Malaria starts with Plasmodium sporozoites infection of the host's liver, where development into blood stage parasites occurs. It is not clear why natural infections do induce protection against initial liver and generate low CD8+ T cell responses. Using a rodent malaria model, we show that suppresses immune responses were induced stage. Blood affects dendritic (DC) functions, inhibiting maturation capacity to initiate inverting interleukin (IL)-12/IL-10 secretion pattern. The interaction...

Abstract The phospholipid mediator sphingosine 1-phosphate (S1P) enhances motility and endocytosis of mature dendritic cells (DCs). We show that in vitro migration Swap-70−/− bone marrow-derived DCs (BMDCs) response to S1P S1P-induced upregulation are significantly reduced. S1P-stimulated movement BMDCs, specifically retraction their trailing edge, a collagen three-dimensional environment is impaired. These observations correlate with delayed entry into lymphatic vessels lymph nodes skin...

During an acute blood-stage malaria infection, T cell responses to and other bystander antigens are inhibited. Plasmodium infection induces strong cytokine that facilitate parasite clearance but may interfere with functions, as some of the soluble immune mediators induced also general inhibitors responses. Using a mouse model, we have analyzed cytokines produced by dendritic cells in response P. yoelii potential inhibitory activity. We found during DC migrate spleen secrete TGF-beta,...

Osteoclasts are bone resorbing cells acting as key mediators of disorders. Upon adhesion to bone, osteoclasts polarize and reorganize their cytoskeleton generate a ring-like F-actin-rich structure, the sealing zone, wherein osteoclast's resorptive organelle, ruffled border, is formed. The dynamic self-organization actin-rich adhesive structures, podosomes, from clusters belts crucial for osteoclast-mediated degradation. Mice lacking protein SWAP-70 display an osteopetrotic phenotype due...

Spontaneous maturation observed in dendritic cell (DC) cultures has been linked to their capacity induce immune responses. Despite several recent studies, the mechanisms and signals triggering spontaneous of DCs are largely unknown. We found that absence SWAP-70 causes spleen- bone marrow-derived and, vivo, spleen-resident CD11c(+)CD11b(+)CD8α(-) DCs. Activation markers, cross-presentation exogenous Ags, activation CD8(+) T cells much increased Swap-70(-/-) depends on cell-cell contact does...

Abstract Background Infection with Plasmodium is the cause of malaria, a disease characterized by high inflammatory response in blood. Dendritic cells (DC) participate both adaptive and innate immune responses, influencing generation responses. DC can be activated through different receptors, which recognize specific molecules microbes induce maturation DC. Methods Using yoelii , rodent malaria model, effect -infected erythrocytes on TLR responses have been analysed. Results It was found...

Abstract Background Infection with the protozoan parasite Plasmodium is cause of malaria. infects host erythrocytes causing pathology disease. -infected can modulate maturation dendritic cells (DCs) and alter their capacity to activate T cells. Methods Mice infected yoelii isolated P. were used study effect on mouse Results DCs are not able mature in response LPS injection during late stage infection mice, indicating impaired functionality these vivo . yoelii- inhibit vitro a dose-dependent...

Abstract Background During infection, dendritic cells (DCs) encounter pathogenic microorganisms that can modulate their function and shape the T cell responses generated. process of activation, DCs establish strong, long-lasting interactions with naïve cells. Methods Using a mouse malaria model, CD4 + have been analysed. Results DCs, either incubated in vitro infected erythrocytes or isolated from mice, are able to present exogenous antigens by MHC-II, but not prolonged effective do induce...

The lytic functions of the complement system play an important role in control Gram-negative infections. Complement-resistant Escherichia coli LP1395 (O18) grown under normal conditions can survive bactericidal action present human serum. Towards elucidating mechanisms resistance, resistance E. low pH and presence citric acid was tested.E. becomes sensitive to after growth at 5. Complement could be restored when cells were transferred 7 media. However, this recovery greatly impaired media...

Abstract Lipids affect the membrane properties determining essential biological processes. Earlier studies have suggested a role of switch-activated protein 70 (SWAP-70) in lipid raft formation dendritic cells. We used lipidomics combined with genetic and biochemical assays to analyze SWAP-70 dynamics. TLR activation using LPS as ligand represented pathogenic immunogenic stimulus, physical disruption cell–cell contacts tolerogenic stimulus. Physical disruption, but not LPS, caused an...

Abstract Although GM-CSF has been widely used in dendritic cell (DC) research, the mechanisms, factors, and signals regulating steady-state differentiation maturation of GM-CSF–dependent DCs are insufficiently known. We found that absence, individually or combined, related proteins DEF6 SWAP-70 strongly enhances murine GM-CSF–derived DCs. Contrasting SWAP-70, control through does not depend on RHOA activation. deficiency leads to expression DC-specific transcription factor ZBTB46 prolonged...