Tilmicosin is an antimicrobial agent used to treat intramammary infections against Staphylococcus aureus and has clinical anti-inflammatory effects. However, the mechanism by which it modulates the inflammatory process in the mammary gland is unknown. We evaluated the effect of tilmicosin treatment on the modulation of the mammary innate immune response after S.
View Article and Find Full Text PDFTGF-β type III receptor (TβRIII) is a co-receptor for TGFβ family members required for high-affinity binding of these ligands to their receptors, potentiating their cellular functions. TGF-βs, Bone Morphogenetic Proteins (BMP2/4) and Inhibins/Activins regulate different checkpoints during T cell differentiation. We have previously reported that TβRIII modulates T cell development by protecting developing thymocytes from apoptosis, however the role of this co-receptor in peripheral lymphocytes still remains elusive.
View Article and Find Full Text PDFAntibiotic resistant bacteria persist throughout the world because they have evolved the ability to express various defense mechanisms to cope with antibiotics and the immune system; thus, low-cost strategies for the treatment of these bacteria are needed, such as the usage of environmental minerals. This paper reports the antimicrobial properties of a clay collected from Brunnenberg, Germany, that is composed of ferroan saponite with admixtures of quartz, feldspar and calcite as well as exposed or hidden (layered at inner regions) nano Fe(0). Based on the growth curves (log phase) of six antibiotic resistant bacteria (4 gram-negative and 2 gram-positive), we concluded that the clay acted as a bacteriostat; however, the clay was only active against the gram-negative bacteria (except for resilient Klebsiella pneumonia).
View Article and Find Full Text PDFRegulatory T cells (Tregs) are considered key players in the prevention of allograft rejection in transplanted patients. Belatacept (BLT) is an effective alternative to calcineurin inhibitors that appears to preserve graft survival and function; however, the impact of this drug in the homeostasis of Tregs in transplanted patients remains controversial. Here, we analyzed the phenotype, function, and the epigenetic status of the Treg-specific demethylated region (TSDR) in FOXP3 of circulating Tregs from long-term kidney transplant patients under BLT or Cyclosporine A treatment.
View Article and Find Full Text PDFInhibins are members of the TGFβ superfamily, which regulate many cellular processes including differentiation, proliferation, survival and apoptosis. Although initially described as hormones regulating the hypothalamus-pituitary-gonadal axis, based on their ability to antagonize Activins, our group has recently reported that they play a role in thymocyte differentiation and survival, as well as in thymic stromal cell maturation and nTreg generation. Here, we used Inhibin knock out mice (Inhα-/-) to investigate the role of Inhibins in peripheral dendritic cell maturation and function.
View Article and Find Full Text PDFAirway inflammation is the most common hallmark of allergic asthma. Chemokine receptors involved in leukocyte recruitment are closely related to the pathology in asthma. CCR9 has been described as a homeostatic and inflammatory chemokine receptor, but its role and that of its ligand CCL25 during lung inflammation remain unknown.
View Article and Find Full Text PDFIn BALB/c adult mice, respiratory syncytial virus (RSV) infection enhances the degree of lung inflammation before and/or after ovalbumin (OVA) respiratory sensitization. However, it is unclear whether RSV infection in newborn mice has an effect on the immune response to OVA respiratory sensitization in adult mice. The aim of this study was to determine if RSV neonatal infection alters T CD4(+) population and lung inflammation during OVA respiratory sensitization in adult mice.
View Article and Find Full Text PDFCD5 has been mainly described as a negative regulator of TCR and BCR signaling and recent evidence has shown an important role for this receptor in delivering pro-survival signals. However, the molecular mechanisms underlying these processes remain unresolved. TCR crosslinking leads to phosphorylation of three tyrosine residues within the cytoplasmic tail of CD5 (Y429, Y441 and Y463) leading to the recruitment of signaling molecules like PI3K, c-Cbl and RasGAP; nevertheless, the role of these residues in T cell survival has not yet been assessed.
View Article and Find Full Text PDFChemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target.
View Article and Find Full Text PDFInhibins and Activins are members of the TGF-β superfamily that regulate the differentiation of several cell types. These ligands were initially identified as hormones that regulate the hypothalamus-pituitary-gonadal axis; however, increasing evidence has demonstrated that they are key regulators in the immune system. We have previously demonstrated that Inhibins are the main Activin ligands expressed in the murine thymus and that they regulate thymocyte differentiation, promoting the DN3-DN4 transition and the selection of SP thymocytes.
View Article and Find Full Text PDFProstaglandins Leukot Essent Fatty Acids
February 2015
Lipids are mainly solubilized by various families of lipid binding proteins which participate in their transport between tissues as well as cell compartments. Among these families, Hydrophobic Ligand Binding Proteins (HLBPs) deserve special consideration since they comprise intracellular and extracellular members, are able to bind a variety of fatty acids, retinoids and some sterols, and are present exclusively in cestodes. Since these parasites have lost catabolic and biosynthetic pathways for fatty acids and cholesterol, HLBPs are likely relevant for lipid uptake and transportation between parasite and host cells.
View Article and Find Full Text PDFThis study examined the role played by hypoxia-inducible factors (HIFs) in malignant phenotype maintenance and canonical Wnt signaling. Under normoxia, we determined that both HIF-1α and HIF-2α are expressed in human colon cancer cells but not in their non-malignant counterparts. The stable knockdown of HIF-1α or HIF-2α expression induced negative effects on the malignant phenotype of colon cancer cells, with lactate production, the rate of apoptosis, migration, CXCR4-mediated chemotaxis, and tumorigenic activity all being significantly affected by HIF knockdown and with HIF-1α depletion exerting greater effects.
View Article and Find Full Text PDFChemokines are small proteins that primarily regulate the traffic of leukocytes under homeostatic conditions and during specific immune responses. The chemokine-chemokine receptor system comprises almost 50 chemokines and approximately 20 chemokine receptors; thus, there is no unique ligand for each receptor and the binding of different chemokines to the same receptor might have disparate effects. Complicating the system further, these effects depend on the cellular milieu.
View Article and Find Full Text PDFThe estrogen receptor alpha (ERα) is a ligand-activated transcription factor that possesses two activating domains designated AF-1 and AF-2 that mediate its transcriptional activity. The role of AF-2 is to recruit coregulator protein complexes capable of modifying chromatin condensation status. In contrast, the mechanism responsible for the ligand-independent AF-1 activity and for its synergistic functional interaction with AF-2 is unclear.
View Article and Find Full Text PDFAllergic asthma is a chronic inflammatory disease characterized by the accumulation of eosinophils, Th2 cells and mononuclear cells in the airways, leading to changes in lung architecture and subsequently reduced respiratory function. We have previously demonstrated that CDIP-2, a chemokine derived peptide, reduced in vitro chemotaxis and decreased cellular infiltration in a murine model of allergic airway inflammation. However, the mechanisms involved in this process have not been identified yet.
View Article and Find Full Text PDFWe have previously shown that Jak3 is involved in the signaling pathways of CCR7, CCR9 and CXCR4 in murine T lymphocytes and that Jak3⁻/⁻ lymphocytes display an intrinsic defect in homing to peripheral lymph nodes. However, the molecular mechanism underlying the defective migration observed in Jak3⁻/⁻ lymphocytes remains elusive. Here, it is demonstrated for the first time, that Jak3 is required for the actin cytoskeleton reorganization in T lymphocytes responding to chemokines.
View Article and Find Full Text PDFBackground And Aims: Studies have reported differences in lung cancer behavior between sex and hormonal status that suggest a role of estrogens and estrogen receptor beta (ERβ) in lung carcinogenesis. In some types of hormone-dependent cancer, estrogens may regulate CXCL12/CXCR4 expression through ERβ signaling. High expression of CXCL12/CXCR4 is associated with poor prognosis in lung cancer because it promotes tumor growth and metastasis.
View Article and Find Full Text PDFCCL13/MCP-4, is a CC family chemokine that is chemoattractant for eosinophils, basophils, monocytes, macrophages, immature dendritic cells, and T cells, and its capable of inducing crucial immuno-modulatory responses through its effects on epithelial, muscular and endothelial cells. Similar to other CC chemokines, CCL13 binds to several chemokine receptors (CCR1, CCR2 and CCR3), allowing it to elicit different effects on its target cells. A number of studies have shown that CCL13 is involved in many chronic inflammatory diseases, in which it functions as a pivotal molecule involved in the selective recruitment of cell lineages to the inflamed tissues and their subsequent activation.
View Article and Find Full Text PDFBackground: Airway obstruction after antigen challenge is not always observed in patients with allergic asthma, even if they develop hyperresponsiveness. A similar event is observed in our guinea pig model of allergic asthma. Our aim was to study this phenomenon.
View Article and Find Full Text PDFCD5 functions as a negative regulator of TCR signaling during thymocyte development, however, the molecular mechanisms involved in this process remain elusive. A key molecule involved in the down modulation of TCR signaling is c-Cbl, an ubiquitin ligase that physically associates with CD5. Crosslinking of TCR in thymocytes leads to ubiquitylation and lysosomal/proteasomal degradation of TCR downstream signaling effectors and CD5 itself.
View Article and Find Full Text PDFTGF-β type III receptor (TβRIII) is a coreceptor for TGFβ family members required for high-affinity binding of these ligands to their receptors, potentiating their cellular functions. TGF-β [1]-[3], bone morphogenetic proteins (BMP2/4) and inhibins regulate different checkpoints during T cell differentiation. Although TβRIII is expressed on hematopoietic cells, the role of this receptor in the immune system remains elusive.
View Article and Find Full Text PDFBackground: The pathogenesis of allergic airway inflammation in asthmatic patients is complex and characterized by cellular infiltrates and activity of many cytokines and chemokines. Both the transcription factor hypoxia inducible factor-1 (HIF-1) and chemokine CCL2 have been shown to play pivotal roles in allergic airway inflammation. The interrelationship between these two factors is not known.
View Article and Find Full Text PDFAnalysis of the mechanisms underlying the inflammatory response in amoebiasis is important to understand the immunopathology of the disease. Mucosal associated effector and regulatory T cells may play a role in regulating the inflammatory immune response associated to Entamoeba histolytica infection in the colon. A subpopulation of regulatory T cells has recently been identified and is characterized by the expression of the chemokine receptor CCR9.
View Article and Find Full Text PDFTwo major subsets of human Mo are identified based on CD14 and CD16 expression: the classical CD16(-) Mo and the minor CD14(+)CD16(+) Mo. In vitro studies suggested distinct function and differentiation potential for each cell population. However, the in vivo relevance of these findings remains unclear.
View Article and Find Full Text PDFTrichinellosis is a public health problem and is considered an emergent/re-emergent disease in various countries. The etiological agent of trichinellosis is the nematode Trichinella, which infects domestic animals such as pigs and horses, as well as wild animals and humans. A veterinary vaccine could be an option to control the disease in domestic animals.
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