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1

New biodefense strategies by neutrophils

100%
Ishikawa F., Miyazaki S.
Archivum Immunologiae et Therapiae Experimentalis
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2005
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vol. 53
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issue 3
226-233
EN
Chemokines and other chemotactic factors induce neutrophils, macrophages, and dendritic cells to migrate to an inflammatory site and efficiently ingest and destroy infective microorganisms. Moreover, antigen-presenting cells, such as macrophages and dendritic cells, present the microbial antigens via major histocompatibility complex class II molecules, resulting in the activation of specific CD4 T cells. Since neutrophils have a short life-span and are highly susceptible to apoptosis, their role in antigen presentation has been questioned. However, various pro-inflammatory cytokines, such as interleukin (IL)-1, IL-6, tumor necrosis factor a, and interferon g, produced at the site of inflammation activate neutrophils and suppress apoptotic death. These cytokine-activated neutrophils show enhanced expression of cell surface molecules and become as competent as dendritic cells and macrophages in their ability of antigen presentation. Traditionally, neutrophils are known to be responsible for innate immunity, and recently they are also considered to be intimately associated with the establishment of acquired immunity. In the present review on the role of neutrophils we describe both classic innate and acquired immunity.
2

Immunomodulation by alpha(1)-proteinase inhibitor: lack of chemotactic effects of recombinant human alpha(1)-proteinase inhibitor from yeast on human peripheral blood granulocytes

88%
Mosheimer B., Alzner R., Wiedermann C. J.
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issue 6
399-403
EN
Introduction: Recombinant alpha(1)-proteinase inhibitor, clinically developed for inhalative augmentation therapy in patients with alpha(1)-proteinase inhibitor deficiency or cystic fibrosis, may directly contribute to leukocyte accumulation as it may function as a chemoattractant. The migratory effects of yeast-derived human recombinant alpha(1)-proteinase inhibitor on human peripheral blood neutrophils and eosinophils were therefore tested in vitro. Materials and Methods: Human peripheral blood leukocytes were prepared from forearm venous blood and tested for migration toward various preparations of yeast-derived recombinant alpha(1)-proteinase inhibitor in modified Boyden-chamber micropore filter assays. Results: No direct effects of yeast-derived recombinant human alpha(1)-proteinase inhibitor on in vitro migration of isolated neutrophils or eosinophils were seen. Conclusions: The lack of direct chemotactic effects of recombinant human alpha(1)-proteinase inhibitor despite anti-inflammatory effects in other biological activities of leukocytes may contribute to the preserved antibacterial defense mechanisms observed in patients under experimental augmentation therapy with inhaled alpha(1)-proteinase inhibitor.
3

Chemokines, G proteins and natural killer cells

88%
Maghazachi A. A.
Archivum Immunologiae et Therapiae Experimentalis
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2000
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vol. 48
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issue 2
65-72
EN
Natural killer (NK) cells are anti-tumor and anti-viral effector cells. Members of C, CC, CXC and CX3C chemokines induce the chemotaxis and enhance the cytotoxicity of NK cells, suggesting that these cells express receptors for chemokines. The ability of members of chemokines to inhibit the replication of HIV-1 strains, combined with the ability of the same chemokines to activate the anti-viral NK cells, provide compelling evidence for the role of NK cells in eradicating HIV-1 infection. In addition, chemokines induce various intracellular signaling pathways in NK cells, which include activation of the heterotrimeric, and perhaps the small guanine nucleotide binding (G) proteins, as well as the mobilization of intracellular calcium, among other activities. Further, chemokines induce the phosphorylation of chemokine receptors through the recruitment of G protein-coupled receptor kinases (GRKs) resulting in the desensitization and turning off the signals. In this review, I will update the knowledge of the effect of chemokines on NK cell motility and the signal transduction pathways induced by chemokines in these cells.
4

Biological activity of dendritic cells generated from cord blood CD34+ hematopoietic progenitors in IL-7- and IL-13-conditioned cultures

88%
Mytar B., Stec M., Weglarczyk K., Zembala M.
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2009
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vol. 59
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issue 1
67-74
EN
Introduction: Dendritic cells (DCs) are required for initiation of the immune response and may therefore be used for the production of cancer vaccines. As mature DCs (mDCs) are the most potent antigen-presenting cells, there is increasing interest in generating them ex vivo. The present study was designed to obtain mDCs from CD34+ hematopoietic progenitors by culturing them in different media. Materials and Methods: Cord blood CD34+ hematopoietic progenitors were expanded for 7 days in FST medium containing fms-related tyrosine kinase 3 ligand (Flt3-L), stem cell factor (SCF), and thrombopoietin (TPO). Then the cells were divided into three parts and cultured for 21 days in different media: FST medium or FST enriched in interleukin (IL)-3 (FST3 medium) or supplemented with IL-7 and IL-13 (FST713 medium). At the end of culture part of the cells was harvested, counted, and analyzed while the other part was matured with proinflammatory cytokines for 2 days. The cells' phenotypes, ability to induce proliferation of allogeneic lymphocytes in the mixed lymphocyte reaction (allo-MLR), chemotaxis, phagocytosis, and O2? production were determined. Results: The average fold increase of DCs at the end of culture in FST medium was 127, in FST3 1043, and in FST713 71. In comparison with the other media, FST713 medium supported the generation of mDCs that were characterized by higher expressions of CD83, costimulatory molecules, and HLA-DR, enhanced ability to induce allo-MLR and migration to macrophage inflammatory protein (MIP) 3?, poor phagocytosis, and O2? production. Conclusions: This study indicates that FST713 medium allows the generation of limited numbers of more mature DCs, while FST3 medium leads to the production of immature DCs in high numbers.
5

Reversible inhibition of movement in the amoebae Dictyostelium discoideum and its effect on chemoattractant recognition

63%
Waligorska A., Wianecka-Skocze? M., Korohoda W.
Folia Biologica
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2008
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vol. 56
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issue 3-4
123-133
EN
The cell fixatives formaldehyde and KMnO4 at low concentrations reversibly inhibit the movement of D. discoideum amoebae without directly interfering with cell viability. This inhibition of cell movement is accompanied by the decreased attachment of cells to substratum.When the tenacity and attachment of immobilized cells are artificially increased by compressing cells between two glass surfaces, the amoebae begin to move even in the presence of the fixatives. Amoebae starved for 24 hours, subjected to fixatives and a mineral salt solution in which they remained motionless, maintained chemotactic res acid and only after a few hours of active locomotion became reactive to cAMP.
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