Search results for "Immune system"
showing 10 items of 2885 documents
From microbiota toward gastro-enteropancreatic neuroendocrine neoplasms: Are we on the highway to hell?
2020
AbstractGut microbiota is represented by different microorganisms that colonize the intestinal tract, mostly the large intestine, such as bacteria, fungi, archaea and viruses. The gut microbial balance has a key role in several functions. It modulates the host’s metabolism, maintains the gut barrier integrity, participates in the xenobiotics and drug metabolism, and acts as protection against gastro-intestinal pathogens through the host’s immune system modulation. The impaired gut microbiota, called dysbiosis, may be the result of an imbalance in this equilibrium and is linked with different diseases, including cancer. While most of the studies have focused on the association between microb…
Abacavir and didanosine induce the interaction between human leukocytes and endothelial cells through Mac-1 upregulation
2010
Objective: Abacavir and didanosine are nucleoside reverse transcriptase inhibitors (NRTI) widely used in therapy for HIV-infection but which have been linked to cardiovascular complications. The objective of this study was to analyze the effects of clinically relevant doses of abacavir and didanosine on human leukocyte―endothelium interactions and to compare them with those of other NRTIs. Design and methods: The interactions between human leukocytes ― specifically peripheral blood polymorphonuclear (PMN) or mononuclear (PBMC) cells ― and human umbilical vein endothelial cells were evaluated in a flow chamber system that reproduces conditions in vivo. The expression of adhesion molecules wa…
Primary hypercholesterolemia and development of cardiovascular disorders: Cellular and molecular mechanisms involved in low-grade systemic inflammati…
2021
Primary hypercholesterolemia, a metabolic disorder characterized by elevated circulating levels of cholesterol products, mainly low-density lipoproteins, is associated with arteriosclerosis development. Cardiovascular disease, predominantly myocardial infarction and stroke, remains the main cause of death worldwide, with atherosclerosis considered to be the most common underlying pathology. In addition to elevated plasma levels of low-density lipoproteins, low-grade systemic inflammation and endothelial dysfunction seem to be the main drivers of premature atherosclerosis. Here we review current knowledge related to cellular and molecular mechanisms involved in low-grade systemic inflammatio…
2014
Extreme weather events such as summer heat waves become more frequent owing to global climate change and are predicted to alter disease dynamics. This is because high temperatures can reduce host immune function. Predicting the impact of climate change on host-parasite interactions is, however, difficult as temperature may also affect parasite infective stages and other host characteristics determining the outcome of interaction. Two experiments were conducted to investigate these phenomena in a Lymnaea stagnalis–Echinoparyphium aconiatum (Trematoda) interaction. In the first experiment, the effects of exposure of snails to experimental heat waves [maintenance at 25°C vs. 15°C (control)] wi…
Angiogenesis, immune system and growth factors: new targets in colorectal cancer therapy.
2005
Colorectal cancer is the second most common malignant human neoplasia. Over recent years, many efforts have been performed in order to develop and improve therapeutic protocols, and many advances have been accomplished in both the field of adjuvant and palliative therapy. Most of the chemotherapic agents currently used in the clinical setting are the products of decades of research aimed at inhibiting the uncontrolled growth of dysplastic cells. However, new frontiers in this field have recently been opened, with the identification of key molecules involved in physiologic mechanisms that are of fundamental importance for cancer development and progression. Tumor-induced angiogenesis, the ca…
Clinical and immunological aspects of microRNAs in neonatal sepsis
2022
Abstract Neonatal sepsis constitutes a highly relevant public health challenge and is the most common cause of infant morbidity and mortality worldwide. Recent studies have demonstrated that during infection epigenetic changes may occur leading to reprogramming of gene expression. Post-transcriptional regulation by short non-coding RNAs (e.g., microRNAs) have recently acquired special relevance because of their role in the regulation of the pathophysiology of sepsis and their potential clinical use as biomarkers. ~22-nucleotide of microRNAs are not only involved in regulating multiple relevant cellular and molecular functions, such as immune cell function and inflammatory response, but have…
Colorectal cancer defeating? Challenge accepted!
2013
Colorectal tumours are actually considered as aberrant organs, within it is possible to notice a different stage of cell growth and differentiation. Their origin is reported to arise from a subpopulation of tumour cells endowed with, just like the healthy stem cells, self-renewal and aberrant multi-lineage differentiation capacity likely to be called colorectal cancer stem cells (CCSCs). Cancer stem cells (CSCs) fate, since their origin, reflects the influences from their microenvironment (or niche) both in the maintenance of stemness, in promoting their differentiation, and in inducing epithelial-mesenchymal transition, responsible of CSCs dissemination and subsequent formation of metastat…
Fully synthetic self-adjuvanting thioether-conjugated glycopeptide-lipopeptide antitumor vaccines for the induction of complement-dependent cytotoxic…
2012
Glycopeptides of tumor-associated mucin MUC1 are promising target structures for the development of antitumor vaccines. Because these endogenous structures were weakly immunogenic, they were coupled to immune-response-stimulating T-cell epitopes and the Pam(3)Cys lipopeptide to induce strong immune responses in mice. A new thioether-ligation method for the synthesis of two- and three-component vaccines that contain MUC1 glycopeptides as the B-cell epitopes, a T-cell epitope peptide, and the Pam(3)CSK(4) lipopeptide is described. The resulting fully synthetic vaccines were used for the vaccination of mice, either in a liposome with Freund's adjuvant or in aqueous PBS buffer. The three-compon…
A rapid rosetting method for separation of hemocyte sub-populations of Drosophila melanogaster.
2003
Hemocytes, cellular elements of the innate immune system in insects, play a crucial role in the cellular and humoral immune response. Although a significant amount of information has been collected on their differentiation and function, our understanding of hemocyte development is far from complete. Their characterisation is mostly based on morphological criteria. However, molecular markers were recently identified, defining functional subsets by the aid of monoclonal antibodies. Isolated subsets of hemocytes, in sufficient quantity and purity could help to analyse their development in vitro and also to further define their molecular characteristics. Here we describe an antibody-based roset…
Quantitative contributions of IgG, IgM and C3 to erythrophagocytosis and rosette formation by peritoneal macrophages, and anti-opsonin activity of de…
1976
In vitro phagocytosis by guinea pig peritoneal macrophages of immune complexes (EA) was shown to be dependent on IgG antibody in a dose-dependent fashion. C3b enhanced phagocytosis of EA at limited IgG antibody concentrations only. When IgM antibody was used for sensitization of sheep red blood cells (SRBC), phagocytosis and rosette formation did not occur in the absence of bound C3. The polyanion, dextran sulfate 500 (DS), was shown to depress both rosette formation and phagocytosis of EAIgG, C1423 and EAIgMC1423, as well as immune adherence of human group 0 erythrocytes and hemolytic activity of C3. This effect of DS was seen only when it was actually present in the incubation medium.