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Sample records for pollen specific iga

  1. Pneumococcal IgA1 protease subverts specific protection by human IgA1.

    PubMed

    Janoff, E N; Rubins, J B; Fasching, C; Charboneau, D; Rahkola, J T; Plaut, A G; Weiser, J N

    2014-03-01

    Bacterial immunoglobulin A1 (IgA1) proteases may sabotage the protective effects of IgA. In vitro, both exogenous and endogenously produced IgA1 protease inhibited phagocytic killing of Streptococcus pneumoniae by capsule-specific IgA1 human monoclonal antibodies (hMAbs) but not IgA2. These IgA1 proteases cleaved and reduced binding of the the effector Fcα1 heavy chain but not the antigen-binding F(ab)/light chain to pneumococcal surfaces. In vivo, IgA1 protease-resistant IgA2, but not IgA1 protease-sensitive IgA1, supported 60% survival in mice infected with wild-type S. pneumoniae. IgA1 hMAbs protected mice against IgA1 protease-deficient but not -producing pneumococci. Parallel mouse sera with human IgA2 showed more efficient complement-mediated reductions in pneumococci with neutrophils than did IgA1, particularly with protease-producing organisms. After natural human pneumococcal bacteremia, purified serum IgG inhibited IgA1 protease activity in 7 of 11 patients (64%). These observations provide the first evidence in vivo that IgA1 protease can circumvent killing of S. pneumoniae by human IgA. Acquisition of IgA1 protease-neutralizing IgG after infection directs attention to IgA1 protease both as a determinant of successful colonization and infection and as a potential vaccine candidate. PMID:23820749

  2. A Pollen-Specific RALF from Tomato That Regulates Pollen Tube Elongation12[W][OA

    PubMed Central

    Covey, Paul A.; Subbaiah, Chalivendra C.; Parsons, Ronald L.; Pearce, Gregory; Lay, Fung T.; Anderson, Marilyn A.; Ryan, Clarence A.; Bedinger, Patricia A.

    2010-01-01

    Rapid Alkalinization Factors (RALFs) are plant peptides that rapidly increase the pH of plant suspension cell culture medium and inhibit root growth. A pollen-specific tomato (Solanum lycopersicum) RALF (SlPRALF) has been identified. The SlPRALF gene encodes a preproprotein that appears to be processed and released from the pollen tube as an active peptide. A synthetic SlPRALF peptide based on the putative active peptide did not affect pollen hydration or viability but inhibited the elongation of normal pollen tubes in an in vitro growth system. Inhibitory effects of SlPRALF were detectable at concentrations as low as 10 nm, and complete inhibition was observed at 1 μm peptide. At least 10-fold higher levels of alkSlPRALF, which lacks disulfide bonds, were required to see similar effects. A greater effect of peptide was observed in low-pH-buffered medium. Inhibition of pollen tube elongation was reversible if peptide was removed within 15 min of exposure. Addition of 100 nm SlPRALF to actively growing pollen tubes inhibited further elongation until tubes were 40 to 60 μm in length, after which pollen tubes became resistant to the peptide. The onset of resistance correlated with the timing of the exit of the male germ unit from the pollen grain into the tube. Thus, exogenous SlPRALF acts as a negative regulator of pollen tube elongation within a specific developmental window. PMID:20388667

  3. Reactivities of N-acetylgalactosamine-specific lectins with human IgA1 proteins.

    PubMed

    Moore, Jennifer S; Kulhavy, Rose; Tomana, Milan; Moldoveanu, Zina; Suzuki, Hitoshi; Brown, Rhubell; Hall, Stacy; Kilian, Mogens; Poulsen, Knud; Mestecky, Jiri; Julian, Bruce A; Novak, Jan

    2007-04-01

    Lectins are proteins with specificity of binding to certain monosaccharides or oligosaccharides. They can detect abnormal glycosylation patterns on immunoglobulins in patients with various chronic inflammatory diseases, including rheumatoid arthritis and IgA nephropathy (IgAN). However, lectins exhibit binding heterogeneity, depending on their source and methods of isolation. To characterize potential differences in recognition of terminal N-acetylgalactosamine (GalNAc) on IgA1, we evaluated the binding characteristics of several commercial preparations of GalNAc-specific lectins using a panel of IgA1 and, as controls, IgA2 and IgG myeloma proteins. These lectins originated from snails Helix aspersa (HAA) and Helix pomatia (HPA), and the plant Vicia villosa (VV). Only HAA and HPA bound exclusively to IgA1, with its O-linked glycans composed of GalNAc, galactose, and sialic acid. In contrast, VV reacted with sugars of both IgA subclasses and IgG, indicating that it also recognized N-linked glycans without GalNAc. Furthermore, HAA and HPA from several manufacturers differed in their ability to bind various IgA1 myeloma proteins and other GalNAc-containing glycoproteins in ELISA and Western blot. For serum samples from IgAN patients, HAA was the optimal lectin to study IgA1 glycosylation in ELISA and Western blot assays, including identification of the sites of attachment of the aberrant glycans. The galactose-deficient glycans were site-specific, localized mostly at Thr228 and/or Ser230. Because of the heterogeneity of GalNAc-specific lectins, they should be carefully characterized with appropriate substrates before undertaking any study. PMID:17275907

  4. Pollen loads and specificity of native pollinators of lowbush blueberry.

    PubMed

    Moisan-Deserres, J; Girard, M; Chagnon, M; Fournier, V

    2014-06-01

    The reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) is closely tied to insect pollination, owing to self-incompatibility. Many species are known to have greater pollination efficiency than the introduced Apis mellifera L., commonly used for commercial purposes. In this study, we measured the pollen loads of several antophilous insect species, mostly Apoidea and Syrphidae, present in four lowbush blueberry fields in Lac-St-Jean, Québec. To measure pollen loads and species specificity toward V. angustifolium, we net-collected 627 specimens of pollinators, retrieved their pollen loads, identified pollen taxa, and counted pollen grains. We found that the sizes of pollen loads were highly variable among species, ranging from a few hundred to more than 118,000 pollen grains per individual. Bombus and Andrena species in particular carried large amounts of Vaccinium pollen and thus may have greater pollination efficiency. Also, two species (Andrena bradleyi Viereck and Andrena carolina Viereck) showed nearly monolectic behavior toward lowbush blueberry. Finally, we identified alternative forage plants visited by native pollinators, notably species of Acer, Rubus, Ilex mucronata, Ledum groenlandicum, and Taraxacum. Protecting these flowering plants should be part of management practices to maintain healthy pollinator communities in a lowbush blueberry agroecosystem. PMID:25026677

  5. Development of an ELISA for sensitive and specific detection of IgA autoantibodies against BP180 in pemphigoid diseases

    PubMed Central

    2011-01-01

    Background Pemphigoids are rare diseases associated with IgG, IgE and IgA autoantibodies against collagen XVII/BP180. An entity of the pemphigoid group is the lamina lucida-type of linear IgA disease (IgA pemphigoid) characterized by IgA autoantibodies against BP180. While for the detection of IgG and IgE autoantibodies specific to collagen XVII several ELISA systems have been established, no quantitative immunoassay has been yet developed for IgA autoantibodies. Therefore, the aim of the present study was to develop an ELISA to detect IgA autoantibodies against collagen XVII in the sera of patients with pemphigoids. Methods We expressed a soluble recombinant form of the collagen XVII ectodomain in mammalian cells. Reactivity of IgA autoantibodies from patients with IgA pemphigoid was assessed by immunofluorescence microscopy and immunoblot analysis. ELISA test conditions were determined by chessboard titration experiments. The sensitivity, specificity and the cut-off were determined by receiver-operating characteristics analysis. Results The optimized assay was carried out using sera from patients with IgA pemphigoid (n = 30) and healthy donors (n = 105). By receiver operating characteristics (ROC) analysis, an area under the curve of 0.993 was calculated, indicating an excellent discriminatory capacity. Thus, a sensitivity and specificity of 83.3% and 100%, respectively, was determined for a cut-off point of 0.48. As additional control groups, sera from patients with bullous pemphigoid (n = 31) and dermatitis herpetiformis (n = 50), a disease associated with IgA autoantibodies against epidermal transglutaminase, were tested. In 26% of bullous pemphigoid patients, IgA autoantibodies recognized the ectodomain of collagen XVII. One of 50 (2%) of dermatitis herpetiformis patients sera slightly topped the cut-off value. Conclusions We developed the first ELISA for the specific and sensitive detection of serum IgA autoantibodies specific to collagen XVII in patients

  6. Comprehensive cell-specific protein analysis in early and late pollen development from diploid microsporocytes to pollen tube growth.

    PubMed

    Ischebeck, Till; Valledor, Luis; Lyon, David; Gingl, Stephanie; Nagler, Matthias; Meijón, Mónica; Egelhofer, Volker; Weckwerth, Wolfram

    2014-01-01

    Pollen development in angiosperms is one of the most important processes controlling plant reproduction and thus productivity. At the same time, pollen development is highly sensitive to environmental fluctuations, including temperature, drought, and nutrition. Therefore, pollen biology is a major focus in applied studies and breeding approaches for improving plant productivity in a globally changing climate. The most accessible developmental stages of pollen are the mature pollen and the pollen tubes, and these are thus most frequently analyzed. To reveal a complete quantitative proteome map, we additionally addressed the very early stages, analyzing eight stages of tobacco pollen development: diploid microsporocytes, meiosis, tetrads, microspores, polarized microspores, bipolar pollen, desiccated pollen, and pollen tubes. A protocol for the isolation of the early stages was established. Proteins were extracted and analyzed by means of a new gel LC-MS fractionation protocol. In total, 3817 protein groups were identified. Quantitative analysis was performed based on peptide count. Exceedingly stage-specific differential protein regulation was observed during the conversion from the sporophytic to the gametophytic proteome. A map of highly specialized functionality for the different stages could be revealed from the metabolic activity and pronounced differentiation of proteasomal and ribosomal protein complex composition up to protective mechanisms such as high levels of heat shock proteins in the very early stages of development. PMID:24078888

  7. Specific IgA Enhances the Transcytosis and Excretion of Hepatitis A Virus

    PubMed Central

    Counihan, Natalie A.; Anderson, David A.

    2016-01-01

    Hepatitis A virus (HAV) replicates in the liver, and is excreted from the body in feces. However, the mechanisms of HAV transport from hepatocytes to the gastrointestinal tract are poorly understood, mainly due to lack of suitable in vitro models. Here, we use a polarized hepatic cell line and in vivo models to demonstrate vectorial transport of HAV from hepatocytes into bile via the apical cell membrane. Although this transport is specific for HAV, the rate of fecal excretion in inefficient, accounting for less than 1% of input virus from the bloodstream per hour. However, we also found that the rate of HAV excretion was enhanced in the presence of HAV-specific IgA. Using mice lacking the polymeric IgA receptor (pIgR−/−), we show that a proportion of HAV:IgA complexes are transported via the pIgR demonstrating a role for specific antibody in pathogen excretion. PMID:26911447

  8. A pollen-specific calmodulin-binding protein, NPG1, interacts with putative pectate lyases

    PubMed Central

    Shin, Sung-Bong; Golovkin, Maxim; Reddy, Anireddy S. N.

    2014-01-01

    Previous genetic studies have revealed that a pollen-specific calmodulin-binding protein, No Pollen Germination 1 (NPG1), is required for pollen germination. However, its mode of action is unknown. Here we report direct interaction of NPG1 with pectate lyase-like proteins (PLLs). A truncated form of AtNPG1 lacking the N-terminal tetratricopeptide repeat 1 (TPR1) failed to interact with PLLs, suggesting that it is essential for NPG1 interaction with PLLs. Localization studies with AtNPG1 fused to a fluorescent reporter driven by its native promoter revealed its presence in the cytosol and cell wall of the pollen grain and the growing pollen tube of plasmolyzed pollen. Together, our data suggest that the function of NPG1 in regulating pollen germination is mediated through its interaction with PLLs, which may modify the pollen cell wall and regulate pollen tube emergence and growth. PMID:24919580

  9. Pollen specificity elements reside in 30 bp of the proximal promoters of two pollen-expressed genes.

    PubMed

    Eyal, Y; Curie, C; McCormick, S

    1995-03-01

    Functional analyses previously identified minimal promoter regions required for maintaining high-level expression of the late anther tomato LAT52 and LAT59 genes in tomato pollen. Here, we now define elements that direct pollen specificity. We used a transient assay system consisting of two cell types that differentially express the LAT genes and both "loss-of-function" and "gain-of-function" approaches. Linker substitution mutants analyzed in the transient assay and in transgenic plants identified 30-bp proximal promoter regions of LAT52 and LAT59 that are essential for their expression in pollen and that confer pollen specificity when fused to the heterologous cauliflower mosaic virus 35S core promoter. In vivo competition experiments demonstrated that a common trans-acting factor interacts with the pollen specificity region of both LAT gene promoters and suggested that a common mechanism regulates their coordinate expression. Adjacent upstream elements, the 52/56 box in LAT52 and the 56/59 box in LAT59, are involved in modulating the level of expression in pollen. The 52/56 box may be a target for the binding of a member of the GT-1 transcription factor family. PMID:7734969

  10. Pollen specificity elements reside in 30 bp of the proximal promoters of two pollen-expressed genes.

    PubMed Central

    Eyal, Y; Curie, C; McCormick, S

    1995-01-01

    Functional analyses previously identified minimal promoter regions required for maintaining high-level expression of the late anther tomato LAT52 and LAT59 genes in tomato pollen. Here, we now define elements that direct pollen specificity. We used a transient assay system consisting of two cell types that differentially express the LAT genes and both "loss-of-function" and "gain-of-function" approaches. Linker substitution mutants analyzed in the transient assay and in transgenic plants identified 30-bp proximal promoter regions of LAT52 and LAT59 that are essential for their expression in pollen and that confer pollen specificity when fused to the heterologous cauliflower mosaic virus 35S core promoter. In vivo competition experiments demonstrated that a common trans-acting factor interacts with the pollen specificity region of both LAT gene promoters and suggested that a common mechanism regulates their coordinate expression. Adjacent upstream elements, the 52/56 box in LAT52 and the 56/59 box in LAT59, are involved in modulating the level of expression in pollen. The 52/56 box may be a target for the binding of a member of the GT-1 transcription factor family. PMID:7734969

  11. NEW POLLEN-SPECIFIC RECEPTOR KINASES IDENTIFIED IN TOMATO, MAIZE AND ARABIDOPSIS: THE TOMATO KINASES SHOW OVERLAPPING BUT DISTINCT LOCALIZATOIN PATTERNS ON POLLEN TUBES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We previously characterized LePRKl and LePRK2, pollen-specific receptor kinases from tomato (Mushietti et al., 1998). Here we identify a similar receptor kinase from maize, ZmPRKl, that is also specifically expressed late in pollen development, and a third pollen receptor kinase from tomato, LePRK3...

  12. Variable Region Identical IgA and IgE to Cryptococcus neoformans Capsular Polysaccharide Manifest Specificity Differences*

    PubMed Central

    Janda, Alena; Eryilmaz, Ertan; Nakouzi, Antonio; Pohl, Mary Ann; Bowen, Anthony; Casadevall, Arturo

    2015-01-01

    In recent years several groups have shown that isotype switching from IgM to IgG to IgA can affect the affinity and specificity of antibodies sharing identical variable (V) regions. However, whether the same applies to IgE is unknown. In this study we compared the fine specificity of V region-identical IgE and IgA to Cryptococcus neoformans capsular polysaccharide and found that these differed in specificity from each other. The IgE and IgA paratopes were probed by nuclear magnetic resonance spectroscopy with 15N-labeled peptide mimetics of cryptococcal polysaccharide antigen (Ag). IgE was found to cleave the peptide at a much faster rate than V region-identical IgG subclasses and IgA, consistent with an altered paratope. Both IgE and IgA were opsonic for C. neoformans and protected against infection in mice. In summary, V-region expression in the context of the ϵ constant (C) region results in specificity changes that are greater than observed for comparable IgG subclasses. These results raise the possibility that expression of certain V regions in the context of α and ϵ C regions affects their function and contributes to the special properties of those isotypes. PMID:25778397

  13. A Novel Approach of Preventing Japanese Cedar Pollen Dispersal That Is the Cause of Japanese Cedar Pollinosis (JCP) Using Pollen-Specific Fungal Infection

    PubMed Central

    Hirooka, Yuuri; Akiba, Mitsuteru; Ichihara, Yu; Masuya, Hayato; Takahata, Yoshihiro; Suda, Tomohisa; Yada, Yutaka; Yamamoto, Shigehiro; Kubono, Takanori

    2013-01-01

    In Japan, Japanese cedar pollen dispersal is one of the major causes of pollinosis. Sydowia japonica is an ascomycetous fungus that grows exclusively on the male strobili of Japanese cedar, suggesting a possible mechanism for controlling pollen dispersal. To evaluate this possibility, eleven isolates of S. japonica were collected from around Japan and used as an inoculum to male strobili of Japanese cedar. The treatment demonstrated that the fungus infected only the pollen and prevented pollen dispersal. The fungus did not cause any additional symptoms to other parts of Japanese cedar, such as needles, stems, and buds. All S. japonica isolates collected around Japan could serve to control pollen dispersal. Periodic observation of the fungal pathogenesis with stereomicroscope and scanning electron microscope showed that hyphal fragments and conidia of S. japonica germinated on the surface of male strobili, and the germ tube entered pollen sacs through opening microsporophylls. Within the pollen sacs, the hyphae penetrated pollen gradually, such that all pollen was infected by the fungus by approximately one month before the pollen dispersal season. The infected pollen was destroyed due to the fungal infection and was never released. Our data suggests a novel approach of preventing pollen dispersal using pollen-specific fungal infection. PMID:23667533

  14. Selection of urinary sediment miRNAs as specific biomarkers of IgA nephropathy

    PubMed Central

    Duan, Zhi-Yu; Cai, Guang-yan; Bu, Ru; Lu, Yang; Hou, Kai; Chen, Xiang-Mei

    2016-01-01

    The miRNAs in urinary sediment are easy to obtain, which provides a new approach to searching for non-invasive biomarkers of IgA nephropathy (IgAN). Compared with normal controls (n = 3), 214 different miRNAs in the urinary sediment of IgAN (n = 9) were found by miRNA chip assay. By quantitative PCR analysis, miR-25-3p, miR-144-3p and miR-486-5p were confirmed to be significantly higher in IgAN (n = 93) than in the normal group (n = 82) or disease control (n = 40). These three miRNAs had good specificity and sensitivity for the diagnosis of IgAN by receiver operating characteristic curve analysis, in which the AUC value of miR-486-5p was the largest at 0.935. Urinary sediment miR-25-3p, miR-144-3p and miR-486-5p were demonstrated to be mainly derived from urinary erythrocytes, which were separated by CD235a magnetic beads. The increased expression of urinary erythrocyte miRNAs in IgAN patients was not associated with those in the blood erythrocytes. In addition, urinary supernatant microvesicles of miR-144-3p and miR-486-5p in the IgAN group were also significantly increased. This study showed that the miR-25-3p, miR-144-3p and miR-486-5p in urinary sediment were mainly derived from urinary erythrocytes, which could be non-invasive candidate biomarkers for IgA nephropathy. PMID:27000966

  15. Similarity of fine specificity of IgA anti-gliadin antibodies between patients with celiac disease and humanized α1KI mice.

    PubMed

    Sánchez, Daniel; Champier, Gaël; Cuvillier, Armelle; Cogné, Michel; Pekáriková, Aneta; Tlaskalová-Hogenová, Helena; Hoffmanová, Iva; Drastich, Pavel; Mothes, Thomas; Tučková, Ludmila

    2011-04-13

    Gliadins, and primarily α-gliadins containing several sequences such as aa 31-49, aa 56-88 (33-mer), aa 57-68, and aa 69-82, are critical in the induction of immune response or toxic reaction leading to the development of celiac disease (CLD). The role of IgA anti-gliadin antibodies (IgA AGA) is unknown. To this end, we prepared several humanized monoclonal IgA AGA using transgenic α1KI mice. Employing Pepscan with overlapping decapeptides of α-gliadin we observed a robust similarity between the specificity of humanized mouse monoclonal IgA AGA and IgA AGA from patients with florid CLD. The common immunodominant region included several sequential epitopes localized in the N-terminal part of α-gliadin (QFQGQQQPFPPQQPYPQPQPFP, aa 29-50, and QPFPSQQPYLQL, aa 47-58). Notably, IgA AGA produced by clones 8D12, 15B9, 9D12, and 18E2 had significant reactivity against sequences localized in the 33-mer, LQLQPFPQPQ (aa 56-65) and PQLPYPQPQPFL (aa 69-80). Humanized mouse monoclonal IgA AGA that have a known specificity are suitable as standard in ELISAs to detect serum IgA AGA of CLD patients and for studying the AGA pathogenic role in CLD, especially for analyzing the translocation of complex of specific IgA antibodies and individual gliadin peptides through enterocyte barrier. PMID:21366336

  16. Env-Specific IgA from Viremic HIV-Infected Subjects Compromises Antibody-Dependent Cellular Cytotoxicity

    PubMed Central

    Ruiz, María Julia; Ghiglione, Yanina; Falivene, Juliana; Laufer, Natalia; Holgado, María Pía; Socías, María Eugenia; Cahn, Pedro; Sued, Omar; Giavedoni, Luis; Salomón, Horacio; Gherardi, María Magdalena; Rodríguez, Ana María

    2015-01-01

    ABSTRACT Elucidating the factors that modulate HIV-specific antibody-dependent cellular cytotoxicity (ADCC) will help in understanding its role in HIV immunity. The aim of this study was to determine whether IgA could modify the magnitude of ADCC in HIV infection, abrogating its protective role. Plasma samples from 20 HIV-positive (HIV+) subjects enrolled during primary HIV infection (PHI), 10 chronically infected subjects (chronic), and 7 elite controllers (EC) were used. ADCC was determined by using a fluorometric ADCC assay, before and after removal of plasma IgA. Data were analyzed by using nonparametric statistics. ADCC was documented in 80% of PHI enrollment samples and in 100% of PHI 12-month, chronic, and EC samples; it peaked after acute infection, reached a plateau in chronic infection, and decreased after initiation of antiretroviral treatment (ART). Significant associations between ADCC and disease progression were found only after removal of plasma IgA from 12-month PHI samples: the magnitude of ADCC not only increased after IgA removal but also correlated with CD4+ T-cell preservation. This work provides evidence that gp120-specific IgA was capable of modifying ADCC responses during natural HIV infection for the first time and adds to similar evidence provided in other settings. Furthermore, it underscores the complexity of the ADCC phenomenon and will help in an understanding of its underlying mechanisms. IMPORTANCE Although the induction of ADCC-mediating antibodies in HIV-infected subjects has been extensively documented, the association of these antibodies with protection from disease progression is poorly understood. Here, we demonstrate that plasma IgA is a factor capable of modifying the magnitude of IgG-mediated ADCC in HIV infection, mitigating its beneficial effect. These results help in understanding why previous studies failed to demonstrate correlations between ADCC and disease progression, and they also contribute to the notion that an

  17. Pollen-Specific Aquaporins NIP4;1 and NIP4;2 Are Required for Pollen Development and Pollination in Arabidopsis thaliana.

    PubMed

    Di Giorgio, Juliana Andrea Pérez; Bienert, Gerd Patrick; Ayub, Nicolás Daniel; Yaneff, Agustín; Barberini, María Laura; Mecchia, Martín Alejandro; Amodeo, Gabriela; Soto, Gabriela Cynthia; Muschietti, Jorge Prometeo

    2016-05-01

    In flowers with dry stigmas, pollen development, pollination, and pollen tube growth require spatial and temporal regulation of water and nutrient transport. To better understand the molecular mechanisms involved in reproductive processes, we characterized NIP4;1 and NIP4;2, two pollen-specific aquaporins of Arabidopsis thaliana. NIP4;1 and NIP4;2 are paralogs found exclusively in the angiosperm lineage. Although they have 84% amino acid identity, they displayed different expression patterns. NIP4;1 has low expression levels in mature pollen, while NIP4;2 expression peaks during pollen tube growth. Additionally, NIP4;1pro:GUS flowers showed GUS activity in mature pollen and pollen tubes, whereas NIP4;2pro:GUS flowers only in pollen tubes. Single T-DNA mutants and double artificial microRNA knockdowns had fewer seeds per silique and reduced pollen germination and pollen tube length. Transport assays in oocytes showed NIP4;1 and NIP4;2 function as water and nonionic channels. We also found that NIP4;1 and NIP4;2 C termini are phosphorylated by a pollen-specific CPK that modifies their water permeability. Survival assays in yeast indicated that NIP4;1 also transports ammonia, urea, boric acid, and H2O2 Thus, we propose that aquaporins NIP4;1 and NIP4;2 are exclusive components of the reproductive apparatus of angiosperms with partially redundant roles in pollen development and pollination. PMID:27095837

  18. Secretory IgA specific for herpes simplex virus in lacrimal fluid from patients with herpes keratitis--a possible diagnostic parameter.

    PubMed Central

    Pedersen, B; Møller Andersen, S; Klauber, A; Ottovay, E; Prause, J U; Zhong, C U; Norrild, B

    1982-01-01

    In the present study a solid-phase radioimmune assay was used for the demonstration of herpes simplex virus-specific IgG and secretory IgA antibodies in the lacrimal fluid from patients with active recurrent herpes keratitis. The method was quantitative and made it possible to test specifically for the production of secretory IgA antibodies produced during an active herpes simplex virus infection. The production of secretory IgA was followed in 2 patients with fresh recurrent lesions. The HSV-specific secretory IgA could be demonstrated during the first 10 days of infection, where the maximal concentration was reached 3-5 days after the first symptoms occurred. The secretory antibodies were locally produced, and it is shown for the first time that herpes virus-specific secretory antibodies were of diagnostic value. PMID:6288066

  19. Vaccine-induced plasma IgA specific for the C1 region of the HIV-1 envelope blocks binding and effector function of IgG

    PubMed Central

    Tomaras, Georgia D.; Ferrari, Guido; Shen, Xiaoying; Alam, S. Munir; Liao, Hua-Xin; Pollara, Justin; Bonsignori, Mattia; Moody, M. Anthony; Fong, Youyi; Chen, Xi; Poling, Brigid; Nicholson, Cindo O.; Zhang, Ruijun; Lu, Xiaozhi; Parks, Robert; Kaewkungwal, Jaranit; Nitayaphan, Sorachai; Pitisuttithum, Punnee; Rerks-Ngarm, Supachai; Gilbert, Peter B.; Kim, Jerome H.; Michael, Nelson L.; Montefiori, David C.; Haynes, Barton F.

    2013-01-01

    Analysis of correlates of risk of infection in the RV144 HIV-1 vaccine efficacy trial demonstrated that plasma IgG against the HIV-1 envelope (Env) variable region 1 and 2 inversely correlated with risk, whereas HIV-1 Env-specific plasma IgA responses directly correlated with risk. In the secondary analysis, antibody-dependent cellular cytotoxicity (ADCC) was another inverse correlate of risk, but only in the presence of low plasma IgA Env-specific antibodies. Thus, we investigated the hypothesis that IgA could attenuate the protective effect of IgG responses through competition for the same Env binding sites. We report that Env-specific plasma IgA/IgG ratios are higher in infected than in uninfected vaccine recipients in RV144. Moreover, Env-specific IgA antibodies from RV144 vaccinees blocked the binding of ADCC-mediating mAb to HIV-1 Env glycoprotein 120 (gp120). An Env-specific monomeric IgA mAb isolated from an RV144 vaccinee also inhibited the ability of natural killer cells to kill HIV-1–infected CD4+ T cells coated with RV144-induced IgG antibodies. We show that monomeric Env-specific IgA, as part of postvaccination polyclonal antibody response, may modulate vaccine-induced immunity by diminishing ADCC effector function. PMID:23661056

  20. Pex1, a pollen-specific gene with an extensin-like domain.

    PubMed

    Rubinstein, A L; Broadwater, A H; Lowrey, K B; Bedinger, P A

    1995-04-11

    We report here the identification of a pollen-specific gene from Zea mays that contains multiple Ser-(Pro)n repeats, the motif found in the cell wall-associated extensins. Sequence analysis reveals that the encoded protein has a putative globular domain at the N terminus and an extensin-like domain at the C terminus. The Pex1 (pollen extensin-like) gene is expressed exclusively in pollen, not in vegetative or female tissues, and is not induced in leaves upon wounding. We propose that the encoded protein may have a role in reproduction, either as a structural element deposited in the pollen tube wall during its rapid growth or as a sexual recognition molecule that interacts with partner molecules in the pistil. PMID:7724520

  1. Region-specific sensitivity of anemophilous pollen deposition to temperature and precipitation.

    PubMed

    Donders, Timme H; Hagemans, Kimberley; Dekker, Stefan C; de Weger, Letty A; de Klerk, Pim; Wagner-Cremer, Friederike

    2014-01-01

    Understanding relations between climate and pollen production is important for several societal and ecological challenges, importantly pollen forecasting for pollinosis treatment, forensic studies, global change biology, and high-resolution palaeoecological studies of past vegetation and climate fluctuations. For these purposes, we investigate the role of climate variables on annual-scale variations in pollen influx, test the regional consistency of observed patterns, and evaluate the potential to reconstruct high-frequency signals from sediment archives. A 43-year pollen-trap record from the Netherlands is used to investigate relations between annual pollen influx, climate variables (monthly and seasonal temperature and precipitation values), and the North Atlantic Oscillation climate index. Spearman rank correlation analysis shows that specifically in Alnus, Betula, Corylus, Fraxinus, Quercus and Plantago both temperature in the year prior to (T-1), as well as in the growing season (T), are highly significant factors (TApril rs between 0.30 [P<0.05[ and 0.58 [P<0.0001]; TJuli-1 rs between 0.32 [P<0.05[ and 0.56 [P<0.0001]) in the annual pollen influx of wind-pollinated plants. Total annual pollen prediction models based on multiple climate variables yield R2 between 0.38 and 0.62 (P<0.0001). The effect of precipitation is minimal. A second trapping station in the SE Netherlands, shows consistent trends and annual variability, suggesting the climate factors are regionally relevant. Summer temperature is thought to influence the formation of reproductive structures, while temperature during the flowering season influences pollen release. This study provides a first predictive model for seasonal pollen forecasting, and also aides forensic studies. Furthermore, variations in pollen accumulation rates from a sub-fossil peat deposit are comparable with the pollen trap data. This suggests that high frequency variability pollen records from natural archives reflect

  2. Region-Specific Sensitivity of Anemophilous Pollen Deposition to Temperature and Precipitation

    PubMed Central

    Donders, Timme H.; Hagemans, Kimberley; Dekker, Stefan C.; de Weger, Letty A.; de Klerk, Pim; Wagner-Cremer, Friederike

    2014-01-01

    Understanding relations between climate and pollen production is important for several societal and ecological challenges, importantly pollen forecasting for pollinosis treatment, forensic studies, global change biology, and high-resolution palaeoecological studies of past vegetation and climate fluctuations. For these purposes, we investigate the role of climate variables on annual-scale variations in pollen influx, test the regional consistency of observed patterns, and evaluate the potential to reconstruct high-frequency signals from sediment archives. A 43-year pollen-trap record from the Netherlands is used to investigate relations between annual pollen influx, climate variables (monthly and seasonal temperature and precipitation values), and the North Atlantic Oscillation climate index. Spearman rank correlation analysis shows that specifically in Alnus, Betula, Corylus, Fraxinus, Quercus and Plantago both temperature in the year prior to (T-1), as well as in the growing season (T), are highly significant factors (TApril rs between 0.30 [P<0.05[ and 0.58 [P<0.0001]; TJuli-1 rs between 0.32 [P<0.05[ and 0.56 [P<0.0001]) in the annual pollen influx of wind-pollinated plants. Total annual pollen prediction models based on multiple climate variables yield R2 between 0.38 and 0.62 (P<0.0001). The effect of precipitation is minimal. A second trapping station in the SE Netherlands, shows consistent trends and annual variability, suggesting the climate factors are regionally relevant. Summer temperature is thought to influence the formation of reproductive structures, while temperature during the flowering season influences pollen release. This study provides a first predictive model for seasonal pollen forecasting, and also aides forensic studies. Furthermore, variations in pollen accumulation rates from a sub-fossil peat deposit are comparable with the pollen trap data. This suggests that high frequency variability pollen records from natural archives reflect

  3. The generation and evaluation of recombinant human IgA specific for Plasmodium falciparum merozoite surface protein 1-19 (PfMSP119)

    PubMed Central

    2011-01-01

    Background Human immunoglobulin G (IgG) plays an important role in mediating protective immune responses to malaria. Although human serum immunoglobulin A (IgA) is the second most abundant class of antibody in the circulation, its contribution, if any, to protective responses against malaria is not clear. Results To explore the mechanism(s) by which IgA may mediate a protective effect, we generated fully human IgA specific for the C-terminal 19-kDa region of Plasmodium falciparum merozoite surface protein 1 (PfMSP119), a major target of protective immune responses. This novel human IgA bound antigen with an affinity comparable to that seen for an epitope-matched protective human IgG1. Furthermore, the human IgA induced significantly higher NADPH-mediated oxidative bursts and degranulation from human neutrophils than the epitope-matched human IgG1 from which it was derived. Despite showing efficacy in in vitro functional assays, the human IgA failed to protect against parasite challenge in vivo in mice transgenic for the human Fcα receptor (FcαRI/CD89). A minority of the animals treated with IgA, irrespective of FcαRI expression, showed elevated serum TNF-α levels and concomitant mouse anti-human antibody (MAHA) responses. Conclusions The lack of protection afforded by MSP119-specific IgA against parasite challenge in mice transgenic for human FcαRI suggests that this antibody class does not play a major role in control of infection. However, we cannot exclude the possibility that protective capacity may have been compromised in this model due to rapid clearance and inappropriate bio-distribution of IgA, and differences in FcαRI expression profile between humans and transgenic mice. PMID:21781305

  4. Effect of Pollen-Specific Sublingual Immunotherapy on Oral Allergy Syndrome: An Observational Study

    PubMed Central

    2008-01-01

    Background Oral allergy syndrome (OAS) triggered by fruit and vegetables often occurs in patients with pollen-induced rhinoconjunctivitis because of cross-reactive epitopes in pollen and associated foods. This open observational study examined the effect of pollen-specific sublingual immunotherapy ([SLIT] B. U. Pangramin or SLITone involving birch/alder/hazel, grasses/rye, and/or mugwort) on OAS triggered by several foods in patients treated in standard practice. Very few studies have examined SLIT use in this situation. Methods Patients (n = 102) had pollen-induced rhinoconjunctivitis and OAS and were followed for up to 12 months. Baseline OAS (triggers, symptoms, and symptom severity) was assessed by questionnaire and patient history. Change in OAS was assessed using oral challenge test with 1 or 2 dominant food triggers (and compared with the sum score calculated from the OAS questionnaire at baseline) and clinician ratings of change. Pollen-induced rhinoconjunctivitis symptoms and medication use were also measured. Results In the oral challenge test, 77.0% of patients were considered responders (decrease in sum score of ≥ 50%; no difference in patients receiving B. U. Pangramin or SLITone). At baseline, investigators rated OAS severity as at least moderate in 94.9% of patients compared with 36.9% after 12 months of treatment. After 12 months, OAS was rated as much or very much improved in 72.9% of patients. Sublingual immunotherapy significantly reduced rhinoconjunctivitis symptoms and medication use. Only 10% of patients experienced adverse drug reactions. Conclusion This study supplements the sparse literature on this topic and suggests that pollen-specific SLIT can reduce OAS triggered by pollen-associated foods in patients with pollen-induced rhinoconjunctivitis. PMID:23282323

  5. A pollen-specific novel calmodulin-binding protein with tetratricopeptide repeats

    NASA Technical Reports Server (NTRS)

    Safadi, F.; Reddy, V. S.; Reddy, A. S.

    2000-01-01

    Calcium is essential for pollen germination and pollen tube growth. A large body of information has established a link between elevation of cytosolic Ca(2+) at the pollen tube tip and its growth. Since the action of Ca(2+) is primarily mediated by Ca(2+)-binding proteins such as calmodulin (CaM), identification of CaM-binding proteins in pollen should provide insights into the mechanisms by which Ca(2+) regulates pollen germination and tube growth. In this study, a CaM-binding protein from maize pollen (maize pollen calmodulin-binding protein, MPCBP) was isolated in a protein-protein interaction-based screening using (35)S-labeled CaM as a probe. MPCBP has a molecular mass of about 72 kDa and contains three tetratricopeptide repeats (TPR) suggesting that it is a member of the TPR family of proteins. MPCBP protein shares a high sequence identity with two hypothetical TPR-containing proteins from Arabidopsis. Using gel overlay assays and CaM-Sepharose binding, we show that the bacterially expressed MPCBP binds to bovine CaM and three CaM isoforms from Arabidopsis in a Ca(2+)-dependent manner. To map the CaM-binding domain several truncated versions of the MPCBP were expressed in bacteria and tested for their ability to bind CaM. Based on these studies, the CaM-binding domain was mapped to an 18-amino acid stretch between the first and second TPR regions. Gel and fluorescence shift assays performed with CaM and a CaM-binding synthetic peptide further confirmed MPCBP binding to CaM. Western, Northern, and reverse transcriptase-polymerase chain reaction analysis have shown that MPCBP expression is specific to pollen. MPCBP was detected in both soluble and microsomal proteins. Immunoblots showed the presence of MPCBP in mature and germinating pollen. Pollen-specific expression of MPCBP, its CaM-binding properties, and the presence of TPR motifs suggest a role for this protein in Ca(2+)-regulated events during pollen germination and growth.

  6. Rapid Effects of a Protective O-Polysaccharide-Specific Monoclonal IgA on Vibrio cholerae Agglutination, Motility, and Surface Morphology

    PubMed Central

    Levinson, Kara J.; De Jesus, Magdia

    2015-01-01

    2D6 is a dimeric monoclonal immunoglobulin A (IgA) specific for the nonreducing terminal residue of Ogawa O-polysaccharide (OPS) of Vibrio cholerae. It was previously demonstrated that 2D6 IgA is sufficient to passively protect suckling mice from oral challenge with virulent V. cholerae O395. In this study, we sought to define the mechanism by which 2D6 IgA antibody protects the intestinal epithelium from V. cholerae infection. In a mouse ligated-ileal-loop assay, 2D6 IgA promoted V. cholerae agglutination in the intestinal lumen and limited the ability of the bacteria to associate with the epithelium, particularly within the crypt regions. In vitro fluorescence digital video microscopy analysis of antibody-treated V. cholerae in liquid medium revealed that 2D6 IgA not only induced the rapid (5- to 10-min) onset of agglutination but was an equally potent inhibitor of bacterial motility. Scanning electron microscopy showed that 2D6 IgA promoted flagellum-flagellum cross-linking, as well as flagellar entanglement with bacterial bodies, suggesting that motility arrest may be a consequence of flagellar tethering. However, monovalent 2D6 Fab fragments also inhibited V. cholerae motility, demonstrating that antibody-mediated agglutination and motility arrest are separate phenomena. While 2D6 IgA is neither bactericidal nor bacteriostatic, exposure of V. cholerae to 2D6 IgA (or Fab fragments) resulted in a 5-fold increase in surface-associated blebs, as well an onset of a wrinkled surface morphotype. We propose that the protective immunity conferred by 2D6 IgA is the result of multifactorial effects on V. cholerae, including agglutination, motility arrest, and possibly outer membrane stress. PMID:25667263

  7. Frequent Use of the IgA Isotype in Human B Cells Encoding Potent Norovirus-Specific Monoclonal Antibodies That Block HBGA Binding.

    PubMed

    Sapparapu, Gopal; Czakó, Rita; Alvarado, Gabriela; Shanker, Sreejesh; Prasad, B V Venkataram; Atmar, Robert L; Estes, Mary K; Crowe, James E

    2016-06-01

    Noroviruses (NoV) are the most common cause of non-bacterial acute gastroenteritis and cause local outbreaks of illness, especially in confined situations. Despite being identified four decades ago, the correlates of protection against norovirus gastroenteritis are still being elucidated. Recent studies have shown an association of protection with NoV-specific serum histo-blood group antigen-blocking antibody and with serum IgA in patients vaccinated with NoV VLPs. Here, we describe the isolation and characterization of human monoclonal IgG and IgA antibodies against a GI.I NoV, Norwalk virus (NV). A higher proportion of the IgA antibodies blocked NV VLP binding to glycans than did IgG antibodies. We generated isotype-switched variants of IgG and IgA antibodies to study the effects of the constant domain on blocking and binding activities. The IgA form of antibodies appears to be more potent than the IgG form in blocking norovirus binding to histo-blood group antigens. These studies suggest a unique role for IgA antibodies in protection from NoV infections by blocking attachment to cell receptors. PMID:27355511

  8. Frequent Use of the IgA Isotype in Human B Cells Encoding Potent Norovirus-Specific Monoclonal Antibodies That Block HBGA Binding

    PubMed Central

    Shanker, Sreejesh; Prasad, B. V. Venkataram; Atmar, Robert L.; Estes, Mary K.; Crowe, James E.

    2016-01-01

    Noroviruses (NoV) are the most common cause of non-bacterial acute gastroenteritis and cause local outbreaks of illness, especially in confined situations. Despite being identified four decades ago, the correlates of protection against norovirus gastroenteritis are still being elucidated. Recent studies have shown an association of protection with NoV-specific serum histo-blood group antigen-blocking antibody and with serum IgA in patients vaccinated with NoV VLPs. Here, we describe the isolation and characterization of human monoclonal IgG and IgA antibodies against a GI.I NoV, Norwalk virus (NV). A higher proportion of the IgA antibodies blocked NV VLP binding to glycans than did IgG antibodies. We generated isotype-switched variants of IgG and IgA antibodies to study the effects of the constant domain on blocking and binding activities. The IgA form of antibodies appears to be more potent than the IgG form in blocking norovirus binding to histo-blood group antigens. These studies suggest a unique role for IgA antibodies in protection from NoV infections by blocking attachment to cell receptors. PMID:27355511

  9. First Membrane Proximal External Region-Specific Anti-HIV1 Broadly Neutralizing Monoclonal IgA1 Presenting Short CDRH3 and Low Somatic Mutations.

    PubMed

    Benjelloun, Fahd; Oruc, Zeliha; Thielens, Nicole; Verrier, Bernard; Champier, Gael; Vincent, Nadine; Rochereau, Nicolas; Girard, Alexandre; Jospin, Fabienne; Chanut, Blandine; Genin, Christian; Cogné, Michel; Paul, Stephane

    2016-09-01

    Mucosal HIV-1-specific IgA have been described as being able to neutralize HIV-1 and to block viral transcytosis. In serum and saliva, the anti-HIV IgA response is predominantly raised against the envelope of HIV-1. In this work, we describe the in vivo generation of gp41-specific IgA1 in humanized α1KI mice to produce chimeric IgA1. Mice were immunized with a conformational immunogenic gp41-transfected cell line. Among 2300 clones screened by immunofluorescence microscopy, six different gp41-specific IgA with strong recognition of gp41 were identified. Two of them have strong neutralizing activity against primary HIV-1 tier 1, 2, and 3 strains and present a low rate of somatic mutations and autoreactivity, unlike what was described for classical gp41-specific IgG. Epitopes were identified and located in the hepted repeat 2/membrane proximal external region. These Abs could be of interest in prophylactic treatment to block HIV-1 penetration in mucosa or in chronically infected patients in combination with antiretroviral therapy to reduce viral load and reservoir. PMID:27481846

  10. Bee Pollen

    MedlinePlus

    ... Don’t confuse bee pollen with bee venom, honey, or royal jelly. People take bee pollen for ... Pollen, Extrait de Pollen d’Abeille, Honeybee Pollen, Honey Bee Pollen, Maize Pollen, Pine Pollen, Polen de ...

  11. Association of HIV-1 Envelope-Specific Breast Milk IgA Responses with Reduced Risk of Postnatal Mother-to-Child Transmission of HIV-1

    PubMed Central

    Pollara, Justin; McGuire, Erin; Fouda, Genevieve G.; Rountree, Wes; Eudailey, Josh; Overman, R. Glenn; Seaton, Kelly E.; Deal, Aaron; Edwards, R. Whitney; Tegha, Gerald; Kamwendo, Deborah; Kumwenda, Jacob; Nelson, Julie A. E.; Liao, Hua-Xin; Brinkley, Christie; Denny, Thomas N.; Ochsenbauer, Christina; Ellington, Sascha; King, Caroline C.; Jamieson, Denise J.; van der Horst, Charles; Kourtis, Athena P.; Tomaras, Georgia D.; Ferrari, Guido

    2015-01-01

    ABSTRACT Infants born to HIV-1-infected mothers in resource-limited areas where replacement feeding is unsafe and impractical are repeatedly exposed to HIV-1 throughout breastfeeding. Despite this, the majority of infants do not contract HIV-1 postnatally, even in the absence of maternal antiretroviral therapy. This suggests that immune factors in breast milk of HIV-1-infected mothers help to limit vertical transmission. We compared the HIV-1 envelope-specific breast milk and plasma antibody responses of clade C HIV-1-infected postnatally transmitting and nontransmitting mothers in the control arm of the Malawi-based Breastfeeding Antiretrovirals and Nutrition Study using multivariable logistic regression modeling. We found no association between milk or plasma neutralization activity, antibody-dependent cell-mediated cytotoxicity, or HIV-1 envelope-specific IgG responses and postnatal transmission risk. While the envelope-specific breast milk and plasma IgA responses also did not reach significance in predicting postnatal transmission risk in the primary model after correction for multiple comparisons, subsequent exploratory analysis using two distinct assay methodologies demonstrated that the magnitudes of breast milk total and secretory IgA responses against a consensus HIV-1 envelope gp140 (B.con env03) were associated with reduced postnatal transmission risk. These results suggest a protective role for mucosal HIV-1 envelope-specific IgA responses in the context of postnatal virus transmission. This finding supports further investigations into the mechanisms by which mucosal IgA reduces risk of HIV-1 transmission via breast milk and into immune interventions aimed at enhancing this response. IMPORTANCE Infants born to HIV-1-infected mothers are repeatedly exposed to the virus in breast milk. Remarkably, the transmission rate is low, suggesting that immune factors in the breast milk of HIV-1-infected mothers help to limit transmission. We compared the antibody

  12. High correlation of specific IgE sensitization between birch pollen, soy and apple allergens indicates pollen-food allergy syndrome among birch pollen allergic patients in northern China

    PubMed Central

    Hao, Guo-dong; Zheng, Yi-wu; Wang, Zhi-xiang; Kong, Xing-ai; Song, Zhi-jing; Lai, Xu-xin; Spangfort, Michael D.

    2016-01-01

    Background: Birch pollen sensitization and associated pollen-food syndrome among Chinese allergic patients have not been investigated. Methods: Sera from 203 allergic patients from the northern part of China and collected during February to July 2014 were investigated. Specific immunoglobulin E (IgE) against birch pollen extract Bet v and major birch pollen allergen Bet v 1 were measured using the ADVIA Centaur. The presence of major apple allergen Mal d 1 and soy bean allergen Gly m 4 specific IgE was measured by ImmunoCAP 100. Results: Among the 203 sera, 34 sera (16.7%) had specific IgE to Bet v and of these, 28 sera (82.4%) contained Bet v 1-specific IgE. Among the 28 sera with Bet v 1-specific IgE, 27 sera (96.4%) contained Mal d 1-specific IgE and 22 sera (78.6%) contained Gly m 4-specific IgE. Of the 34 Bet v-positive sera, 6 sera (17.6%) contained no specific IgE for Bet v 1, Mal d 1, or Gly m 4. Almost all Bet v-positive sera were donated during the birch pollen season. Conclusions: The prevalence of birch allergy among patients visiting health care during pollen season can be as high as 16.7% in Tangshan City. The majority of Chinese birch allergic patients are IgE-sensitized to the major birch pollen allergen Bet v 1 as well as to the major apple allergen Mal d 1 and soy bean allergen Gly m 4. A relatively high number of patients (17.6%) are IgE-sensitized to birch pollen allergen(s) other than Bet v 1. The high prevalence of specific IgE to Mal d 1 and Gly m 4 among Bet v 1-sensitized patients indicates that pollen-food allergy syndrome could be of clinical relevance in China. PMID:27143268

  13. Specific immunotherapy with mugwort pollen allergoid reduce bradykinin release into the nasal fluid

    PubMed Central

    Grzanka, Alicja; Jawor, Barbara; Czecior, Eugeniusz

    2016-01-01

    Introduction A pathomechanism of allergic rhinitis is complex. A neurogenic mechanism seems to play a significant role in this phenomenon. Aim The evaluation of influence of specific immunotherapy of mugwort pollen allergic patients on the bradykinin concentration in the nasal lavage fluid. Material and methods The study included 22 seasonal allergic rhinitis patients. Thirty persons with monovalent allergy to mugwort pollen, confirmed with skin prick tests and allergen-specific immunoglobulin E, underwent a 3-year-long allergen immunotherapy with the mugwort extract (Allergovit, Allergopharma, Germany). The control group was composed of 9 persons with polyvalent sensitivity to pollen, who were treated with pharmacotherapy. Before the allergen-specific immunotherapy (AIT) and in subsequent years before the pollen seasons, a provocation allergen test with the mugwort extract was performed, together with collection of nasal fluids, where bradykinin concentration was determined according to Proud method. Results There were similar levels of bradykinin in both groups at baseline prior to therapy (AIT group: 584.0 ±87.2 vs. controls 606.3 ±106.5 pg/ml) and changes after allergen challenge 1112.4 ±334.8 vs. 1013.3 ±305.9 pg/ml as well. The bradykinin concentration in nasal lavage fluid after mugwort challenge in 1 year was lower in the AIT group (824.1 ±184.2 pg/ml vs. 1000.4 ±411.5 pg/l; p < 005) with a further significant decrease after the 2nd and 3rd year of specific immunotherapy. Significant reduction of symptoms and medications use was observed in hyposensitized patients. Conclusions A decreased level of bradykinin as a result of AIT suggests that some of the symptomatic benefits of AIT may be related to the reduced release of bradykinin into nasal secretions. These values correlate with clinical improvement within the course of treatment. PMID:27605897

  14. Specific pollen allergen activates eosinophils of the patient with chronic allergic contact urticaria.

    PubMed

    Panaszek, B; Małolepszy, J; Kuryszko, J; Litwa, M

    1994-01-01

    The aim of the study was to evaluate the activation of eosinophils in an unique case of a young man with atopy manifested as chronic pollen contact urticaria. In order to reveal the role of eosinophils in that case, the study was performed by means of monoclonal antibodies EG2 and chemiluminescence. In addition, comparative electron microscopic study of peripheral blood and skin infiltrating eosinophils were performed for which the name ultrastructural morphometric analysis of intracytoplasmic eosinophil granules has been proposed. The results indicated, that 40% of peripheral blood eosinophils were activated spontaneously and they were more active than those in skin infiltrates. Specific pollen allergen caused activation of 100% of peripheral blood eosinophils. The study suggests presence of a systemic pattern of eosinophil activation in atopy. PMID:7487362

  15. The pollen-specific R-SNARE/longin PiVAMP726 mediates fusion of endo- and exocytic compartments in pollen tube tip growth.

    PubMed

    Guo, Feng; McCubbin, Andrew G

    2012-05-01

    The growing pollen tube apex is dedicated to balancing exo- and endocytic processes to form a rapidly extending tube. As perturbation of either tends to cause a morphological phenotype, this system provides tractable model for studying these processes. Vesicle-associated membrane protein 7s (VAMP7s) are members of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family that mediate cognate membrane fusion but their role in pollen tube growth has not been investigated. This manuscript identifies PiVAMP726 of Petunia inflata as a pollen-specific VAMP7 that localizes to the inverted cone of transport vesicles at the pollen tube tip. The endocytic marker FM4-64 was found to colocalize with yellow fluorescent protein (YFP)-PiVAMP726, which is consistent with PiVAMP726 containing an amino-acid motif implicated in endosomal localization, At high overexpression levels, YFP- PiVAMP726 inhibited growth and caused the formation of novel membrane compartments within the pollen tube tip. Functional dissection of PiVAMP726 implicated the N-terminal longin domain in negative regulation of the SNARE activity, but not localization of PiVAMP726. Expression of the constitutively active C-terminal SNARE domain alone, in pollen tubes, generated similar phenotypes to the full-length protein, but the truncated domain was more potent than the wild-type protein at both inhibiting growth and forming the novel membrane compartments. Both endo- and exocytic markers localized to these compartments in addition to YFP-PiVAMP726, leading to the speculation that PiVAMP726 might be involved in the recycling of endocytic vesicles in tip growth. PMID:22345643

  16. Periodontal Disease Bacteria Specific to Tonsil in IgA Nephropathy Patients Predicts the Remission by the Treatment

    PubMed Central

    Date, Yasuhiro; Iwatani, Hirotsugu; Yamamoto, Ryohei; Horii, Arata; Inohara, Hidenori; Imai, Enyu; Nakanishi, Takeshi; Ohno, Hiroshi; Rakugi, Hiromi; Isaka, Yoshitaka

    2014-01-01

    Background Immunoglobulin (Ig)A nephropathy (IgAN) is the most common form of primary glomerulonephritis in the world. Some bacteria were reported to be the candidate of the antigen or the pathogenesis of IgAN, but systematic analysis of bacterial flora in tonsil with IgAN has not been reported. Moreover, these bacteria specific to IgAN might be candidate for the indicator which can predict the remission of IgAN treated by the combination of tonsillectomy and steroid pulse. Methods and Findings We made a comprehensive analysis of tonsil flora in 68 IgAN patients and 28 control patients using Denaturing gradient gel electrophoresis methods. We also analyzed the relationship between several bacteria specific to the IgAN and the prognosis of the IgAN. Treponema sp. were identified in 24% IgAN patients, while in 7% control patients (P = 0.062). Haemophilus segnis were detected in 53% IgAN patients, while in 25% control patients (P = 0.012). Campylobacter rectus were identified in 49% IgAN patients, while in 14% control patients (P = 0.002). Multiple Cox proportional-hazards model revealed that Treponema sp. or Campylobactor rectus are significant for the remission of proteinuria (Hazard ratio 2.35, p = 0.019). There was significant difference in remission rates between IgAN patients with Treponema sp. and those without the bacterium (p = 0.046), and in remission rates between IgAN patients with Campylobacter rectus and those without the bacterium (p = 0.037) by Kaplan-Meier analysis. Those bacteria are well known to be related with the periodontal disease. Periodontal bacteria has known to cause immune reaction and many diseases, and also might cause IgA nephropathy. Conclusion This insight into IgAN might be useful for diagnosis of the IgAN patients and the decision of treatment of IgAN. PMID:24489644

  17. Serological diagnosis of pertussis: evaluation of IgA against whole cell and specific Bordetella pertussis antigens as markers of recent infection.

    PubMed Central

    Poynten, M.; Hanlon, M.; Irwig, L.; Gilbert, G. L.

    2002-01-01

    In Australia, notification of pertussis cases in older children or adults has increased significantly in recent years. In most cases, laboratory diagnosis is based only on a positive serological test for IgA antibody against whole cell Bordetella pertussis. During a 3-month period, 318 consecutive sera submitted for diagnosis of pertussis were tested for IgA antibody against whole cell (WC) sonicated B. pertussis, pertussis toxin (PT), filamentous haemagglutinin (FHA) and pertactin (PRN). Results of one or more of these tests were positive in sera from 175 subjects and clinical information was obtained by telephone interview from 90 subjects. Using a clinical case definition as the reference standard, the sensitivities of the four IgA assays were variable but quite low (24-64%), but the specificities were high (93-98%). For diagnosis of pertussis in subjects with a compatible clinical illness, these and other findings support the use of serological testing for IgA antibody. PMID:12002533

  18. Possible therapeutic potential of a recombinant group 2 grass pollen allergen-specific antibody fragment.

    PubMed

    Gadermaier, E; Flicker, S; Blatt, K; Valent, P; Valenta, R

    2014-02-01

    The induction of blocking IgG antibodies that compete with IgE for allergen binding is one important mechanism of allergen-specific immunotherapy. The application of blocking antibodies may be an alternative treatment strategy. A synthetic gene coding for a single-chain fragment (ScFv) specific for the major timothy grass pollen allergen Phl p 2 was inserted into plasmid pCANTAB 5 E, and the recombinant ScFv was expressed in Escherichia coli and purified by affinity chromatography. The ScFv was tested for allergen binding by ELISA, and its association and dissociation were measured by surface plasmon resonance (Biacore) technology. The ability of the ScFv to inhibit allergic patients' IgE binding to Phl p 2 and Phl p 2-induced basophil degranulation was studied by ELISA competition and basophil activation (CD203c) assays. We report the expression, purification, biochemical and immunological characterization of a monomeric single-chain fragment (ScFv) of human origin specific for the major timothy grass pollen allergen, Phl p 2. The Phl p 2-ScFv showed high affinity binding to the allergen and blocked the binding of allergic patients' polyclonal IgE to Phl p 2 up to 98%. Furthermore, it inhibited allergen-induced basophil activation. The Phl p 2-ScFv inhibited allergic patients' IgE binding to Phl p 2 as well as Phl p 2-induced basophil activation and might be useful for passive immunotherapy of grass pollen allergy. PMID:24251384

  19. Detection of Specific IgA Antibodies against a Novel Deamidated 8-Mer Gliadin Peptide in Blood Plasma Samples from Celiac Patients

    PubMed Central

    Vallejo-Diez, Sara; Bernardo, David; Moreno, María de Lourdes; Muñoz-Suano, Alba; Fernández-Salazar, Luis; Calvo, Carmen; Sousa, Carolina; Garrote, José A.; Cebolla, Ángel; Arranz, Eduardo

    2013-01-01

    We studied whether celiac disease (CD) patients produce antibodies against a novel gliadin peptide specifically generated in the duodenum of CD patients by a previously described pattern of CD-specific duodenal proteases. Fingerprinting and ion-trap mass spectrometry of CD-specific duodenal gliadin-degrading protease pattern revealed a new 8-mer gliadin-derived peptide. An ELISA against synthetic deamidated 8-mer peptides (DGP 8-mer) was used to study the presence of IgA anti-DGP 8-mer antibodies in plasma samples from 81 children (31 active CD patients (aCD), 17 CD patients on a gluten-free diet (GFD), 10 healthy controls (C) and 23 patients with other gastrointestinal pathology (GP)) and 101 adults (16 aCD, 12 GFD, 27 C and 46 GP-patients). Deamidation of the 8-mer peptide significantly increased the reactivity of the IgA antibodies from CD patients against the peptide. Significant IgA anti-DGP 8-mer antibodies levels were detected in 93.5% of aCD-, 11.8% of GFD- and 4.3% of GP-patients in children. In adults, antibodies were detected in 81.3% of aCD-patients and 8.3% of GFD-patients while were absent in 100% of C- and GP-patients. Duodenal CD-specific gliadin degrading proteases release an 8-mer gliadin peptide that once deamidated is an antigen for specific IgA antibodies in CD patients which may provide a new accurate diagnostic tool in CD. PMID:24278359

  20. Determination of allergen specificity by heavy chains in grass pollen allergen–specific IgE antibodies

    PubMed Central

    Gadermaier, Elisabeth; Flicker, Sabine; Lupinek, Christian; Steinberger, Peter; Valenta, Rudolf

    2013-01-01

    Background Affinity and clonality of allergen-specific IgE antibodies are important determinants for the magnitude of IgE-mediated allergic inflammation. Objective We sought to analyze the contribution of heavy and light chains of human allergen-specific IgE antibodies for allergen specificity and to test whether promiscuous pairing of heavy and light chains with different allergen specificity allows binding and might affect affinity. Methods Ten IgE Fabs specific for 3 non–cross-reactive major timothy grass pollen allergens (Phl p 1, Phl p 2, and Phl p 5) obtained by means of combinatorial cloning from patients with grass pollen allergy were used to construct stable recombinant single chain variable fragments (ScFvs) representing the original Fabs and shuffled ScFvs in which heavy chains were recombined with light chains from IgE Fabs with specificity for other allergens by using the pCANTAB 5 E expression system. Possible ancestor genes for the heavy chain and light chain variable region–encoding genes were determined by using sequence comparison with the ImMunoGeneTics database, and their chromosomal locations were determined. Recombinant ScFvs were tested for allergen specificity and epitope recognition by means of direct and sandwich ELISA, and affinity by using surface plasmon resonance experiments. Results The shuffling experiments demonstrate that promiscuous pairing of heavy and light chains is possible and maintains allergen specificity, which is mainly determined by the heavy chains. ScFvs consisting of different heavy and light chains exhibited different affinities and even epitope specificity for the corresponding allergen. Conclusion Our results indicate that allergen specificity of allergen-specific IgE is mainly determined by the heavy chains. Different heavy and light chain pairings in allergen-specific IgE antibodies affect affinity and epitope specificity and thus might influence clinical reactivity to allergens. PMID:23206656

  1. Presence of IgA and IgG antigliadin antibodies in healthy adults as measured by micro-ELISA. Effect of various cutoff levels on specificity and sensitivity when diagnosing coeliac disease.

    PubMed

    Grodzinsky, E; Hed, J; Liedén, G; Sjögren, F; Ström, M

    1990-01-01

    In this study a micro-ELISA (ELISA = enzyme-linked immunosorbent assay) was established and used to evaluate IgA and IgG antigliadin antibodies in 1,866 healthy adults. There was a covariation between the level of IgA antigliadin antibodies and the total serum IgA concentration, probably due to an increased IgA response in some healthy subjects. We could not find any correlation between the presence of IgG and IgA antibodies in the healthy population using the 97.5th percentile as a cutoff value. The specificity of various cutoff levels was compared with the sensitivity of the test in a population of 40 patients with coeliac disease. IgA antigliadin antibodies had a high specificity (95%) at a cutoff value giving a high sensitivity (80%). This was not possible with IgG antigliadin antibodies which had a low sensitivity (40%) when the cutoff value was selected to give a high specificity. Due to the low prevalence of coeliac disease, a decrease in the specificity of the test will have a pronounced effect on the positive predictive value. The results indicate that only IgA antigliadin antibodies are useful markers when screening subjects with few typical symptoms for biopsy when diagnosing coeliac disease, whereas IgG antibodies are of low value because of their low specificity. PMID:2242925

  2. Detection of systemic and mucosal HPV-specific IgG and IgA antibodies in adolescent girls one and two years after HPV vaccination

    PubMed Central

    Scherpenisse, Mirte; Mollers, Madelief; Schepp, Rutger M.; Meijer, Chris J.L.M.; de Melker, Hester E.; Berbers, Guy A.M.; van der Klis, Fiona R.M.

    2013-01-01

    The bivalent HPV16/18 vaccine induces high antibody concentrations in serum while data about antibody responses in the cervix are limited. In this study, we investigated pre- and post-vaccination antibody responses against seven high-risk HPV types by detection of IgG and IgA HPV-specific antibodies in cervical secretion samples (CVS) and serum. From an HPV vaccine monitoring study CVS and serum samples were available (pre-vaccination (n = 297), one year (n = 211) and two years (n = 141) post-dose-one vaccination) from girls aged 14–16 y. The girls were vaccinated with the bivalent HPV vaccine at months 0, 1 and 6. CVS was self-sampled using a tampon. Samples were tested for HPV-specific antibodies (HPV16/18/31/33/45/52/58) by a VLP-based multiplex immunoassay. Post-vaccination, IgG and IgA antibody levels for HPV16/18 were detectable in CVS and amounted to 2% and 1% of the IgG and IgA antibody levels observed in serum, respectively. The antibody levels remained constant between one and two years after vaccination. The correlation between CVS and serum was similar for IgG and IgA vaccine-derived antibody levels for HPV16 (rs = 0.58, rs = 0.54) and HPV18 (rs = 0.50, rs = 0.55). Vaccine-derived IgG antibody levels against cross-reactive HPV types in CVS and in serum were highest for HPV45. No IgA cross-reactive antibody responses could be detected in CVS. Post-vaccination, HPV16/18 IgG and IgA antibodies are not only detectable in serum but also in CVS. The correlation of HPV16/18 IgG antibody levels between serum and CVS suggests that vaccine induced HPV antibodies transudate and/or exudate from the systemic circulation to the cervical mucosa to provide protection against HPV infections. PMID:23149693

  3. Hypervariable Domains of Self-Incompatibility RNases Mediate Allele-Specific Pollen Recognition.

    PubMed Central

    Matton, D. P.; Maes, O.; Laublin, G.; Xike, Q.; Bertrand, C.; Morse, D.; Cappadocia, M.

    1997-01-01

    Self-incompatibility (SI) in angiosperms is a genetic mechanism that promotes outcrossing through rejection of self-pollen. In the Solanaceae, SI is determined by a multiallelic S locus whose only known product is an S RNase. S RNases show a characteristic pattern of five conserved and two hypervariable regions. These are thought to be involved in the catalytic function and in allelic specificity, respectively. When the Solanum chacoense S12S14 genotype is transformed with an S11 RNase, the styles of plants expressing significant levels of the transgene reject S11 pollen. A previously characterized S RNase, S13, differs from the S11 RNase by only 10 amino acids, four of which are located in the hypervariable regions. When S12S14 plants were transformed with a chimeric S11 gene in which these four residues were substituted with those present in the S13 RNase, the transgenic plants acquired the S13 phenotype. This result demonstrates that the S RNase hypervariable regions control allelic specificity. PMID:12237346

  4. Specific allergen immunotherapy attenuates allergic airway inflammation in a rat model of Alstonia scholaris pollen induced airway allergy.

    PubMed

    Datta, Ankur; Moitra, Saibal; Hazra, Iman; Mondal, Somnath; Das, Prasanta Kumar; Singh, Manoj Kumar; Chaudhuri, Suhnrita; Bhattacharya, Debanjan; Tripathi, Santanu Kumar; Chaudhuri, Swapna

    2016-01-01

    Pollen grains are well established to be an important cause of respiratory allergy. Current pharmacologic therapies for allergic asthma do not cure the disease. Allergen specific immunotherapy is the only treatment method which re-directs the immune system away from allergic response leading to a long lasting effect. The mechanism by which immunotherapy achieves this goal is an area of active research world-wide. The present experimental study was designed to develop an experimental model of allergic lung inflammation based on a relevant human allergen, Alstonia scholaris pollen, and to establish the immunological and cellular features of specific allergen immunotherapy using this same pollen extract. Our results revealed that Alstonia scholaris pollen sensitization and challenge causes eosinophilic airway inflammation with mucin hypersecretion. This is associated with increased total IgE, increased expression of FcɛRI on lung mast cells and increased levels of IL-4, IL-5 & IL-13 as confirmed by ELISA, in-situ immunofluorescence and FACS assay. Allergen specific immunotherapy reduced airway inflammation and also decreased total IgE level, FcɛRI expression, IL-4, IL-5 & IL-13 levels. It was further noted that the reduction of these levels was more by intra-nasal route than by intra-peritoneal route. Thus we present a novel animal model of Alstonia scholaris pollen allergic disease and specific allergen immunotherapy which will pave the way towards the development of better treatment modalities. PMID:26667977

  5. Measurement of Chlamydia pneumoniae-Specific Immunoglobulin A (IgA) Antibodies by the Microimmunofluorescence (MIF) Method: Comparison of Seven Fluorescein-Labeled Anti-Human IgA Conjugates in an In-House MIF Test Using One Commercial MIF and One Enzyme Immunoassay Kit

    PubMed Central

    Paldanius, Mika; Bloigu, Aini; Leinonen, Maija; Saikku, Pekka

    2003-01-01

    For the serological diagnosis of acute Chlamydia pneumoniae infection, the microimmunofluorescence (MIF) test is the most commonly used method and also the “gold standard” for the measurement of immunoglobulin G (IgG) and IgM antibodies. The role of IgA antibodies in diagnosis has not been established. Commercially available fluorescein-labeled anti-human IgA conjugates have not been systematically compared to each other, and this situation may cause considerable variations in IgA results. Therefore, we tested 261 serum samples from 122 patients with pneumonia for IgA antibodies by using six α-chain-specific anti-IgA conjugates in our in-house MIF test, one commercial MIF test, and one enzyme immunoassay (EIA). Interfering IgG antibodies were removed with Gullsorb reagent before the measurement of IgA antibodies. Altogether, 14 significant IgA antibody increases in serum samples between the acute phase and the convalescent phase were detected by at least one of the conjugates in the MIF test, while no increases were found in the IgA EIA. Only one patient showed a significant IgA antibody increase with all of the fluorescein-labeled conjugates. Five significant titer changes were detected by at least two conjugates, and in nine instances, the titer increase was detected by one conjugate only. The titer agreement indicated by kappa coefficients was very good or good for all of the fluorescein-labeled conjugates and the EIA with low antibody titers but decreased with increasing titers. PMID:12522032

  6. Cross-reactivity among non-specific lipid-transfer proteins from food and pollen allergenic sources.

    PubMed

    Morales, María; López-Matas, M Ángeles; Moya, Raquel; Carnés, Jerónimo

    2014-12-15

    Non-specific lipid-transfer proteins (nsLTPs) are a family of pan-allergens present in foods and pollen. However, sequence homology among them is limited. The objective of this study was to evaluate the IgE-mediated cross-reactivity between nsLTPs from different sources and evaluate the allergenic properties of LTPs from peach (Pru p 3) and pellitory (Par j 1/Par j 2), major fruit and pollen allergens. Both proteins were purified and characterised. Cross-reactivity studies among nsLTPs from different foods and pollens were performed by immunoblot inhibition using sera specific to peach or pellitory pollen. Cross-reactivity with Pru p 3 was observed in hazelnut, onion, corn, peanut and apple while in pollens, none of the extracts was inhibited with Par j 1/2. In conclusion, Pru p 3 did not inhibit LTPs from most fruits. Therefore, although Pru p 3 covers the largest number of epitopes, diagnosis with only this allergen may not detect all LTP sensitivities. PMID:25038692

  7. Elevated Serum Transforming Growth Factor β1 Levels in Epstein-Barr Virus-Associated Diseases and Their Correlation with Virus-Specific Immunoglobulin A (IgA) and IgM

    PubMed Central

    Xu, Jingwu; Ahmad, Ali; Jones, James F.; Dolcetti, Riccardo; Vaccher, Emanuela; Prasad, Umapati; Menezes, José

    2000-01-01

    Transforming growth factor β (TGF-β) is an immunosuppressive cytokine which can induce immunoglobulin A (IgA) switch and Epstein-Barr virus (EBV) replication in latently infected cells. Here we report elevated serum levels of TGF-β in various EBV-associated diseases correlating positively with EBV-specific IgA titers and negatively with IgM titers, suggesting a role for this cytokine in the pathogenesis of these diseases. PMID:10666277

  8. Salivary IgA against sporozoite-specific embryogenesis-related protein (TgERP) in the study of horizontally transmitted toxoplasmosis via T. gondii oocysts in endemic settings.

    PubMed

    Mangiavacchi, B M; Vieira, F P; Bahia-Oliveira, L M G; Hill, D

    2016-09-01

    The aim of this study was to contribute to the better understanding of the relative epidemiological importance of different modes of infection with respect to horizontal transmission of Toxoplasma gondii in endemic settings. We investigated the prevalence of salivary IgA against a sporozoite-specific embryogenesis-related protein (TgERP) in a highly endemic area for toxoplasmosis in Brazil in order to pinpoint parasite transmission via oocysts. Prevalence calculated by salivary IgA specific to TgERP was compared to the prevalence calculated by serum IgG against both TgERP and tachyzoites (in conventional serological tests). Prevalence calculated by different serological and salivary parameters varied in the studied age groups. However, for the 15-21 years age group, values for T. gondii prevalence estimated by conventional serological tests and by anti-TgERP salivary IgA were similar; i.e. 68·7% and 66·6% or 66·7%, respectively, using two different cut-off parameters for salivary IgA anti-TgERP. Furthermore, salivary IgA anti-TgERP for this age group presented the highest specificity (93·33%), sensitivity (93·94%), and likelihood (14·09) compared to all the other age groups. These data demonstrate the importance of age for salivary IgA investigation against TgERP to estimate the mode of T. gondii transmission in endemic settings. PMID:27169485

  9. STIL, a peculiar molecule from styles, specifically dephosphorylates the pollen receptor kinase LePRK2 and stimulates pollen tube growth in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: LePRK1 and LePRK2 are two pollen receptor kinases localized to the plasma membrane, where they are present in a high molecular weight complex (LePRK complex). LePRK2 is phosphorylated in mature and germinated pollen, but is dephosphorylated when pollen membranes are incubated with tomato...

  10. A distinct mechanism regulating a pollen-specific guanine nucleotide exchange factor for the small GTPase Rop in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rop/Rac small GTPases are central to diverse developmental and cellular activities in plants, playing an especially important role in polar growth of pollen tubes. Although it is established that a class of plant-specific RopGEFs promotes the activity of Rop/Rac through the catalytic PRONE (Plant sp...

  11. Specificity of hydrolysis of phytic acid by alkaline phytase from lily pollen.

    PubMed Central

    Barrientos, L; Scott, J J; Murthy, P P

    1994-01-01

    Phytases are the primary enzymes responsible for the hydrolysis of phytic acid, myo-inositol-1,2,3,4,5,6-hexakisphosphate (I-1,2,3,4,5,6-P6). A number of phytases with varying specificities, properties, and localizations hydrolyze phytic acid present in cells. The specificity of hydrolysis of phytic acid by alkaline phytase from lily (Lilium longiflorum L.) pollen is described. Structures of the intermediate inositol phosphates and the final product were established by a variety of nuclear magnetic resonance techniques (1H-, 31P-, and 31P-1H-detected multiple quantum coherence spectroscopy, and total correlation spectroscopy). On the basis of the structures identified we have proposed a scheme of hydrolysis of phytic acid. Initial hydrolysis of the phosphate ester occurs at the D-5 position of phytic acid to yield the symmetrical I-1,2,3,4,6-P5. The two subsequent dephosphorylations occur adjacent to the D-5 hydroxyl group to yield I-1,2,3-P3 as the final product. Alkaline phytase differs from other phytases in the specificity of hydrolysis of phosphate esters on the inositol ring, its high substrate specificity for phytic acid, and biochemical properties such as susceptibility to activation by calcium and inhibition by fluoride. The physiological significance of alkaline phytase and the biological role of I-1,2,3-P3 remain to be identified. PMID:7846160

  12. Down-Regulating CsHT1, a Cucumber Pollen-Specific Hexose Transporter, Inhibits Pollen Germination, Tube Growth, and Seed Development1[OPEN

    PubMed Central

    Cheng, Jintao; Wang, Zhenyu; Yao, Fengzhen; Gao, Lihong; Ma, Si; Zhang, Zhenxian

    2015-01-01

    Efficient sugar transport is needed to support the high metabolic activity of pollen tubes as they grow through the pistil. Failure of transport results in male sterility. Although sucrose transporters have been shown to play a role in pollen tube development, the role of hexoses and hexose transporters is not as well established. The pollen of some species can grow in vitro on hexose as well as on sucrose, but knockouts of individual hexose transporters have not been shown to impair fertilization, possibly due to transporter redundancy. Here, the functions of CsHT1, a hexose transporter from cucumber (Cucumis sativus), are studied using a combination of heterologous expression in yeast (Saccharomyces cerevisiae), histochemical and immunohistochemical localization, and reverse genetics. The results indicate that CsHT1 is a plasma membrane-localized hexose transporter with high affinity for glucose, exclusively transcribed in pollen development and expressed both at the levels of transcription and translation during pollen grain germination and pollen tube growth. Overexpression of CsHT1 in cucumber pollen results in a higher pollen germination ratio and longer pollen tube growth than wild-type pollen in glucose- or galactose-containing medium. By contrast, antisense suppression of CsHT1 leads to inhibition of pollen germination and pollen tube elongation in the same medium and results in a decrease of seed number per fruit and seed size when antisense transgenic pollen is used to fertilize wild-type or transgenic cucumber plants. The important role of CsHT1 in pollen germination, pollen tube growth, and seed development is discussed. PMID:25888616

  13. Lack of cleavage of immunoglobulin A (IgA) from rhesus monkeys by bacterial IgA1 proteases.

    PubMed Central

    Reinholdt, J; Kilian, M

    1991-01-01

    Bacterial immunoglobulin A1 (IgA1) proteases cleaving IgA1 and secretory IgA1 molecules in the hinge region are believed to be important virulence factors. Previous studies have indicated that IgA of humans, gorillas, and chimpanzees are the exclusive substrates of these enzymes. In a recent study, IgA from the rhesus monkey was found to be susceptible to the IgA1 protease activity of Streptococcus pneumoniae. In an attempt to reproduce this observation, we found that neither five isolates of S. pneumoniae nor other IgA1 protease-producing bacteria representing different cleavage specificities caused cleavage of rhesus monkey IgA. Hence, the rhesus monkey does not appear to be a suitable animal model for studies of IgA1 proteases as virulence factors. Images PMID:2037384

  14. MIKC* MADS-Protein Complexes Bind Motifs Enriched in the Proximal Region of Late Pollen-Specific Arabidopsis Promoters[W

    PubMed Central

    Verelst, Wim; Saedler, Heinz; Münster, Thomas

    2007-01-01

    The genome of Arabidopsis (Arabidopsis thaliana) encodes over 100 MADS-domain transcription factors, categorized into five phylogenetic subgroups. Most research efforts have focused on just one of these subgroups (MIKCc), whereas the other four remain largely unexplored. Here, we report on five members of the so-called Mδ or Arabidopsis MIKC* (AtMIKC*) subgroup, which are predominantly expressed during the late stages of pollen development. Very few MADS-box genes function in mature pollen, and from this perspective, the AtMIKC* genes are therefore highly exceptional. We found that the AtMIKC* proteins are able to form multiple heterodimeric complexes in planta, and that these protein complexes exhibit a for the MADS-family unusual and high DNA binding specificity in vitro. Compared to their occurrence in promoters genome wide, AtMIKC* binding sites are strongly overrepresented in the proximal region of late pollen-specific promoters. By combining our experimental data with in silico genomics and pollen transcriptomics approaches, we identified a considerable number of putative direct target genes of the AtMIKC* transcription factor complexes in pollen, many of which have known or proposed functions in pollen tube growth. The expression of several of these predicted targets is altered in mutant pollen in which all AtMIKC* complexes are affected, and in vitro germination of this mutant pollen is severely impaired. Our data therefore suggest that the AtMIKC* protein complexes play an essential role in transcriptional regulation during late pollen development. PMID:17071640

  15. Class XI Myosins Move Specific Organelles in Pollen Tubes and Are Required for Normal Fertility and Pollen Tube Growth in Arabidopsis1[OPEN

    PubMed Central

    Madison, Stephanie L.; Buchanan, Matthew L.; Glass, Jeremiah D.; McClain, Tarah F.; Park, Eunsook; Nebenführ, Andreas

    2015-01-01

    Pollen tube growth is an essential aspect of plant reproduction because it is the mechanism through which nonmotile sperm cells are delivered to ovules, thus allowing fertilization to occur. A pollen tube is a single cell that only grows at the tip, and this tip growth has been shown to depend on actin filaments. It is generally assumed that myosin-driven movements along these actin filaments are required to sustain the high growth rates of pollen tubes. We tested this conjecture by examining seed set, pollen fitness, and pollen tube growth for knockout mutants of five of the six myosin XI genes expressed in pollen of Arabidopsis (Arabidopsis thaliana). Single mutants had little or no reduction in overall fertility, whereas double mutants of highly similar pollen myosins had greater defects in pollen tube growth. In particular, myo11c1 myo11c2 pollen tubes grew more slowly than wild-type pollen tubes, which resulted in reduced fitness compared with the wild type and a drastic reduction in seed set. Golgi stack and peroxisome movements were also significantly reduced, and actin filaments were less organized in myo11c1 myo11c2 pollen tubes. Interestingly, the movement of yellow fluorescent protein-RabA4d-labeled vesicles and their accumulation at pollen tube tips were not affected in the myo11c1 myo11c2 double mutant, demonstrating functional specialization among myosin isoforms. We conclude that class XI myosins are required for organelle motility, actin organization, and optimal growth of pollen tubes. PMID:26358416

  16. Functional Characterization and Expression Analyses of the Glucose-Specific AtSTP9 Monosaccharide Transporter in Pollen of Arabidopsis1

    PubMed Central

    Schneidereit, Alexander; Scholz-Starke, Joachim; Büttner, Michael

    2003-01-01

    A genomic clone and the corresponding cDNA of a new Arabidopsis monosaccharide transporter AtSTP9 were isolated. Transport analysis of the expressed protein in yeast showed that AtSTP9 is an energy-dependent, uncoupler-sensitive, high-affinity monosaccharide transporter with a Km for glucose in the micromolar range. In contrast to all previously characterized monosaccharide transporters, AtSTP9 shows an unusual specificity for glucose. Reverse transcriptase-polymerase chain reaction analyses revealed that AtSTP9 is exclusively expressed in flowers, and a more detailed approach using AtSTP9 promoter/reporter plants clearly showed that AtSTP9 expression is restricted to the male gametophyte. AtSTP9 expression is not found in other floral organs or vegetative tissues. Further localization on the cellular level using a specific antibody revealed that in contrast to the early accumulation of AtSTP9 transcripts in young pollen, the AtSTP9 protein is only found weakly in mature pollen but is most prominent in germinating pollen tubes. This preloading of pollen with mRNAs has been described for genes that are essential for pollen germination and/or pollen tube growth. The pollen-specific expression found for AtSTP9 is also observed for other sugar transporters and indicates that pollen development and germination require a highly regulated supply of sugars. PMID:12970485

  17. Loss of Pollen-S Function in Two Self-Compatible Selections of Prunus avium Is Associated with Deletion/Mutation of an S Haplotype–Specific F-Box Gene

    PubMed Central

    Sonneveld, Tineke; Tobutt, Kenneth R.; Vaughan, Simon P.; Robbins, Timothy P.

    2005-01-01

    Recently, an S haplotype–specific F-box (SFB) gene has been proposed as a candidate for the pollen-S specificity gene of RNase-mediated gametophytic self-incompatibility in Prunus (Rosaceae). We have examined two pollen-part mutant haplotypes of sweet cherry (Prunus avium). Both were found to retain the S-RNase, which determines stylar specificity, but one (S3′ in JI 2434) has a deletion including the haplotype-specific SFB gene, and the other (S4′ in JI 2420) has a frame-shift mutation of the haplotype-specific SFB gene, causing amino acid substitutions and premature termination of the protein. The loss or significant alteration of this highly polymorphic gene and the concomitant loss of pollen self-incompatibility function provides compelling evidence that the SFB gene encodes the pollen specificity component of self-incompatibility in Prunus. These loss-of-function mutations are inconsistent with SFB being the inactivator of non-self S-RNases and indicate the presence of a general inactivation mechanism, with SFB conferring specificity by protecting self S-RNases from inactivation. PMID:15598801

  18. The role of casein-specific IgA and TGF-β in children with Food Protein-Induced Enterocolitis Syndrome to milk

    PubMed Central

    Konstantinou, George N.; Bencharitiwong, Ramon; Grishin, Alexander; Caubet, Jean-Christoph; Bardina, Luda; Sicherer, Scott H.; Sampson, Hugh A.; Nowak-Węgrzyn, Anna

    2014-01-01

    Background Food protein-induced enterocolitis syndrome (FPIES) is a gastrointestinal hypersensitivity disorder with a poorly understood pathophysiology and no biomarkers to aid in diagnosis. Objective To investigate humoral and cellular responses to casein in children with milk-FPIES, including the role of casein-specific (cs) IgA and T-cell mediated TGF-β responses. Patients and methods Thirty-one children previously diagnosed with milk-FPIES were challenged with milk. Twelve age-matched children with FPIES to other foods and 6 milk-tolerant children without a history of FPIES were used as controls. Casein-specific IgE, IgG, IgG4 and IgA were measured in serum and TGF-β levels in supernatants of casein-stimulated PBMCs. Result Twenty-six children with milk-FPIES reacted (active milk-FPIES) and five tolerated milk (milk-FPIES-resolved) during food challenge. All of them had significantly lower levels of csIgG, csIgG4 and csIgA than control children (p-value<0.001). There were no TGF-β responses in supernatants of active milk-FPIES children. Conclusion Children with milk-FPIES have low levels of csIgG, csIgG4 and csIgA. In particular, children with active FPIES to cow’s milk have deficient T-cell mediated TGF-β responses to casein, rendering TGF-β a promising biomarker in identifying children who are likely to experience FPIES reactions to this allergen. Prospective studies are needed to validate these findings, elucidate their role in FPIES pathophysiology and establish the diagnostic utility of TGF-β in milk-induced FPIES. PMID:25283440

  19. Induction and maintenance of anti‐influenza antigen‐specific nasal secretory IgA levels and serum IgG levels after influenza infection in adults

    PubMed Central

    Fujimoto, Chisa; Takeda, Noriaki; Matsunaga, Atsushi; Sawada, Ayako; Tanaka, Takeshi; Kimoto, Takashi; Shinahara, Wakako; Sawabuchi, Takako; Yamaguchi, Miyoko; Hayama, Masaki; Yanagawa, Hiroaki; Yano, Mihiro; Kido, Hiroshi

    2012-01-01

    Please cite this paper as: Fujimoto et al. (2012) Induction and maintenance of anti‐influenza antigen‐specific nasal secretory IgA levels and serum IgG levels after influenza infection in adults. Influenza and Other Respiratory Viruses 6(6), 396–403. Objectives  To determine the induction and changes in anti‐influenza virus secretory IgA (s‐IgA) levels in nasal washes and serum IgG levels in patients with influenza. Methods  The study recruited 16 patients with influenza aged 35·6 ± 9·6 years in 2007/2008 and 2008/2009 seasons. Nasal washes and serum were obtained throughout the first year. Anti‐viral s‐IgA levels and neutralization activities in nasal washes, and serum anti‐viral IgG levels and hemagglutination inhibition (HI) titers were measured. Results  Anti‐viral(H1N1) s‐IgA to total IgA ratio and neutralizing antibody titer were low in nasal washes of all patients, whereas serum levels of anti‐viral IgG and HI titers varied widely at day 1·4 ± 1·0 postinfection. Both nasal s‐IgA and serum IgG levels later increased significantly, reaching peak levels at day 9·6 ± 3·3 postinfection. The induced nasal s‐IgA then returned toward the initial levels within 300 days, although the levels at day 143 ± 70 were 3·03‐fold of the initial. Individual serum IgG levels also returned toward the initial levels within 300 days, although the mean levels remained high probably because of re‐infection in a subgroup of patients. Although influenza A (H3N2) was a minor epidemic subtype in both flu seasons, a significant rise in nasal anti‐viral (H3N2) s‐IgA levels and a slightly increase in serum IgG levels were noted. Conclusion  Low levels of nasal anti‐viral s‐IgA and neutralizing antibody were noted compared with a wide range of serum anti‐viral IgG and HI titers at the onset of infection. Elevated s‐IgA and IgG returned toward the initial levels within 300 days of infection with minor

  20. Mucosal Immunization of Lactating Female Rhesus Monkeys with a Transmitted/Founder HIV-1 Envelope Induces Strong Env-Specific IgA Antibody Responses in Breast Milk

    PubMed Central

    Fouda, Genevieve G. A.; Amos, Joshua D.; Wilks, Andrew B.; Pollara, Justin; Ray, Caroline A.; Chand, Anjali; Kunz, Erika L.; Liebl, Brooke E.; Whitaker, Kaylan; Carville, Angela; Smith, Shannon; Colvin, Lisa; Pickup, David J.; Staats, Herman F.; Overman, Glenn; Eutsey-Lloyd, Krissey; Parks, Robert; Chen, Haiyan; LaBranche, Celia; Barnett, Susan; Tomaras, Georgia D.; Ferrari, Guido; Montefiori, David C.; Liao, Hua-Xin; Letvin, Norman L.; Haynes, Barton F.

    2013-01-01

    We previously demonstrated that vaccination of lactating rhesus monkeys with a DNA prime/vector boost strategy induces strong T-cell responses but limited envelope (Env)-specific humoral responses in breast milk. To improve vaccine-elicited antibody responses in milk, hormone-induced lactating rhesus monkeys were vaccinated with a transmitted/founder (T/F) HIV Env immunogen in a prime-boost strategy modeled after the moderately protective RV144 HIV vaccine. Lactating rhesus monkeys were intramuscularly primed with either recombinant DNA (n = 4) or modified vaccinia virus Ankara (MVA) poxvirus vector (n = 4) expressing the T/F HIV Env C.1086 and then boosted twice intramuscularly with C.1086 gp120 and the adjuvant MF59. The vaccines induced Env-binding IgG and IgA as well as neutralizing and antibody-dependent cellular cytotoxicity (ADCC) responses in plasma and milk of most vaccinated animals. Importantly, plasma neutralization titers against clade C HIV variants MW965 (P = 0.03) and CAP45 (P = 0.04) were significantly higher in MVA-primed than in DNA-primed animals. The superior systemic prime-boost regimen was then compared to a mucosal-boost regimen, in which animals were boosted twice intranasally with C.1086 gp120 and the TLR 7/8 agonist R848 following the same systemic prime. While the systemic and mucosal vaccine regimens elicited comparable levels of Env-binding IgG antibodies, mucosal immunization induced significantly stronger Env-binding IgA responses in milk (P = 0.03). However, the mucosal regimen was not as potent at inducing functional IgG responses. This study shows that systemic MVA prime followed by either intranasal or systemic protein boosts can elicit strong humoral responses in breast milk and may be a useful strategy to interrupt postnatal HIV-1 transmission. PMID:23596289

  1. Engineered selective plant male sterility through pollen-specific expression of the EcoRI restriction endonuclease.

    PubMed

    Millwood, Reginald J; Moon, Hong S; Poovaiah, Charleson R; Muthukumar, Balasubramaniam; Rice, John Hollis; Abercrombie, Jason M; Abercrombie, Laura L; Green, William Derek; Stewart, Charles Neal

    2016-05-01

    Unintended gene flow from transgenic plants via pollen, seed and vegetative propagation is a regulatory concern because of potential admixture in food and crop systems, as well as hybridization and introgression to wild and weedy relatives. Bioconfinement of transgenic pollen would help address some of these concerns and enable transgenic plant production for several crops where gene flow is an issue. Here, we demonstrate the expression of the restriction endonuclease EcoRI under the control of the tomato pollen-specific LAT52 promoter is an effective method for generating selective male sterility in Nicotiana tabacum (tobacco). Of nine transgenic events recovered, four events had very high bioconfinement with tightly controlled EcoRI expression in pollen and negligible-to-no expression other plant tissues. Transgenic plants had normal morphology wherein vegetative growth and reproductivity were similar to nontransgenic controls. In glasshouse experiments, transgenic lines were hand-crossed to both male-sterile and emasculated nontransgenic tobacco varieties. Progeny analysis of 16 000-40 000 seeds per transgenic line demonstrated five lines approached (>99.7%) or attained 100% bioconfinement for one or more generations. Bioconfinement was again demonstrated at or near 100% under field conditions where four transgenic lines were grown in close proximity to male-sterile tobacco, and 900-2100 seeds per male-sterile line were analysed for transgenes. Based upon these results, we conclude EcoRI-driven selective male sterility holds practical potential as a safe and reliable transgene bioconfinement strategy. Given the mechanism of male sterility, this method could be applicable to any plant species. PMID:26503160

  2. Salivary IgA against sporozoite-specific embryogenesis-related protein (TgERP) in the study of horizontally transmitted toxoplasmosis via T. gondii oocysts in endemic settings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of toxoplasmosis was investigated in endemic settings in Brazil, and calculated by measuring antibodies in two ELISA systems: 1) IgG and IgM from sera tested by commercial conventional ELISA, and 2) IgA, from saliva, and IgG from sera samples tested against a sporozoite-specific prote...

  3. STIL, a peculiar molecule from styles, specifically dephosphorylates the pollen receptor kinase LePRK2 and stimulates pollen tube growth in vitro

    PubMed Central

    2010-01-01

    Background LePRK1 and LePRK2 are two pollen receptor kinases localized to the plasma membrane, where they are present in a high molecular weight complex (LePRK complex). LePRK2 is phosphorylated in mature and germinated pollen, but is dephosphorylated when pollen membranes are incubated with tomato or tobacco style extracts. Results Here we show that LePRK2 dephosphorylation is mediated by a heat-, acid-, base-, DTT- and protease-resistant component from tobacco styles. Using LePRK2 phosphorylation as a tracking assay for purification, style exudates were subjected to chloroform extraction, anionic exchange, and C18 reverse-phase chromatography columns. We finally obtained a single ~3,550 Da compound (as determined by UV-MALDI-TOF MS) that we named STIL (for Style Interactor for LePRKs). STIL increased pollen tube lengths of in vitro germinated pollen in a dose-dependent manner. Conclusion We propose that the LePRK complex perceives STIL, resulting in LePRK2 dephosphorylation and an increase in pollen tube growth. PMID:20175921

  4. Sensitivity and specificity of single IgA and IgG antibody concentrations for early diagnosis of pertussis in adults: an evaluation for outbreak management in public health practice

    PubMed Central

    Mertens, Paul LJM; Stals, Frans S; Steyerberg, Ewout W; Richardus, Jan H

    2007-01-01

    Background An accurate, practical laboratory test is needed to confirm clinical diagnosis of pertussis in adults during the first 3 symptomatic weeks, when treatment is effective and transmission can be interrupted. Methods The sensitivity and specificity of single IgA and IgG levels were assessed in a cohort study of a pertussis epidemic in 99 adults in a closed community. Sensitivities were assessed in the sera of 46 laboratory confirmed clinical pertussis cases during the first 3 weeks. Specificities were calculated in sera of 35 asymptomatic controls without clinical symptoms or laboratory confirmed infections from the same community (internal controls). We compared these specificities with the specificities of single IgA and IgG levels in 4275 external controls from a cross-section of the general Dutch population aged 21–79 years who had not coughed for more than 2 weeks in the past year, and without pertussis diagnoses. The study was done in the Netherlands when whole-cell pertussis vaccine was used in the national vaccination programme. Results Levels of 24 U/ml for IgA and 27 U/ml for IgG gave sensitivities of 100% and 75%, respectively, in the first 2 weeks, 100% in the third week, and 97% after the fourth week. The levels were reached within 2 days after onset of increase, and remained above these levels for roughly 7.2 and 5.1 months, respectively. Specificity was 82% for IgA and 89% for IgG in the internal controls and 90% in the external controls, respectively. Conclusion We suggest levels of 24 U/ml for IgA level and 27 U/ml (= 27 International Units (IU)/ml) for IgG as sensitive, specific, and practical for laboratory confirmation of clinical pertussis in adults in the first 3 weeks of outbreak management. PMID:17553132

  5. Induction of Bronchial Tolerance After 1 Cycle of Monophosphoryl-A-Adjuvanted Specific Immunotherapy in Children With Grass Pollen Allergies

    PubMed Central

    Girod, Katharina; Zielen, Stefan; Schubert, Ralf; Schulze, Johannes

    2016-01-01

    Purpose Subcutaneous allergen-specific immunotherapy (SCIT) is a well-established and clinically effective method to treat allergic diseases, such as rhinitis and asthma. It remains unclear how soon after initiation of an ultra-short course of grass pollen immunotherapy adjuvanted with monophosphoryl lipid A (MPL)-specific bronchial tolerance can be induced. Methods In a prospective study of 69 children double-sensitized to birch and grass pollens (51 males, average age 11.1 years), development of bronchial tolerance after 1 cycle of SCIT for grass was evaluated. In all the patients, the bronchial allergen provocation test (BAP) was performed before and after treatment. According to the results of the first BAP, the patients were divided into 2 groups: those showing a negative BAP with a decrease in FEV1 of <20% (seasonal allergic rhinitis [SAR] group, n=47); and those showing a positive BAP with a decrease in FEV1 of ≥20% (SAR with allergic asthma [SAR and Asthma] group, n=22). All the patients received MPL-adjuvanted, ultra-short course immunotherapy for birch, but only those with a positive BAP to grass received MPL-SCIT for grass. Results After the pollen season, the BAP in the SAR group remained unchanged, while it was improved in the SAR and Asthma group (decrease in FEV1 of 28.8% vs 12.5%, P<0.01). The IgG4 levels increased after SCIT (median before SCIT 0.34 to 11.4 after SCIT), whereas the total and specific IgE levels remained unchanged. Conclusions After 1 cycle of MPL-SCIT, specific bronchial tolerance may be significantly induced, whereas in patients without SCIT, bronchial hyperactivity may remain unchanged. PMID:26922936

  6. A strong inhibitor of gene expression in the 5' untranslated region of the pollen-specific LAT59 gene to tomato.

    PubMed

    Curie, C; McCormick, S

    1997-11-01

    Promoter sequences that direct pollen-specific expression have been previously identified in the LAT59 (for late anther tomato) gene. Here, we show that the LAT59 sequences encoding the 5' untranslated region inhibit expression of reporter genes by > 20-fold in transient expression experiments and up to 300-fold after stable transformation. Inhibition occurred in somatic cells as well as in pollen. Our results indicate that the inhibitor still functions after pollen germination and therefore does not modulate the level of the LAT59 protein during pollen development. The presence of the leader sequence dramatically decreased mRNA accumulation but without affecting translation rate and mRNA stability. We believe that the leader inhibits transcription. We mapped the inhibitor to a region in the leader that coincides with a putative stem-loop and present evidence that this stem-loop participates in inhibition. PMID:9401125

  7. A strong inhibitor of gene expression in the 5' untranslated region of the pollen-specific LAT59 gene to tomato.

    PubMed Central

    Curie, C; McCormick, S

    1997-01-01

    Promoter sequences that direct pollen-specific expression have been previously identified in the LAT59 (for late anther tomato) gene. Here, we show that the LAT59 sequences encoding the 5' untranslated region inhibit expression of reporter genes by > 20-fold in transient expression experiments and up to 300-fold after stable transformation. Inhibition occurred in somatic cells as well as in pollen. Our results indicate that the inhibitor still functions after pollen germination and therefore does not modulate the level of the LAT59 protein during pollen development. The presence of the leader sequence dramatically decreased mRNA accumulation but without affecting translation rate and mRNA stability. We believe that the leader inhibits transcription. We mapped the inhibitor to a region in the leader that coincides with a putative stem-loop and present evidence that this stem-loop participates in inhibition. PMID:9401125

  8. A meta-analysis of the diagnostic accuracy of dengue virus-specific IgA antibody-based tests for detection of dengue infection.

    PubMed

    Alagarasu, K; Walimbe, A M; Jadhav, S M; Deoshatwar, A R

    2016-03-01

    Immunoglobulin A (IgA)-based tests have been evaluated in different studies for their utility in diagnosing dengue infections. In most of the studies, the results were inconclusive because of a small sample size. Hence, a meta-analysis involving nine studies with 2096 samples was performed to assess the diagnostic accuracy of IgA-based tests in diagnosing dengue infections. The analysis was conducted using Meta-Disc software. The results revealed that IgA-based tests had an overall sensitivity, specificity, diagnostic odds ratio, and positive and negative likelihood ratios of 73·9%, 95·2%, 66·7, 22·0 and 0·25, respectively. Significant heterogeneity was observed between the studies. The type of test, infection status and day of sample collection influenced the diagnostic accuracy. The IgA-based diagnostic tests showed a greater accuracy when the samples were collected 4 days after onset of symptoms and for secondary infections. The results suggested that IgA-based tests had a moderate level of accuracy and are diagnostic of the disease. However, negative results cannot be used alone for dengue diagnosis. More prospective studies comparing the diagnostic accuracy of combinations of antigen-based tests with either IgA or IgM are needed and might be useful for suggesting the best strategy for dengue diagnosis. PMID:26289218

  9. Characterization of a lily anther-specific gene encoding cytoskeleton-binding glycoproteins and overexpression of the gene causes severe inhibition of pollen tube growth.

    PubMed

    Wang, Bing-Jyun; Hsu, Yi-Feng; Chen, Yun-Chu; Wang, Co-Shine

    2014-09-01

    This work characterizes an anther/pollen-specific gene that encodes potential intermediate filament (IF)-binding glycoproteins in lily (Lilium longiflorum Thunb. cv. Snow Queen) anthers during the development and pollen germination. LLP13 is a single gene that encodes a polypeptide of 807 amino acids, and a calculated molecular mass of 91 kDa. The protein contains a predicted transmembrane domain at the N-terminus and a conserved domain of unknown function (DUF)593 at the C-terminal half of the polypeptide. Sequence analysis revealed that LLP13 shares significant identity (37-41 %) with two intermediate filament antigen-binding proteins, representing a unique subgroup of DUF593 domain proteins from known rice and Arabidopsis species. The expression of LLP13 gene is anther-specific, and the transcript accumulates only at the stage of pollen maturation. Both premature drying and abscisic acid (ABA) treatment of developing pollen indicated that LLP13 was not induced by desiccation and ABA, but by other developmental cues. Antiserum was raised against the overexpressed LLP13C fragment of the protein in Escherichia coli and affinity-purified antibodies were prepared. Immunoblot analyses revealed that the LLP13 protein was a heterogeneous, anther-specific glycoprotein that accumulated only at the stage of pollen maturation. The protein is not heat-soluble. The level of LLP13 protein remained for 24 h during germination in vitro. Overexpression of LLP13-GFP or GFP-LLP13 in lily pollen tubes caused severe inhibition of tube elongation. The LLP13 protein codistributed with mTalin in growing tubes, suggesting that it apparently decorates actin cytoskeleton and is likely a cytoskeleton-binding protein that binds with IFs that potentially exist in pollen tubes. PMID:24944111

  10. IgA Nephropathy

    MedlinePlus

    ... Kidney Disease and Kidney Failure . [ Top ] How is kidney disease diagnosed? A health care provider diagnoses kidney disease ... levels Control Blood Pressure and Slow Progression of Kidney Disease People with IgA nephropathy that is causing high ...

  11. IgA nephropathy

    MedlinePlus

    ... family history of IgA nephropathy or Henoch Schonlein purpura , a form of vasculitis that affects many parts ... End-stage kidney disease Hypersensitivity vasculitis Nephrotic syndrome Purpura Urine - bloody Update Date 9/22/2015 Updated ...

  12. Pollen Primer

    MedlinePlus

    ... air filters (HEPA) or an electrostatic air filter. Tree Pollen Trees produce pollen earliest, as soon as January in ... distributed miles away. Fewer than 100 kinds of trees cause allergies. Some common ones are catalpa, elm, ...

  13. Pollen Allergy

    MedlinePlus

    ... pollen count, which is often reported by local weather broadcasts or allergy websites, is a measure of how much pollen is in the air. Pollen counts tend to be highest early in the morning on warm, dry, breezy days and lowest during chilly, wet periods. ...

  14. O-glycosylation of serum IgA1 antibodies against mucosal and systemic antigens in IgA nephropathy.

    PubMed

    Smith, Alice C; Molyneux, Karen; Feehally, John; Barratt, Jonathan

    2006-12-01

    In IgA nephropathy (IgAN), serum IgA1 with abnormal O-glycosylation deposits in the glomerular mesangium. The underlying mechanism of this IgA1 O-glycosylation abnormality is poorly understood, but recent evidence argues against a generic defect in B cell glycosyltransferases, suggesting that only a subpopulation of IgA1-committed B cells are affected. For investigation of whether the site of antigen encounter influences IgA1 O-glycosylation, the O-glycosylation of serum IgA1 antibodies against a systemic antigen, tetanus toxoid (TT), and a mucosal antigen, Helicobacter pylori (HP), was studied in patients with IgAN and control subjects. Serum IgA1 was purified from cohorts of patients with IgAN and control subjects with HP infection and after systemic TT immunization. The IgA1 samples were applied to HP- and TT-coated immunoplates to immobilize specific antibodies, and IgA1 O-glycosylation profiles were assessed by binding of the O-glycan-specific lectin Vicia villosa using a modified ELISA technique. Although total serum IgA1 had raised lectin binding in IgAN, the O-glycosylation of the specific IgA1 antibodies to TT and HP did not differ between patients and control subjects. In both groups, IgA1 anti-HP had higher lectin binding than IgA1 anti-TT. This study demonstrates that IgA1 O-glycosylation normally varies in different immune responses and that patients produce the full spectrum of IgA1 O-glycoforms. IgA1 with high lectin binding was produced in response to mucosal HP infection in all subjects. The raised circulating level of this type of IgA1 in IgAN is likely to be a consequence of abnormal systemic responses to mucosally encountered antigens rather than a fundamental defect in B cell O-glycosylation pathways. PMID:17093066

  15. LAP5 and LAP6 encode anther-specific proteins with similarity to chalcone synthase essential for pollen exine development in Arabidopsis.

    PubMed

    Dobritsa, Anna A; Lei, Zhentian; Nishikawa, Shuh-Ichi; Urbanczyk-Wochniak, Ewa; Huhman, David V; Preuss, Daphne; Sumner, Lloyd W

    2010-07-01

    Pollen grains of land plants have evolved remarkably strong outer walls referred to as exine that protect pollen and interact with female stigma cells. Exine is composed of sporopollenin, and while the composition and synthesis of this biopolymer are not well understood, both fatty acids and phenolics are likely components. Here, we describe mutations in the Arabidopsis (Arabidopsis thaliana) LESS ADHESIVE POLLEN (LAP5) and LAP6 that affect exine development. Mutation of either gene results in abnormal exine patterning, whereas pollen of double mutants lacked exine deposition and subsequently collapsed, causing male sterility. LAP5 and LAP6 encode anther-specific proteins with homology to chalcone synthase, a key flavonoid biosynthesis enzyme. lap5 and lap6 mutations reduced the accumulation of flavonoid precursors and flavonoids in developing anthers, suggesting a role in the synthesis of phenolic constituents of sporopollenin. Our in vitro functional analysis of LAP5 and LAP6 using 4-coumaroyl-coenzyme A yielded bis-noryangonin (a commonly reported derailment product of chalcone synthase), while similar in vitro analyses using fatty acyl-coenzyme A as the substrate yielded medium-chain alkyl pyrones. Thus, in vitro assays indicate that LAP5 and LAP6 are multifunctional enzymes and may play a role in both the synthesis of pollen fatty acids and phenolics found in exine. Finally, the genetic interaction between LAP5 and an anther gene involved in fatty acid hydroxylation (CYP703A2) demonstrated that they act synergistically in exine production. PMID:20442277

  16. F-Actin Organization and Pollen Tube Tip Growth in Arabidopsis Are Dependent on the Gametophyte-Specific Armadillo Repeat Protein ARO1[W

    PubMed Central

    Gebert, Marina; Dresselhaus, Thomas; Sprunck, Stefanie

    2008-01-01

    The signal-mediated and spatially controlled assembly and dynamics of actin are crucial for maintaining shape, motility, and tip growth of eukaryotic cells. We report that a novel Armadillo repeat protein in Arabidopsis thaliana, ARMADILLO REPEAT ONLY1 (ARO1), is of fundamental importance for polar growth and F-actin organization in tip-growing pollen tubes. ARO1 is specifically expressed in the vegetative cell of pollen as well as in the egg cell. ARO1-GFP (for green fluorescent protein) fusion proteins accumulate most notably in pollen tube tips and partially colocalize with F-actin in the shank of pollen tubes. ARO1 knockout results in a highly disorganized actin cytoskeleton, growth depolarization, and ultimately tube growth arrest. Tip-localized ARO1-GFP is spatially shifted toward the future site of tip growth, indicating a role of ARO1 in the signaling network controlling tip growth and regulating actin organization. After the pollen tube discharges its contents into the receptive synergid, ARO1-GFP colocalizes with emerging F-actin structures near the site of sperm cell fusion, suggesting additional participation in the mechanism of sperm cell tracking toward the female gametes. The variable localization of ARO1 in the cytoplasm, the nucleus, and at the plasma membrane, however, indicates a multifunctional role like that of β-catenin/Armadillo and the p120 catenins. PMID:18931021

  17. Comparison of the specificities of IgG, IgG-subclass, IgA and IgM reactivities in African and European HIV-infected individuals with an HIV-1 clade C proteome-based array.

    PubMed

    Gallerano, Daniela; Ndlovu, Portia; Makupe, Ian; Focke-Tejkl, Margarete; Fauland, Kerstin; Wollmann, Eva; Puchhammer-Stöckl, Elisabeth; Keller, Walter; Sibanda, Elopy; Valenta, Rudolf

    2015-01-01

    A comprehensive set of recombinant proteins and peptides of the proteome of HIV-1 clade C was prepared and purified and used to measure IgG, IgG-subclass, IgA and IgM responses in HIV-infected patients from Sub-Saharan Africa, where clade C is predominant. As a comparison group, HIV-infected patients from Europe were tested. African and European patients showed an almost identical antibody reactivity profile in terms of epitope specificity and involvement of IgG, IgG subclass, IgA and IgM responses. A V3-peptide of gp120 was identified as major epitope recognized by IgG1>IgG2 = IgG4>IgG3, IgA>IgM antibodies and a C-terminal peptide represented another major peptide epitope for the four IgG subclasses. By contrast, gp41-derived-peptides were mainly recognized by IgG1 but not by the other IgG subclasses, IgA or IgM. Among the non-surface proteins, protease, reverse transcriptase+RNAseH, integrase, as well as the capsid and matrix proteins were the most frequently and strongly recognized antigens which showed broad IgG subclass and IgA reactivity. Specificities and magnitudes of antibody responses in African patients were stable during disease and antiretroviral treatment, and persisted despite severe T cell loss. Using a comprehensive panel of gp120, gp41 peptides and recombinant non-surface proteins of HIV-1 clade C we found an almost identical antibody recognition profile in African and European patients regarding epitopes and involved IgG-sublass, IgA- and IgM-responses. Immune recognition of gp120 peptides and non-surface proteins involved all four IgG subclasses and was indicative of a mixed Th1/Th2 immune response. The HIV-1 clade C proteome-based test allowed diagnosis and monitoring of antibody responses in the course of HIV-infections and assessment of isotype and subclass responses. PMID:25658330

  18. Comparison of the Specificities of IgG, IgG-Subclass, IgA and IgM Reactivities in African and European HIV-Infected Individuals with an HIV-1 Clade C Proteome-Based Array

    PubMed Central

    Gallerano, Daniela; Ndlovu, Portia; Makupe, Ian; Focke-Tejkl, Margarete; Fauland, Kerstin; Wollmann, Eva; Puchhammer-Stöckl, Elisabeth; Keller, Walter; Sibanda, Elopy; Valenta, Rudolf

    2015-01-01

    A comprehensive set of recombinant proteins and peptides of the proteome of HIV-1 clade C was prepared and purified and used to measure IgG, IgG-subclass, IgA and IgM responses in HIV-infected patients from Sub-Saharan Africa, where clade C is predominant. As a comparison group, HIV-infected patients from Europe were tested. African and European patients showed an almost identical antibody reactivity profile in terms of epitope specificity and involvement of IgG, IgG subclass, IgA and IgM responses. A V3-peptide of gp120 was identified as major epitope recognized by IgG1>IgG2 = IgG4>IgG3, IgA>IgM antibodies and a C-terminal peptide represented another major peptide epitope for the four IgG subclasses. By contrast, gp41-derived-peptides were mainly recognized by IgG1 but not by the other IgG subclasses, IgA or IgM. Among the non-surface proteins, protease, reverse transcriptase+RNAseH, integrase, as well as the capsid and matrix proteins were the most frequently and strongly recognized antigens which showed broad IgG subclass and IgA reactivity. Specificities and magnitudes of antibody responses in African patients were stable during disease and antiretroviral treatment, and persisted despite severe T cell loss. Using a comprehensive panel of gp120, gp41 peptides and recombinant non-surface proteins of HIV-1 clade C we found an almost identical antibody recognition profile in African and European patients regarding epitopes and involved IgG-sublass, IgA- and IgM-responses. Immune recognition of gp120 peptides and non-surface proteins involved all four IgG subclasses and was indicative of a mixed Th1/Th2 immune response. The HIV-1 clade C proteome-based test allowed diagnosis and monitoring of antibody responses in the course of HIV-infections and assessment of isotype and subclass responses. PMID:25658330

  19. Identification and Evolution of Functional Alleles of the Previously Described Pollen Specific Myrosinase Pseudogene AtTGG6 in Arabidopsis thaliana

    PubMed Central

    Fu, Lili; Han, Bingying; Tan, Deguan; Wang, Meng; Ding, Mei; Zhang, Jiaming

    2016-01-01

    Myrosinases are β-thioglucoside glucohydrolases and serve as defense mechanisms against insect pests and pathogens by producing toxic compounds. AtTGG6 in Arabidopsis thaliana was previously reported to be a myrosinase pseudogene but specifically expressed in pollen. However, we found that AlTGG6, an ortholog to AtTGG6 in A. lyrata (an outcrossing relative of A. thaliana) was functional, suggesting that functional AtTGG6 alleles may still exist in A. thaliana. AtTGG6 alleles in 29 A. thaliana ecotypes were cloned and sequenced. Results indicate that ten alleles were functional and encoded Myr II type myrosinase of 512 amino acids, and myrosinase activity was confirmed by overexpressing AtTGG6 in Pichia pastoris. However, the 19 other ecotypes had disabled alleles with highly polymorphic frame-shift mutations and diversified sequences. Thirteen frame-shift mutation types were identified, which occurred independently many times in the evolutionary history within a few thousand years. The functional allele was expressed specifically in pollen similar to the disabled alleles but at a higher expression level, suggesting its role in defense of pollen against insect pests such as pollen beetles. However, the defense function may have become less critical after A. thaliana evolved to self-fertilization, and thus resulted in loss of function in most ecotypes. PMID:26907263

  20. Limited Contribution of Mucosal IgA to Simian Immunodeficiency Virus (SIV)-Specific Neutralizing Antibody Response and Virus Envelope Evolution in Breast Milk of SIV-Infected, Lactating Rhesus Monkeys▿

    PubMed Central

    Permar, Sallie R.; Wilks, Andrew B.; Ehlinger, Elizabeth P.; Kang, Helen H.; Mahlokozera, Tatenda; Coffey, Rory T.; Carville, Angela; Letvin, Norman L.; Seaman, Michael S.

    2011-01-01

    Breast milk transmission of human immunodeficiency virus (HIV) remains an important mode of infant HIV acquisition. Interestingly, the majority of infants remain uninfected during prolonged virus exposure via breastfeeding, raising the possibility that immune components in milk prevent mucosal virus transmission. HIV-specific antibody responses are detectable in the milk of HIV-infected women and simian immunodeficiency virus (SIV)-infected monkeys; however, the role of these humoral responses in virus neutralization and local virus quasispecies evolution has not been characterized. In this study, four lactating rhesus monkeys were inoculated with SIVmac251 and monitored for SIV envelope-specific humoral responses and virus evolution in milk and plasma throughout infection. While the kinetics and breadth of the SIV-specific IgG and IgA responses in milk were similar to those in plasma, the magnitude of the milk responses was considerably lower than that of the plasma responses. Furthermore, a neutralizing antibody response against the inoculation virus was not detected in milk samples at 1 year after infection, despite a measurable autologous neutralizing antibody response in plasma samples obtained from three of four monkeys. Interestingly, while IgA is the predominant immunoglobulin in milk, the milk SIV envelope-specific IgA response was lower in magnitude and demonstrated more limited neutralizing capacity against a T-cell line-adapted SIV compared to those of the milk IgG response. Finally, amino acid mutations in the envelope gene product of SIV variants in milk and plasma samples occurred in similar numbers and at similar positions, indicating that the humoral immune pressure in milk does not drive distinct virus evolution in the breast milk compartment. PMID:21041730

  1. Comparative characterization of the iga gene encoding IgA1 protease in Neisseria meningitidis, Neisseria gonorrhoeae and Haemophilus influenzae.

    PubMed

    Lomholt, H; Poulsen, K; Kilian, M

    1995-02-01

    Cloning and sequencing of the IgA1 protease gene (iga) from Neisseria meningitidis strain HF13 showed an overall structure equivalent to iga genes from Neisseria gonorrhoeae and Haemophilus influenzae, although no region corresponding to the gonococcal alpha-peptide was evident. An additional 18 N. meningitidis and 3 H. influenzae iga genes were amplified by the polymerase chain reaction technique and sequenced corresponding approximately to the N-terminal half of the mature enzyme. Comparative analyses of a total of 29 iga genes showed that pathogenic Neisseria have iga genes with a significantly lower degree of heterogeneity than H. influenzae iga genes. Recombinational events indicated by mosaic-like structures corresponding to those found among N. gonorrhoeae protease genes were detected among N. meningitidis iga genes. One region showed characteristic differences in sequence and length which correlated with each of the different cleavage specificities. Meningococci were extremely conserved in this region with no evidence of recombination between isolates of different cleavage specificities. Sequences further downstream showed no obvious relationship with enzyme cleavage type. This region consisted of conserved areas interspersed with highly variable areas. Amino acid sequence homologies in the variable regions of meningococci reflected the antigenic types defined by using polyclonal neutralizing antibodies. PMID:7783620

  2. Serum galactose-deficient IgA1 levels in children with IgA nephropathy.

    PubMed

    Jiang, Mengjie; Jiang, Xiaoyun; Rong, Liping; Xu, Yuanyuan; Chen, Lizhi; Qiu, Zeting; Mo, Ying

    2015-01-01

    Immunoglobulin A nephropathy (IgAN) is an immunopathologic diagnosis based on a renal biopsy, it is characterized by deposits of IgA-containing immune complexes in the mesangium. Adults with IgAN have a galactose-deficient IgA1 in the circulation and glomerular deposition. There are few studies on the glycosylation of serum IgA1 in children with IgAN. To measure the serum levels of galactose-deficient IgA1 in pediatric patients with IgAN, 72 biopsy-proven IgAN children were divided into 3 groups based on the clinical features: isolated hematuria group (24 patients), hematuria and proteinuria group (22 patients), and nephritic syndrome group (26 patients). They were also divided into 3 groups according to pathologic grading: grade I + II group (25 patients), grade III group (33 patients) and grade IV + V group (14 patients). 30 healthy children were recruited as a control group. We used vicia villosa lectin binding enzyme-linked immunosorbent assay to measure the serum levels of galactose-deficient IgA1 in all groups and controls. Serum levels of galactose-deficient IgA1 in children with IgAN were higher than controls (P < 0.01). There were no significant differences in serum levels of galactose-deficient IgA1 among the different clinical and pathologic grading groups. The values of the area under the curve for galactose-deficient IgA1 levels were 0.976 (95% CI, 0.953-1.000). The cutoff point for galactose-deficient IgA1 levels was 0.125, with a sensitivity of 87.5% and a specificity of 83.3%, with a positive predictive value of 92.6% and a negative predictive value of 73.5% (P < 0.01). Children with IgAN presented serum galactose-deficient IgA1, which has shown no relationship with the clinical manifestations and pathologic grading of the disease. Detection of serum galactose-deficient IgA1 levels by vicia villosa lectin binding enzyme-linked immunosorbent assay has a certain clinical value in diagnosis of children with IgAN. PMID:26221341

  3. Serum galactose-deficient IgA1 levels in children with IgA nephropathy

    PubMed Central

    Jiang, Mengjie; Jiang, Xiaoyun; Rong, Liping; Xu, Yuanyuan; Chen, Lizhi; Qiu, Zeting; Mo, Ying

    2015-01-01

    Immunoglobulin A nephropathy (IgAN) is an immunopathologic diagnosis based on a renal biopsy, it is characterized by deposits of IgA-containing immune complexes in the mesangium. Adults with IgAN have a galactose-deficient IgA1 in the circulation and glomerular deposition. There are few studies on the glycosylation of serum IgA1 in children with IgAN. To measure the serum levels of galactose-deficient IgA1 in pediatric patients with IgAN, 72 biopsy-proven IgAN children were divided into 3 groups based on the clinical features: isolated hematuria group (24 patients), hematuria and proteinuria group (22 patients), and nephritic syndrome group (26 patients). They were also divided into 3 groups according to pathologic grading: grade I + II group (25 patients), grade III group (33 patients) and grade IV + V group (14 patients). 30 healthy children were recruited as a control group. We used vicia villosa lectin binding enzyme-linked immunosorbent assay to measure the serum levels of galactose-deficient IgA1 in all groups and controls. Serum levels of galactose-deficient IgA1 in children with IgAN were higher than controls (P < 0.01). There were no significant differences in serum levels of galactose-deficient IgA1 among the different clinical and pathologic grading groups. The values of the area under the curve for galactose-deficient IgA1 levels were 0.976 (95% CI, 0.953-1.000). The cutoff point for galactose-deficient IgA1 levels was 0.125, with a sensitivity of 87.5% and a specificity of 83.3%, with a positive predictive value of 92.6% and a negative predictive value of 73.5% (P < 0.01). Children with IgAN presented serum galactose-deficient IgA1, which has shown no relationship with the clinical manifestations and pathologic grading of the disease. Detection of serum galactose-deficient IgA1 levels by vicia villosa lectin binding enzyme-linked immunosorbent assay has a certain clinical value in diagnosis of children with IgAN. PMID:26221341

  4. IgA immunoassay for the diagnosis of bancroftian filariasis.

    PubMed

    Chanteau, S; Cartel, J L; Martin, P M

    1992-06-01

    In some parasitic infection such as toxoplasmosis, specific IgA is a highly reliable marker of active infection. In bancroftian filariasis, only 10 of 20 (50%) and 3 of 20 (15%) of the microfilaremic patients were positive for IgA anti-Brugia malayi using respectively indirect ELISA and immunocapture ELISA tests. As regard to these low sensitivities, the detection of specific IgA is unlikely to be a useful test for the diagnosis of active Wuchereria bancrofti infection. PMID:1519028

  5. Sites in the CH3 domain of human IgA1 that influence sensitivity to bacterial IgA1 proteases.

    PubMed

    Senior, Bernard W; Woof, Jenny M

    2006-09-15

    The influence of regions, other than the hinge, on the susceptibility of human IgA1 to cleavage by diverse bacterial IgA1 proteases, was examined using IgA1 mutants bearing amino acid deletions, substitutions, and domain swaps. IgA1 lacking the tailpiece retained its susceptibility to cleavage by all of the IgA1 proteases. The domain swap molecule alpha1alpha2gamma3, in which the CH3 domain of IgA1 was exchanged for that of human IgG1, was resistant to cleavage with the type 1 and 2 serine IgA1 proteases of Neisseria meningitidis, Neisseria gonorrhoeae, and Haemophilus influenzae, but remained sensitive to cleavage with the metallo-IgA1 proteases of Streptococcus pneumoniae, Streptococcus oralis, Streptococcus sanguis, and Streptococcus mitis. Substitution of the IgA1 Calpha3 domain motif Pro440 -Phe443 into the corresponding position in the Cgamma3 domain of alpha1alpha2gamma3 resulted now in sensitivity to the type 2 IgA1 protease of N. meningitidis, indicating the possible requirement of these amino acids for sensitivity to this protease. For the H. influenzae type 2 protease, resistance of an IgA1 mutant in which the CH3 domain residues 399-409 were exchanged with those from IgG1, but sensitivity of mutant HuBovalpha3 in which the Calpha3 domain of bovine IgA replaces that of human IgA1, suggests that CH3 domain residues Glu403, Gln406, and Thr409 influence sensitivity to this enzyme. Hence, unlike the situation with the metallo-IgA1 proteases of Streptococcus spp., the sensitivity of human IgA1 to cleavage with the serine IgA1 proteases of Neisseria and Haemophilus involves their binding to different sites specifically in the CH3 domain. PMID:16951354

  6. Sensitization to cereals and peanut evidenced by skin prick test and specific IgE in food-tolerant, grass pollen allergic patients

    PubMed Central

    2011-01-01

    Background The botanical relation between grass and cereal grains may be relevant when diagnosing food allergy to cereals. The aim was to investigate the diagnostic specificity of skin prick test (SPT) and specific immunoglobulin E (sIgE) tests to cereals and peanut in grass pollen allergic subjects without history of, and clinically reactions to foods botanically related to grass. Methods 70 subjects (41 females; mean age 32 years) and 20 healthy controls (13 females; mean age 24 years) were tested by open food challenge (OFC) with cereals and peanut. SPT and sIgE both with Immulite® (Siemens) and ImmunoCAP® (Phadia) to grass and birch pollen, cereals, peanut and bromelain were performed. Results Of the 65 OFC-negative subjects 29-46% (SPT, depending on cut-off), 20% (Immulite) and 38% (ImmunoCAP) had positive results to one or more of the foods tested. Controls were negative in all tests. Cross-reactive carbohydrate determinants (CCD) as evidenced by reaction to bromelain could explain only a minority of the measured IgE-sensitizations. Conclusion Grass pollen allergic patients with documented food tolerance to cereals and peanut may express significant sensitization. False-positive cereal or peanut allergy diagnoses may be a quantitatively important problem both in routine clinical work and epidemiological studies. PMID:22409998

  7. A flavonoid 3-O-glucoside:2″-O-glucosyltransferase responsible for terminal modification of pollen-specific flavonols in Arabidopsis thaliana

    PubMed Central

    Yonekura-Sakakibara, Keiko; Nakabayashi, Ryo; Sugawara, Satoko; Tohge, Takayuki; Ito, Takuya; Koyanagi, Misuzu; Kitajima, Mariko; Takayama, Hiromitsu; Saito, Kazuki

    2014-01-01

    Flavonol 3-O-diglucosides with a 1→2 inter-glycosidic linkage are representative pollen-specific flavonols that are widely distributed in plants, but their biosynthetic genes and physiological roles are not well understood. Flavonoid analysis of four Arabidopsis floral organs (pistils, stamens, petals and calyxes) and flowers of wild-type and male sterility 1 (ms1) mutants, which are defective in normal development of pollen and tapetum, showed that kaempferol/quercetin 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosides accumulated in Arabidopsis pollen. Microarray data using wild-type and ms1 mutants, gene expression patterns in various organs, and phylogenetic analysis of UDP-glycosyltransferases (UGTs) suggest that UGT79B6 (At5g54010) is a key modification enzyme for determining pollen-specific flavonol structure. Kaempferol and quercetin 3-O-glucosyl-(1→2)-glucosides were absent from two independent ugt79b6 knockout mutants. Transgenic ugt79b6 mutant lines transformed with the genomic UGT79B6 gene had the same flavonoid profile as wild-type plants. Recombinant UGT79B6 protein converted kaempferol 3-O-glucoside to kaempferol 3-O-glucosyl-(1→2)-glucoside. UGT79B6 recognized 3-O-glucosylated/galactosylated anthocyanins/flavonols but not 3,5- or 3,7-diglycosylated flavonoids, and prefers UDP-glucose, indicating that UGT79B6 encodes flavonoid 3-O-glucoside:2″-O-glucosyltransferase. A UGT79B6-GUS fusion showed that UGT79B6 was localized in tapetum cells and microspores of developing anthers. PMID:24916675

  8. Interleukin (IL)-21 promotes intestinal IgA response to microbiota.

    PubMed

    Cao, A T; Yao, S; Gong, B; Nurieva, R I; Elson, C O; Cong, Y

    2015-09-01

    Commensal microbiota-specific T helper type 17 (Th17) cells are enriched in the intestines, which can convert into T follicular helper (Tfh) in Peyer's patches, and are crucial for production of intestinal immunoglobulin A (IgA) against microbiota; however, the role of Th17 and Tfh cytokines in regulating the mucosal IgA response to enteric microbiota is still not completely known. In this study, we found that intestinal IgA was impaired in mice deficient in interleukin (IL)-17 or IL-21 signaling. IL-21, but not IL-17, is able to augment B-cell differentiation to IgA(+) cells as mediated by transforming growth factor β1 (TGFβ1) and accelerate IgA class switch recombination (CSR). IL-21 and retinoic acid (RA) induce IgA(+) B-cell development and IgA production and drives autocrine TGFβ1 production to initiate IgA CSR. Repletion of T-cell-deficient TCRβxδ(-/-) mice with Th17 cells specific for commensal bacterial antigen increased the levels of IgA(+) B cells and IgA production in the intestine, which was blocked by neutralizing IL-21. Thus IL-21 functions to strongly augment IgA production under intestinal environment. Furthermore, IL-21 promotes intestinal B-cell homing through α4β7 expression, alone or with TGFβ and RA. Together, IL-21 from microbiota-specific Th17 and/or Tfh cells contributes to robust intestinal IgA levels by enhancing IgA(+) CSR, IgA production and B-cell trafficking into the intestine. PMID:25586558

  9. Interleukin (IL)-21 promotes intestinal IgA response to microbiota

    PubMed Central

    Cao, Anthony T.; Yao, Suxia; Gong, Bin; Nurieva, Roza I.; Elson, Charles O.; Cong, Yingzi

    2014-01-01

    Commensal microbiota-specific Th17 cells are enriched in the intestines, which can convert into Tfh in Peyer’s patches, and are crucial for production of intestinal IgA against microbiota, however, the role of Th17 and Tfh cytokines in regulating the mucosal IgA response to enteric microbiota is still not completely known. In this study, we found that intestinal IgA was impaired in mice deficient in IL-17 or IL-21 signaling. IL-21, but not IL-17, is able to augment B cell differentiation to IgA+ cells as mediated by TGFβ1, and accelerate IgA class switch recombination (CSR). IL-21 and retinoic acid (RA) induce IgA+ B cell development and IgA production, and drives autocrine TGFβ1 production to initiate IgA CSR. Repletion of T cell-deficient TCRβxδ−/− mice with Th17 cells specific for commensal bacterial antigen, increased levels of IgA+ B cells and IgA production in the intestine, which was blocked by neutralizing IL-21. Thus, IL-21 functions to strongly augment IgA production under intestinal environment. Furthermore, IL-21 promotes intestinal B cell homing through α4β7 expression, alone or with TGFβ and RA. Together, IL-21 from microbiota-specific Th17 and/or Tfh cells contributes to robust intestinal IgA levels by enhancing IgA+ CSR, IgA production, and B cell trafficking into the intestine. PMID:25586558

  10. IgA Nephropathy

    PubMed Central

    McCoy, Ralph C.; Abramowsky, Carlos R.; Tisher, C. Craig

    1974-01-01

    From a series of 470 specimens of renal tissue examined by immunofluorescence microscopy, 20 specimens were identified and studied in detail from patients without evidence of systemic disease in which IgA was the predominant localizing immunoglobulin. All patients presented with hematuria which was recurrent or persistent, often being exacerbated by upper respiratory infection. Most of the group pursued a benign clinical course with little evidence of decline in renal function. Histopathologic changes in renal biopsy specimens of most of the group consisted of a proliferative glomerulonephritis of variable intensity. Characteristic alterations were seen by electron microscopy which included the presence of electron-dense deposits within the mesangium, the hilar regions of the glomerulus and the basement membrane of Bowman's capsule. Evidence for activation of complement by the alternate pathway at C3 was found with properdin localization in 14 of 15 specimens and with the absence of detectable Clq and C4 in 15 specimens studied for these early acting components. It is concluded that the combined clinical, morphologic and immunologic findings warrant consideration of IgA nephropathy as a distinct clinicopathologic entity. ImagesFig 1Fig 2Fig 3Fig 4Fig 5Fig 6Fig 7Fig 8Fig 9Fig 10Fig 11 PMID:4601708

  11. Silencing of the Tapetum-Specific Zinc Finger Gene TAZ1 Causes Premature Degeneration of Tapetum and Pollen Abortion in Petunia

    PubMed Central

    Kapoor, Sanjay; Kobayashi, Akira; Takatsuji, Hiroshi

    2002-01-01

    TAZ1 (TAPETUM DEVELOPMENT ZINC FINGER PROTEIN1; renamed from PEThy; ZPT3-2) cDNA was first isolated as an anther-specific cDNA from petunia. Here, we report a functional characterization that includes analysis of spatial and temporal expression profiles and examination of anther phenotypes in TAZ1-silenced plants. TAZ1 showed a biphasic expression pattern. In the premeiotic phase, TAZ1 transcripts were found to accumulate in all cell types of the anther except the tapetum and gametophytic tissues, whereas the postmeiotic phase of anther development was characterized by expression exclusively in the tapetum. Silencing of TAZ1 by cosuppression resulted in aberrant development and precocious degeneration of the tapetum, followed by extensive microspore abortion that started soon after their release from pollen tetrads. A few pollen grains that survived showed reduced flavonol accumulation, defects in pollen wall formation, and poor germination rates. This study demonstrates an essential role for TAZ1 in the postmeiotic phase of tapetum development. PMID:12368491

  12. Measurement of serum levels of eosinophil cationic protein to monitor patients with seasonal respiratory allergy induced by Parietaria pollen (treated and untreated with specific immunotherapy).

    PubMed

    D'Amato, G; Liccardi, G; Russo, M; Saggese, M; D'Amato, M

    1996-04-01

    This trial studied the behavior of a marker of eosinophilic inflammation, eosinophil cationic protein (ECP), in the peripheral blood of two groups of subjects with seasonal allergic respiratory symptoms (rhinitis and mild bronchial asthma) induced by pollen allergens of Parietaria judaica (P.j.) (one group treated and another untreated with specific immunotherapy [SIT]), to determine what contribution these serial measurements might provide, in comparison with various other tools now available for pollinosis monitoring. In a previously randomized order, we selected 25 patients with monosensitization to P.j. pollen allergens; among them, 12 had started SIT with a P.j. extract in autumn 1993. As a control group, 13 patients were untreated. All patients were studied with various tests at four different times: time I-November 1993; time II-February 1994; time III-end of May 1994; and time IV-September 1994. Blood samples for determination of serum ECP were collected at each time. Methacholine challenge tests were performed at times I and III. A pollen count was also carried out. A statistically significant difference (P < 0.05) was observed in mean ECP levels at times I and III in SIT treated and untreated patients. The interaction between groups and time was not significant. No statistically significant difference was found between PD20 FEV1 values at times I and III in either group. After 1 year of treatment, we did not find any effect of SIT on bronchial hyperresponsiveness or on ECP serum values. PMID:8792921

  13. [Development of allergic reactivity to Artemesia pollen during combined sensitization to pollen and microbes].

    PubMed

    Ermekova, R K

    1978-08-01

    Some regularities of formation of hypersensitivity of the immediate type to the pollen of Artemisia absinthium were studied under conditions of combined hypersensitivity to pollen and Brucella abortus 19-BA vaccine strain; the latter was administered 3, 12, and 28 days after the pollen. The degree of specific allergic reconstruction to the pollen was studied by passive skin anaphylaxis after Ovary, indirect degranulation of mast cells of healthy rats, and by general anaphylaxis in response to intravenous injection of the Artemisia absinthium pollen water-salt extract. Early formation of allergy to the pollen was observed in the groups of animals with combined hypersensitivity to the pollen and brucellae. The degree of allergic reactivity to the pollen allergen was more expressed in the groups with combined allergy than in those with pure pollen hypersensitivity at all the stages of this experiment. PMID:99195

  14. Engineering, purification and applications of His-tagged recombinant antibody fragments with specificity for the major birch pollen allergen, bet v1.

    PubMed

    Flicker, S; Laffer, S; Steinberger, P; Alhani, B; Zhu, Y; Laukkanen, M L; Keinänen, K; Kraft, D; Valenta, R

    2000-01-01

    Type I allergy, an immunodisorder affecting almost 20% of the population worldwide, is based on the production of IgE antibodies against per se harmless allergens. We report the expression of hexahistidine-tagged antibody fragments (Fabs) with specificity for Bet v1, the major birch pollen allergen, in Escherichia coli. The cDNA coding for the heavy chain fragment of a mouse monoclonal anti-Bet v1 antibody, Bip 1, was engineered by PCR to contain a hexahistidine-encoding 3' end. The modified Bip1 heavy chain cDNA was co-expressed in E. coli XL-1 Blue with the Bip 1 light chain cDNA using the combinatorial plasmid pComb3H. His-tagged recombinant (r) Bip 1 Fabs were isolated by nickel affinity chromatography and rBip 1 Fabs without His-tag were purified via affinity to rBet v1. rBip 1 Fabs with and without His-tag bound specifically to rBet v1 and, like Bet v1 -specific human serum IgE and rabbit-anti rBet v1 antibodies, cross-reacted with Bet v1-related allergens in other plant-species (alder, oak, hazelnut). We demonstrate the usefulness of His-tagged rBip 1 Fabs (1) for the identification of pollen samples containing Bet v 1 by particle blotting, (2) forthe detection of Bet v1-specific IgE antibodies in human serum samples by sandwich ELISA and (3) for the quantification of Bet v1 in solution. Based on these examples we suggest to use rBip 1 Fabs for the detection of Bet v1 and Bet v1-related allergens in natural allergen sources for allergy prevention, as well as for the standardization of natural allergen extracts produced for diagnosis and immunotherapy of birch pollen allergy. PMID:10722049

  15. Astragalus membranaceus up-regulate Cosmc expression and reverse IgA dys-glycosylation in IgA nephropathy

    PubMed Central

    2014-01-01

    Background Decreased Core I β3-Gal-T-specific molecular chaperone (Cosmc) expression induced IgA1 aberrant glycosylation is the main characteristic of IgA nephropathy (IgAN). This study tried to elucidate the effect of Astragalus membranaceus on Cosmc expression and IgA O-glycosylation of peripheral B lymphocytes in IgAN patients. Methods Peripheral B lymphocytes of 21 IgAN patients and 10 normal controls were isolated and cultured with or without lipopolysaccharide (LPS) and Astragalus membranaceus injection (AMI). Cosmc mRNA and protein expression levels were measured by real-time RT-PCR and Western blot. IgA1 and glycosylation level were determined by enzyme-linked immunosorbent assay (ELISA) and VV lectin-binding method. Results Cosmc mRNA expression and IgA1 O-glycosylation level in IgAN patients was significantly lower than normal controls at baseline. Treatment of LPS could obviously inhibit Cosmc expression and increase the IgA1 secretion in peripheral B lymphocytes of IgAN patients, which resulted in a significantly increase in IgA1 aberrant glycosylation level. Addition of AMI could remarkably up regulated Cosmc expression, decrease IgA1 secretion, and reverse glycosylation level in a dose related manner. Conclusion AMI can up-regulate Cosmc expression of peripheral B lymphocytes and reverse IgA1 aberrant O-glycosylation level, which might be the underlying mechanism of AMI therapy in treating IgAN. Trial registration TCTR20140515001 (Registration Date: 2014-05-15) PMID:24942185

  16. Induction of Fc receptors for IgA on murine T cell hybridoma by human monoclonal IgA and by high molecular weight IgA in IgA nephropathy.

    PubMed Central

    Chevailler, A; Monteiro, R C; Daëron, M; Lesavre, P

    1987-01-01

    A reproducible immunocyto-adherence assay has been developed to study the modulation of Fc receptors for IgA (Fc alpha R), using a murine T cell hybridoma (T2D4), which expresses Fc receptors for all known isotypes of secreted immunoglobulins. By using sheep red blood cells coated with the hapten 2-4-6 trinitrophenyl (TNP), as indicator cells, and a murine monoclonal IgA (MOPC 315) antibody with anti-TNP activity, we were able to study the Fc alpha R on T2D4 cells. We found that: (a) murine Fc alpha R can bind human monoclonal IgA, and this binding is isotype specific since it was inhibited by human monoclonal IgA but not by human monoclonal IgG or IgM; (b) the expression of murine Fc alpha R is unducible by human monoclonal IgA, and this effect is isotype specific since it is not observed with human monoclonal IgM or IgG (c) sera from patients with IgA nephropathy can also induce Fc alpha R expression; by contrast, no induction was observed with normal human sera, (d) in one serum from an IgA-nephropathy patient, the inducer factor was characterized by affinity chromatography on anti-IgA-Sepharose and by gel filtration: high molecular weight IgA, probably IgA aggregates or immune complexes were recognized to be responsible for the induction of murine Fc alpha R expression. PMID:3497739

  17. Dried fruit hypersensitivity and its correlation with pollen allergy.

    PubMed

    Amat Par, P; Sanosa Valls, J; Lluch Pérez, M; Malet Casajuana, A; García Calderón, P A

    1990-01-01

    A group of 102 patients (children and adults) with hypersensitivity to dried fruits and dermo-respiratory pathology underwent "in vivo" tests (skin tests) and "in vitro" tests (histamine release test, specific IgE) using a battery of foods and neumoallergens. We assessed immunoglobulin (IgG, IgA, IgM, IgE) levels as well as the complement (CH50), its components (C3, C4) and the possible presence of circulating immune complexes. Of the dried fruits the almond was the most sensitizing (89%, 87% and 68% of correlation between the clinical history and "in vivo" tests--skin tests--and "in vitro" tests--histamine release test and RAST--, respectively). As regards the other sensitizations, a hypersensitivity to peach was detected in 47% of the cases. As for the association between food allergy and pollen hypersensitivity, the highest percentages were for tree pollen (51%) followed by weeds (27%) and grasses (25%). The complement values did not show significant differences when they were compared with the control population. The statistical study correlating the clinical history with the results of the diagnostic methods--agreements between two or three tests--was positive (p greater than 0.05) for almond and peanut whereas it was negative (p less than 0.005) for hazelnut. PMID:2200245

  18. Amino acid sequence requirements in the hinge of human immunoglobulin A1 (IgA1) for cleavage by streptococcal IgA1 proteases.

    PubMed

    Batten, Margaret R; Senior, Bernard W; Kilian, Mogens; Woof, Jenny M

    2003-03-01

    The amino acid sequence requirements in the hinge of human immunoglobulin A1 (IgA1) for cleavage by IgA1 proteases of different species of Streptococcus were investigated. Recombinant IgA1 antibodies were generated with point mutations at proline 227 and threonine 228, the residues lying on either side of the peptide bond at which all streptococcal IgA1 proteases cleave wild-type human IgA1. The amino acid substitutions produced no major effect upon the structure of the mutant IgA1 antibodies or their functional ability to bind to Fcalpha receptors. However, the substitutions had a substantial effect upon sensitivity to cleavage with some streptococcal IgA1 proteases, with, in some cases, a single point mutation rendering the antibody resistant to a particular IgA1 protease. This effect was least marked with the IgA1 protease from Streptococcus pneumoniae, which showed no absolute requirement for either proline or threonine at residues 227 to 228. By contrast, the IgA1 proteases of Streptococcus oralis, Streptococcus sanguis, and Streptococcus mitis had an absolute requirement for proline at 227 but not for threonine at 228, which could be replaced by valine. There was evidence in S. mitis that proteases from different strains may have different amino acid requirements for cleavage. Remarkably, some streptococcal proteases appeared able to cleave the hinge at a distant alternative site if substitution prevented efficient cleavage of the original site. Hence, this study has identified key residues required for the recognition of the IgA1 hinge as a substrate by streptococcal IgA1 proteases, and it marks a preliminary step towards development of specific enzyme inhibitors. PMID:12595464

  19. Isolation and detection of human IgA using a streptococcal IgA-binding peptide.

    PubMed

    Sandin, Charlotta; Linse, Sara; Areschoug, Thomas; Woof, Jenny M; Reinholdt, Jesper; Lindahl, Gunnar

    2002-08-01

    Bacterial proteins that bind to the Fc part of IgG have found widespread use in immunology. A similar protein suitable for the isolation and detection of human IgA has not been described. Here, we show that a 50-residue synthetic peptide, designated streptococcal IgA-binding peptide (Sap) and derived from a streptococcal M protein, can be used for single-step affinity purification of human IgA. High affinity binding of IgA required the presence in Sap of a C-terminal cysteine residue, not present in the intact M protein. Passage of human serum through a Sap column caused depletion of >99% of the IgA, and elution of the column allowed quantitative recovery of highly purified IgA, for which the proportions of the IgA1 and IgA2 subclasses were the same as in whole serum. Moreover, immobilized Sap could be used for single-step purification of secretory IgA of both subclasses from human saliva, with a recovery of approximately 45%. The Sap peptide could also be used to specifically detect IgA bound to Ag. Together, these data indicate that Sap is a versatile Fc-binding reagent that may open new possibilities for the characterization of human IgA. PMID:12133959

  20. Oral priming with Salmonella Typhi vaccine strain CVD 909 followed by parenteral boost with the S. Typhi Vi capsular polysaccharide vaccine induces CD27+IgD-S. Typhi-specific IgA and IgG B memory cells in humans.

    PubMed

    Wahid, Rezwanul; Pasetti, Marcela F; Maciel, Milton; Simon, Jakub K; Tacket, Carol O; Levine, Myron M; Sztein, Marcelo B

    2011-02-01

    Attenuated live oral typhoid vaccine candidate CVD 909 constitutively expresses Salmonella Typhi capsular polysaccharide antigen (Vi). A randomized, double-blind, heterologous prime-boost clinical study was conducted to determine whether immunity to licensed parenteral Vi vaccine could be enhanced by priming with CVD 909. Priming with CVD 909 elicited higher and persistent, albeit not significant, anti-Vi IgG and IgA following immunization with Vi, than placebo-primed recipients. Vi-specific IgA B memory (B(M)) cells were significantly increased in CVD 909-primed subjects. S. Typhi-specific LPS and flagella IgA B(M) cells were observed in subjects immunized with CVD 909 or with the licensed Vi-negative oral typhoid vaccine Ty21a. CVD 909-induced B(M) cells exhibited a classical B(M) phenotype (i.e., CD3(-)CD19(+)IgD(-)CD27(+)). This is the first demonstration of classical B(M) cells specific for bacterial polysaccharide or protein antigens following typhoid immunization. The persistent IgA B(M) responses demonstrate the capacity of oral typhoid vaccines to prime mucosally relevant immune memory. PMID:21146460

  1. Purification and characterization of chimeric human IgA1 and IgA2 expressed in COS and Chinese hamster ovary cells.

    PubMed

    Morton, H C; Atkin, J D; Owens, R J; Woof, J M

    1993-11-01

    Ag-specific chimeric human IgA molecules, of the two human subclasses, IgA1 and IgA2, have been expressed in two mammalian cell systems. Analysis of the secreted IgA molecules, purified in milligram quantities from stable Chinese hamster ovary transfectants by Ag affinity chromatography, has allowed a direct comparison of the biologic properties of the two subclasses. HPLC gel filtration analysis revealed that in both subclasses, the IgA molecules associate predominantly into dimers. The monomer units are presumed to interact noncovalently, inasmuch as no dimers are evident when the antibodies are subjected to SDS-PAGE. The recombinant antibodies are glycosylated, inasmuch as a lectin blotting procedure revealed that the H chains of both subclasses are recognized by Con A. When subjected to digestion by preparations of IgA1-specific proteases secreted by two pathogenic streptococcal strains, Streptococcus sanguis and Streptococcus oralis, the recombinant IgA molecules behave just as their natural equivalents. Thus, only the chimeric IgA1 molecule is cleaved, with the IgA2 remaining intact. In terms of interaction with natural effector molecules, both recombinant IgA isotypes were shown to interact with Fc alpha receptors on calcitriol-stimulated HL-60 cells with similar affinity, but neither antibody was found to interact with human C1q. The expression system described readily permits manipulation of the human IgA genes, which should lead to a fuller molecular understanding of how this important antibody mediates its function. PMID:8409433

  2. Allergies, asthma, and pollen

    MedlinePlus

    Allergic rhinitis - pollen ... them is your first step toward feeling better. Pollen is a trigger for many people who have allergies and asthma. The types of pollens that are triggers vary from person to person ...

  3. RNA-sequencing analysis reveals abundant developmental stage-specific and immunity-related genes in the pollen beetle Meligethes aeneus.

    PubMed

    Vogel, H; Badapanda, C; Knorr, E; Vilcinskas, A

    2014-02-01

    The pollen beetle (Meligethes aeneus) is a major pest of oilseed rape (Brassica napus) and other cruciferous crops in Europe. Pesticide-resistant pollen beetle populations are emerging, increasing the economic impact of this species. We isolated total RNA from the larval and adult stages, the latter either naïve or immunized by injection with bacteria and yeast. High-throughput RNA sequencing (RNA-Seq) was carried out to establish a comprehensive transcriptome catalogue and to screen for developmental stage-specific and immunity-related transcripts. We assembled the transcriptome de novo by combining sequence tags from all developmental stages and treatments. Gene expression data based on normalized read counts revealed several functional gene categories that were differentially expressed between larvae and adults, particularly genes associated with digestion and detoxification that were induced in larvae, and genes associated with reproduction and environmental signalling that were induced in adults. We also identified many genes associated with microbe recognition, immunity-related signalling and defence effectors, such as antimicrobial peptides (AMPs) and lysozymes. Digital gene expression analysis revealed significant differences in the profile of AMPs expressed in larvae, naïve adults and immune-challenged adults, providing insight into the steady-state differences between developmental stages and the complex transcriptional remodelling that occurs following the induction of immunity. Our data provide insight into the adaptive mechanisms used by phytophagous insects and could lead to the development of more effective control strategies for insect pests. PMID:24252113

  4. Pollen analyses for pollination research, unacetolyzed pollen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollinators can significantly increase the potential yield of crops, but little is known about which pollinators pollinate various crop species. Many pollinators feed on pollen, nectar and plant secretions associated with flowers, and consequently pollen attaches to the pollinators. Identification...

  5. A pollen-, ovule-, and early embryo-specific poly(A) binding protein from Arabidopsis complements essential functions in yeast.

    PubMed Central

    Belostotsky, D A; Meagher, R B

    1996-01-01

    Poly(A) tails of eukaryotic mRNAs serve as targets for regulatory proteins affecting mRNA stability and translation. Differential mRNA polyadenylation and deadenylation during gametogenesis and early development are now widely recognized as mechanisms of translational regulation in animals, but they have not been observed in plants. Here, we report that the expression of the PAB5 gene encoding one of the poly(A) binding proteins (PABPs) in Arabidopsis is restricted to pollen and ovule development and early embryogenesis. Furthermore, PAB5 is capable of rescuing a PABP-deficient yeast strain by partially restoring both poly(A) shortening and translational initiation functions of PABP. However, PAB5 did not restore the linkage of deadenylation and decapping, thus demonstrating that this function of PABP is not essential for viability. Also, like endogenous PABP, PAB5 expressed in yeast demonstrated genetic interaction with a recently characterized yeast protein SIS1, which is also involved in translational initiation. We propose that PAB5 encodes a post-transcriptional regulatory factor acting through molecular mechanisms similar to those reported for yeast PABP. This factor may have evolved further to post-transcriptionally regulate plant sexual reproduction and early development. PMID:8776896

  6. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

    PubMed Central

    Sénéchal, Hélène; Visez, Nicolas; Charpin, Denis; Shahali, Youcef; Peltre, Gabriel; Biolley, Jean-Philippe; Lhuissier, Franck; Couderc, Rémy; Yamada, Ohri; Malrat-Domenge, Audrey; Pham-Thi, Nhân; Poncet, Pascal; Sutra, Jean-Pierre

    2015-01-01

    This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate) on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of “polluen,” some methodological biases are underlined and research tracks in this field are proposed. PMID:26819967

  7. Pollen grains for oral vaccination

    PubMed Central

    Atwe, Shashwati U.; Ma, Yunzhe; Gill, Harvinder Singh

    2015-01-01

    Oral vaccination can offer a painless and convenient method of vaccination. Furthermore, in addition to systemic immunity it has potential to stimulate mucosal immunity through antigen-processing by the gut-associated lymphoid tissues. In this study we propose the concept that pollen grains can be engineered for use as a simple modular system for oral vaccination. We demonstrate feasibility of this concept by using spores of Lycopodium clavatum (clubmoss) (LSs). We show that LSs can be chemically cleaned to remove native proteins to create intact clean hollow LS shells. Empty pollen shells were successfully filled with molecules of different sizes demonstrating their potential to be broadly applicable as a vaccination system. Using ovalbumin (OVA) as a model antigen, LSs formulated with OVA were orally fed to mice. LSs stimulated significantly higher anti-OVA serum IgG and fecal IgA antibodies compared to those induced by use of cholera toxin as a positive-control adjuvant. The antibody response was not affected by pre-neutralization of the stomach acid, and persisted for up to seven months. Confocal microscopy revealed that LSs can translocate in to mouse intestinal wall. Overall, this study lays the foundation of using LSs as a novel approach for oral vaccination. PMID:25151980

  8. Pollen grains for oral vaccination.

    PubMed

    Atwe, Shashwati U; Ma, Yunzhe; Gill, Harvinder Singh

    2014-11-28

    Oral vaccination can offer a painless and convenient method of vaccination. Furthermore, in addition to systemic immunity it has potential to stimulate mucosal immunity through antigen-processing by the gut-associated lymphoid tissues. In this study we propose the concept that pollen grains can be engineered for use as a simple modular system for oral vaccination. We demonstrate feasibility of this concept by using spores of Lycopodium clavatum (clubmoss) (LSs). We show that LSs can be chemically cleaned to remove native proteins to create intact clean hollow LS shells. Empty pollen shells were successfully filled with molecules of different sizes demonstrating their potential to be broadly applicable as a vaccination system. Using ovalbumin (OVA) as a model antigen, LSs formulated with OVA were orally fed to mice. LSs stimulated significantly higher anti-OVA serum IgG and fecal IgA antibodies compared to those induced by use of cholera toxin as a positive-control adjuvant. The antibody response was not affected by pre-neutralization of the stomach acid, and persisted for up to 7 months. Confocal microscopy revealed that LSs can translocate into mouse intestinal wall. Overall, this study lays the foundation of using LSs as a novel approach for oral vaccination. PMID:25151980

  9. HIV-SPECIFIC SECRETORY IGA IN BREAST MILK OF HIV-POSITIVE MOTHERS IS NOT ASSOCIATED WITH PROTECTION AGAINST HIV TRANSMISSION AMONG BREAST-FED INFANTS

    PubMed Central

    Kuhn, Louise; Trabattoni, Daria; Kankasa, Chipepo; Sinkala, Moses; Lissoni, Francesca; Ghosh, Mrinal; Aldrovandi, Grace; Thea, Don; Clerici, Mario

    2009-01-01

    Objectives To test whether secretory immunoglobulin A (sIgA) to human immunodeficiency virus (HIV) antigens in breast milk of HIV-positive women is associated with protection against HIV transmission among breast-fed infants. Study design Nested, case-control design in which HIV-specific sIgA was measured in breast milk collected from 90 HIV-positive women enrolled in a study in Lusaka, Zambia. Milk samples were selected to include 26 HIV-positive mothers with infected infants (transmitters) and 64 mothers with uninfected infants (nontransmitters). Results HIV-specific sIgA was detected more often in breast milk of transmitting mothers (76.9%) than in breast milk of nontransmitting mothers (46.9%, P = .009). There were no significant associations between HIV-specific sIgA in breast milk and other maternal factors, including HIV RNA quantities in breast milk, CD4 count, and plasma RNA quantities. Conclusions HIV-specific sIgA in breast milk does not appear to be a protective factor against HIV transmission among breast-fed infants. PMID:17095329

  10. Concentrated protein body product derived from rice endosperm as an oral tolerogen for allergen-specific immunotherapy--a new mucosal vaccine formulation against Japanese cedar pollen allergy.

    PubMed

    Wakasa, Yuhya; Takagi, Hidenori; Watanabe, Nobumasa; Kitamura, Noriko; Fujiwara, Yoshihiro; Ogo, Yuko; Hayashi, Shimpei; Yang, Lijun; Ohta, Masaru; Thet Tin, Wai Wai; Sekikawa, Kenji; Takano, Makoto; Ozawa, Kenjirou; Hiroi, Takachika; Takaiwa, Fumio

    2015-01-01

    The endoplasmic reticulum-derived type-I protein body (PB-I) from rice endosperm cells is an ideal candidate formulation for the oral delivery of bioencapsulated peptides as tolerogens for allergen-specific immunotherapy. In the present study, PBs containing the deconstructed Japanese cedar pollen allergens Cryptomeria japonica 1 (Cry j 1) and Cry j 2 were concentrated by treatment with thermostable α-amylase at 90°C to remove the starch from milled rice powder, which resulted in a 12.5-fold reduction of dry weight compared to the starting material. The modified Cry j 1 and Cry j 2 antigens in this concentrated PB product were more resistant to enzymatic digestion than those in the milled seed powder despite the absence of intact cell wall and starch, and remained stable for at least 10 months at room temperature without detectable loss or degradation. The high resistance of these allergens could be attributed to changes in protein physicochemical properties induced by the high temperature concentration process, as suggested by the decreased solubility of the antigens and seed proteins in PBs in step-wise-extraction experiments. Confocal microscopy showed that the morphology of antigen-containing PB-Is was preserved in the concentrated PB product. The concentrated PB product induced specific immune tolerance against Cry j 1 and Cry j 2 in mice when orally administered, supporting its potential use as a novel oral tolerogen formulation. PMID:25774686

  11. Concentrated Protein Body Product Derived from Rice Endosperm as an Oral Tolerogen for Allergen-Specific Immunotherapy—A New Mucosal Vaccine Formulation against Japanese Cedar Pollen Allergy

    PubMed Central

    Wakasa, Yuhya; Takagi, Hidenori; Watanabe, Nobumasa; Kitamura, Noriko; Fujiwara, Yoshihiro; Ogo, Yuko; Hayashi, Shimpei; Yang, Lijun; Ohta, Masaru; Thet Tin, Wai Wai; Sekikawa, Kenji; Takano, Makoto; Ozawa, Kenjirou; Hiroi, Takachika; Takaiwa, Fumio

    2015-01-01

    The endoplasmic reticulum-derived type-I protein body (PB-I) from rice endosperm cells is an ideal candidate formulation for the oral delivery of bioencapsulated peptides as tolerogens for allergen-specific immunotherapy. In the present study, PBs containing the deconstructed Japanese cedar pollen allergens Cryptomeria japonica 1 (Cry j 1) and Cry j 2 were concentrated by treatment with thermostable α-amylase at 90°C to remove the starch from milled rice powder, which resulted in a 12.5-fold reduction of dry weight compared to the starting material. The modified Cry j 1 and Cry j 2 antigens in this concentrated PB product were more resistant to enzymatic digestion than those in the milled seed powder despite the absence of intact cell wall and starch, and remained stable for at least 10 months at room temperature without detectable loss or degradation. The high resistance of these allergens could be attributed to changes in protein physicochemical properties induced by the high temperature concentration process, as suggested by the decreased solubility of the antigens and seed proteins in PBs in step-wise-extraction experiments. Confocal microscopy showed that the morphology of antigen-containing PB-Is was preserved in the concentrated PB product. The concentrated PB product induced specific immune tolerance against Cry j 1 and Cry j 2 in mice when orally administered, supporting its potential use as a novel oral tolerogen formulation. PMID:25774686

  12. Neutrophils negatively regulate induction of mucosal IgA responses after sublingual immunization.

    PubMed

    Jee, J; Bonnegarde-Bernard, A; Duverger, A; Iwakura, Y; Cormet-Boyaka, E; Martin, T L; Steiner, H E; Bachman, R C; Boyaka, P N

    2015-07-01

    Induction of mucosal immunoglobulin-A (IgA) capable of providing a first line of defense against bacterial and viral pathogens remains a major goal of needle-free vaccines given via mucosal routes. Innate immune cells are known to play a central role in induction of IgA responses by mucosal vaccines, but the relative contribution of myeloid cell subsets to these responses has not firmly been established. Using an in vivo model of sublingual vaccination with Bacillus anthracis edema toxin (EdTx) as adjuvant, we examined the role of myeloid cell subsets for mucosal secretory IgA responses. Sublingual immunization of wild-type mice resulted in a transient increase of neutrophils in sublingual tissues and cervical lymph nodes. These mice later developed Ag-specific serum IgG responses, but not serum or mucosal IgA. Interestingly, EdTx failed to increase neutrophils in sublingual tissues and cervical lymph nodes of IKKβ(ΔMye) mice, and these mice developed IgA responses. Partial depletion of neutrophils before immunization of wild-type mice allowed the development of both mucosal and serum IgA responses. Finally, co-culture of B cells with neutrophils from either wild-type or IKKβ(ΔMye) mice suppressed secretion of IgA, but not IgM or IgG. These results identify a new role for neutrophils as negative regulators of IgA responses. PMID:25563500

  13. Neutrophils negatively regulate induction of mucosal IgA responses after sublingual immunization

    PubMed Central

    Jee, Junbae; Bonnegarde-Bernard, Astrid; Duverger, Alexandra; Iwakura, Yoichiro; Cormet-Boyaka, Estelle; Martin, Tara L.; Steiner, Haley E.; Bachman, Ryan C.; Boyaka, Prosper N.

    2015-01-01

    Induction of mucosal IgA capable of providing a first line of defense against bacterial and viral pathogens remains a major goal of needle-free vaccines given via mucosal routes. Innate immune cells are known to play a central role in induction of IgA responses by mucosal vaccines, but the relative contribution of myeloid cell subsets to these responses has not firmly been established. Using an in vivo model of sublingual vaccination with Bacillus anthracis edema toxin (EdTx) as adjuvant, we examined the role of myeloid cell subsets for mucosal secretory IgA responses. Sublingual immunization of wild-type mice resulted in a transient increase of neutrophils in sublingual tissues and cervical lymph nodes. These mice later developed Ag-specific serum IgG responses, but not serum or mucosal IgA. Interestingly, EdTx failed to increase neutrophils in sublingual tissues of IKKβΔMye mice, and these mice developed IgA responses. Partial depletion of neutrophils before immunization of wild-type mice allowed the development of both mucosal and serum IgA responses. Finally, co-culture of B cells with neutrophils from either wild-type or IKKβΔMye mice suppressed production of IgA, but not IgM or IgG. These results identify a new role for neutrophils as negative regulators of IgA responses. PMID:25563500

  14. Allergenic pollen and pollen allergy in Europe.

    PubMed

    D'Amato, G; Cecchi, L; Bonini, S; Nunes, C; Annesi-Maesano, I; Behrendt, H; Liccardi, G; Popov, T; van Cauwenberge, P

    2007-09-01

    The allergenic content of the atmosphere varies according to climate, geography and vegetation. Data on the presence and prevalence of allergenic airborne pollens, obtained from both aerobiological studies and allergological investigations, make it possible to design pollen calendars with the approximate flowering period of the plants in the sampling area. In this way, even though pollen production and dispersal from year to year depend on the patterns of preseason weather and on the conditions prevailing at the time of anthesis, it is usually possible to forecast the chances of encountering high atmospheric allergenic pollen concentrations in different areas. Aerobiological and allergological studies show that the pollen map of Europe is changing also as a result of cultural factors (for example, importation of plants such as birch and cypress for urban parklands), greater international travel (e.g. colonization by ragweed in France, northern Italy, Austria, Hungary etc.) and climate change. In this regard, the higher frequency of weather extremes, like thunderstorms, and increasing episodes of long range transport of allergenic pollen represent new challenges for researchers. Furthermore, in the last few years, experimental data on pollen and subpollen-particles structure, the pathogenetic role of pollen and the interaction between pollen and air pollutants, gave new insights into the mechanisms of respiratory allergic diseases. PMID:17521313

  15. Wind-pollination and the roles of pollen allergenic proteins.

    PubMed

    Songnuan, Wisuwat

    2013-12-01

    Over the past few decades, there has been an explosion of understanding of the molecular nature of major allergens contained within pollens from the most important allergenic plant species. Most major allergens belong to only a few protein families. Protein characteristics, cross-reactivity, structures, and IgE binding epitopes have been determined for several allergens. These efforts have led to significant improvements in specific immunotherapy, yet there has been little discussion about the physiological functions of these proteins. Even with large amounts of available information about allergenic proteins from pollens, the incidence of pollen allergy continuously increases worldwide. The reason for this increase is unclear and is most likely due to a combination of factors. One important culprit might be a change in the pollen itself. Knowledge about pollen biology and how pollen is changing as a result of more extreme environmental conditions might improve our understanding of the disease. This review focuses on the characteristics of plants producing allergenic pollens that are relevant to pollen allergy, including the phylogenetic relationships, pollen dispersal distances, amounts of pollen produced, amounts of protein in each type of pollen, and how allergenic proteins are released from pollens. In addition, the physiological roles of major allergenic protein families will be discussed to help us understand why some of these proteins become allergens and why GMO plants with hypoallergenic pollens may not be successful. PMID:24383968

  16. Tear and serum antibody levels in ocular herpetic infection: diagnostic precision of secretory IgA.

    PubMed Central

    Fox, P D; Khaw, P T; McBride, B W; McGill, J I; Ward, K A

    1986-01-01

    A sensitive enzyme linked immunosorbent assay (ELISA) was developed to evaluate the potential of herpes simplex virus (HSV) specific antibodies in the diagnosis of herpetic eye infection. The presence of HSV specific secretory IgA (sIgA) in tears was found to be diagnostic of infection. However, serum and tear HSV specific IgG and IgA were not considered reliable indicators of active infection. PMID:3741822

  17. Cryptosporidium parvum in calves: kinetics and immunoblot analysis of specific serum and local antibody responses (immunoglobulin A [IgA], IgG, and IgM) after natural and experimental infections.

    PubMed Central

    Peeters, J E; Villacorta, I; Vanopdenbosch, E; Vandergheynst, D; Naciri, M; Ares-Mazás, E; Yvoré, P

    1992-01-01

    Fecal and serum anti-Cryptosporidium parvum immunoglobulin A (IgA), IgM, and IgG were monitored by an enzyme-linked immunosorbent assay after experimental and natural infection of calves with C. parvum. Although all experimentally infected calves showed high levels of colostral antibodies in the feces, they acquired C. parvum infection. Three of five animals died. Calves which acquired natural infection showed only diarrhea. Levels of colostral coproantibodies dropped quickly. Experimental infection was followed by a rise in local anti-C. parvum IgM levels from day 5 postinfection (p.i.). IgM peaked at day 14 p.i. and then disappeared quickly. Anti-C. parvum IgA levels rose between days 7 and 14 p.i. and decreased slowly. Rising levels of coproantibodies coincided with falling oocyst output. Fecal anti-C. parvum IgG levels rose slightly during oocyst output, and IgG disappeared 3 weeks p.i. Similar kinetics were established in naturally infected calves. Although fecal anti-C. parvum IgA levels declined slowly, reinfections were established 5, 7, and 14 weeks after the primary contact. Serum anti-C. parvum IgG levels rose during maximal oocyst excretion, whereas serum anti-C. parvum IgA levels peaked later than did local IgA levels. Challenge reinfection of naturally infected calves at day 112 was not followed by clinical signs or oocyst output or by a secondary antibody response. Sequential Western immunoblotting with fecal extracts revealed up to 32 different parasite antigens. Convalescent-phase sera recognized up to 23 antigens. Fecal IgA reacted intensely with antigens with relative molecular weights (M(r)) of approximately 11,000 and 15,000. These antigens were not recognized by convalescent-phase serum IgG. Both local IgA and serum IgG also showed strong reactions with 23,000- and 44,000-M(r) antigens and with several antigens of between 66,200 and 200,000 M(r). Most bands remained detectable for at least 16 weeks p.i. Images PMID:1587597

  18. DNA Methylation in Cosmc Promoter Region and Aberrantly Glycosylated IgA1 Associated with Pediatric IgA Nephropathy

    PubMed Central

    Sun, Qiang; Zhang, Jianqian; Zhou, Nan; Liu, Xiaorong; Shen, Ying

    2015-01-01

    IgA nephropathy (IgAN) is one of the most common glomerular diseases leading to end-stage renal failure. Elevation of aberrantly glycosylated IgA1 is a key feature of it. The expression of the specific molecular chaperone of core1ß1, 3galactosyl transferase (Cosmc) is known to be reduced in IgAN. We aimed to investigate whether the methylation of CpG islands of Cosmc gene promoter region could act as a possible mechanism responsible for down-regulation of Cosmc and related higher secretion of aberrantly glycosylated IgA1in lymphocytes from children with IgA nephropathy. Three groups were included: IgAN children (n = 26), other renal diseases (n = 11) and healthy children (n = 13). B-lymphocytes were isolated and cultured, treated or not with IL-4 or 5-Aza-2’-deoxycytidine (AZA). The levels of DNA methylation of Cosmc promotor region were not significantly different between the lymphocytes of the three children populations (P = 0.113), but there were significant differences between IgAN lymphocytes and lymphocytes of the other two children populations after IL-4 (P<0.0001) or AZA (P<0.0001). Cosmc mRNA expression was low in IgAN lymphocytes compared to the other two groups (P<0.0001). The level of aberrantly glycosylated IgA1 was markedly higher in IgAN group compared to the other groups (P<0.0001). After treatment with IL-4, the levels of Cosmc DNA methylation and aberrantly glycosylated IgA1 in IgAN lymphocytes were remarkably higher than the other two groups (P<0.0001) with more markedly decreased Cosmc mRNA content (P<0.0001). After treatment with AZA, the levels in IgAN lymphocytes were decreased, but was still remarkably higher than the other two groups (P<0.0001), while Cosmc mRNA content in IgAN lymphocytes were more markedly increased than the other two groups (P<0.0001). The alteration of DNA methylation by IL-4 or AZA specifically correlates in IgAN lymphocytes with alterations in Cosmc mRNA expression and with the level of aberrantly glycosylated IgA1

  19. Presence of circulating macromolecular IgA in patients with hematuria due to primary IgA nephropathy

    SciTech Connect

    Valentijn, R.M.; Kauffmann, R.H.; de la Riviere, G.B.; Daha, M.R.; Van, E.S.

    1983-03-01

    The relation between renal histologic features and the presence of circulating immune complexes was studied in 50 patients with hematuria. Primary IgA nephropathy was found in 25 patients, and various other forms of glomerulopathy were seen in the remaining 25 patients. Circulating immune complexes were detected with the 125I-C1q-binding assay, the conglutinin-binding assay, and the anti-IgA inhibition binding assay, the latter detecting specifically IgA-containing immune complex-like material. The 125I-C1q-binding assay gave negative findings for all patients except one. With the conglutinin-binding assay, immune complexes were found in a similar frequency for patients with and without IgA nephropathy. However, the anti-IgA inhibition binding assay gave positive results only in patients with primary IgA nephropathy (68 percent) and in none of the other patients. Sucrose density ultracentrifugation, as well as experiments in which the anti-IgA inhibition binding assay was performed with and without pretreatment of serum with polyethylene glycol, showed the presumed IgA immune complexes to have intermediate sedimentation coefficients (11 to 21S). The presence and level of this macromolecular IgA in the circulation correlated significantly (p less than 0.001) with the presence of hematuria in patients who had this clinical manifestation intermittently. Furthermore, a significant correlation (r . 0.69, p less than 0.0001) was found between the degree of hematuria and the degree of positive findings of the anti-IgA inhibition binding assay. This study shows that in patients presenting with hematuria, a positive finding on the anti-IgA inhibition binding assay is restricted to patients with primary IgA nephropathy and therefore could be of diagnostic value.

  20. The influence of costimulation and regulatory CD4+ T cells on intestinal IgA immune responses.

    PubMed

    Gärdby, E; Kagrdic, D; Kjerrulf, M; Bromander, A; Vajdy, M; Hörnquist, E; Lycke, N

    1998-01-01

    It is thought that IgA B-cell differentiation is highly dependent on activated CD4+ T cells. In particular, cell-cell interactions in the Peyer's patches involving CD40 and/or CD80/CD86 have been implicated in germinal-center formation and IgA B-cell development. Also soluble factors, such as IL-4, IL-5, IL-6, and TGF beta may be critical for IgA B-cell differentiation in vivo. Here we report on some paradoxical findings with regard to IgA B-cell differentiation and specific mucosal immune responses that we have recently made using gene knockout mice. More specifically, we have investigated to what extent absence of CD4+ T cells, relevant cytokines, or T-cell-B-cell interactions would influence IgA B-cell differentiation in vivo. Using CD4- or IL-4-gene knockout mice or mice made transgenic for CTLA4Ig, we found that, although specific responses were impaired, total IgA production and IgA B-cell differentiation appeared to proceed normally. However, a poor correlation was found between, on the one hand, GC formation and IgA differentiation and, on the other hand, the ability to respond to T-cell-dependent soluble protein antigens in these mice. Thus, despite the various deficiencies in CD4+ T-cell functions seemingly intact IgA B-cell development was observed. PMID:9716905

  1. Pollen Allergens for Molecular Diagnosis.

    PubMed

    Pablos, Isabel; Wildner, Sabrina; Asam, Claudia; Wallner, Michael; Gadermaier, Gabriele

    2016-04-01

    Pollen allergens are one of the main causes of type I allergies affecting up to 30 % of the population in industrialized countries. Climatic changes affect the duration and intensity of pollen seasons and may together with pollution contribute to increased incidences of respiratory allergy and asthma. Allergenic grasses, trees, and weeds often present similar habitats and flowering periods compromising clinical anamnesis. Molecule-based approaches enable distinction between genuine sensitization and clinically mostly irrelevant IgE cross-reactivity due to, e. g., panallergens or carbohydrate determinants. In addition, sensitivity as well as specificity can be improved and lead to identification of the primary sensitizing source which is particularly beneficial regarding polysensitized patients. This review gives an overview on relevant pollen allergens and their usefulness in daily practice. Appropriate allergy diagnosis is directly influencing decisions for therapeutic interventions, and thus, reliable biomarkers are pivotal when considering allergen immunotherapy in the context of precision medicine. PMID:27002515

  2. [The epidemiology of pollen allergy].

    PubMed

    Charpin, D; Caillaud, D

    2014-04-01

    The prevalence of seasonal allergic rhinitis can be established through surveys performed in a sample of the general population. These surveys are based on a questionnaire, which could lead to an overestimate of prevalence rates, and on measurements of specific IgE, which need to be interpreted in the light of the responses to the questionnaire. Such surveys are few in France and need to be updated. Risk factors for seasonal allergic rhinitis are genetic, epigenetic and environmental. Relationships between exposure to pollen and health can be documented through ecological and panel surveys. Panel surveys may give information on threshold levels and dose-response relationships. In addition to pollen exposure, global warming and air pollutants act as cofactors. Monitoring of both pollen exposure and its health effects should be encouraged and strengthened. PMID:24750956

  3. Pollen (quick guide)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    What is pollen, and is it haploid or diploid? Pollen is a crucial stage of the plant life cycle — without pollen there will be no seed. When someone says “Think of a plant,” the plant you think of (whether it’s a tree, a tomato plant, or a geranium) is a sporophyte. Most land plants are sporophytes...

  4. The Tetraspanin CD37 Protects Against Glomerular IgA Deposition and Renal Pathology

    PubMed Central

    Rops, Angelique L.; Figdor, Carl G.; van der Schaaf, Alie; Tamboer, Wim P.; Bakker, Marinka A.; Berden, Jo H.; Dijkman, Henry B.P.M.; Steenbergen, Eric J.; van der Vlag, Johan; van Spriel, Annemiek B.

    2010-01-01

    The tetraspanin protein CD37 is a leukocyte-specific transmembrane protein that is highly expressed on B cells. CD37-deficient (CD37−/−) mice exhibit a 15-fold increased level of immunoglobulin A (IgA) in serum and elevated numbers of IgA+ plasma cells in lymphoid organs. Here, we report that CD37−/− mice spontaneously develop renal pathology with characteristics of human IgA nephropathy. In young naïve CD37−/− mice, mild IgA deposition in glomeruli was observed. However, CD37−/− mice developed high titers of IgA immune complexes in serum during aging, which was associated with increased glomerular IgA deposition. Severe mesangial proliferation, fibrosis, and hyalinosis were apparent in aged CD37−/− mice, whereas albuminuria was mild. To further evaluate the role of CD37 in glomerular disease, we induced anti–glomerular basement membrane (GBM) nephritis in mice. CD37−/− mice developed higher IgA serum levels and glomerular deposits of anti-GBM IgA compared with wild-type mice. Importantly, glomerular macrophage and neutrophil influx was significantly higher in CD37−/− mice during both the heterologous and autologous phase of anti-GBM nephritis. Taken together, tetraspanin CD37 controls the formation of IgA-containing immune complexes and glomerular IgA deposition, which induces influx of inflammatory myeloid cells. Therefore, CD37 may protect against the development of IgA nephropathy. PMID:20348240

  5. The Tetraspanin Protein CD37 Regulates IgA Responses and Anti-Fungal Immunity

    PubMed Central

    van Spriel, Annemiek B.; Sofi, Mariam; Gartlan, Kate H.; van der Schaaf, Alie; Verschueren, Ineke; Torensma, Ruurd; Raymakers, Reinier A. P.; Loveland, Bruce E.; Netea, Mihai G.; Adema, Gosse J.

    2009-01-01

    Immunoglobulin A (IgA) secretion by plasma cells in the immune system is critical for protecting the host from environmental and microbial infections. However, the molecular mechanisms underlying the generation of IgA+ plasma cells remain poorly understood. Here, we report that the B cell–expressed tetraspanin CD37 inhibits IgA immune responses in vivo. CD37-deficient (CD37−/−) mice exhibit a 15-fold increased level of IgA in serum and significantly elevated numbers of IgA+ plasma cells in spleen, mucosal-associated lymphoid tissue, as well as bone marrow. Analyses of bone marrow chimeric mice revealed that CD37–deficiency on B cells was directly responsible for the increased IgA production. We identified high local interleukin-6 (IL-6) production in germinal centers of CD37−/− mice after immunization. Notably, neutralizing IL-6 in vivo reversed the increased IgA response in CD37−/− mice. To demonstrate the importance of CD37—which can associate with the pattern-recognition receptor dectin-1—in immunity to infection, CD37−/− mice were exposed to Candida albicans. We report that CD37−/− mice are evidently better protected from infection than wild-type (WT) mice, which was accompanied by increased IL-6 levels and C. albicans–specific IgA antibodies. Importantly, adoptive transfer of CD37−/− serum mediated protection in WT mice and the underlying mechanism involved direct neutralization of fungal cells by IgA. Taken together, tetraspanin protein CD37 inhibits IgA responses and regulates the anti-fungal immune response. PMID:19282981

  6. Phosphoproteomics Profiling of Tobacco Mature Pollen and Pollen Activated in vitro.

    PubMed

    Fíla, Jan; Radau, Sonja; Matros, Andrea; Hartmann, Anja; Scholz, Uwe; Feciková, Jana; Mock, Hans-Peter; Čapková, Věra; Zahedi, René Peiman; Honys, David

    2016-04-01

    Tobacco mature pollen has extremely desiccated cytoplasm, and is metabolically quiescent. Upon re-hydration it becomes metabolically active and that results in later emergence of rapidly growing pollen tube. These changes in cytoplasm hydration and metabolic activity are accompanied by protein phosphorylation. In this study, we subjected mature pollen, 5-min-activated pollen, and 30-min-activated pollen to TCA/acetone protein extraction, trypsin digestion and phosphopeptide enrichment by titanium dioxide. The enriched fraction was subjected to nLC-MS/MS. We identified 471 phosphopeptides that carried 432 phosphorylation sites, position of which was exactly matched by mass spectrometry. These 471 phosphopeptides were assigned to 301 phosphoproteins, because some proteins carried more phosphorylation sites. Of the 13 functional groups, the majority of proteins were put into these categories: transcription, protein synthesis, protein destination and storage, and signal transduction. Many proteins were of unknown function, reflecting the fact that male gametophyte contains many specific proteins that have not been fully functionally annotated. The quantitative data highlighted the dynamics of protein phosphorylation during pollen activation; the identified phosphopeptides were divided into seven groups based on the regulatory trends. The major group comprised mature pollen-specific phosphopeptides that were dephosphorylated during pollen activation. Several phosphopeptides representing the same phosphoprotein had different regulation, which pinpointed the complexity of protein phosphorylation and its clear functional context. Collectively, we showed the first phosphoproteomics data on activated pollen where the position of phosphorylation sites was clearly demonstrated and regulatory kinetics was resolved. PMID:26792808

  7. Mutations in Bruton's tyrosine kinase impair IgA responses.

    PubMed

    Mitsuiki, Noriko; Yang, Xi; Bartol, Sophinus J W; Grosserichter-Wagener, Christina; Kosaka, Yoshiyuki; Takada, Hidetoshi; Imai, Kohsuke; Kanegane, Hirokazu; Mizutani, Shuki; van der Burg, Mirjam; van Zelm, Menno C; Ohara, Osamu; Morio, Tomohiro

    2015-03-01

    X-linked agammaglobulinemia (XLA) is a primary immunodeficiency caused by mutations in Bruton's tyrosine kinase (BTK), and is characterized by markedly decreased numbers of blood B cells and an absence of all immunoglobulin isotypes. We performed whole exome sequencing in a male pediatric patient with dysgammaglobulinemia with IgA deficiency. Genetic analysis revealed a BTK missense mutation (Thr316Ala). To investigate whether a BTK mutation underlay this antibody deficiency with marked decrease of IgA in this patient, we performed functional analyses of B cells and phagocytes, and molecular analyses of somatic hypermutation and class switch recombination. The BTK missense mutation resulted in B cells with reduced BTK and high IgM expression. Equal proportions of CD19(low) and CD19(normal) fractions were observed, and both included naïve and memory B cells. Calcium influx and phospholipase Cγ2 phosphorylation upon IgM stimulation were marginally impaired in CD19(low), but not in CD19(+) B cells. Similar to XLA patients, IgA transcripts showed low SHM levels, whereas IgG transcripts were hardly affected. Our analyses suggest that the BTK mutation likely underlies the disease in this case, and that hypomorphic BTK mutations can result in normal circulating B cell numbers, but specifically impair IgA responses. PMID:25589397

  8. The Origin and Activities of IgA1-Containing Immune Complexes in IgA Nephropathy

    PubMed Central

    Knoppova, Barbora; Reily, Colin; Maillard, Nicolas; Rizk, Dana V.; Moldoveanu, Zina; Mestecky, Jiri; Raska, Milan; Renfrow, Matthew B.; Julian, Bruce A.; Novak, Jan

    2016-01-01

    IgA nephropathy (IgAN) is the most common primary glomerulonephritis, frequently leading to end-stage renal disease, as there is no disease-specific therapy. IgAN is diagnosed from pathological assessment of a renal biopsy specimen based on predominant or codominant IgA-containing immunodeposits, usually with complement C3 co-deposits and with variable presence of IgG and/or IgM. The IgA in these renal deposits is galactose-deficient IgA1, with less than a full complement of galactose residues on the O-glycans in the hinge region of the heavy chains. Research from the past decade led to the definition of IgAN as an autoimmune disease with a multi-hit pathogenetic process with contributing genetic and environmental components. In this process, circulating galactose-deficient IgA1 (autoantigen) is bound by antiglycan IgG or IgA (autoantibodies) to form immune complexes. Some of these circulating complexes deposit in glomeruli, and thereby activate mesangial cells and induce renal injury through cellular proliferation and overproduction of extracellular matrix components and cytokines/chemokines. Glycosylation pathways associated with production of the autoantigen and the unique characteristics of the corresponding autoantibodies in patients with IgAN have been uncovered. Complement likely plays a significant role in the formation and the nephritogenic activities of these complexes. Complement activation is mediated through the alternative and lectin pathways and probably occurs systemically on IgA1-containing circulating immune complexes as well as locally in glomeruli. Incidence of IgAN varies greatly by geographical location; the disease is rare in central Africa but accounts for up to 40% of native-kidney biopsies in eastern Asia. Some of this variation may be explained by genetically determined influences on the pathogenesis of the disease. Genome-wide association studies to date have identified several loci associated with IgAN. Some of these loci are associated

  9. Maize pollen is an important allergen in occupationally exposed workers

    PubMed Central

    2011-01-01

    Background The work- or environmental-related type I sensitization to maize pollen is hardly investigated. We sought to determine the prevalence of sensitization to maize pollen among exposed workers and to identify the eliciting allergens. Methods In July 2010, 8 out of 11 subjects were examined who were repeatedly exposed to maize pollen by pollinating maize during their work in a biological research department. All 8 filled in a questionnaire and underwent skin prick testing (SPT) and immune-specific analyses. Results 5 out of the 8 exposed subjects had repeatedly suffered for at least several weeks from rhinitis, 4 from conjunctivitis, 4 from urticaria, and 2 from shortness of breath upon occupational exposure to maize pollen. All symptomatic workers had specific IgE antibodies against maize pollen (CAP class ≥ 1). Interestingly, 4 of the 5 maize pollen-allergic subjects, but none of the 3 asymptomatic exposed workers had IgE antibodies specific for grass pollen. All but one of the maize pollen-allergic subjects had suffered from allergic grass pollen-related symptoms for 6 to 11 years before job-related exposure to maize pollen. Lung function testing was normal in all cases. In immunoblot analyses, the allergenic components could be identified as Zea m 1 and Zea m 13. The reactivity is mostly caused by cross-reactivity to the homologous allergens in temperate grass pollen. Two sera responded to Zea m 3, but interestingly not to the corresponding timothy allergen indicating maize-specific IgE reactivity. Conclusion The present data suggest that subjects pollinating maize are at high risk of developing an allergy to maize pollen as a so far underestimated source of occupational allergens. For the screening of patients with suspected maize pollen sensitization, the determination of IgE antibodies specific for maize pollen is suitable. PMID:22165847

  10. Arabidopsis FIMBRIN5, an Actin Bundling Factor, Is Required for Pollen Germination and Pollen Tube Growth[W

    PubMed Central

    Wu, Youjun; Yan, Jin; Zhang, Ruihui; Qu, Xiaolu; Ren, Sulin; Chen, Naizhi; Huang, Shanjin

    2010-01-01

    Actin cables in pollen tubes serve as molecular tracks for cytoplasmic streaming and organelle movement and are formed by actin bundling factors like villins and fimbrins. However, the precise mechanisms by which actin cables are generated and maintained remain largely unknown. Fimbrins comprise a family of five members in Arabidopsis thaliana. Here, we characterized a fimbrin isoform, Arabidopsis FIMBRIN5 (FIM5). Our results show that FIM5 is required for the organization of actin cytoskeleton in pollen grains and pollen tubes, and FIM5 loss-of-function associates with a delay of pollen germination and inhibition of pollen tube growth. FIM5 decorates actin filaments throughout pollen grains and tubes. Actin filaments become redistributed in fim5 pollen grains and disorganized in fim5 pollen tubes. Specifically, actin cables protrude into the extreme tips, and their longitudinal arrangement is disrupted in the shank of fim5 pollen tubes. Consequently, the pattern and velocity of cytoplasmic streaming were altered in fim5 pollen tubes. Additionally, loss of FIM5 function rendered pollen germination and tube growth hypersensitive to the actin-depolymerizing drug latrunculin B. In vitro biochemical analyses indicated that FIM5 exhibits actin bundling activity and stabilizes actin filaments. Thus, we propose that FIM5 regulates actin dynamics and organization during pollen germination and tube growth via stabilizing actin filaments and organizing them into higher-order structures. PMID:21098731

  11. Selective deficiency of IgA

    MedlinePlus

    Consider genetic counseling if you have a family history of selective IgA deficiency and you plan to have children. If ... Genetic counseling may be of value to prospective parents with a family history of selective IgA deficiency.

  12. Evaluation of intra- and extra-epithelial secretory IgA in chlamydial infections

    PubMed Central

    Armitage, Charles W; O’Meara, Connor P; Harvie, Marina C G; Timms, Peter; Wijburg, Odilia L; Beagley, Kenneth W

    2014-01-01

    Immunoglobulin A is an important mucosal antibody that can neutralize mucosal pathogens by either preventing attachment to epithelia (immune exclusion) or alternatively inhibit intra-epithelial replication following transcytosis by the polymeric immunoglobulin receptor (pIgR). Chlamydia trachomatis is a major human pathogen that initially targets the endocervical or urethral epithelium in women and men, respectively. As both tissues contain abundant secretory IgA (SIgA) we assessed the protection afforded by IgA targeting different chlamydial antigens expressed during the extra- and intra-epithelial stages of infection. We developed an in vitro model using polarizing cells expressing the murine pIgR together with antigen-specific mouse IgA, and an in vivo model using pIgR−/− mice. Secretory IgA targeting the extra-epithelial chlamydial antigen, the major outer membrane protein, significantly reduced infection in vitro by 24% and in vivo by 44%. Conversely, pIgR-mediated delivery of IgA targeting the intra-epithelial inclusion membrane protein A bound to the inclusion but did not reduce infection in vitro or in vivo. Similarly, intra-epithelial IgA targeting the secreted protease Chlamydia protease-like activity factor also failed to reduce infection. Together, these data suggest the importance of pIgR-mediated delivery of IgA targeting extra-epithelial, but not intra-epithelial, chlamydial antigens for protection against a genital tract infection. PMID:24827556

  13. IgA mesangial deposits in C3H/HeJ mice after oral immunization with ferritin or bovine serum albumin.

    PubMed Central

    Genin, C; Laurent, B; Sabatier, J C; Colon, S; Berthoux, F C

    1986-01-01

    In order to study an experimental model of IgA nephropathy, C3H/HeJ mice which are high IgA responders were strongly immunized orally with ferritin and compared to syngeneic C3H/eB. C3H/HeJ exhibited a significant increase of total IgA level in the serum and of IgA deposits in the mesangium. However the low level of IgA antibody to ferritin detected in the serum and the unsuccessful search for ferritin and antibody to ferritin in the glomeruli suggest that strong oral immunization of C3H/HeJ mice leads to high level of non specific IgA in the serum and deposition of IgA in the kidney. Images Fig. 2 Fig. 3 PMID:3516467

  14. IgA nephropathy and infections.

    PubMed

    Rollino, Cristiana; Vischini, Gisella; Coppo, Rosanna

    2016-08-01

    In this paper we concentrate on the role of infections in IgA nephropathy both from a pathogenetic and clinic point of view. The current hypotheses as regards the role of infections in the pathogenesis of IgA nephropathy are: (a) role of particular pathogens, (b) chronic exposure to mucosal infections, (c) abnormal handling of commensal microbes (gut microbiota). We also focus on particular infections reported in association with classic IgA nephropathy (HIV, malaria, Chlamydia, Lyme disease), as well as on IgA dominant-infection-associated glomerulonephritis. This is a unique form of glomerulonephritis, where IgA deposition is dominant. It is mostly recognized in old, diabetic patients and in association with staphylococcal infection. PMID:26800970

  15. Cleavage of a Recombinant Human Immunoglobulin A2 (IgA2)-IgA1 Hybrid Antibody by Certain Bacterial IgA1 Proteases

    PubMed Central

    Senior, Bernard W.; Dunlop, James I.; Batten, Margaret R.; Kilian, Mogens; Woof, Jenny M.

    2000-01-01

    To understand more about the factors influencing the cleavage of immunoglobulin A1 (IgA1) by microbial IgA1 proteases, a recombinant human IgA2/IgA1 hybrid molecule was generated. In the hybrid, termed IgA2/A1 half hinge, a seven-amino-acid sequence corresponding to one half of the duplicated sequence making up the IgA1 hinge was incorporated into the equivalent site in IgA2. Insertion of the IgA1 half hinge into IgA2 did not affect antigen binding capacity or the functional activity of the hybrid molecule, as judged by its ability to bind to IgA Fcα receptors and trigger respiratory bursts in neutrophils. Although the IgA2/A1 hybrid contained only half of the IgA1 hinge, it was found to be cleaved by a variety of different bacterial IgA1 proteases, including representatives of those that cleave IgA1 in the different duplicated halves of the hinge, namely, those of Prevotella melaninogenica, Streptococcus pneumoniae, S. sanguis, Neisseria meningitidis types 1 and 2, N. gonorrhoeae types 1 and 2, and Haemophilus influenzae type 2. Thus, for these enzymes the recognition site for IgA1 cleavage is contained within half of the IgA1 hinge region; additional distal elements, if required, are provided by either an IgA1 or an IgA2 framework. In contrast, the IgA2/A1 hybrid appeared to be resistant to cleavage with S. oralis and some H. influenzae type 1 IgA1 proteases, suggesting these enzymes require additional determinants for efficient substrate recognition. PMID:10639405

  16. Cleavage of a recombinant human immunoglobulin A2 (IgA2)-IgA1 hybrid antibody by certain bacterial IgA1 proteases.

    PubMed

    Senior, B W; Dunlop, J I; Batten, M R; Kilian, M; Woof, J M

    2000-02-01

    To understand more about the factors influencing the cleavage of immunoglobulin A1 (IgA1) by microbial IgA1 proteases, a recombinant human IgA2/IgA1 hybrid molecule was generated. In the hybrid, termed IgA2/A1 half hinge, a seven-amino-acid sequence corresponding to one half of the duplicated sequence making up the IgA1 hinge was incorporated into the equivalent site in IgA2. Insertion of the IgA1 half hinge into IgA2 did not affect antigen binding capacity or the functional activity of the hybrid molecule, as judged by its ability to bind to IgA Fcalpha receptors and trigger respiratory bursts in neutrophils. Although the IgA2/A1 hybrid contained only half of the IgA1 hinge, it was found to be cleaved by a variety of different bacterial IgA1 proteases, including representatives of those that cleave IgA1 in the different duplicated halves of the hinge, namely, those of Prevotella melaninogenica, Streptococcus pneumoniae, S. sanguis, Neisseria meningitidis types 1 and 2, N. gonorrhoeae types 1 and 2, and Haemophilus influenzae type 2. Thus, for these enzymes the recognition site for IgA1 cleavage is contained within half of the IgA1 hinge region; additional distal elements, if required, are provided by either an IgA1 or an IgA2 framework. In contrast, the IgA2/A1 hybrid appeared to be resistant to cleavage with S. oralis and some H. influenzae type 1 IgA1 proteases, suggesting these enzymes require additional determinants for efficient substrate recognition. PMID:10639405

  17. Prevention of Birch Pollen-Related Food Allergy by Mucosal Treatment with Multi-Allergen-Chimers in Mice

    PubMed Central

    Hoflehner, Elisabeth; Hufnagl, Karin; Schabussova, Irma; Jasinska, Joanna; Hoffmann-Sommergruber, Karin; Bohle, Barbara; Maizels, Rick M.; Wiedermann, Ursula

    2012-01-01

    Background Among birch pollen allergic patients up to 70% develop allergic reactions to Bet v 1-homologue food allergens such as Api g 1 (celery) or Dau c 1 (carrot), termed as birch pollen-related food allergy. In most cases, specific immunotherapy with birch pollen extracts does not reduce allergic symptoms to the homologue food allergens. We therefore genetically engineered a multi-allergen chimer and tested if mucosal treatment with this construct could represent a novel approach for prevention of birch pollen-related food allergy. Methodology BALB/c mice were poly-sensitized with a mixture of Bet v 1, Api g 1 and Dau c 1 followed by a sublingual challenge with carrot, celery and birch pollen extracts. For prevention of allergy sensitization an allergen chimer composed of immunodominant T cell epitopes of Api g 1 and Dau c 1 linked to the whole Bet v 1 allergen, was intranasally applied prior to sensitization. Results Intranasal pretreatment with the allergen chimer led to significantly decreased antigen-specific IgE-dependent β-hexosaminidase release, but enhanced allergen-specific IgG2a and IgA antibodies. Accordingly, IL-4 levels in spleen cell cultures and IL-5 levels in restimulated spleen and cervical lymph node cell cultures were markedly reduced, while IFN-γ levels were increased. Immunomodulation was associated with increased IL-10, TGF-β and Foxp3 mRNA levels in NALT and Foxp3 in oral mucosal tissues. Treatment with anti-TGF-β, anti-IL10R or anti-CD25 antibodies abrogated the suppression of allergic responses induced by the chimer. Conclusion Our results indicate that mucosal application of the allergen chimer led to decreased Th2 immune responses against Bet v 1 and its homologue food allergens Api g 1 and Dau c 1 by regulatory and Th1-biased immune responses. These data suggest that mucosal treatment with a multi-allergen vaccine could be a promising treatment strategy to prevent birch pollen-related food allergy. PMID:22768077

  18. Influence of Pollen Nutrition on Honey Bee Health: Do Pollen Quality and Diversity Matter?

    PubMed Central

    Di Pasquale, Garance; Salignon, Marion; Le Conte, Yves; Belzunces, Luc P.; Decourtye, Axel; Kretzschmar, André; Suchail, Séverine; Brunet, Jean-Luc; Alaux, Cédric

    2013-01-01

    Honey bee colonies are highly dependent upon the availability of floral resources from which they get the nutrients (notably pollen) necessary to their development and survival. However, foraging areas are currently affected by the intensification of agriculture and landscape alteration. Bees are therefore confronted to disparities in time and space of floral resource abundance, type and diversity, which might provide inadequate nutrition and endanger colonies. The beneficial influence of pollen availability on bee health is well-established but whether quality and diversity of pollen diets can modify bee health remains largely unknown. We therefore tested the influence of pollen diet quality (different monofloral pollens) and diversity (polyfloral pollen diet) on the physiology of young nurse bees, which have a distinct nutritional physiology (e.g. hypopharyngeal gland development and vitellogenin level), and on the tolerance to the microsporidian parasite Nosemaceranae by measuring bee survival and the activity of different enzymes potentially involved in bee health and defense response (glutathione-S-transferase (detoxification), phenoloxidase (immunity) and alkaline phosphatase (metabolism)). We found that both nurse bee physiology and the tolerance to the parasite were affected by pollen quality. Pollen diet diversity had no effect on the nurse bee physiology and the survival of healthy bees. However, when parasitized, bees fed with the polyfloral blend lived longer than bees fed with monofloral pollens, excepted for the protein-richest monofloral pollen. Furthermore, the survival was positively correlated to alkaline phosphatase activity in healthy bees and to phenoloxydase activities in infected bees. Our results support the idea that both the quality and diversity (in a specific context) of pollen can shape bee physiology and might help to better understand the influence of agriculture and land-use intensification on bee nutrition and health. PMID:23940803

  19. Isolated lymphoid follicles are not IgA inductive sites for recombinant Salmonella

    SciTech Connect

    Hashizume, Tomomi; Momoi, Fumiki; Kurita-Ochiai, Tomoko; Kaminogawa, Shuichi; Hosono, Akira; Kataoka, Kosuke; Shinozaki-Kuwahara, Noriko; Kweon, Mi-Na; Yamamoto, Masafumi . E-mail: yamamoto.masafumi@nihon-u.ac.jp

    2007-08-24

    In this study, we investigated whether isolated lymphoid follicles (ILF) play a role in the regulation of intestinal IgA antibody (Ab) responses. The transfer of wild type (WT) bone marrow (BM) to lymphotoxin-{alpha}-deficient (LT{alpha}{sup -/-}) mice resulted in the formation of mature ILF containing T cells, B cells, and FDC clusters in the absence of mesenteric lymph nodes and Peyer's patches. Although the ILF restored total IgA Abs in the intestine, antigen (Ag)-specific IgA responses were not induced after oral immunization with recombinant Salmonella expressing fragment C of tetanus toxin. Moreover, Ag-specific cell proliferation was not detected in the ILF. Interestingly, no IgA anti-LPS Abs were detected in the fecal extracts of LT{alpha}{sup -/-} mice reconstituted with WT BM. On the basis of these findings, ILF can be presumed to play a role in the production of IgA Abs, but lymphoid nodules are not inductive sites for the regulation of Ag-specific intestinal IgA responses to recombinant Salmonella.

  20. Dating Fossil Pollen: A Simulation.

    ERIC Educational Resources Information Center

    Sheridan, Philip

    1992-01-01

    Describes a hands-on simulation in which students determine the age of "fossil" pollen samples based on the pollen types present when examined microscopically. Provides instructions for the preparation of pollen slides. (MDH)

  1. Serum and salivary IgA antibody responses to Saccharomyces cerevisiae, Candida albicans and Streptococcus mutans in orofacial granulomatosis and Crohn's disease.

    PubMed

    Savage, N W; Barnard, K; Shirlaw, P J; Rahman, D; Mistry, M; Escudier, M P; Sanderson, J D; Challacombe, S J

    2004-03-01

    Orofacial granulomatosis (OFG) is a condition of unknown aetiology with histological and, in some cases, clinical association with Crohn's disease (CD). However, the exact relationship between OFG and CD remains uncertain. The aim of this study was to determine whether OFG could be distinguished immunologically from CD by comparing non-specific and specific aspects of humoral immunity in serum, whole saliva and parotid saliva in three groups of patients: (a) OFG only (n = 14), (b) those with both oral and gut CD (OFG + CD) (n = 12) and (c) CD without oral involvement (n = 22) and in healthy controls (n = 29). Non-specific immunoglobulin (IgA, SigA, IgA subclasses and IgG) levels and antibodies to whole cells of Saccharomyces cerevisiae, Candida albicans and Streptococcus mutans were assayed by enzyme-linked immunosorbent assay (ELISA) in serum, whole saliva and parotid saliva. Serum IgA and IgA1 and IgA2 subclasses were raised in all patient groups (P < 0.01). Salivary IgA (and IgG) levels were raised in OFG and OFG + CD (P < 0.01) but not in the CD group. Parotid IgA was also raised in OFG and OFG + CD but not in CD. The findings suggest that serum IgA changes reflect mucosal inflammation anywhere in the GI tract but that salivary IgA changes reflect involvement of the oral cavity. Furthermore, the elevated levels of IgA in parotid saliva suggest involvement of the salivary glands in OFG. Serum IgA antibodies to S. cerevisiae were raised markedly in the two groups with gut disease while serum IgA (or IgG) antibodies to C. albicans were elevated significantly in all three patient groups (P < 0.02). No differences were found with antibodies to S. mutans. Whole saliva IgA antibodies to S. cerevisiae (and C. albicans) were raised in the groups with oral involvement. These findings suggest that raised serum IgA antibodies to S. cerevisiae may reflect gut inflammation while raised SIgA antibodies to S. cerevisiae or raised IgA or IgA2 levels in saliva reflect oral but

  2. Blood Test: Immunoglobulin A (IgA)

    MedlinePlus

    ... Melon Smoothie Pregnant? Your Baby's Growth Blood Test: Immunoglobulin A (IgA) KidsHealth > For Parents > Blood Test: Immunoglobulin ... of immunoglobulin A, one of the most common antibodies in the body. Antibodies are proteins made by ...

  3. Allergies, asthma, and pollen

    MedlinePlus

    ... Some trees Some grasses Weeds Ragweed Watch the weather and the season The amount of pollen in the air can affect whether you or your child has hay fever and asthma symptoms. On hot, dry, windy days, more pollen is in the air. ...

  4. Characterization of the ligand binding site of the bovine IgA Fc receptor (bFc alpha R).

    PubMed

    Morton, H Craig; Pleass, Richard J; Woof, Jenny M; Brandtzaeg, Per

    2004-12-24

    Recently, we identified a bovine IgA Fc receptor (bFc alpha R), which shows high homology to the human myeloid Fc alpha R, CD89. IgA binding has previously been shown to depend on several specific residues located in the B-C and F-G loops of the membrane-distal extracellular domain 1 of CD89. To compare the ligand binding properties of these two Fc alpha Rs, we have mapped the IgA binding site of bFc alpha R. We show that, in common with CD89, Tyr-35 in the B-C loop is essential for IgA binding. However, in contrast to earlier observations on CD89, mutation of residues in the F-G loop did not significantly inhibit IgA binding. PMID:15485844

  5. PECTIN METHYLESTERASE48 is involved in Arabidopsis pollen grain germination.

    PubMed

    Leroux, Christelle; Bouton, Sophie; Kiefer-Meyer, Marie-Christine; Fabrice, Tohnyui Ndinyanka; Mareck, Alain; Guénin, Stéphanie; Fournet, Françoise; Ringli, Christoph; Pelloux, Jérôme; Driouich, Azeddine; Lerouge, Patrice; Lehner, Arnaud; Mollet, Jean-Claude

    2015-02-01

    Germination of pollen grains is a crucial step in plant reproduction. However, the molecular mechanisms involved remain unclear. We investigated the role of PECTIN METHYLESTERASE48 (PME48), an enzyme implicated in the remodeling of pectins in Arabidopsis (Arabidopsis thaliana) pollen. A combination of functional genomics, gene expression, in vivo and in vitro pollen germination, immunolabeling, and biochemical analyses was used on wild-type and Atpme48 mutant plants. We showed that AtPME48 is specifically expressed in the male gametophyte and is the second most expressed PME in dry and imbibed pollen grains. Pollen grains from homozygous mutant lines displayed a significant delay in imbibition and germination in vitro and in vivo. Moreover, numerous pollen grains showed two tips emerging instead of one in the wild type. Immunolabeling and Fourier transform infrared analyses showed that the degree of methylesterification of the homogalacturonan was higher in pme48-/- pollen grains. In contrast, the PME activity was lower in pme48-/-, partly due to a reduction of PME48 activity revealed by zymogram. Interestingly, the wild-type phenotype was restored in pme48-/- with the optimum germination medium supplemented with 2.5 mm calcium chloride, suggesting that in the wild-type pollen, the weakly methylesterified homogalacturonan is a source of Ca(2+) necessary for pollen germination. Although pollen-specific PMEs are traditionally associated with pollen tube elongation, this study provides strong evidence that PME48 impacts the mechanical properties of the intine wall during maturation of the pollen grain, which, in turn, influences pollen grain germination. PMID:25524442

  6. Estimates of common ragweed pollen emission and dispersion over Europe using RegCM-pollen model

    NASA Astrophysics Data System (ADS)

    Liu, L.; Solmon, F.; Vautard, R.; Hamaoui-Laguel, L.; Torma, Cs. Zs.; Giorgi, F.

    2015-11-01

    Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic and invasive plant in Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hayfever and asthma (D'Amato et al., 2007; Burbach et al., 2009). To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model (RegCM) version 4 using the framework of the Community Land Model (CLM) version 4.5. In the online model environment where climate is integrated with dispersion and vegetation production, pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period 2000-2010. To reduce the large uncertainties notably due to ragweed density distribution on pollen emission, a calibration based on airborne pollen observations is used. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain 68.6, 39.2, and 34.3 % of the observed variance in starting, central, and ending dates of the pollen season with associated root mean square error (RMSE) equal to 4.7, 3.9, and 7.0 days, respectively. The correlation between simulated and observed daily concentrations time series reaches 0.69. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger. From these simulations health risks associated common ragweed pollen spread are then evaluated through calculation of exposure time above health

  7. Grass Pollen Allergens

    PubMed Central

    Augustin, Rosa; Hayward, Barbara J.

    1962-01-01

    Cocksfoot and Timothy pollen extracts are each found to contain at least fifteen components antigenic in rabbits. Most of these can also be allergens for man, but only a few are regularly so. These `principal' allergens have now been isolated in highly purified form. Procedures are given for a simple method of preparing extracts for clinical purposes and for the partial separation, concentration and purification of the allergens by means of differential extractions of the pollens and by means of ultrafiltration, isoelectric precipitation and salt fractionations (at acid and neutral pH) of the extracts. Isoelectric precipitations gave highly pigmented acid complexes, two of which moved as single sharp peaks at pH 7.4 in free electrophoresis, but proved to be hardly active by skin tests. Acid NaCl fractionation of the remainder resulted for Cocksfoot and Timothy in the isolation of a nearly white powder (T21.111121112 = T21B) which was weight for weight 1000–10,000 times as active as the pollen from which it had been derived. The powders have retained their activity for 7 years. By gel diffusion tests, they were found to contain two antigens (one in each preparation) which were immunologically partially related, but the Timothy preparation contained in addition the `innermost' `twin' antigens specific for Timothy that we had discovered previously in the crude extracts by gel diffusion methods. Skin reactions could be elicited in hay-fever subjects by prick tests with concentrations of 10-9–10-8 g./ml., which is equivalent to intradermal injections of 10-11–10-10 mg. and represents a 300-fold purification with respect to the concentrates of crude pollen extracts prepared by ultrafiltration and dialysis. Fractionation on DEAE-cellulose of one of the highly purified Timothy preparations (T21.11112112 = T21A) and other, crude Timothy and Cocksfoot extracts resulted in considerable and reproducible separation of the various antigens, with no indication of the

  8. Frequency of IgA antibodies in pemphigus, bullous pemphigoid and mucous membrane pemphigoid.

    PubMed

    Cozzani, Emanuele; Drosera, Massimo; Parodi, Aurora; Carrozzo, Marco; Gandolfo, Sergio; Rebora, Alfredo

    2004-01-01

    Circulating and bound IgA antibodies can be found in the autoimmune blistering diseases, but their prevalence, clinical relevance and target antigens remain unknown. Thirty-two patients with pemphigus, 73 with bullous pemphigoid and 28 with mucous membrane pemphigoid were studied retrospectively. Direct immunofluorescence (DIF) analysis of IgG, IgA, IgM and C3 was carried out for all cases. Sera were studied by standard indirect immunofluorescence, indirect immunofluorescence on salt-split skin, immunoblotting for bullous pemphigoid and mucous membrane pemphigoid and ELISA for pemphigus. With DIF, we found IgA autoantibodies in 22 of all 133 cases. Circulating IgA antibodies to skin were detected in 2 of 3 IgA-DIF-positive patients with pemphigus, in 3 of 6 with bullous pemphigoid, and in 6 of 13 with mucous membrane pemphigoid. We confirm that the IgA reactivity is more frequently associated with mucous membrane involvement, especially in cases without critical involvement (5/8). The role of IgA and its antigenic specificity in these diseases remain unclear. PMID:15370705

  9. POLLEN TUBE LOCALIZATION IMPLIES A ROLE IN POLLEN-PISTIL INTERACTIONS FOR THE TOMATO RECEPTOR-LIKE PROTEIN KINASES LEPRK1 AND LEPRK2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We screened for pollen-specific kinase genes, which are potential signal transduction components of pollen-pistil interactions, and isolated two structurally related receptor-like kinases RLKs from tomato, LePRK1 and LePRK2. These kinases are similar to a pollen-expressed RLK from petunia, but they ...

  10. Markers for the progression of IgA nephropathy.

    PubMed

    Maixnerova, Dita; Reily, Colin; Bian, Qi; Neprasova, Michaela; Novak, Jan; Tesar, Vladimir

    2016-08-01

    We have summarized the latest findings on markers for progression of immunoglobulin A (IgA) nephropathy (IgAN), the most common primary glomerulonephritis with a high prevalence among end-stage renal disease (ESRD) patients. The clinical predictors of renal outcome in IgAN nephropathy, such as proteinuria, hypertension, and decreased estimated glomerular filtration rate (eGFR) at the time of the diagnosis, are well known. The Oxford classification of IgAN identified four types of histological lesions (known as the MEST score) associated with the development of ESRD and/or a 50 % reduction in eGFR. In addition, the role of genetic risk factors associated with IgAN is being elucidated by genome-wide association studies, with multiple risk alleles described. Recently, biomarkers in serum (galactose-deficient IgA1, IgA/IgG autoantibodies against galactose-deficient IgA1, and soluble CD 89-IgA complexes) and urine (soluble transferrin receptor, interleukin-6/epidermal growth factor ratio, fractalkine, laminin G-like 3 peptide, κ light chains, and mannan-binding lectin) have been identified. Some of these biomarkers may represent candidates for the development of noninvasive diagnostic tests, that would be useful for detection of subclinical disease activity, monitoring disease progression, assessment of treatment, and at the same time circumventing the complications associated with renal biopsies. These advances, along with future disease-specific therapy, will be helpful in improving the treatment effectiveness, prognosis, and the quality of life in connection with IgAN. PMID:27142988

  11. Hypersensitivity to common tree pollens in New York City patients.

    PubMed

    Lin, Robert Y; Clauss, Allison E; Bennett, Edward S

    2002-01-01

    Testing for tree pollen hypersensitivity typically requires the use of several tree pollens. Identifying patterns of cross-sensitivity to tree pollens could reduce the number of trees used for testing. The goal of this study was to relate reported tree pollen levels to hypersensitivity patterns. Three hundred seventy-one allergy patients were tested serologically for hypersensitivity toward prevalent tree pollens in the surrounding New York area over the years 1993-2000. Specific tree pollens that were examined included oak (Quercus alba), birch (Betula verrucosa), beech (Fagus grandifolia), poplar (Populus deltoides), maple (Acer negundo), ash (Fraxinus americana), hickory (Carya pecan), and elm (Ulmus americana). Statistical analysis of the levels of hypersensitivity was performed to identify correlations and grouping factors. Pollen levels, obtained from published annual pollen and spore reports, were characterized and related to the prevalence of hypersensitivity for the various trees. The highest prevalence of hypersensitivity (score > or = class 1) was for oak (34.3%), birch (32.9%), and maple (32.8%) tree pollens. Lower prevalences were observed for beech (29.6%), hickory (27.1%), ash (26%), elm (24.6%), and poplar (20.6%) trees. Significant correlations were observed between oak, birch, and beech radioallergosorbent test scores. Factor analysis identified two independent pollen groups with oak, birch, and beech consisting of one group and the other five tree pollens constituting the other group. Peak pollen counts clearly were highest for oak, birch, and maple trees. The peak pollen counts corresponded roughly to seropositivity prevalences for the tree pollens. When elm, poplar, and beech test scores were not used to identify patients who were allergic to tree pollens, only 1 of 106 patients with any positive tree radioallergosorbent test score was missed. It is concluded that in the New York City area, hypersensitivity to tree pollens most often is

  12. Specialist pollinators deplete pollen in the spring ephemeral wildflower Claytonia virginica.

    PubMed

    Parker, Alison J; Williams, Neal M; Thomson, James D

    2016-08-01

    Pollinators that collect pollen - and specifically, pollen-specialist bees - are often considered to be the best pollinators of a (host) plant. Although pollen collectors and pollen specialists often benefit host plants, especially in the pollen that they deliver (their pollination "effectiveness"), they can also exact substantial costs because they are motivated to collect as much pollen as possible, reducing the proportion of pollen removed that is subsequently delivered to stigmas (their pollination "efficiency"). From the plant perspective, pollen grains that do not pollinate conspecific stigmas are "wasted", and potentially costly. We measured costs and benefits of nectar-collecting, pollen-collecting, and pollen-specialist pollinator visitation to the spring ephemeral Claytonia virginica. Visits by the pollen-specialist bee Andrena erigeniae depleted pollen quickly and thoroughly. Although all pollinators delivered roughly the same number of grains, the pollen specialist contributed most to C. virginica pollen delivery because of high visitation rates. However, the pollen specialist also removed a large number of grains; this removal may be especially costly because it resulted in the depletion of pollen grains in C. virginica populations. While C. virginica appears to rely on pollen transfer by the pollen specialist in these populations, nectar-collecting visitors could provide the same benefit at a lower cost if their visitation rates increased. Pollen depletion affects a pollinator's value to plants, but is frequently overlooked. If they lower the effectiveness of future floral visitors, visits by A. erigeniae females to C. virginica may be more detrimental than beneficial compared to other pollinators and may, in some circumstances, reduce plant fitness rather than increase it. Therefore, A. erigeniae and C. virginica may vary in their degree of mutualism depending on the ecological context. PMID:27551374

  13. Cell-Cell Interactions during pollen tube guidance

    SciTech Connect

    Daphne Preuss

    2009-03-31

    The long-term goal of this research is to identify the signaling molecules that mediate plant cell-cell interactions during pollination. The immediate goals of this project are to perform genetic and molecular analysis of pollen tube guidance. Specifically, we proposed to: 1. Characterize the pistil components that direct pollen tube navigation using the Arabidopsis thaliana in vitro pollen tube guidance system 2. Identify pistil signals that direct pollen tube guidance by a) using microarrays to profile gene expression in developing pistils, and b) employing proteomics and metabolomics to isolate pollen tube guidance signals. 3. Explore the genetic basis of natural variation in guidance signals, comparing the in vitro interactions between pollen and pistils from A. thaliana and its close relatives.

  14. Occupational Allergy to Peach (Prunus persica) Tree Pollen and Potential Cross-Reactivity between Rosaceae Family Pollens.

    PubMed

    Jiang, Nannan; Yin, Jia; Mak, Philip; Wen, Liping

    2015-10-01

    Orchard workers in north China are highly exposed to orchard pollens, especially peach and other Rosaceae family pollens during pollination season. The aim of this study was to investigate whether occupational allergy to peach tree pollen as a member of Rosaceae family is IgE-mediated and to evaluate the cross-reactivity among Rosaceae family pollens. Allergen skin test and conjunctival challenge test were performed; enzyme linked immune-sorbent assay (ELISA), inhibiting ELISA, western immunoblotting and inhibiting western immunoblotting were done with Rosaceae family orchard pollens, including peach, apricot, cherry, apple and pear tree pollens. Mass spectrometry was also performed to probe the main allergen component and cross-reactive protein. Sensitizations to peach pollen were found in both skin test and conjunctival challenge in the patients. Serum specific IgE to three pollens (peach, apricot and cherry) were detected through ELISA. When peach pollen used as solid phase, ELISA inhibition revealed other four kinds of pollens capable of inducing partial to strong inhibitions (45% to 87%), with the strongest inhibition belonging to apricot pollen (87%). Western blotting showed predominant IgE binding to a 20 KD protein among these pollens, which appeared to be a cross-reactive allergen component through western blotting inhibition. It was recognized as a protein homologous to glutathione s-transferase 16 from Arabidopsis thaliana. Peach and other Rosaceae family tree pollen may serve as a potential cause of IgE mediated occupational respiratory disease in orchard workers in north China. PMID:26742437

  15. TGF-β1 improves mucosal IgA dysfunction and dysbiosis following intestinal ischaemia-reperfusion in mice.

    PubMed

    Zhang, Xu-Yu; Liu, Zi-Meng; Zhang, Hu-Fei; Li, Yun-Sheng; Wen, Shi-Hong; Shen, Jian-Tong; Huang, Wen-Qi; Liu, Ke-Xuan

    2016-06-01

    Intestinal ischaemia/reperfusion (I/R) severely disrupts gut barriers and leads to high mortality in the critical care setting. Transforming growth factor (TGF)-β1 plays a pivotal role in intestinal cellular and immune regulation. However, the effects of TGF-β1 on intestinal I/R injury remain unclear. Thus, we aimed to investigate the effects of TGF-β1 on gut barriers after intestinal I/R and the molecular mechanisms. Intestinal I/R model was produced in mice by clamping the superior mesenteric artery for 1 hr followed by reperfusion. Recombinant TGF-β1 was intravenously infused at 15 min. before ischaemia. The results showed that within 2 hrs after reperfusion, intestinal I/R disturbed intestinal immunoglobulin A class switch recombination (IgA CSR), the key process of mucosal IgA synthesis, and resulted in IgA dysfunction, as evidenced by decreased production and bacteria-binding capacity of IgA. Meanwhile, the disruptions of intestinal microflora and mucosal structure were exhibited. Transforming growth factor-β1 activated IgA CSR as evidenced by the increased activation molecules and IgA precursors. Strikingly, TGF-β1 improved intestinal mucosal IgA dysfunction, dysbiosis and epithelial damage at the early stage after reperfusion. In addition, SB-431542, a specific inhibitor of activating mothers against decapentaplegic homologue (SMAD) 2/3, totally blocked the inductive effect of TGF-β1 on IgA CSR and almost abrogated the above protective effects on intestinal barriers. Taken together, our study demonstrates that TGF-β1 protects intestinal mucosal IgA immunity, microbiota and epithelial integrity against I/R injury mainly through TGF-β receptor 1/SMAD 2/3 pathway. Induction of IgA CSR may be involved in the protection conferred by TGF-β1. PMID:26820382

  16. Spontaneous expression of a low affinity Fc receptor for IgA (Fc alpha R) on human B cell lines.

    PubMed Central

    Millet, I; Briere, F; Vincent, C; Rousset, F; Andreoni, C; De Vries, J E; Revillard, J P

    1989-01-01

    Expression of receptors for IgA (Fc alpha Rs) was investigated on a panel of 35 human B cell lines by labelling with human secretory IgA (0.5 mg/ml) and flow cytometry analysis after staining with fluoresceinated goat anti-human secretory component and/or anti-alpha chain F(ab')2 fragments. Receptors for IgA could be demonstrated on one out of nine Burkitt's lymphoma cell lines, three out of five myeloma cell lines and five out of 21 lymphoblastoid cell lines. The percentage of Fc alpha R-positive cells within the same B cell line varied upon repeated examination. Human dimeric IgA1 lambda myeloma protein revealed the same number of IgA receptor positive cells as did secretory IgA, whereas monomeric IgA did not bind to Fc alpha R. Detection of Fc alpha R was not inhibited when the tests were carried out in the presence of human dimeric IgG, IgM, asialo-orosomucoid, and secretory component but it was abrogated by pre-treatment of the cells with trypsin. The binding characteristics of Fc alpha Rs were studied on the myeloma cell line Esteve, using 125I-labelled human dimeric IgA and secretory IgA. The binding was dose-dependent with rapid kinetics and specific inhibition by unlabelled secretory IgA. Scatchard plot analysis resulted in an equilibrium constant K ranging from 3.2 to 4.7 x 10(6) M/l. No correlation was observed between Fc alpha R expression and differentiation stage, monoclonality, polyclonality of the cell lines, or Ig class produced by the B cells. PMID:2788048

  17. [Hypersensitivity to pollen of Olea europea in patients with pollen allergy in Zadar County, Croatia].

    PubMed

    Skitarelić, Natasa; Mazzi, Antun; Skitarelić, Neven; Misulić, Josko; Vuletić, Ana

    2010-06-01

    Olive pollen is one of the most common respiratory allergens in the Mediterranean countries. The aim of this study was to establish the frequency of hypersensitivity to the pollen of Olea europea in pollen allergic patients in the County of Zadar. The study included 671 patients with pollen allergy; 61 % were male and 39 % female. 53.5 % were children aged from 4 to 14 years and 46.5 % adolescents and adults from 15 to 59 years. We took their case history, clinically examined them, and tested using the skin prick test and enzymo-immunologic UniCAP test for specific IgE antibodies. For statistical analysis we used the chi-square test. Hypersensitivity to Olea europea pollen was confirmed in 8.8 % patients with pollen allergy. Among them, the most prevalent symptom was rhinitis (58 %). Most hypersensitive patients were urban residents. Only 3 % patients lived on an island. Judging by available data, our findings show the lowest hypersensitivity to olive pollen in the Mediterranean. A comparison with our two earlier studies did not show any fluctuation in this kind of hypersensitivity. PMID:20587396

  18. Binding and transepithelial transport of immunoglobulins by intestinal M cells: demonstration using monoclonal IgA antibodies against enteric viral proteins

    SciTech Connect

    Weltzin, R.; Lucia-Jandris, P.; Michetti, P.; Fields, B.N.; Kraehenbuhl, J.P.; Neutra, M.R.

    1989-05-01

    M cells of intestinal epithelia overlying lymphoid follicles endocytose luminal macromolecules and microorganisms and deliver them to underlying lymphoid tissue. The effect of luminal secretory IgA antibodies on adherence and transepithelial transport of antigens and microorganisms by M cells is unknown. We have studied the interaction of monoclonal IgA antibodies directed against specific enteric viruses, or the hapten trinitrophenyl (TNP), with M cells. To produce monospecific IgA antibodies against mouse mammary tumor virus (MMTV) and reovirus type 1, Peyer's patch cells from mucosally immunized mice were fused with myeloma cells, generating hybridomas that secreted virus-specific IgA antibodies in monomeric and polymeric forms. One of two anti-MMTV IgA antibodies specifically bound the viral surface glycoprotein gp52, and 3 of 10 antireovirus IgA antibodies immunoprecipitated sigma 3 and mu lc surface proteins. 35S-labeled IgA antibodies injected intravenously into rats were recovered in bile as higher molecular weight species, suggesting that secretory component had been added on passage through the liver. Radiolabeled or colloidal gold-conjugated mouse IgA was injected into mouse, rat, and rabbit intestinal loops containing Peyer's patches. Light microscopic autoradiography and EM showed that all IgA antibodies (antivirus or anti-TNP) bound to M cell luminal membranes and were transported in vesicles across M cells. IgA-gold binding was inhibited by excess unlabeled IgA, indicating that binding was specific. IgG-gold also adhered to M cells and excess unlabeled IgG inhibited IgA-gold binding; thus binding was not isotype-specific. Immune complexes consisting of monoclonal anti-TNP IgA and TNP-ferritin adhered selectively to M cell membranes, while TNP-ferritin alone did not.

  19. A DNA barcoding approach to characterize pollen collected by honeybees.

    PubMed

    Galimberti, Andrea; De Mattia, Fabrizio; Bruni, Ilaria; Scaccabarozzi, Daniela; Sandionigi, Anna; Barbuto, Michela; Casiraghi, Maurizio; Labra, Massimo

    2014-01-01

    In the present study, we investigated DNA barcoding effectiveness to characterize honeybee pollen pellets, a food supplement largely used for human nutrition due to its therapeutic properties. We collected pollen pellets using modified beehives placed in three zones within an alpine protected area (Grigna Settentrionale Regional Park, Italy). A DNA barcoding reference database, including rbcL and trnH-psbA sequences from 693 plant species (104 sequenced in this study) was assembled. The database was used to identify pollen collected from the hives. Fifty-two plant species were identified at the molecular level. Results suggested rbcL alone could not distinguish among congeneric plants; however, psbA-trnH identified most of the pollen samples at the species level. Substantial variability in pollen composition was observed between the highest elevation locality (Alpe Moconodeno), characterized by arid grasslands and a rocky substrate, and the other two sites (Cornisella and Ortanella) at lower altitudes. Pollen from Ortanella and Cornisella showed the presence of typical deciduous forest species; however in samples collected at Ortanella, pollen of the invasive Lonicera japonica, and the ornamental Pelargonium x hortorum were observed. Our results indicated pollen composition was largely influenced by floristic local biodiversity, plant phenology, and the presence of alien flowering species. Therefore, pollen molecular characterization based on DNA barcoding might serve useful to beekeepers in obtaining honeybee products with specific nutritional or therapeutic characteristics desired by food market demands. PMID:25296114

  20. A DNA Barcoding Approach to Characterize Pollen Collected by Honeybees

    PubMed Central

    Bruni, Ilaria; Scaccabarozzi, Daniela; Sandionigi, Anna; Barbuto, Michela; Casiraghi, Maurizio; Labra, Massimo

    2014-01-01

    In the present study, we investigated DNA barcoding effectiveness to characterize honeybee pollen pellets, a food supplement largely used for human nutrition due to its therapeutic properties. We collected pollen pellets using modified beehives placed in three zones within an alpine protected area (Grigna Settentrionale Regional Park, Italy). A DNA barcoding reference database, including rbcL and trnH-psbA sequences from 693 plant species (104 sequenced in this study) was assembled. The database was used to identify pollen collected from the hives. Fifty-two plant species were identified at the molecular level. Results suggested rbcL alone could not distinguish among congeneric plants; however, psbA-trnH identified most of the pollen samples at the species level. Substantial variability in pollen composition was observed between the highest elevation locality (Alpe Moconodeno), characterized by arid grasslands and a rocky substrate, and the other two sites (Cornisella and Ortanella) at lower altitudes. Pollen from Ortanella and Cornisella showed the presence of typical deciduous forest species; however in samples collected at Ortanella, pollen of the invasive Lonicera japonica, and the ornamental Pelargonium x hortorum were observed. Our results indicated pollen composition was largely influenced by floristic local biodiversity, plant phenology, and the presence of alien flowering species. Therefore, pollen molecular characterization based on DNA barcoding might serve useful to beekeepers in obtaining honeybee products with specific nutritional or therapeutic characteristics desired by food market demands. PMID:25296114

  1. Overexpression of the tomato pollen receptor kinase LePRK1 rewires pollen tube growth to a blebbling mode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane–localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP...

  2. Studies of genetic transformation of higher plants using irradiated pollen

    SciTech Connect

    Chyi, Y.S.

    1984-01-01

    Pandey has reported extensively on an unusual genetic phenomenon he called egg transformation. When compatible pollen was treated wth genetically lethal dosage of ..gamma..-radiation (100,000 rad), and used as mentor pollen to overcome selfincompatibility of several Nicotiana species, some genetic characters were found to be transferred from the radiation killed pollen to nonhybrid progeny. Observed transformants were fertile, cytogenetically normal, and had maternal phenotypes except for those specific traits transferred from the donors. Heavily irradiated pollen was believed to discharge its radiation-fragmented DNA (chromatin) into the embryo sac and bring about the transformation of the egg. The frequency of gene transfer was reported to be over 50%, and happened for all three characters Pandey studied - self incompatible specificities, flower color, and pollen color. Plant species studied were tomato, pea, apple, rapeseed, and Nicotiana species, including various stocks from Dr. Pandey. Treatments included pollinations with soley irradiated donor pollen, with a mixture of irradiated donor and normal self pollen, with a mixture of normal donor and self pollen, and double pollinations with irradiated donor pollen and normal self pollen, using different time intervals to separate the two pollinations. A total of 6210 pollinations were made, and 17,522 seedlings representing 87,750 potential transformational events were screened. In no case was an unambiguous transformant recovered. This research was unable to confirm or expand upon the findings of Dr. Pandey, or elucidate the mechanisms underlying such phenomena. Alternative explanations for Pandey's data were postulated. This approach to gene transfer by using irradiated pollen appears to be of little practical use to plant breeders.

  3. Nephrotic syndrome is a rare manifestation of IGA nephropathy

    PubMed Central

    Alshomar, Ahmad A

    2016-01-01

    Nephrotic syndrome is a rare presentation of IgA nephropathy. The degree of proteinuria in IgA nephropathy predicts poor prognosis. We herein report a teenager with IGA nephropathy, the nephrotic syndrome and segmental glomerular scars who after developing complications from high dose corticosteroid therapy was successfully treated with tacrolimus and low dose prednisone. PMID:27610069

  4. Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination

    PubMed Central

    Rejón, Juan D.; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J.

    2012-01-01

    Background and Aims A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. Methods The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Key Results Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. Conclusions In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of

  5. Cloning and structural analysis of two highly divergent IgA isotypes, IgA1 and IgA2 from the duck billed platypus, Ornithorhynchus anatinus.

    PubMed

    Vernersson, M; Belov, K; Aveskogh, M; Hellman, L

    2010-01-01

    To trace the emergence of modern IgA isotypes during vertebrate evolution we have studied the immunoglobulin repertoire of a model monotreme, the platypus. Two highly divergent IgA-like isotypes (IgA1 and IgA2) were identified and their primary structures were determined from full-length cDNAs. A comparative analysis of the amino acid sequences for IgA from various animal species showed that the two platypus IgA isotypes form a branch clearly separated from their eutherian (placental) counterparts. However, they still conform to the general structure of eutherian IgA, with a hinge region and three constant domains. This indicates that the deletion of the second domain and the formation of a hinge region in IgA did occur very early during mammalian evolution, more than 166 million years ago. The two IgA isotypes in platypus differ in primary structure and appear to have arisen from a very early gene duplication, possibly preceding the metatherian eutherian split. Interestingly, one of these isotypes, IgA1, appears to be expressed in only the platypus, but is present in the echidna based on Southern blot analysis. The platypus may require a more effective mucosal immunity, with two highly divergent IgA forms, than the terrestrial echidna, due to its lifestyle, where it is exposed to pathogens both on land and in the water. PMID:19913303

  6. Pollen Viability and Pollen Tube Attrition in Cranberry (Vaccinium macrocarpon)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The content of mature seed in a cranberry fruit increases with stigmatic pollen load. On average, however, only two seeds result for every tetrad of pollen deposited. What then is the fate of the two remaining pollen grains fused in each tetrad? Germination in vitro revealed that most of the grains ...

  7. [IgA deficiency and Addison's disease].

    PubMed

    Petite, J

    1982-01-30

    A case of Addison's disease and selective IgA deficiency in a 15-year-old male is discussed. The etiology of Addison's disease in this case is unknown. Investigation of HLA-antigens in the family does not yield the usual pattern of autoimmune diseases. Nevertheless, this very rare association does not appear to be fortuitous. PMID:7071576

  8. IgA Antibodies in Rett Syndrome

    ERIC Educational Resources Information Center

    Reichelt, K. L.; Skjeldal, O.

    2006-01-01

    The level of IgA antibodies to gluten and gliadin proteins found in grains and to casein found in milk, as well as the level of IgG to gluten and gliadin, have been examined in 23 girls with Rett syndrome and 53 controls. Highly statistically significant increases were found for the Rett population compared to the controls. The reason for this…

  9. Allergenicity of the pollen of Pistacia.

    PubMed

    Keynan, N; Tamir, R; Waisel, Y; Reshef, A; Spitz, E; Shomer-Ilan, A; Geller-Bernstein, C

    1997-03-01

    Differences in IgE binding and skin responses to pollen extracts of four species of Pistacia, and some immunochemical characteristics of this pollen were investigated. The incidence of positive SPT among atopic patients varied between 31.5% to the pollen extracts of P. vera and 24.6% to P. palaestina. The antigens are located on the exine of the grains as well as in their cytoplasm. Some of the antigens are common to all four species, whereas others seem to be specific. Cross-reactivity was found among the four species of Pistacia and between them and Schinus terebintifolious. Five conspicuous IgE-binding bands were observed in the immunoblots of the four examined species, the bands of 49, 57, 64, 68, and 79 kDa. The 36-37-kDa band of P. lentiscus and the 60- and 84-kDa bands of P. atlantica and P. vera were also noticeable. As the flowering seasons of Pistacia and Schinus do not overlap, the patients are exposed to such pollen for more than 4 months a year. Apparently, Pistacia pollen is a major source of allergy. PMID:9140524

  10. Cholera toxin B suppresses allergic inflammation through induction of secretory IgA.

    PubMed

    Smits, H H; Gloudemans, A K; van Nimwegen, M; Willart, M A; Soullié, T; Muskens, F; de Jong, E C; Boon, L; Pilette, C; Johansen, F-E; Hoogsteden, H C; Hammad, H; Lambrecht, B N

    2009-07-01

    In healthy individuals, humoral immune responses to allergens consist of serum IgA and IgG4, whereas cellular immune responses are controlled by regulatory T (Treg) cells. In search of new compounds that might prevent the onset of allergies by stimulating this type of immune response, we have focused on the mucosal adjuvant, cholera toxin B (CTB), as it induces the formation of Treg cells and production of IgA. Here, we have found that CTB suppresses the potential of dendritic cells to prime for Th2 responses to inhaled allergen. When we administered CTB to the airways of naïve and allergic mice, it strongly suppressed the salient features of asthma, such as airway eosinophilia, Th2 cytokine synthesis, and bronchial hyperreactivity. This beneficial effect was only transferable to other mice by transfer of B but not of T lymphocytes. CTB caused a transforming growth factor-beta-dependent rise in antigen-specific IgA in the airway luminal secretions, which was necessary for its preventive and curative effect, as all effects of CTB were abrogated in mice lacking the luminal IgA transporting polymeric Ig receptor. Not only do these findings show a novel therapeutic avenue for allergy, they also help to explain the complex relationship between IgA levels and risk of developing allergy in humans. PMID:19404246

  11. Low molecular weight IgM in selective IgA deficiency.

    PubMed Central

    Kwitko, A O; Roberts-Thomson, P J; Shearman, D J

    1982-01-01

    Thirty-nine persons with selective IgA deficiency were studied. These comprised 27 subjects found by population screening and 12 by other means. Low molecular weight (LMW) serum IgM was sought in 28 of the 39 persons. Nine of the 28 (32%) had LMW IgM detectable by a sensitive gel filtration technique. Of 17 patients discovered by screening, five (29%) had LMW IgM. In the nine positive persons, LMW IgM constituted up to 17% of the total serum IgM concentration. Eight of the nine IgA deficient persons with LMW IgM, had clinical disease while associated disease in the entire IgA deficient population was less frequent. Serum immune complexes were demonstrated in five of seven subjects with LMW IgM using a C1q-dependent radioimmunoassay; four of these had immune complex associated disorders, three with polyarthritis and one with glomerulonephritis. Because circulating immune complexes are frequently detected in IgA deficient persons without disease, it is proposed that the presence of LMW serum IgM in IgA deficiency may be associated with disease due to the formation of specific pathogenic immune complexes. PMID:7172505

  12. Levels and complexity of IgA antibody against oral bacteria in samples of human colostrum.

    PubMed

    Petrechen, L N; Zago, F H; Sesso, M L T; Bertoldo, B B; Silva, C B; Azevedo, K P; de Lima Pereira, S A; Geraldo-Martins, V R; Ferriani, V P L; Nogueira, R D

    2015-01-01

    Streptococcus mutans (SM) have three main virulence antigens: glucan binding protein B (gbpB), glucosyltransferase (Gtf) and antigens I/II (Ag I/II) envolved in the capacity of those bacteria to adhere and accumulate in the dental biofilm. Also, the glycosyltransferases 153 kDa of Streptococcus gordonii (SGO) and 170kDa of Streptococcus sanguinis (SSA) were important antigens associated with the accumulation of those bacterias. Streptococcus mitis (SMI) present IgA1 protease of 202 kDa. We investigated the specificity and levels IgA against those antigens of virulence in samples of human colostrum. This study involved 77 samples of colostrum that were analyzed for levels of immunoglobulian A, M and G by Elisa. The specificity of IgA against extracts of SM and initials colonizators (SSA, SMI, SGO) were analyzed by the Western blot. The mean concentration of IgA was 2850.2 (±2567.2) mg/100 mL followed by IgM and IgG (respectively 321.8±90.3 and 88.3±51.5), statistically different (p<0.05). Results showed that the majority of samples had detectable levels of IgA antibodies to extracts of bacteria antigens and theirs virulence antigens. To SM, the GbpB was significantly lower detected than others antigens of SM (p<0.05). High complexities of response to Ags were identified in the samples. There were no significant differences in the mean number of IgA-reactive Ags between the antigens (p>0.4). So, the breast milk from first hours after birth presented significant levels of IgA specific against important virulence of antigens those oral streptococci, which can disrupt the installation and accumulation process of these microorganisms in the oral cavity. PMID:25175558

  13. Immunochemical characterization of acacia pollen allergens and evaluation of cross-reactivity pattern with the common allergenic pollens.

    PubMed

    Shamsbiranvand, Mohammad-Hosein; Khodadadi, Ali; Assarehzadegan, Mohammad-Ali; Borsi, Seyed Hamid; Amini, Akram

    2014-01-01

    Pollen from the Acacia has been reported as an important source of pollinosis in tropical and subtropical regions of the world. The aim of this study was to characterize the IgE binding protein of Acacia farnesiana pollen extract and evaluate cross-reactivity with the most allergenic pollens. In this study, pollen extract was fractionated by SDS-PAGE and the allergenic profile was determined by IgE-immunoblotting and specific ELISA using forty-two Acacia allergic patients. Potential cross-reactivity among Acacia and selected allergenic plants was evaluated with ELISA and immunoblotting inhibition experiments. There were several resolved protein fractions on SDS-PAGE which ranged from 12 to 85 kDa. Several allergenic protein bands with molecular weights approximately between 12 and 85 kDa were recognized by IgE-specific antibodies from Acacia allergic patients in the immunoblot assay. The inhibition by the Prosopis juliflora pollen extract was more than those by other pollen extracts. Moreover, the wheal diameters generated by the Acacia pollen extract were highly correlated with those of P. juliflora pollen extracts. The findings suggest that several proteins such as 15, 23, 45, and 50 kDa proteins could be used as diagnostic and therapeutic reagents for patients allergic to A. farnesiana and P. juliflora. PMID:24949020

  14. Immunochemical Characterization of Acacia Pollen Allergens and Evaluation of Cross-Reactivity Pattern with the Common Allergenic Pollens

    PubMed Central

    Shamsbiranvand, Mohammad-Hosein; Khodadadi, Ali; Assarehzadegan, Mohammad-Ali; Borsi, Seyed Hamid; Amini, Akram

    2014-01-01

    Pollen from the Acacia has been reported as an important source of pollinosis in tropical and subtropical regions of the world. The aim of this study was to characterize the IgE binding protein of Acacia farnesiana pollen extract and evaluate cross-reactivity with the most allergenic pollens. In this study, pollen extract was fractionated by SDS-PAGE and the allergenic profile was determined by IgE-immunoblotting and specific ELISA using forty-two Acacia allergic patients. Potential cross-reactivity among Acacia and selected allergenic plants was evaluated with ELISA and immunoblotting inhibition experiments. There were several resolved protein fractions on SDS-PAGE which ranged from 12 to 85 kDa. Several allergenic protein bands with molecular weights approximately between 12 and 85 kDa were recognized by IgE-specific antibodies from Acacia allergic patients in the immunoblot assay. The inhibition by the Prosopis juliflora pollen extract was more than those by other pollen extracts. Moreover, the wheal diameters generated by the Acacia pollen extract were highly correlated with those of P. juliflora pollen extracts. The findings suggest that several proteins such as 15, 23, 45, and 50 kDa proteins could be used as diagnostic and therapeutic reagents for patients allergic to A. farnesiana and P. juliflora. PMID:24949020

  15. Recent advances in the understanding and management of IgA nephropathy

    PubMed Central

    Lai, Kar Neng; Leung, Joseph C.K.; Tang, Sydney C.W.

    2016-01-01

    Since its first description in 1968, IgA nephropathy has remained the most common form of primary glomerulonephritis leading to chronic kidney disease in developed countries. The clinical progression varies, and consequent end-stage renal disease occurs in 30% to 40% of patients 20 to 30 years after the first clinical presentation. Current data implicate overproduction of aberrantly glycosylated IgA1 as being pivotal in the induction of renal injury. Effective and specific treatment is still lacking, and new therapeutic approaches will be developed after better understanding the disease pathogenesis.

  16. Structure and function relationships in IgA.

    PubMed

    Woof, J M; Russell, M W

    2011-11-01

    Immunoglobulin A (IgA) has a critical role in immune defense particularly at the mucosal surfaces, and is equipped to do so by the unique structural attributes of its heavy chain and by its ability to polymerize. Here, we provide an overview of human IgA structure, describing the distinguishing features of the IgA1 and IgA2 subclasses and mapping the sites of interaction with host receptors important for IgA's functional repertoire. Remarkably, these same interaction sites are targeted by binding proteins and proteases produced by various pathogens as a means to subvert the protective IgA response. As interest in the prospect of therapeutic IgA-based monoclonal antibodies grows, the emerging understanding of the relationship between IgA structure and function will be invaluable for maximizing the potential of these novel reagents. PMID:21937984

  17. Analyzing antibody activity in IgA nephropathy

    PubMed Central

    Glassock, Richard J.

    2009-01-01

    IgA nephropathy is a chronic kidney disease defined by deposition of IgA in the glomeruli. An abnormality in the glycosylation of the hinge region of the IgA1 isotype of IgA is fundamental to the origins of this very common form of glomerulonephritis. In this issue of the JCI, Suzuki and coworkers describe the characteristics of IgG autoantibodies to the abnormally glycosylated IgA1 secreted by immortalized B cells derived from patients with sporadic forms of IgA nephropathy (see the related article beginning on page 1668). These IgG autoantibodies displayed remarkably restricted heterogeneity. These observations offer new insights into disease pathogenesis and may lead to new methods of diagnosis, monitoring, and therapy for patients with IgA nephropathy. PMID:19504718

  18. Biological and therapeutic properties of bee pollen: a review.

    PubMed

    Denisow, Bożena; Denisow-Pietrzyk, Marta

    2016-10-01

    Natural products, including bee products, are particularly appreciated by consumers and are used for therapeutic purposes as alternative drugs. However, it is not known whether treatments with bee products are safe and how to minimise the health risks of such products. Among others, bee pollen is a natural honeybee product promoted as a valuable source of nourishing substances and energy. The health-enhancing value of bee pollen is expected due to the wide range of secondary plant metabolites (tocopherol, niacin, thiamine, biotin and folic acid, polyphenols, carotenoid pigments, phytosterols), besides enzymes and co-enzymes, contained in bee pollen. The promising reports on the antioxidant, anti-inflammatory, anticariogenic antibacterial, antifungicidal, hepatoprotective, anti-atherosclerotic, immune enhancing potential require long-term and large cohort clinical studies. The main difficulty in the application of bee pollen in modern phytomedicine is related to the wide species-specific variation in its composition. Therefore, the variations may differently contribute to bee-pollen properties and biological activity and thus in therapeutic effects. In principle, we can unequivocally recommend bee pollen as a valuable dietary supplement. Although the bee-pollen components have potential bioactive and therapeutic properties, extensive research is required before bee pollen can be used in therapy. © 2016 Society of Chemical Industry. PMID:27013064

  19. Role of IgA receptors in the pathogenesis of IgA nephropathy.

    PubMed

    Lechner, Sebastian M; Papista, Christina; Chemouny, Jonathan M; Berthelot, Laureline; Monteiro, Renato C

    2016-02-01

    Immunoglobulin A nephropathy (IgAN) or Berger's disease is the most common form of primary glomerulonephritis in the world and one of the first causes of end-stage renal failure. IgAN is characterized by the accumulation of immune complexes containing polymeric IgA1 in mesangial areas. The pathogenesis of this disease involves the deposition of polymeric and hypogalactosylated IgA1 (Gd-IgA1) in the mesangium. Quantitative and structural changes of Gd-IgA1 play a key role in the development of the disease due to functional abnormalities of two IgA receptors: the FcαRI (CD89) expressed by blood myeloid cells and the transferrin receptor (CD71) on mesangial cells. Abnormal Gd-IgA1 induces release of soluble CD89, which participates in the formation of circulating IgA1 complexes. These complexes are trapped by CD71 that is overexpressed on mesangial cells in IgAN patients together with the crosslinking enzyme transglutaminase 2 allowing pathogenic IgA complex formation in situ and mesangial cell activation. A humanized mouse model expressing IgA1 and CD89 develops IgAN in a similar manner as patients. In this model, a food antigen, the gliadin, was shown to be crucial for circulating IgA1 complex formation and deposition, which could be prevented by a gluten-free diet. Identification of these new partners opens new therapeutic prospects for IgAN treatment. PMID:26572664

  20. Regulation of IgA responses in cattle, humans and mice.

    PubMed

    Estes, D Mark

    2010-12-15

    Secretory IgA (SIgA) constitutes the largest component of the humoral immune system of the body with gram quantities of this isotype produced by mammals on a daily basis. Secretory IgA (SIgA) antibodies function by both blocking pathogen/commensal entry at mucosal surfaces and virus neutralization. Several pathways of induction of IgA responses have been described which depend on T cells (T cell dependent or TD) pathways or are independent of T cells (T-independent or TI) and are mediated by dendritic cells (DCs) and/or epithelial cells. Many elements of IgA regulation readily cross species barriers (adjuvants, soluble and cognate factors) and are highly conserved whereas other pathways may be more specific to any given species and must be evaluated. Regulation of IgA production in cattle is not completely understood and thus we have focused in part on highly conserved factors such as transforming growth factor beta, Type I and Type 2 interferons, neuropeptides which interdigitate mucosal tissues (vasoactive intestinal peptide or VIP), and a small peptide (IgA inducing peptide or IGIP) which can serve as targets for modulation and increasing SIgA virus-specific antibodies. We have evaluated the potential utility of modulating these factors in vitro in regulation of qualitative aspects of antibodies of the IgM, IgG and IgA isotypes at mucosal surfaces and in secretions of the upper and lower respiratory tract to a virus of economic and public health importance, foot and mouth disease virus (FMDV). IgA responses in cattle are essential for host defense in response to various infectious agents. In cattle, IgA is not released into the colostrum, as is the case for other mammals but only IgG1 is selectively transported. In previous studies in cattle, IgA has been shown to be regulated by several cytokines including IFN-gamma, Type I interferons such as IFN-alpha and IFN-tau, transforming growth factor beta, IgA inducing peptide and other potential factors such as APRIL

  1. Determination of allergenic load and pollen count of Cupressus arizonica pollen by flow cytometry using Cup a1 polyclonal antibody.

    PubMed

    Benítez, Francisco Moreno; Camacho, Antonio Letrán; Del Cuvillo Bernal, Alfonso; de Medina, Pedro Lobatón Sánchez; Cózar, Francisco J García; Romeu, Ma Luisa Espinazo

    2013-07-10

    Background: There is an increase in the incidence of pollen related allergy, thus information on pollen schedules would be a great asset for physicians to improve the clinical care of patients. Like cypress pollen sensitization shows a high prevalence among the causes of allergic rhinitis, and therefore it is of interest to use it like a model of study, distinguishing cypress pollen, pollen count and allergenic load level. In this work, we use a flow cytometry based technique to obtain both Cupressus arizonica pollen count and allergenic load, using specific rabbit polyclonal antibody Cup a1 and its comparison with optical microscopy technique measurement. Methods: Airborne samples were collected from Burkard Spore-Trap and Burkard Cyclone Cupressus arizonica pollen was studied using specific rabbit polyclonal antibody Cup a1, labelled with AlexaFluor(®) 488 or 750 and analysed by Flow Cytometry in both an EPICS XL and Cyan ADP cytometers (Beckman Coulter(®) ). Optical microscopy study was realized with a Leica optical microscope. Bland & Altman was used to determine agreement between both techniques measured. Results: We can identify three different populations based on rabbit polyclonal antibody Cup a1 staining. The main region (44.5%) had 97.3% recognition, a second region (25%) with 28% and a third region (30.5%) with 68% respectively. Immunofluorescence and confocal microscopy showed that main region corresponds to whole pollen grains, the second region are pollen without exine and the third region is constituted by smaller particles with allergenic properties. Pollen schedule shows a higher correlation measured by optical microscopy and flow cytometry in the pollen count with a p-value: 0.0008E(-2) and 0.0002 with regard to smaller particles, so the Bland & Altman measurement showed a good correlation between them, p-value: 0,0003. Conclusion: Determination of pollen count and allergenic load by flow cytometry represents an important tool in the

  2. Serum IgA levels induced by rotavirus natural infection, but not following immunization with the RRV-TV vaccine (Rotashield), correlate with protection.

    PubMed

    González, Rosabel; Franco, Manuel; Sarmiento, Luis; Romero, Milagros; Schael, Irene Pérez

    2005-08-01

    To directly compare serum rotavirus specific IgA as a marker of protection in children vaccinated with the RRV-TV (Rotashield) vaccine and in naturally infected children, we studied pre-existing rotavirus IgA antibodies by ELISA assays in these groups of children within the first 5 days after the onset of a diarrhea episode, due or not to rotavirus. In immunized children, rotavirus IgA titers were similar between infected and non-RV infected children. In non-immunized children, the proportion with rotavirus IgA titers was significantly greater in non-RV infected children (58%) than in infected children (31%). Additionally, a titer >/=1:800 was associated with 68% protection. Thus, in this study serum rotavirus IgA showed a good correlation with protection in children pre-exposed to natural infection but not in those immunized with the RRV-TV vaccine. PMID:15977224

  3. Pollen spectrum and risk of pollen allergy in central Spain.

    PubMed

    Perez-Badia, Rosa; Rapp, Ana; Morales, Celia; Sardinero, Santiago; Galan, Carmen; Garcia-Mozo, Herminia

    2010-01-01

    The present work analyses the airborne pollen dynamic of the atmosphere of Toledo (central Spain), a World Heritage Site and an important tourist city receiving over 2 millions of visitors every year. The airborne pollen spectrum, the annual dynamics of the most important taxa, the influence of meteorological variables and the risk of suffering pollen allergy are analysed. Results of the present work are compared to those obtained by similar studies in nearby regions. The average annual Pollen Index is 44,632 grains, where 70-90 percent is recorded during February-May. The pollen calendar includes 29 pollen types, in order of importance; Cupressaceae (23.3 percent of the total amount of pollen grains), Quercus (21.2 percent), and Poaceae and Olea (11.5 and 11.2 percent, respectively), are the main pollen producer taxa. From an allergological viewpoint, Toledo is a high-risk locality for the residents and tourist who visit the area, with a great number of days exceeding the allergy thresholds proposed by the Spanish Aerobiological Network (REA). The types triggering most allergic processes in Toledo citizens and tourists are Cupressaceae, Platanus, Olea, Poaceae, Urticaceae and Chenopodiaceae-Amaranthaceae. Allergic risk increases in 3 main periods: winter (January-March), with the main presence of the Cupressaceae type; spring, characterized by Poaceae, Olea, Platanus and Urticaceae pollen types; and, finally, late summer (August-September), characterized by Chenopodiaceae- Amaranthaceae pollen type, which are the main cause of allergies during these months. PMID:20684492

  4. Development of recombinant human IgA for anticardiolipin antibodies assay standardization.

    PubMed

    Knappik, Achim; Capuano, Francesco; Frisch, Christian; Ylera, Francisco; Bonelli, Fabrizio

    2009-09-01

    Controls and calibrators in autoimmune assays are typically developed from patient sera. However, the use of sera is accompanied by a number of disadvantages, such as lack of monospecificity, lack of assay comparability, and supply limitations. Ideally, the control reagent would be an antigen-specific human monoclonal antibody preparation that is defined and pure, easy to produce without any supply limitations, and of defined isotype (IgG, IgM, or IgA). The generation of antigen-specific human monoclonal antibodies has been complicated, but recent advances in development of fully human antibodies by means of in vitro antibody gene library selection has opened a way for the isolation of human antibodies to virtually any antigen, including self-antigens. Such antibodies can be converted to any isotype by gene cloning. Here we developed a set of human monoclonal IgA antibodies specific for the cardiolipin-beta2-glycoprotein 1 complex, using the HuCAL technology. We evaluated the IgA variants of those antibodies for their use as standards in IgA anticardiolipin antibody assays and compared these reagents with serum controls. Such recombinant antibodies may ultimately replace patient sera as assay control and calibration reagents. PMID:19758150

  5. Corticosteroid therapy in IgA nephropathy.

    PubMed

    Lv, Jicheng; Xu, Damin; Perkovic, Vlado; Ma, Xinxin; Johnson, David W; Woodward, Mark; Levin, Adeera; Zhang, Hong; Wang, Haiyan

    2012-06-01

    The benefits and risks of steroids for the treatment of IgA nephropathy remain uncertain. We systematically searched MEDLINE, EMBASE, and the Cochrane Library for randomized, controlled trials of corticosteroid therapy for IgA nephropathy published between 1966 and March 2011. We identified nine relevant trials that included 536 patients who had urinary protein excretion >1 g/d and normal renal function. Forty-six (8.6%) of these patients developed a kidney failure event, defined as doubling of the serum creatinine/halving of the GFR or ESRD. Overall, steroid therapy was associated with a lower risk for kidney failure (relative risk, 0.32 [95% confidence interval [CI], 0.15-0.67]; P=0.002) and a reduction in proteinuria (weighted mean difference, -0.46 g/d [95% CI, -0.63 to -0.29 g/d]), with no evidence of heterogeneity in these outcomes. Subgroup analysis suggested that the dose modifies the effect of steroids for renal protection (P for heterogeneity=0.030): Relatively high-dose and short-term therapy (prednisone >30 mg/d or high-dose pulse intravenous methylprednisolone with duration ≤1 year) produced significant renal protection, whereas low-dose, long-term steroid use did not. Steroid therapy was associated with a 55% higher risk for adverse events. The quality of included studies was low, however, limiting the generalizability of the results. In conclusion, steroids appear to provide renal protection in patients with IgA nephropathy but increase the risk for adverse events. Reliably defining the efficacy and safety of steroids in IgA nephropathy requires a high-quality trial with a large sample size. PMID:22539830

  6. Activation of rat complement by soluble and insoluble rat IgA immune complexes.

    PubMed

    Rits, M; Hiemstra, P S; Bazin, H; Van Es, L A; Vaerman, J P; Daha, M R

    1988-12-01

    The ability of rat monoclonal IgA, specific for 2,4-dinitrophenyl (DNA), to activate the complement (C) system of the rat was investigated using aggregated IgA or IgA immune complexes (IC). IgA was coated onto a solid phase, and tested for its capacity to bind C3 upon incubation at 37 degrees C in normal rat serum (NRS) in the presence of Mg-EGTA. Binding of C3 was observed dependent on the dose of dimeric (d-), polymeric (p-) and secretory IgA tested. In contrast, little C3 fixation was observed in this system with monomeric (m-) rat IgA or with mouse m- and d-IgA (MOPC315). Soluble and insoluble rat IgA IC were prepared using dinitrophenylated rat serum albumin (DNP8RSA) as antigen (Ag), and assessed for C activation. It was shown that insoluble IC (immune precipitates; IP) containing m-, d- or pIgA of rat origin activate the alternative pathway of rat C, as demonstrated by their capacity to induce C consumption in NRS in the presence of Mg-EGTA. When p- and m-IgA IP were compared for their capacity to activate C, it was found that p-IgA activated C four times as efficiently as m-IgA IP (at 2 mg/ml). Soluble rat IgA IC were prepared in an excess of DNP8RSA, fractionated by gel filtration on Sepharose 6B, and analyzed for C activation and antibody (Ab)/Ag ratio. In contrast to m-IgA IP, soluble m-IgA did not activate C. On the other hand soluble d-IgA IC activated C dependent on their concentration and size: at a concentration of 0.1 mg/ml high-molecular weight d-IgA IC with a high Ab/Ag ratio were four times as efficient as low-molecular weight IC with a low Ab/Ag ratio, and twice as efficient as IP prepared at equivalence. To demonstrate the induction by IgA of the assembly of the terminal membrane attack complex, trinitrophenyl (TNP)-conjugated rat red blood cells (TNP-RRBC) coated with d- or p-IgA were shown to be lysed in NRS in the presence of Mg-EGTA. No lysis of m-IgA-coated TNP-RRBC was observed. The results in this study demonstrate that both soluble and

  7. The Arabidopsis KINβγ Subunit of the SnRK1 Complex Regulates Pollen Hydration on the Stigma by Mediating the Level of Reactive Oxygen Species in Pollen.

    PubMed

    Gao, Xin-Qi; Liu, Chang Zhen; Li, Dan Dan; Zhao, Ting Ting; Li, Fei; Jia, Xiao Na; Zhao, Xin-Ying; Zhang, Xian Sheng

    2016-07-01

    Pollen-stigma interactions are essential for pollen germination. The highly regulated process of pollen germination includes pollen adhesion, hydration, and germination on the stigma. However, the internal signaling of pollen that regulates pollen-stigma interactions is poorly understood. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex which plays important roles in the regulation of plant development. Here, we showed that KINβγ was a cytoplasm- and nucleus-localized protein in the vegetative cells of pollen grains in Arabidopsis. The pollen of the Arabidopsis kinβγ mutant could not germinate on stigma, although it germinated normally in vitro. Further analysis revealed the hydration of kinβγ mutant pollen on the stigma was compromised. However, adding water to the stigma promoted the germination of the mutant pollen in vivo, suggesting that the compromised hydration of the mutant pollen led to its defective germination. In kinβγ mutant pollen, the structure of the mitochondria and peroxisomes was destroyed, and their numbers were significantly reduced compared with those in the wild type. Furthermore, we found that the kinβγ mutant exhibited reduced levels of reactive oxygen species (ROS) in pollen. The addition of H2O2 in vitro partially compensated for the reduced water absorption of the mutant pollen, and reducing ROS levels in pollen by overexpressing Arabidopsis CATALASE 3 resulted in compromised hydration of pollen on the stigma. These results indicate that Arabidopsis KINβγ is critical for the regulation of ROS levels by mediating the biogenesis of mitochondria and peroxisomes in pollen, which is required for pollen-stigma interactions during pollination. PMID:27472382

  8. Novel lectin-independent approach to detect galactose-deficient IgA1 in IgA nephropathy

    PubMed Central

    Yasutake, Junichi; Suzuki, Yusuke; Suzuki, Hitoshi; Hiura, Naoko; Yanagawa, Hiroyuki; Makita, Yuko; Kaneko, Etsuji; Tomino, Yasuhiko

    2015-01-01

    Background Galactose-deficient IgA1 (Gd-IgA1) is a critical effector molecule in the pathogenesis of IgA nephropathy (IgAN). Although many researchers have measured serum levels of Gd-IgA1 using snail helix aspersa agglutinin (HAA) lectin-based assay, the lectin-dependent assay has some serious problems in robustness. In this study, we aimed to establish a more robust and stable enzyme-linked immunosorbent assay (ELISA) method that uses a specific monoclonal antibody to recognize a hinge region in human Gd-IgA1 (Gd-IgA1 ELISA). Methods Rats were immunized with human Gd-IgA1 hinge region peptide to obtain Gd-IgA1-specific monoclonal antibody KM55. Gd-IgA1 ELISA for specifically detecting serum Gd-IgA1 was consequently constructed. Serum Gd-IgA1 concentrations in human subjects were measured using KM55 ELISA assay. To further confirm specificity of the Gd-IgA1-specific antibody, KM55 was also applied for immunofluorescence staining of glomerular Gd-IgA1 in paraffin-embedded sections of renal biopsy specimens. Results Measurement of serum levels of Gd-IgA1 in human subjects by Gd-IgA1 ELISA revealed increased serum Gd-IgA1 level in patients with IgAN compared with patients with other renal diseases or non-renal diseases. Importantly, the results obtained from Gd-IgA1 ELISA positively correlated with those from the HAA lectin-based assay (R = 0.75). Immunofluorescence staining of renal biopsy specimens with KM55 detected glomerular co-localization of Gd-IgA1 and IgA. Conclusion This novel lectin-independent method with KM55 for measuring serum levels of Gd-IgA1 can pave the way for more convincing diagnosis and activity assessment of IgAN, and can expedite clinical research to better understand this difficult disease. PMID:26109484

  9. Pollen Dispersion, Pollen Viability and Pistil Receptivity in Leymus chinensis

    PubMed Central

    HUANG, ZEHAO; ZHU, JINMAO; MU, XIJIN; LIN, JINXING

    2004-01-01

    • Background and Aims Leymus chinensis is an economically and ecologically important grass that is widely distributed across eastern areas of the Eurasian steppe. A major problem facing its propagation by man is its low sexual reproductivity. The causes of low fecundity are uncertain, largely because many aspects of the reproductive biology of this species remained unknown or incomplete. This study aims to address some of these issues. • Methods Pollen dispersion, pollen viability, pollen longevity and pistil receptivity were studied in a representative, natural population of L. chinensis growing in Inner Mongolia. • Key Results Flowering of L. chinensis occurred at the end of June and lasted for 5 d. Pollination peaked between 1600 h and 1700 h, and about 56·1 % of the total pollen grains were released at this time. Pollen density was highest towards the middle of flowering spikes and lowest at the bottom over the 5 d measurement period. Pollen viability (62·4 %) assessed using TTC was more accurate than using IKI (85·6 %); 50 % of pollen arriving on stigmas germinated. Pollen remained viable for only 3 h and the pollen : ovule ratio was 79 333 : 1. Pistil receptivity lasted for only 3 h and, overall, 86·7 % of pistils were pollinated. Within the spike, the relative fecundity of different positions was middle > lower > upper throughout the period of pollination; daily variation of fecundity was similar to that of the pollen flow. The spikes that opened on the day of highest pollen density exhibited the highest fecundity (36·0 %). No seeds were produced by self‐pollination. • Conclusions The data suggest that low pollen viability, short pollen longevity and short pistil receptivity all appear to contribute to the low seed production typical of this important forage crop. PMID:14744707

  10. Explanatory style and Immunoglobulin A (IgA).

    PubMed

    Brennan, F X; Charnetski, C J

    2000-01-01

    The construct of explanatory style has been related to numerous aspects of human psychology, including health. Our research has focused on the effects of various psychological variables on the immune system, in particular Immunoglobulin A (IgA). We had participants fill out the Attributional Style Questionnaire (ASQ), the predominant measure of explanatory style, and assayed saliva samples for secretory IgA. No relationship was observed between overall ASQ score and IgA, or composite optimism score and IgA. However, we observed significant negative correlations between both the composite pessimism score and IgA, as well as the hopelessness score and IgA. Pessimistic explanatory style may therefore be related to immune system deficits and poor health. PMID:11330488

  11. Large Eddy Simulation of Pollen Transport in the Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Chamecki, Marcelo; Meneveau, Charles; Parlange, Marc B.

    2007-11-01

    The development of genetically modified crops and questions about cross-pollination and contamination of natural plant populations enhanced the importance of understanding wind dispersion of airborne pollen. The main objective of this work is to simulate the dispersal of pollen grains in the atmospheric surface layer using large eddy simulation. Pollen concentrations are simulated by an advection-diffusion equation including gravitational settling. Of great importance is the specification of the bottom boundary conditions characterizing the pollen source over the canopy and the deposition process everywhere else. The velocity field is discretized using a pseudospectral approach. However the application of the same discretization scheme to the pollen equation generates unphysical solutions (i.e. negative concentrations). The finite-volume bounded scheme SMART is used for the pollen equation. A conservative interpolation scheme to determine the velocity field on the finite volume surfaces was developed. The implementation is validated against field experiments of point source and area field releases of pollen.

  12. Molecular Ice Nucleation Activity of Birch Pollen

    NASA Astrophysics Data System (ADS)

    Felgitsch, Laura; Bichler, Magdalena; Häusler, Thomas; Weiss, Victor U.; Marchetti-Deschmann, Martina; Allmaier, Günter; Grothe, Hinrich

    2015-04-01

    Heterogeneous ice nucleation plays a major part in ecosystem and climate. Due to the triggering of ice cloud formation it influences the radiation balance of the earth, but also on the ground it can be found to be important in many processes of nature. So far the process of heterogeneous ice nucleation is not fully understood and many questions remain to be answered. Biological ice nucleation is hereby from great interest, because it shows the highest freezing temperatures. Several bacteria and fungi act as ice nuclei. A famous example is Pseudomonas syringae, a bacterium in commercial use (Snomax®), which increases the freezing from homogeneous freezing temperatures of approx. -40° C (for small volumes as in cloud droplets) to temperatures up to -2° C. In 2001 it was found that birch pollen can trigger ice nucleation (Diehl et al. 2001; Diehl et al. 2002). For a long time it was believed that this is due to macroscopic features of the pollen surface. Recent findings of Bernhard Pummer (2012) show a different picture. The ice nuclei are not attached on the pollen surface directly, but on surface material which can be easily washed off. This shows that not only the surface morphology, but also specific molecules or molecular structures are responsible for the ice nucleation activity of birch pollen. With various analytic methods we work on elucidating the structure of these molecules as well as the mechanism with which they trigger ice nucleation. To solve this we use various instrumental analytic techniques like Nuclear Magnetic Resonance spectroscopy (NMR), Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS), and Gas-phase Electrophoretic Mobility Molecular Analysis (GEMMA). Also standard techniques like various chromatographic separation techniques and solvent extraction are in use. We state here that this feature might be due to the aggregation of small molecules, with agglomerates showing a specific surface structure. Our results

  13. Characterization of pollen and bacterial community composition in brood provisions of a small carpenter bee.

    PubMed

    McFrederick, Quinn S; Rehan, Sandra M

    2016-05-01

    Many insects obtain gut microbes from their diet, but how a mother's foraging patterns influence the microbes found in her offspring's food remains an open question. To address this gap, we studied a bee that forages for pollen from multiple species of plants and may therefore acquire diverse bacteria from different plants. We tested the hypothesis that pollen diversity correlates with bacterial diversity by simultaneously characterizing these two communities in bee brood provisions for the first time. We used deep sequencing of the plant RBCL gene and the bacterial 16S rRNA gene to characterize pollen and bacterial diversity. We then tested for associations between pollen and bacterial species richness and community composition, as well as co-occurrence of specific bacteria and pollen types. We found that both pollen and bacterial communities were extremely diverse, indicating that mother bees visit a wide variety of flowers for pollen and nectar and subsequently bring a diversity of microbes back into their nests. Pollen and bacterial species richness and community composition, however, were not correlated. Certain pollen types significantly co-occurred with the most proportionally abundant bacteria, indicating that the plants these pollen types came from may serve as reservoirs for these bacteria. Even so, the overall diversity of these communities appears to mask these associations at a broader scale. Further study of these pollen and bacteria associations will be important for understanding the complicated relationship between bacteria and wild bees. PMID:26945527

  14. Pollen tube growth and guidance: roles of small, secreted proteins

    PubMed Central

    Chae, Keun; Lord, Elizabeth M.

    2011-01-01

    Background Pollination is a crucial step in angiosperm (flowering plant) reproduction. Highly orchestrated pollen–pistil interactions and signalling events enable plant species to avoid inbreeding and outcrossing as a species-specific barrier. In compatible pollination, pollen tubes carrying two sperm cells grow through the pistil transmitting tract and are precisely guided to the ovules, discharging the sperm cells to the embryo sac for fertilization. Scope In Lilium longiflorum pollination, growing pollen tubes utilize two critical mechanisms, adhesion and chemotropism, for directional growth to the ovules. Among several molecular factors discovered in the past decade, two small, secreted cysteine-rich proteins have been shown to play major roles in pollen tube adhesion and reorientation bioassays: stigma/style cysteine-rich adhesin (SCA, approx. 9·3 kDa) and chemocyanin (approx. 9·8 kDa). SCA, a lipid transfer protein (LTP) secreted from the stylar transmitting tract epidermis, functions in lily pollen tube tip growth as well as in forming the adhesive pectin matrix at the growing pollen tube wall back from the tip. Lily chemocyanin is a plantacyanin family member and acts as a directional cue for reorienting pollen tubes. Recent consecutive studies revealed that Arabidopsis thaliana homologues for SCA and chemocyanin play pivotal roles in tip polarity and directionality of pollen tube growth, respectively. This review outlines the biological roles of various secreted proteins in angiosperm pollination, focusing on plant LTPs and chemocyanin. PMID:21307038

  15. Anti-CD20 IgA can protect mice against lymphoma development: evaluation of the direct impact of IgA and cytotoxic effector recruitment on CD20 target cells

    PubMed Central

    Pascal, Virginie; Laffleur, Brice; Debin, Arnaud; Cuvillier, Armelle; van Egmond, Marjolein; Drocourt, Daniel; Imbertie, Laurent; Pangault, Céline; Tarte, Karin; Tiraby, Gérard; Cogné, Michel

    2012-01-01

    Background While most antibody-based therapies use IgG because of their well-known biological properties, some functional limitations of these antibodies call for the development of derivatives with other therapeutic functions. Although less abundant than IgG in serum, IgA is the most abundantly produced Ig class in humans. Besides the specific targeting of its dimeric form to mucosal areas, IgA was shown to recruit polymorphonuclear neutrophils against certain targets more efficiently than does IgG1. Design and Methods In this study, we investigated the various pathways by which anti-tumor effects can be mediated by anti-CD20 IgA against lymphoma cells. Results We found that polymeric human IgA was significantly more effective than human IgG1 in mediating direct killing or growth inhibition of target cells in the absence of complement. We also demonstrated that this direct killing was able to indirectly induce the classical pathway of the complement cascade although to a lesser extent than direct recruitment of complement by IgG. Recruitment of the alternative complement pathway by specific IgA was also observed. In addition to activating complement for lysis of lymphoma cell lines or primary cells from patients with lymphoma, we showed that monomeric anti-CD20 IgA can effectively protect mice against tumor development in a passive immunization strategy and we demonstrated that this protective effect may be enhanced in mice expressing the human FcαRI receptor on their neutrophils. Conclusions We show that anti-CD20 IgA antibodies have original therapeutic properties against lymphoma cells, with strong direct effects, ability to recruit neutrophils for cell cytotoxicity and even recruitment of complement, although largely through an indirect way. PMID:22689689

  16. Intracellular auxin transport in pollen

    PubMed Central

    Dal Bosco, Cristina; Dovzhenko, Alexander; Palme, Klaus

    2012-01-01

    Cellular auxin homeostasis is controlled at many levels that include auxin biosynthesis, auxin metabolism, and auxin transport. In addition to intercellular auxin transport, auxin homeostasis is modulated by auxin flow through the endoplasmic reticulum (ER). PIN5, a member of the auxin efflux facilitators PIN protein family, was the first protein to be characterized as an intracellular auxin transporter. We demonstrated that PIN8, the closest member of the PIN family to PIN5, represents another ER-residing auxin transporter. PIN8 is specifically expressed in the male gametophyte and is located in the ER. By combining genetic, physiological, cellular and biochemical data we demonstrated a role for PIN8 in intracellular auxin homeostasis. Although our investigation shed light on intracellular auxin transport in pollen, the physiological function of PIN8 still remains to be elucidated. Here we discuss our data taking in consideration other recent findings. PMID:22990451

  17. Elevation of Pollen Mitochondrial DNA Copy Number by WHIRLY2: Altered Respiration and Pollen Tube Growth in Arabidopsis.

    PubMed

    Cai, Qiang; Guo, Liang; Shen, Zhao-Rui; Wang, Dan-Yang; Zhang, Quan; Sodmergen

    2015-09-01

    In plants, the copy number of the mitochondrial DNA (mtDNA) can be much lower than the number of mitochondria. The biological significance and regulatory mechanisms of this phenomenon remain poorly understood. Here, using the pollen vegetative cell, we examined the role of the Arabidopsis (Arabidopsis thaliana) mtDNA-binding protein WHIRLY2 (AtWHY2). AtWHY2 decreases during pollen development, in parallel with the rapid degradation of mtDNA; to examine the importance of this decrease, we used the pollen vegetative cell-specific promoter Lat52 to express AtWHY2. The transgenic plants (LWHY2) had very high mtDNA levels in pollen, more than 10 times more than in the wild type (ecotype Columbia-0). LWHY2 plants were fertile, morphologically normal, and set seeds; however, reciprocal crosses with heterozygous plants showed reduced transmission of LWHY2-1 through the male and slower growth of LWHY2-1 pollen tubes. We found that LWHY2-1 pollen had significantly more reactive oxygen species and less ATP compared with the wild type, indicating an effect on mitochondrial respiration. These findings reveal that AtWHY2 affects mtDNA copy number in pollen and suggest that low mtDNA copy numbers might be the normal means by which plant cells maintain mitochondrial genetic information. PMID:26195569

  18. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks.

    PubMed

    Emer, Carine; Vaughan, Ian P; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  19. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks

    PubMed Central

    Emer, Carine; Vaughan, Ian P.; Hiscock, Simon; Memmott, Jane

    2015-01-01

    Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae) affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet) and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam) and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward. PMID:26633170

  20. Floral traits mediate the vulnerability of aloes to pollen theft and inefficient pollination by bees

    PubMed Central

    Hargreaves, Anna L.; Harder, Lawrence D.; Johnson, Steven D.

    2012-01-01

    Background and Aims Pollen-collecting bees are among the most important pollinators globally, but are also the most common pollen thieves and can significantly reduce plant reproduction. The pollination efficiency of pollen collectors depends on the frequency of their visits to female(-phase) flowers, contact with stigmas and deposition of pollen of sufficient quantity and quality to fertilize ovules. Here we investigate the relative importance of these components, and the hypothesis that floral and inflorescence characteristics mediate the pollination role of pollen collection by bees. Methods For ten Aloe species that differ extensively in floral and inflorescence traits, we experimentally excluded potential bird pollinators to quantify the contributions of insect visitors to pollen removal, pollen deposition and seed production. We measured corolla width and depth to determine nectar accessibility, and the phenology of anther dehiscence and stigma receptivity to quantify herkogamy and dichogamy. Further, we compiled all published bird-exclusion studies of aloes, and compared insect pollination success with floral morphology. Key Results Species varied from exclusively insect pollinated, to exclusively bird pollinated but subject to extensive pollen theft by insects. Nectar inaccessibility and strong dichogamy inhibited pollination by pollen-collecting bees by discouraging visits to female-phase (i.e. pollenless) flowers. For species with large inflorescences of pollen-rich flowers, pollen collectors successfully deposited pollen, but of such low quality (probably self-pollen) that they made almost no contribution to seed set. Indeed, considering all published bird-exclusion studies (17 species in total), insect pollination efficiency varied significantly with floral shape. Conclusions Species-specific floral and inflorescence characteristics, especially nectar accessibility and dichogamy, control the efficiency of pollen-collecting bees as pollinators of aloes

  1. On the simulation of allergenic pollen exposition and its atmospheric transport on regional scale

    NASA Astrophysics Data System (ADS)

    Biernath, Christian; Klein, Christian; Hoffmann, Peter; Gayler, Sebastian; Priesack, Eckart

    2013-04-01

    In Germany approximately 30% of the population is vulnerable to pollinosis (hay fever). Exposure to allergenic pollen affects vulnerable persons recurring seasonally, but depending on the individual susceptibility to individual pollen species. To prevent the suffering the patients usually use preventive drugs and rely on the current pollen forecast. However, recently used pollen forecast models mainly consider temperature sums to predict pollen exposition by different plant species. The models often fail to describe the impact of regionally variable environmental conditions on plant growth which depends on the soil characteristics that affect the water and nutrient availability. Furthermore, water and nutrient availability may significantly affect the pollen yield and its allergenic potential. Thus, the improvement of the simulations of the exposition of allergenic pollen by plants and atmospheric pollen loads on the regional scale could improve the preventive medication of vulnerable persons. We propose a new soil-plant-atmosphere model system that allows a dynamic ressource aquisition for the plant biomass growth to account for the allergenic potential of exposed pollen and the subsequent pollen transport in the atmosphere. Therefore, to simulate pollen exposure the land surface model Expert-N (soil-plant-system model) was coupled to the Weather Research and Forecast model (WRF). Expert-N uses site specific physical soil properties to simulate the nutrient and water transport, and the carbon and nitrogen turnover, as well as the interactions between plant and soil. The allergenic potential of pollen yield is simulated using a new C- and N-allocation model which accounts for the production of carbon-based secondary compounds (CBSCs). These CBSCs are involved in the determination of the allergenic potential of pollen. The WRF model is used to predict the weather conditions for plant growth. Depending on the weather conditions pollen exposed by the plants is then

  2. A Multiscale Vibrational Spectroscopic Approach for Identification and Biochemical Characterization of Pollen

    PubMed Central

    Bağcıoğlu, Murat; Zimmermann, Boris; Kohler, Achim

    2015-01-01

    Background Analysis of pollen grains reveals valuable information on biology, ecology, forensics, climate change, insect migration, food sources and aeroallergens. Vibrational (infrared and Raman) spectroscopies offer chemical characterization of pollen via identifiable spectral features without any sample pretreatment. We have compared the level of chemical information that can be obtained by different multiscale vibrational spectroscopic techniques. Methodology Pollen from 15 different species of Pinales (conifers) were measured by seven infrared and Raman methodologies. In order to obtain infrared spectra, both reflectance and transmission measurements were performed on ground and intact pollen grains (bulk measurements), in addition, infrared spectra were obtained by microspectroscopy of multigrain and single pollen grain measurements. For Raman microspectroscopy measurements, spectra were obtained from the same pollen grains by focusing two different substructures of pollen grain. The spectral data from the seven methodologies were integrated into one data model by the Consensus Principal Component Analysis, in order to obtain the relations between the molecular signatures traced by different techniques. Results The vibrational spectroscopy enabled biochemical characterization of pollen and detection of phylogenetic variation. The spectral differences were clearly connected to specific chemical constituents, such as lipids, carbohydrates, carotenoids and sporopollenins. The extensive differences between pollen of Cedrus and the rest of Pinaceae family were unambiguously connected with molecular composition of sporopollenins in pollen grain wall, while pollen of Picea has apparently higher concentration of carotenoids than the rest of the family. It is shown that vibrational methodologies have great potential for systematic collection of data on ecosystems and that the obtained phylogenetic variation can be well explained by the biochemical composition of

  3. Enzyme-linked immunosorbent assay for detection of serum or mucosal isotype specific IgG and IgA whole virus antibody to influenza A virus in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enzyme-linked immunosorbent assays (ELISA) can be used to detect isotype specific anti-influenza antibodies in biological samples to characterize the porcine immune response to influenza A virus. The isotype antibody assay is based on an indirect ELISA using whole influenza virus as antigen and dete...

  4. Abnormalities of the IgA immune system in members of unrelated pedigrees from patients with IgA nephropathy.

    PubMed Central

    Schena, F P; Scivittaro, V; Ranieri, E; Sinico, R; Benuzzi, S; Di Cillo, M; Aventaggiato, L

    1993-01-01

    In the last few years many investigators have reported the recurrence of primary IgA nephropathy (IgAN) or the presence of persistent microhaematuria and/or proteinuria in family members of patients with IgAN. Our study was undertaken to investigate the relevance of abnormalities in the regulation of the IgA and IgM immune system in microhaematuric and asymptomatic family members of IgAN patients. Fifty-four out of 120 members of nine unrelated pedigrees were examined by urinalysis; polymeric IgA (pIgA), IgA rheumatoid factor (IgARF), IgA1-IgG immune complexes (IgA 1-IgG IC) and IgA 1-IgM IC, and other immunoglobulins were measured in serum samples. Moreover, we studied the production of immunoglobulins, pIgA and IgARF by peripheral blood mononuclear cells (PBMC) in basal conditions and after pokeweed mitogen (PWM) stimulation. Our data demonstrate that persistent microhaematuria was present in 24% of relatives. High serum levels of IgA, mainly pIgA and IgARF, IgA 1-IgG IC and IgA 1-IgM IC occurred in 66% of relatives. Abnormal spontaneous production of IgA by PBMC and after PWM stimulation was present in 64% of family members. Interestingly, high serum levels of IgM and abnormal production of this immunoglobulin by PBMC were observed in relatives. However, the immunological abnormalities did not correlate in any way with the presence of urinary abnormalities such as microhaematuria, which was most likely determined by an underlying glomerular alteration. PMID:8467558

  5. Salivary IgA antibody to glucosyltransferase in man.

    PubMed Central

    Smith, D J; Taubman, M A; Ebersole, J L

    1985-01-01

    Parotid salivas of 97 young adults were screened for IgA antibody to glucosyltransferase (GTF) from laboratory strains of Streptococcus mutans (serotypes c and g). Antibody levels to GTF from serotype c positively correlated with levels to serotype g GTF among these salivas. GTF's were prepared from S. mutans obtained from a subset of individuals in this population. All but one saliva showed IgA antibody activity to all of the GTF tested. In addition, the relative magnitude of each subject's antibody level was generally the highest to the GTF from their own S. mutans. Fractions, enriched for IgA by ammonium sulphate precipitation and gel filtration, showed patterns of functional inhibition of GTF activity which were consistent with patterns of IgA antibody activity in ELISA of unfractionated salivas. These data indicate that detectable levels of IgA antibody to S. mutans GTF exist in many young adult salivas, while this IgA antibody activity reacts with GTF from different biotypes, subjects generally show the highest secretory IgA antibody levels to their own GTF, and the relative amount of IgA antibody to GTF and the ability to inhibit GTF activity are roughly correlated. PMID:2931224

  6. Grass pollen hypersensitivity in mice

    PubMed Central

    McCaskill, A. C.; Hosking, C. S.; Hill, D. J.

    1982-01-01

    Mice were sensitized by intranasal administration of ryegrass pollen. Subsequent nasal challenge with pollen extract led to a `shock' response peaking in severity 4 hr after challenge. Histological examination of lungs revealed the development of a pneumonitis which was most severe 3 days after challenge. ImagesFigure 2 PMID:7106842

  7. A Case of Occupational Rhinitis Induced by Maize Pollen Exposure in a Farmer: Detection of IgE-Binding Components

    PubMed Central

    Sung, Se-Yong; Lee, Won-Yeon; Yong, Suk Joong; Shin, Kye Chul; Park, Hae-Sim; Kim, Hyun-Mi

    2012-01-01

    Corn is a major staple food, along with rice and wheat, in many parts of the world. There are several reports of hypersensitivity to maize pollen. However, cases of occupational allergic rhinitis induced by inhalation of maize pollen are very rare. We herein report the case of a 67-year-old male with occupational rhinitis caused by occupational exposure to maize pollen in a cornfield. He showed positive responses to maize pollen, as well as grass pollens, in skin prick tests. A high level of serum immunoglobulin E (IgE) specific to maize pollen extracts was detected by an enzyme-linked immunosorbent assay (ELISA). Laboratory tests showed a high serum level of total IgE (724 kU/L) and a high level of IgE specific to maize pollen (8.32 kU/L) using the Immuno-CAP system. Occupational rhinitis was confirmed by a nasal provocation test with maize pollen extracts. IgE ELISA inhibition tests showed antibody cross-reactivity between maize pollen and grass pollen extracts. IgE immunoblotting using maize pollen extracts demonstrated a 27 kDa IgE-binding component. These findings suggest that maize pollen can induce IgE-mediated occupational rhinitis in exposed workers. PMID:22211171

  8. Transient Glyco-Engineering to Produce Recombinant IgA1 with Defined N- and O-Glycans in Plants

    PubMed Central

    Dicker, Martina; Tschofen, Marc; Maresch, Daniel; König, Julia; Juarez, Paloma; Orzaez, Diego; Altmann, Friedrich; Steinkellner, Herta; Strasser, Richard

    2016-01-01

    The production of therapeutic antibodies to combat pathogens and treat diseases, such as cancer is of great interest for the biotechnology industry. The recent development of plant-based expression systems has demonstrated that plants are well-suited for the production of recombinant monoclonal antibodies with defined glycosylation. Compared to immunoglobulin G (IgG), less effort has been undertaken to express immunoglobulin A (IgA), which is the most prevalent antibody class at mucosal sites and a promising candidate for novel recombinant biopharmaceuticals with enhanced anti-tumor activity. Here, we transiently expressed recombinant human IgA1 against the VP8* rotavirus antigen in glyco-engineered ΔXT/FT Nicotiana benthamiana plants. Mass spectrometric analysis of IgA1 glycopeptides revealed the presence of complex biantennary N-glycans with terminal N-acetylglucosamine present on the N-glycosylation site of the CH2 domain in the IgA1 alpha chain. Analysis of the peptide carrying nine potential O-glycosylation sites in the IgA1 alpha chain hinge region showed the presence of plant-specific modifications including hydroxyproline formation and the attachment of pentoses. By co-expression of enzymes required for initiation and elongation of human O-glycosylation it was possible to generate disialylated mucin-type core 1 O-glycans on plant-produced IgA1. Our data demonstrate that ΔXT/FT N. benthamiana plants can be engineered toward the production of recombinant IgA1 with defined human-type N- and O-linked glycans. PMID:26858738

  9. PECTIN METHYLESTERASE48 Is Involved in Arabidopsis Pollen Grain Germination1[OPEN

    PubMed Central

    Leroux, Christelle; Bouton, Sophie; Kiefer-Meyer, Marie-Christine; Fabrice, Tohnyui Ndinyanka; Mareck, Alain; Guénin, Stéphanie; Fournet, Françoise; Ringli, Christoph; Pelloux, Jérôme; Driouich, Azeddine; Lerouge, Patrice; Lehner, Arnaud; Mollet, Jean-Claude

    2015-01-01

    Germination of pollen grains is a crucial step in plant reproduction. However, the molecular mechanisms involved remain unclear. We investigated the role of PECTIN METHYLESTERASE48 (PME48), an enzyme implicated in the remodeling of pectins in Arabidopsis (Arabidopsis thaliana) pollen. A combination of functional genomics, gene expression, in vivo and in vitro pollen germination, immunolabeling, and biochemical analyses was used on wild-type and Atpme48 mutant plants. We showed that AtPME48 is specifically expressed in the male gametophyte and is the second most expressed PME in dry and imbibed pollen grains. Pollen grains from homozygous mutant lines displayed a significant delay in imbibition and germination in vitro and in vivo. Moreover, numerous pollen grains showed two tips emerging instead of one in the wild type. Immunolabeling and Fourier transform infrared analyses showed that the degree of methylesterification of the homogalacturonan was higher in pme48−/− pollen grains. In contrast, the PME activity was lower in pme48−/−, partly due to a reduction of PME48 activity revealed by zymogram. Interestingly, the wild-type phenotype was restored in pme48−/− with the optimum germination medium supplemented with 2.5 mm calcium chloride, suggesting that in the wild-type pollen, the weakly methylesterified homogalacturonan is a source of Ca2+ necessary for pollen germination. Although pollen-specific PMEs are traditionally associated with pollen tube elongation, this study provides strong evidence that PME48 impacts the mechanical properties of the intine wall during maturation of the pollen grain, which, in turn, influences pollen grain germination. PMID:25524442

  10. Exposures influencing total IgA level in colostrum.

    PubMed

    Munblit, D; Sheth, S; Abrol, P; Treneva, M; Peroni, D G; Chow, L-Y; Boner, A L; Pampura, A; Warner, J O; Boyle, R J

    2016-02-01

    Immunoglobulin A (IgA) is a predominant immunoglobulin present in human breast milk and is known to play an important role in infant gut immunity maturation. Breast milk composition varies between populations, but the environmental and maternal factors responsible for these variations are still unclear. We examined the relationship between different exposures and levels of IgA in colostrum. The objective of this study was to examine whether exposures analysed influence levels of IgA in colostrum. The present study used 294 colostrum samples from the MecMilk International cohort, collected from women residing in London, Moscow and Verona. Samples were analysed in automated Abbott Architect Analyser. We found an inverse correlation between time postpartum and colostrum total IgA level (r=-0.49, P<0.001). Adjusting for maternal parity, smoking, fresh fruit and fish consumption and allergen sensitization, multiple regression model showed that IgA levels were influenced by colostrum collection time (P<0.0001) and country of collection (P<0.01). Mode of delivery influence did not appear to be significant in univariate comparisons, once adjusted for the above maternal characteristics it showed a significant influence on total IgA (P=0.01). We conclude that the concentration of IgA in colostrum drops rapidly after birth and future studies should always consider this factor in analysis. IgA concentration varied significantly between countries, with the highest level detected in Moscow and lowest in Verona. Mode of delivery effect should be confirmed on larger cohorts. Further work is needed to determine ways to correct for IgA decline over time in colostrum, and to find the cause of variations in IgA levels between the countries. PMID:26387688

  11. Binding and transepithelial transport of immunoglobulins by intestinal M cells: demonstration using monoclonal IgA antibodies against enteric viral proteins.

    PubMed

    Weltzin, R; Lucia-Jandris, P; Michetti, P; Fields, B N; Kraehenbuhl, J P; Neutra, M R

    1989-05-01

    M cells of intestinal epithelia overlying lymphoid follicles endocytose luminal macromolecules and microorganisms and deliver them to underlying lymphoid tissue. The effect of luminal secretory IgA antibodies on adherence and transepithelial transport of antigens and microorganisms by M cells is unknown. We have studied the interaction of monoclonal IgA antibodies directed against specific enteric viruses, or the hapten trinitrophenyl (TNP), with M cells. To produce monospecific IgA antibodies against mouse mammary tumor virus (MMTV) and reovirus type 1, Peyer's patch cells from mucosally immunized mice were fused with myeloma cells, generating hybridomas that secreted virus-specific IgA antibodies in monomeric and polymeric forms. One of two anti-MMTV IgA antibodies specifically bound the viral surface glycoprotein gp52, and 3 of 10 antireovirus IgA antibodies immunoprecipitated sigma 3 and mu lc surface proteins. 35S-labeled IgA antibodies injected intravenously into rats were recovered in bile as higher molecular weight species, suggesting that secretory component had been added on passage through the liver. Radiolabeled or colloidal gold-conjugated mouse IgA was injected into mouse, rat, and rabbit intestinal loops containing Peyer's patches. Light microscopic autoradiography and EM showed that all IgA antibodies (antivirus or anti-TNP) bound to M cell luminal membranes and were transported in vesicles across M cells. IgA-gold binding was inhibited by excess unlabeled IgA, indicating that binding was specific. IgG-gold also adhered to M cells and excess unlabeled IgG inhibited IgA-gold binding; thus binding was not isotype-specific. Immune complexes consisting of monoclonal anti-TNP IgA and TNP-ferritin adhered selectively to M cell membranes, while TNP-ferritin alone did not. These results suggest that selective adherence of luminal antibody to M cells may facilitate delivery of virus-antibody complexes to mucosal lymphoid tissue, enhancing subsequent

  12. Detection of airborne allergen (Pla a 1) in relation to Platanus pollen in Córdoba, South Spain.

    PubMed

    Alcázar, Purificación; Galán, Carmen; Torres, Carmen; Domínguez-Vilches, Eugenio

    2015-01-01

    Córdoba is one of the Spanish cities with the highest records of plane tree pollen grains in the air. Clinical studies have identified Platanus as a major cause of pollinosis. This fact provokes an important public health problem during early spring when these trees bloom. The objective of the study is to evaluate the correlation between airborne pollen counts and Pla a 1 aeroallergen concentrations in Córdoba, to elucidate if airborne pollen can be an accurate measure that helps to explain the prevalence of allergenic symptoms. Pollen sampling was performed during 2011-2012 using a Hirst-type sampler. Daily average concentration of pollen grains (pollen grains/m 3 ) was obtained following the methodology proposed by the Spanish Aerobiology Network. A multi-vial cyclone was used for the aeroallergen quantification. Allergenic particles were measured by ELISA using specific antibodies Pla a 1. The trend of Platanus pollen was characterized by a marked seasonality, reaching high concentrations in a short period of time. Airborne pollen and aeroallergen follow similar trends. The overlapping profile between both variables during both years shows that pollen and Pla a 1 are significantly correlated. The highest significant correlation coefficients were obtained during 2011 and for the post peak. Although some studies have found notable divergence between pollen and allergen concentrations in the air, in the case of Platanus in Córdoba, similar aerobiological dynamics between pollen and Pla a 1 have been found. Allergenic activity was found only during the plane tree pollen season, showing a close relationship with daily pollen concentrations. The obtained pollen potency was similar for both years of study. The results suggest that the allergenic response in sensitive patients to plane tree pollen coincide with the presence and magnitude of airborne pollen. PMID:25780836

  13. CHARACTERIZATION OF THE MAIZE POLLEN TRANSCRIPTOME

    EPA Science Inventory

    Pollen is a primary vehicle for transgene flow from engineered plants to their non-transgenic, native or weedy relatives. Hence, gene flow will be affected by pollen fitness (e.g., how well a particular pollen grain can outcompete other pollen present on the stigma and complete ...

  14. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  15. Identifying urban sources as cause of elevated grass pollen concentrations using GIS and remote sensing

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Ørby, P. V.; Becker, T.; Geels, C.; Schlünssen, V.; Sigsgaard, T.; Bønløkke, J. H.; Sommer, J.; Søgaard, P.; Hertel, O.

    2013-01-01

    We examine here the hypothesis that during flowering, the grass pollen concentrations at a specific site reflect the distribution of grass pollen sources within a few kilometres of this site. We perform this analysis on data from a measurement campaign in the city of Aarhus (Denmark) using three pollen traps and by comparing these observations with a novel inventory of grass pollen sources. The source inventory is based on a new methodology developed for urban-scale grass pollen sources. The new methodology is believed to be generally applicable for the European area, as it relies on commonly available remote sensing data combined with management information for local grass areas. The inventory has identified a number of grass pollen source areas present within the city domain. The comparison of the measured pollen concentrations with the inventory shows that the atmospheric concentrations of grass pollen in the urban zone reflect the source areas identified in the inventory, and that the pollen sources that are found to affect the pollen levels are located near or within the city domain. The results also show that during days with peak levels of pollen concentrations there is no correlation between the three urban traps and an operational trap located just 60 km away. This finding suggests that during intense flowering, the grass pollen concentration mirrors the local source distribution and is thus a local-scale phenomenon. Model simulations aimed at assessing population exposure to pollen levels are therefore recommended to take into account both local sources and local atmospheric transport, and not to rely only on describing regional to long-range transport of pollen. The derived pollen source inventory can be entered into local-scale atmospheric transport models in combination with other components that simulate pollen release in order to calculate urban-scale variations in the grass pollen load. The gridded inventory with a resolution of 14 m is therefore

  16. Identifying urban sources as cause to elevated grass pollen concentrations using GIS and remote sensing

    NASA Astrophysics Data System (ADS)

    Skjøth, C. A.; Ørby, P. V.; Becker, T.; Geels, C.; Schlünssen, V.; Sigsgaard, T.; Bønløkke, J. H.; Sommer, J.; Søgaard, P.; Hertel, O.

    2012-10-01

    We examine here the hypothesis that during flowering, the grass pollen concentrations at a specific site reflect the distribution of grass pollen sources within a few kilometres from this site. We perform this analysis on data from a measurement campaign in the city of Aarhus (Denmark) using three pollen traps and by comparing these observations with a novel inventory of grass pollen sources. The source inventory is based on a new methodology developed for urban scale grass pollen sources. The new methodology is believed to be generally applicable for the European area, as it relies on commonly available remote sensing data combined with management information for local grass areas. The inventory has identified a number of grass pollen source areas present within the city domain. The comparison of the measured pollen concentrations with the inventory shows that the atmospheric concentrations of grass pollen in the urban zone reflects the source areas identified in the inventory, and that these pollen sources that are found to affect the pollen levels are located near and within the city domain. The results also show that during days with peak levels of pollen concentrations, there is no correlation between the three urban traps and an operational trap located just 60 km away. This finding suggests that during intense flowering, the grass pollen concentration mirrors the local source distribution, and is thus a local scale phenomenon. Model simulations aiming at assessment of population exposure to pollen levels are therefore recommended to take into account both local sources and local atmospheric transport, and not rely only on describing regional to long-range transport of pollen. The derived pollen source inventory can be entered into local scale atmospheric transport models in combination with other components that simulates pollen release in order to calculate urban scale variations in the grass pollen load. The gridded inventory with a resolution of 14 m is

  17. Grass pollen allergens globally: the contribution of subtropical grasses to burden of allergic respiratory diseases.

    PubMed

    Davies, J M

    2014-06-01

    Grass pollens of the temperate (Pooideae) subfamily and subtropical subfamilies of grasses are major aeroallergen sources worldwide. The subtropical Chloridoideae (e.g. Cynodon dactylon; Bermuda grass) and Panicoideae (e.g. Paspalum notatum; Bahia grass) species are abundant in parts of Africa, India, Asia, Australia and the Americas, where a large and increasing proportion of the world's population abide. These grasses are phylogenetically and ecologically distinct from temperate grasses. With the advent of global warming, it is conceivable that the geographic distribution of subtropical grasses and the contribution of their pollen to the burden of allergic rhinitis and asthma will increase. This review aims to provide a comprehensive synthesis of the current global knowledge of (i) regional variation in allergic sensitivity to subtropical grass pollens, (ii) molecular allergenic components of subtropical grass pollens and (iii) allergic responses to subtropical grass pollen allergens in relevant populations. Patients from subtropical regions of the world show higher allergic sensitivity to grass pollens of Chloridoideae and Panicoideae grasses, than to temperate grass pollens. The group 1 allergens are amongst the allergen components of subtropical grass pollens, but the group 5 allergens, by which temperate grass pollen extracts are standardized for allergen content, appear to be absent from both subfamilies of subtropical grasses. Whilst there are shared allergenic components and antigenic determinants, there are additional clinically relevant subfamily-specific differences, at T- and B-cell levels, between pollen allergens of subtropical and temperate grasses. Differential immune recognition of subtropical grass pollens is likely to impact upon the efficacy of allergen immunotherapy of patients who are primarily sensitized to subtropical grass pollens. The literature reviewed herein highlights the clinical need to standardize allergen preparations for both

  18. RNA Silencing of Exocyst Genes in the Stigma Impairs the Acceptance of Compatible Pollen in Arabidopsis.

    PubMed

    Safavian, Darya; Zayed, Yara; Indriolo, Emily; Chapman, Laura; Ahmed, Abdalla; Goring, Daphne R

    2015-12-01

    Initial pollen-pistil interactions in the Brassicaceae are regulated by rapid communication between pollen grains and stigmatic papillae and are fundamentally important, as they are the first step toward successful fertilization. The goal of this study was to examine the requirement of exocyst subunits, which function in docking secretory vesicles to sites of polarized secretion, in the context of pollen-pistil interactions. One of the exocyst subunit genes, EXO70A1, was previously identified as an essential factor in the stigma for the acceptance of compatible pollen in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We hypothesized that EXO70A1, along with other exocyst subunits, functions in the Brassicaceae dry stigma to deliver cargo-bearing secretory vesicles to the stigmatic papillar plasma membrane, under the pollen attachment site, for pollen hydration and pollen tube entry. Here, we investigated the functions of exocyst complex genes encoding the remaining seven subunits, SECRETORY3 (SEC3), SEC5, SEC6, SEC8, SEC10, SEC15, and EXO84, in Arabidopsis stigmas following compatible pollinations. Stigma-specific RNA-silencing constructs were used to suppress the expression of each exocyst subunit individually. The early postpollination stages of pollen grain adhesion, pollen hydration, pollen tube penetration, seed set, and overall fertility were analyzed in the transgenic lines to evaluate the requirement of each exocyst subunit. Our findings provide comprehensive evidence that all eight exocyst subunits are necessary in the stigma for the acceptance of compatible pollen. Thus, this work implicates a fully functional exocyst complex as a component of the compatible pollen response pathway to promote pollen acceptance. PMID:26443677

  19. City scale pollen concentration variability

    NASA Astrophysics Data System (ADS)

    van der Molen, Michiel; van Vliet, Arnold; Krol, Maarten

    2016-04-01

    Pollen are emitted in the atmosphere both in the country-side and in cities. Yet the majority of the population is exposed to pollen in cities. Allergic reactions may be induced by short-term exposure to pollen. This raises the question how variable pollen concentration in cities are in temporally and spatially, and how much of the pollen in cities are actually produced in the urban region itself. We built a high resolution (1 × 1 km) pollen dispersion model based on WRF-Chem to study a city's pollen budget and the spatial and temporal variability in concentration. It shows that the concentrations are highly variable, as a result of source distribution, wind direction and boundary layer mixing, as well as the release rate as a function of temperature, turbulence intensity and humidity. Hay Fever Forecasts based on such high resolution emission and physical dispersion modelling surpass traditional hay fever warning methods based on temperature sum methods. The model gives new insights in concentration variability, personal and community level exposure and prevention. The model will be developped into a new forecast tool to serve allergic people to minimize their exposure and reduce nuisance, coast of medication and sick leave. This is an innovative approach in hay fever warning systems.

  20. The role of glycosylation in flavonol-induced pollen germination.

    PubMed

    Taylor, L P; Strenge, D; Miller, K D

    1998-01-01

    Flavonols are small (C15) plant-specific molecules that are required for petunia and maize pollen to germinate. They exist in two chemical forms: the aglycone or glycosyl conjugates. Flavonol-deficient pollen is biochemically complemented by flavonol aglycones but not by the glycosylated forms that accumulate in wild type (WT) pollen. Coincident with the biochemical induction of germination, the added flavonol aglycone is rapidly converted to a galactoside and then to a glucosyl galactoside (diglycoside) that is identical to the compound present in WT pollen. A flavonol 3-O-galactosyltransferase (F3GalTase) activity has been identified that controls the formation of glycosylated flavonols in pollen. Importantly, this enzyme also catalyzes the reverse reaction, i.e. the production of the flavonol aglycone from the galactoside and UDP (Fig. 1). F3GalTase/RevGalTase therefore has the potential to control the level of the bioactive flavonol species and as a result, pollen germination. PMID:9781293

  1. Pollen preference for Psychotria sp. is not learned in the passion flower butterfly, Heliconius erato.

    PubMed

    Salcedo, Christian

    2011-01-01

    Heliconius butterflies are known to maximize fitness by feeding on pollen from Gurania sp. and Psiguria sp. (Cucurbitales: Curcurbitaceae), and Psychotria sp. (Gentianales: Rubiaceae). This specialization involves specific physical, physiological, and behavioral adaptations including efficient search strategies in the forest to locate pollen host plants, pollen removal, and pollen external digestion. Reducing pollen host plant search time is crucial to out-compete other flower visitors and to reduce exposure to predators. One way in which this can be achieved is by using chemical cues to learn from experienced foragers in roosting aggregations. Similar strategies have been documented in bumblebees, where inexperienced individuals learn floral odors from experienced foragers. Behavioral experiments using plants preferred by Heliconius erato suggest that pollen preference in H. erato is an innate trait and consequently learning of chemical cues at roosting aggregations is unlikely. PMID:21529151

  2. The influences of hinge length and composition on the susceptibility of human IgA to cleavage by diverse bacterial IgA1 proteases.

    PubMed

    Senior, Bernard W; Woof, Jenny M

    2005-06-15

    The influences of IgA hinge length and composition on its susceptibility to cleavage by bacterial IgA1 proteases were examined using a panel of IgA hinge mutants. The IgA1 proteases of Streptococcus pneumoniae, Streptococcus sanguis strains SK4 and SK49, Neisseria meningitidis, Neisseria gonorrhoeae, and Haemophilus influenzae cleaved IgA2-IgA1 half hinge, an Ab featuring half of the IgA1 hinge incorporated into the equivalent site in IgA1 protease-resistant IgA2, whereas those of Streptococcus mitis, Streptococcus oralis, and S. sanguis strain SK1 did not. Hinge length reduction by removal of two of the four C-terminal proline residues rendered IgA2-IgA1 half hinge resistant to all streptococcal IgA1 metalloproteinases but it remained sensitive to cleavage by the serine-type IgA1 proteases of Neisseria and Haemophilus spp. The four C-terminal proline residues could be substituted by alanine residues or transferred to the N-terminal extremity of the hinge without affect on the susceptibility of the Ab to cleavage by serine-type IgA1 proteases. However, their removal rendered the Ab resistant to cleavage by all the IgA1 proteases. We conclude that the serine-type IgA1 proteases of Neisseria and Haemophilus require the Fab and Fc regions to be separated by at least ten (or in the case of N. gonorrhoeae type I protease, nine) amino acids between Val(222) and Cys(241) (IgA1 numbering) for efficient access and cleavage. By contrast, the streptococcal IgA1 metalloproteinases require 12 or more appropriate amino acids between the Fab and Fc to maintain a minimum critical distance between the scissile bond and the start of the Fc. PMID:15944283

  3. A Taxonomic Reduced-Space Pollen Model for Paleoclimate Reconstruction

    NASA Astrophysics Data System (ADS)

    Wahl, E. R.; Schoelzel, C.

    2010-12-01

    Paleoenvironmental reconstruction from fossil pollen often attempts to take advantage of the rich taxonomic diversity in such data. Here, a taxonomically "reduced-space" reconstruction model is explored that would be parsimonious in introducing parameters needing to be estimated within a Bayesian Hierarchical Modeling context. This work involves a refinement of the traditional pollen ratio method. This method is useful when one (or a few) dominant pollen type(s) in a region have a strong positive correlation with a climate variable of interest and another (or a few) dominant pollen type(s) have a strong negative correlation. When, e.g., counts of pollen taxa a and b (r >0) are combined with pollen types c and d (r <0) to form ratios of the form (a + b) / (a + b + c + d), an appropriate estimation form is the binomial logistic generalized linear model (GLM). The GLM can readily model this relationship in the forward form, pollen = g(climate), which is more physically realistic than inverse models often used in paleoclimate reconstruction [climate = f(pollen)]. The specification of the model is: rnum Bin(n,p), where E(r|T) = p = exp(η)/[1+exp(η)], and η = α + β(T); r is the pollen ratio formed as above, rnum is the ratio numerator, n is the ratio denominator (i.e., the sum of pollen counts), the denominator-specific count is (n - rnum), and T is the temperature at each site corresponding to a specific value of r. Ecological and empirical screening identified the model (Spruce+Birch) / (Spruce+Birch+Oak+Hickory) for use in temperate eastern N. America. α and β were estimated using both "traditional" and Bayesian GLM algorithms (in R). Although it includes only four pollen types, the ratio model yields more explained variation ( 80%) in the pollen-temperature relationship of the study region than a 64-taxon modern analog technique (MAT). Thus, the new pollen ratio method represents an information-rich, reduced space data model that can be efficiently employed in

  4. IgA and IgM cytoplastic inclusions in a series of cases of chronic lymphocytic leukaemia.

    PubMed Central

    Cawley, J C; Smith, J; Goldstone, A H; Emmines, J; Hamblin, J; Hough, L

    1976-01-01

    Seventy-two cases of typical chronic lymphocytic leukaemia were screened by electron microscopy for the presence of intracytoplasmic immunoglobulin crystals. Immunoglobulin inclusions were found in four cases. Immunofluorescent studies showed that the inclusions contained IgA in two cases and IgM in the other two patients. Lambda light chain specificity was demonstrated in all four cases. The ultrastructure of the inclusions was identical in each patient except that in one of the IgA cases the inclusions were found in the perinuclear cistern in addition to the more usual location within cisternae of rough endoplasmic reticulum. Surface immunofluorescence showed mu heavy chains in the two cases displaying IgM crystal formation, but in the two IgA patients, no alpha heavy chains were demonstrable at the cell surface. The possible significance of these findings is discussed in relation to the existing literature. PMID:816582

  5. Corn pollen polysaccharides: composition of radiation-resistant nutrients and bioactivity

    NASA Astrophysics Data System (ADS)

    Lu, Weihong; Wenxin, Gao; Sun, Yeqing

    Corn pollen contains significant levels of free amino acids and protein, which greatly contribute to the biological function of corn pollen. However, to date there is no report in either China or abroad on research regarding the specific radiation-resistant composition in corn pollen includ-ing pollen polysaccharide. Reports on corn pollen polysaccharide have been mostly focused on immunological competence and anti-tumor functions. This study emphasized the optimization of the technical conditions for the extraction of corn pollen polysaccharide and the analysis of the corn pollen polysaccharide's structure. On that basis, we have developed in vitro experi-ments with corn pollen polysaccharide and report on its antioxidant functional activity. Our innovation lies in defining the specific composition of the radiation-resistant nutrients and active compounds as well as identifying the structure of the active compounds. We have successfully separated the active radiation-resistant functional factors, which are of great significance for astronauts and other special groups. Our results lay the groundwork for further research and development of corn pollen polysaccharide and ingredient technology.

  6. Bee Pollen-Induced Anaphylaxis: A Case Report and Literature Review.

    PubMed

    Choi, Jeong Hee; Jang, Young Sook; Oh, Jae Won; Kim, Cheol Hong; Hyun, In Gyu

    2015-09-01

    Bee pollen is pollen granules packed by honey bees and is widely consumed as natural healthy supplements. Bee pollen-induced anaphylaxis has rarely been reported, and its allergenic components have never been studied. A 40-year-old male came to the emergency room with generalized urticaria, facial edema, dyspnea, nausea, vomiting, abdominal pain, and diarrhea 1 hour after ingesting one tablespoon of bee pollen. Oxygen saturation was 91%. His symptoms resolved after injection of epinephrine, chlorpheniramine, and dexamethasone. He had seasonal allergic rhinitis in autumn. Microscopic examination of the bee pollen revealed Japanese hop, chrysanthemum, ragweed, and dandelion pollens. Skin-prick with bee pollen extracts showed positive reactions at 0.1 mg/mL (A/H ratio > 3+). Serum specific IgE to ragweed was 25.2, chrysanthemum 20.6, and dandelion 11.4 kU/L; however, Japanese hop, honey-bee venom and yellow-jacket venom were negative (UniCAP®, Thermo Fisher Scientific, Uppsala, Sweden). Enzyme-linked immunosorbent assay (ELISA) confirmed serum specific IgE to bee-pollen extracts, and an ELISA inhibition assay for evaluation of cross-allergenicity of bee pollen and other weed pollens showed more than 90% of inhibition with chrysanthemum and dandelion and ~40% inhibition with ragweed at a concentration of 1 μg/mL. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE-immunoblot analysis revealed 9 protein bands (11, 14, 17, 28, 34, 45, 52, 72, and 90 kDa) and strong IgE binding at 28-34 kDa, 45 and 52 kDa. In conclusion, healthcare providers should be aware of the potential risk of severe allergic reactions upon ingestion of bee pollen, especially in patients with pollen allergy. PMID:25749764

  7. Presence of secretory IgA in human periapical lesions.

    PubMed

    Torres, J O; Torabinejad, M; Matiz, R A; Mantilla, E G

    1994-02-01

    The concentration of secretory IgA in fluids present in the canals of 33 teeth was determined by the rocket immunoelectrophoresis technique. Except for the presence or absence of communication between the oral cavity and the root canals of the affected teeth, no other clinical finding showed significant statistical correlation with the presence of secretory IgA. The canals which were open to the oral flora had significantly higher concentrations of secretory IgA. Leaving canals open to the oral cavity may result in formation of periapical cysts. PMID:8006572

  8. The Arabidopsis KINβγ Subunit of the SnRK1 Complex Regulates Pollen Hydration on the Stigma by Mediating the Level of Reactive Oxygen Species in Pollen

    PubMed Central

    Zhao, Ting Ting; Li, Fei; Jia, Xiao Na; Zhao, Xin-Ying; Zhang, Xian Sheng

    2016-01-01

    Pollen–stigma interactions are essential for pollen germination. The highly regulated process of pollen germination includes pollen adhesion, hydration, and germination on the stigma. However, the internal signaling of pollen that regulates pollen–stigma interactions is poorly understood. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex which plays important roles in the regulation of plant development. Here, we showed that KINβγ was a cytoplasm- and nucleus-localized protein in the vegetative cells of pollen grains in Arabidopsis. The pollen of the Arabidopsis kinβγ mutant could not germinate on stigma, although it germinated normally in vitro. Further analysis revealed the hydration of kinβγ mutant pollen on the stigma was compromised. However, adding water to the stigma promoted the germination of the mutant pollen in vivo, suggesting that the compromised hydration of the mutant pollen led to its defective germination. In kinβγ mutant pollen, the structure of the mitochondria and peroxisomes was destroyed, and their numbers were significantly reduced compared with those in the wild type. Furthermore, we found that the kinβγ mutant exhibited reduced levels of reactive oxygen species (ROS) in pollen. The addition of H2O2 in vitro partially compensated for the reduced water absorption of the mutant pollen, and reducing ROS levels in pollen by overexpressing Arabidopsis CATALASE 3 resulted in compromised hydration of pollen on the stigma. These results indicate that Arabidopsis KINβγ is critical for the regulation of ROS levels by mediating the biogenesis of mitochondria and peroxisomes in pollen, which is required for pollen–stigma interactions during pollination. PMID:27472382

  9. The glycosylation and structure of human serum IgA1, Fab, and Fc regions and the role of N-glycosylation on Fcα receptor interactions.

    PubMed

    Mattu, T S; Pleass, R J; Willis, A C; Kilian, M; Wormald, M R; Lellouch, A C; Rudd, P M; Woof, J M; Dwek, R A

    1998-01-23

    The human serum immunoglobulins IgG and IgA1 are produced in bone marrow and both interact with specific cellular receptors that mediate biological events. In contrast to IgA1, the glycosylation of IgG has been well characterized, and its interaction with various Fc receptors (Fc Rs) has been well studied. In this paper, we have analyzed the glycosylation of IgA1 and IgA1 Fab and Fc as well as three recombinant IgA1 molecules, including two N-glycosylation mutants. Amino acid sequencing data of the IgA1 Fc O-glycosylated hinge region indicated that O-glycans are located at Thr228, Ser230, and Ser232, while O-glycan sites at Thr225 and Thr236 are partially occupied. Over 90% of the N-glycans in IgA1 were sialylated, in contrast to IgG, where < 10% contain sialic acid. This paper contains the first report of Fab glycosylation in IgA1, and (in contrast to IgG Fab, which contains only N-linked glycans) both N- and O-linked oligosaccharides were identified. Analysis of the N-glycans attached to recombinant IgA1 indicated that the Cα 2 N-glycosylation site contained mostly biantennary glycans, while the tailpiece site, absent in IgG, contained mostly triantennary structures. Further analysis of these data suggested that processing at one Fc N-glycosylation site affects the other. Neutrophil Fcα R binding studies, using recombinant IgA1, indicated that neither the tailpiece region nor the N-glycans in the C alpha 2 domain contribute to IgA1-neutrophil Fcα R binding. This contrasts with IgG, where removal of the Fc N-glycans reduces binding to the Fcγ R. The primary sequence and disulfide bond pattern of IgA1, together with the crystal structures of IgG1 Fc and mouse IgA Fab and the glycan sequencing data, were used to generate a molecular model of IgA1. As a consequence of both the primary sequence and S-S bond pattern, the N-glycans in IgA1 Fc are not confined within the inter-α-chain space. The accessibility of the Cα 2 N-glycans provides an explanation for the

  10. LeSTIG1, an extracellular binding partner for the pollen receptor kinases LePRK1 and LePRK2, promotes pollen tube growth in vitro.

    PubMed

    Tang, Weihua; Kelley, Dior; Ezcurra, Inés; Cotter, Robyn; McCormick, Sheila

    2004-08-01

    As pollen tubes grow through the pistil they are thought to perceive and respond to diverse signals. The tomato pollen-specific receptor kinases LePRK1 and LePRK2 might participate in signaling during pollen tube growth. We previously showed that the extracellular domain of LePRK2 interacts with a pollen protein, LAT52, before but not after pollen germination. To determine whether LePRK2 might have different binding partner(s) after pollen germination, we characterized two more proteins that, like LAT52, were identified in yeast two-hybrid screens using the extracellular domains of LePRK1 and LePRK2 as baits. We show that LeSHY, a leucine-rich repeat protein from pollen, and LeSTIG1, a small cysteine-rich protein from pistil, can bind the extracellular domains of both LePRK1 and LePRK2 in vitro. In vitro binding assays with the extracellular domain of LePRK2 suggested that LeSTIG1 could displace binding of LAT52, consistent with the idea that LePRK1 and LePRK2 might interact with different ligands at different stages of pollen tube growth. Exogenous LeSTIG1 promotes pollen tube growth in vitro. The interaction of these pollen kinases with LeSTIG1 supports the notion that LePRK1 and LePRK2 are involved in mediating pollen-pistil interactions. PMID:15255864

  11. Seasonal variation of birch and grass pollen loads and allergen release at two sites in the German Alps

    NASA Astrophysics Data System (ADS)

    Jochner, Susanne; Lüpke, Marvin; Laube, Julia; Weichenmeier, Ingrid; Pusch, Gudrun; Traidl-Hoffmann, Claudia; Schmidt-Weber, Carsten; Buters, Jeroen T. M.; Menzel, Annette

    2015-12-01

    Less vegetated mountainous areas may provide better conditions for allergy sufferers. However, atmospheric transport can result in medically relevant pollen loads in such regions. The majority of investigations has focused on the pollen load, expressed as daily averages of pollen per cubic meter of air (pollen grains/m³); however, the severity of allergic symptoms is also determined by the actual allergen content of this pollen, its pollen potency, which may differ between high and low altitudes. We analysed airborne birch and grass pollen concentrations along with allergen content (birch: Bet v 1, grass: Phl p 5) at two different altitudes (734 and 2650 m a.s.l.) in the Zugspitze region (2009-2010). Back-trajectories were calculated for the high altitude site and for specific days with abrupt increases in pollen potency. We observed several days with medically relevant pollen concentrations at the highest site. In addition, a few days with pollen were not associated with allergens and vice versa. The calculated seasonal mean allergen release per pollen grain was 1.8-3.3 pg Bet v 1 and 5.7 pg Phl p 5 in the valley and 1.1-3.7 pg Bet v 1 and 0.7-1.5 pg Phl p 5 at the high altitude site. Back-trajectories revealed that high pollen potency at the higher site was generally associated with south-westerly to south-easterly (birch), or northerly (grass) wind directions. By investigating days with sudden increases in pollen potency, however, it was difficult to draw definitive conclusions on long- or short-range transport. Our findings suggest that people allergic to pollen might suffer less at higher altitudes and further indicate that a risk assessment relying on the actual concentration of airborne pollen does not necessarily reflect the actual allergy exposure of individuals.

  12. Saliva and sera IgA and IgG in Egyptian Giardia-infected children.

    PubMed

    El-Gebaly, Naglaa Saad M; Halawa, Eman Fawzy; Moussa, Hanaa M Ezzat; Rabia, Ibrahim; Abu-Zekry, Maha

    2012-08-01

    Giardiasis is a gastrointestinal infection of wide distribution that is more prevalent in childhood. Easy and rapid diagnosis of giardiasis is essential for reduction of this infection. This cross-sectional study included 62 children in which collection of saliva, stool and serum samples was performed. An enzyme-linked immunosorbent assay (ELISA) technique was evaluated to detect IgA and IgG responses in both saliva and serum samples. Twenty-two children were positive for Giardia duodenalis infection by direct examination of faecal specimens, 20 non-infected and 20 infected with other parasites. Salivary and serum IgA and IgG responses against G. duodenalis infection were significantly higher in Giardia parasitized than non-Giardia parasitized children (p < 0.001). This concludes that specific salivary IgA may serve as a diagnostic tool and specific salivary IgG as a screening tool in monitoring the exposure of various populations to Giardia duodenalis. The advantage of salivary assays over serum immunoglobulin assay is being easy and non-invasive in sampling technique which is important especially for young children. PMID:22402609

  13. Molecular Insights into the Pathogenesis of IgA Nephropathy.

    PubMed

    Robert, Thomas; Berthelot, Laureline; Cambier, Alexandra; Rondeau, Eric; Monteiro, Renato C

    2015-12-01

    Immunoglobulin IgA nephropathy (IgAN) is the leading form of primary glomerulonephritis associated with end-stage renal failure, requiring either dialysis or renal transplantation. Microscopic hematuria and proteinuria are the most common presentations, and mesangial cell proliferation with IgA deposition are found in renal biopsies. There is growing evidence that IgAN is an immune complex (IC)-mediated disease. To date, three key molecules have been implicated in IC formation, correlating with disease progression/recurrence after transplantation: galactose-deficient IgA1 (Gd-IgA1), IgG anti-Gd-IgA1 antibodies, and soluble CD89 (an Fc receptor for IgA). This review examines recent data on the role of these molecular players in IgAN. Understanding these factors is essential because such knowledge could lead to improved strategies for the future management of patients with IgAN. PMID:26614735

  14. Pollen Forecast and Dispersion Modelling

    NASA Astrophysics Data System (ADS)

    Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

    2014-05-01

    The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

  15. Pollen taphonomy in a canyon stream

    NASA Astrophysics Data System (ADS)

    Fall, Patricia L.

    1987-11-01

    Surface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae- Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

  16. [Scarring linear IgA dermatosis in the adult].

    PubMed

    Kurz, K; Mahrle, G

    1986-10-15

    A 54-year-old woman had a six-months history of a scarring blistering disease with clinical signs of dermatitis herpetiformis and bullous pemphigoid. Direct immunofluorescence examination showed homogeneously linear deposits of IgA along the dermo-epidermal junction. Electron microscopic studies revealed blistering above and beneath the lamina densa. Referring to this new case of a scarring linear IgA disease we discuss some other forms of scarring bullous diseases in adults. PMID:3541412

  17. Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)

    PubMed Central

    Timerman, David; Greene, David F.; Urzay, Javier; Ackerman, Josef D.

    2014-01-01

    In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind–stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts directly on stamens in the cosmopolitan, wind-pollinated weed, Plantago lanceolata, causing resonant vibrations that release episodic bursts of pollen grains. In laboratory experiments, we show that stamens have mechanical properties corresponding to theoretically predicted ranges for turbulence-driven resonant vibrations. The mechanical excitation of stamens at their characteristic resonance frequency caused them to resonate, shedding pollen vigorously. The characteristic natural frequency of the stamens increased over time with each shedding episode due to the reduction in anther mass, which increased the mechanical energy required to trigger subsequent episodes. Field observations of a natural population under turbulent wind conditions were consistent with these laboratory results and demonstrated that pollen is released from resonating stamens excited by small eddies whose turnover periods are similar to the characteristic resonance frequency measured in the laboratory. Turbulence-driven vibration of stamens at resonance may be a primary mechanism for pollen shedding in wind-pollinated angiosperms. The capacity to release pollen in wind can be viewed as a primary factor distinguishing animal- from wind-pollinated plants, and selection on traits such as the damping ratio and flexural rigidity may be of consequence in evolutionary transitions between pollination systems. PMID:25297315

  18. Genome-Wide Analyses Suggest Mechanisms Involving Early B-Cell Development in Canine IgA Deficiency

    PubMed Central

    Frankowiack, Marcel; Kierczak, Marcin; Bergvall, Kerstin; Axelsson, Erik; Tintle, Linda; Marti, Eliane; Roosje, Petra; Leeb, Tosso; Hedhammar, Åke; Hammarström, Lennart; Lindblad-Toh, Kerstin

    2015-01-01

    Immunoglobulin A deficiency (IgAD) is the most common primary immune deficiency disorder in both humans and dogs, characterized by recurrent mucosal tract infections and a predisposition for allergic and other immune mediated diseases. In several dog breeds, low IgA levels have been observed at a high frequency and with a clinical resemblance to human IgAD. In this study, we used genome-wide association studies (GWAS) to identify genomic regions associated with low IgA levels in dogs as a comparative model for human IgAD. We used a novel percentile groups-approach to establish breed-specific cut-offs and to perform analyses in a close to continuous manner. GWAS performed in four breeds prone to low IgA levels (German shepherd, Golden retriever, Labrador retriever and Shar-Pei) identified 35 genomic loci suggestively associated (p <0.0005) to IgA levels. In German shepherd, three genomic regions (candidate genes include KIRREL3 and SERPINA9) were genome-wide significantly associated (p <0.0002) with IgA levels. A ~20kb long haplotype on CFA28, significantly associated (p = 0.0005) to IgA levels in Shar-Pei, was positioned within the first intron of the gene SLIT1. Both KIRREL3 and SLIT1 are highly expressed in the central nervous system and in bone marrow and are potentially important during B-cell development. SERPINA9 expression is restricted to B-cells and peaks at the time-point when B-cells proliferate into antibody-producing plasma cells. The suggestively associated regions were enriched for genes in Gene Ontology gene sets involving inflammation and early immune cell development. PMID:26225558

  19. Intermittent fasting promotes bacterial clearance and intestinal IgA production in Salmonella typhimurium-infected mice.

    PubMed

    Godínez-Victoria, M; Campos-Rodriguez, R; Rivera-Aguilar, V; Lara-Padilla, E; Pacheco-Yepez, J; Jarillo-Luna, R A; Drago-Serrano, M E

    2014-05-01

    The impact of intermittent fasting versus ad libitum feeding during Salmonella typhimurium infection was evaluated in terms of duodenum IgA levels, bacterial clearance and intestinal and extra-intestinal infection susceptibility. Mice that were intermittently fasted for 12 weeks or fed ad libitum were infected with S. typhimurium and assessed at 7 and 14 days post-infection. Next, we evaluated bacterial load in the faeces, Peyer's patches, spleen and liver by plate counting, as well as total and specific intestinal IgA and plasmatic corticosterone levels (by immunoenzymatic assay) and lamina propria IgA levels in plasma cells (by cytofluorometry). Polymeric immunoglobulin receptor, α- and J-chains, Pax-5 factor, pro-inflammatory cytokine (tumour necrosis factor-α and interferon-γ) and anti-inflammatory cytokine (transforming growth factor-β) mRNA levels were assessed in mucosal and liver samples (by real-time PCR). Compared with the infected ad libitum mice, the intermittently fasted infected animals had (1) lower intestinal and systemic bacterial loads; (2) higher SIgA and IgA plasma cell levels; (3) higher mRNA expression of most intestinal parameters; and (4) increased or decreased corticosterone levels on day 7 and 14 post-infection, respectively. No contribution of liver IgA was observed at the intestinal level. Apparently, the changes following metabolic stress induced by intermittent fasting during food deprivation days increased the resistance to S. typhimurium infection by triggering intestinal IgA production and presumably, pathogen elimination by phagocytic inflammatory cells. PMID:24612255

  20. SUN anchors pollen WIP–WIT complexes at the vegetative nuclear envelope and is necessary for pollen tube targeting and fertility

    PubMed Central

    Zhou, Xiao; Groves, Norman Reid; Meier, Iris

    2015-01-01

    LINC (linker of nucleoskeleton and cytoskeleton) complexes play an essential role in nuclear migration by connecting the nucleus to the cytoskeleton and/or motor proteins. Plant LINC complexes have recently been identified in Arabidopsis thaliana, with the inner nuclear membrane SUN and outer nuclear membrane WIP proteins comprising the first identified complex. A recent study identified a nuclear movement defect in Arabidopsis pollen vegetative nuclei linked to the outer nuclear envelope WIP and WIT proteins. However, the role that SUN proteins may play in pollen nuclear migration has yet to be addressed. To explore this question, a SUN2 lumenal domain that was targeted to the ER specifically in pollen was over-expressed. It is shown that the ER-targeted SUN2 lumenal domain was able to displace WIP and WIT proteins from the pollen vegetative nuclear envelope. Expression of this dominant-negative transgene led to impaired VN mobility, impaired pollen tube guidance, and defective pollen tube reception. The observed pollen defects are similar to phenotypes observed in a wip1-1 wip2-1 wip3-1 wit1-1 wit2-1 mutant. It is also shown that these defects were dependent on the KASH-binding function of the SUN2 lumenal domain. These data support a model where LINC complexes formed by SUN, WIP, and WIT at the VNE are responsible for VN migration and suggest an important function of SUN, WIP, and WIT in pollen tube guidance and reception. PMID:26409047

  1. Commercial Bee Pollen with Different Geographical Origins: A Comprehensive Approach

    PubMed Central

    Nogueira, Carla; Iglesias, Antonio; Feás, Xesus; Estevinho, Leticia M.

    2012-01-01

    Since the primordial of humanity, pollen has been considered a good source of nutrients and energy. Its promising healing properties have also been referred to. The present study aimed to characterize, for the first time, eight commercial pollens from Portugal and Spain available on the market studying the legislation on labeling, pollinic origin, physicochemical and microbiological analyses and identification of yeasts. Eleven botanical families were found amongst the samples. The most abundant family and the most dominant pollen was Cistaceae. The moisture content, ash, aw, pH, reducing sugars, carbohydrates, proteins, lipids and energy were analyzed and the specific parameters were within the specifications required by some countries with legislation regarding these parameters. Microbiologically commercial pollen showed acceptable safety for the commercial quality and hygiene. All samples showed negative results for toxigenic species. The microorganisms studied were aerobic mesophiles, yeasts and moulds, coliforms, Escherichia coli, Staphylococcus aureus, Salmonella and sulfite-reducing Clostridium. During the work, six yeasts species were isolated from pollen, with Rhodotorula mucilaginosa being the most abundant, as it was present in four samples. PMID:23109845

  2. Pollen mixing in pollen generalist solitary bees: a possible strategy to complement or mitigate unfavourable pollen properties?

    PubMed

    Eckhardt, Michael; Haider, Mare; Dorn, Silvia; Müller, Andreas

    2014-05-01

    Generalist herbivorous insects, which feed on plant tissue that is nutritionally heterogeneous or varies in its content of secondary metabolites, often benefit from dietary mixing through more balanced nutrient intake or reduced exposure to harmful secondary metabolites. Pollen is similarly heterogeneous as other plant tissue in its content of primary and secondary metabolites, suggesting that providing their offspring with mixed pollen diets might be a promising strategy for pollen generalist bees to complement nutrient imbalances or to mitigate harmful secondary metabolites of unfavourable pollen. In the present study, we compared larval performance of the pollen generalist solitary bee species Osmia cornuta (Megachilidae) on five experimental pollen diets that consisted of different proportions of unfavourable pollen diet of Ranunculus acris (Ranunculaceae) and favourable pollen diet of Sinapis arvensis (Brassicaceae). In addition, we microscopically analysed the pollen contained in the scopal brushes of field-collected females of O. cornuta and three closely related species to elucidate to what degree these pollen generalist bees mix pollen of different hosts in their brood cells. In striking contrast to a pure Ranunculus pollen diet, which had a lethal effect on most developing larvae of O. cornuta, larval survival, larval development time and adult body mass of both males and females remained nearly unaffected by the admixture of up to 50% of Ranunculus pollen diet to the larval food. Between 42% and 66% of all female scopal pollen loads analysed contained mixtures of pollen from two to six plant families, indicating that pollen mixing is a common behaviour in O. cornuta and the three related bee species. The present study provides the first evidence that the larvae of pollen generalist bees can benefit from the nutrient content of unfavourable pollen without being negatively affected by its unfavourable chemical properties if such pollen is mixed with

  3. Increased dimeric IgA-producing B cells in tonsils in IgA nephropathy determined by in situ hybridization for J chain mRNA.

    PubMed Central

    Harper, S J; Allen, A C; Béné, M C; Pringle, J H; Faure, G; Lauder, I; Feehally, J

    1995-01-01

    The origin of mesangial IgA deposits in IgA nephropathy (IgAN) remains obscure. A significant proportion of deposited immunoglobulin is dimeric (J chain-positive). Previous studies of J chain expression within lymphoid tissue in IgAN have utilized antibodies which other investigators have found to be non-specific. To address this problem, we have developed and in situ hybridization (ISH) method for the detection of J chain mRNA within IgA plasma cells. Tonsils from 12 patients with IgAN and 12 controls were studied using (i) non-isotopic ISH for J chain mRNA, and (ii) combined immunofluorescence (IF) and fluorescent ISH. J chain mRNA-positive cells were identified in germinal centres, and within the subepithelial and interfollicular zones. A greater number of J chain mRNA-positive cells were found in the germinal centres of patients (mean 57.7 +/- 4.6 cells/10(5) micron2) compared with controls (mean 36.9 +/- 3.5 cells/10(5) micron2) (P < 0.001). Combined IF and fluorescent ISH showed a greater proportion of J chain mRNA-positive interfollicular IgA cells in patient tonsils (32 +/- 3.4%) compared with controls (21 +/- 2.3%; P < 0.02). These results indicate a shift towards dimeric IgA production in the tonsils in IgAN. In addition, the finding of excess numbers of J chain-positive Iga-negative cells within germinal centres suggests that an abnormality may be present at the B cell differentiation stage before IgA switching. These results further highlight immune abnormalities within the tonsil as a central feature of abnormal polymeric IgA biology in this common form of glomerulonephritis. Images Fig. 1 Fig. 2 PMID:7664491

  4. Knockin' on pollen's door: live cell imaging of early polarization events in germinating Arabidopsis pollen

    PubMed Central

    Vogler, Frank; Konrad, Sebastian S. A.; Sprunck, Stefanie

    2015-01-01

    Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane. PMID:25954283

  5. Requirements for B7-CD28 costimulation in mucosal IgA responses: paradoxes observed in CTLA4-H gamma 1 transgenic mice.

    PubMed

    Gärdby, E; Lane, P; Lycke, N Y

    1998-07-01

    The block in the CD80/CD86-CD28/CTLA-4 pathway in CTLA4-H gamma 1 transgenic (Tg) mice results in strongly impaired systemic IgG immunity and failure to develop germinal center reactions. By contrast, here we report that mucosal immunity and IgA B cell differentiation are not affected by this block. We found abundant germinal centers and evidence of IgA switch differentiation in Peyer's patches, normal total IgA levels, and normal numbers of IgA-labeling cells in the gut mucosa. The distribution of B-1 and B-2 cells and the relative contribution of B-1 cells to the total IgA B cells were similar in Tg and wild-type mice. Despite this, oral immunizations with keyhole limpet hemocyanin plus cholera toxin adjuvant failed to stimulate Ag-specific mucosal IgA responses in CTLA4-H gamma 1 Tg mice. This was not due to a lack of adjuvant activity of cholera toxin in Tg mice, nor was this secondary to an inability to take up Ag from the gut lumen. Rather, CD4+ T cells stimulated by oral immunization in Tg mice appeared to be inappropriately primed, as evidenced by a significantly reduced level of CD40 ligand and CD44 expression and an increased expression of CD95 compared to those in wild-type mice. This study reveals a paradox in the regulation of mucosal IgA responses. PMID:9647206

  6. Microbiota regulate the ability of lung dendritic cells to induce IgA class-switch recombination and generate protective gastrointestinal immune responses

    PubMed Central

    Ruane, Darren; Chorny, Alejo; Lee, Haekyung; Faith, Jeremiah; Pandey, Gaurav; Shan, Meimei; Simchoni, Noa; Rahman, Adeeb; Garg, Aakash; Weinstein, Erica G.; Oropallo, Michael; Gaylord, Michelle; Ungaro, Ryan; Cunningham-Rundles, Charlotte; Alexandropoulos, Konstantina; Mucida, Daniel; Merad, Miriam; Cerutti, Andrea

    2016-01-01

    Protective immunoglobulin A (IgA) responses to oral antigens are usually orchestrated by gut dendritic cells (DCs). Here, we show that lung CD103+ and CD24+CD11b+ DCs induced IgA class-switch recombination (CSR) by activating B cells through T cell–dependent or –independent pathways. Compared with lung DCs (LDC), lung CD64+ macrophages had decreased expression of B cell activation genes and induced significantly less IgA production. Microbial stimuli, acting through Toll-like receptors, induced transforming growth factor-β (TGF-β) production by LDCs and exerted a profound influence on LDC-mediated IgA CSR. After intranasal immunization with inactive cholera toxin (CT), LDCs stimulated retinoic acid–dependent up-regulation of α4β7 and CCR9 gut-homing receptors on local IgA-expressing B cells. Migration of these B cells to the gut resulted in IgA-mediated protection against an oral challenge with active CT. However, in germ-free mice, the levels of LDC-induced, CT–specific IgA in the gut are significantly reduced. Herein, we demonstrate an unexpected role of the microbiota in modulating the protective efficacy of intranasal vaccination through their effect on the IgA class-switching function of LDCs. PMID:26712806

  7. Microbiota regulate the ability of lung dendritic cells to induce IgA class-switch recombination and generate protective gastrointestinal immune responses.

    PubMed

    Ruane, Darren; Chorny, Alejo; Lee, Haekyung; Faith, Jeremiah; Pandey, Gaurav; Shan, Meimei; Simchoni, Noa; Rahman, Adeeb; Garg, Aakash; Weinstein, Erica G; Oropallo, Michael; Gaylord, Michelle; Ungaro, Ryan; Cunningham-Rundles, Charlotte; Alexandropoulos, Konstantina; Mucida, Daniel; Merad, Miriam; Cerutti, Andrea; Mehandru, Saurabh

    2016-01-11

    Protective immunoglobulin A (IgA) responses to oral antigens are usually orchestrated by gut dendritic cells (DCs). Here, we show that lung CD103(+) and CD24(+)CD11b(+) DCs induced IgA class-switch recombination (CSR) by activating B cells through T cell-dependent or -independent pathways. Compared with lung DCs (LDC), lung CD64(+) macrophages had decreased expression of B cell activation genes and induced significantly less IgA production. Microbial stimuli, acting through Toll-like receptors, induced transforming growth factor-β (TGF-β) production by LDCs and exerted a profound influence on LDC-mediated IgA CSR. After intranasal immunization with inactive cholera toxin (CT), LDCs stimulated retinoic acid-dependent up-regulation of α4β7 and CCR9 gut-homing receptors on local IgA-expressing B cells. Migration of these B cells to the gut resulted in IgA-mediated protection against an oral challenge with active CT. However, in germ-free mice, the levels of LDC-induced, CT-specific IgA in the gut are significantly reduced. Herein, we demonstrate an unexpected role of the microbiota in modulating the protective efficacy of intranasal vaccination through their effect on the IgA class-switching function of LDCs. PMID:26712806

  8. Metabolic Syndrome in IgA Glomerulonephritis

    PubMed Central

    Kaartinen, Kati; Syrjänen, Jaana; Pörsti, Ilkka; Harmoinen, Aimo; Huhtala, Heini; Mustonen, Jukka

    2014-01-01

    Background/Aims Metabolic syndrome (MetS) may have an independent impact on the development of chronic kidney disease. This study examines the prevalence of MetS in subjects with IgA glomerulonephritis (IgAGN) and its impact on disease progression in a retrospective fashion. Patients and Methods Altogether, 174 subjects (104 males) were examined 11 years (first visit) after IgAGN diagnosis and again after 16 years (second visit; 144 subjects responded). Different glomerular filtration markers were utilized. The MetS criteria by Alberti et al. [Circulation 2009;120:1640-1645] were applied, in which the presence of any three of five risk factors (elevated waist circumference, triglycerides, glucose, existence of hypertension, or reduced high-density lipoprotein cholesterol) constitutes the diagnosis. Results The prevalence of MetS at the first visit was 39%, corresponding to that of the general Finnish population. In univariate analyses, MetS was significantly associated with the progression of IgAGN at the second visit. However, in multivariate analyses, the existence of MetS was not a significant prognostic determinant. Conclusion The number of subjects with MetS among IgAGN patients and the general population is equal in Finland. MetS does not seem to be an independent prognostic variable. PMID:25337083

  9. The Treatment of IgA Nephropathy

    PubMed Central

    Lai, Kar Neng; Leung, Joseph C.K.; Tang, Sydney C.W.

    2015-01-01

    Background IgA nephropathy (IgAN) is a very common glomerulonephritis worldwide. Nevertheless, treatment options for primary IgAN are still largely based on opinion or weak evidence. There is a lack of large randomized controlled trials (RCT) that provide a definitive immunosuppressive protocol for IgAN. The recent KDIGO Clinical Practice Guidelines for Glomerulonephritis have assigned low levels of evidence for almost all recommendations and suggestions related to this nephropathy. Summary In this article, we review different treatment options and emphasize that the key to therapeutic decision-making is the assessment of an individual's prognosis. The risk of disease progression is closely related to clinical parameters such as proteinuria, hypertension, and impaired glomerular filtration rate. For patients with minor urinary abnormalities, the mainstay of treatment is long-term regular follow-up to detect renal progression and hypertension. Optimized supportive care aiming to maintain proteinuria <1 g/day is preferred in the typical patient presenting with microhematuria, significant but nonnephrotic proteinuria, hypertension, and variable degrees of renal failure. The atypical patient with overt nephritic syndrome or rapidly progressive kidney injury that represents a vasculitic form of IgAN should be treated with immunosuppression. Finally, the variant of overlapping syndrome of IgAN and lipoid nephrosis that runs a good prognosis should be treated as lipoid nephrosis. Key Message The treatment of IgAN should be structured according to the clinical scenario.

  10. Antigenic heterogeneity of IgA anti-GBM disease: new renal targets of IgA autoantibodies.

    PubMed

    Ho, Julie; Gibson, Ian W; Zacharias, James; Fervenza, Fernando; Colon, Selene; Borza, Dorin-Bogdan

    2008-10-01

    Anti-glomerular basement membrane (anti-GBM) disease is an aggressive form of glomerulonephritis, usually mediated by immunoglobulin G (IgG) autoantibodies to the noncollagenous (NC1) domain of alpha 3(IV) collagen. Less is known about the target antigen(s) in patients with atypical anti-GBM disease involving IgA autoantibodies. We report a new case of IgA anti-GBM disease in a patient with a history of proliferative lupus nephritis who presented with increasing creatinine levels, proteinuria, and hematuria, but no clinical or serological evidence of lupus recurrence. Renal biopsy showed focal and segmental necrotizing glomerulonephritis with strong linear capillary loop IgA staining by means of immunofluorescence. Serological test results were negative for IgG or IgA autoantibodies against the alpha 3NC1 domain. By means of immunoblotting, IgA from patient serum bound to 38- to 48-kd antigens collagenase-solubilized from human GBM, but not to purified NC1 domains of GBM collagen IV. The target of patient's IgA autoantibodies thus was identified as a novel GBM antigen, distinct from the alpha 3NC1 domain or other known targets of anti-GBM IgA autoantibodies. Clinical resolution was attained by means of conventional treatment with steroids and cyclophosphamide. The diversity of antigens recognized by anti-GBM IgA autoantibodies highlights the importance of renal biopsy for the reliable diagnosis of this rare condition because conventional serological immunoassays likely would yield false-negative results. PMID:18752876