Hemopoietic cell expression of the chemokine decoy receptor D6 is dynamic and regulated by GATA1

D6 scavenges inflammatory chemokines and is essential for the regulation of inflammatory and immune responses. Mechanisms explaining the cellular basis for D6 function have been based on D6 expression by lymphatic endothelial cells. In this study, we demonstrate that functional D6 is also expressed by murine and human hemopoietic cells and that this expression can be regulated by pro- and anti-inflammatory agents. D6 expression was highest in B cells and dendritic cells (DCs). In myeloid cells, LPS down-regulated expression, while TGF-beta up-regulated expression. Activation of T cells with anti-CD3 and soluble CD28 up-regulated mRNA expression 20-fold, while maturation of human macrophage and megakaryocyte precursors also up-regulated D6 expression. Competition assays demonstrated that chemokine uptake was D6 dependent in human leukocytes, whereas mouse D6-null cells failed to uptake and clear inflammatory chemokines. Furthermore, we present evidence indicating that D6 expression is GATA1 dependent, thus explaining D6 expression in myeloid progenitor cells, mast cells, megakaryocytes, and DCs. We propose a model for D6 function in which leukocytes, within inflamed sites, activate D6 expression and thus trigger resolution of inflammatory responses. Our data on D6 expression by circulating DCs and B cells also suggest alternative roles for D6, perhaps in the coordination of innate and adaptive immune responses. These data therefore alter our models of in vivo D6 function and suggest possible discrete, and novel, roles for D6 on lymphatic endothelial cells and leukocytes.     

A new geometric biclustering algorithm based on the Hough transform for analysis of large-scale microarray data

Biclustering is an important tool in microarray analysis when only a subset of genes co-regulates in a subset of conditions. Different from standard clustering analyses, biclustering performs simultaneous classification in both gene and condition directions in a microarray data matrix. However, the biclustering problem is inherently intractable and computationally complex. In this paper, we present a new biclustering algorithm based on the geometrical viewpoint of coherent gene expression profiles. In this method, we perform pattern identification based on the Hough transform in a column-pair space. The algorithm is especially suitable for the biclustering analysis of large-scale microarray data. Our studies show that the approach can discover significant biclusters with respect to the increased noise level and regulatory complexity. Furthermore, we also test the ability of our method to locate biologically verifiable biclusters within an annotated set of genes.     

Detection and taxonomic placement of endophytic fungi within frond tissues of Livistona chinensis based on rDNA sequences.

The 5.8S gene and flanking internal transcribed spacers (ITS1 and ITS2) of the rDNA were amplified from total DNA extracted from frond tissues of Livistona chinensis with universal and fungal-specific primers. These amplified fragments were cloned and sequenced. Phylogenetic analysis based on the 5.8S gene sequences indicated that the six clone sequences obtained were of different origins. Five sequences, P1-9, P2-6, P4-4, P4-5, and P4-7, belonged to the fungi and one sequence, P3-2, belonged to the plants. P1-9 was inferred to belong to the Basidiomycota based on the phylogenetic analysis of the 5.8S gene sequences but could not be identified to lower taxonomic levels. Further identification of the other four fungal clones to lower taxonomic levels was attempted based on phylogenetic analysis and sequence comparison of both the conserved 5.8S gene and the variable ITS regions. The origin of P2-6 was identified to be Glomerella and its anamorph Colletotrichum, the origins of P4-5 and P4-7 were Mycosphaerella and its anamorph Cladosporium, and the origin of P4-4 was the Herpotrichiellaceae. The direct approach to detection and taxonomic placement of endophytic fungi within host tissue without the need for conventional in vitro culturing is discussed.     

Fouling of microfiltration membranes by broth-free antifoam agents

The fouling tendencies of seven commercial antifoam agents used with microfiltration membranes were investigated in a stirred cell. Parameters such as viscosity, oil droplet size distribution, contact angle, work of adhesion (W(a)), membrane type, operating pressure, and feed concentration were examined. The results show that a silicone-based antifoam, G832, gave a significantly lower flux (相似文献   

Regulation of the immune response by antibody. II. The effects of different classes of passive guinea pig antibody on humoral and cell-mediated immunity in rats

The ability of different classes of passively administered guinea pig antibody (γ1, γ2, and IgM) to regulate humoral and cell-mediated immunity to flagellin, polymerized flagellin (POL), and sheep red blood cells (SRBC) was investigated in rats. It was found that at high concentrations, all classes of antibody suppressed the primary antibody responses and usually enhanced the delayed-type hypersensitivity induced by the three antigens. With flagellin and SRBC, the different classes of passive antibody varied in their suppressing and enhancing properties, being in the order: γ2 > γ1 = IgM. At low concentrations, γ1 and IgM enhanced the primary antibody response and suppressed the delayed hypersensitivity induced by flagellin. Such an effect was not observed with either POL or SRBC. Priming for a secondary antibody response was less readily suppressed by all classes of passive antibody. The removal of macrophage cytophilic antibody from γ2 converted this antibody to a preparation (γ2 absorbed) which had effects on humoral and cell-mediated immunity approaching that of γ1 antibody.