Conglutinin is a high molecular-weight lectin originally detected in bovine serum. It belongs to the family of collectins that bind sugar residues in a Ca(2+)-dependent manner and are effector molecules in innate immunity. Conglutinin appears to play an important role in immune defense mechanisms, showing antiviral and antibacterial activities when tested in vivo and in vitro. The present study evaluated the effect of conglutinin on the respiratory bursts in bovine peripheral phagocytes. Using nitroblue tetrazolium and hydrogen peroxide assays, we showed that sugar ligand-bound conglutinin stimulated the production of superoxide and H2O2 in granulocytes whereas the non-sugar-bound form of conglutinin inhibited these processes. These results indicate that both forms of conglutinin are able to interact with surface leukocyte receptors but have opposite effects on phagocytic activity. Our findings suggest that conglutinin bound to sugar residues on microbial surfaces can induce oxygen burst in phagocytes, and thereby mediates the elimination of pathogens and prevents the spread of infection.
Animals ; Cattle/*immunology ; Collectins/*pharmacology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Female ; Granulocytes/*drug effects/immunology ; Hydrogen Peroxide/immunology ; Immunity, Innate/drug effects/immunology ; Phagocytosis/immunology ; Reactive Oxygen Species/*immunology ; Respiratory Burst/*drug effects/immunology ; Serum Globulins/*pharmacology ; Statistics, Nonparametric ; Superoxides/immunology

The preliminary role of respiratory burst oxidase homolog (Rboh) in plant immune response is defined, but the exact function of OsRboh gene in rice immune response and its expression pattern is yet unclear. In order to clarify the role of OsRboh in rice immune response, we screened seven OsRboh genes from the latest rice genome annotation database. The result of tissue specific expression analysis demonstrated that OsRbohD was expressed only in spike and calli, and OsRbohE and OsRbohF were only expressed in calli. The rest of OsRboh genes were constitutively expressed in rice. In addition, the expression level of OsRboh gene family was analyzed in the rice leaves respectively treated with salicylic acid (SA), methyl jasmonic acid (MeJA) and Xanthomonas oryzae PV. oryzae (Xoo) PXO99 strain by Real-time PCR, and H2O2 content was also quantified by spectrophotometry after the three treatments. The result shows that the expression of OsRbohA, B, C and D was increased under the treatments of SA, the expression of OsRbohA, B, C and G was increased under the treatments of MeJA, and the expression of OsRbohA and OsRbohB was induced by Xoo PXO99 strain. However, the levels of expression and responsive times of these genes were different. Moreover, all three treatments led to H2O2 accumulation. These OsRboh genes have functional roles in rice native immune response.
Acetates ; pharmacology ; Amino Acid Sequence ; Cyclopentanes ; pharmacology ; Hydrogen Peroxide ; metabolism ; Molecular Sequence Data ; Multigene Family ; NADPH Oxidases ; genetics ; immunology ; metabolism ; Oryza ; genetics ; immunology ; metabolism ; Oxylipins ; pharmacology ; Plant Immunity ; genetics ; Salicylic Acid ; pharmacology ; Xanthomonas ; pathogenicity

The brain is particularly vulnerable to oxygen free radicals, and these radicals have been implicated in the pathology of several neurological disorders. In this study, the modulation of TNF-related apoptosis-inducing ligand (TRAIL) expression by oxidative stress was shown in LN215 cells, an astroglioma cell line. Hydrogen peroxide (H2O2) treatment increased TRAIL expression in LN215 cells and H2O2-induced TRAIL augmented apoptosis in Peer cells, a cell line sensitive to TRAIL- mediated cell death. Our findings suggest that the upregulation of TRAIL in astroglial cells may abrogate immune cell effector functions.
*Up-Regulation ; TNF-Related Apoptosis-Inducing Ligand/*biosynthesis ; T-Lymphocytes/*metabolism ; Ribonucleases/metabolism ; Oxidative Stress ; Immunosuppressive Agents/pharmacology ; Hydrogen Peroxide/*pharmacology ; Humans ; *Gene Expression Regulation, Neoplastic ; Cyclosporine/pharmacology ; Cell Line, Tumor ; Astrocytes/*metabolism ; *Apoptosis ; Anoxia ; Allergy and Immunology

Prostaglandin E2(PGE2) has been implicated as an immunosuppressive agent and plasma levels of PGE2 are elevated in patients sustaining thermal injury. We examined the effect of 10(-7) M prostaglandin E2(PGE2) on human polymorphonuclear leukocytes (PMN) to determine whether it directly inhibits stimulated responses of these cells. At this concentration, PGE2 alone was incapable of stimulating PMN intracellular hydrogen peroxide production (indirectly assayed by fluorescence of 2',7'ichlorofluorescin) or expression of the PMN CD11b/CD16 surface glycoproteins. PMN incubated in the presence of the soluble stimul phorbol myristate acetate(PMA, 100 ng/ml) or recombinant human C5a(rHC5a, 10(-8) M) generated significant amounts of hydrogen peroxide, increased their CD11b expression and decreased their CD16 expression. Pre-incubation of cells with PGE2 caused significant inhibition of all the observed changes stimulated by rHC5a. In contrast, events stimulated by PMA were not affected by preincubation of cells with PGE2. We conclude that PGE2, in concentrations identical to those found in the plasma of patients with burn injuries, is capable of selectively inhibiting some stimulated events and phenotypic expression of PMN in vitro study.
Dinoprostone/*pharmacology ; Dose-Response Relationship, Drug ; Human ; Hydrogen Peroxide/metabolism ; Immunosuppressive Agents/*pharmacology ; Macrophage-1 Antigen/biosynthesis ; Neutrophils/*drug effects/immunology ; Receptors, IgG/biosynthesis ; Support, Non-U.S. Gov't ; Temperature ; Tetradecanoylphorbol Acetate/pharmacology ; Time Factors

Inflammatory responses are strictly regulated by coordination of pro-inflammatory and anti-inflammatory mediators. Interleukin-4 (IL-4) and interleukin-10 (IL-10) have typically the biologic anti-inflammatory effects on monocytes, but uncertain effects on polymorphonuclear leukocytes (PMNs). The PMNs are the first line of cellular response for host defense during acute inflammation. To modify hyper-inflammatory reaction with biologic anti-inflammatory mediators, we have determined the biologic anti-inflammatory activities of IL-4 and IL-10 on human PMNs. Human PMNs were pretreated with IL-4 or IL-10 and then stimulated with formyl methionyl leucyl phenylalanine (fMLP) for times indicated. The level of H2O2, interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) were determined in the each cell free supernatants. fMLP plays the role of a typical pro-inflammatory agent and, at least in determined conditions, down-regulated TNF release. IL-4 acts as an anti-inflammatory mediator but IL-10 did not show its anti-inflammatory activities on fMLP-stimulated human PMNs. IL-4 and IL-10 have different anti-inflammatory mechanisms. Perhaps, IL-10 needs co-factors to act as an anti-inflammatory mediator.
Cells, Cultured ; Humans ; Hydrogen Peroxide/metabolism ; Interleukin-10/*pharmacology ; Interleukin-4/*pharmacology ; Interleukin-8/metabolism ; Intracellular Fluid ; N-Formylmethionine Leucyl-Phenylalanine/pharmacology ; Neutrophils/cytology/*drug effects/immunology ; Tumor Necrosis Factor-alpha/metabolism

OBJECTIVETo provide the basal data for artificial cross breeding of Chinese herb Salvia miltiorrhiza from 7 provinces in China and its 4 relatives.

METHODThe pollen viability was evaluated by TTC (2, 3, 5-triphenylte trazolium chloride) test and the stigma receptivity was evaluated by benzidine-H2O2 method.

RESULTThe pollen viability of S. miltiorrhiza from 6 provinces in China and its 4 relatives deceased during time of pollen shedding. Their highest pollen viability was in 2 or 3 days after blooming. But the pollen viability of S. miltiorrhiza (wild and culture) from Hean province in China declined with time after blooming. The most obvious variation of the pollen viability was in S. miltiorrhiza from Shanxi province (RSD 71.3% ) and the least was in wild S. miltiorrhiza from Henan province (RSD 12.4%). The highest average pollen viability was wild S. miltiorrhiza (72.3%) from Henan province while the lowest was S. yunnanensis (38.8%). The stigmas of all the accessions had receptivity when blooming. The stigma receptivity of S. brevilabra was strong in 2 to 4 days after blooming, while the others had less change after blooming. The life span of pollen grains and stigmas could be maintained from 3 to 5 days.

CONCLUSIONThe optimum artificial pollination time of S. miltiorrhiza and its relatives was 2 to 3 days after blooming.

China ; Christianity ; Chromosomes, Plant ; physiology ; DNA, Plant ; analysis ; Flowers ; growth & development ; physiology ; Genetic Variation ; Genetics, Population ; Hydrogen Peroxide ; pharmacology ; Plant Infertility ; physiology ; Plant Proteins ; genetics ; Pollen ; Pollination ; immunology ; physiology ; Polyploidy ; Salvia miltiorrhiza ; physiology

BACKGROUNDbeta-glucan is the major structure component of Candida albicans (C. albicans) cell wall. It has been demonstrated that Dectin-1 as the principal C-type lectin pattern-recognition receptor (PRR) can recognize fungal beta-glucan and induce immune responses. In this study, we sought to clarify whether insoluble beta-glucan from the cell wall of C. albicans (CaIG) could induce immune responses in human THP-1 monocytes (a human acute monocytic leukemia cell line) and to determine the underlying mechanisms.

METHODSHuman THP-1 monocytes were challenged with CaIG in vitro. The mRNA expression of Dectin-1, Toll-like receptors (TLR2), proinflammatory cytokine (TNF-alpha) and chemokine (IL-8) was assayed by real-time reverse transcription polymerase chain reaction (RT-PCR). The secretion of TNF-a and IL-8 were measured by enzyme-linked immunosorbent assay (ELISA). H(2)O(2) release was determined by microplate fluorescent assay. Western blotting was used to analyze IkappaB-a phosphorylation and degradation.

RESULTSExposure of THP-1 monocytes to CaIG led to increased gene expression and secretion of TNF-alpha and IL-8. CaIG induced H(2)O(2) release in a time-dependent manner. CaIG hydrolyzed with zymolyase failed to induce gene expression and secretion of TNF-alpha, IL-8 and H(2)O(2) release. CaIG up-regulated the mRNA of Dectin-1, whereas the mRNA level of TLR2 was not altered. THP-1 monocytes challenged with CaIG resulted in the activation of NF-kappaB in a time-dependent manner. Dectin-1 inhibitor laminarin blocked the CaIG-induced production of TNF-alpha and H(2)O(2) in THP-1 monocytes, but no such effect was observed in pretreatment with anti-TLR2 neutralizing antibody and the LPS inhibitor (polymyxin B).

CONCLUSIONCaIG may play a role in activation of immune responses in human THP-1 cells through Dectin-1, not TLR2.

Blotting, Western ; Candida albicans ; metabolism ; Cell Line, Tumor ; Cell Wall ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Humans ; Hydrogen Peroxide ; metabolism ; Interleukin-8 ; genetics ; metabolism ; Lectins, C-Type ; Membrane Proteins ; genetics ; metabolism ; Monocytes ; drug effects ; immunology ; metabolism ; Nerve Tissue Proteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Toll-Like Receptor 2 ; genetics ; Tumor Necrosis Factor-alpha ; genetics ; metabolism ; beta-Glucans ; pharmacology

Down syndrome critical region 1 (DSCR1), an oxidative stress-response gene, interacts with calcineurin and represses its phosphatase activity. Recently it was shown that hydrogen peroxide inactivates calcineurin by proteolytic cleavage. Based on these facts, we investigated whether oxidative stress affects DSCR1-mediated inactivation of calcineurin. We determined that overexpression of DSCR1 leads to increased proteolytic cleavage of calcineurin. Convertsely, knockdown of DSCR1 abolished calcineurin cleavage upon treatment with hydrogen peroxide. The PXIIXT motif in the COOH-terminus of DSCR1 is responsible for both binding and cleavage of calcineurin. The knockdown of overexpressed DSCR1 in DS fibroblast cells also abrogated calcineurin proteolysis by hydrogen peroxide. These results suggest that DSCR1 has the ability to inactivate calcineurin by inducing proteolytic cleavage of calcineurin upon oxidative stress.
Adenoviridae/genetics ; Adult ; Animals ; Calcineurin/antagonists & inhibitors/*metabolism ; Cells, Cultured ; Chromatin Immunoprecipitation ; Down Syndrome/*metabolism/pathology ; Fibroblasts/metabolism/pathology ; Humans ; Hydrogen Peroxide/pharmacology ; Immunoglobulin G/immunology ; Intracellular Signaling Peptides and Proteins/*physiology ; Male ; Mice ; Mice, Inbred ICR ; Muscle Proteins/*physiology ; Neuroblastoma/genetics/metabolism/pathology ; Neurons/cytology/metabolism ; Oxidants/pharmacology ; Oxidative Stress ; Peptide Fragments/immunology ; RNA, Messenger/genetics/metabolism ; RNA, Small Interfering/pharmacology ; Rabbits ; Reverse Transcriptase Polymerase Chain Reaction ; Skin/pathology ; Young Adult