly greater before immunization in the IgA nephropathy patients (37.0% +/- 2.4), compared with controls (10.0% +/- 2.3; P less than 0.001). Immunization with TT further enhanced the CD3+TCR gamma delta + cells in patients to 45.8% +/- 7.2 compared with controls (16.3% +/- 4.5), with a corresponding decrease in CD3+TCR alpha beta + cells in the patients (P less than 0.001). CD3+TCR gamma delta + cells are upregulated by common microbial antigens and clinical exacerbations of IgA nephropathy are frequently associated with mucosal infections and a rise in serum IgA concentration. The increased TCR gamma delta expression may be responsible for the enhanced IgA antibody response in IgA nephropathy. The increase in IgA antibodies may than exert a controlling effect by binding to augmenting T cells and thereby inhibiting their function.

Adult↗
PubMed2004

Retinoic acid enhances the gene expression of human polymeric immunoglobulin receptor (pIgR) by TNF-alpha.

In this study, the detailed mechanisms for the effects of vitamin A on the expression of polymeric immunoglobulin receptor (pIgR) were examined. Expression of the pIgR by tumour necrosis factor (TNF-alpha) was enhanced by the addition of all-trans retinoic acid (ATRA) or 9-cis retinoic acid (9CRA). This enhancement was mediated mainly by RARalpha, and regulated at the transcriptional level. Transcription factor nuclear factor-kappaB (NF-kappaB) binding and activation were not influenced by addition of ATRA. These data imply that RA, in combination with TNF-alpha, could up-regulate the expression of pIgR. In addition, we hypothesize that up-regulation of pIgR by RA is controlled through the RAR-dependent signalling pathway and that it plays a role in enhancement of mucosal immunity.

Blotting, Northern↗
PubMed1994

Genetic control of the antibody repertoire against excretory/secretory products and acetylcholinesterases of Dictyocaulus viviparus.

Outbred Dunkin-Hartley and inbred strain 2 and strain 13 guinea pigs were immunized with Dictyocaulus viviparus adult ES products prior to challenge with third stage larvae. Antibody responses of the three strains to adult ES products and the acetylcholinesterase (AChE) isoforms which they contain were examined. Using immunoprecipitation and ELISA, it was observed that responses in the three strains to adult ES products were distinct: considerable heterogeneity in the antibody repertoire was observed between outbred Dunkin-Hartley animals, with only slight variation occurring amongst the inbred individuals. Responses to the AChE isoforms were heterogeneous amongst individual outbred guinea pigs but were more consistent in inbred strain 2 and 13 animals in which strain-specific patterns of recognition were observed. Previous studies with nematode infections have indicated a role for the major histocompatibility complex in determining the nature and level of the immune response. As the inbred strains bear different alleles at the Class II region but are identical at the Class I region, the differences observed are likely to be due to genes mapping to the Class II locus. This is therefore the first report of genetic restriction of the antibody repertoire to secreted AChEs of a parasitic nematode.

Acetylcholinesterase↗
PubMed1977

Boosting of secretory IgA antibody responses in man by parenteral cholera vaccination.

The occurrence of specific antibodies to Vibrio cholerae lipopolysaccharide in serum, milk, and saliva of Pakistani women from a very low socioeconomic group was studied before and after a single subcutaneous cholera vaccination. Before immunization all women had low levels of specific antibodies in serum, primarily of IgM class, and in many cases cholera IgA angibodies were found in milk and saliva as well, indicating earlier natural exposure. The vaccination consistently induced a marked rise in serum antibody titer, and notably also produced significant titer increases in 70% of the milk and in 45% of the saliva samples. Whereas the serum antibodies induced were predominantly of the IgG class, secretory IgA was responsible for most of the titer increase in the secretions. The results indicate that parenteral cholera vaccination can boost local secretory IgA antibody responses in intestinally primed individuals.

Cholera Vaccines↗
PubMed1993

IgA and IgG subclass deficiency in a poor population in a developing country.

The levels of IgG, IgG subclasses, IgM and IgA were determined in serum from 17 patients with IgA deficiency and severe or frequent infections, allergy and/or autoimmunity (median age 7 years, range 2-19), 11 healthy IgA-deficient adults and 35 controls (median age 7 years, range 2-19). In serum from all groups IgG, IgM and IgA antibodies were determined against beta-lactoglobulin, E. coli O antigens and poliovirus type 1 antigen. In saliva of 15 IgA-deficient patients and 12 of the controls IgG, IgM and secretory component-carrying antibodies against E. coli O antigens and poliovirus type 1 were determined. The majority of the studied individuals lived under poor socio-economic conditions in Brazil, with consequent heavy microbial exposure. One IgA-deficient patient with rheumatoid arthritis also had IgG2 deficiency but no infectious problems. Four out of the 35 controls without any obvious infectious problems were found with IgA or IgG subclass deficiency. One of the 11 healthy IgA-deficient adults was low in the IgG2 subclass, one in IgG1 and one in IgG3. Those with symptomatic IgA deficiency had significantly higher serum IgG than the controls, especially in the age group 6-11 years. This latter group also had significantly increased serum IgG1 and IgG2 levels when compared with the age-matched controls. Salivary IgM antibodies to E. coli and poliovirus antigens were significantly higher among the symptomatic IgA-deficient individuals than among the controls. It is not clear at present whether these increased Ig levels are secondary to frequent infections and/or part of mechanisms that may compensate for the IgA deficiency.

Adolescent↗
PubMed1992

Characterization of a secreted glycoprotein of the immunoglobulin superfamily inducible by mitogen and oncogene.

The T1 gene is transiently activated by the Ha-ras (EJ) or v-mos oncoproteins and by mitogens in NIH3T3 fibroblasts. Its primary gene product of 337 amino acids (38 kDa) undergoes extensive post-translational modification. For biochemical analysis, the T1 gene product was over-expressed in a vaccinia virus system. Cells infected with a recombinant T1-vaccinia virus produce and secrete multiple proteins of 60-70 kDa which react with polyclonal antisera raised against two T1-specific peptides. Two lines of evidence suggest that the apparent size heterogeneity of the T1 protein is due to a variable carbohydrate content of 40-50% of the total molecular mass. First, in the presence of an inhibitor of N-glycosylation (tunicamycin), a single 38-kDa protein is detected by the antisera in the cells infected with T1-vaccinia virus. Second, glycosidase digestions show that T1 protein maturation involves glycosylation and sialylation. These post-translational modification steps appear to be similar in different types of cells.

Animals↗
PubMedDate not supplied

Immunoglobulins in human seminal plasma.

Single radial immunodiffusion has been used to evaluate immunoglobulins and secretory piece (SP) in human seminal plasma. Samples were collected from 90 healthy volunteers, 202 subjects submitted to vasectomy for contraceptive purposes, tested at various intervals after surgery, and 725 patients grouped according to selected andrological disorders. Results may be summarized as follows. In normal subjects IgG and IgA were constantly present (mean values +/- SD: 8.14 +/- 2.82 mg/dl; 1.91 +/- 1.03 mg/dl, respectively) while IgM were detected in trace amounts (from 0.7 to 3.3 mg/dl) in 10% of subjects, and negligible or absent in the remaining subjects. In vasectomized subjects IgG and IgA showed a significant increase only in the first 3 months after vasectomy, probably due to surgery. In andrological patients Ig showed an increase in cases with antisperm antibodies (A b) and in those with infections of genital tract and positive semen culture. On the basis of these findings and the secretory piece assay data the importance appears to be stressed of the local immunocompetent system at least in some andrological diseases.

Adult↗
PubMed2001

Neural components of distension-evoked secretory responses in the guinea-pig distal colon.

1. Using a Ussing chamber and neuronal retrograde tracing with 1,1'-didodecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) we characterized the afferent and efferent neuronal pathways which mediated distension-evoked secretion in the guinea-pig distal colon. 2. Acute capsaicin application (10 microM) to the serosal site of the Ussing chamber evoked a secretory response which was blocked by tetrodotoxin (1 microM), the combined application of the NK1 and NK3 receptor antagonists CP-99,994-1 and SR 142801 (1 microM), and by combined application of atropine (10 microM) and the VIP receptor antagonist VIP(6-28) (10 microM). Functional desensitization of extrinsic primary afferents by long-term application of capsaicin significantly diminished distension-evoked secretion by 46 %. 3. After functional desensitization by capsaicin, serosal application of gadolinium (100 microM) inhibited the distension-evoked chloride secretion by 54 %; the L-type Ca(2+) channel blocker nifedipine (1 microM) and the 5-HT(1P) receptor antagonist renzapride (1 microM) had no effect. The combination of atropine and VIP(6-28) or the combination of NK1 and NK3 receptor antagonists almost abolished distension-evoked secretion. 4. The secretory response evoked by electrical field stimulation, carbachol (1 microM) or VIP (1 microM) was not attenuated by gadolinium. Field stimulation-evoked chloride secretion was not affected by blockade of NK1 and NK3 receptors. 5. Twelve per cent of DiI-labelled submucosal neurones with projections to the mucosa were immunoreactive for choline acetyltransferase, substance P and calbindin and very probably represented intrinsic primary afferent neurones. 6. Distension-evoked chloride secretion was mediated by capsaicin-sensitive extrinsic primary afferents and by stretch-sensitive intrinsic primary afferent neurones. Both the extrinsic and intrinsic afferents converge on common efferent pathways. These pathways consist of VIPergic and cholinergic secretomotor neurones that are activated via NK1 and NK3 receptors.

Afferent Pathways↗
PubMed1986

Diagnosis of intrauterine infection by demonstration of antibody-coated bacteria in the amniotic fluid.

Immunofluorescence examination of amniotic fluid for the occurrence of antibody-coated bacteria was carried out in 72 consecutive women with premature rupture of the fetal membranes to assess this method in the diagnosis of intrauterine infection. Antibody-coated bacteria were demonstrated in 11 women with clinical signs of intrauterine infection, histological amnionitis and heavy growth of one bacterial species. The presence of intrauterine infection was considered possible in another 14 women. One patient had no clinical signs of infection, but positive histological and bacteriological evidence; antibody-coated bacteria were demonstrated in this patient, but not in the remaining 13 women. In 47 women clinical, histological and bacteriological signs of intrauterine infection were absent, and examinations for antibody-coated bacteria were negative in all of them. It is concluded that the demonstration of antibody-coated bacteria in amniotic fluid indicates the presence of intrauterine infection, and the examination may in some cases be positive before the appearance of clinical signs of infection.

Amniotic Fluid↗
PubMed1990

Antibody responses to parenteral and oral vaccines are impaired by conventional and low protein formulas as compared to breast-feeding.

The vaccine response to poliovirus, diphtheria and tetanus toxoids in relation to protein intake was studied in infants, either breast-fed or given low (1.1 g/100 ml) or conventional (1.5 g/100 ml) protein formula. Serum, saliva and faeces antibodies were measured by the enzyme-linked immunosorbent assay. Neutralizing poliovirus antibodies were determined. The serum, saliva and faeces antibody responses in the two formula-fed groups of infants did not differ significantly, but for the low protein formula group which had significantly higher serum neutralizing titres to poliovirus after the second vaccine dose than the conventional formula group. However, the breast-fed group had significantly higher antibody levels than the two formula-fed groups together: serum IgG to diphtheria toxoid (p less than 0.01) and serum neutralization of poliovirus (p less than 0.001) at 21-40 months of age, saliva secretory IgA to tetanus (p less than 0.01), diphtheria toxoid (p less than 0.01) and poliovirus (p less than 0.05), as well as faecal IgM to tetanus toxoid (p less than 0.05) and poliovirus (p less than 0.01 and p less than 0.05) at 3 and 4 months of age. Breast-fed infants thus showed better serum and secretory responses to peroral and parenteral vaccines than the formula-fed, whether with a conventional or low protein content.

Breast Feeding↗
PubMed1995

IgA and mucosal defense.

The traditional role of IgA antibodies in mucosal defense has been considered as providing an immune barrier to keep exogenous substances, including microbial pathogens, from penetrating the mucosa. In this way infections can be prevented. More recently, studies in vitro and in vivo are providing evidence to suggest that IgA may have additional roles in mucosal defense. For example, during their passage through the lining epithelial cells of mucous membranes en route to the secretions, IgA antibodies may have an opportunity to neutralize intracellular pathogens like viruses. Also, IgA antibodies in the mucosal lamina propria have opportunities to complex with antigens and excrete them through the adjacent mucosal epithelium, again by the same route to the secretions that is taken by free IgA. These latter functions could aid in recovery from infection.

Animals↗